# Science et Vie

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## Les parutions sur ScienceDirect. Mot clé : "Muscle"

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• Proximity labeling: spatially resolved proteomic mapping for neurobiology
24 novembre 2017
Publication date: June 2018
Source:Current Opinion in Neurobiology, Volume 50

Author(s): Shuo Han, Jiefu Li, Alice Y Ting

Understanding signaling pathways in neuroscience requires high-resolution maps of the underlying protein networks. Proximity-dependent biotinylation with engineered enzymes, in combination with mass spectrometry-based quantitative proteomics, has emerged as a powerful method to dissect molecular interactions and the localizations of endogenous proteins. Recent applications to neuroscience have provided insights into the composition of sub-synaptic structures, including the synaptic cleft and inhibitory post-synaptic density. Here we compare the different enzymes and small-molecule probes for proximity labeling in the context of cultured neurons and tissue, review existing studies, and provide technical suggestions for the in vivo application of proximity labeling.

• Surgical Techniques of Using Direct Anterior Approach and Bridging Plate Fixation of Periprosthetic Fracture of an Arthrodesed Hip: A Case Report
24 novembre 2017
Publication date: June 2018
Source:Journal of Orthopaedics, Trauma and Rehabilitation, Volume 24

Author(s): Wong Hing-Cheong, Woo Siu-Bon

We present a case of a 65-year-old woman with traumatic periprosthetic fracture of left proximal femur with ipsilateral arthrodesed hip and cobra plate in-situ. It imposes challenges on achievement of stable fixation for fracture management and preservation of blood supply for fracture healing. Minimally invasive plate osteosynthesis through direct anterior approach was executed with intraoperative templating. Anterior bridging plating using pre-bent reverse distal femoral locking compression plate (less invasive stabilisation system) was performed successfully. The patient had a fracture union in 10 months and returned to the previous mobility status. This technique can achieve stable fixation and preservation of blood supply for fracture healing through minimal invasive technique.

• Fixation of Pelvic–Acetabular Fractures Using a Midline-Modified Stoppa Approach: Clinical and Operative Outcomes
24 novembre 2017
Publication date: June 2018
Source:Journal of Orthopaedics, Trauma and Rehabilitation, Volume 24

Author(s): Chan Kenneth Kin-yan, Chui King-him, Ip Ka-chun, Lee Kin-bong, Li Wilson

Background/Purpose This served as the first report from our locality to evaluate the modified Stoppa approach, via a low-midline wound, for treating pelvic–acetabular fractures. Methods A total of 17 polytrauma patients with pelvic and/or acetabular fractures were consecutively treated using the modified Stoppa approach. They were followed up for at least 1 year postoperatively for radiographic and clinical assessments, which included the Modified Merle d’Aubigne Score, Harris Hip Score, and pain visual analogue scale. Results Among the 17 patients, 11 had pelvic ring fractures, two had isolated acetabular fractures, and four had a combination of both. Excellent and anatomical reduction was achieved in 73.3% of pelvic fractures and 71.4% of acetabular fractures. Functional outcomes simulated a bimodal distribution. Age of patient and Injury Severity Score were significant predictors for functional results, whereas fracture characteristics and quality of reduction were not correlated with clinical outcomes in this series. We experienced a low complication rate. Conclusion Excellent exposure for fracture reduction and fixation with low complication rate was achieved with the modified Stoppa approach. We were encouraged by the results of this preliminary series for treating pelvic–acetabular fractures in polytrauma patients.

• Primary Ewing's Sarcoma of the Spine with Conus Medullaris Syndrome
24 novembre 2017
Publication date: June 2018
Source:Journal of Orthopaedics, Trauma and Rehabilitation, Volume 24

Author(s): Jayant Kumar Laik, Ritesh Kumar

Ewing's sarcoma (ES) is a primary neoplasm of the bone affecting age groups in the second decade of life. It commonly affects the metaphyseal ends of growing bones. Primary ES of the spine is rare and is commonly seen in the sacrum. The incidence of sacral ES in the spine is &lt;5% whereas that of nonsacral ES is &lt;0.9%. A high index of suspicion is needed to diagnose the condition and prompt surgical intervention combined with chemotherapy and radiotherapy treatment is needed to contain the progression of neurological deficit. We report a case of primary ES with sudden onset conus medullaris compression in a 17-year-old female.

• Does Conservative Rehabilitation Program Lead to Long-Term Stiffness after Arthroscopic Rotator Cuff Repair?
24 novembre 2017
Publication date: June 2018
Source:Journal of Orthopaedics, Trauma and Rehabilitation, Volume 24

Author(s): Chun Ming Chan, Pang Hei Li

Background Evidence on the ideal rehabilitation program for arthroscopic rotator cuff repair is lacking. Most data and results are conflicting with no consensus made. This study aims to compare between an early aggressive program with immediate postoperative range-of-motion (ROM) exercises and a more conservative program with early restriction of motion in Hong Kong Chinese population. Materials and methods We retrospectively evaluated 37 arthroscopic rotator cuff repair cases who underwent a standardized delayed rehabilitation protocol of immobilization for 4 weeks to 6 weeks before formal passive ROM exercises. Patients were evaluated at 3 months, 6 months, and 12 months after the surgery, for which they would be tested on passive forward flexion (FF). They were categorized as “stiff” if FF was less than 100°. Constant score, Disability of Arm, Shoulder and Hand (DASH) score, Visual Analog Scale (VAS) score, and isometric abduction power deficit percentage were parameters to assess the functional outcome, and they were obtained in all of the patients' last follow-up assessments. Results Two cases (5.4%) are considered “stiff” 6 months after the surgery. At 1 year, the stiffness in both cases resolved, resulting in 0% rate of stiffness. The mean FF at 1 year was 153.33 ± 20.15, which is comparable to the literature. Two cases (5.4%) of clinical retear occurred. Mean Constant score at the latest follow-up was 62.4 ± 13.2. Mean VAS score was 1.1 ± 1.8 at rest and 2.8 ± 2.0 on exertion. Mean DASH score was 25.3 ± 21.9. Mean isometric abduction power deficit was 42.7% ± 0.2%. Discussion Historically, due to concerns on long-term stiffness, an early aggressive postoperative rehabilitation protocol was used. We found that an early restriction of ROM with 4 weeks to 6 weeks of immobilization did not lead to long-term stiffness and functional disadvantage. This includes patients with stiffness even before the operations. Conclusions Immobilization for 4 weeks to 6 weeks after arthroscopic rotator cuff repair does not result in long-term stiffness and may even be beneficial to cuff tendon healing.

• Absence of the subclavius muscle with contralateral subclavius posticus muscle: first imaging report
24 novembre 2017
Publication date: May–June 2018
Source:Clinical Imaging, Volume 49

Author(s): Yun Sam, Sekyoung Park, Chang Su Kim

We present a case of a 56-year-old man with pain in in his right anterior shoulder, arm, and hand. MRI studies demonstrated absence of the subclavius muscle with contralateral subclavius posticus muscle. To our knowledge, imaging of the total absence of subclavius muscle has not been previously described. Understanding and recognition of subclavius posticus muscle are important for its potential role in thoracic outlet syndrome.

• Imaging findings in systemic childhood diseases presenting with dermatologic manifestations
24 novembre 2017
Publication date: May–June 2018
Source:Clinical Imaging, Volume 49

Author(s): Adam Z. Fink, Julia K. Gittler, Radhika N. Nakrani, Jonathan Alis, Einat Blumfield, Terry L. Levin

Purpose Many childhood diseases often present with skin abnormalities with which radiologists are largely unfamiliar. Knowledge of associated dermatologic manifestations may aid the radiologist in confirming the diagnosis and recommending targeted imaging of affected organs. Methods We review the imaging findings in childhood diseases associated with dermatologic manifestations. Findings Diseases include dermatologic findings which herald underlying malignancy (Neuroblastoma, leukemia/lymphoma, Langerhans cell histiocytosis),are associated with risk of malignancy (Epidermolysis Bullosa, basal cell nevus syndrome, Cowden's syndrome, Tuberous Sclerosis),or indicate a systemic inflammatory/immune disorder (Kawasaki's disease, Henoch Schonlein Purpura, systemic lupus erythematosus, scleroderma, sarcoidosis, dermatomyositis and immune thrombocytopenic purpura). Conclusion Familiarity with pertinent findings in childhood diseases presenting with dermatologic manifestations in childhood diseases aids the radiologist in confirming the diagnosis and guiding imaging workup.

• Multistage fusion approaches based on a generative model and multivariate exponentially weighted moving average for diagnosis of cardiovascular autonomic nerve dysfunction
24 novembre 2017
Publication date: May 2018
Source:Information Fusion, Volume 41

Author(s): Mohammad Mehedi Hassan, Shamsul Huda, John Yearwood, Herbert F. Jelinek, Ahmad Almogren

Like many medical diagnoses, clinical decision support system (CDSS) is essential to diagnose the cardiovascular autonomic neuropathy (CAN). However, diagnosis of CAN using the traditional ‘Ewing battery test’ becomes very difficult due to the inherent imbalanced and incompleteness condition in the collected clinical data. This influences the health professionals to investigate other related diagnostic reports of patients, including Electrocardiogram (ECG) data from ECG sensors, blood chemistry, podiatry and endocrinology features. However, additional components increase the dimensionality of the feature set as well as its heterogeneity and modality in the clinical data which may limit the applications of traditional data mining approaches for an accurate diagnosis of CAN in the CDSS. To address the aforementioned problem, in this paper, we have proposed, a novel multistage fusion approach based on a generative model and a statistical process control (SPC) technique to diagnose CAN more accurately. The proposed approach develops two different generative models by using a shared and a separated Independent Component Analysis (ICA) to overcome the incompleteness and modality of the data. Due to the heterogeneous and non-normality features, statistical correlations and multivariate control limits in relation to the CAN diagnosis parameters are determined by fusioning of a series of exponentially weighted moving average (MEWMA) control processes. Fusioned features from both component analyses and SPC are applied in an ensemble classification system. The proposed multistage fusion approach is experimentally verified to justify its performance by using a large dataset collected from the diabetes screening research initiative (DiScRi) project at Charles Sturt University, NSW, Australia. Our comprehensive experimental results show that the proposed fusion approach performs better than the standard classifier for both ‘Ewing’ feature set and ‘Ewing and additional feature set’ with significant improvement in accuracy.

• A tutorial review on entropy-based handcrafted feature extraction for information fusion
24 novembre 2017
Publication date: May 2018
Source:Information Fusion, Volume 41

Author(s): Rodrigo Capobianco Guido

Entropy (H) is the main subject of this article, concisely written to serve as a tutorial introducing two feature extraction (FE) methods for usage in digital signal processing (DSP) and pattern recognition (PR). The theory, carefully exposed, is supplemented with numerical cases, augmented with C/C++ source-codes and enriched with example applications on restricted-vocabulary speech recognition and image synthesis. Complementarily and as innovatively shown, the ordinary calculation of H corresponds to the outcome of a partially pre-tuned deep neural network architecture which fuses important information, bringing a cutting-edge point-of-view for both DSP and PR communities.

• Development of citric anhydride anchored mesoporous MOF through post synthesis modification to sequester potentially toxic lead (II) from water
24 novembre 2017
Publication date: 1 May 2018
Source:Microporous and Mesoporous Materials, Volume 261

Author(s): Ayoub Abdullah Alqadami, Moonis Ali Khan, Masoom Raza Siddiqui, Zeid Abdullah Alothman

Here in, a post synthesis modification (PSM) approach was adopted for anchoring citric anhydride (CA) with NH2-MIL-53(Al) through covalent linkage between amino (–NH2) group of NH2-MIL-53(Al) and carboxylic group of CA to develop mesoporous amide citric anhydride [AMCA-MIL-53(Al)] metal organic framework (MOF) and its potential application in sequestering toxic lead [Pb(II)] from aqueous phase was tested. Characterization studies affirmed successful AMCA-MIL-53(Al) formation. Experimental parameters viz., pH, contact time, Pb(II) concentration, temperature, and AMCA-MIL-53(Al) dose have a profound influence on adsorption. The maximum adsorption of Pb(II) on AMCA-MIL-53(Al) was 390 mg/g, observed at 318 K. Modeling studies revealed fitting of Langmuir isotherm and Lagergren's pseudo-first-order kinetic models to experimental data. Mechanistically, the adsorption was governed by amide and carboxylate groups through coordinate and electrostatic bonds formations. Desorption studies showed 79.5% (maximum) Pb(II) recovery with 0.1 M HCl. Thus, it could be concluded that the developed AMCA-MIL-53(Al) MOF is an excellent adsorbent for an efficient and rapid Pb(II) removal and recovery.

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• Analytical methods used for the authentication of food of animal origin
24 novembre 2017
Publication date: 25 April 2018
Source:Food Chemistry, Volume 246

Author(s): Ouissam Abbas, Manuela Zadravec, Vincent Baeten, Tomislav Mikuš, Tina Lešić, Ana Vulić, Jelena Prpić, Lorena Jemeršić, Jelka Pleadin

Since adulteration can have serious consequences on human health, it affects market growth by destroying consumer confidence. Therefore, authentication of food is important for food processors, retailers and consumers, but also for regulatory authorities. However, a complex nature of food and an increase in types of adulterants make their detection difficult, so that food authentication often poses a challenge. This review focuses on analytical approaches to authentication of food of animal origin, with an emphasis put on determination of specific ingredients, geographical origin and adulteration by virtue of substitution. This review highlights a current overview of the application of target approaches in cases when the compound of interest is known and non-target approaches for screening issues. Papers cited herein mainly concern milk, cheese, meat and honey. Moreover, advantages, disadvantages as well as challenges regarding the use of both approaches in official food control but also in food industry are investigated.

• Chemical constituents, antioxidant and gastrointestinal transit accelerating activities of dried fruit of Crataegus dahurica
24 novembre 2017
Publication date: 25 April 2018
Source:Food Chemistry, Volume 246

Author(s): Xinrui Wang, Changlong Zhang, Yajie Peng, Haimin Zhang, Zhigang Wang, Yang Gao, Ying Liu, Hailong Zhang

Crataegus dahurica Koehne is an edible wild fruit mainly distributed in Northeast China. The purpose of this study was to elucidate the chemical constituents and investigate the bioactivities of dried fruit of C. dahurica methanol extract (CdME). Through various chromatographic methods, thirty-five compounds were isolated from CdME for the first time and their structures were identified on the basis of physicochemical properties and spectroscopic data. The main structural types of these compounds were triterpenoids and polyphenolics. Pharmacological experiments results showed that CdME had potently antioxidant capacity and ethyl acetate fraction was the active part with the greatest antioxidant activities. Moreover, CdME especially n-butanol fraction significantly accelerated the gastrointestinal transit in mice (acceleration rate: 78.5 ± 1.5% vs. 69.9 ± 3.2% at a dose of 250 mg/kg, compared to the control group, P &lt; .01). On the basis of these results, C. dahurica may be considered as a good resource of antioxidants and digestion-improving agents.

• Application of next generation semiconductor based sequencing for species identification in dairy products
24 novembre 2017
Publication date: 25 April 2018
Source:Food Chemistry, Volume 246

Author(s): Anisa Ribani, Giuseppina Schiavo, Valerio Joe Utzeri, Francesca Bertolini, Claudia Geraci, Samuele Bovo, Luca Fontanesi

In this study, we applied a next generation sequencing (NGS) technology (Ion Torrent) for species identification based on three mitochondrial DNA (mtDNA) regions amplified on DNA extracted from dairy products. Sequencing reads derived from three libraries, obtained from artificial DNA pools or from pooled amplicons, were used to test the method. Then, sequencing results from five libraries obtained from two mixed goat and cow milk samples, one buffalo mozzarella cheese, one goat crescenza cheese and one artisanal cured ricotta cheese, were able to detect all expected species in addition to undeclared species in a few of them. Mining generated reads it was possible to identify different dairy species mitotypes and the presence of human DNA that could constitute a potential marker to monitor the hygienic level of dairy products. Overall results demonstrated the usefulness of NGS for species identification in food products and its possible application for food authentication.

• Effect of different stunning methods on antioxidant status, in vivo myofibrillar protein oxidation, and the susceptibility to oxidation of silver carp (Hypophthalmichthys molitrix) fillets during 72 h postmortem
24 novembre 2017
Publication date: 25 April 2018
Source:Food Chemistry, Volume 246

Author(s): Longteng Zhang, Qian Li, Shiliang Jia, Zhan Huang, Yongkang Luo

This study aimed to evaluate the effects of different stunning methods (percussion, T1; immersion in ice/water slurry, T2; gill cut, T3) on antioxidant status, in vivo myofibrillar protein (MP) oxidation, and the susceptibility to postmortem oxidation (induced by hydroxyl radical oxidizing system) of silver carp (Hypophthalmichthys molitrix) fillets. Stress conditions, antioxidant enzyme activities, and protein oxidation parameters were analyzed during 72 h postmortem. The results indicated that the strongest stress conditions in the T3 group led to impaired glutathione peroxidase (GPx) and total superoxide dismutase (T-SOD) activity, and significantly (P &lt; .05) higher carbonyl concentrations, thereby promoted in vivo MP oxidation of fillets. The T3 group also showed severe losses in myosin heavy chain (MHC) intensities and sulfhydryl groups at higher H2O2 concentrations. Overall, fillets from the T3 group were more susceptible to oxidative damage, and the T1 and T2 groups maintained better quality in terms of lower MP oxidation rates.

• Optimization of sample preparation by central composite design for multi-class determination of veterinary drugs in bovine muscle, kidney and liver by ultra-high-performance liquid chromatographic-tandem mass spectrometry
24 novembre 2017
Publication date: 25 April 2018
Source:Food Chemistry, Volume 246

Author(s): Tiele M. Rizzetti, Maiara P. de Souza, Osmar D. Prestes, Martha B. Adaime, Renato Zanella

In this study a simple and fast multi-class method for the determination of veterinary drugs in bovine liver, kidney and muscle was developed. The method employed acetonitrile for extraction followed by clean-up with EMR-Lipid® sorbent and trichloracetic acid. Tests indicated that the use of TCA was most effective when added in the final step of the clean-up procedure instead of during extraction. Different sorbents were tested and optimized using central composite design and the analytes determined by ultra-high-performance liquid chromatographic-tandem mass spectrometry (UHPLC-MS/MS). The method was validated according the European Commission Decision 2002/657 presenting satisfactory results for 69 veterinary drugs in bovine liver and 68 compounds in bovine muscle and kidney. The method was applied in real samples and in proficiency tests and proved to be adequate for routine analysis. Residues of abamectin, doramectin, eprinomectin and ivermectin were found in samples of bovine muscle and only ivermectin in bovine liver.

• One-pot preparation of hydrophilic manganese oxide nanoparticles as T1 nano-contrast agent for molecular magnetic resonance imaging of renal carcinoma in vitro and in vivo
24 novembre 2017
Publication date: 15 April 2018
Source:Biosensors and Bioelectronics, Volume 102

Author(s): Jingjing Li, Chen Wu, Pingfu Hou, Min Zhang, Kai Xu

Magnetic resonance imaging (MRI) contrast agents have become a necessary part for clinical practice to improve the sensitivity for the diagnosis of small lesions and injuries. Among them, manganese oxide nanoparticle (MnO NPs)-based MRI contrast agent attracts more and more attention because of their better performance in the detection of brain disease and positive enhancement in T1-weighted image. However, the relatively low r1 relaxivity and complex synthetic route hampered their wider applications. In this work, we proposed a one-pot approach to prepare hydrophilic MnO NPs via a polyol-like method with poly (ethylene glycol) (PEG) as both a solvent and surfactant. The obtained PEG-MnO NPs displayed a high T1 relaxivity and a low r2/r1 ratio (12.942s−1 mM−1 and 4.66) at 3.0T, which was three times that of the clinical used contrast agent, Magnevist (Gd-DTPA). Additionally, when exposed to the simulated body fluid (SBF), acidic environment or glutathione, PEG-MnO NPs kept stable, favoring their further biological applications. Then, to explore their use for the molecular magnetic resonance imaging of 786-0 renal carcinoma, amino group modified AS1411 aptamer as the targeting molecule was introduced to conjugate with PEG-MnO NPs via covalent coupling reaction. The fabricated nanoprobe, AS1411-PEG-MnO, could clearly visualize 786-0 renal carcinoma cells with MRI in vitro. Furthermore, compared with PEG-MnO NPs, AS1411-PEG-MnO nanoprobe presented a prolonged retention in 786-0 renal carcinoma tumor in vivo. The intravenously injected nanoprobes were eventually excreted from the body through the renal clearance route. These results indicated the potential promising of PEG-MnO NPs as an alternative contrast agent in MRI scanning.

• Cascaded signal amplification via target-triggered formation of aptazyme for sensitive electrochemical detection of ATP
24 novembre 2017
Publication date: 15 April 2018
Source:Biosensors and Bioelectronics, Volume 102

Author(s): Xia Li, Jianmei Yang, Jiaqing Xie, Bingying Jiang, Ruo Yuan, Yun Xiang

The construction of reliable sensors for adenosine triphosphate (ATP) detection gains increasing interest because of its important roles in various enzymatic activities and biological processes. Based on a cascaded, significant signal amplification approach by the integration of the aptazymes and catalytic hairpin assembly (CHA), we have developed a sensitive electrochemical sensor for the detection of ATP. The target ATP leads to the conformational change of the aptazyme sequences and their association with the hairpin substrates to form active aptazymes, in which the hairpin substrates are cyclically cleaved by the metal ion cofactors in buffer to release the enzymatic sequences that can also bind the hairpin substrates to generate active DNAzymes. The catalytic cleavage of the hairpin substrates in the aptazymes/DNAzymes thus results in the generation of a large number of intermediate sequences. Subsequently, these intermediate sequences trigger catalytic capture of many methylene blue-tagged signal sequences on the electrode surface through CHA, producing significantly amplified current response for sensitive detection of ATP at 0.6nM. Besides, the developed sensor can discriminate ATP from analogous interference molecules and be applied to human serum samples, making the sensor a useful addition to the arena for sensitive detection of small molecules.

• A molecularly imprinted electrochemiluminescence sensor based on upconversion nanoparticles enhanced by electrodeposited rGO for selective and ultrasensitive detection of clenbuterol
24 novembre 2017
Publication date: 15 April 2018
Source:Biosensors and Bioelectronics, Volume 102

Author(s): Xincui Jin, Guozhen Fang, Mingfei Pan, Yukun Yang, Xiaoyun Bai, Shuo Wang

A simple, efficient and sensitive molecularly imprinted electrochemiluminescence sensor (MIECLS) based on reduced graphene oxide (rGO) and upconversion nanoparticles (UCNPs) was developed for determination of clenbuterol (CLB). In this study, rGO generated by electrodeposition of graphene oxide not only acted as carrier for immobilizing UCNPs, but also had a significant impact in boosting electrochemiluminescence (ECL) response of UCNPs thanks to its high conductivity, superior electron transport rate and large specific surface area. UCNPs as an advanced ECL emitter possessed wonderful ECL performance. Furthermore, the introduction of molecularly imprinted polymers (MIP) endowed the ECL sensor a new character of specifically identifying analyte CLB. Under the optimal experimental conditions, the ECL signal was proportional to the logarithm of CLB concentration in the range of 10nM to 100µM with a low detection limit of 6.3nM. The proposed MIECLS combining the advantages of UCNPs-ECL and MIP exhibited good sensitivity, desirable selectivity and favorable stability, indicating enormous potential in the future of food safety detection.

• Immunomodulatory and anticancer protein hydrolysates (peptides) from food proteins: A review
24 novembre 2017
Publication date: 15 April 2018
Source:Food Chemistry, Volume 245

Author(s): Meram Chalamaiah, Wenlin Yu, Jianping Wu

Bioactive peptides are oligopeptides that consist of 2–20 amino acids that can exert beneficial effects on human health in addition to basic nutritional effects. Food derived protein hydrolysates or peptides with immunomodulatory and anticancer activities have been reported from a variety of food protein sources such as milk, egg, fish, rice, soybean, pea, chlorella, spirulina, oyster and mussel. In vitro hydrolysis of food proteins using commercial proteolytic enzymes is the most commonly employed process for the production of immunomodulatory and anticancer food protein hydrolysates. The immunomodulatory and anticancer activities of food derived protein hydrolysates or peptides are related to the amino acid composition, sequence and length. Most immunomodulatory and anticancer food protein hydrolysates or peptides were tested using cell culture and animal models, while a few involved clinical trials. This review provides a comprehensive overview of immunomodulatory and anticancer food derived protein hydrolysates or peptides, their production and mechanisms of action.

• Matrix-effect free multi-residue analysis of veterinary drugs in food samples of animal origin by nanoflow liquid chromatography high resolution mass spectrometry
24 novembre 2017
Publication date: 15 April 2018
Source:Food Chemistry, Volume 245

Author(s): Jaime Alcántara-Durán, David Moreno-González, Bienvenida Gilbert-López, Antonio Molina-Díaz, Juan F. García-Reyes

In this work, a sensitive method based on nanoflow liquid chromatography high-resolution mass spectrometry has been developed for the multiresidue determination of veterinary drugs residues in honey, veal muscle, egg and milk. Salting-out supported liquid extraction was employed as sample treatment for milk, veal muscle and egg, while a modified QuEChERS procedure was used in honey. The enhancement of sensitivity provided by the nanoflow LC system also allowed the implementation of high dilution factors as high as 100:1. For all matrices tested, matrix effects were negligible starting from a dilution factor of 100, enabling, thus, the use of external standard calibration instead of matrix-matched calibration of each sample, and the subsequent increase of laboratory throughput. At spiked levels as low as 0.1 or 1 µg kg−1 before the 1:100 dilution, the obtained signals were still significantly higher than the instrumental limit of quantitation (S/N 10).

• Simultaneous determination of heat stable peptides for eight animal and plant species in meat products using UPLC-MS/MS method
24 novembre 2017
Publication date: 15 April 2018
Source:Food Chemistry, Volume 245

Author(s): Yingying Li, Yingying Zhang, Huichen Li, Wentao Zhao, Wenping Guo, Shouwei Wang

Food adulteration and fraud is driven by economic interests; it is thus necessary to establish a high-through method that allows quantitative identification of familiar animal and plant proteins for global use. In this study, a sensitive mass spectrometric approach for the detection of eight species, including pork, beef, lamb, chicken, duck, soy, peanut, and pea, is presented and the heat stability and specificity of screened peptides are verified. To improve screening efficiency of specific peptides, several key data searching parameters, including peptides, sequence lengths, sequence coverage, and unique peptides, are investigated. Using this approach, it is possible to detect a 0.5% contamination of any of the eight species. The method is proven to have high sensitivity, specificity, repeatability, and a low quantitative detection limit with respect to adulteration of diverse types of meat products.

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• Dephosphorylation enhances postmortem degradation of myofibrillar proteins
24 novembre 2017
Publication date: 15 April 2018
Source:Food Chemistry, Volume 245

Author(s): Zheng Li, Meng Li, Manting Du, Qingwu W. Shen, Dequan Zhang

Protein degradation is primarily responsible for postmortem meat tenderization, which might be affected by phosphorylation. The objective of this study was to investigate the effect of phosphorylation on myofibrillar proteins degradation in muscle during postmortem. Here we modulated the phosphorylation status of protein by protein kinase inhibitor and phosphatase inhibitor, and the effect of these inhibitors on myofibrillar protein degradation was evaluated. Generally, myofibril fragmentation index of samples with lower phosphorylation level was higher. Troponin T and heat shock protein 27 were degraded faster in protein kinase inhibited (low phosphorylation level) muscle, compared with the other two groups, while the degradation of desmin was not affected by inhibitors. Meanwhile, myosin heavy chain, actin and tropomyosin showed limited degradation in postmortem muscle. This study showed that dephosphorylation enhances the degradation of some myofibrillar proteins, indicating that protein phosphorylation may play an important role in postmortem meat tenderization.

• Effect of kappa-carrageenan oligosaccharides on myofibrillar protein oxidation in peeled shrimp (Litopenaeus vannamei) during long-term frozen storage
24 novembre 2017
Publication date: 15 April 2018
Source:Food Chemistry, Volume 245

Author(s): Bin Zhang, Chuan-dong Fang, Gui-juan Hao, Yang-yang Zhang

Protein oxidation during chilling and frozen storage has recently attracted great attention due to its consequences on protein solubility and functionality. In this study, the effects of kappa-carrageenan oligosaccharides on myofibrillar protein oxidation in peeled shrimp (Litopenaeus vannamei) during frozen storage were investigated by assessing the content of the carbonyls, total sulfhydryl, dityrosine, and surface hydrophobicity. We also examined the means of antioxidant activity in vitro, degradation of muscle proteins, and integrity of tissue structure. Our data revealed that in vitro carrageenan oligosaccharides exhibited good capacities of OH , O2 , and DPPH· scavenging and Fe2+-chelating activity. Chemical analyses showed that frozen storage increased susceptibility of myofibrillar proteins to frozen oxidation. We found that the incorporation of carrageenan oligosaccharides during the treatment of the shrimp prior to frozen storage significantly decreased the formation of protein carbonyl and dityrosine, lowered the changes in myofibrillar surface hydrophobicity, and maintained a higher total sulfhydryl content when compared with the water-treated samples (control). Additionally, the results of protein degradation and tissue structure confirmed that these antioxidant oligosaccharides exhibited marked effects on stability of muscle proteins and effectively inhibited the degradation/oxidation of muscle proteins during frozen storage. Overall, the contribution of the antioxidant activities played an important role in cryoprotective effects of carrageenan oligosaccharides on frozen shrimp. Further application of these findings might maintain better quality and extend the commercialization of refrigerated products.

• Effects of (−)-epigallocatechin-3-gallate incorporation on the physicochemical and oxidative stability of myofibrillar protein–soybean oil emulsions
24 novembre 2017
Publication date: 15 April 2018
Source:Food Chemistry, Volume 245

Author(s): Yungang Cao, Nasi Ai, Alma D. True, Youling L. Xiong

The dose-dependent effects of (−)-epigallocatechin-3-gallate (EGCG; at 0, 50, 100, 200, 500, and 1000 mg/L) on the physical, chemical, and oxidative stability of porcine myofibrillar protein (MP)–soybean oil emulsion systems were investigated. The results showed EGCG at all levels effectively suppressed lipid oxidation in MP emulsion composite gels during the entire chill storage (at 4 °C for 0, 3, or 7 days). The incorporation of EGCG at higher concentrations (&gt;100 mg/L) promoted the loss of sulfhydryls, reduction of surface hydrophobicity, and aggregation and cross-linking of MP. As a result, high concentrations of EGCG (500 and 1000 mg/L) hampered emulsification and gel formation of MP. However, EGCG at lower concentrations (50–200 mg/L) improved the oxidative stability of meat emulsions without jeopardizing the textural stability.

• Bioaccessibility of four calcium sources in different whey-based dairy matrices assessed by in vitro digestion
24 novembre 2017
Publication date: 15 April 2018
Source:Food Chemistry, Volume 245

Author(s): Lucie Lorieau, Linda Le Roux, Frédéric Gaucheron, Amandine Ligneul, Etienne Hazart, Didier Dupont, Juliane Floury

Numerous calcium sources are available to enrich food, but their behavior during digestion is still unknown. This study focused on the influence of the gastro-intestinal pH, the food structure and the calcium source on the bioaccessibility of the nutrient. Four calcium sources were studied: calcium carbonate, calcium citrate malate, calcium phosphate and calcium bisglycinate. These were added to dairy matrices, containing cream and whey proteins, of different forms (liquid or gel). The kinetics of solubility and ionic calcium concentration during in vitro digestion were studied, as function of gastro-intestinal pH. All calcium sources were almost fully soluble in the gastric compartment, and then became insoluble in the intestinal phase. The level of calcium insolubilisation in the intestinal phase was not significantly influenced by the matrix structure (liquid or gel), but was more dependent on the calcium source, this effect leading to different final calcium bioaccessibility from 36% to 20%.

• Exploration of the molecular interactions between angiotensin-I-converting enzyme (ACE) and the inhibitory peptides derived from hazelnut (Corylus heterophylla Fisch.)
24 novembre 2017
Publication date: 15 April 2018
Source:Food Chemistry, Volume 245

Author(s): Chunlei Liu, Li Fang, Weihong Min, Jingsheng Liu, Hongmei Li

The mechanism of action of food-derived angiotensin-I-converting enzyme (ACE) inhibitory peptides has not been completely elucidated. In the present study, ion-exchange chromatography, gel filtration chromatography, reverse phase-high performance liquid chromatography, and liquid chromatography-electrospray ionization–tandem mass (LC-ESI-MS/MS) were employed for purifying and identifying the ACE inhibitory peptides from hazelnut. To understand the mode of action of these peptides, ACE inhibition kinetics, in vitro and in vivo bioavailability assays, active site analysis, and interaction between the inhibitory peptides and ACE were investigated. The results identified novel ACE inhibitory peptides Ala-Val-Lys-Val-Leu (AVKVL), Tyr-Leu-Val-Arg (YLVR), and Thr-Leu-Val-Gly-Arg (TLVGR) with IC50 values of 73.06, 15.42, and 249.3 μM, respectively. All peptides inhibited the ACE activity via a non-competitive mode. The binding free energies of AVKVL, YLVR, and TLVGR for ACE were −3.46, −6.48, and −7.37 kcal/mol, respectively. The strong inhibition of ACE by YLVR may be attributed to the formation of cation–pi interactions.

• Freeze-dried phosphatidylcholine liposomes encapsulating various antioxidant extracts from natural waste as functional ingredients in surimi gels
24 novembre 2017
Publication date: 15 April 2018
Source:Food Chemistry, Volume 245

Author(s): D. Marín, A. Alemán, A. Sánchez-Faure, P. Montero, M.C. Gómez-Guillén

Three antioxidant extracts (collagen hydrolysate, pomegranate peel extract, shrimp lipid extract) were encapsulated in soy phosphatidylcholine liposomes with the addition of glycerol. The particle size of the fresh liposomes ranged from 75.7 to 81.0 nm and zeta potential from -64.6 to −88.2 mV. Freeze-drying increased particle size (199–283 nm), and slightly decreased zeta potential. The lyophilized liposomes were incorporated in squid surimi gels at 10.5% concentration. An alternative functional formulation was also prepared by adding 2% of non-encapsulated bioactive extract. The gels were characterized in terms of colour, texture and oxidative stability (TBARS) after processing and also after frozen storage. The incorporation of the freeze-dried liposomes caused a slight decrease in gel strength and contributed to maintaining the stability of the gels during long-term frozen storage. The antioxidant properties of the bioactive extracts, liposomes and in vitro digested surimi gels were determined.

• Effects of vacuum chopping on physicochemical and gelation properties of myofibrillar proteins from silver carp (Hypophthalmichthys molitrix)
24 novembre 2017
Publication date: 15 April 2018
Source:Food Chemistry, Volume 245

Author(s): Yaolan Ma, Shanbai Xiong, Juan You, Yang Hu, Qilin Huang, Tao Yin

Physicochemical and gelation properties of myofibrillar proteins from silver carp surimi as affected by chopping under different vacuum degrees (0, 0.01, 0.02, 0.04, 0.06 and 0.08 MPa) were investigated. With the increase of vacuum degree, size and quantity of air bubbles in surimi paste decreased, disulfide bond content of myofibrillar proteins decreased significantly (p &lt; .05) and then slight increased (p &gt; .05), while surface hydrophobicity of myofibrillar proteins increased gradually (p &lt; .05). Gel mechanical properties, chemical interactions (nonspecific associations, hydrogen bond and hydrophobic interactions) and FAXL (cross-linking degree of free amino group) of heat-induced surimi gel increased significantly (p &lt; .05) with vacuum degree. Scanning electron microscopy (SEM) observation showed that three-dimensional network of surimi gel under higher vacuum degree was more compact and orderly. Results indicated that vacuum chopping imparted physicochemical and structural changes of fish myofibrillar protein, which might contribute to the improvement in gelling properties of myofibrillar proteins.

• A novel aspartic protease from Rhizomucor miehei expressed in Pichia pastoris and its application on meat tenderization and preparation of turtle peptides
24 novembre 2017
Publication date: 15 April 2018
Source:Food Chemistry, Volume 245

Author(s): Qian Sun, Fusheng Chen, Fang Geng, Yongkang Luo, Siyi Gong, Zhengqiang Jiang

A novel aspartic protease gene (RmproA) was cloned from the thermophilic fungus Rhizomucor miehei CAU432 and expressed in Pichia pastoris. The RmproA was successfully expressed in P. pastoris as an active extracellular protease. High protease activity of 3480.4 U/mL was obtained by high cell-density fermentation. The protease was purified by the two step protocols to homogeneity. The molecular mass of the RmproA was estimated to be 52.4 kDa by SDS-PAGE and 50.6 kDa by gel filtration. The purified enzyme was optimally active at pH 5.5 and 55 °C, respectively. The enzyme exhibited a broad range of substrate specificity. RmproA-treated pork muscle showed lower shear force than papain-treated sample at a relative low concentration, suggesting its effectiveness on meat tenderization. Moreover, turtle hydrolysis by RmproA resulted in a large amount of small peptides, which exhibited high ACE-inhibitory activity. Thus, RmproA may be a potential candidate for several industrial applications.

• Cross priming amplification with nucleic acid test strip analysis of mutton in meat mixtures
24 novembre 2017
Publication date: 15 April 2018
Source:Food Chemistry, Volume 245

Author(s): Tao Feng, Sufang Li, Sunan Wang, Jiarong Pan

A simple, sensitive, accurate and affordable rapid detection of meat species authentication is urgently needed in food industry. In this study, a cross priming amplification (CPA) combining nucleic acid test strip (CPA-Strip) assay for rapid detection of mutton from meat mixture were developed and its feasibility was investigated. In an isothermal CPA system, cytochrome b (cytb) gene as target was amplified at 63°C for 60min. The nucleic acid strip was able to show the corresponding test line in the presence of target gens in 5min. Non-targeting gene interference was not evident. The CPA-Strip has been applied for the detection of 0.1–100% mutton in a thermal treated meat mixtures with a detection limit of a detect limit of 1%. CPA-Strip assay would be a promising simple, rapid and sensitive method for identification of target species in raw and processed meat mixtures.

• Evidence from SINPHONIE project: Impact of home environmental exposures on respiratory health among school-age children in Romania
24 novembre 2017
Publication date: 15 April 2018
Source:Science of The Total Environment, Volume 621

Author(s): Yi Lu, Shao Lin, Wayne R. Lawrence, Ziqiang Lin, Eugen Gurzau, Eva Csobod, Iulia A. Neamtiu

Background Exposure to indoor air pollutants at home was found to be associated with respiratory diseases. As lifestyle changes with rapid economic growth in Romania, the aim of our study is to describe the characteristics of Romanian homes and their impact on children's respiratory health. Methods Self-reported information on respiratory symptoms was collected from 280 Romanian elementary school students in 2011, and the symptoms were categorized into allergy, asthma-like, and flu-like symptoms. Home characteristics and demographic information were collected from questionnaires answered by parents. The association between home characteristics and respiratory health was assessed through multivariate logistic regression controlling for school indoor exposure. Results As compared to U.S. households, Romanian homes have a higher percentage of smokers, limited use of indoor climate control, and higher use of iron stoves. Exposure to environmental tobacco smoke was associated with both asthma and allergy symptoms. Additional risk factors identified for allergy symptoms include living in apartments, near pesticide sprayed areas, and the use of incense sticks. The significantly higher risk of flu-like symptoms was associated with mold and dampness issues, the use of air conditioner, gas heater/iron stove in children's bedroom. Conclusion Our findings suggest that an increase in respiratory symptoms among Romanian school-age children can be partly related to their environmental exposure at home. Since most of the identified risk factors are preventable, our results provide critical information and evidence for policymakers, to develop target intervention and education strategies.

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• Biphenotypic sinonasal sarcoma: A series of six cases with evaluation of role of β-catenin immunohistochemistry in differential diagnosis
24 novembre 2017
Publication date: April 2018
Source:Annals of Diagnostic Pathology, Volume 33

Author(s): Aanchal Kakkar, Madhu Rajeshwari, Pirabu Sakthivel, Mehar C. Sharma, Suresh C. Sharma

Introduction Biphenotypic sinonasal sarcoma (BSNS) is a recently described mesenchymal tumor exclusive to the sinonasal region. It is a low grade sarcoma, displaying evidence of myogenic and neural differentiation. Role of β-catenin immunohistochemistry in distinguishing it from its morphological mimics is not well-established. We conducted this study to identify cases of BSNS from our archives, and to examine immunopositivity for β-catenin in them as well as in its close differential diagnosis. Methods All cases of nasal cavity and paranasal sinus mesenchymal neoplasms were identified. Histopathological features were reviewed. Cases showing smooth muscle actin (SMA) and S-100 immunopositivity, and typical morphology were reclassified as BSNS. β-catenin immunoexpression was assessed. Results Twenty-one mesenchymal tumors, including 12 sinonasal hemangiopericytoma (SNHPC), five solitary fibrous tumors (SFT), three BSNS, and one synovial sarcoma were identified. Three SNHPC cases were reclassified as BSNS. BSNS patients included one male and five females, with mean age of 51years. Five BSNS cases (83.3%) showed nuclear β-catenin immunopositivity. SNHPC cases also were β-catenin positive (60%). Conclusion BSNS is a rare sinonasal neoplasm, frequently misdiagnosed as SNHPC and SFT. β-catenin immunopositivity is seen in majority of cases, indicating a role in pathogenesis. However, due to positivity in other tumors like SNHPC, it has limited role in differential diagnosis.

• Extended Fitts’ model of pointing time in eye-gaze input system - Incorporating effects of target shape and movement direction into modeling
24 novembre 2017
Publication date: April 2018
Source:Applied Ergonomics, Volume 68

Author(s): Atsuo Murata, Daichi Fukunaga

This study attempted to investigate the effects of the target shape and the movement direction on the pointing time using an eye-gaze input system and extend Fitts' model so that these factors are incorporated into the model and the predictive power of Fitts' model is enhanced. The target shape, the target size, the movement distance, and the direction of target presentation were set as within-subject experimental variables. The target shape included: a circle, and rectangles with an aspect ratio of 1:1, 1:2, 1:3, and 1:4. The movement direction included eight directions: upper, lower, left, right, upper left, upper right, lower left, and lower right. On the basis of the data for identifying the effects of the target shape and the movement direction on the pointing time, an attempt was made to develop a generalized and extended Fitts’ model that took into account the movement direction and the target shape. As a result, the generalized and extended model was found to fit better to the experimental data, and be more effective for predicting the pointing time for a variety of human-computer interaction (HCI) task using an eye-gaze input system.

• The effect of a multi-axis suspension on whole body vibration exposures and physical stress in the neck and low back in agricultural tractor applications
24 novembre 2017
Publication date: April 2018
Source:Applied Ergonomics, Volume 68

Author(s): Jeong Ho Kim, Jack T. Dennerlein, Peter W. Johnson

Whole body vibration (WBV) exposures are often predominant in the fore-aft (x) or lateral (y) axis among off-road agricultural vehicles. However, as the current industry standard seats are designed to reduce mainly vertical (z) axis WBV exposures, they may be less effective in reducing drivers' exposure to multi-axial WBV. Therefore, this laboratory-based study aimed to determine the differences between a single-axial (vertical) and multi-axial (vertical + lateral) suspension seat in reducing WBV exposures, head acceleration, self-reported discomfort, and muscle activity (electromyography) of the major muscle of the low back, neck and shoulders. The results showed that the multi-axial suspension seat had significantly lower WBV exposures compared to the single-axial suspension seats (p' &lt; 0.04). Similarly, the multi-axial suspension seat had lower head acceleration and muscle activity of the neck, shoulder, and low back compared to the single-axial suspension seat; some but not all of the differences were statistically significant. These results indicate that the multi-axial suspension seat may reduce the lateral WBV exposures and associated muscular loading in the neck and low back in agricultural vehicle operators.

• Biomechanical evaluation of exoskeleton use on loading of the lumbar spine
24 novembre 2017
Publication date: April 2018
Source:Applied Ergonomics, Volume 68

Author(s): Eric B. Weston, Mina Alizadeh, Gregory G. Knapik, Xueke Wang, William S. Marras

The objective of this study was to investigate biomechanical loading to the low back as a result of wearing an exoskeletal intervention designed to assist in occupational work. Twelve subjects simulated the use of two powered hand tools with and without the use of a Steadicam vest with an articulation tool support arm in a laboratory environment. Dependent measures of peak and mean muscle forces in ten trunk muscles and peak and mean spinal loads were examined utilizing a dynamic electromyography-assisted spine model. The exoskeletal device increased both peak and mean muscle forces in the torso extensor muscles (p &lt; 0.001). Peak and mean compressive spinal loads were also increased up to 52.5% and 56.8%, respectively, for the exoskeleton condition relative to the control condition (p &lt; 0.001). The results of this study highlight the need to design exoskeletal interventions while anticipating how mechanical loads might be shifted or transferred with their use.

• Objective assessment of knife sharpness over a working day cutting meat
24 novembre 2017
Publication date: April 2018
Source:Applied Ergonomics, Volume 68

Author(s): Adriana Savescu, Aude Cuny-Guerrier, Pascal Wild, Gilles Reno, Agnès Aublet-Cuvelier, Laurent Claudon

Knife sharpness is one of multiple factors involved in musculoskeletal disorders in industrial meat cutting. The aim of this study was to objectively evaluate, in real working situations, how knife sharpness changed over a working day cutting meat, and to analyse the impact of sharpening, steeling and meat-cutting activities on these variations. Twenty-two meat-cutting workers from three different companies participated in the study. The methods included measurements of knife sharpness in relation to real work situations and consideration of the way meat-cutting and sharpening operations were organised. Results showed that the type of meat-cutting activities, the steeling strategy adopted by the worker, including the types of tool used, and the overall organisation of the sharpening task all had a significant influence on how knife sharpness evolved over a 2-h period and over an entire working day. To improve MSD prevention, sharpening and steeling operations should not be considered as independent activities, but taken into account as a continuity of working actions. Appropriate assessment of knife sharpness by meat cutters affects how they organise meat-cutting and sharpening tasks.

• Assessment of an active industrial exoskeleton to aid dynamic lifting and lowering manual handling tasks
24 novembre 2017
Publication date: April 2018
Source:Applied Ergonomics, Volume 68

Author(s): Kirsten Huysamen, Michiel de Looze, Tim Bosch, Jesus Ortiz, Stefano Toxiri, Leonard W. O'Sullivan

The aim of this study was to evaluate the effect of an industrial exoskeleton on muscle activity, perceived musculoskeletal effort, measured and perceived contact pressure at the trunk, thighs and shoulders, and subjective usability for simple sagittal plane lifting and lowering conditions. Twelve male participants lifted and lowered a box of 7.5 kg and 15 kg, respectively, from mid-shin height to waist height, five times, both with and without the exoskeleton. The device significantly reduced muscle activity of the Erector Spinae (12%-15%) and Biceps Femoris (5%). Ratings of perceived musculoskeletal effort in the trunk region were significantly less with the device (9.5%-11.4%). The measured contact pressure was highest on the trunk (91.7 kPa-93.8 kPa) and least on shoulders (47.6 kPa-51.7 kPa), whereas pressure was perceived highest on the thighs (35-44% of Max LPP). Six of the users rated the device usability as acceptable. The exoskeleton reduced musculoskeletal loading on the lower back and assisted with hip extensor torque during lifting and lowering. Contact pressures fell below the Pain Pressure Threshold. Perceived pressure was not exceptionally high, but sufficiently high to cause discomfort if used for long durations.

• Taxonomy and stratigraphy of Early Cretaceous species of Debrunia Masse and Fenerci-Masse (Hippuritida, Monopleuridae) of the Mediterranean region
24 novembre 2017
Publication date: April 2018
Source:Cretaceous Research, Volume 84

Author(s): Jean-Pierre Masse, Mukerrem Fenerci-Masse

The genus Debrunia is characterized by its myophoral organisation: the left valve posterior myophore is an erect plate, the anterior is a bulge or a crest, myophores of right valve are on shell wall, the ligament groove is inconspicuous and the cardinal apparatus tends to be shifted posteriorly. Shell habit varies from low conical to elongated cylindrical, and the shape of the left valve ranges from capuloid to flat. The taxonomic revision of Debrunia species of the Mediterranean regions reveals the presence of thirteen species, among which seven are described as new. Multiple Component Analysis and Cluster Analysis document the existence of five groups of species in correspondence with the height of the left valve and the commissural diameter. The longevity of Debrunia is high, 32 Myr, whereas its species have shorter durations which account for a significant biostratigraphic potential within the Valanginian–Albian time span. Debrunia has its FO (First occurrence) in the lower Valanginian and its LO (Last occurrence) in the Albian. Its developmental phase starts in the Hauterivian, marked by an increasing species diversity and a biogeographic expansion; and peaks in the late Barremian, followed by a collapse in diversity and a specific turnover, coeval with the “Agriopleura extinction event”. The mid-Aptian crisis is expressed by a drastic decline in species diversity, controlled by the overall restriction or demise of carbonate platforms in European regions. As elevators, Debrunia species tend to build dense monospecific aggregations and some of them possess a remarkable bioconstructional potential. The contribution of Debrunia to rudist communities is significant throughout the history of the genus.

• Individual differences in sensorimotor skills among musicians
24 novembre 2017
Publication date: April 2018
Source:Current Opinion in Behavioral Sciences, Volume 20

Author(s): Shinichi Furuya

The grace of a musician has always fascinated people in the world. It has been widely accepted that quantity of musical practice is a prerequisite but not sufficient for acquisition of musical expertise. An increasing number of studies have recently proposed that an interaction between gene and environment underlies musical expertise, based on empirical evidences demonstrating roles of genetic predisposition. In contrast, it has not been elucidated how ways of musical practice play a role in the expertise, which limits optimizing musical training and education that realizes expressive and virtuosic performance. The present article proposes a theoretical framework for possible impacts of how to practice on acquisition of fast, accurate, and efficient musical performance, on the basis of principles and empirical evidences of motor learning.

• Neural mechanisms of movement planning: motor cortex and beyond
24 novembre 2017
Publication date: April 2018
Source:Current Opinion in Neurobiology, Volume 49

Author(s): Karel Svoboda, Nuo Li

Neurons in motor cortex and connected brain regions fire in anticipation of specific movements, long before movement occurs. This neural activity reflects internal processes by which the brain plans and executes volitional movements. The study of motor planning offers an opportunity to understand how the structure and dynamics of neural circuits support persistent internal states and how these states influence behavior. Recent advances in large-scale neural recordings are beginning to decipher the relationship of the dynamics of populations of neurons during motor planning and movements. New behavioral tasks in rodents, together with quantified perturbations, link dynamics in specific nodes of neural circuits to behavior. These studies reveal a neural network distributed across multiple brain regions that collectively supports motor planning. We review recent advances and highlight areas where further work is needed to achieve a deeper understanding of the mechanisms underlying motor planning and related cognitive processes.

• Anti-inflammatory agents in peripheral arterial disease
24 novembre 2017
Publication date: April 2018
Source:Current Opinion in Pharmacology, Volume 39

Author(s): Alexios S Antonopoulos, Evi Papanikolaou, Georgia Vogiatzi, Evangelos Oikonomou, Dimitris Tousoulis

Inflammation is pivotally involved in coronary and peripheral atherosclerotic disease. This established concept is based on both experimental animal models of vascular inflammation and Mendelian randomization studies demonstrating a causal relationship between pro-inflammatory cytokines (e.g. interleukin-6) and cardiovascular disease risk. More recently, the reduction of cardiovascular events by use of an interleukin-1β inhibitor (canakinumab) has revived interest in the use of anti-inflammatory agents for the treatment of atherosclerotic disease, including peripheral arterial disease. In this mini review article we provide an update on the pleiotropic anti-inflammatory properties of approved drugs for use in cardiovascular disease (e.g. antiplatelets, statins, PCSK9 inhibitors) and discuss the role of targeted or untargeted anti-inflammatory atheroprotection in peripheral arterial disease by agents such as colchicine, methotrexate, anti-TNF-α agents and monoclonal antibodies against interleukin-signaling.

• Unc93b1 is essential for cytokine activation of five PAMPs in the orange-spotted grouper (Epinephelus coioides)
24 novembre 2017
Publication date: April 2018
Source:Developmental &amp; Comparative Immunology, Volume 81

Author(s): Yaosi Liang, Yu Wang, Liangge He, Jianan He, Wan Peng, Libin Zhou, Yong Zhang, Haifa Zhang, Herong Shi, Haoran Lin, Danqi Lu

Toll-like receptors (TLRs) are important innate immune receptors that recognize multiple pathogen-associated molecular patterns (PAMPs) and activate the immune responses to resist the invasion of pathogens. Many TLRs need assistance from trafficking chaperones to transport to the specific cell compartments and then are processed before they are activated. In this study, we identified an important trafficking chaperone, Unc-93 homolog B1 (unc93b1), from the Epinephelus coioides (orange-spotted grouper). The deduced protein sequence of Eco.unc93b1 was 632 amino acids, containing 12 transmembrane domains, consistent with other UNC93B1 proteins from other species. Phylogenetic analysis showed that Eco.Unc93b1 was clustered with teleost Unc93b1 and had the closest relationship with Larimichthys crocea (large yellow croaker) Unc93b1. Eco.unc93b1 was expressed the highest in the spleen, and its protein was co-localized with the endoplasmic reticulum and early endosomes in both human embryonic kidney 293T cells and grouper spleen cells (GS cells). Moreover, the stimulation of lipopolysaccharide (LPS), high-molecular-weight poly (I:C) (HMW), imidazoquinoline (R848), polyadenylic-polyuridylic acid (poly AU), and 19-mer Staphylococcus aureus 23S rRNA-derived oligoribonucleotide (ORN Sa 19) promoted the mRNA expression of unc93b1 in GS cells with different patterns. Furthermore, the cytokine expression induced by these PAMPs was suppressed, while Eco.unc93b1 was knocked down, by small interfering RNA. In conclusion, these results suggest that Eco.unc93b1 plays an essential role in several PAMP-induced immune responses.

• Cellular and biochemical parameters following autotomy and ablation-mediated cheliped loss in the Chinese mitten crab, Eriocheir sinensis
24 novembre 2017
Publication date: April 2018
Source:Developmental &amp; Comparative Immunology, Volume 81

Author(s): Xiao-zhen Yang, Cong Zhang, Gen-yong Huang, Min-jie Xu, Yong-xu Cheng, Zhi-gang Yang, Qian Zhang, Yi-yue Wang

In the pond culture of juvenile Eriocheir sinensis, various factors have frequently led to a high rate of autotomy and limb impairments. This study evaluated the differential effects of cheliped loss with autotomy and ablation on the short-term cellular and biochemical parameters of juvenile E. sinensis. In this study, compared with the crabs before treatment, the total hemocyte counts (THC), granulocyte counts (GC), hemocyte agglutination, phosphatase activity and glucose metabolism levels were significantly increased, while hyalinocyte counts (HC) and total antioxidant capacity (T-AOC) were significantly decreased within 3 h. However, the THC levels, hemocyte agglutination and hemocyte proliferation were significantly higher in the ablation group within 3 h compared to the autotomy group. Moreover, the changes of glucose metabolism and immune-related enzymes activities in ablation groups were later than autotomy groups. The bacterial challenge showed that the mortality rate of the ablation group was significantly higher than that of the autotomy group. Therefore, the observations in this study indicate that compared with the passive trauma response of ablation, autotomy is a congenital, efficient, and active trauma response mechanism, which is of great significance to the survival and growth of E. sinensis.

• Identification and characterization of a calcium-dependent lily-type lectin from black rockfish (Sebastes schlegelii): Molecular antennas are involved in host defense via pathogen recognition
24 novembre 2017
Publication date: April 2018
Source:Developmental &amp; Comparative Immunology, Volume 81

Author(s): Roopasingam Kugapreethan, Qiang Wan, Jehanathan Nilojan, Jehee Lee

Lily-type lectins (LTLs) are soluble pathogen recognition receptors (PRRs) that contain one or more characteristic carbohydrate recognition domains (CRDs), through which LTLs bind reversibly and specifically to cognate sugar moieties present on the invading pathogen membrane and trigger the host innate immune responses. In this study, we identified a LTL homolog (SsLTL) from black rockfish (Sebastes schlegelii) transcriptome database and its functional roles in innate immunity was investigated in vitro and in vivo. Three mannose-binding sites were found in the protein sequence of SsLTL, among which two sites are conserved with those in mannose-binding lectins of monocotyledonous plants. SsLTL were highly expressed in both the external and internal mucosal tissues of healthy rockfish. During the immune challenge, early up-regulation of SsLTL mRNA expression showed in gill and blood upon both poly I:C and S. iniae challenges. In contrast, the challenge with lipopolysaccharide significantly down-regulated SsLTL expression in both examined tissues. Recombinant SsLTL showed a hemagglutination activity toward fish erythrocytes, which could be enhanced by the addition of calcium ions. Furthermore, strong agglutination activity of SsLTL was also observed with a broad range of fish pathogenic bacteria. Our results implied the crucial role of SsLTL as a PRR molecule in the black rockfish defense mechanism against invading microbial pathogens.

• Rainbow trout (Oncorhynchus mykiss) adipose tissue undergoes major changes in immune gene expression following bacterial infection or stimulation with pro-inflammatory molecules
24 novembre 2017
Publication date: April 2018
Source:Developmental &amp; Comparative Immunology, Volume 81

Author(s): Kimberly A. Veenstra, Eakapol Wangkahart, Tiehui Wang, Lincoln Tubbs, Juliette Ben Arous, Christopher J. Secombes

In mammals, visceral adipose is increasingly seen as playing an important role in immune function with numerous pro-inflammatory, anti-inflammatory and immune-modulating proteins and peptides being identified in adipocytes. Adipose is also now known as a tissue that has an important role in the regulation of peritoneal immune responses. Despite this, only lately has consideration been given to visceral adipose as an important immune tissue in fish, especially in the context of intraperitoneal vaccination. The present study demonstrates that fish visceral adipose is capable of expressing a large range of immune molecules in response to stimulation with a live bacterium (A. salmonicida), a bacterial PAMP (Y. ruckeri flagellin), and the pro-inflammatory cytokines IL-1β, TNF-α3 and IFN-γ. Following infection and stimulation with flagellin and IL-1β a large upregulation of pro-inflammatory and antimicrobial molecules was seen, with a high degree of overlap. TNF-α treatment affected relatively few genes and the effects were more modest. IFN-γ had the smallest impact on adipose but IFN-γ inducible genes showed some of the largest effects. Overall, it is clear that adipose tissue should be considered an active immune site in fish, capable of participating in and influencing immune responses.

• Design and evaluation of a smart insole: Application for continuous monitoring of frail people at home
24 novembre 2017
Publication date: 1 April 2018
Source:Expert Systems with Applications, Volume 95

Author(s): Yoann Charlon, Eric Campo, Damien Brulin

The objectives of this work are to develop a technological solution designed to support active aging of frail older individuals and to conduct a first evaluation of the devices. We wish to bring a reflection in the field of connected health by setting up a remote medical follow-up. In this context, the connected object presented in this article aims at implementation a longitudinal follow-up of the walk by a health professional. Continuous remote data analysis applies behavior learning methods by modeling walking habits and allows the detection of deviations by application of thresholds defined by the expert. We propose an instrumented shoe insole to provide such monitoring (number of steps, distance covered and gait speed). In this perspective, we designed a low power microelectronic device integrated into the thickness of an insole in order to demonstrate the technical feasibility of such a device in laboratory and in living conditions. The project called “FOOT-TEST” is funded by the DIRECCTE of the Midi-Pyrenees Region in France. This project brought together a manufacturer who specializes in the design of foot-care systems, geriatricians and our laboratory specialized in electronics to propose a technical solution adapted to frail individuals. Two smart insole prototypes have been produced and a first evaluation of the smart insole in real use conditions has been performed. According to user feedback, the smart insole seems to be much easier to use than commercial connected pedometers. Moreover, in terms of performance, the smart insole provides better results. In this paper, we present specifications of the device, technological choices and the design of two versions of the smart insole, methods used to measure desired settings, a first evaluation of the system and, finally, preliminary conclusions and work in progress.

• Intramuscular variations of proteome and muscle fiber type distribution in semimembranosus and semitendinosus muscles associated with pork quality
24 novembre 2017
Publication date: 1 April 2018
Source:Food Chemistry, Volume 244

Author(s): Gap-Don Kim, Han-Sul Yang, Jin-Yeon Jeong

Proteome analysis was performed to understand intramuscular variations in muscle fiber distribution in semimembranosus (SM) and semitendinosus (ST) muscles associated with pork quality. Fifteen SM and ST muscles were separated into dark and light portions. The relative area of oxidative fiber was higher (P &lt; .0001) in dark portion than that in light portion, while glycolytic fiber types were distributed primarily (P &lt; .01) in light portions regardless of muscle types. Myosin-1, myosin-4, troponin complex (fast), myosin light chains, and metabolic enzymes responsible for fast-twitch glycolytic types were overexpressed in light portions (P &lt; .05). However, myosin-2, myosin-7, myoglobin, and mitochondrial oxidative metabolic enzymes were closely related to slow-twitch oxidative fibers. These resulted in high pH, redness, and tenderness but low lightness and drip loss of pork quality. In conclusion, differentially expressed muscle proteins are associated with fiber type (oxidative vs. glycolytic) distribution, resulting in intramuscular variations of pork quality.

• Rapid classification of intact chicken breast fillets by predicting principal component score of quality traits with visible/near-Infrared spectroscopy
24 novembre 2017
Publication date: 1 April 2018
Source:Food Chemistry, Volume 244

Author(s): Yi Yang, Hong Zhuang, Seung-Chul Yoon, Wei Wang, Hongzhe Jiang, Beibei Jia

In this study visible/near-infrared spectroscopy (Vis/NIRS) was evaluated to rapidly classify intact chicken breast fillets. Five principal components (PC) were extracted from reference quality traits (L, pH, drip loss, expressible fluid, and salt-induced water gain). A quality grades classification method by PC1 score was proposed. With this method, 150 chicken fillets were properly classified into three quality grades, i.e., DFD (dark, firm and dry), normal, and PSE (pale, soft and exudative). Furthermore, PC1 score could be predicted using partial least squares regression (PLSR) model based on Vis/NIRS (R2p = 0.78, RPD = 1.9), without the measurement of any quality traits. Thresholds of PC1 classification method were applied to classify the predicted PC1 score values of each fillet into three quality grades. The classification accuracy of calibration and prediction set were 85% and 80%, respectively. Results revealed that PC1 score classification method is feasible, and with Vis/NIRS, this method could be rapidly implemented.

• Comparative proteomic profiling of myofibrillar proteins in dry-cured ham with different proteolysis indices and adhesiveness
24 novembre 2017
Publication date: 1 April 2018
Source:Food Chemistry, Volume 244

Author(s): M. López-Pedrouso, C. Pérez-Santaescolástica, D. Franco, E. Fulladosa, J. Carballo, C. Zapata, J.M. Lorenzo

Excessive proteolysis during dry-cured ham processing may lead to high adhesiveness and consumer dissatisfaction. The aim of this research is to identify biomarkers for proteolysis and adhesiveness. Two hundred biceps femoris porcine muscle samples from Spanish dry-cured ham were firstly evaluated for various physicochemical parameters, including their proteolysis indices and instrumental adhesiveness. Proteins of samples with extreme proteolysis indices were separated by two-dimensional electrophoresis and identified by tandem mass spectrometry (MALDI-TOF/TOF). We found that hams of higher proteolysis index had statistically significant increased adhesiveness. Proteomic analysis revealed statistically significant qualitative and quantitative differences between sample groups. Thus, protein fragments increased remarkably in samples with higher proteolysis index scores. In addition, higher proteolysis index hams showed increased degradation for a total of five non-redundant myofibrillar and sarcoplasmic proteins. However, myosin-1, α-actin and myosin-4 proteins were the biomarkers that underwent the most intense response to proteolysis and adhesiveness.

• Micro-emulsification/encapsulation of krill oil by complex coacervation with krill protein isolated using isoelectric solubilization/precipitation
24 novembre 2017
Publication date: 1 April 2018
Source:Food Chemistry, Volume 244

Author(s): Liu Shi, Sarah K. Beamer, Hong Yang, Jacek Jaczynski

This study determined feasibility of krill protein isolated with isoelectric solubilization/precipitation (ISP) as wall material to microencapsulate krill oil by freeze-drying. Effects of krill oil/krill protein ratio on properties of microcapsules were investigated. With increased ratio, crude protein of microcapsules decreased, while total lipid increased. Although microcapsule oil loading capacity increased, loading and encapsulation efficiencies decreased. Thin layer chromatography (TLC) confirmed abundance of phospholipids, which are amphiphilic; and thus, resulted in stable emulsion (emulsion stability index). Microcapsules contained ω-3 polyunsaturated fatty acids (PUFAs) at 43–60, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) at 28–41 and 9–11 g/100g of total FAs, respectively. SDS-PAGE electrophoresis revealed proteolysis of ISP krill protein, probably causing reduced loading and encapsulation efficiencies. SEM showed that krill oil/krill protein ratio affected surface microstructure. ISP krill protein showed potential as a wall material to microencapsulate krill oil; and thus, expand application of krill oil/protein for human consumption.

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• Dynamic classifier selection: Recent advances and perspectives
24 novembre 2017
Publication date: May 2018
Source:Information Fusion, Volume 41

Author(s): Rafael M.O. Cruz, Robert Sabourin, George D.C. Cavalcanti

Multiple Classifier Systems (MCS) have been widely studied as an alternative for increasing accuracy in pattern recognition. One of the most promising MCS approaches is Dynamic Selection (DS), in which the base classifiers are selected on the fly, according to each new sample to be classified. This paper provides a review of the DS techniques proposed in the literature from a theoretical and empirical point of view. We propose an updated taxonomy based on the main characteristics found in a dynamic selection system: (1) The methodology used to define a local region for the estimation of the local competence of the base classifiers; (2) The source of information used to estimate the level of competence of the base classifiers, such as local accuracy, oracle, ranking and probabilistic models, and (3) The selection approach, which determines whether a single or an ensemble of classifiers is selected. We categorize the main dynamic selection techniques in the DS literature based on the proposed taxonomy. We also conduct an extensive experimental analysis, considering a total of 18 state-of-the-art dynamic selection techniques, as well as static ensemble combination and single classification models. To date, this is the first analysis comparing all the key DS techniques under the same experimental protocol. Furthermore, we also present several perspectives and open research questions that can be used as a guide for future works in this domain.

• Extended Fitts’ model of pointing time in eye-gaze input system - Incorporating effects of target shape and movement direction into modeling
24 novembre 2017
Publication date: April 2018
Source:Applied Ergonomics, Volume 68

Author(s): Atsuo Murata, Daichi Fukunaga

This study attempted to investigate the effects of the target shape and the movement direction on the pointing time using an eye-gaze input system and extend Fitts' model so that these factors are incorporated into the model and the predictive power of Fitts' model is enhanced. The target shape, the target size, the movement distance, and the direction of target presentation were set as within-subject experimental variables. The target shape included: a circle, and rectangles with an aspect ratio of 1:1, 1:2, 1:3, and 1:4. The movement direction included eight directions: upper, lower, left, right, upper left, upper right, lower left, and lower right. On the basis of the data for identifying the effects of the target shape and the movement direction on the pointing time, an attempt was made to develop a generalized and extended Fitts’ model that took into account the movement direction and the target shape. As a result, the generalized and extended model was found to fit better to the experimental data, and be more effective for predicting the pointing time for a variety of human-computer interaction (HCI) task using an eye-gaze input system.

• The effect of a multi-axis suspension on whole body vibration exposures and physical stress in the neck and low back in agricultural tractor applications
24 novembre 2017
Publication date: April 2018
Source:Applied Ergonomics, Volume 68

Author(s): Jeong Ho Kim, Jack T. Dennerlein, Peter W. Johnson

Whole body vibration (WBV) exposures are often predominant in the fore-aft (x) or lateral (y) axis among off-road agricultural vehicles. However, as the current industry standard seats are designed to reduce mainly vertical (z) axis WBV exposures, they may be less effective in reducing drivers' exposure to multi-axial WBV. Therefore, this laboratory-based study aimed to determine the differences between a single-axial (vertical) and multi-axial (vertical + lateral) suspension seat in reducing WBV exposures, head acceleration, self-reported discomfort, and muscle activity (electromyography) of the major muscle of the low back, neck and shoulders. The results showed that the multi-axial suspension seat had significantly lower WBV exposures compared to the single-axial suspension seats (p' &lt; 0.04). Similarly, the multi-axial suspension seat had lower head acceleration and muscle activity of the neck, shoulder, and low back compared to the single-axial suspension seat; some but not all of the differences were statistically significant. These results indicate that the multi-axial suspension seat may reduce the lateral WBV exposures and associated muscular loading in the neck and low back in agricultural vehicle operators.

• Biomechanical evaluation of exoskeleton use on loading of the lumbar spine
24 novembre 2017
Publication date: April 2018
Source:Applied Ergonomics, Volume 68

Author(s): Eric B. Weston, Mina Alizadeh, Gregory G. Knapik, Xueke Wang, William S. Marras

The objective of this study was to investigate biomechanical loading to the low back as a result of wearing an exoskeletal intervention designed to assist in occupational work. Twelve subjects simulated the use of two powered hand tools with and without the use of a Steadicam vest with an articulation tool support arm in a laboratory environment. Dependent measures of peak and mean muscle forces in ten trunk muscles and peak and mean spinal loads were examined utilizing a dynamic electromyography-assisted spine model. The exoskeletal device increased both peak and mean muscle forces in the torso extensor muscles (p &lt; 0.001). Peak and mean compressive spinal loads were also increased up to 52.5% and 56.8%, respectively, for the exoskeleton condition relative to the control condition (p &lt; 0.001). The results of this study highlight the need to design exoskeletal interventions while anticipating how mechanical loads might be shifted or transferred with their use.

• Assessment of an active industrial exoskeleton to aid dynamic lifting and lowering manual handling tasks
24 novembre 2017
Publication date: April 2018
Source:Applied Ergonomics, Volume 68

Author(s): Kirsten Huysamen, Michiel de Looze, Tim Bosch, Jesus Ortiz, Stefano Toxiri, Leonard W. O'Sullivan

The aim of this study was to evaluate the effect of an industrial exoskeleton on muscle activity, perceived musculoskeletal effort, measured and perceived contact pressure at the trunk, thighs and shoulders, and subjective usability for simple sagittal plane lifting and lowering conditions. Twelve male participants lifted and lowered a box of 7.5 kg and 15 kg, respectively, from mid-shin height to waist height, five times, both with and without the exoskeleton. The device significantly reduced muscle activity of the Erector Spinae (12%-15%) and Biceps Femoris (5%). Ratings of perceived musculoskeletal effort in the trunk region were significantly less with the device (9.5%-11.4%). The measured contact pressure was highest on the trunk (91.7 kPa-93.8 kPa) and least on shoulders (47.6 kPa-51.7 kPa), whereas pressure was perceived highest on the thighs (35-44% of Max LPP). Six of the users rated the device usability as acceptable. The exoskeleton reduced musculoskeletal loading on the lower back and assisted with hip extensor torque during lifting and lowering. Contact pressures fell below the Pain Pressure Threshold. Perceived pressure was not exceptionally high, but sufficiently high to cause discomfort if used for long durations.

• The effect of bismuth on the structure, magnetic and electric properties of Co2MnO4 spinel multiferroic
24 novembre 2017
Publication date: 1 April 2018
Source:Journal of Magnetism and Magnetic Materials, Volume 451

Author(s): H. Chouaya, M. Smari, I. Walha, E. Dhahri, M.P.F. Graça, M.A. Valente

Mixed Co2Mn1−xBixO4 (x = 0, x = 0.05 and x = 0.1) samples were prepared by the sol–gel method using the citric acid route and characterized by various techniques. The X-ray diffraction (XRD) and Raman spectroscopic analyses confirmed the formation of inverse spinel cubic structure with $Fd 3 ‾ m$ space group. The introduction of Bismuth (Bi) into Co2MnO4 did not modify the ferrimagnetic character of the parent compound Co2MnO4, whereas the field-cooled magnetizations MFC and the Curie temperature Tc decreased when increasing the Bi content. The electrical properties showed an activation energy (Ea) increase caused by the decrease of the double-exchange interaction following the substitution of Mn3+ by Bi3+. Eventually, the temperature coefficient of resistance (TCR) shows significant values for all samples can be investigated also as good candidates for bolometer applications.

• High-performance miniature CSTR for biphasic C–C bond-forming reactions
24 novembre 2017
Publication date: 1 March 2018
Source:Chemical Engineering Journal, Volume 335

Author(s): Yiming Mo, Hongkun Lin, Klavs F. Jensen

Chemical transformations used in fine chemical manufacturing often involve two-phase interaction for which mass transfer limitations can lead to prolonged reaction time and reduced productivity. We present a high-performance miniature continuous stirred-tank reactor (CSTR), with non-contact magnetic coupling providing intensive agitation inside the sealed miniaturized chamber. High-speed imaging of the biphasic hydrodynamics gives an estimated mass transfer coefficient (kLa) on the order of 10 s−1, comparable to commercial passive mixing flow reactors. Case studies with two important biphasic C–C bond-forming reactions: (i) asymmetric alkylation catalyzed by cinchonidine-derived phase-transfer catalyst, and (ii) biphasic Suzuki-Miyaura C–C coupling reactions, demonstrate the versatility of the CSTR unit. Moreover, a detailed kinetic model proposed for phase-transfer reaction systems controlled by the Makosza interfacial mechanism further cross-validates the mass transfer coefficient estimates.

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• A robust structure identification method for evolving fuzzy system
24 novembre 2017
Publication date: 1 March 2018
Source:Expert Systems with Applications, Volume 93

Author(s): Hisham Haider Yusef Sa'ad, Nor Ashidi Mat Isa, Md. Manjur Ahmed, Adnan Haider Yusef Sa'd

This paper proposes a robust structure identification method (RSIM) based on incremental partitioning learning. RSIM starts with an open region (initial domain) that covers all input samples. The initial region starts with one fuzzy rule without fuzzy terms and then evolves through incremental partitioning learning, which creates many subregions for system error minimization. The three major contributions of the proposed RSIM are as follows: It locates sufficient splitting points provided through a robust partitioning technique, determines the optimum trade-off between accuracy and complexity through a novel partition-selection technique, minimizes global error through global least square optimization. These contributions offer many remarkable advantages. First, RSIM provides a solution for the curse of dimensionality. Second, RSIM can also be applied to low-dimensional problems. Third, RSIM seeks to produce few rules with low number of conditions to improve system readability. Fourth, RSIM minimizes the number of fired rules. Therefore, RSIM can achieve low-level complexity systems. Three low-dimension and six high-dimension and real-life benchmarks are used to evaluate the performance of RSIM with state-of-the art methods. Although RSIM has high interpretability, the results prove that RSIM exhibits greater accuracy than other existing methods.

• Towards unravelling the relationship between on-body, environmental and emotion data using sensor information fusion approach
24 novembre 2017
Publication date: March 2018
Source:Information Fusion, Volume 40

Author(s): Eiman Kanjo, Eman M.G. Younis, Nasser Sherkat

Over the past few years, there has been a noticeable advancement in environmental models and information fusion systems taking advantage of the recent developments in sensor and mobile technologies. However, little attention has been paid so far to quantifying the relationship between environment changes and their impact on our bodies in real-life settings. In this paper, we identify a data driven approach based on direct and continuous sensor data to assess the impact of the surrounding environment and physiological changes and emotion. We aim at investigating the potential of fusing on-body physiological signals, environmental sensory data and on-line self-report emotion measures in order to achieve the following objectives: (1) model the short term impact of the ambient environment on human body, (2) predict emotions based on-body sensors and environmental data. To achieve this, we have conducted a real-world study ‘in the wild’ with on-body and mobile sensors. Data was collected from participants walking around Nottingham city centre, in order to develop analytical and predictive models. Multiple regression, after allowing for possible confounders, showed a noticeable correlation between noise exposure and heart rate. Similarly, UV and environmental noise have been shown to have a noticeable effect on changes in ElectroDermal Activity (EDA). Air pressure demonstrated the greatest contribution towards the detected changes in body temperature and motion. Also, significant correlation was found between air pressure and heart rate. Finally, decision fusion of the classification results from different modalities is performed. To the best of our knowledge this work presents the first attempt at fusing and modelling data from environmental and physiological sources collected from sensors in a real-world setting.

• Chitosan-film associated with mesenchymal stem cells enhanced regeneration of peripheral nerves: A rat sciatic nerve model
24 novembre 2017
Publication date: March 2018
Source:Journal of Chemical Neuroanatomy, Volume 88

Author(s): Mehrnaz Moattari, Homa Mohseni Kouchesfehani, Gholamreza Kaka, Seyed Homayoon Sadraie, Majid Naghdi, Korosh Mansouri

Objective Peripheral nerve injuries comprise significant portion of the nervous system injuries. Although peripheral nerves show some capacity of regeneration after injury, but the extent of regeneration is not remarkable. Regeneration might be through the activity of the mesenchymal stem cells (MSCs) which can release growth factors or extracellular matrix components or by the therapeutic effect of some material with the MSCs. The present study aimed to evaluate the regeneration of transected sciatic nerve by a therapeutic value of mesenchymal stem cells (MSCs) associated with chitosan-film (Cs) in rat. Materials &amp; methods Male Wistar rats (n=42, 180-200g) were randomly divided into intact; control; sham; Cs; MSCs; MSCs + Cs groups. Functional recovery was evaluated at 2, 4, 6 and 8 weeks after surgery using sciatic functional index (SFI), hot water paw immersion test, electrophysiological, histological analyses. Results The rats in the MSCs+Cs group showed significant decrease in SFI and hot water paw immersion test during the 2nd to 8th weeks after surgery. Electrophysiological findings showed a significant decrease in latency time in the MSCs +Cs group. Amplitude of the nerve impulses also increased. Number of nerve fibers with more than 6 μm diameters increased significantly in MSCs+Cs. The number of nerve fibers with less than 4 μm diameters also increased significantly in MSCs+Cs group. Conclusion Taken together, mesenchymal stem cells associated with Cs could improve functional and histomorphological properties of the sciatic nerve after injury which may have some clinical outcomes as well.

• Only some patients with bulbar and spinal muscular atrophy may develop cardiac disease
24 novembre 2017
Publication date: March 2018
Source:Molecular Genetics and Metabolism Reports, Volume 14

Author(s): Josef Finsterer, Claudia Stöllberger

Objectives According to recent publications, some patients with spinal and bulbar muscular atrophy (BSMA) develop cardiac disease, manifesting as ST-segment abnormalities, Brugada-syndrome, dilative cardiomyopathy, or sudden cardiac death. Here we present neurological and cardiac data of a BSMA patient who was followed up for 10y. Case report In a male patient aged 47y, BSMA was diagnosed at age 37y upon the typical clinical presentation (postural tremor since age 12y, dysarthria since age 15y, muscle cramps since age 29y, general myalgias since age 32y, general fasciculations since age 34y, myoclonic jerks, easy fatigability, dyspnea upon exercise since age 36y) and a CAG-repeat expansion of 47±1 repeats in the androgen-receptor gene detected at age 37y. During the next 10y he additionally developed mild but slowly progressive diffuse weakness on the upper limbs and mild proximal weakness on the lower limbs. Cardiologic exam, ECG, and echocardiography were normal at ages 37y, 41y, 44y, and 47y. Conclusions Cardiac involvement may only develop in some BSMA patients within 10y, whereas neurologic abnormalities slowly progress within 10y of observation. Cardiac disease may develop at a later stage with progression of age and disease.

• The effects of local microinjection of selective dopamine D1 and D2 receptor agonists and antagonists into the dorsal raphe nucleus on sleep and wakefulness in the rat
24 novembre 2017
Publication date: 26 February 2018
Source:Behavioural Brain Research, Volume 339

Author(s): Jaime M. Monti, Héctor Jantos

The effects of the dopamine (DA) D1 and D2 receptor agonists SKF38393, bromocriptine and quinpirole, respectively, on spontaneous sleep were analyzed in adult rats prepared for chronic sleep recordings. Local administration of the DAergic agonists into the dorsal raphe nucleus (DRN) during the light phase of the light-dark cycle induced a significant reduction of rapid-eye movement sleep (REMS) and the number of REM periods. Additionally, bromocriptine and quinpirole significantly increased wakefulness (W). Opposite, the microinjection into the DRN of the DA D1 and D2 receptor antagonists SCH23390 and sulpiride, respectively, significantly augmented REMS and the number of REM periods. Pretreatment with SCH23390 and sulpiride prevented the effects of SKF38393 and bromocriptine, respectively, on sleep variables. Our results tend to indicate that DAergic neurons located in the ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) contribute to the regulation of predominantly W and REMS by DRN serotonergic neurons.

• Relevance-dependent modulation of tactile suppression during active, passive and pantomime reach-to-grasp movements
24 novembre 2017
Publication date: 26 February 2018
Source:Behavioural Brain Research, Volume 339

Author(s): Damian M. Manzone, J. Timothy Inglis, Ian M. Franks, Romeo Chua

When we move, our ability to detect tactile events on the moving limb is reduced (e.g., movement-related tactile suppression). This process prevents unimportant sensory information from bombarding our central nervous system. This study investigated whether movement-related suppression can be modulated according to task relevance, while introducing a novel motor-driven complex upper limb movement. In three experiments, participants performed volitional self-driven and passive motor-driven reaching and grasping movements. Over the course of the movement, weak electrical stimulation was presented at task-relevant (i.e., index finger) and irrelevant sites (i.e., forearm) on the moving limb. In Experiment 1, participants displayed reduced detectability during movement (90% resting detection). This was true for all locations on the moving limb irrespective of task-relevance and during both self and motor-driven movements. In Experiments 2 and 3 a range of stimulus amplitudes were presented to one task-relevant location during both self and motor-driven movements (Experiment 2A), to a task-relevant and irrelevant site (Experiment 2B) and during a targeted and pantomime/no target reach (Experiment 3). This allowed us to estimate perceptual thresholds and assess the magnitude of movement-related suppression. During both self and motor-driven movements participants exhibited movement-related suppression. Suppression was greater at the irrelevant site (forearm) than at the relevant site (index finger) of the limb. Further, the magnitude of suppression varied with task relevance such that pantomime movements elicited more suppression than targeted movements. Collectively, these experiments suggest that although tactile suppression may be a general consequence of movement, suppression can be modulated in a relevance-dependent manner.

• Facilitated acquisition of the classically conditioned eyeblink response in active duty military expressing posttraumatic stress disorder symptoms
24 novembre 2017
Publication date: 26 February 2018
Source:Behavioural Brain Research, Volume 339

Author(s): Justin D. Handy, Pelin Avcu, Nora Ko, Alejandro Ortiz, Michael J. Doria, Richard J. Servatius

Objective Learning diathesis models underscore the role of hyper-conditioning in the development of PTSD following trauma exposure. Eyeblink classical conditioning is one method of examining associative learning biases independent of fear and threat produced by trauma. Facilitated learning is apparent in individuals self-expressing PTSD symptoms, as well as behaviorally inhibited (BI) temperament, a vulnerability factor for PTSD. Here, we examine eyeblink conditioning in active duty military personnel and relate learning with PTSD symptomology. Method Volunteers were 83 active duty United States Coast Guard personnel (18 females) recruited from small boat stations. Personnel were administered the PTSD Checklist (PCL) to assess current PTSD symptoms using DSM-IV criteria. BI temperament was assessed with the Adult Measure of Behavioural Inhibition (AMBI). Eyeblink conditioning was conducted using a partial reinforcement schedule, whereby paired trials (500-ms pure tone conditioned stimulus co-terminating with a 50-ms air-puff unconditional stimulus) were interpolated with 50% CS-alone trials. Results Consistent with previous work, there was a high degree of concordance between BI and incidence of PTSD. Further, PTSD was associated with faster learning during the acquisition period, with conditioned responding sustained through the extinction period. Conclusions These results reinforce the relationship between BI and PTSD in an active duty military sample, supporting previous observations in veteran and civilian samples. The conditioning data are consistent with predictions derived from a learning diathesis model of stress and anxiety, suggesting facilitated associative learning may represent an additional vulnerability for the development and maintenance of stress-related pathology.

• US alone trials presented during acquisition do not disrupt classical eyeblink conditioning: Empirical and computational findings
24 novembre 2017
Publication date: 15 February 2018
Source:Behavioural Brain Research, Volume 338

Author(s): M.T. Allen, C.E. Myers, D. Williams, R.J. Servatius

Studies of partial reinforcement in eyeblink conditioning have typically shown slower learning of a CS-US association when paired CS-US trials are interleaved with CS-alone trials. However, recent work has shown that CS-US learning is not slowed by interleaved US-alone trials. This discrepancy is surprising since both partial reinforcement protocols reduce the total number of paired CS-US trials. Previously, Kimble et al. (1955) reported that inserting a block of US-alone trials during CS-US training did not disrupt eyeblink acquisition. Here, we sought to replicate and extend these findings by comparing interleaved vs. blocked US-alone trials during CS-US paired training. Ninety-seven undergraduates volunteered for this experiment for research credit. Participants received 60 acquisition trials, consisting of either 100% CS-US paired trials, 50% US-alone trials intermixed with CS-US paired trials, or a block of 20 US-alone trials inserted between blocks of 20 CS-US trials. We also utilized a previously published computational model of hippocampal and cerebellar learning to test the effects of these US-alone protocols. Both empirical and computational results supported the finding that US-alone trials, either intermixed or inserted as a block of trials, do not disrupt acquisition of conditioned eyeblinks. Possible neural substrates of these US-alone effects are discussed.

• Impaired cognitive flexibility during sleep deprivation among carriers of the Brain Derived Neurotrophic Factor (BDNF) Val66Met allele
24 novembre 2017
Publication date: 15 February 2018
Source:Behavioural Brain Research, Volume 338

Author(s): Leilah K. Grant, Sean W. Cain, Anne-Marie Chang, Richa Saxena, Charles A. Czeisler, Clare Anderson

Accumulating evidence points to a genetic contribution to explain inter-individual vulnerability to sleep deprivation. A functional polymorphism in the BDNF gene, which causes a valine (Val) to methionine (Met) amino acid substitution at Codon 66, has been associated with cognitive impairment, particularly in populations with impaired frontal functioning. We hypothesised that sleep deprivation, which affects frontal function, may lead to cognitive dysfunction in Met allele carriers. To examine this, we investigated, in different BDNF genotypes, the effects of sleep deprivation on cognitive flexibility, as measured by response inhibition using the Stroop Color Naming Task. Thirty healthy, adults of European ancestry, including 12 heterozygous Met allele carriers and 18 Val/Val homozygotes, underwent 30-h of extended wakefulness under constant routine conditions. A computerised Stroop task was administered every 2h. Error rate and reaction times increased with time awake for all individuals. Participants with the Val/Met genotype made more errors on incongruent trials after 20h awake. While Val/Met participants also took significantly longer to respond when inhibiting a prepotent response irrespective of time awake, this was particularly evident during the biological night. Our study shows that carriers of the BDNF Met allele are more vulnerable to the impact of prolonged wakefulness and the biological night on a critical component of executive function, as measured by response inhibition on the Stroop task.

• The MCUCN simulation code for ultracold neutron physics
24 novembre 2017
Publication date: 11 February 2018
Source:Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Volume 881

Author(s): G. Zsigmond

Ultracold neutrons (UCN) have very low kinetic energies 0-300 neV, thereby can be stored in specific material or magnetic confinements for many hundreds of seconds. This makes them a very useful tool in probing fundamental symmetries of nature (for instance charge-parity violation by neutron electric dipole moment experiments) and contributing important parameters for the Big Bang nucleosynthesis (neutron lifetime measurements). Improved precision experiments are in construction at new and planned UCN sources around the world. MC simulations play an important role in the optimization of such systems with a large number of parameters, but also in the estimation of systematic effects, in benchmarking of analysis codes, or as part of the analysis. The MCUCN code written at PSI has been extensively used for the optimization of the UCN source optics and in the optimization and analysis of (test) experiments within the nEDM project based at PSI. In this paper we present the main features of MCUCN and interesting benchmark and application examples.

• Metastable precipitate phases in Mg–9.8 wt%Sn alloy
24 novembre 2017
Publication date: 1 February 2018
Source:Acta Materialia, Volume 144

Author(s): C.Q. Liu, H.W. Chen, H. Liu, X.J. Zhao, J.F. Nie

Aberration-corrected scanning transmission electron microscopy has been used to characterize precipitates in a binary Mg–9.8 wt%Sn alloy aged in the temperature range 100–250 °C. In contrast to the traditional view that precipitation in Mg–Sn based alloys involves exclusive formation of the equilibrium phase β (Mg2Sn, face-centered cubic), we found the formation of a GP zone and a metastable phase, designated β′, prior to the equilibrium β phase. The GP zone has a plate morphology with its habit plane parallel to the basal plane of the matrix phase. The β′ phase also has a plate morphology with its habit plane parallel to the magnesium basal plane. It has a L12 structure (space group Pm$3 ¯$m, lattice parameter a = 0.453 nm) and a Mg3Sn composition. The orientation relationship between the β′ precipitate and the magnesium matrix is such that (11$1 ¯$)β′ // (0001)α and [011]β′ // [2$1 ¯ 1 ¯$0]α. The β′ phase forms from GP zones and the magnesium matrix. Its formation is similar to the classical hcp → fcc transformation that involves generation and motion of Shockley partial dislocations on (0002)α. With prolonged ageing, some β′ precipitates transform in situ to the β phase.

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• Smartphone form factors: Effects of width and bottom bezel on touch performance, workload, and physical demand
24 novembre 2017
Publication date: February 2018
Source:Applied Ergonomics, Volume 67

Author(s): Seul Chan Lee, Min Chul Cha, Hwan Hwangbo, Sookhee Mo, Yong Gu Ji

• Identifying interactive effects of task demands in lifting on estimates of in vivo low back joint loads
24 novembre 2017
Publication date: February 2018
Source:Applied Ergonomics, Volume 67

Author(s): Chad E. Gooyers, Tyson A.C. Beach, David M. Frost, Samuel J. Howarth, Jack P. Callaghan

This investigation examined interactions between the magnitude of external load, movement speed and (a)symmetry of load placement on estimates of in vivo joint loading in the lumbar spine during simulated occupational lifting. Thirty-two participants with manual materials handling experience were included in the study. Three-dimensional motion data, ground reaction forces, and activation of six bilateral trunk muscle groups were captured while participants performed lifts with two loads at two movement speeds and using two load locations. L4-L5 joint compression and shear force-time histories were estimated using an EMG-assisted musculoskeletal model of the lumbar spine. Results from this investigation provide strong evidence that known mechanical low back injury risk factors should not be viewed in isolation. Rather, injury prevention efforts need to consider the complex interactions that exist between external task demands and their combined influence on internal joint loading.

• Physiological consequences of using an upper limb exoskeleton during manual handling tasks
24 novembre 2017
Publication date: February 2018
Source:Applied Ergonomics, Volume 67

Author(s): Jean Theurel, Kevin Desbrosses, Terence Roux, Adriana Savescu

This study aimed to assess the physiological consequences of using an upper limb exoskeleton during manual handling task, as muscle activity, upper limb kinematics, postural balance and cardiac cost. Participants performed three tasks (load lifting (LIFT), carrying (WALK) and stacking-unstacking (STACK)) with (EXOS) and without (FREE) an exoskeleton. During LIFT and STACK, the activity of the deltoid anterior muscle was significantly lower for EXOS than for FREE. During LIFT, the activity of the triceps brachii (TB) and tibialis anterior muscles significantly increased for EXO. The TB muscle activity significantly decreased for EXOS during WALK. The cardiac cost tended to increase with the use of the exoskeleton during LIFT, compared to FREE. The upper limb kinematics significantly differed between the EXOS and FREE conditions for all tasks. The benefits of the upper limb exoskeleton to reduce shoulder flexor muscle activity has been demonstrated, while broader physiological consequences have also been evidenced as increased antagonist muscle activity, postural strains, cardiovascular demand, and modified kinematics.

• Use of a footrest to reduce low back discomfort development due to prolonged standing
24 novembre 2017
Publication date: February 2018
Source:Applied Ergonomics, Volume 67

Author(s): Jeremy Yang Lee, Richelle Baker, Pieter Coenen, Leon Straker

Prolonged standing is common in many occupations and has been associated with low back discomfort (LBD). No recent studies have investigated a footrest as an intervention to reduce LBD associated with prolonged standing. This study investigated the effect of a footrest on LBD and sought to determine if LBD changes were accompanied by changes in muscle fatigue and low back end-range posture and movement. Twenty participants stood for two 2-h trials, one with and one without a footrest. LBD, lumbar erector spinae electromyography, upper lumbar (UL) and lower lumbar (LL) angles were measured. A significant increase in LBD occurred in both conditions but the footrest did not significantly decrease LBD. The only significant finding between conditions was that UL lordosis became more similar to usual standing over time with footrest use. These findings suggest that footrest use may not reduce LBD development and that development of LBD with prolonged standing is unlikely to be due to muscle fatigue or end-range posture mechanisms.

• Multi-directional one-handed strength assessments using AnyBody Modeling Systems
24 novembre 2017
Publication date: February 2018
Source:Applied Ergonomics, Volume 67

Author(s): Divyaksh Subhash Chander, Maria Pia Cavatorta

Digital human modeling tools support proactive ergonomics in optimizing work tasks and workplace layouts. Empirical-statistical model based tools are often used to estimate the force exertion capability of the operators. This work is intended to serve as an initial probing into the usability of a musculoskeletal model based software, AnyBody Modeling Systems (AMS), in evaluating the force exertion capability at different points in the workspace and for various exertion directions. As a first step, it focuses on the modeling approach and the accuracy of one-handed isometric strength estimates of AMS. An existing literature database was used to compare the predicted strength at 8 hand locations and in 26 exertion directions, while simulating the empirical postures. The results show a correlation coefficient of 0.7 between the simulated and the experimental strength. AMS emphasizes the biomechanical advantages in strength due to the alignment of force exertion direction with the shoulder. Additionally, some discrepancies have been identified and discussed.

• Your attention makes me smile: Direct gaze elicits affiliative facial expressions
24 novembre 2017
Publication date: February 2018
Source:Biological Psychology, Volume 132

Author(s): Jari K. Hietanen, Terhi M. Helminen, Helena Kiilavuori, Anneli Kylliäinen, Heidi Lehtonen, Mikko J. Peltola

Facial electromyographic responses and skin conductance responses were measured to investigate whether, in a neutral laboratory environment, another individual’s direct gaze elicits a positive or negative affective reaction in the observer. The results showed that greater zygomatic responses associated with positive affect were elicited by seeing another person with direct as compared to averted gaze. The zygomatic responses were greater in response to another person’s direct gaze both when the participant’s own gaze was directed towards the other and when the participant was not looking directly towards the other. Compatible with the zygomatic responses, the corrugator activity (associated with negative affect) was decreased below baseline more in response to another person’s direct than averted gaze. Replicating previous research, the skin conductance responses were greater to another person’s direct than averted gaze. The results provide evidence that, in a neutral context, another individual’s direct gaze is an affiliative, positive signal.

• Analysis of surface electromyography signal features on osteomyoplastic transtibial amputees for pattern recognition control architectures
24 novembre 2017
Publication date: February 2018
Source:Biomedical Signal Processing and Control, Volume 40

Author(s): Talon Garikayi, Dawie Van den Heever, Stephen Matope

This paper presents the characterisation of electromyography signals for the purpose of controlling a powered prosthetic ankle using pattern recognition algorithms. The goal is to identify the specific muscles that can be used to guarantee optimal control of a multichannel powered prosthetic ankle. SENIAM and ISEK protocols were used for signal acquisition, processing and reporting. A set of paired surface electrodes were placed above selected muscles on the residual limb. Participants were instructed to perform normal gait. The signals were recorded, labelled and analysed using the Vicon Nexus Motion Capturing System and Noraxon Myomotion System. Signal processing was performed using MR3 Software and further post processing was performed using Matlab. Time and frequency domain features were analysed. The protocol revealed that the tibialis anterior, medial and lateral gastrocnemius muscles actively generate myoelectric signals on the residual limb. A total of 12 time domain and 4 frequency domain features were successfully extracted and used in the analysis. The tibialis anterior muscle was identified as a candidate for classifying dorsiflexion with a mean amplitude of 35.08μV. The soleus muscle was inaccessible on the amputated leg and as a result only the medial and lateralis gastrocnemius muscles, with 17.40% signal power and 43.73% mean amplitude as compared to the soleus, were available for plantarflexion. There was significant difference (p&lt;0.05) between features from the amputated residual limb and those from the intact normal leg. However, there was no significant difference (p&gt;0.05) between signal features from two different participants. Sagittal plane movements were linearly discriminated with 100% accuracy for tibialis anterior and medial gastrocnemius. However, lateralis gastrocnemius exhibited a 0.0769% classification error as a result of the amputation technique.

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• Time-varying analysis of the heart rate variability during A-phases of sleep: Healthy and pathologic conditions
24 novembre 2017
Publication date: February 2018
Source:Biomedical Signal Processing and Control, Volume 40

Author(s): Guadalupe Dorantes-Méndez, Martin O. Mendez, Alfonso Alba, Liborio Parrino, Giulia Milioli

In the present study, a comparison of the heart rate variability (HRV) behavior between healthy subjects and Nocturnal Front Lobe Epilepsy (NFLE) patients was carried out during the A-phases of sleep. The A-phases are short cortical events that interrupt the basal oscillation of the sleep stages and form the cyclic alternating pattern phenomenon. HRV was assessed by means of standard temporal measures and frequency measures based on time-varying autoregressive (TVAR) models. The analysis of HRV, in relation to the A-phases occurrence, was performed selecting two segments: one before the onset of the A-phase and one during the A-phase time. The results showed a significant increment in the heart rate during the A-phases in both, healthy subjects and NFLE patients. In addition, a major participation of the sympathetic nervous system was found in both healthy and pathologic conditions based on the sympatho-vagal index (LF/HF) during A-phases. The intensity of the shift towards sympathetic activity is related of A-phase type, where the largest shift is found in A3 phases. However, the NFLE patients present a weaker autonomic response during A-phases. The results suggest that the autonomic cardiac response related with the surveillance mechanism of NFLE patients is affected.

• An efficient ECG denoising methodology using empirical mode decomposition and adaptive switching mean filter
24 novembre 2017
Publication date: February 2018
Source:Biomedical Signal Processing and Control, Volume 40

Author(s): Manas Rakshit, Susmita Das

Electrocardiogram (ECG) is a widely employed tool for the analysis of cardiac disorders. A clean ECG is often desired for proper treatment of cardiac ailments. However, in the real scenario, ECG signals are corrupted with various noises during acquisition and transmission. In this article, an efficient ECG denoising methodology using combined empirical mode decomposition (EMD) and adaptive switching mean filter (ASMF) is proposed. The advantages of both EMD and ASMF techniques are exploited to reduce the noises in the ECG signals with minimum distortion. Unlike conventional EMD based techniques, which reject the initial intrinsic mode functions (IMFs) or utilize a window based approach for reducing high-frequency noises, here, a wavelet based soft thresholding scheme is adopted for reduction of high-frequency noises and preservation of QRS complexes. Subsequently, an ASMF operation is performed to enhance the signal quality further. The ECG signals of standard MIT-BIH database are used for the simulation study. Three types of noises in particular white Gaussian noise, Electromyogram (EMG) and power line interference contaminate the test ECG signals. Three standard performance metrics namely output SNR improvement, mean square error, and percentage root mean square difference measure the efficacy of the proposed technique at various signal to noise ratio (SNR). The proposed denoising methodology is compared with other existing ECG denoising approaches. A detail qualitative and quantitative study and analysis indicate that the proposed technique can be used as an effective tool for denoising of ECG signals and hence can serve for better diagnostic in computer-based automated medical system.

• Dimensionality effect of myoelectric-controlled interface on the coordination of agonist and antagonist muscles during voluntary isometric elbow flexion and extension
24 novembre 2017
Publication date: February 2018
Source:Biomedical Signal Processing and Control, Volume 40

Author(s): Wenbo Sun, Jiaqi Wang, Linchuan Deng, Huihua Liu, Tiebin Yan, Rong Song

This study aimed to investigate the dimensionality effect of myoelectric-controlled interface (MCI) on the coordination of agonist and antagonist muscles during voluntary isometric elbow flexion and extension. Eighteen healthy subjects were recruited to control a controllable cursor to track a target cursor by real-time modulating the biceps and triceps activities within one-dimensional and two-dimensional MCIs. Electromyographic (EMG) signals were collected to calculate the normalized muscle activation, while the slope of the best-fitting linear relationship between the normalized agonist and antagonist activations was used to quantify the muscle co-activation. The tracking error and the normalized net torque of the elbow joint were also calculated. Results showed that no significant difference was found in the tracking error between one-dimensional and two-dimensional MCIs. The normalized antagonist activation, the muscle co-activation and the normalized net torque were significantly lower within two-dimensional MCI than within one-dimensional MCI. In addition, significant decrease in the normalized agonist activation was also found during elbow extension. These results implied that within two-dimensional MCI, subjects were able to modulate the coordination of agonist and antagonist precisely by inhibiting unnecessary muscle activities. Therefore, two-dimensional MCI might be applied as a rehabilitation tool aiming at fine control of abnormal muscle coordination.

• Surface EMG based continuous estimation of human lower limb joint angles by using deep belief networks
24 novembre 2017
Publication date: February 2018
Source:Biomedical Signal Processing and Control, Volume 40

Author(s): Jiangcheng Chen, Xiaodong Zhang, Yu Cheng, Ning Xi

Surface electromyography (EMG) signals have been widely used in locomotion studies and human-machine interface applications. In this paper, a regression model which relates the multichannel surface EMG signals to human lower limb flexion/extension (FE) joint angles is constructed. In the experimental paradigm, three dimensional trajectories of 16 external markers on the human lower limbs were recorded by optical motion capture system and surface EMG signals from 10 muscles directly concerned with the lower limb motion were recorded synchronously. With the raw data, the joint angles of hip, knee and ankle were calculated accurately and the time series of intensity for surface EMG signals were extracted. Then, a deep belief networks (DBN) that consists of restricted Boltzmann machines (RBM) was built, by which the multi-channel processed surface EMG signals were encoded in low dimensional space and the optimal features were extracted. Finally, a back propagation (BP) neural network was used to map the optimal surface EMG features to the FE joint angles. The results show that, the features extracted from multichannel surface EMG signals using DBN method proposed in this paper outperform principal components analysis (PCA), and the root mean square error (RMSE) between the estimated joint angles and calculated ones during human walking is reduced by about 50%. The proposed model is expected to develop human-machine interaction interface to achieve continuous bioelectric control and to improve motion stability between human and machine, especially for lower limb wearable intelligent equipment.

• A systematic review on fatigue analysis in triceps brachii using surface electromyography
24 novembre 2017
Publication date: February 2018
Source:Biomedical Signal Processing and Control, Volume 40

Author(s): Jawad Hussain, Kenneth Sundaraj, Yin Fen Low, Lam Chee Kiang, Sebastian Sundaraj, Md. Asraf Ali

Objective The objective of this research was to summarize and analyse the research findings regarding analysis of fatigue in the human triceps brachii (TB) muscle through surface electromyography (sEMG) observations. Methods We systematically searched through five major online scientific databases namely the PubMed, Science Direct, Wiley Online, Springer Link and SCOPUS databases, for articles written in the English language from the year 2001 to March 2017. We specifically searched for the words/phrases “surface electromyography” OR “sEMG” AND “muscle fatigue” AND “triceps” in the title, abstract and keywords to narrow our search and identified 291 articles, of which, 52 were found potentially the most relevant. Results Of 52 considered articles, 11 analysed fatigue in sports, 11 investigated rehabilitation, 15 considered exercises or trainings, 5 used TB as a co-activator or antagonist, and 5 contemplated elbow extension movements. In addition, 4 of the articles investigated both elbow flexors and extensors and 1 studied training effects in rehabilitation. Conclusion Although, many studies in this particular field have considered the TB, further investigations are required to explain some specific facts about fatigue in the TB. The compensation strategy that muscles use to overcome fatigue, the stabilization, overcoming of errors during fatigue along with effect of mental load on brachii muscles and the effect of sports drinks and other eatables on fatigue are a few potential zones that require further in-depth research. This study will guide and direct new researchers to areas that remain hidden.

• Humidity and CO2 gas sensing properties of double-layer graphene
24 novembre 2017
Publication date: February 2018
Source:Carbon, Volume 127

Author(s): Xuge Fan, Karim Elgammal, Anderson D. Smith, Mikael Östling, Anna Delin, Max C. Lemme, Frank Niklaus

Graphene has interesting gas sensing properties with strong responses of the graphene resistance when exposed to gases. However, the resistance response of double-layer graphene when exposed to humidity and gasses has not yet been characterized and understood. In this paper we study the resistance response of double-layer graphene when exposed to humidity and CO2, respectively. The measured response and recovery times of the graphene resistance to humidity are on the order of several hundred milliseconds. For relative humidity levels of less than ∼3% RH, the resistance of double-layer graphene is not significantly influenced by the humidity variation. We use such a low humidity atmosphere to investigate the resistance response of double-layer graphene that is exposed to pure CO2 gas, showing a consistent response and recovery behaviour. The resistance of the double-layer graphene decreases linearly with increase of the concentration of pure CO2 gas. Density functional theory simulations indicate that double-layer graphene has a weaker gas response compared to single-layer graphene, which is in agreement with our experimental data. Our investigations contribute to improved understanding of the humidity and CO2 gas sensing properties of double-layer graphene which is important for realizing viable graphene-based gas sensors in the future.

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• Distinct modulation of interhemispheric inhibitory mechanisms during movement preparation reveals the influence of cognition on action control
24 novembre 2017
Publication date: February 2018
Source:Cortex, Volume 99

Author(s): Mark R. Hinder, Rohan Puri, Sarah Kemp, Sara Waitzer, Paola Reissig, Tino Stöckel, Hakuei Fujiyama

When selecting actions based on visual warning stimuli (WS), corticospinal excitability (CSE) is initially suppressed, consistent with a neural mechanism to prevent premature release of the competing responses. Despite being implicated in between-hand movement selection and preparation, the role that interhemispheric inhibition (IHI) may play in this ‘impulse control’ mechanism is not known. Participants performed a warned, between-hand, choice reaction time (RT) task in which the informativeness of the WS (with regards to which hand would be required to respond) was manipulated. Transcranial magnetic stimulation (TMS) assessed CSE of the right primary motor cortex (M1) and IHI from left to right M1 with 10 (IHI10) and 40 (IHI40) msec interstimulus intervals during movement selection and preparation. Consistent with impulse control, CSE was initially suppressed prior to both left and right hand actions, irrespective of WS informativeness. Subsequent CSE increases occurred in the responding hand which were larger, and occurred earlier, following an informative WS. Importantly, these increases strongly predicted response times. In contrast to the generic CSE suppression, an informative WS permitted a hand-specific release of IHI10 in the responding hand, whereas IHI40 was released in both hands. As releases of IHI cannot explain a simultaneous suppression of CSE, this suggests several distinct movement preparation mechanisms are at play with IHI modulation occurring independently from impulse control. Notably, the findings support the notion that IHI10 and IHI40 between contralateral motor regions are mediated by discrete transcallosal pathways, and are differently modulated by specific motor and cognitive attributes of a rapid choice task.

• Stuttering adults' lack of pre-speech auditory modulation normalizes when speaking with delayed auditory feedback
24 novembre 2017
Publication date: February 2018
Source:Cortex, Volume 99

Author(s): Ayoub Daliri, Ludo Max

Auditory modulation during speech movement planning is limited in adults who stutter (AWS), but the functional relevance of the phenomenon itself remains unknown. We investigated for AWS and adults who do not stutter (AWNS) (a) a potential relationship between pre-speech auditory modulation and auditory feedback contributions to speech motor learning and (b) the effect on pre-speech auditory modulation of real-time versus delayed auditory feedback. Experiment I used a sensorimotor adaptation paradigm to estimate auditory-motor speech learning. Using acoustic speech recordings, we quantified subjects' formant frequency adjustments across trials when continually exposed to formant-shifted auditory feedback. In Experiment II, we used electroencephalography to determine the same subjects' extent of pre-speech auditory modulation (reductions in auditory evoked potential N1 amplitude) when probe tones were delivered prior to speaking versus not speaking. To manipulate subjects' ability to monitor real-time feedback, we included speaking conditions with non-altered auditory feedback (NAF) and delayed auditory feedback (DAF). Experiment I showed that auditory-motor learning was limited for AWS versus AWNS, and the extent of learning was negatively correlated with stuttering frequency. Experiment II yielded several key findings: (a) our prior finding of limited pre-speech auditory modulation in AWS was replicated; (b) DAF caused a decrease in auditory modulation for most AWNS but an increase for most AWS; and (c) for AWS, the amount of auditory modulation when speaking with DAF was positively correlated with stuttering frequency. Lastly, AWNS showed no correlation between pre-speech auditory modulation (Experiment II) and extent of auditory-motor learning (Experiment I) whereas AWS showed a negative correlation between these measures. Thus, findings suggest that AWS show deficits in both pre-speech auditory modulation and auditory-motor learning; however, limited pre-speech modulation is not directly related to limited auditory-motor adaptation; and in AWS, DAF paradoxically tends to normalize their otherwise limited pre-speech auditory modulation.

• Role of microRNAs in senescence and its contribution to peripheral neuropathy in the arsenic exposed population of West Bengal, India
24 novembre 2017
Publication date: February 2018
Source:Environmental Pollution, Volume 233

Author(s): Debmita Chatterjee, Apurba Bandyopadhyay, Nilendu Sarma, Santanu Basu, Tarit Roychowdhury, Sib Sankar Roy, Ashok K. Giri

Arsenic induced senescence (AIS) has been identified in the population of West Bengal, India very recently. Also there is a high incidence of arsenic induced peripheral neuropathy (PN) throughout India. However, the epigenetic regulation of AIS and its contribution in arsenic induced PN remains unexplored. We recruited seventy two arsenic exposed and forty unexposed individuals from West Bengal to evaluate the role of senescence associated miRNAs (SA-miRs) in AIS and their involvement if any, in PN. The downstream molecules of the miRNA associated with the disease outcome, was also checked by immuoblotting. In vitro studies were conducted with HEK 293 cells and sodium arsenite exposure. Our results show that all the SA-miRs were upregulated in comparison to unexposed controls. miR-29a was the most significantly altered, highest expression being in the arsenic exposed group with PN, suggesting its association with the occurrence of PN. We looked for the expression of peripheral myelin protein 22 (PMP22), a specific target of miR-29a associated with myelination and found that both in vitro and in vivo results showed over-expression of the protein. Since this was quite contrary to miRNA regulation, we checked for intermediate players β-catenin and GSK-3β upon arsenic exposure which affects PMP22 expression. We found that β-catenin was upregulated in vitro and was also highest in the arsenic exposed group with PN while GSK-3β followed the reverse pattern. Our findings suggest that arsenic exposure alters the expression of SA-miRs and the mir-29a/beta catenin/PMP22 axis might be responsible for arsenic induced PN.

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• A concentric flow slot burner for stabilizing turbulent partially premixed inhomogeneous flames of gaseous fuels
24 novembre 2017
Publication date: February 2018
Source:Experimental Thermal and Fluid Science, Volume 91

Author(s): Mohy S. Mansour, Heinz Pitsch, Stephan Kruse, Mohamed F. Zayed, Mohamed S. Senosy, Mrinal Juddoo, Joachim Beeckmann, Assaad R. Masri

Combustion of turbulent inhomogeneous mixtures of air and fuel is common in many practical systems providing improved stability for both gaseous and liquid fuels. Understanding the structure and stability of turbulent flames in this mode has been the aim of many research groups who employed special burner designs to control the fuel and air mixing process. In this work, a modified design inspired by the Wolfhard-Parker slot burner was developed for planar turbulent flames with inlet conditions that are overall lean yet either compositionally inhomogeneous or partially premixed. The new burner is referred as the Concentric Flow Slot Burner (CFSB). The stability characteristics and flame structure are investigated for methane and natural gas fuels using planar laser induced fluorescence of C2Hx and high speed PLIF-OH. The effects of the jet equivalence ratio, the level of inhomogeneity, and the Reynolds number are investigated in this work. The data show that the flames with inhomogeneous mixture are more stable than fully premixed flames. Lean flames are stabilized in the CFSB burner. Stability is significantly improved by the use of a hollow truncated rectangular pyramid nozzle at the burner exit. The reaction zone structure varies significantly in the current burner from thin structures in rich flames to distributed with thick preheat zones in lean flames. The effect of the level of inhomogeneity on the reaction zone structure is presented and discussed. The new CFSB burner is able to generate a wide range of turbulent planar flames spanning the entire range from non-premixed to fully premixed flames. In addition, the high stability level of the burner allows for the study of highly turbulent flames of practical interest.

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• Modifications in lower leg muscle activation when walking barefoot or in minimalist shoes across different age-groups
24 novembre 2017
Publication date: February 2018
Source:Gait &amp; Posture, Volume 60

Author(s): Simon Franklin, François-Xavier Li, Michael J. Grey

Ageing is associated with a decline in muscle strength and impaired sensory mechanisms which contribute to an increased risk of falls. Walking barefooted has been suggested to promote increased muscle strength and improved proprioceptive sensibility through better activation of foot and ankle musculature. Minimalist footwear has been marketed as a method of reaping the suggested benefits of barefoot walking whilst still providing a protective surface. The aim of this study was to investigate if walking barefoot or in minimalist footwear provokes increased muscle activation compared to walking in conventional footwear. Seventy healthy adults (age range 20–87) volunteered for this study. All participants walked along a 7m walking lane five times in four different footwear conditions (barefoot (BF), minimalist shoes (MSH), their own shoes (SH) and control shoes (CON)). Muscle activity of their tibialis anterior (TA), gastrocnemius medialis (GCM) and peroneus longus (PL) were recorded simultaneously and normalised to the BF condition. MSH are intermediate in terms of ankle kinematics and muscle activation patterns. Walking BF or in MSH results in a decrease in TA activity at initial stance due to a flatter foot at contact in comparison to conventional footwear. Walking BF reduces PL activity at initial stance in the young and middle age but not the old. Walking in supportive footwear appears to reduce the balance modulation role of the GCM in the young and middle age but not the old, possibly as a result of slower walking speed when BF.

• EMG normalization method based on grade 3 of manual muscle testing: Within- and between-day reliability of normalization tasks and application to gait analysis
24 novembre 2017
Publication date: February 2018
Source:Gait &amp; Posture, Volume 60

Author(s): Anne Tabard-Fougère, Kevin Rose-Dulcina, Vincent Pittet, Romain Dayer, Nicolas Vuillerme, Stéphane Armand

Electromyography (EMG) is an important parameter in Clinical Gait Analysis (CGA), and is generally interpreted with timing of activation. EMG amplitude comparisons between individuals, muscles or days need normalization. There is no consensus on existing methods. The gold standard, maximum voluntary isometric contraction (MVIC), is not adapted to pathological populations because patients are often unable to perform an MVIC. The normalization method inspired by the isometric grade 3 of manual muscle testing (isoMMT3), which is the ability of a muscle to maintain a position against gravity, could be an interesting alternative. The aim of this study was to evaluate the within- and between-day reliability of the isoMMT3 EMG normalizing method during gait compared with the conventional MVIC method. Lower limb muscles EMG (gluteus medius, rectus femoris, tibialis anterior, semitendinosus) were recorded bilaterally in nine healthy participants (five males, aged 29.7±6.2years, BMI 22.7±3.3kgm−2) giving a total of 18 independent legs. Three repeated measurements of the isoMMT3 and MVIC exercises were performed with an EMG recording. EMG amplitude of the muscles during gait was normalized by these two methods. This protocol was repeated one week later. Within- and between-day reliability of normalization tasks were similar for isoMMT3 and MVIC methods. Within- and between-day reliability of gait EMG normalized by isoMMT3 was higher than with MVIC normalization. These results indicate that EMG normalization using isoMMT3 is a reliable method with no special equipment needed and will support CGA interpretation. The next step will be to evaluate this method in pathological populations.

• The activation of transversus abdominis muscle during rapid limb movements depends on the anticipation of postural demand rather than on respiratory reflexes
24 novembre 2017
Publication date: February 2018
Source:Gait &amp; Posture, Volume 60

Author(s): Hugo Massé-Alarie, Louis-David Beaulieu, Richard Preuss, Cyril Schneider

• Effect of robotic-assisted gait rehabilitation on dynamic equilibrium control in the gait of children with cerebral palsy
24 novembre 2017
Publication date: February 2018
Source:Gait &amp; Posture, Volume 60

Author(s): L. Wallard, G. Dietrich, Y. Kerlirzin, J. Bredin

Due to the intensity and repetition of movement, roboticassisted gait training therapy could have a beneficial effect on the recovery and improvement of postural and locomotor functions of the patient. This study sought to highlight the effects of robotic-assisted gait rehabilitation in gait of children with Cerebral Palsy (CP). We analyzed the different strategies before and after this rehabilitation which was used in order to generate forward motion while maintaining balance. Data were collected by a motion analysis system (Vicon® - Oxford Metrics, Oxford, UK). The children were divided into two groups in such a way as to obtain a randomized controlled population: i) a group of fourteen children (Treated Group) underwent 20 sessions of roboticassisted gait training therapy using the driven gait orthosis Lokomat®Pediatric (Hocoma AG, Volketswil, Switzerland) compared to ii) a group of sixteen children without sessions of Lokomat®Pediatric (Control Group). Significant differences are observed for the TG between the preand post-test values of the locomotor parameters and of the kinetic data of the propulsive forces of the Center of Mass (COM) and of the Center of Pressure (COP) dynamic trajectory. This first study, although performed on a limited number of patients, shows the usefulness of this robotic gait rehabilitation mainly in the balance control in gait. Indeed after this rehabilitation, these children improve their gait that is especially characterized by a more appropriate time lag between the time instant of COM-COP trajectory divergence and the time instant when the forward propulsive forces became apparent.

• Neuromuscular compensatory strategies at the trunk and lower limb are not resolved following an ACL reconstruction
24 novembre 2017
Publication date: February 2018
Source:Gait &amp; Posture, Volume 60

Author(s): Grant Boggess, Kristin Morgan, Darren Johnson, Mary Lloyd Ireland, Jeffrey A. Reinbolt, Brian Noehren

Background Following anterior cruciate ligament reconstruction (ACLR), patients present with greater trunk ipsilateral lean, which may affect knee kinetics and increase re-injury risk. However, there has been little research into neuromuscular factors controlling the trunk and their relation to the knee between healthy and ACLR subjects. This is critical to establish in order to develop more directed and effective interventions. Hypothesis As compared to healthy control subjects, ACLR subjects will demonstrate increased erector spinae and rectus abdominis co-contraction, greater rectus abdominis force and greater hamstring force that is correlated to increased forward trunk lean. Study design Cross-sectional study, Level of Evidence: 3. Methods Eleven healthy and eleven ACLR subjects were matched for age, mass and height. Subjects were asked to run at a self-selected speed while instrumented gait analysis was performed. An anthropometrically scaled OpenSim model was created for each subject. Trunk and hamstring muscle forces from Static Optimization were analyzed at impact peak. Additionally, directed co-contraction ratios were calculated for the erector spinae and erector spinae/rectus abdominis combinations. Results ACLR subjects showed more balanced erector spinae co-contraction [p&lt;0.01], and greater hamstring force [biceps femoris long head (p=0.02), semimembranosus (0.01), semitendinosus (0.01)]. There was no statistical difference for any other muscle group. Conclusion Despite release to return to sport, ACLR subjects are continuing to increase the stiffness of their trunk as well increase their hamstring force to potentially reduce anterior tibial translation. Clinical relevance Clinicians may anticipate ACLR subjects using their erector spinae and hamstrings to maintain a sense of stability in their trunk and at their knee.

• New constraints on Xe incorporation mechanisms in olivine from first-principles calculations
24 novembre 2017
Publication date: 1 February 2018
Source:Geochimica et Cosmochimica Acta, Volume 222

Author(s): Céline Crépisson, Marc Blanchard, Michele Lazzeri, Etienne Balan, Chrystèle Sanloup

Storage of Xe at depth in silicate minerals has recently been proposed to explain the low Xe abundance in the Earth’s and Mars’ atmospheres compared to other noble gases (the so-called ‘Missing Xenon’ issue). Evidences for incorporation, and thus reactivity of Xe in olivine at high pressure and high temperature are based on variations in cell parameters and the appearance of a new Raman band. To constrain the, so far only hypothetical, Xe incorporation mechanism in olivine, we theoretically investigated models of Xe-bearing olivine using density functional theory. Three types of incorporation mechanisms are tested: Xe for Si and Xe for Mg substitutions, and interstitial Xe. Xe for Si substitution, implying an oxidation of Xe, is found to be the only mechanism consistent with experimental observations, leading to an increase of cell parameter a and the appearance of a new Raman band around 720–750 cm−1 associated with XeO stretching vibrations. Raman spectroscopy makes it possible to identify Xe incorporation site, even at low Xe content, due to high Xe polarizability. An estimation of Xe content in olivine, based on present work and previous in situ experimental results, shows that up to 0.4 at.% Xe could be stored in olivine at depth.

• The effects of trunk extensor and abdominal muscle fatigue on postural control and trunk proprioception in young, healthy individuals
24 novembre 2017
Publication date: February 2018
Source:Human Movement Science, Volume 57

Author(s): Dennis J. Larson, Stephen H.M. Brown

The purpose of this study was to induce both trunk extensor and abdominal muscle fatigue, on separate occasions, and compare their effects on standing postural control and trunk proprioception, as well as look at the effects of a recovery period on these outcome measures. A total of 20 individuals participated, with 10 (5 males and 5 females) completing either a standing postural control or lumbar axial repositioning protocol. Participants completed their randomly assigned protocol on two occasions, separated by at least 4  days, with either their trunk extensor or abdominal muscles being fatigued on either day. Postural control centre of pressure variables and trunk proprioception errors were compared pre- and post-fatigue. Results showed that both trunk extensor and abdominal muscle fatigue significantly degraded standing postural control immediately post-fatigue, with recovery occurring within 2 min post-fatigue. In general, these degradative effects on postural control appeared to be greater when the trunk extensor muscles were fatigued compared to the abdominal muscles. No statistically significant changes in trunk proprioception were found after either fatigue protocol. The present findings demonstrate our body’s ability to quickly adapt and reweight somatosensory information to maintain postural control and trunk proprioception, as well as illustrate the importance of considering the abdominal muscles, along with the trunk extensor muscles, when considering the impact of fatigue on trunk movement and postural control.

• Changes of lumbar posture and tissue loading during static trunk bending
24 novembre 2017
Publication date: February 2018
Source:Human Movement Science, Volume 57

Author(s): Faisal Alessa, Xiaopeng Ning

Static trunk bending is an occupational risk factor for lower back pain (LBP). When assessing relative short duration trunk bending tasks, existing studies mostly assumed unchanged spine biomechanical responses during task performance. The purpose of the current study was to assess the biomechanical changes of lumbar spine during the performance of relatively short duration, sustained trunk bending tasks. Fifteen participants performed 40-s static trunk bending tasks in two different trunk angles (30° or 60°) with two different hand load levels (0 or 6.8 kg). Results of the current study revealed significantly increased lumbar flexion and lumbar passive moment during the 40 s of trunk bending. Significantly reduced lumbar and abdominal muscle activities were also observed in most conditions. These findings suggest that, during the performance of short duration, static trunk bending tasks, a shift of loading from lumbar active tissues to passive tissues occurs naturally. This mechanism is beneficial in reducing the accumulation of lumbar muscle fatigue; however, lumbar passive tissue creep could be introduced due to prolonged or repetitive exposure.

• Responses of human ankle muscles to mediolateral balance perturbations during walking
24 novembre 2017
Publication date: February 2018
Source:Human Movement Science, Volume 57

Author(s): A.L. Hof, J. Duysens

During walking our balance is maintained by muscle action. In part these muscle actions automatically respond to the imbalance. This paper considers responses to balance perturbations in muscles around the ankle, peroneus longus (PL), tibialis anterior (TA) and soleus (SO). It is investigated if their action is related to previously observed balance mechanisms: the ‘braking reaction’ and the mediolateral ankle strategy. Subjects walked on a treadmill and received pushes to the left and pulls to the right in various phases of the gait cycle. Muscle actions were divided into medium latency R1 (100–150 ms), long latency R2 (170–250 ms), and late action R3 (270–350 ms). Short latency responses, before 100 ms, were not observed but later responses were prominent. With inward perturbations (e.g. pushes to the left shortly before or during stance of the right foot) responses in RPL were seen. The forward roll-over of the CoP was briefly stalled in mid stance, so that the heel was not lifted. Stance was shortened. With outward perturbations, pushes to the left shortly before or during stance of the left foot, responses in all three muscles, LTA, LSO, and LPL were seen. Our interpretation is that these muscle activations induce a ‘braking reaction’ but could also contribute to the ‘mediolateral ankle strategy’. The resultant balance correction is small but fast, and so diminishes the need for later corrections by the stepping strategy.

• Hierarchical control for flexible microgrid based on three-phase voltage source inverters operated in parallel
24 novembre 2017
Publication date: February 2018
Source:International Journal of Electrical Power &amp; Energy Systems, Volume 95

Author(s): Islam Ziouani, Djamel Boukhetala, Abdel-Moumen Darcherif, Bilal Amghar, Ikram El Abbassi

In this paper, a hierarchical control for flexible operation of a microgrid is proposed. The structure of the hierarchical control consists of inner, primary and secondary levels. The inner control is used to regulate the output voltage of the inverter which is commonly referred as zero-level. The primary control based on the universal droop control which we improve it to handle both operation modes. It is used to share the active and reactive power accurately with regardless of the output impedance of the inverters. The secondary control compensates the deviation of the microgrid voltage caused by the primary control as well as synchronizes the microgrid voltage with the grid for a smooth transition. Thus, the microgrid can operate either in grid-connected or in islanded mode by using the same control scheme. The small-signal stability of the ameliorated universal droop control is analyzed for both modes, and other levels of control are modeled. Moreover, a technique based on meta-heuristic optimization to design the hierarchical control parameters optimally is introduced. Finally, the simulation was performed on a microgrid that has three voltage source inverters (VSIs) connected in parallel and a local nonlinear load. The results demonstrate the disturbance rejection performance and the flexibility of the proposed control scheme.

• Building predictive models of emotion with functional near-infrared spectroscopy
24 novembre 2017
Publication date: February 2018
Source:International Journal of Human-Computer Studies, Volume 110

Author(s): Danushka Bandara, Senem Velipasalar, Sarah Bratt, Leanne Hirshfield

We demonstrate the capability of discriminating between affective states on the valence and arousal dimensions using functional near-infrared spectroscopy (fNIRS), a practical non-invasive device that benefits from its ability to localize activation in functional brain regions with spatial resolution superior to the Electroencephalograph (EEG). The high spatial resolution of fNIRS enables us to identify the neural correlates of emotion with spatial precision comparable to fMRI, but without requiring the use of the constricting and impractical fMRI scanner. We make these predictions across subjects, creating the capacity to generalize the model to new participants. We designed the experiment and evaluated our results in the context of a prior experiment—based on the same basic protocol and stimulus materials—which used EEG to measure participants’ valence and arousal. The F1-scores achieved by our classifiers suggest that fNIRS is particularly useful at distinguishing between high and low levels of valence (F1-score of 0.739), which has proven to be difficult to measure with physiological sensors.

• Some characterizations of finite σ-soluble PσT-groups
24 novembre 2017
Publication date: 1 February 2018
Source:Journal of Algebra, Volume 495

Author(s): Alexander N. Skiba

Let $σ = { σ i | i ∈ I }$ be some partition of the set of all primes $P$ and G a finite group. G is said to be σ-soluble if every chief factor $H / K$ of G is a $σ i$-group for some $i = i ( H / K )$. A set $H$ of subgroups of G is said to be a complete Hall σ-set of G if every member ≠1 of $H$ is a Hall $σ i$-subgroup of G for some $σ i ∈ σ$ and $H$ contains exactly one Hall $σ i$-subgroup of G for every $i ∈ I$ such that $σ i ∩ π ( G ) ≠ ∅$. A subgroup A of G is said to be σ-permutable in G if G has a complete Hall σ-set $H$ such that $A H x = H x A$ for all $x ∈ G$ and all $H ∈ H$. We obtain characterizations of finite σ-soluble groups G in which σ-permutability is a transitive relation in G.

• Power frequency spectrum analysis of surface EMG signals of upper limb muscles during elbow flexion – A comparison between healthy subjects and stroke survivors
24 novembre 2017
Publication date: February 2018
Source:Journal of Electromyography and Kinesiology, Volume 38

Author(s): Silvija Angelova, Simeon Ribagin, Rositsa Raikova, Ivanka Veneva

After a stroke, motor units stop working properly and large, fast-twitch units are more frequently affected. Their impaired functions can be investigated during dynamic tasks using electromyographic (EMG) signal analysis. The aim of this paper is to investigate changes in the parameters of the power/frequency function during elbow flexion between affected, non-affected, and healthy muscles. Fifteen healthy subjects and ten stroke survivors participated in the experiments. Electromyographic data from 6 muscles of the upper limbs during elbow flexion were filtered and normalized to the amplitudes of EMG signals during maximal isometric tasks. The moments when motion started and when the flexion angle reached its maximal value were found. Equal intervals of 0.3407 s were defined between these two moments and one additional interval before the start of the flexion (first one) was supplemented. For each of these intervals the power/frequency function of EMG signals was calculated. The mean ( MNF ) and median frequencies ( MDF ), the maximal power ( MPw ) and the area under the power function ( APw ) were calculated. MNF was always higher than MDF . A significant decrease in these frequencies was found in only three post-stroke survivors. The frequencies in the first time interval were nearly always the highest among all intervals. The maximal power was nearly zero during first time interval and increased during the next ones. The largest values of MPw and APw were found for the flexor muscles and they increased for the muscles of the affected arm compared to the non-affected one of stroke survivors.

• Reliability of the knee muscle co-contraction index during gait in young adults with and without knee injury history
24 novembre 2017
Publication date: February 2018
Source:Journal of Electromyography and Kinesiology, Volume 38

Author(s): Maurice Mohr, Kristin Lorenzen, Luz Palacios-Derflingher, Carolyn Emery, Benno M. Nigg

Despite the frequent use of the electromyography-based muscle co-contraction index (CCI) to examine muscular control of the knee joint in young adults with and without knee injury history, the reliability of the CCI in this population is unknown. The purpose of this study was to quantify within-day and between-day reliability of the knee muscle CCI during gait in young adults with and without knee injury history. Twenty young adults (10 males, 10 females) with and without history of intra-articular knee injury performed repeated gait analyses on two different days. Surface electromyography of periarticular knee muscles was performed to determine CCIs for medial and lateral knee extensor – flexor pairs. Absolute (Bland-Altman ratio limits of agreement) and relative (ICCs) reliability were determined between two sessions on the same day as well as on different days. Within-day reliability was good to excellent for most analyzed co-contraction outcomes (ICCs &gt; 0.9) and was deemed acceptable in the context of clinically relevant changes in co-contraction in response to interventions. Between two separate days, the CCI showed poor reliability with measurement errors of up to 300% and was consequently not recommended as a tool to monitor long-term changes or group differences in knee muscular control.

• Localised sampling of myoelectric activity may provide biased estimates of cocontraction for gastrocnemius though not for soleus and tibialis anterior muscles
24 novembre 2017
Publication date: February 2018
Source:Journal of Electromyography and Kinesiology, Volume 38

Author(s): Maria Vinti, Jean-Michel Gracies, Marco Gazzoni, Taian Vieira

Proper muscle activity quantification is highly relevant to monitor and treat spastic cocontraction. As activity may distribute unevenly within muscle volumes, particularly for pennate calf muscles, surface electromyograms (EMGs) detected by traditional bipolar montage may provide biased estimations of muscle activity. We compared cocontraction estimates obtained using bipolar vs grids of electrodes (high-density EMG, HD-EMG). EMGs were collected from medial gastrocnemius, soleus and tibialis anterior during isometric plantar and dorsi-flexion efforts at three levels (30%, 70% and 100% MVC), knee flexed and extended. Cocontraction index (CCI) was estimated separately for each electrode pair in the grid. While soleus and tibialis anterior CCI estimates did not depend on the detection system considered, for gastrocnemius bipolar electrodes provided larger cocontraction estimates than HD-EMG at highest effort levels, at both knee angles (ANOVA; P &lt; .001). Interestingly, HD-EMG detected greater gastrocnemius EMGs distally during plantar flexions, and greater CCI values proximally during dorsiflexions. These results suggest that bipolar electrodes: (i) provide reliable estimates of soleus and tibialis anterior cocontraction; (ii) may under-or overestimate gastrocnemius cocontraction, depending on their distal or proximal position.

Mis à jour le 03 avril 2013