Does the instruction influence voluntary force production regardless of gender during a handgrip exercise ?

International audienceThe aim of this study was to compare the results ofmaximal voluntary contraction (MVC) andmaximal rate of force development (MRFD) in women andmen during handgrip exerciseperformed following three different instructions:Oral instruction (OI):Started with audible trippingandaccompanied by encouragement during the whole muscle contraction. Triggered instruction(TI): Same as oral instruction, but without encouragement. Self-initiated instruction (SI): Thesubject himself decided to start and to stop the contraction.Women’s MVC and MRFD withOIwere higherthan SI. No significant differencehas been found between instructions in men. Ourresults suggested that women are more sensitive to the instructioneffect compared to men. Furtherexplanations will be proposed using surface EMG and fMRI measurements

A spectral-based approach for BCG signal content classification

This paper has two objectives: the first is to generate two binary flags to indicate useful frames permitting the measurement of cardiac and respiratory rates from Ballistocardiogram (BCG) signals—in fact, human body activities during measurements can disturb the BCG signal content, leading to difficulties in vital sign measurement; the second objective is to achieve refined BCG signal segmentation according to these activities. The proposed framework makes use of two approaches: an unsupervised classification based on the Gaussian Mixture Model (GMM) and a supervised classification based on K-Nearest Neighbors (KNN). Both of these approaches consider two spectral features, namely the Spectral Flatness Measure (SFM) and Spectral Centroid (SC), determined during the feature extraction step. Unsupervised classification is used to explore the content of the BCG signals, justifying the existence of different classes and permitting the definition of useful hyper-parameters for effective segmentation. In contrast, the considered supervised classification approach aims to determine if the BCG signal content allows the measurement of the heart rate (HR) and the respiratory rate (RR) or not. Furthermore, two levels of supervised classification are used to classify human-body activities into many realistic classes from the BCG signal (e.g., coughing, holding breath, air expiration, movement, et al.). The first one considers frame-by-frame classification, while the second one, aiming to boost the segmentation performance, transforms the frame-by-frame SFM and SC features into temporal series which track the temporal variation of the measures of the BCG signal. The proposed approach constitutes a novelty in this field and represents a powerful method to segment BCG signals according to human body activities, resulting in an accuracy of 94.6%

Glial Cells Missing 1 Regulates Equine Chorionic Gonadotrophin Beta Subunit via Binding to the Proximal Promoter

Equine chorionic gonadotrophin (eCG) is a placental glycoprotein critical for early equine pregnancy and used therapeutically in a number of species to support reproductive activity. The factors in trophoblast that transcriptionally regulate eCGβ-subunit (LHB), the gene which confers the hormones specificity for the receptor, are not known. The aim of this study was to determine if glial cells missing 1 regulates LHB promoter activity. Here, studies of the LHB proximal promoter identified four binding sites for glial cells missing 1 (GCM1) and western blot analysis confirmed GCM1 was expressed in equine chorionic girdle (ChG) and surrounding tissues. Luciferase assays demonstrated endogenous activity of the LHB promoter in BeWo choriocarcinoma cells with greatest activity by a proximal 335 bp promoter fragment. Transactivation studies in COS7 cells using an equine GCM1 expression vector showed GCM1 could transactivate the proximal 335 bp LHB promoter. Chromatin immunoprecipitation using primary ChG trophoblast cells showed GCM1 to preferentially bind to the most proximal GCM1-binding site over site 2. Mutation of site 1 but not site 2 resulted in a loss of endogenous promoter activity in BeWo cells and failure of GCM1 to transactivate the promoter in COS-7 cells. Together, these data show that GCM1 binds to site 1 in the LHB promoter but also requires the upstream segment of the LHB promoter between −119 bp and −335 bp of the translation start codon for activity. GCM1 binding partners, ETV1, ETV7, HOXA13, and PITX1, were found to be differentially expressed in the ChG between days 27 and 34 and are excellent candidates for this role. In conclusion, GCM1 was demonstrated to drive the LHB promoter, through direct binding to a predicted GCM1-binding site, with requirement for another factor(s) to bind the proximal promoter to exert this function. Based on these findings, we hypothesize that ETV7 and HOXA13 act in concert with GCM1 to initiate LHB transcription between days 30 and 31, with ETV1 partnering with GCM1 to maintain transcription

Generative Embedding for Model-Based Classification of fMRI Data

Decoding models, such as those underlying multivariate classification algorithms, have been increasingly used to infer cognitive or clinical brain states from measures of brain activity obtained by functional magnetic resonance imaging (fMRI). The practicality of current classifiers, however, is restricted by two major challenges. First, due to the high data dimensionality and low sample size, algorithms struggle to separate informative from uninformative features, resulting in poor generalization performance. Second, popular discriminative methods such as support vector machines (SVMs) rarely afford mechanistic interpretability. In this paper, we address these issues by proposing a novel generative-embedding approach that incorporates neurobiologically interpretable generative models into discriminative classifiers. Our approach extends previous work on trial-by-trial classification for electrophysiological recordings to subject-by-subject classification for fMRI and offers two key advantages over conventional methods: it may provide more accurate predictions by exploiting discriminative information encoded in ‘hidden’ physiological quantities such as synaptic connection strengths; and it affords mechanistic interpretability of clinical classifications. Here, we introduce generative embedding for fMRI using a combination of dynamic causal models (DCMs) and SVMs. We propose a general procedure of DCM-based generative embedding for subject-wise classification, provide a concrete implementation, and suggest good-practice guidelines for unbiased application of generative embedding in the context of fMRI. We illustrate the utility of our approach by a clinical example in which we classify moderately aphasic patients and healthy controls using a DCM of thalamo-temporal regions during speech processing. Generative embedding achieves a near-perfect balanced classification accuracy of 98% and significantly outperforms conventional activation-based and correlation-based methods. This example demonstrates how disease states can be detected with very high accuracy and, at the same time, be interpreted mechanistically in terms of abnormalities in connectivity. We envisage that future applications of generative embedding may provide crucial advances in dissecting spectrum disorders into physiologically more well-defined subgroups

Modélisation conceptuelle pour les applications géomatiques temps réel

Nowadays, the field of the geoprocessing applications is more and more important and the number of software-tools specialized in the handling of the space-time data witnessed a considerable growth during this last decade. Several methods dedicated to the design of geoprocessing applications have been proposed in the literature. Real time applications are also experiencing great changes and refering to the spatial location. The advent of telecommunications has drawn the attention of taking into account the distribution and allocation information for geoprocessing applications. Telegeoprocessing discipline was born from the alliance of telecommunications and geomatics, characterized by the use of modern positioning systems like GPS (Global Positioning System). Currently, the emergence of pervasive information systems opens several research areas. Thus real time geoprocessing applications raise several problems. In fact, their architecture must support mathematical models and algorithms with important capacities of calculations; besides there is the difficulty to take in account of the real time granularity. They also present major problems at the design stage because of the absence of a specific standardized formalism. The different formalisms that exist in the literature which are supported by design methods of geomatic applications and real time applications are inefficient to answer the problems of design of the real time geoprocessing applications. The research we conducted allowed us to offer basic concepts based on UML (Unified Modeling Language) extensions to take into account the conceptual issues of communication, location data and applications. Thus we propose a UML profile that addresses real time constraints in the field of real time geoprocessing applications. The GRT (Geographic Real Time) profile targets the design of real-time geoprocessing applications. This work has led to a prototype with a CASE (Computer Aided Software Engineering) tool supporting the proposed formalism. A validation through concrete examples enabled us to enrich this prototype.Le domaine des applications géomatiques est en plein essor et le nombre de logiciels spécialisés dans la manipulation des données spatio-temporelles a connu une croissance considérable cette dernière décennie. Cette évolution a été accompagnée, dans la littérature, par la proposition de plusieurs méthodes de conception dédiées aux applications géomatiques. Les applications temps réel connaissent également une grande évolution et font référence à la localisation spatiale. L’avènement des télécommunications a suscité l’intérêt de prendre en compte la distribution et la répartition de l’information pour les applications géomatiques. La discipline de télégéomatique est née d’une fusion de la géomatique et des télécommunications en se caractérisant par l’usage des systèmes modernes de positionnement de type GPS (Global Positionning System). Actuellement, l’émergence des systèmes d’information pervasifs ouvre plusieurs axes de recherche. Ainsi les applications géomatiques temps réel soulèvent plusieurs problématiques : l’architecture logicielle de telles applications doit supporter des modèles mathématiques et des algorithmes qui ont des capacités de calculs importantes, la prise en compte de la granularité du temps réel et la conception et la modélisation de telles applications doit permettre de formaliser les spécifications et d’apporter des outils logiciels cohérents par rapport aux besoins des utilisateurs et des contraintes liées à la réactivité et éventuellement la mobilité des composants du système. Les différents formalismes qui existent dans la littérature et qui sont supportés par des méthodes de conception des applications géomatiques et des applications temps réel sont insuffisants et ne répondent pas au besoin du concepteur. Un travail de recherche dans la prise en compte au niveau conceptuel des contraintes liées à la dimension temps réelle de la nouvelle génération des applications géomatiques temps réel est certainement prometteuse. Les recherches que nous avons menées nous ont permis de proposer des concepts de base s’appuyant sur des extensions d’UML (Unified Modeling Language) afin de prendre en compte au niveau conceptuel les problématiques de communications et de localisation des données et des applications. Nous proposons un profil UML pour la conception des applications géomatiques temps réel. C’est le profil GRT (Geographic Real Time) dédié à la conception des applications géomatiques temps réel. Ce travail débouche sur un prototype doté d’un atelier de génie logiciel supportant le formalisme proposé. Une validation à travers des exemples concrets nous permettra d’enrichir ce prototyp