55 research outputs found
Functional contribution of the mesencephalic locomotor region to locomotion
Parce qu'il est naturel et facile de marcher, il peut sembler que cet acte soit produit aussi facilement qu'il est accompli. Au contraire, la locomotion nĂ©cessite une interaction neurale complexe entre les neurones supraspinaux, spinaux et pĂ©riphĂ©riques pour obtenir une locomotion fluide et adaptĂ©e Ă l'environnement. La rĂ©gion locomotrice mĂ©sencĂ©phalique (MLR) est un centre locomoteur supraspinal situĂ© dans le tronc cĂ©rĂ©bral qui a notamment pour rĂŽle d'initier la locomotion et d'induire une transition entre les allures locomotrices. Cependant, bien que cette rĂ©gion ait initialement Ă©tĂ© identifiĂ©e comme le noyau cunĂ©iforme (CnF), un groupe de neurones glutamatergiques, et le noyau pĂ©donculopontin (PPN), un groupe de neurones glutamatergiques et cholinergiques, son corrĂ©lat anatomique est encore un sujet de dĂ©bat. Et alors qu'il a Ă©tĂ© prouvĂ© que, que ce soit lors dâune stimulation de la MLR ou pour augmenter la vitesse locomotrice, la plupart des quadrupĂšdes prĂ©sentent un large Ă©ventail d'allures locomotrices allant de la marche, au trot, jusquâau galop, la gamme exacte des allures locomotrices chez la souris est encore inconnue. Ici, en utilisant l'analyse cinĂ©matique, nous avons d'abord dĂ©cidĂ© d'identifier dâĂ©valuer les allures locomotrices des souris C57BL / 6. Sur la base de la symĂ©trie de la dĂ©marche et du couplage inter-membres, nous avons identifiĂ© et caractĂ©risĂ© 8 allures utilisĂ©es Ă travers un continuum de frĂ©quences locomotrices allant de la marche au trot puis galopant avec diffĂ©rents sous-types d'allures allant du plus lent au plus rapide. Certaines allures sont apparues comme attractrices dâautres sont apparues comme transitionnelles. En utilisant une analyse graphique, nous avons Ă©galement dĂ©montrĂ© que les transitions entre les allures n'Ă©taient pas alĂ©atoires mais entiĂšrement prĂ©visibles. Nous avons ensuite dĂ©cidĂ© d'analyser et de caractĂ©riser les contributions fonctionnelles des populations neuronales de CnF et PPN au contrĂŽle locomoteur. En utilisant des souris transgĂ©niques exprimant une opsine rĂ©pondant Ă la lumiĂšre dans les neurones glutamatergiques (Glut) ou cholinergiques (CHAT), nous avons photostimulĂ© (ou photo-inhibĂ©) les neurones glutamatergiques du CnF ou du PPN ou les neurones cholinergiques du PPN. Nous avons dĂ©couvert que les neurones glutamatergiques du CnF initient et modulent lâallure locomotrice et accĂ©lĂšrent le rythme, tandis que les neurones glutamatergiques et cholinergiques du PPN le ralentissent. En initiant, modulant et en accĂ©lĂ©rant la locomotion, notre Ă©tude identifie et caractĂ©rise des populations neuronales distinctes de la MLR. DĂ©finir et dĂ©crire en profondeur la MLR semble dâautant plus urgent quâelle est devenue rĂ©cemment une cible pour traiter les symptĂŽmes survenant aprĂšs une lĂ©sion de la moelle Ă©piniĂšre ou liĂ©s Ă la maladie de Parkinson.Because it is natural and easy to walk, it could seem that this act is produced as easily as it is accomplished. On the contrary, locomotion requires an intricate and complex neural interaction between the supraspinal, spinal and peripheric neurons to obtain a locomotion that is smooth and adapted to the environment. The Mesencephalic Locomotor Region (MLR) is a supraspinal brainstem locomotor center that has the particular role of initiating locomotion and inducing a transition between locomotor gaits. However, although this region was initially identified as the cuneiform nucleus (CnF), a cluster of glutamatergic neurons, and the pedunculopontine nucleus (PPN), a cluster of glutamatergic and cholinergic neurons, its anatomical correlate is still a matter of debate. And while it is proven that, either under MLR stimulation or in order to increase locomotor speed, most quadrupeds exhibit a wide range of locomotor gaits from walk, to trot, to gallop, the exact range of locomotor gaits in the mouse is still unknown. Here, using kinematic analysis we first decided to identify to assess locomotor gaits C57BL/6 mice. Based on the symmetry of the gait and the inter-limb coupling, we identified and characterized 8 gaits during locomotion displayed through a continuum of locomotor frequencies, ranging from walk to trot and then to gallop with various sub-types of gaits at the slowest and highest speeds that appeared as attractors or transitional gaits. Using graph analysis, we also demonstrated that transitions between gaits were not random but entirely predictable. Then we decided to analyze and characterize the functional contributions of the CnF and PPNâs neuronal populations to locomotor control. Using transgenic mice expressing opsin in either glutamatergic (Glut) or cholinergic (CHAT) neurons, we photostimulated (or photoinhibited) glutamatergic neurons of the CnF or PPN or cholinergic neurons of the PPN. We discovered that glutamatergic CnF neurons initiate and modulate the locomotor pattern, and accelerate the rhythm, while glutamatergic and cholinergic PPN neurons decelerate it. By initiating, modulating, and accelerating locomotion, our study identifies and characterizes distinct neuronal populations of the MLR. Describing and defining thoroughly the MLR seems all the more urgent since it has recently become a target for spinal cord injury and Parkinsonâs disease treatment
A Network Integration Approach to Predict Conserved Regulators Related to Pathogenicity of Influenza and SARS-CoV Respiratory Viruses
Respiratory infections stemming from influenza viruses and the Severe Acute Respiratory Syndrome corona virus (SARS-CoV) represent a serious public health threat as emerging pandemics. Despite efforts to identify the critical interactions of these viruses with host machinery, the key regulatory events that lead to disease pathology remain poorly targeted with therapeutics. Here we implement an integrated network interrogation approach, in which proteome and transcriptome datasets from infection of both viruses in human lung epithelial cells are utilized to predict regulatory genes involved in the host response. We take advantage of a novel "crowd-based" approach to identify and combine ranking metrics that isolate genes/proteins likely related to the pathogenicity of SARS-CoV and influenza virus. Subsequently, a multivariate regression model is used to compare predicted lung epithelial regulatory influences with data derived from other respiratory virus infection models. We predicted a small set of regulatory factors with conserved behavior for consideration as important components of viral pathogenesis that might also serve as therapeutic targets for intervention. Our results demonstrate the utility of integrating diverse 'omic datasets to predict and prioritize regulatory features conserved across multiple pathogen infection models
Annotation of long non-coding RNAs expressed in Collaborative Cross founder mice in response to respiratory virus infection reveals a new class of interferon-stimulated transcripts
The outcome of respiratory virus infection is determined by a complex interplay of viral and host factors. Some potentially important host factors for the antiviral response, whose functions remain largely unexplored, are long non-coding RNAs (lncRNAs). Here we systematically inferred the regulatory functions of host lncRNAs in response to influenza A virus and severe acute respiratory syndrome coronavirus (SARS-CoV) based on their similarity in expression with genes of known function. We performed total RNA-Seq on viral-infected lungs from eight mouse strains, yielding a large data set of transcriptional responses. Overall 5,329 lncRNAs were differentially expressed after infection. Most of the lncRNAs were co-expressed with coding genes in modules enriched in genes associated with lung homeostasis pathways or immune response processes. Each lncRNA was further individually annotated using a rank-based method, enabling us to associate 5,295 lncRNAs to at least one gene set and to predict their potential cis effects. We validated the lncRNAs predicted to be interferon-stimulated by profiling mouse responses after interferon-α treatment. Altogether, these results provide a broad categorization of potential lncRNA functions and identify subsets of lncRNAs with likely key roles in respiratory virus pathogenesis. These data are fully accessible through the MOuse NOn-Code Lung interactive database (MONOCLdb)
Whispering to the Deaf: Communication by a Frog without External Vocal Sac or Tympanum in Noisy Environments
Atelopus franciscus is a diurnal bufonid frog that lives in South-American tropical rain forests. As in many other frogs, males produce calls to defend their territories and attract females. However, this species is a so-called âearlessâ frog lacking an external tympanum and is thus anatomically deaf. Moreover, A. franciscus has no external vocal sac and lives in a sound constraining environment along river banks where it competes with other calling frogs. Despite these constraints, male A. franciscus reply acoustically to the calls of conspecifics in the field. To resolve this apparent paradox, we studied the vocal apparatus and middle-ear, analysed signal content of the calls, examined sound and signal content propagation in its natural habitat, and performed playback experiments. We show that A. franciscus males can produce only low intensity calls that propagate a short distance (<8 m) as a result of the lack of an external vocal sac. The species-specific coding of the signal is based on the pulse duration, providing a simple coding that is efficient as it allows discrimination from calls of sympatric frogs. Moreover, the signal is redundant and consequently adapted to noisy environments. As such a coding system can be efficient only at short-range, territory holders established themselves at short distances from each other. Finally, we show that the middle-ear of A. franciscus does not present any particular adaptations to compensate for the lack of an external tympanum, suggesting the existence of extra-tympanic pathways for sound propagation
La filiacion y la fecundacion "in vitro"
Las tecnicas de reproduccion asistida no solo representan una solucion para ayudar a superar problemas de esterilidad, sino que su practica conlleva problemas eticos y juridicos. Esta Tesis analiza los problemas que plantea la fecundacion "in vitro", desde el punto de vista de la filiacion, para determinar la paternidad y maternidad cuando se utilizan los gametos de la pareja o de un tercero. Desde este punto de vista, se estudian la situacion juridica del tercero -llamado donante- y de las madres subrogadas, asi como las acciones de filiacion Tambien se examina la problematica que plantea la congelacion de semen y embriones, al poder un hombre engendrar un hijo despues de muerto. Entre las fuentes que se analizan estan los principales informes extranjeros que han estudiado la problematica de estas tecnicas, asi como el Informe especial de..
Croyances, médecine et art dentaire en Egypte ancienne
REIMS-BU Santé (514542104) / SudocPARIS-BIUM (751062103) / SudocLILLE2-UFR Odontologie (593502202) / SudocSudocFranceF
Le dépÎt funéraire de Lavau (Aube, France) : Une nouvelle évocation du banquet chez les élites celtiques du VÚme siÚcle
International audienc
Le vin et le pouvoir. La tombe princiĂšre de Lavau (Ve siĂšcle avant notre Ăšre)
La tombe princiĂšre de Lavau, dans lâAube, fouillĂ©e par lâInrap en 2014-2015, contenait un riche dĂ©pĂŽt de vaisselle dâorigines variĂ©es (GrĂšce, Ătrurie, productions locales). Lâemploi conjuguĂ© de vaisselle prĂ©cieuse et/ou dâimportation, leur mise en scĂšne Ă©quivoque comme leur utilisation pour la consommation dâun mĂ©lange Ă base de vin rouge et la signification de certains dĂ©cors permettent dâesquisser les liens unissant lâexercice du pouvoir Ă la pratique du banquet. En filigrane, ces objets, leur agencement et leur contenu tĂ©moignent dâun certain degrĂ© dâacculturation de lâĂ©lite celtique envers les pratiques mĂ©diterranĂ©ennes.The princely tomb of Lavau, in the Aube department, excavated by Inrap in 2014-2015, contained a rich deposit of crockery of varied origins (Greece, Etruria, local production). The combined use of precious and/or imported crockery, their equivocal presentation, such as their use for the consumption of a red wine-based mixture, and the significance of certain decorations make it possible to outline the links between the exercise of power and the practice of banqueting. In a subtle way, these objects, their arrangement and their contents testify to a certain degree of acculturation of the Celtic elite towards Mediterranean practices.La tumba principesca de Lavau, en el departamento del Aube, excavada por Inrap en 2014-2015, contenĂa un rico depĂłsito de vajilla de variada procedencia (Grecia, Etruria, producciĂłn local). El uso combinado de vajillas preciosas y/o importadas, su presentaciĂłn equĂvoca, como su utilizaciĂłn para el consumo de una mezcla a base de vino tinto, y la importancia de ciertas decoraciones permiten esbozar los vĂnculos entre el ejercicio del poder y la prĂĄctica del banquete. De manera sutil, estos objetos, su disposiciĂłn y su contenido dan testimonio de un cierto grado de aculturaciĂłn de la Ă©lite celta hacia las prĂĄcticas mediterrĂĄneas
Measurement of wave slope asymmetry from a Multistatic Space Lidar Constellation: Theory and preliminary analysis of Wind direction Retrievals
International audienceRecently, the National Ocean Partnership Program funded the phase A of a lidar cubesat mission: Rainbow. This mission aims to provide information about surface height, surface vector winds, sea-ice, coastal land surface and liquid water clouds. Depending on the final system characteristics, it could also contribute to our knowledge of coastal ocean turbidity and ecology. We propose here to focus on the wind vector retrieval. Wind is a major source of momentum to the upper ocean and modulates the coupling between the atmosphere and the ocean. In littoral areas, wind influences economic activities like ship navigation and fisheries. The Lidar can provide a retrieval of wind properties closer to the coastlines and at a finer scale than typical microwave systems. We will present the theoretical basis of how the lidar can retrieve the wind speed through the surface roughness measurement [1] and wind direction from the multistatic measurement of the wave slope asymmetry. It is well known that the upwind and crosswind components of the mean square slope are drastically different [2] and several lidar receivers looking at the laser light coming from different directions will be sensitive to this asymmetry. The CALIPSO lidar mission has conducted several large off-nadir angle maneuvers (10° to 30° off-nadir) that show this signature of wind direction but with a limited ability for retrieval because it's a single monostatic system. We will present a preliminary analysis of these data and an overview of the features of the Rainbow mission that will allow us to retrieve wind vector from a cubesat lidar constellation
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