Colloquium: Mechanical formalisms for tissue dynamics

The understanding of morphogenesis in living organisms has been renewed by tremendous progressin experimental techniques that provide access to cell-scale, quantitative information both on theshapes of cells within tissues and on the genes being expressed. This information suggests that ourunderstanding of the respective contributions of gene expression and mechanics, and of their crucialentanglement, will soon leap forward. Biomechanics increasingly benefits from models, which assistthe design and interpretation of experiments, point out the main ingredients and assumptions, andultimately lead to predictions. The newly accessible local information thus calls for a reflectionon how to select suitable classes of mechanical models. We review both mechanical ingredientssuggested by the current knowledge of tissue behaviour, and modelling methods that can helpgenerate a rheological diagram or a constitutive equation. We distinguish cell scale ("intra-cell")and tissue scale ("inter-cell") contributions. We recall the mathematical framework developpedfor continuum materials and explain how to transform a constitutive equation into a set of partialdifferential equations amenable to numerical resolution. We show that when plastic behaviour isrelevant, the dissipation function formalism appears appropriate to generate constitutive equations;its variational nature facilitates numerical implementation, and we discuss adaptations needed in thecase of large deformations. The present article gathers theoretical methods that can readily enhancethe significance of the data to be extracted from recent or future high throughput biomechanicalexperiments.Comment: 33 pages, 20 figures. This version (26 Sept. 2015) contains a few corrections to the published version, all in Appendix D.2 devoted to large deformation

Episodic Therapy for Genital Herpes in Sub-Saharan Africa: A Pooled Analysis from Three Randomized Controlled Trials

BACKGROUND: A randomized controlled trial in South Africa found a beneficial effect of acyclovir on genital ulcer healing, but no effect was seen in trials in Ghana, Central African Republic and Malawi. The aim of this paper is to assess whether the variation in impact of acyclovir on ulcer healing in these trials can be explained by differences in the characteristics of the study populations. METHODOLOGY/PRINCIPAL FINDINGS: Pooled data were analysed to estimate the impact of acyclovir on the proportion of ulcers healed seven days after randomisation by HIV/CD4 status, ulcer aetiology, size and duration before presentation; and impact on lesional HIV-1. Risk ratios (RR) were estimated using Poisson regression with robust standard errors. Of 1478 patients with genital ulcer, most (63%) had herpetic ulcers (16% first episode HSV-2 ulcers), and a further 3% chancroid, 2% syphilis, 0.7% lymphogranuloma venereum and 31% undetermined aetiology. Over half (58%) of patients were HIV-1 seropositive. The median duration of symptoms before presentation was 6 days. Patients on acyclovir were more likely to have a healed ulcer on day 7 (63% vs 57%, RR = 1.08, 95% CI 0.98-1.18), shorter time to healing (p = 0.04) and less lesional HIV-1 RNA (p = 0.03). Small ulcers (<50 mm(2)), HSV-2 ulcers, first episode HSV-2 ulcers, and ulcers in HIV-1 seropositive individuals responded best but the better effectiveness in South Africa was not explained by differences in these factors. CONCLUSIONS/SIGNIFICANCE: There may be slight benefit in adding acyclovir to syndromic management in settings where most ulcers are genital herpes. The stronger effect among HIV-1 infected individuals suggests that acyclovir may be beneficial for GUD/HIV-1 co-infected patients. The high prevalence in this population highlights that genital ulceration in patients with unknown HIV status provides a potential entry point for provider-initiated HIV testing

Rapid SAR estimation using radiated power measurements

International audienc

Performance of the BioPlex 2200 Multiplexing Immunoassay Platform for the Detection of Herpes Simplex Virus Type 2 Specific Antibodies in African Settings ▿

The BioPlex platform was evaluated for the detection of herpes simplex virus 2 (HSV-2) antibodies in sub-Saharan Africa individuals in comparison to clinicovirological standards and compared to HerpeSelect. The sensitivities and specificities were, respectively, 88.9% and 93.5% for BioPlex and 89.9% and 92.7% for HerpeSelect. The agreement between both assays was 95.7%

Un système intégré de surveillance de la qualité de l'eau des lacs urbains : un outil d'aide à la décision pour la base nautique du Lac de Créteil (France)

In urban lakes, water quality and, in particular phytoplankton blooms, have a significant impact on use and limitaquatic activities. Managers of water bodies are faced with difficulties in decision-making to avoid sanitary risksof users. Lake Créteil (France), located in a highly urbanised catchment, is used for water recreational activities.The lake has been equipped with an autonomous monitoring system, consisting of an instrumented buoy thattakes in situ measurements of temperature, oxygen, conductivity, chlorophyll-a and phycocyanin (a specificcyanobacteria pigment) every 15 minutes. A weather station is installed on the buoy. The measurements aretransmitted to a server on land. A major challenge for the operational use of such a monitoring system is toenable its generality and interoperability. This paper presents the design of an autonomous monitoring systemand the use of an open source software to standardise the data format, archive the data on a local server anddisplay them on a web interface. The data transfer from the local server to the graphical visualisation tool is doneusing the standard SensorThings application programming interface (API) of Open Geospatial Consortium (OGC).The visualisation is based on the FROST software, a web server with its own database. The implementation ofthe SensorThings API (OGC) allows interaction with the visualisation tool (FROST). The time evolution of themeasured variables, plotted on a website allows the lake managers to make decisions in near real time.Dans les lacs urbains, la qualité de l'eau et en particulier les proliférations phytoplanctoniques, ont un impact important sur les usages et limitent les activités récréatives et sportives. Les gestionnaires de plans d'eau sont confrontés à des difficultés de prise de décision lorsqu'il s'agit d'éviter les risques sanitaires des usagers. Le lac de Créteil (France), situé dans un bassin versant fortement urbanisé, est utilisé pour des loisirs aquatiques. Le lac a été équipé d'un système de suivi autonome, constitué d'une bouée instrumentée effectuant des mesures in situ de température, oxygène, conductivité, chlorophylle-a et phycocyanine (pigment spécifique des cyanobactéries), toutes les 15 minutes. La bouée embarque également une station météorologique. Les mesures sont télétransmises vers un serveur à terre. Un défi majeur pour l'utilisation opérationnelle d'un tel système est d'en assurer la généralité et l'interopérabilité. Cet article présente la conception d'un système de surveillance autonome et l'utilisation d'un logiciel open source pour la standardisation du format des données, leur archivage sur un serveur local et la procédure d'affichage sur une interface web. Les données sont transférées du serveur local vers l'outil graphique à l'aide de l'interface de programmation applicative (API) SensorThings de l'Open Geospatial Consortium (OGC SensorThings API). La visualisation s'appuie sur le logiciel FROST, un logiciel de serveur web comprenant sa propre base de données. L'implémentation de l'API SensorThings (OGC) permet d'interagir avec l'outil de visualisation (FROST). La visualisation sur un site Web de l'évolution temporelle des variables mesurées, permet aux gestionnaires du lac une prise de décision en temps réel

Le style de vie et le statut social du curé de Rigny entre le milieu du 15e et la première moitié du 18^e siècle : quelques aperçus

National audienc

Body surface area, erythrocyte sedimentation rate, methotrexate and antibodies to infliximab influence the pharmacokinetics of infliximab in rheumatoid arthritis

International audienc