The case for absolute ligand discrimination : modeling information processing and decision by immune T cells

Some cells have to take decision based on the quality of surroundings ligands, almost irrespective of their quantity, a problem we name "absolute discrimination". An example of absolute discrimination is recognition of not-self by immune T Cells. We show how the problem of absolute discrimination can be solved by a process called "adaptive sorting". We review several implementations of adaptive sorting, as well as its generic properties such as antagonism. We show how kinetic proofreading with negative feedback implements an approximate version of adaptive sorting in the immune context. Finally, we revisit the decision problem at the cell population level, showing how phenotypic variability and feedbacks between population and single cells are crucial for proper decision

Property FW and wreath products of groups: a simple approach using Schreier graphs

The group property FW stands in-between the celebrated Kazdhan's property (T) and Serre's property FA. Among many characterizations, it might be defined using the number of ends of Schreier graphs. Using this, we show that a finitely generated wreath product $G\wr_XH$ has property FW if and only if both $G$ and $H$ have property FW and $X$ is finite.Comment: v2: corrected the proof of lemma 2.5; results are unchanged. 10 pages, 5 figures. Comments are welcom

Les mises en vue de l'espace public : les formes sensibles de l'espace public

Plan Urbain "Les formes sensibles de l'espace public" n° 23L'approche proposée tente d'articuler les dispositifs technico-spatiaux de l'espace public aux compétences socio-esthétiques du citadin et cherche à dégager des catégories d'analyse de l'espace construit, ici dans le registre visuel et lumineux, (sous l'angle des "mises en vue" qu'il engendre). Sommaire : L'espace public vu des concepteurs - La perception des formes de l'espace urbain public - Les modalités du regard, l'espace public comme paysage - La vision de l'espace urbain sous influences - L'espace public électrique - Illusion, impression et effet Les visibilités sociales du public : des descriptions aux métaphores visuelles Esquisse d'un répertoire des effets visuels et lumineux dans l'environnement urbai

Une lave torrentielle dans la perspective de restauration des terrains de montagne au XIXe siècle (Glandage, Haut-Diois oriental)

Les glissements de terrain et les laves torrentielles sont des aléas importants et récurrents dans les Alpes françaises du Sud. Les laves torrentielles ne sont pas un processus actuellement fonctionnel dans le Diois, mais on est en droit de supposer qu'il le fut au XIXe siècle, en particulier dans les bassins du Haut Diois oriental. Pour tester cette hypothèse, une étude a été réalisée sur le bassin versant du ruisseau de Grimone, un sous-affluent de la Drôme localisé dans la commune de Glandage

Personalized Posture and Fall Classification with Shallow Gated Recurrent Units

Link to final publication : https://ieeexplore.ieee.org/document/8787455International audienceActivities of Daily Living (ADL) classification is a key part of assisted living systems as it can be used to assess a person autonomy. We present in this paper an activity classification pipeline using Gated Recurrent Units (GRU) and inertial sequences. We aim to take advantage of the feature extraction properties of neural networks to free ourselves from defining rules or manually choosing features. We also investigate the advantages of resampling input sequences and personalizing GRU models to improve the performances. We evaluate our models on two datasets: a dataset containing five common postures: sitting, lying, standing, walking and transfer and a dataset named MobiAct V2 providing ADL and falls. Results show that the proposed approach could benefit eHealth services and particularly activity monitoring

Predicting Answering Behaviour in Online Question Answering Communities

The value of Question Answering (Q&A) communities is de- pendent on members of the community finding the questions they are most willing and able to answer. This can be diffi- cult in communities with a high volume of questions. Much previous has work attempted to address this problem by recommending questions similar to those already answered. However, this approach disregards the question selection behaviour of the answers and how it is affected by factors such as question recency and reputation. In this paper, we identify the parameters that correlate with such a behaviour by analysing the users’ answering patterns in a Q&A com- munity. We then generate a model to predict which question a user is most likely to answer next. We train Learning to Rank (LTR) models to predict question selections using various user, question and thread feature sets. We show that answering behaviour can be predicted with a high level of success, and highlight the particular features that influence users’ question selections

Piecewise Affine Registration of Biological Images for Volume Reconstruction

This manuscript tackles the reconstruction of 3D volumes via mono-modal registration of series of 2D biological images (histological sections, autoradiographs, cryosections, etc.). The process of acquiring these images typically induces composite transformations that we model as a number of rigid or affine local transformations embedded in an elastic one. We propose a registration approach closely derived from this model. Given a pair of input images, we first compute a dense similarity field between them with a block matching algorithm. We use as a similarity measure an extension of the classical correlation coefficient that improves the consistency of the field. A hierarchical clustering algorithm then automatically partitions the field into a number of classes from which we extract independent pairs of sub-images. Our clustering algorithm relies on the Earth mover’s distribution metric and is additionally guided by robust least-square estimation of the transformations associated with each cluster. Finally, the pairs of sub-images are, independently, affinely registered and a hybrid affine/non-linear interpolation scheme is used to compose the output registered image. We investigate the behavior of our approach on several batches of histological data and discuss its sensitivity to parameters and noise

Comparative effectiveness of cardioprotective drugs in elderly individuals with type 2 diabetes.

Aims: Although many elderly individuals suffer from type 2 diabetes, the effectiveness of cardioprotective drugs in primary prevention of cardiovascular events in clinical practice in this population has rarely been evaluated. We aimed to assess the effectiveness of, (i) angiotensin converting enzyme inhibitors or angiotensin receptor blockers, (ii) statins, (iii) antiplatelet drugs and (iv) the combination of these three drugs, in the prevention of myocardial infarction (MI) and stroke in elderly individuals with type 2 diabetes. Methods: Using Quebec administrative databases, we conducted nested case-control analyses among a cohort of 17,384 individuals without a history of cardiovascular disease. Individuals were aged ≥ 66 years, newly treated with oral antidiabetes drugs and had not used any of the three above classes of cardioprotective drugs in the year before cohort entry. For each case (MI/stroke during follow-up), five controls were matched for age, year of cohort entry and sex. Use of each drug and of their combination was defined as current, past or no use. We calculated adjusted odds ratios (AOR) of MI/stroke. Results: We observed no reduction in the MI/stroke risk for users of ACEI/ARB nor for users of the three drugs combination. Longer exposure to statins was associated with a lower risk (AOR for every 30 days of therapy: 0.97; 95% CI: 0.96–0.99). By contrast, current use of antiplatelet drugs was associated with an increased risk of MI/stroke (1.40; 1.12–1.75). Conclusion: The benefit of cardioprotective drugs in primary prevention was not clear in this cohort of elderly individuals with type 2 diabetes. A short duration of exposure to these drugs might explain the lack of benefit

Excitonic coupling dominates the homogeneous photoluminescence excitation linewidth in semicrystalline polymeric semiconductors

We measure the homogeneous excitation linewidth of regioregular poly(3-hexylthiophene), a model semicrystalline polymeric semiconductor, by means of two-dimensional coherent photoluminescence excitation spectroscopy. At a temperature of 8\,K, we find a linewidth that is always $\gtrsim 110$\,meV full-width-at-half-maximum, which is a significant fraction of the total linewidth. It displays a spectral dependence and is minimum near the 0--0 origin peak. We interpret this spectral dependence of the homogeneous excitation linewidth within the context of a weakly coupled aggregate model.Comment: 13 pages, 4 figures, Supplementary Materia

Molecular models of human P-glycoprotein in two different catalytic states

P-glycoprotein belongs to the family of ATP-binding cassette proteins which hydrolyze ATP to catalyse the translocation of their substrates through membranes. This protein extrudes a large range of components out of cells, especially therapeutic agents causing a phenomenon known as multidrug resistance. Because of its clinical interest, its activity and transport function have been largely characterized by various biochemical studies. In the absence of a high-resolution structure of P-glycoprotein, homology modeling is a useful tool to help interpretation of experimental data and potentially guide experimental studies.Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe