Global well-posedness of a conservative relaxed cross diffusion system

We prove global existence in time of solutions to relaxed conservative cross diffusion systems governed by nonlinear operators of the form $u_i\to \partial_tu_i-\Delta(a_i(\tilde{u})u_i)$ where the $u_i, i=1,...,I$ represent $I$ density-functions, $\tilde{u}$ is a spatially regularized form of $(u_1,...,u_I)$ and the nonlinearities $a_i$ are merely assumed to be continuous and bounded from below. Existence of global weak solutions is obtained in any space dimension. Solutions are proved to be regular and unique when the $a_i$ are locally Lipschitz continuous

Prediction of subplastidial localization of chloroplast proteins from spectral count data - Comparison of machine learning algorithms

To study chloroplast metabolism and functions, subplastidial localization is a prerequisite to achieve protein functional characterization. As the accurate localization of many chloroplast proteins often remains hypothetical, we set up a proteomics strategy in order to assign the accurate subplastidial localization. A comprehensive study of Arabidopsis thaliana chloroplast proteome has been carried out in our group [1], involving high performance mass spectrometry analyses of highly fractionated chloroplasts. In particular, spectral count data were acquired for the three major chloroplast sub-fractions (stroma, thylakoids and envelope) obtained by sucrose gradient purification. As the distribution of spectral counts over compartments is a fair predicator of relative abundance of proteins [2], it was justified to propose a prime statistical model [1] relating spectral counts to subplastidial localization. This predictive model was based on a logistic regression, and demonstrated an accuracy rate of 84% for chloroplast proteins. In the present work, we conducted a comparative study of various machine learning techniques to generate a predictive model of subplastidial localization of chloroplast proteins based on spectral count data

Atypical antipsychotic therapy in Parkinson's disease psychosis: A retrospective study.

ObjectiveParkinson's disease psychosis (PDP) is a frequent complication of idiopathic Parkinson's disease (iPD) with significant impact on quality of life and association with poorer outcomes. Atypical antipsychotic drugs (APDs) are often used for the treatment of PDP; however, their use is often complicated by adverse drug reactions (ADRs). In this study, we present patients with PDP who were treated with the most commonly used atypical antipsychotic agents and review their respective ADRs.MethodsA retrospective study was carried out to include a total of 45 patients with iPD who visited a movement disorders clinic between 2006 and 2015. All PDP patients treated with atypical APDs were included in the analysis for their specific ADRs.ResultsForty-five iPD patients (mean age of onset: 62.67 ± 9.86 years) were included, of those 10 patients had psychosis (mean age of onset: 76.80 ± 4.61 years). Of the 45 patients, 22.2% were found to have psychotic symptoms, of whom 70% had hallucinations, 20% had delusions, and 10% illusions. Seventy percent of psychotic symptoms occurred after ten or more years from diagnosis of iPD. PDP patients were treated with quetiapine, olanzapine, and risperidone separately or in combination, all of which were found to have certain ADRs.LimitationsThis study was limited by its retrospective study design and small sample size and with likely selection bias.ConclusionsThe prevalence of PDP is relatively high in older patients with iPD. The uses of the currently available atypical APDs in this patient population are often complicated by ADRs. The selective 5-HT 2A inverse agonist, pimavanserin, could be a better alternative in the treatment of PDP

Visualizing Compaction of Polysomes in Bacteria.

International audienceDuring protein synthesis, many translating ribosomes are bound together with an mRNA molecule to form polysomes (or polyribosomes). While the spatial organization of bacterial polysomes has been well studied in vitro, little is known about how they cluster when cellular conditions are highly constrained. To better understand this, we used electron tomography, template matching, and three-dimensional modeling to analyze the supramolecular network of ribosomes after induction of translational pauses. In Escherichia coli, we overexpressed an mRNA carrying a polyproline motif known to induce pausing during translation. When working with a strain lacking transfer-messenger RNA, the principle actor in the "trans-translation" rescuing system, the cells survived the hijacking of the translation machinery but this resulted in a sharp modification of the ribosomal network. The results of our experiments demonstrate that single ribosomes are replaced with large amounts of compacted polysomes. These polysomes are highly organized, principally forming hairpins and dimers of hairpins that stack together. We propose that these spatial arrangements help maintain translation efficiency when the rescue systems are absent or overwhelmed

The splicing co-factor Barricade/Tat-SF1, is required for cell cycle and lineage progression in Drosophila neural stem cells

Stem cells need to balance self-renewal and differentiation for correct tissue development and homeostasis. Defects in this balance can lead to developmental defects or tumor formation. In recent years, mRNA splicing has emerged as one important mechanism regulating cell fate decisions. Here we address the role of the evolutionary conserved splicing co-factor Barricade (Barc)/Tat-SF1/CUS2 in Drosophila neural stem cell (neuroblast) lineage formation. We show that Barc is required for the generation of neurons during Drosophila brain development by ensuring correct neural progenitor proliferation and differentiation. Barc associates with components of the U2 small nuclear ribonucleic proteins (snRNP), and its depletion causes alternative splicing in form of intron retention in a subset of genes. Using bioinformatics analysis and a cell culture based splicing assay, we found that Barc-dependent introns share three major traits: they are short, GC rich and have weak 3' splice sites. Our results show that Barc, together with the U2snRNP, plays an important role in regulating neural stem cell lineage progression during brain development and facilitates correct splicing of a subset of introns

Investigating A Dose Response Relationship between High Fat Diet Consumption and the Contractile Performance of Isolated Mouse Soleus, EDL and Diaphragm Muscles

PurposeRecent evidence has demonstrated an obesity-induced, skeletal muscle-specific reduction in contractile performance. The extent and magnitude of these changes in relation to total dose of high-fat diet consumption remains unclear. This study aimed to examine the dose–response relationship between a high-fat diet and isolated skeletal muscle contractility.Methods120 female CD1 mice were randomly assigned to either control group or groups receiving 2, 4, 8 or 12 weeks of a high-calorie diet (N = 24). At 20 weeks, soleus, EDL or diaphragm muscle was isolated (n = 8 in each case) and isometric force, work loop power output and fatigue resistance were measured.ResultsWhen analysed with respect to feeding duration, there was no effect of diet on the measured parameters prior to 8 weeks of feeding. Compared to controls, 8-week feeding caused a reduction in normalised power of the soleus, and 8- and 12-week feeding caused reduced normalised isometric force, power and fatigue resistance of the EDL. Diaphragm from the 12-week group produced lower normalised power, whereas 8- and 12-week groups produced significantly lower normalised isometric force. Correlation statistics indicated that body fat accumulation and decline in contractility will be specific to the individual and independent of the feeding duration.ConclusionThe data indicate that a high-fat diet causes a decline in muscle quality with specific contractile parameters being affected in each muscle. We also uniquely demonstrate that the amount of fat gain, irrespective of feeding duration, may be the main factor in reducing contractile performance

Modification des propriétés des poudres par enrobage à sec dans un mélangeur Cyclomix

International audienceNous présentons ici une étude de la modification de certaines propriétés de poudres après enrobage de fines particules sur des particules hôtes dans un mélangeur de laboratoire modèle « Cyclomix », d'une contenance de 1 litre. Ce type d'appareil présente des effets de cisaillement et d'impact, permettant de réaliser rapidement des enrobages à sec avec des volumes significatifs de poudre. De plus des possibilités d'extrapolation à des échelles supérieures (jusqu'à 500 L) existent pour préparer des quantités industrielles de poudres à surface modifiée. Plusieurs systèmes particulaires sont utilisés, avec des particules hôtes différentes : des poudres de gel de silice et d'amidon de maïs. Différents types de particules invitées ont été également examinées : stéarate de magnésium, silice hydrophile ou hydrophobe. Les caractéristiques morphologiques des poudres, et les densités du solide (mesurées par pycnomètre à hélium) ont été déterminées. Les modifications apportées aux particules hôtes par les particules invitées sont caractérisées par des tests de cinétique d'adsorption de vapeur d'eau, de mesure d'angle de contact par goutte posée, et d'évaluation de la coulabilité par mesures de densités tassées ou non tassées. Les résultats obtenus montrent que le mélangeur Cyclomix permet de réaliser des enrobages de poudres modifiant les propriétés de façon sensible

Changing practice in dementia care in the community: developing and testing evidence-based interventions, from timely diagnosis to end of life (EVIDEM)

Background Dementia has an enormous impact on the lives of individuals and families, and on health and social services, and this will increase as the population ages. The needs of people with dementia and their carers for information and support are inadequately addressed at all key points in the illness trajectory. Methods The Unit is working specifically on an evaluation of the impact of the Mental Capacity Act 2005, and will develop practice guidance to enhance concordance with the Act. Phase One of the study has involved baseline interviews with practitioners across a wide range of services to establish knowledge and expectations of the Act, and to consider change processes when new policy and legislation are implemented. Findings Phase 1, involving baseline interviews with 115 practitioners, identified variable knowledge and understanding about the principles of the Act. Phase 2 is exploring everyday decision-making by people with memory problems and their carers