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Deletion of PPARα in mouse brown adipocytes increases their De Novo Lipogenesis
No full textInternational audienceObjective: Peroxisome Proliferator-Activated Receptors (PPARs) are nuclear receptors involved in the control of lipid metabolism. The PPARα isoform is highly expressed in brown adipose tissue (BAT). However, its precise role in BAT remains unclear. Here, we aimed to investigate the role of PPARα in BAT of high fat diet-induced obese mice in a thermoneutral environment.Methods: We used tamoxifen-inducible-BAT specific PPARα knockout mice (PPARαBATKO) that were housed at thermoneutrality to minimize BAT basal activation, fed a high-fat diet for 20 weeks and challenged with a β3-adrenergic agonist (CL316,243) during the last week. Both male and female mice were studied.Results: Body weight and glucose tolerance tests were similar in both sexes and genotypes. However, BAT morphology was altered in PPARαBATKO mice, with more unilocular and larger lipid droplets compared to control mice, suggesting BAT impaired function. Indeed, when treated with CL316,243, both male and female mice had increased De Novo Lipogenesis (DNL), reflected by an increased expression of ChREBPβ and lipogenic enzymes ACLY, ACC1, FASN and SCD1. These changes were accompanied by an increase in fatty acids in triglycerides, and thus an increase in lipid storage. Moreover, lipid profiles in phospholipids were different, suggesting a modification in the membrane content with an increase of palmitoleate.Conclusions: Altogether, our results reveal a key role for PPARα in DNL in BAT and in the regulation of lipid metabolism in HFD-induced obesity
Des sépultures multiples témoins d’une crise sanitaire tardo-antique dans la nécropole de Saint-Seurin à Bordeaux
No full textInternational audienceExcavation was carried out in 2016-2017 prior to a building development project on the Rue Abbé de l’Épée in Bordeaux, identifying occupation dating from the Late Antique to the Modern period. The remains identified testify to a continuous but evolving occupation of this marginal district, and shed light on the history of Bordeaux’s urban fabric. The southern half of the excavation area revealed burials from Late Antiquity, corresponding to a previously unexplored sector of the Saint-Seurin necropolis. While some of the burials discovered fit in perfectly as a continuition of the remains already known, the excavation also revealed the presence of a highly unusual group of multiple burials indicative of an unprecedented health crisis.Préalablement au lancement d’un programme immobilier situé rue Castéja à Bordeaux (Gironde), une fouille préventive a été menée en 2016-2017, révélant une occupation allant de l’époque tardo-antique à l’époque moderne. Les vestiges témoignent d’une occupation longue et diverse, éclairant l’évolution urbaine de la ville. Les inhumations de l’Antiquité tardive de la moitié sud de l’emprise de fouille correspondent à un secteur jusqu’alors inexploré de la nécropole de Saint-Seurin. Si une partie d’entre elles s’intègre parfaitement aux vestiges déjà connus, l’intervention a également montré la présence d’un ensemble tout à fait original de sépultures multiples relevant d’une crise sanitaire sans précédent
A systematic review of relation extraction task since the emergence of Transformers
No full textThis article presents a systematic review of relation extraction (RE) research since the advent of Transformer-based models. Using an automated framework to collect and annotate publications, we analyze 34 surveys, 64 datasets, and 104 models published between 2019 and 2024. The review highlights methodological advances, benchmark resources, and the integration of semantic web technologies. By consolidating results across multiple dimensions, the study identifies current trends, limitations, and open challenges, offering researchers and practitioners a comprehensive reference for understanding the evolution and future directions of RE
Détermination du sexe gonadique chez les vertébrés : repenser les mécanismes établis
No full textInternational audienceSex determination and differentiation are fundamental processes that are not only essential for fertility but also influence the development of many other organs, and hence, are important for species diversity and survival. In mammals, sex is determined by the inheritance of an X or a Y chromosome from the father. The Y chromosome harbours the testis-determining gene SRY, and it has long been thought that its absence is sufficient for ovarian development. Consequently, the ovarian pathway has been treated as a default pathway, in the sense that ovaries do not have or need a female-determining factor. Recently, a female-determining factor has been identified in mouse as the master regulator of ovarian development. Interestingly, this scenario was predicted as early as 1983. In this Review, we discuss the model predicted in 1983, how the mechanisms and genes currently known to be important for sex determination and differentiation in mammals have changed or supported this model, and finally, reflect on what these findings might mean for sex determination in other vertebrates
Inertial Bregman Proximal Gradient under Partial Smoothness
No full textThis work considers an Inertial version of Bregman Proximal Gradient algorithm (IBPG) for minimizing the sum of two single-valued functions in finite dimension. We suppose that one of the functions is proper, closed, and convex but non-necessarily smooth whilst the second is a smooth enough function but not necessarily convex. For the latter, we ask the smooth adaptable property (smad) with respect to some kernel or entropy which allows to remove the very popular global Lipschitz continuity requirement on the gradient of the smooth part. We consider the IBPG under the framework of the triangle scaling property (TSP) which is a geometrical property for which one can provably ensure acceleration for a certain subset of kernel/entropy functions in the convex setting. Based on this property, we provide global convergence guarantees when the entropy is strongly convex under the framework of the Kurdyka-Łojasiewicz (KL) property. Turning to the local convergence properties, we show that when the nonsmooth part is partly smooth relative to a smooth submanifold, IBPG has a finite activity identification property before entering a local linear convergence regime for which we establish a sharp estimate of the convergence rate. We report numerical simulations to illustrate our theoretical results on low complexity regularized phase retrieval
Brillouin-Random Laser and Fiber Bragg Gratings for All-Fiber High-Resolution Sensing
No full textInternational audienceThis letter presents the development of a high-resolution all-fiber strain sensing system using a narrow linewidth Brillouin-random laser (BRL)in conjunction with a fiber Bragg grating (FBG). The so-called BRL-FBG sensor system is based on a Brillouin fiber laser with a linewidth nar-rowed by a random laser obtained with a nanoparticle (NP) doped optical fiber, especially manufactured for a higher Rayleigh scattering. The BRLresults indicated a 74.68% reduction of the laser linewidth when the NP-doped fiber is used. Furthermore, the laser presented a power stability of92.36%. Then, the BRL signal is fed to an FBG, subjected to small axial strain variation and the convolution between both signals result in the reflected optical power variations as a function applied strain, where a 0.05μ strain sensing resolution is obtained. Thus, the proposed system can be em-ployed on the high-resolution sensing of different physical parameters with potentially high acquisition frequency
Label-free multiplexed detection of diabetic retinopathy biomarkers using fiber optic biosensors: Towards lab-in-the-tear
No full textInternational audienceDiabetic retinopathy is a common disease in diabetic patients accompanied by such complications as edema, formation of hard exudates, hemorrhages, and eventually vision loss. Detection of the disease at an early stage could increase the effectiveness of therapy and preserve the patient’s vision. Measuring the levels of diabetic retinopathy-associated biomarkers using more reliable methods is an alternative and promising way of diagnosis. Optical fiber biosensors have gained rising popularity in providing affordable platforms due to their high-performance capabilities, miniature size, and label-free nature of detection. These properties made them a sensor of choice for developing biosensors for a multiplexed in situ detection of biomarkers in this study. Here, we report an optical fiber-based biosensor that is based on simply fabricated semi-distributed interferometry sensors. After fabrication, sensitive sensors were chosen for further functionalization with two antibodies against biomarkers relevant to diabetic retinopathy to produce biosensors. The detection of the biomarkers was evaluated in artificial tear fluid in static conditions and most importantly in dynamic conditions simulating natural tear flow. This method allowed label-free monitoring of the intensity change with the increasing concentrations of analytes specifically binding on the biosensor surface. Namely, it was possible to detect lipocalin 1 protein with a limit of detection of 5.98 ng/mL and vascular endothelial growth factor down to 26.6 fg/mL. The designed biosensors can become the basis for developing a new method for a clinical diagnosis of eye diseases at early stages of development
Eigengap Sparsity for Covariance Parsimony
No full textInternational audienceCovariance estimation is a central problem in statistics. An important issue is that there are rarely enough samples n to accurately estimate the p (p+1) / 2 coefficients in dimension p. Parsimonious covariance models are therefore preferred, but the discrete nature of model selection makes inference computationally challenging. In this paper, we propose a relaxation of covariance parsimony termed "eigengap sparsity" and motivated by the good accuracy-parsimony tradeoffs of eigenvalue-equalization in covariance matrices. This penalty can be included in a penalized-likelihood framework that we propose to solve with a projected gradient descent on a monotone cone. The algorithm turns out to resemble an isotonic regression of mutually-attracted sample eigenvalues, drawing an interesting link between covariance parsimony and shrinkage
A step-by-step protocol based on data mining to explore purinergic signaling in glioblastoma
No full textInternational audienceOver the past few years, transcriptomics has emerged as a pillar for modern scientific research, enabling the comprehensive profiling of gene expression. The availability of large-scale public datasets, such as NCBI Gene Expression Omnibus, International Cancer Genome Consortium, and The Cancer Genome Atlas, has significantly boosted many scientific discoveries. However, to analyse and interpret these vast datasets, sophisticated bioinformatic tools are often necessary. Phantasus is a user-friendly web application designed to streamline gene expression analysis. By integrating data loading, normalization, filtering, enrichment pathways analysis, and PrincipalComponent Analysis, Phantasus enables researchers to promptly investigate and evaluate complex gene expression patterns. This tool simplifies the identification of differentially expressed genes and the discovery of novel biological insights. Here, we demonstrate how Phantasus can be utilized for gene expression analysis in glioblastoma (GBM), the most common primary malignant brain tumor in adults. Specifically, we focus on the role of purinergic signaling, with particular emphasis on the P2RX7 mRNA coding for the P2X7 receptor (P2X7R). To illustrate our proposal, we analyzed the expression of genes related to purinergic signaling in GBM patients stratified by high and low levels of P2RX7 expression.By harnessing Phantasus, researchers can further explore and navigate the nuances of gene regulation and its impact on human health and diseases.</div