A three-dimensional Hellinger-Reissner Virtual Element Method for linear elasticity problems

We present a Virtual Element Method for the 3D linear elasticity problems, based on Hellinger-Reissner variational principle. In the framework of the small strain theory, we propose a low-order scheme with a-priori symmetric stresses and continuous tractions across element interfaces. A convergence and stability analysis is developed and we confirm the theoretical predictions via some numerical tests.Comment: submitted to CMAM

Exploring the role of fallopian ciliated cells in the pathogenesis of high-grade serous ovarian cancer

High-grade serous epithelial ovarian cancer (HGSOC) is the fifth leading cause of cancer death in women and the first among gynecological malignancies. Despite an initial response to standard chemotherapy, most HGSOC patients relapse. To improve treatment options, we must continue investigating tumor biology. Tumor characteristics (e.g., risk factors and epidemiology) are valuable clues to accomplish this task. The two most frequent risk factors for HGSOC are the lifetime number of ovulations, which is associated with increased oxidative stress in the pelvic area caused by ovulation fluid, and a positive family history due to genetic factors. In the attempt to identify novel genetic factors (i.e., genes) associated with HGSOC, we observed that several genes in linkage with HGSOC are expressed in the ciliated cells of the fallopian tube. This finding made us hypothesize that ciliated cells, despite not being the cell of origin for HGSOC, may take part in HGSOC tumor initiation. Specifically, malfunction of the ciliary beat impairs the laminar fluid flow above the fallopian tube epithelia, thus likely reducing the clearance of oxidative stress caused by follicular fluid. Herein, we review the up-to-date findings dealing with HGSOC predisposition with the hypothesis that fallopian ciliated cells take part in HGSOC onset. Finally, we review the up-to-date literature concerning genes that are located in genomic loci associated with epithelial ovarian cancer (EOC) predisposition that are expressed by the fallopian ciliated cells

Amélioration des performances du système numérique de Radio Mondiale à l'aide de constellations non-uniformes

Appui à la mise en place d'un Master professionnalisant en photonique et en radiodiffusion numérique - PHORAN - Fédération Wallonie Bruxelle

Digestibilidade de dietas com diferentes formas físicas para frangos de corte.

A peletização é o processamento térmico mais utilizado na indústria avícola, pois favorece o aproveitamento dos ingredientes e modifica a forma física da dieta. A pressão, umidade e temperatura empregadas por determinado tempo no processo, promovem alterações nas estruturas dos carboidratos, bem como das proteínas. O objetivo desse estudo foi avaliar o efeito de diferentes formas físicas (farelada ou peletizada/triturada com diferentes tempos de condicionamento) sobre o coeficiente de digestibilidade ileal aparente da matéria seca (CDIAMS), proteína bruta (CDIAPB) e energia digestível ileal (EDI) em frangos de corte de 1 a 25 dias

Human dyskerin binds to cytoplasmic H/ACA-box-containing transcripts affecting nuclear hormone receptor dependence

Background Dyskerin is a nuclear protein involved in H/ACA box snoRNA-guided uridine modification of RNA. In humans, its defective function is associated with cancer development and induces specific post-transcriptional alterations of gene expression. In this study, we seek to unbiasedly identify mRNAs regulated by dyskerin in human breast cancer-derived cells. Results We find that dyskerin depletion affects the expression and the association with polysomes of selected mRNA isoforms characterized by the retention of H/ACA box snoRNA-containing introns. These snoRNA retaining transcripts (snoRTs) are bound by dyskerin in the cytoplasm in the form of shorter 3 ' snoRT fragments. We then characterize the whole cytoplasmic dyskerin RNA interactome and find both H/ACA box snoRTs and protein-coding transcripts which may be targeted by the snoRTs' guide properties. Since a fraction of these protein-coding transcripts is involved in the nuclear hormone receptor binding, we test to see if this specific activity is affected by dyskerin. Obtained results indicate that dyskerin dysregulation may alter the dependence on nuclear hormone receptor ligands in breast cancer cells. These results are paralleled by consistent observations on the outcome of primary breast cancer patients stratified according to their tumor hormonal status. Accordingly, experiments in nude mice show that the reduction of dyskerin levels in estrogen-dependent cells favors xenograft development in the absence of estrogen supplementation. Conclusions Our work suggests a cytoplasmic function for dyskerin which could affect mRNA post-transcriptional networks relevant for nuclear hormone receptor functions

Purified autologous grafting in childhood acute lymphoblastic leukemia in second remission: evidence for long-term clinical and molecular remissions

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CAG repeat expansion in the Huntington’s disease gene shapes linear and circular RNAs biogenesis

Alternative splicing (AS) appears to be altered in Huntington’s disease (HD), but its significance for early, pre-symptomatic disease stages has not been inspected. Here, taking advantage of Htt CAG knock-in mouse in vitro and in vivo models, we demonstrate a correlation between Htt CAG repeat length and increased aberrant linear AS, specifically affecting neural progenitors and, in vivo, the striatum prior to overt behavioral phenotypes stages. Remarkably, a significant proportion (36%) of the aberrantly spliced isoforms are not-functional and meant to non-sense mediated decay (NMD). The expanded Htt CAG repeats further reflect on a previously neglected, global impairment of back-splicing, leading to decreased circular RNAs production in neural progenitors. Integrative transcriptomic analyses unveil a network of transcriptionally altered micro-RNAs and RNA-binding proteins (CELF, hnRNPS, PTBP, SRSF, UPF1, YTHD2) which might influence the AS machinery, primarily in neural cells. We suggest that this unbalanced expression of linear and circular RNAs might alter neural fitness, contributing to HD pathogenesis

Hyper conserved elements in vertebrate mRNA 3’-UTRs reveal a translational network of RNA-binding proteins controlled by HUR

Little is known regarding the post-transcriptional networks that control gene expression in eukaryotes. Additionally, we still need to understand how these networks evolve, and the relative role played in them by their sequence-dependent regulatory factors, non-coding RNAs (ncRNAs) and RNA-binding proteins (RBPs). Here, we used an approach that relied on both phylogenetic sequence sharing and conservation in the whole mapped 30-untranslated regions (30-UTRs) of vertebrate species to gain knowledge on core post-transcriptional networks. The identified human hyper conserved elements (HCEs) were predicted to be preferred binding sites for RBPs and not for ncRNAs, namely microRNAs and long ncRNAs. We found that the HCE map identified a well-known network that post-transcriptionally regulates histone mRNAs. We were then able to discover and experimentally confirm a translational network composed of RNA Recognition Motif (RRM)-type RBP mRNAs that are positively controlled by HuR, another RRM-type RBP. HuR shows a preference for these RBP mRNAs bound in stem\u2013loop motifs, confirming its role as a \u2018regulator of regulators\u2019. Analysis of the transcriptome-wide HCE distribution revealed a profile of prevalently small clusters separated by unconserved intercluster RNA stretches, which predicts the formation of discrete small ribonucleoprotein complexes in the 30-UTRs