High-Performance Interactive Scientific Visualization With Datoviz via the Vulkan Low-Level GPU API

We reported initial work towards a new fast and scalable scientific visualization technology that leverages the Vulkan API to achieve unprecedented performance through GPUs. This technology is implemented in a C/C++ library called Datoviz that offers an intermediate-level API for scientific visualization libraries and software. Datoviz provides a unified graphics stack for 2-D, 3-D, graphical user interfaces, and natively supports efficient interactions between rendering and general-purpose GPU computing. A major direction of development is to investigate the integration of Datoviz as a low-level backend of a future version of VisPy, a popular Python scientific plotting librar

Experimental study of concrete cylinders confined by composite materials

Existen numerosas situaciones en las que es necesario mejorar la capacidad portante de elementos sometidos a solicitaciones de compresión, como columnas y pilas de puentes. El refuerzo externo con polímeros reforzados con fibras (PRF) surgió como una solución que ha dado muy buenos resultados y cuya aplicación se ha incrementado en los últimos años. En este trabajo se evalúa experimentalmente el comportamiento de probetas cilíndricas de hormigón simple y hormigón armado confinadas externamente con PRF y sometidas a carga axial. Se analiza la respuesta tensióndeformación axial y modos de falla, para ambos tipos de especímenes, hormigón simple y armado. En ambos casos el refuerzo externo de PRF incrementa la resistencia y confiere ductilidad a las probetas, confinando al hormigón y conteniéndolo luego de su falla. Se presentan también comparaciones entre valores experimentales de resistencia máxima a compresión y estimaciones realizadas a partir de modelos empíricos de diferentes autores.There are a number of situations where it may become necessary to enhance the load-carrying capacity of elements subjected to compression loads like columns and bridge piles. External reinforcement with fiber reinforced polymers (FRP) appeared with very good results and its use has increased in the last years. The behaviour of simple and reinforced concrete cylinders confined with FRP and subjected to axial load is assessed experimentally in this paper. Axial stress and strain diagram and failure modes for both kind of specimens, simple and reinforced concrete are analyzed. In both cases FRP external reinforcement increases cylinders resistance and induces ductility, confining and containing the concrete after its failure. Comparisons between experimental maximum compression strength values and predictions using empirical models by different authors are also presented.Fil: Kohan, Paul Hernán. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rango, Rita Fernanda. Universidad Nacional de Salta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rougier, Viviana C.. Universidad Tecnologica Nacional. Facultad Regional Concepcion del Uruguay; Argentin

Stage-specific action of matrix metalloproteinases influences progressive hereditary kidney disease.

BackgroundGlomerular basement membrane (GBM), a key component of the blood-filtration apparatus in the in the kidney, is formed through assembly of type IV collagen with laminins, nidogen, and sulfated proteoglycans. Mutations or deletions involving alpha3(IV), alpha4(IV), or alpha5(IV) chains of type IV collagen in the GBM have been identified as the cause for Alport syndrome in humans, a progressive hereditary kidney disease associated with deafness. The pathological mechanisms by which such mutations lead to eventual kidney failure are not completely understood.Methods and findingsWe showed that increased susceptibility of defective human Alport GBM to proteolytic degradation is mediated by three different matrix metalloproteinases (MMPs)--MMP-2, MMP-3, and MMP-9--which influence the progression of renal dysfunction in alpha3(IV)-/- mice, a model for human Alport syndrome. Genetic ablation of either MMP-2 or MMP-9, or both MMP-2 and MMP-9, led to compensatory up-regulation of other MMPs in the kidney glomerulus. Pharmacological ablation of enzymatic activity associated with multiple GBM-degrading MMPs, before the onset of proteinuria or GBM structural defects in the alpha3(IV)-/- mice, led to significant attenuation in disease progression associated with delayed proteinuria and marked extension in survival. In contrast, inhibition of MMPs after induction of proteinuria led to acceleration of disease associated with extensive interstitial fibrosis and early death of alpha3(IV)-/- mice.ConclusionsThese results suggest that preserving GBM/extracellular matrix integrity before the onset of proteinuria leads to significant disease protection, but if this window of opportunity is lost, MMP-inhibition at the later stages of Alport disease leads to accelerated glomerular and interstitial fibrosis. Our findings identify a crucial dual role for MMPs in the progression of Alport disease in alpha3(IV)-/- mice, with an early pathogenic function and a later protective action. Hence, we propose possible use of MMP-inhibitors as disease-preventive drugs for patients with Alport syndrome with identified genetic defects, before the onset of proteinuria

Precalibrating an intermediate complexity climate model

Credible climate predictions require a rational quantification of uncertainty, but full Bayesian calibration requires detailed estimates of prior probability distributions and covariances, which are difficult to obtain in practice. We describe a simplified procedure, termed precalibration, which provides an approximate quantification of uncertainty in climate prediction, and requires only that uncontroversially implausible values of certain inputs and outputs are identified. The method is applied to intermediate-complexity model simulations of the Atlantic meridional overturning circulation (AMOC) and confirms the existence of a cliff-edge catastrophe in freshwaterforcing input space. When uncertainty in 14 further parameters is taken into account, an implausible, AMOC-off, region remains as a robust feature of the model dynamics, but its location is found to depend strongly on values of the other parameters

Bioorthogonal site-selective conjugation of fluorescent dyes to antibodies: method and potential applications

Antibodies are immensely useful tools for biochemical research and have found application in numerous protein detection and purification methods. Moreover, monoclonal antibodies are increasingly utilised as therapeutics or, conjugated to active pharmaceutical ingredients, in targeted chemotherapy. Several reagents and protocols are reported to synthesise fluorescent antibodies for protein target detection and immunofluorescence applications. However, most of these protocols lead to non-selective conjugation, over-labelling or in the worst case antigen binding site modification. Here, we have used the antibody disulphide cleavage and re-bridging strategy to introduce bright fluorescent dyes without loss of the antibody function. The resulting fluorescent IgG1 type antibodies were shown to be effective imaging tools in western blot and direct immunofluorescence experiments