Bar-Ilan University

About: Bar-Ilan University is a education organization based out in Ramat Gan, Israel. It is known for research contribution in the topics: Population & Poison control. The organization has 12835 authors who have published 34964 publications receiving 995648 citations. The organization is also known as: Bar Ilan University & BIU.

Skip-Over: algorithms and complexity for overloaded systems that allow skips

Abstract: In applications ranging from video reception to telecommunications and packet communication to aircraft control, tasks enter periodically and have fixed response time constraints, but missing a deadline is acceptable, provided most deadlines are met. We call such tasks "occasionally skippable". We look at the problem of uniprocessor scheduling of occasionally skippable periodic tasks in an environment having periodic tasks. We show that making optimal use of skips is NP-hard. We then look at two algorithms called Skip-Over Algorithms (one a variant of earliest deadline first and one of rate monotonic scheduling) that exploit skips. We give schedulability bounds for both.

Spontaneous stratification in granular mixtures

Abstract: Granular materials1–5 segregate according to grain size when exposed to periodic perturbations such as vibrations6–12. Moreover, mixtures of grains of different sizes can also spontaneously segregate in the absence of external perturbations: when such a mixture is simply poured onto a pile, the large grains are more likely to be found near the base, while the small grains are more likely to be near the top13–20. Here we report another size-separation effect, which arises when we pour a granular mixture between two vertical plates: the mixture spontaneously stratifies into alternating layers of small and large grains whenever the large grains have larger angle of repose than the small grains. We find only spontaneous segregation, without stratification, when the large grains have smaller angle of repose than the small grains. The stratification is related to the occurrence of avalanches: during each avalanche, the grains separate into a pair of static layers, with the small grains forming a sublayer underneath the layer of large grains.

SIRT6 protects against pathological damage caused by diet‐induced obesity

Abstract: Summary The NAD+-dependent SIRT6 deacetylase is a therapeutic candidate against the emerging metabolic syndrome epidemic. SIRT6, whose deficiency in mice results in premature aging phenotypes and metabolic defects, was implicated in a calorie restriction response that showed an opposite set of phenotypes from the metabolic syndrome. To explore the role of SIRT6 in metabolic stress, wild type and transgenic (TG) mice overexpressing SIRT6 were fed a high fat diet. In comparison to their wild-type littermates, SIRT6 TG mice accumulated significantly less visceral fat, LDL-cholesterol, and triglycerides. TG mice displayed enhanced glucose tolerance along with increased glucose-stimulated insulin secretion. Gene expression analysis of adipose tissue revealed that the positive effect of SIRT6 overexpression is associated with down regulation of a selective set of peroxisome proliferator-activated receptor-responsive genes, and genes associated with lipid storage, such as angiopoietin-like protein 4, adipocyte fatty acid-binding protein, and diacylglycerol acyltransferase 1, which were suggested as potential targets for drugs to control metabolic syndrome. These results demonstrate a protective role for SIRT6 against the metabolic consequences of diet-induced obesity and suggest a potentially beneficial effect of SIRT6 activation on age-related metabolic diseases.

Structural Basis for Oligosaccharide-Mediated Adhesion of Pseudomonas Aeruginosa in the Lungs of Cystic Fibrosis Patients

Abstract: Pseudomonas aeruginosa galactose- and fucose-binding lectins (PA-IL and PA-IIL) contribute to the virulence of this pathogenic bacterium, which is a major cause of morbidity and mortality in cystic fibrosis patients. The crystal structure of PA-IIL in complex with fucose reveals a tetrameric structure. Each monomer displays a nine-stranded, antiparallel b-sandwich arrangement and contains two close calcium cations that mediate the binding of fucose in a recognition mode unique among carbohydrate-protein interactions. Experimental binding studies, together with theoretical docking of fucose-containing oligosaccharides, are consistent with the assumption that antigens of the Lewis a (Le(a)) series may be the preferred ligands of this lectin. Precise knowledge of the lectin-binding site should allow a better design of new antibacterial-adhesion prophylactics.