On Multistage Learning a Hidden Hypergraph

Learning a hidden hypergraph is a natural generalization of the classical group testing problem that consists in detecting unknown hypergraph $H_{un}=H(V,E)$ by carrying out edge-detecting tests. In the given paper we focus our attention only on a specific family $F(t,s,\ell)$ of localized hypergraphs for which the total number of vertices $|V| = t$, the number of edges $|E|\le s$, $s\ll t$, and the cardinality of any edge $|e|\le\ell$, $\ell\ll t$. Our goal is to identify all edges of $H_{un}\in F(t,s,\ell)$ by using the minimal number of tests. We develop an adaptive algorithm that matches the information theory bound, i.e., the total number of tests of the algorithm in the worst case is at most $s\ell\log_2 t(1+o(1))$. We also discuss a probabilistic generalization of the problem.Comment: 5 pages, IEEE conferenc

Endothelial function status in hypogonadal men

Background: Type 2 diabetes mellitus (T2DM) and hypogonadism are mutually aggravating diseases associated with the development and progression of cardiovascular pathology. The status of endothelial function in men with T2DM and hypogonadism hasn’t been studied.Aims: To assess the effect of hypogonadism on endothelial function in men with T2DM.Materials and methods: Patients underwent clinical studies, assessment of carbohydrate and lipid metabolism, the content of sex hormones (total testosterone (T), sex hormones binding globulin, free T, luteinizing hormone) and markers of endothelial function (nitric oxide (NO), endothelial nitric oxide synthase type 3 (eNOS3), endothelin, adhesion molecules ICAM-1, VCAM-1, p- and e-selectins, cadherin), ultrasound examinations of endothelium-dependent vasodilation (EDVD) of the brachial artery (BA) and carotid arteries with an assessment of the thickness of intima-media complex (TIM) were performed.Results: The study included 276 men with T2DM (age 54.0[49;60] years), who were divided into 2 groups: 1–124 patients with hypogonadism; 2–152 eugonadal patients. Reduction of the endothelial vasomotor function was detected in 32.4% of patients in the 2st group and in 55.3% of the 1nd group (χ2=6.1; p=0.01), which was associated with a decrease in EDVD by 29.8 % (p<0.001) and an increase in the time of development of maximal BA vasodilation by 30 seconds in patients with hypogonadism (p<0.001). The TIM of the carotid arteries was 10% more in group 1 compared with group 2 (p=0.03). The ­level of NO in the 1st group was reduced by 1.6 times (p=0.001), eNOS3–by 1.5 times (p=0.038) compared with the 2nd group. The concentrations of adhesion molecules were higher in group 1 compared to group 2: VCAM-1 by 32.5% (p<0.001), ICAM-1 by 43.5% (p<0.001), p-selectin–by 19.3% (p=0.004), cadherin–6 times (p<0.001).Conclusion: Hypogonadism in men with T2DM is associated with the development of endothelial dysfunction, which manifests in a weakening of the EDVD and a slowdown in its development, as well as disturbances of the secretory activity of endothelium–a decrease in NO synthesis and activation of the adhesion molecules expression, which can be regarded as an universal pathogenetic mechanism of the development of cardiovascular diseases in combination of T deficiency and T2DM

Functional interplay between chromatin remodeling complexes RSC, SWI/SNF and ISWI in regulation of yeast heat shock genes

Chromatin remodeling is an essential part of transcription initiation. We show that at heat shock gene promoters functional interactions between individual ATP-dependent chromatin remodeling complexes play critical role in both nucleosome displacement and Pol II recruitment. Using HSP12, HSP82 and SSA4 gene promoters as reporters, we demonstrated that while inactivation of SNF2, a critical ATPase of the SWI/SNF complex, primarily affects the HSP12 promoter, depletion of STH1- a SNF2 homolog from the RSC complex reduces histone displacement and abolishes the Pol II recruitment at all three promoters. From these results, we conclude that redundancy between SWI/SNF and RSC complexes is only partial and likely is affecting different chromatin remodeling steps. While inactivation of other individual ATP-dependent chromatin remodeling complexes negligibly affects reporter promoters, combinatorial inactivation of SNF2 and ISW1 has a synergistic effect by diminishing histone loss during heat induction and eliminating Pol II recruitment. Importantly, it also eliminates preloading of HSF on HSP82 and SSA4 promoters before heat shock and diminishes HSF binding during heat shock. These observations suggest that prior action of chromatin remodeling complexes is necessary for the activator binding