Pressure of thermal excitations in superfluid helium

We find the pressure, due to the thermal excitations of superfluid helium, at the interface with a solid. The separate contributions of phonons, $R^-$ rotons and $R^+$ rotons are derived. The pressure due to $R^-$ rotons is shown to be negative and partially compensates the positive contribution of $R^+$ rotons, so the total roton pressure is positive but several times less than the separate $R^-$ and $R^+$ roton contributions. The pressure of the quasiparticle gas is shown to account for the fountain effect in $HeI I$. An experiment is proposed to observe the negative pressure due to $R^-$ rotons.Comment: 14 pages, 4 figure

Features of the Composition of the Colon Microbiota in Children of the First Year of Life with Functional Gastrointestinal Disorders

Background. The development of functional gastrointestinal disorders (FGID) in children, especially in the first year of life, is a key factor in the formation of an altered colon microbiota and its formation in older age. The article presents both clinical-detailed anamnesis, symptoms of FGID, and bacteriological characteristics – qualitative and quantitative composition of the colon microbiota in children of the first year of life.Aim: to determine the features of the colon microbiota in children of the first year of life with FGID.Materials and methods. The objects of the study were children of the first year of life (n = 28) with a diagnosis of FGID established by a gastroenterologist. The material was divided into two comparison groups, depending on the age of the subjects: the first group included stool sample cultures of children aged from birth to 6 months (n = 17), the second – from 6 to 12 months (n = 11). The bacteriological study of the quantitative and qualitative composition of the contents of the colon was performed using standard methods.Results. According to the anamnesis, colic and flatulence were the key symptoms of FGID (p < 0.05). The results show that the formation of FGID in children from birth to 6 months and from 6 to 12 months may be associated with altered colon microbiota. There was a decrease in the quantitative indicators of the indigenous microbiota: bifidobacteria, E. coli with normal sensitivity and Enterococcus spp., and an increase in the degree of contamination of Klebsiella spp., S. aureus, Clostridium spp.Conclusion. It is shown that the determining factor in reducing the risk of developing FGID in children of the first year of life is a high concentration and diversity of indigenous microbiota

Regularities of disorders in large intestine microbiocenosis under the influence of Klebsiella oxytoca in children 6-12 months old with functional gastrointestinal disorders

Background. Functional disorders of the gastrointestinal tract represent one of the most urgent problems among children in the first year of life. Aim: to determine the peculiarities of microbiocenosis of large intestine in children with varying degrees of dysbiotic conditions of the gastrointestinal tract. Materials and methods. Material for the study included 354 coprological samples isolated from children with functional disorders of the gastrointestinal tract. Depending on the degree of dysbiotic disorders of the colon, the children were divided into comparison groups: group 1 - children with grade 1 dysbiosis (n = 15), group 2 - 45 children with grade 2 dysbiosis, group 3 consisted of 149 children with grade 3, and group 4 consisted of 145 children with grade 3 of dysbiotic disturbances and K. оxytoca vegetation. Identification was performed by standard methods. Results. All four groups were characterized with changes in the qualitative composition of the indigenous biota with predominance of E. coli with atypical properties (haemolytic (up to 26,7 %) and labourmigration activity (to 33,3 %)). Groups with grade 3 dysbiosis were characterized by the presence of aggressive symbiotes in diagnostically significant concentration of S. aureus, Clostridium spp., Candida spp., Enterobacter spp., Proteusspp., P. aeruginosa. Conclusion. The emergence of Klebsiella oxytoca in the colon of children is an evidence of the violation of compensatory-adaptive reactions of the organism, which in turn is characterized by a decrease and a change in the qualitative composition of the indigenous biota by connecting the more aggressive representatives of the bacterial agents

Evolution of a pulse of noninteracting quasiparticles with dispersion and initial angular width

The evolution of a pulse of noninteracting quasiparticles, caused by their different velocities and angular distribution of momenta, is studied theoretically. Equations are found that describe the shape of the pulse surface at any time. The time of the beginning, end and duration of the density of the quasiparticle energy flux is determined at a general spatial point. The quasiparticle energy density is considered at all times and positions, and it is shown that the region of high energy density, in the middle of the pulse, is equal to the initial energy density under certain conditions. These theoretical results are discussed in relation to experimental data on the evolution of a pulse of noninteracting phonons in superfluid helium

Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

Investigations of Structural-Functional Aspects of Epizootic Process in Natural Plague Foci in Siberia

Comprehensively studied have been structural elements of ecosystems of Siberian natural plague foci, as well as levels of integration among epizootic process components, and ways of their functional interaction. Application of the complex approach to the surveillance over structural-functional elements of the parasitic system along with investigations of epizootic process dynamics has provided for identification of peculiarities as regards epizootics development, transformation and evolution of population and carrier/vector coenosis structure in time and space. Revealed is the genetic diversity of plague microbe circulating within the bounds of separate foci and zones of focality. Determined is a long-lasting anti-epidemic effect (more than 20 years) of the field desinsection in the Saglinsk meso-focus of the Tuva natural plague focus

Functional annotation of the transcriptome of Sorghum bicolor in response to osmotic stress and abscisic acid

<p>Abstract</p> <p>Background</p> <p>Higher plants exhibit remarkable phenotypic plasticity allowing them to adapt to an extensive range of environmental conditions. Sorghum is a cereal crop that exhibits exceptional tolerance to adverse conditions, in particular, water-limiting environments. This study utilized next generation sequencing (NGS) technology to examine the transcriptome of sorghum plants challenged with osmotic stress and exogenous abscisic acid (ABA) in order to elucidate genes and gene networks that contribute to sorghum's tolerance to water-limiting environments with a long-term aim of developing strategies to improve plant productivity under drought.</p> <p>Results</p> <p>RNA-Seq results revealed transcriptional activity of 28,335 unique genes from sorghum root and shoot tissues subjected to polyethylene glycol (PEG)-induced osmotic stress or exogenous ABA. Differential gene expression analyses in response to osmotic stress and ABA revealed a strong interplay among various metabolic pathways including abscisic acid and 13-lipoxygenase, salicylic acid, jasmonic acid, and plant defense pathways. Transcription factor analysis indicated that groups of genes may be co-regulated by similar regulatory sequences to which the expressed transcription factors bind. We successfully exploited the data presented here in conjunction with published transcriptome analyses for rice, maize, and Arabidopsis to discover more than 50 differentially expressed, drought-responsive gene orthologs for which no function had been previously ascribed.</p> <p>Conclusions</p> <p>The present study provides an initial assemblage of sorghum genes and gene networks regulated by osmotic stress and hormonal treatment. We are providing an RNA-Seq data set and an initial collection of transcription factors, which offer a preliminary look into the cascade of global gene expression patterns that arise in a drought tolerant crop subjected to abiotic stress. These resources will allow scientists to query gene expression and functional annotation in response to drought.</p