165 research outputs found
Učinci probiotika koji sadrže Bacillus subtilis na crijevnu mikrofloru, kakvoću žutanjka i koncentracije lipida u krvi prepelica nesilica pasmine faraon
The current literature is not comprehensive concerning the influence of Bacillus subtilis on lipid metabolism, egg chemical characteristics, and intestinal microbiota of Japanese quail. The aim of this study was to evaluate the effects of a Bacillus subtilis strain on yolk quality, gut bacterial populations, and total cholesterol and triglyceride concentrations in the plasma of organically farmed Pharaon quail layers. Forty-five-day-old female quails were randomly distributed into four groups of 10 birds each: a no-treatment control group and three test groups receiving powder of Bacillus subtilis DSM 32424 at a minimum rate of 1 × 106 colony forming units per gram, dissolved in drinking water at doses of 50, 75 and 100 mg per kg body weight, daily during 30 days. The use of the probiotic at doses of 50 and 100 mg resulted in significantly reduced faecal staphylococci count on day 30 (P<0.05), while no significant changes were detected in lactobacilli or coliform bacteria. This study gives the first evidence of the influence of Bacillus subtilis on acid value and carotenoid levels in egg yolks laid by quails. Carotenoids were significantly elevated in the 75 mg group on day 30 (P<0.05), but significantly decreased in the 50 and 100 mg groups (P<0.05). Acidity, triglyceride and total cholesterol concentrations in quail serum were not affected significantly by the treatment throughout the study, though their values were reduced. The inclusion of Bacillus subtilis DSM 32424 in drinking water for laying Pharaon quails inhibited faecal staphylococci proliferation and enhanced yolk carotenoid content. Therefore, it can be proposed that including this probiotic in laying quail diets may have beneficial outcomes for both layers and the second generation.Ovaj rad nije sveobuhvatan obzirom na utjecaj Bacillus subtilis na metabolizam lipida, kemijska svojstva jaja te crijevne mikroorganizme japanskih prepelica. Istraživanje je obavljeno u svrhu procjene učinaka Bacillus subtilis soja na kakvoću žutanjka, populacije bakterija u crijevima uz ukupne koncentracije kolesterola i triglicerida u krvi organski uzgajanih prepelica nesilica pasmine faraon. Četrdesetpetodnevne ženke prepelice nasumice su podijeljene u četiri skupine od po 10 ptica: kontrolnu skupinu koja nije primala dodatak prehrani i tri pokusne skupine koje su primale prašak Bacillus subtilis DSM 32424 pri najmanjem postotku od 1 × 106 jedinica koje stvaraju koloniju po gramu, otopljen u pitkoj vodi u dozama od 50, 75 i 100 mg po kilogramu tjelesne težine, svakodnevno tijekom 30 dana. Uporaba probiotika u dozama od 50 i 100 mg rezultirala je značajnim smanjenjem količine fekalnih stafilokoka na 30. dan (P<0,05), dok značajnije promjene laktobacila i koliformnih bakterija nisu otkrivene. Ovo je istraživanje prvi put pokazalo utjecaj Bacillus subtilis na vrijednost kiseline i razine karotenoida u žutanjcima koje nesu prepelice. Karotenoidi su se značajno podigli na 30. dan u skupini koja je primala 75 mg (P<0,05), ali su se i značajno smanjili u skupinama koje su primale 50 i 100 mg (P<0,05). Terapija nije statistički značajno djelovala na kiselinu. Pokusni dodatak nije značajno utjecao niti na koncentracije triglicerida i ukupni kolesterol u krvi prepelica tijekom ispitivanja, premda su te koncentracije dosta smanjene. Na temelju dobivenih rezultata, zaključeno je da je dodavanje Bacillus subtilis DSM 32424 u pitku vodu za prepelice nesilice pasmine Faraon gotovo na svim proučavanim razinama inhibiralo proliferaciju fekalnih stafilokoka i povećalo udio karotenoida u žutanjku. Stoga se može reći da uključivanje probiotika u prehranu prepelica nesilica može imati korisni učinak i na nesilice i na drugu generaciju
Spatial and Wavenumber Resolution of Doppler Reflectometry
Doppler reflectometry spatial and wavenumber resolution is analyzed within
the framework of the linear Born approximation in slab plasma model. Explicit
expression for its signal backscattering spectrum is obtained in terms of
wavenumber and frequency spectra of turbulence which is assumed to be radially
statistically inhomogeneous. Scattering efficiency for both back and forward
scattering (in radial direction) is introduced and shown to be inverse
proportional to the square of radial wavenumber of the probing wave at the
fluctuation location thus making the spatial resolution of diagnostics
sensitive to density profile. It is shown that in case of forward scattering
additional localization can be provided by the antenna diagram. It is
demonstrated that in case of backscattering the spatial resolution can be
better if the turbulence spectrum at high radial wavenumbers is suppressed. The
improvement of Doppler reflectometry data localization by probing beam focusing
onto the cut-off is proposed and described. The possibility of Doppler
reflectometry data interpretation based on the obtained expressions is shown.Comment: http://stacks.iop.org/0741-3335/46/114
Hydrodynamic bubble coarsening in off-critical vapour-liquid phase separation
Late-stage coarsening in off-critical vapour-liquid phase separation is
re-examined. In the limit of bubbles of vapour distributed throughout a
continuous liquid phase, it is argued that coarsening proceeds via inertial
hydrodynamic bubble collapse. This replaces the Lifshitz-Slyozov-Wagner
mechanism seen in binary liquid mixtures. The arguments are strongly supported
by simulations in two dimensions using a novel single-component soft sphere
fluid.Comment: 5 pages, 3 figures, revtex3.
Spinodal decomposition of off-critical quenches with a viscous phase using dissipative particle dynamics in two and three spatial dimensions
We investigate the domain growth and phase separation of
hydrodynamically-correct binary immiscible fluids of differing viscosity as a
function of minority phase concentration in both two and three spatial
dimensions using dissipative particle dynamics. We also examine the behavior of
equal-viscosity fluids and compare our results to similar lattice-gas
simulations in two dimensions.Comment: 34 pages (11 figures); accepted for publication in Phys. Rev.
Evaluation of supramolecular complex of fenbendazole effect on embryonic development
The purpose of the research is to study the embryotropic effect of supramolecular complex of fenbendazole (SMСF).Materials and methods. The experiment to assess the embryotropic properties of SMCF was carried out on 40 white female and 20 male rats in accordance with the Guidelines for the experimental (preclinical) study of new pharmacological substances. Pregnant female rats were divided into 3 experimental and one control groups. SMCF was administered intragastrically on the 1–6 days of embryogenesis (group 1); on the 7–14 days (group 2) and on the 15–19 days (group 3) in three times therapeutic dose – 6,0 mg/kg of active substance. The animals of the control group received saline from the first to the 19th days of pregnancy. Rats were euthanized on the 20th day of pregnancy. The uterus with fetuses was removed after laparotomy, the number of corpora lutea, implantation sites, the number of living, dead and resorbed fetuses were recorded, the weight and diameter of the placenta were determined. The embryos were examined, weighed, the craniocaudal sizes were determined, the levels of total embryonic, preimplantation and postimplantation embryo death were calculated. The fetuses were examined for abnormalities of internal organs and changes in the skeletal system according to the methods of J. G. Wilson (1965) and A. B. Dawson (1926), modified in the department of embryology of the IEM of the USSR Academy of Medical Sciences.Results and discussion. As a result, SMCF does not induce toxic effects on the fetus: mortality rates, size and weight of embryos were at the level of the control group in a threefold therapeutic dose 6,0 mg/kg at intragastric administration on the 1–6; 7–14 and 15–19 days of pregnancy. SMCF did not cause external and internal malformations
Spin-Hall effect and spin-Coulomb drag in doped semiconductors
In this review, we describe in detail two important spin-transport phenomena:
the extrinsic spin-Hall effect (coming from spin-orbit interactions between
electrons and impurities) and the spin-Coulomb drag. The interplay of these two
phenomena is analyzed. In particular, we discuss the influence of scattering
between electrons with opposite spins on the spin current and the spin
accumulation produced by the spin-Hall effect. Future challenges and open
questions are briefly discussed.Comment: Topical revie
Quantitative Proteomics of Intracellular Campylobacter jejuni Reveals Metabolic Reprogramming
Campylobacter jejuni is the major cause of bacterial food-borne illness in the USA and Europe. An important virulence attribute of this bacterial pathogen is its ability to enter and survive within host cells. Here we show through a quantitative proteomic analysis that upon entry into host cells, C. jejuni undergoes a significant metabolic downshift. Furthermore, our results indicate that intracellular C. jejuni reprograms its respiration, favoring the respiration of fumarate. These results explain the poor ability of C. jejuni obtained from infected cells to grow under standard laboratory conditions and provide the bases for the development of novel anti microbial strategies that would target relevant metabolic pathways
DNA Methylation Profiling of the Human Major Histocompatibility Complex: A Pilot Study for the Human Epigenome Project
The Human Epigenome Project aims to identify, catalogue, and interpret genome-wide DNA methylation phenomena. Occurring naturally on cytosine bases at cytosine–guanine dinucleotides, DNA methylation is intimately involved in diverse biological processes and the aetiology of many diseases. Differentially methylated cytosines give rise to distinct profiles, thought to be specific for gene activity, tissue type, and disease state. The identification of such methylation variable positions will significantly improve our understanding of genome biology and our ability to diagnose disease. Here, we report the results of the pilot study for the Human Epigenome Project entailing the methylation analysis of the human major histocompatibility complex. This study involved the development of an integrated pipeline for high-throughput methylation analysis using bisulphite DNA sequencing, discovery of methylation variable positions, epigenotyping by matrix-assisted laser desorption/ionisation mass spectrometry, and development of an integrated public database available at http://www.epigenome.org. Our analysis of DNA methylation levels within the major histocompatibility complex, including regulatory exonic and intronic regions associated with 90 genes in multiple tissues and individuals, reveals a bimodal distribution of methylation profiles (i.e., the vast majority of the analysed regions were either hypo- or hypermethylated), tissue specificity, inter-individual variation, and correlation with independent gene expression data
The Quantum Spin Hall Effect: Theory and Experiment
The search for topologically non-trivial states of matter has become an
important goal for condensed matter physics. Recently, a new class of
topological insulators has been proposed. These topological insulators have an
insulating gap in the bulk, but have topologically protected edge states due to
the time reversal symmetry. In two dimensions the helical edge states give rise
to the quantum spin Hall (QSH) effect, in the absence of any external magnetic
field. Here we review a recent theory which predicts that the QSH state can be
realized in HgTe/CdTe semiconductor quantum wells. By varying the thickness of
the quantum well, the band structure changes from a normal to an "inverted"
type at a critical thickness . We present an analytical solution of the
helical edge states and explicitly demonstrate their topological stability. We
also review the recent experimental observation of the QSH state in
HgTe/(Hg,Cd)Te quantum wells. We review both the fabrication of the sample and
the experimental setup. For thin quantum wells with well width
nm, the insulating regime shows the conventional behavior of vanishingly small
conductance at low temperature. However, for thicker quantum wells ( nm), the nominally insulating regime shows a plateau of residual
conductance close to . The residual conductance is independent of the
sample width, indicating that it is caused by edge states. Furthermore, the
residual conductance is destroyed by a small external magnetic field. The
quantum phase transition at the critical thickness, nm, is also
independently determined from the occurrence of a magnetic field induced
insulator to metal transition.Comment: Invited review article for special issue of JPSJ, 32 pages. For
higher resolution figures see official online version when publishe
Three-dimensional lattice-Boltzmann simulations of critical spinodal decomposition in binary immiscible fluids
We use a modified Shan-Chen, noiseless lattice-BGK model for binary
immiscible, incompressible, athermal fluids in three dimensions to simulate the
coarsening of domains following a deep quench below the spinodal point from a
symmetric and homogeneous mixture into a two-phase configuration. We find the
average domain size growing with time as , where increases
in the range , consistent with a crossover between
diffusive and hydrodynamic viscous, , behaviour. We find
good collapse onto a single scaling function, yet the domain growth exponents
differ from others' works' for similar values of the unique characteristic
length and time that can be constructed out of the fluid's parameters. This
rebuts claims of universality for the dynamical scaling hypothesis. At early
times, we also find a crossover from to in the scaled structure
function, which disappears when the dynamical scaling reasonably improves at
later times. This excludes noise as the cause for a behaviour, as
proposed by others. We also observe exponential temporal growth of the
structure function during the initial stages of the dynamics and for
wavenumbers less than a threshold value.Comment: 45 pages, 18 figures. Accepted for publication in Physical Review
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