1,999 research outputs found
Методика отловов почвенными ловушками жужелиц сообщества занки
В 2013 г. были изучены сообщества жужелиц в смешанном дубовом лесу в Центрально-Задунайском крае. Нами было расставлено 10 почвенных ловушек, наполненных 10%-ной уксусной кислотой. Ловушки проверялись раз в месяц, всего 8 раз с апреля по ноябрь. В результате было собрано 4357 экземпляров 20 видов жужелиц. Мы проанализировали распределение видов по месяцам и частоту встречаемости видов. Самым распространенным видом оказался Carabus convexus convexu
Stochastic self-assembly of incommensurate clusters
We examine the classic problem of homogeneous nucleation and growth by
deriving and analyzing a fully discrete stochastic master equation. Upon
comparison with results obtained from the corresponding mean-field
Becker-D\"{o}ring equations we find striking differences between the two
corresponding equilibrium mean cluster concentrations. These discrepancies
depend primarily on the divisibility of the total available mass by the maximum
allowed cluster size, and the remainder. When such mass incommensurability
arises, a single remainder particle can "emulsify" or "disperse" the system by
significantly broadening the mean cluster size distribution. This finite-sized
broadening effect is periodic in the total mass of the system and can arise
even when the system size is asymptotically large, provided the ratio of the
total mass to the maximum cluster size is finite. For such finite ratios we
show that homogeneous nucleation in the limit of large, closed systems is not
accurately described by classical mean-field mass-action approaches.Comment: 5 pages, 4 figures, 1 tabl
Phytophilous macrofauna assessments in an important aquatic bird area: the Kis-Balaton protection system
Seventeen macrophyte species were sampled in the area of the Kis-Balaton Protection System
in order to explore the composition and the quantitative characteristics of the macrofauna that
colonize them. Neither the mean densities, nor taxa richness or diversities have shown significant
differences. In all the samples of invertebrate macrofauna Chironomidae and Oligochaeta
were found to be dominant. Accordingly the proportion of higher taxa, composite feeders and
detritus feeders dominated in most of the samples. Ordination method was used to compare
qualitatively the macrofauna composition and only the submerged Ceratophyllum demersum
L. seemed to have a different taxon constitution, while the other macrophytes were more or
less similar in this context
HIV-fertőzött személyek neurokognitív eltérései - hazai prevalenciavizsgálat előzetes eredményei
BACKGROUND AND PURPOSE: The outcome of HIV infection has dramatically improved due to the widespread use of combined antiretroviral therapy (cART). Opportunistic infections faded and internal and hemato-oncological diseases along with neurological conditions came to the forth. Present study is to evaluate neurocognitive performance of the Hungarian HIV infected individuals, at first in this setting Patients and methods - We performed this cross-sectional pilot study within the frames of a national, single-center; prospective study on group of HIV infected patients, analyzing medical data and neurocognitive performance. Based on international recommendations visual memory, visuomotor coordination, non-verbal learning ability, executive functions and reaction time were tested by six domains of a computerized neuropsychological test battery (Vienna Test System). RESULTS: Data of 59 enrolled HIV individuals were analysed; nine of whom were women (15%), median age 42.6 (IQR: 32.4-48.1) years. In 32.2% (n=19) of patients neurocognitive impairment was detected. Duration of infection and cART treatment time tended to be longer in impaired group (not significant). Lower CD4 cell count at the time of examination (p=0.047), psychiatric diseases other than depression (p=0.005) were found significantly associated with impairment; tertiary education qualification were more common (p=0.033) among non-affected patients. By correlation analysis age, infected time and duration of cART were significantly associated with motor deficit. CONCLUSION: HAND was detected in almost one third part of examined patients, which largely corresponds that in developed countries were observed. Duration of infection and of cART therapy associated motor deficit was found to be the most common impairment. This finding might be interpreted by direct effect of HIV, neurotoxicity of antiretro virals and also by accelerated ageing of this population
Bohmian Mechanics and Quantum Information
Many recent results suggest that quantum theory is about information, and
that quantum theory is best understood as arising from principles concerning
information and information processing. At the same time, by far the simplest
version of quantum mechanics, Bohmian mechanics, is concerned, not with
information but with the behavior of an objective microscopic reality given by
particles and their positions. What I would like to do here is to examine
whether, and to what extent, the importance of information, observation, and
the like in quantum theory can be understood from a Bohmian perspective. I
would like to explore the hypothesis that the idea that information plays a
special role in physics naturally emerges in a Bohmian universe.Comment: 25 pages, 2 figure
Distribution of dwell times of a ribosome: effects of infidelity, kinetic proofreading and ribosome crowding
Ribosome is a molecular machine that polymerizes a protein where the sequence
of the amino acid residues, the monomers of the protein, is dictated by the
sequence of codons (triplets of nucleotides) on a messenger RNA (mRNA) that
serves as the template. The ribosome is a molecular motor that utilizes the
template mRNA strand also as the track. Thus, in each step the ribosome moves
forward by one codon and, simultaneously, elongates the protein by one amino
acid. We present a theoretical model that captures most of the main steps in
the mechano-chemical cycle of a ribosome. The stochastic movement of the
ribosome consists of an alternating sequence of pause and translocation; the
sum of the durations of a pause and the following translocation is the time of
dwell of the ribosome at the corresponding codon. We derive the analytical
expression for the distribution of the dwell times of a ribosome in our model.
Whereever experimental data are available, our theoretical predictions are
consistent with those results. We suggest appropriate experiments to test the
new predictions of our model, particularly, the effects of the quality control
mechanism of the ribosome and that of their crowding on the mRNA track.Comment: This is an author-created, un-copyedited version of an article
accepted for publication in Physical Biology. IOP Publishing Ltd is not
responsible for any errors or omissions in this version of the manuscript or
any version derived from it. The definitive publisher authenticated version
is available online at DOI:10.1088/1478-3975/8/2/02600
Power spectra of TASEPs with a localized slow site
The totally asymmetric simple exclusion process (TASEP) with a localized
defect is revisited in this article with attention paid to the power spectra of
the particle occupancy N(t). Intrigued by the oscillatory behaviors in the
power spectra of an ordinary TASEP in high/low density phase(HD/LD) observed by
Adams et al. (2007 Phys. Rev. Lett. 99 020601), we introduce a single slow site
with hopping rate q<1 to the system. As the power spectrum contains
time-correlation information of the particle occupancy of the system, we are
particularly interested in how the defect affects fluctuation in particle
number of the left and right subsystems as well as that of the entire system.
Exploiting Monte Carlo simulations, we observe the disappearance of
oscillations when the defect is located at the center of the system. When the
defect is off center, oscillations are restored. To explore the origin of such
phenomenon, we use a linearized Langevin equation to calculate the power
spectrum for the sublattices and the whole lattice. We provide insights into
the interactions between the sublattices coupled through the defect site for
both simulation and analytical results.Comment: 16 pages, 6 figures; v2: Minor revision
Common NOD2/CARD15 variants are not associated with susceptibility or the clinicopathologic characteristics of sporadic colorectal cancer in Hungarian patients
BACKGROUND: Epidemiological observations suggest that cancer arises from chronically inflamed tissues. Inflammatory bowel disease (IBD) is a typical example as patients with longstanding IBD are at an increased risk for developing colorectal cancer (CRC) and mutations of the NOD2/CARD15 gene increase the risk for Crohn's disease (CD). Recently, NOD2/CARD15 has been associated with a risk for CRC in some studies, which stemmed from ethnically diverse populations. Our aim was to identify common NOD2/CARD15 mutations in Hungarian patients with sporadic CRC. METHODS: A total of 194 sporadic CRC patients (m/f: 108/86, age at diagnosis of CRC: 63.2 ± 9.1 years old) and 200 healthy subjects were included. DNA was screened for SNP8, SNP12 and SNP13 NOD2/CARD15 mutations by denaturing-HPLC and confirmed by direct sequencing. RESULTS: NOD2/CARD15 mutations were found in 28 patients (14.4%) and in 23 controls (11.5%, p = NS). Allele frequencies for SNP8/R702W (1.8% vs. 1.5%) SNP12/G908R (1.8% vs. 1.8%) and SNP13/3020insC (3.6% vs. 2.5%) were also not statistically different between patients and controls. The clinicopathologic characteristics of CRC patients with or without NOD2/CARD15 mutations were not significantly different. CONCLUSION: Our results suggest that common NOD2/CARD15 mutations alone do not contribute to CRC risk in the Hungarian population
Competition for finite resources
The resources in a cell are finite, which implies that the various components
of the cell must compete for resources. One such resource is the ribosomes used
during translation to create proteins. Motivated by this example, we explore
this competition by connecting two totally asymmetric simple exclusion
processes (TASEPs) to a finite pool of particles. Expanding on our previous
work, we focus on the effects on the density and current of having different
entry and exit rates.Comment: 15 pages, 9 figures, v2: minor revisions, v3: additional reference &
minor correction
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