1,690 research outputs found
In-medium reduction of the \eta' mass in \sqrt{s_NN} = 200 GeV Au+Au collisions
A reduction of the mass of the \eta'(958) meson may indicate the restoration
of the UA(1) symmetry in a hot and dense hadronic matter, corresponding to the
return of the 9th, "prodigal" Goldstone boson. We report on an analysis of a
combined PHENIX and STAR data set on the intercept parameter of the two-pion
Bose-Einstein correlation functions, as measuremed in \sqrt{s_NN} = 200 GeV
Au+Au collisions at RHIC. To describe this combined PHENIX and STAR dataset, an
in-medium \eta' mass reduction of at least 200 MeV is needed, at the 99.9 %
confidence level in a broad model class of resonance multiplicities. Energy,
system size and centrality dependence of the observed effect is also discussed.Comment: Proceedings of an invited talk of Robert Vertesi at the HCBM 2010
workshop, Budapest, Hungary. Proceedings of an invited talk of Tamas Csorgo
at the ISMD 2010 conference, Antwerp, Belgiu
Effects of chain decays, radial flow and restoration on the low-mass dilepton enhancement in GeV Au+Au reactions
In sqrt(sNN) = 200 GeV Au+Au collisions PHENIX reported a significant
enhancement in the low-mass region (0.1 < m_ee < 0.7 GeV) of the dielectron
spectrum, which is still not fully understood. Several theoretical works and an
indirect measurement suggest that, due to the possible restoration of the
U_A(1) part of the chiral symmetry in a hot and dense medium, the mass of the
eta' meson may substantially decrease. This work reports on a statistically
acceptable description of the PHENIX low-mass dilepton enhancement using a
radial flow dominated meson spectra, chain decays of long-lived resonances and
an in-medium eta' mass modification
Air pollution modelling using a graphics processing unit with CUDA
The Graphics Processing Unit (GPU) is a powerful tool for parallel computing.
In the past years the performance and capabilities of GPUs have increased, and
the Compute Unified Device Architecture (CUDA) - a parallel computing
architecture - has been developed by NVIDIA to utilize this performance in
general purpose computations. Here we show for the first time a possible
application of GPU for environmental studies serving as a basement for decision
making strategies. A stochastic Lagrangian particle model has been developed on
CUDA to estimate the transport and the transformation of the radionuclides from
a single point source during an accidental release. Our results show that
parallel implementation achieves typical acceleration values in the order of
80-120 times compared to CPU using a single-threaded implementation on a 2.33
GHz desktop computer. Only very small differences have been found between the
results obtained from GPU and CPU simulations, which are comparable with the
effect of stochastic transport phenomena in atmosphere. The relatively high
speedup with no additional costs to maintain this parallel architecture could
result in a wide usage of GPU for diversified environmental applications in the
near future.Comment: 5 figure
THE HIDDEN INEQUALITY IN SOCIALISM
In the same time period over which the former socialist countries of Eastern Europe and Central Asia became freer, measured inequality of income for those countries increased. Researchers linked the increase to the egalitarian values of socialism and to the process of economic and political liberalization. We question that link, because we question whether socialism was egalitarian. The inequalities in socialism were hidden but, nevertheless, were real.Transition, Inequality, Socialism, Measurement
Evaluation of Desiccated and Deformed Diaspores from Natural Building Materials
With the increasing sophistication of paleoethnobotanical methods, it is now possible to reconstruct new aspects of the day-to-day life of past peoples, and, ultimately, gain information about their cultivated plants, land-use practices, architecture, diet, and trade. Reliable identification of plant remains, however, remains essential to the study of paleoethno-botany, and there is still much to learn about precise identification. This paper describes and evaluates the most frequent types of deformed desiccated diaspores revealed from adobe bricks used in buildings in Southwestern Hungary that were built primarily between 1850 and 1950. A total of 24,634 diaspores were recovered from 333.05 kg adobe samples. These seeds and fruits belong to 303 taxa, and the majority were arable and ruderal weed species. A total of 98.97% of the diaspores were identified to species. In other cases, identification was possible only to genus or family (0.93% and 0.10% of diaspores, respectively). Difficulties in identification were caused mainly by morphological changes in the size, shape, color, and surface features of diaspores. Most diaspores were darker in color and significantly smaller than fresh or recently desiccated seeds and fruits. Surface features were often absent or fragmented. The most problematic seeds to identify were those of Centaurea cyanus, Consolida regalis, Scleranthus annuus and Daucus carota ssp. carota, which are discussed in detail. Our research aids archaeobotanists in the identification of desiccated and deformed diaspores
A practical review on the measurement tools for cellular adhesion force
Cell cell and cell matrix adhesions are fundamental in all multicellular
organisms. They play a key role in cellular growth, differentiation, pattern
formation and migration. Cell-cell adhesion is substantial in the immune
response, pathogen host interactions, and tumor development. The success of
tissue engineering and stem cell implantations strongly depends on the fine
control of live cell adhesion on the surface of natural or biomimetic
scaffolds. Therefore, the quantitative and precise measurement of the adhesion
strength of living cells is critical, not only in basic research but in modern
technologies, too. Several techniques have been developed or are under
development to quantify cell adhesion. All of them have their pros and cons,
which has to be carefully considered before the experiments and interpretation
of the recorded data. Current review provides a guide to choose the appropriate
technique to answer a specific biological question or to complete a biomedical
test by measuring cell adhesion
Universal Arduino-based experimenting system to support teaching of natural sciences
The rapid evolution of intelligent electronic devices makes information
technology, computer science and electronics strongly related to the teaching
of natural sciences. Today almost everybody has a smart phone that can convert
light, temperature, movement, sound to numbers, therefore all these can be
processed, analysed, displayed, stored, shared by software applications. The
fundamental question is how education can follow this knowledge and how can
education take its advantages. Components and methods of modern technology are
available for education also, teachers and students can play with parts and
tools which were previously used only by engineers. A good example is the very
popular Arduino board which is practically an industrial microcontroller whose
pins are wired to easy-to-use connectors on a printed circuit board. In this
paper we show a universal system which we have developed for the Arduino
platform to support experimenting and understanding of the most fundamental
principles of the operation of modern devices. We show our related educational
concept and discuss the most important features of the system. Open source
hardware and software are available and we provide a number of video tutorials
as well
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