60 research outputs found
Evaluation of handwriting peculiarities utilizing laser speckle contrast imaging
Functional handwriting is a process involving various complex interactions between physical, cognitive and sensory systems. Since muscular motion is of a peculiar nature for each person, handwriting properties, such as pencil pressure and speed of writing, can be considered as a unique marker of identity. Moreover, impairments of handwriting in many cases are connected to neurodevelopmental disorders such as attention deficit hyperactivity disorder, developmental coordination disorder, autism spectrum disorders, Parkinson's disease, etc. From this point of view, investigations of handwriting kinematics and pressure can be highly important for both forensic science and medicine. Commonly, the kinematic and pressure features of handwriting are evaluated using a graphics tablet with a stylus or electronic pens. The production of such devices is quite expensive. Therefore, the development of new methods for individual handwriting analysis is an important and current goal. Laser speckle contrast imaging (LSCI) is a powerful method, which is sensitive to both motion and pressure. Since the developed technique requires the use of only a simple laser diode and camera for image acquisition, LSCI is a cost-effective and practical tool for handwriting analysis. In the current letter we present a robust LSCI-based method for handwriting pressure and kinematics evaluation. The introduced approach was validated by an Archimedean spiral writing task
Mean field approximation of two coupled populations of excitable units
The analysis on stability and bifurcations in the macroscopic dynamics
exhibited by the system of two coupled large populations comprised of
stochastic excitable units each is performed by studying an approximate system,
obtained by replacing each population with the corresponding mean-field model.
In the exact system, one has the units within an ensemble communicating via the
time-delayed linear couplings, whereas the inter-ensemble terms involve the
nonlinear time-delayed interaction mediated by the appropriate global
variables. The aim is to demonstrate that the bifurcations affecting the
stability of the stationary state of the original system, governed by a set of
4N stochastic delay-differential equations for the microscopic dynamics, can
accurately be reproduced by a flow containing just four deterministic
delay-differential equations which describe the evolution of the mean-field
based variables. In particular, the considered issues include determining the
parameter domains where the stationary state is stable, the scenarios for the
onset and the time-delay induced suppression of the collective mode, as well as
the parameter domains admitting bistability between the equilibrium and the
oscillatory state. We show how analytically tractable bifurcations occurring in
the approximate model can be used to identify the characteristic mechanisms by
which the stationary state is destabilized under different system
configurations, like those with symmetrical or asymmetrical inter-population
couplings.Comment: 5 figure
Analysis of undiagnosed tuberculosis-related deaths identified at post-mortem among HIV-infected patients in Russia: a descriptive study
<p>Abstract</p> <p>Background</p> <p>Tuberculosis remains a serious public health threat and economic burden in Russia with escalating rates of drug resistance against a background of growing HIV-epidemic. Samara Oblast is one of the regions of the Russian Federation where more than 1% of the population is affected by the HIV-epidemic; almost half of the cases are concentrated in the largely-industrial city of Togliatti with a population of 800 000.</p> <p>Methods</p> <p>We conducted a retrospective analysis of errors leading to death of HIV-positive patients in general health care hospitals in Togliatti, Russia, in 2008. All (n = 29) cases when tuberculosis was established at autopsy as a cause of death were included.</p> <p>Results</p> <p>Median length of hospital stay was 20 days; in 11 cases the death occurred within the first 24 hours of admission. All cases were known to be HIV-positive prior to admission, however HAART was not initiated for any case, and no relevant tests to assess severity of immunosupression were performed despite their availability. No appropriate diagnostic algorithms were applied to confirm tuberculosis. Major gaps were identified in the work of hospital and consulting physicians including insufficient records keeping. In almost all patients earlier regular HIV-relevant tests were not performed due to poor compliance of patients, many of whom abused alcohol and drugs.</p> <p>Conclusions</p> <p>We conclude that introduction of prompt and accurate diagnostics tests, adequate treatment protocols and intensive training of physicians in management of AIDS and TB is vital. This should include reviewing standards of care for HIV-positive individuals with accompanying social problems.</p
Performance studies of the final prototype for the CASTOR forward calorimeter at the CMS experiment
We present performance results of the final prototype for the CASTOR quartz-tungsten sampling calorimeter, to be installed in the very forward region of the CMS experiment at the LHC. The energy linearity and resolution, the uniformity, as well as the spatial resolution of the prototype to electromagnetic and hadronic showers are studied with 10--200 GeV electrons, 20--350 GeV pions, and 50, 150 GeV muons in beam tests carried out at CERN/SPS in 2007
Pion, kaon, proton and anti-proton transverse momentum distributions from p+p and d+Au collisions at GeV
Identified mid-rapidity particle spectra of , , and
from 200 GeV p+p and d+Au collisions are reported. A
time-of-flight detector based on multi-gap resistive plate chamber technology
is used for particle identification. The particle-species dependence of the
Cronin effect is observed to be significantly smaller than that at lower
energies. The ratio of the nuclear modification factor () between
protons and charged hadrons () in the transverse momentum
range GeV/c is measured to be
(stat)(syst) in minimum-bias collisions and shows little
centrality dependence. The yield ratio of in minimum-bias d+Au
collisions is found to be a factor of 2 lower than that in Au+Au collisions,
indicating that the Cronin effect alone is not enough to account for the
relative baryon enhancement observed in heavy ion collisions at RHIC.Comment: 6 pages, 4 figures, 1 table. We extended the pion spectra from
transverse momentum 1.8 GeV/c to 3. GeV/
Demonstration of the temporal matter-wave Talbot effect for trapped matter waves
We demonstrate the temporal Talbot effect for trapped matter waves using
ultracold atoms in an optical lattice. We investigate the phase evolution of an
array of essentially non-interacting matter waves and observe matter-wave
collapse and revival in the form of a Talbot interference pattern. By using
long expansion times, we image momentum space with sub-recoil resolution,
allowing us to observe fractional Talbot fringes up to 10th order.Comment: 17 pages, 7 figure
Azimuthal anisotropy at RHIC: the first and fourth harmonics
We report the first observations of the first harmonic (directed flow, v_1),
and the fourth harmonic (v_4), in the azimuthal distribution of particles with
respect to the reaction plane in Au+Au collisions at the Relativistic Heavy Ion
Collider (RHIC). Both measurements were done taking advantage of the large
elliptic flow (v_2) generated at RHIC. From the correlation of v_2 with v_1 it
is determined that v_2 is positive, or {\it in-plane}. The integrated v_4 is
about a factor of 10 smaller than v_2. For the sixth (v_6) and eighth (v_8)
harmonics upper limits on the magnitudes are reported.Comment: 6 pages with 3 figures, as accepted for Phys. Rev. Letters The data
tables are at
http://www.star.bnl.gov/central/publications/pubDetail.php?id=3
Transverse-momentum correlations on from mean- fluctuations in Au-Au collisions at 200 GeV
We present first measurements of the pseudorapidity and azimuth
bin-size dependence of event-wise mean transverse momentum
fluctuations for Au-Au collisions at GeV. We invert that
dependence to obtain autocorrelations on differences
interpreted to represent velocity/temperature
distributions on (). The general form of the autocorrelations
suggests that the basic correlation mechanism is parton fragmentation. The
autocorrelations vary strongly with collision centrality, which suggests that
fragmentation is strongly modified by a dissipative medium in the more central
Au-Au collisions relative to peripheral or p-p collisions. \\Comment: 7 pages, 3 figure
The origins and spread of domestic horses from the Western Eurasian steppes
This is the final version. Available on open access from Nature Research via the DOI in this recordData availability: All collapsed and paired-end sequence data for samples sequenced in this study are available in compressed fastq format through the European Nucleotide Archive under accession number PRJEB44430, together with rescaled and trimmed bam sequence alignments against both the nuclear and mitochondrial horse reference genomes. Previously published ancient data used in this study are available under accession numbers PRJEB7537, PRJEB10098, PRJEB10854, PRJEB22390 and PRJEB31613, and detailed in Supplementary Table 1. The genomes of ten modern horses, publicly available, were also accessed as indicated in their corresponding original publications57,61,85-87.NOTE: see the published version available via the DOI in this record for the full list of authorsDomestication of horses fundamentally transformed long-range mobility and warfare. However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling at Botai, Central Asia around 3500 BC. Other longstanding candidate regions for horse domestication, such as Iberia and Anatolia, have also recently been challenged. Thus, the genetic, geographic and temporal origins of modern domestic horses have remained unknown. Here we pinpoint the Western Eurasian steppes, especially the lower Volga-Don region, as the homeland of modern domestic horses. Furthermore, we map the population changes accompanying domestication from 273 ancient horse genomes. This reveals that modern domestic horses ultimately replaced almost all other local populations as they expanded rapidly across Eurasia from about 2000 BC, synchronously with equestrian material culture, including Sintashta spoke-wheeled chariots. We find that equestrianism involved strong selection for critical locomotor and behavioural adaptations at the GSDMC and ZFPM1 genes. Our results reject the commonly held association between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe around 3000 BC driving the spread of Indo-European languages. This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium BC Sintashta culture
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