722 research outputs found
Thermodynamics of tubelike flexible polymers
In this work we present the general phase behavior of short tubelike flexible
polymers. The geometric thickness constraint is implemented through the concept
of the global radius of curvature. We use sophisticated Monte Carlo sampling
methods to simulate small bead-stick polymer models with Lennard-Jones
interaction among non-bonded monomers. We analyze energetic fluctuations and
structural quantities to classify conformational pseudophases. We find that the
tube thickness influences the thermodynamic behavior of simple tubelike
polymers significantly, i.e., for given temperature, the formation of secondary
structures strongly depends on the tube thickness
Properties of the non-Gaussian fixed point in 4D compact U(1) lattice gauge theory
We examine selected properties of the gauge-ball spectrum and fermionic
variables in the vicinity of the recently discussed non-Gaussian fixed point of
4D compact U(1) lattice gauge theory within the quenched approximation.
Approaching the critical point from within the confinement phase, our data
support scaling of gauge-ball states in units of the string tension
square root. The analysis of the chiral condensate within the framework of a
scaling form for the equation of state suggests non mean-field values for the
magnetic exponents and .Comment: 73K postscript fil
Role of vibrational entropy in the stabilization of the high-temperature phases of iron
The phonon dispersions of the bcc and fcc phases of pure iron ({\alpha}-Fe,
{\gamma}-Fe and {\delta}-Fe) at ambient pressure were investigated close to the
respective phase transition temperatures. In the open bcc structure the
transverse phonons along T1 [{\xi}{\xi}0] and T1 [{\xi}{\xi}2{\xi}] are of
particularly low energy. The eigenvectors of these phonons correspond to
displacements needed for the transformation to the fcc {\gamma}-phase.
Especially these phonons, but also all other phonons soften considerably with
increasing temperature. Comparing thermodynamic properties of the fcc and the
two bcc phases it is shown that the high temperature bcc phase is stabilized
predominantly by vibrational entropy, whereas for the stabilization of the fcc
phase electronic entropy provides an equal contribution.Comment: to appear in Physical Review
Universality of the gauge-ball spectrum of the four-dimensional pure U(1) gauge theory
We continue numerical studies of the spectrum of the pure U(1) lattice gauge
theory in the confinement phase, initiated in our previous work. Using the
extended Wilson action we address the question of universality of the phase
transition line in the () plane between the confinement and the
Coulomb phases. Our present results at for the gauge-ball
spectrum are fully consistent with the previous results obtained at . Again, two different correlation length exponents,
and , are obtained in different channels. We also confirm
the stability of the values of these exponents with respect to the variation of
the distance from the critical point at which they are determined. These
results further demonstrate universal critical behaviour of the model at least
up to correlation lengths of 4 lattice spacings when the phase transition is
approached in some interval at .Comment: 16 page
A neural network z-vertex trigger for Belle II
We present the concept of a track trigger for the Belle II experiment, based
on a neural network approach, that is able to reconstruct the z (longitudinal)
position of the event vertex within the latency of the first level trigger. The
trigger will thus be able to suppress a large fraction of the dominating
background from events outside of the interaction region. The trigger uses the
drift time information of the hits from the Central Drift Chamber (CDC) of
Belle II within narrow cones in polar and azimuthal angle as well as in
transverse momentum (sectors), and estimates the z-vertex without explicit
track reconstruction. The preprocessing for the track trigger is based on the
track information provided by the standard CDC trigger. It takes input from the
2D () track finder, adds information from the stereo wires of the
CDC, and finds the appropriate sectors in the CDC for each track in a given
event. Within each sector, the z-vertex of the associated track is estimated by
a specialized neural network, with a continuous output corresponding to the
scaled z-vertex. The input values for the neural network are calculated from
the wire hits of the CDC.Comment: Proceedings of the 16th International workshop on Advanced Computing
and Analysis Techniques in physics research (ACAT), Preprint, reviewed
version (only minor corrections
Vaccine Hesitancy in Central Switzerland: Identifying and Characterizing Undervaccinated Children in a Pediatric Emergency Department
Proactive Aging Mitigation in CGRAs through Utilization-Aware Allocation
Resource balancing has been effectively used to mitigate the long-term aging
effects of Negative Bias Temperature Instability (NBTI) in multi-core and
Graphics Processing Unit (GPU) architectures. In this work, we investigate this
strategy in Coarse-Grained Reconfigurable Arrays (CGRAs) with a novel
application-to-CGRA allocation approach. By introducing important extensions to
the reconfiguration logic and the datapath, we enable the dynamic movement of
configurations throughout the fabric and allow overutilized Functional Units
(FUs) to recover from stress-induced NBTI aging. Implementing the approach in a
resource-constrained state-of-the-art CGRA reveals lifetime
improvement with negligible performance overheads and less than increase
in area.Comment: Please cite this as: M. Brandalero, B. N. Lignati, A. Carlos
Schneider Beck, M. Shafique and M. H\"ubner, "Proactive Aging Mitigation in
CGRAs through Utilization-Aware Allocation," 2020 57th ACM/IEEE Design
Automation Conference (DAC), San Francisco, CA, USA, 2020, pp. 1-6, doi:
10.1109/DAC18072.2020.921858
Interactions of human microglia cells with Japanese encephalitis virus
Japanese encephalitis virus (JEV) is a neurotropic flavivirus causing mortality and morbidity in humans. Severe Japanese encephalitis cases display strong inflammatory responses in the central nervous system and an accumulation of viral particles in specific brain regions. Microglia cells are the unique brain-resident immune cell population with potent migratory functions and have been proposed to act as a viral reservoir for JEV. Animal models suggest that the targeting of microglia by JEV is partially responsible for inflammatory reactions in the brain. Nevertheless, the interactions between human microglia and JEV are poorly documented.Methods: Using human primary microglia and a new model of human blood monocyte-derived microglia, the present study explores the interaction between human microglia and JEV as well as the role of these cells in viral transmission to susceptible cells. To achieve this work, vaccine-containing inactivated JEV and two live JEV strains were applied on human microglia.Results: Live JEV was non-cytopathogenic to human microglia but increased levels of CCL2, CXCL9 and CXCL10 in such cultures. Furthermore, human microglia up-regulated the expression of the fraktalkine receptor CX3CR1 upon exposure to both JEV vaccine and live JEV. Although JEV vaccine enhanced MHC class II on all microglia, live JEV enhanced MHC class II mainly on CX3CR1+ microglia cells. Importantly, human microglia supported JEV replication, but infectivity was only transmitted to neighbouring cells in a contact-dependent manner.Conclusion: Our findings suggest that human microglia may be a source of neuronal infection and sustain JEV brain pathogenesis
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