676 research outputs found
Two-Proton Correlations near Midrapidity in p+Pb and S+Pb Collisions at the CERN SPS
Correlations of two protons emitted near midrapidity in p+Pb collisions at
450 GeV/c and S+Pb collisions at 200A GeV/c are presented, as measured by the
NA44 Experiment. The correlation effect, which arises as a result of final
state interactions and Fermi-Dirac statistics, is related to the space-time
characteristics of proton emission. The measured source sizes are smaller than
the size of the target lead nucleus but larger than the sizes of the
projectiles. A dependence on the collision centrality is observed; the source
size increases with decreasing impact parameter. Proton source sizes near
midrapidity appear to be smaller than those of pions in the same interactions.
Quantitative agreement with the results of RQMD (v1.08) simulations is found
for p+Pb collisions. For S+Pb collisions the measured correlation effect is
somewhat weaker than that predicted by the model simulations, implying either a
larger source size or larger contribution of protons from long-lived particle
decays.Comment: 10 pages (LaTeX) text, 4 (EPS) figures; accepted for publication in
Phys. Lett.
Effects of social-cognitive processing demands and structural importance on narrative recall: Differences between children, adolescents, and adults
This study examined the contributions of developmental changes in social-cognitive ability throughout adolescence to the development of narrative comprehension. We measured the effects of sensitivity to the causal structure of narratives and of sensitivity to differences in social-cognitive processing demands on narrative recall by children (8–10 years old), adolescents (13–15 years old), and adults (19–21 years old). Generalized mixed-effects models for dichotomous variables revealed that social-cognitive processing demands of story elements predicted differences in narrative recall between the age groups, over and above the causal importance of story elements. Children's and adolescents' recall of the narrative differed from that of adults, and these differences were most apparent for social-cognitive aspects of the narrative. These findings suggest that immature social-cognitive abilities limit narrative comprehension in childhood and adolescence and, in doing so, contribute to our understanding of the interaction between reader characteristics and text characteristics in the development of narrative comprehension.Development Psychopathology in context: schoo
Caracterização do nĂvel de oxidação de glutationa durante a dormĂŞncia hibernal em gemas de macieira.
A macieira (Malus x domestica) apresenta a queda de folhas no final do ciclo e o estabelecimento da donnência hibemal (endodonnência). Durante a endodonnência, as plantas necessitam de regularidade e intensidade de baixas temperaturas para que iniciem a brotação e se estabeleça um novo ciclo vegetativo e produtivo. Entretanto, em regiões de clima temperado, como a Região Sul do Brasil, em muitos invemos ocorrem flutuações de temperatura que resultam em quedas de produção.Resumo
Lambda-proton correlations in relativistic heavy ion collisions
The prospect of using lambda-proton correlations to extract source sizes in
relativistic heavy ion collisions is investigated. It is found that the strong
interaction induces a large peak in the correlation function that provides more
sensitive source size measurements than two-proton correlations under some
circumstances. The prospect of using lambda-proton correlations to measure the
time lag between lambda and proton emissions is also studied.Comment: 4 pages, 3 figure, revtex style. Two short paragraphs are added at
referees' recommendations. Phys. Rev. Lett. in pres
Baryon phase-space density in heavy-ion collisions
The baryon phase-space density at mid-rapidity from central heavy-ion
collisions is estimated from proton spectra with interferometry and deuteron
coalescence measurements. It is found that the mid-rapidity phase-space density
of baryons is significantly lower at the SPS than the AGS, while those of total
particles (pion + baryon) are comparable. Thermal and chemical equilibrium
model calculations tend to over-estimate the phase-space densities at both
energies.Comment: 5 pages, 2 tables, no figure. RevTeX style. Accepted for publication
in Phys. Rev. C Rapid Communicatio
Rapid estimation of catalytic efficiency by cumulative atomic multipole moments:application to ketosteroid isomerase mutants
We
propose a simple atomic multipole electrostatic model to rapidly
evaluate the effects of mutation on enzyme activity and test its performance
on wild-type and mutant ketosteroid isomerase. The predictions of
our atomic multipole model are similar to those obtained with symmetry-adapted
perturbation theory at a fraction of the computational cost. We further
show that this approach is relatively insensitive to the precise amino
acid side chain conformation in mutants and may thus be useful in
computational enzyme (re)Âdesign
Characterization of the seismic environment at the Sanford Underground Laboratory, South Dakota
An array of seismometers is being developed at the Sanford Underground
Laboratory, the former Homestake mine, in South Dakota to study the properties
of underground seismic fields and Newtonian noise, and to investigate the
possible advantages of constructing a third-generation gravitational-wave
detector underground. Seismic data were analyzed to characterize seismic noise
and disturbances. External databases were used to identify sources of seismic
waves: ocean-wave data to identify sources of oceanic microseisms, and surface
wind-speed data to investigate correlations with seismic motion as a function
of depth. In addition, sources of events contributing to the spectrum at higher
frequencies are characterized by studying the variation of event rates over the
course of a day. Long-term observations of spectral variations provide further
insight into the nature of seismic sources. Seismic spectra at three different
depths are compared, establishing the 4100-ft level as a world-class low
seismic-noise environment.Comment: 29 pages, 16 figure
Electrocardiogram Monitoring Wearable Devices and Artificial-Intelligence-Enabled Diagnostic Capabilities: A Review
Worldwide, population aging and unhealthy lifestyles have increased the incidence of high-risk health conditions such as cardiovascular diseases, sleep apnea, and other conditions. Recently, to facilitate early identification and diagnosis, efforts have been made in the research and development of new wearable devices to make them smaller, more comfortable, more accurate, and increasingly compatible with artificial intelligence technologies. These efforts can pave the way to the longer and continuous health monitoring of different biosignals, including the real-time detection of diseases, thus providing more timely and accurate predictions of health events that can drastically improve the healthcare management of patients. Most recent reviews focus on a specific category of disease, the use of artificial intelligence in 12-lead electrocardiograms, or on wearable technology. However, we present recent advances in the use of electrocardiogram signals acquired with wearable devices or from publicly available databases and the analysis of such signals with artificial intelligence methods to detect and predict diseases. As expected, most of the available research focuses on heart diseases, sleep apnea, and other emerging areas, such as mental stress. From a methodological point of view, although traditional statistical methods and machine learning are still widely used, we observe an increasing use of more advanced deep learning methods, specifically architectures that can handle the complexity of biosignal data. These deep learning methods typically include convolutional and recurrent neural networks. Moreover, when proposing new artificial intelligence methods, we observe that the prevalent choice is to use publicly available databases rather than collecting new data
Bose-Einstein Correlations for Three-Dimensionally Expanding, Cylindrically Symmetric, Finite Systems
The parameters of the Bose-Einstein correlation function may obey an {\it
-scaling}, as observed in and reactions at CERN SPS.
This -scaling implies that the Bose-Einstein correlation functions view
only a small part of the big and expanding system. The full sizes of the
expanding system at the last interaction are shown to be measurable with the
help the invariant momentum distribution of the emitted particles. A vanishing
duration parameter can also be generated in the considered model-class with a
specific dependence.Comment: 35 pages, ReVTeX, LaTeX, no figures, discussion extende
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