748 research outputs found
Self-Focused Attention and Post-Event Processing: Relevance to Social Performance Anxiety and Social Interaction Anxiety
This article originally appeared in the Journal of Cognitive Psychotherapy. The version of record is available at Springer via: http://dx.doi.org/10.1891/0889-8391.28.1.72This study examined the roles of self-focused attention and post-event processing in social performance anxiety and social interaction anxiety. College students (N = 101) completed measures of social performance anxiety, social interaction anxiety, self-focused attention, post-event processing, and beliefs related to social anxiety. Interoceptive self-focused attention and post-event processing predicted social performance anxiety after controlling for social interaction anxiety. The associations with social interaction anxiety were not significant after controlling for social performance anxiety. Associations of behavioral self-focused attention with social performance anxiety and social interaction anxiety were not significant after controlling for interoceptive self-focused attention. No evidence of an interaction between self-focused attention and post-event processing in the prediction of social anxiety was found. This study found no evidence that the associations of interoceptive self-focused attention and post-event processing with social performance anxiety were statistically mediated by high standards, conditional beliefs about self, and unconditional beliefs about self. These results and their theoretical implications are discussed
Can latent heat safely warm blood? – in vitro testing of a portable prototype blood warmer
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background
Trauma/retrieval patients are often in shock and hypothermic. Treatment of such patients usually involves restoring their blood volume with transfusion of blood (stored at 2°C – 6°C) and/or crystalloids or colloids (stored at ambient temperature). Rapid infusion of these cold fluids can worsen or even induce hypothermia in these patients. Warming of intravenous fluids at accident sites has traditionally been difficult due to a lack of suitable portable fluid warmers that are not dependent on mains electrical or battery power. If latent heat, the heat released when a liquid solidifies (an inherently temperature limiting process) can warm intravenous fluids, portable devices without a reliance on electrical energy could be used to reduce the incidence of hypothermia in trauma patients.
Methods
Rapid infusion of red cells into patients was timed to sample typical clinical flow rates.
An approved dry heat blood warmer was compared with a prototype blood warmer using a supercooled liquid latent heat storage material, to warm red cells whilst monitoring inlet and outlet temperatures. To determine the effect of warming on red cell integrity compared to the normal storage lesion of blood, extracellular concentrations of potassium, lactate dehydrogenase and haemoglobin were measured in blood which had been warmed after storage at 2°C – 6°C for 1 to 42 days.
Results
A prototype latent heat fluid warmer consistently warmed red cells from approximately 4°C to approximately 35°C at typical clinical flow rates. Warming of stored blood with latent heat did not affect red cell integrity more than the approved dry heat blood warmer.
Conclusion
Using latent heat as an energy source can satisfactorily warm cold blood or other intravenous fluids to near body temperature, without any adverse affects
Rapidity and k_T dependence of HBT correlations in Au+Au collisions at 200 GeV with PHOBOS
Two-particle correlations of identical charged pion pairs from Au+Au
collisions at sqrt(s_NN) = 200 GeV were measured by the PHOBOS experiment at
RHIC. Data for the most central (0--15%) events were analyzed with
Bertsch-Pratt (BP) and Yano-Koonin-Podgoretskii (YKP) parameterizations using
pairs with rapidities of 0.4 < y < 1.3 and transverse momenta 0.1 < k_T < 1.4
GeV/c. The Bertsch-Pratt radii decrease as a function of pair transverse
momentum. The pair rapidity Y_pipi roughly scales with the source rapidity
Y_YKP, indicating strong dynamical correlations.Comment: 5 pages, 2 figures. To appear in the proceedings of Seventeenth
International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions
(Quark Matter 2004), Oakland, California from January 11-17, 2004. Submitted
to Journal of Physics G: Nuclear and Particle Physic
Pseudorapidity and centrality dependence of the collective flow of charged particles in Au+Au collisions at sqrt{s_NN} = 130 GeV
This paper describes the measurement of collective flow for charged particles
in Au+Au collisions at sqrt{s_NN}} = 130 GeV using the PHOBOS detector at the
Relativistic Heavy Ion Collider (RHIC). An azimuthal anisotropy is observed in
the charged particle hit distribution in the PHOBOS multiplicity detector. This
anisotropy is presented over a wide range of pseudorapidity (eta) for the first
time at this energy. The size of the anisotropy (v_{2}) is thought to probe the
degree of equilibration achieved in these collisions. The result here,averaged
over momenta and particle species, is observed to reach 7% for peripheral
collisions at mid-rapidity, falling off with centrality and increasing |eta|.
Data are presented as a function of centrality for |eta|<1.0 and as a function
of eta, averaged over centrality, in the angular region -5.0<eta<5.3. These
results call into question the common assumption of longitudinal boost
invariance over a large region of rapidity in RHIC collisions.Comment: 5 pages, 4 figures, submitted to Physical Review Letter
Centrality dependence of charged hadron transverse momentum spectra in d+Au collisions at sqrt(s_NN) = 200 GeV
We have measured transverse momentum distributions of charged hadrons
produced in d+Au collisions at sqrt(s_NN) = 200 GeV. The spectra were obtained
for transverse momenta 0.25 < p_T < 6.0 GeV/c, in a pseudorapidity range of 0.2
< eta < 1.4 in the deuteron direction. The evolution of the spectra with
collision centrality is presented in comparison to p+pbarcollisions at the same
collision energy. With increasing centrality, the yield at high transverse
momenta increases more rapidly than the overall particle density, leading to a
strong modification of the spectral shape. This change in spectral shape is
qualitatively different from observations in Au+Au collisions at the same
energy. The results provide important information for discriminating between
different models for the suppression of high-p_T hadrons observed in Au+Au
collisions.Comment: 5 pages, 4 figures, submitted to PR
Energy dependence of elliptic flow over a large pseudorapidity range in Au+Au collisions at RHIC
This paper describes the measurement of the energy dependence of elliptic
flow for charged particles in Au+Au collisions using the PHOBOS detector at the
Relativistic Heavy Ion Collider (RHIC). Data taken at collision energies of
19.6, 62.4, 130 and 200 GeV are shown over a wide range in
pseudorapidity. These results, when plotted as a function of
, scale with approximate linearity throughout ,
implying no sharp changes in the dynamics of particle production as a function
of pseudorapidity or increasing beam energy.Comment: 5 pages, 4 figure
Energy dependence of particle multiplicities in central Au+Au collisions
We present the first measurement of the pseudorapidity density of primary
charged particles in Au+Au collisions at sqrt(s_NN) = 200GeV. For the 6% most
central collisions, we obtain dN_ch/deta|_|eta|<1 = 650 +/- 35 (syst). Compared
to collisions at sqrt(s_NN) = 130GeV, the highest energy studied previously, an
increase by a factor of 1.14 +/- 0.05 is found. The energy dependence of the
pseudorapidity density is discussed in comparison with data from proton-induced
collisions and theoretical predictions.Comment: 4 pages, 6 figures, submitted to PR
The Landscape of Particle Production: Results from PHOBOS
Recent results from the PHOBOS experiment at RHIC are presented, both from
Au+Au collisions from the 2001 run and p+p and d+Au collisions from 2003. The
centrality dependence of the total charged particle multiplicity in p+p and
d+Au show features, such as Npart-scaling and limiting fragmentation, similar
to p+A collisions at lower energies. Multiparticle physics in Au+Au is found to
be local in (pseudo)rapidity, both when observed by HBT correlations and by
forward-backward pseudorapidity correlations. The shape of elliptic flow in
Au+Au, measured over the full range of pseudorapidity, appears to have a very
weak centrality dependence. Identified particle ratios in d+Au reactions show
little difference between the shape of proton and anti-proton spectra, while
the absolute yields show an approximate m_T scaling.Comment: 8 Pages, 11 Figures, Plenary talk at Quark Matter 2004, Oakland, CA,
January 11-18, 200
System size and centrality dependence of charged hadron transverse momentum spectra in Au+Au and Cu+Cu collisions at sqrt(s) = 62.4 and 200 GeV
We present transverse momentum distributions of charged hadrons produced in
Cu+Cu collisions at sqrt(s) = 62.4 and 200 GeV. The spectra are measured for
transverse momenta of 0.25 < p_T < 5.0 GeV/c at sqrt(s) = 62.4 GeV and 0.25 <
p_T < 7.0 GeV/c at sqrt(s) = 200 GeV, in a pseudo-rapidity range of 0.2 < eta <
1.4. The nuclear modification factor R_AA is calculated relative to p+p data at
both collision energies as a function of collision centrality. At a given
collision energy and fractional cross-section, R_AA is observed to be
systematically larger in Cu+Cu collisions compared to Au+Au. However, for the
same number of participating nucleons, R_AA is essentially the same in both
systems over the measured range of p_T, in spite of the significantly different
geometries of the Cu+Cu and Au+Au systems.Comment: 4 pages, 5 figures, submitted to Phys. Rev. Let
System Size, Energy and Centrality Dependence of Pseudorapidity Distributions of Charged Particles in Relativistic Heavy Ion Collisions
We present the first measurements of the pseudorapidity distribution of
primary charged particles in Cu+Cu collisions as a function of collision
centrality and energy, \sqrtsnn = 22.4, 62.4 and 200 GeV, over a wide range of
pseudorapidity, using the PHOBOS detector. Making a global comparison of Cu+Cu
and Au+Au results, we find that the total number of produced charged particles
and the rough shape (height and width) of the pseudorapidity distributions are
determined by the number of nucleon participants. More detailed studies reveal
that a more precise matching of the shape of the Cu+Cu and Au+Au pseudorapidity
distributions over the full range of pseudorapidity occurs for the same
Npart/2A value rather than the same Npart value. In other words, it is the
collision geometry rather than just the number of nucleon participants that
drives the detailed shape of the pseudorapidity distribution and its centrality
dependence at RHIC energies.Comment: Submitted to Physical Review Letter
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