1,094 research outputs found
Nucleon-Gold Collisions at 200 AGeV Using Tagged d+Au Interactions in PHOBOS
Forward calorimetry in the PHOBOS detector has been used to study charged
hadron production in d+Au, p+Au and n+Au collisions at sqrt(s_nn) = 200 GeV.
The forward proton calorimeter detectors are described and a procedure for
determining collision centrality with these detectors is detailed. The
deposition of energy by deuteron spectator nucleons in the forward calorimeters
is used to identify p+Au and n+Au collisions in the data. A weighted
combination of the yield of p+Au and n+Au is constructed to build a reference
for Au+Au collisions that better matches the isospin composition of the gold
nucleus. The p_T and centrality dependence of the yield of this improved
reference system is found to match that of d+Au. The shape of the charged
particle transverse momentum distribution is observed to extrapolate smoothly
from pbar+p to central d+Au as a function of the charged particle
pseudorapidity density. The asymmetry of positively- and negatively-charged
hadron production in p+Au is compared to that of n+Au. No significant asymmetry
is observed at mid-rapidity. These studies augment recent results from
experiments at the LHC and RHIC facilities to give a more complete description
of particle production in p+A and d+A collisions, essential for the
understanding the medium produced in high energy nucleus-nucleus collisions.Comment: 17 pages, 18 figure
The Linearity of the Cosmic Expansion Field from 300 to 30,000 km/s and the Bulk Motion of the Local Supercluster with Respect to the CMB
The meaning of "linear expansion" is explained. Particularly accurate
relative distances are compiled and homogenized a) for 246 SNe Ia and 35
clusters with v<30,000 km/s, and b) for relatively nearby galaxies with 176
TRGB and 30 Cepheid distances. The 487 objects define a tight Hubble diagram
from 300-30,000 km/s implying individual distance errors of <7.5%. Here the
velocities are corrected for Virgocentric steaming (locally 220 km/s) and - if
v_220>3500 km/s - for a 495 km/s motion of the Local Supercluster towards the
warm CMB pole at l=275, b=12; local peculiar motions are averaged out by large
numbers. A test for linear expansion shows that the corrected velocities
increase with distance as predicted by a standard model with q_0=-0.55
[corresponding to (Omega_M, Omega_Lambda)=(0.3,0.7)], but the same holds - due
to the distance limitation of the present sample - for a range of models with
q_0 between ~0.00 and -1.00. For these models H_0 does not vary systematically
by more than +/-2.3% over the entire range. Local, distance-dependent
variations are equally limited to 2.3% on average. In particular the proposed
Hubble Bubble of Zehavi et al. and Jha et al. is rejected at the 4sigma level.
- Velocity residuals in function of the angle from the CMB pole yield a
satisfactory apex velocity of 448+/-73 km/s and a coherence radius of the Local
Supercluster of ~3500 km/s (~56 Mpc), beyond which galaxies are seen on average
at rest in co-moving coordinates with respect to the CMB. Since no obvious
single accelerator of the Local Supercluster exists in the direction of the CMB
dipole its motion must be due to the integral gravitational force of all
surrounding structures. Most of the gravitational dipole comes probably from
within 5000 km/s.Comment: 52 pages, 12 figures, 6 tables; accepted for publication in The
Astrophysical Journal. v2: minor changes in both text and figure
A Case Study of Convectively Sourced Water Vapor Observed in the Overworld Stratosphere over the United States
On 27 August 2013, during the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys field mission, NASA's ER2 research aircraft encountered a region of enhanced water vapor, extending over a depth of approximately 2 km and a minimum areal extent of 20,000 km(exp 2) in the stratosphere (375 K to 415 K potential temperature), south of the Great Lakes (42N, 90W). Water vapor mixing ratios in this plume, measured by the Harvard Water Vapor instrument, constitute the highest values recorded in situ at these potential temperatures and latitudes. An analysis of geostationary satellite imagery in combination with trajectory calculations links this water vapor enhancement to its source, a deep tropopausepenetrating convective storm system that developed over Minnesota 20 h prior to the aircraft plume encounter. High resolution, groundbased radar data reveal that this system was composed of multiple individual storms, each with convective turrets that extended to a maximum of ~4 km above the tropopause level for several hours. In situ water vapor data show that this storm system irreversibly delivered between 6.6 kt and 13.5 kt of water to the stratosphere. This constitutes a 2025% increase in water vapor abundance in a column extending from 115 hP to 70 hPa over the plume area. Both in situ and satellite climatologies show a high frequency of localized water vapor enhancements over the central U.S. in summer, suggesting that deep convection can contribute to the stratospheric water budget over this region and season
Molecular excitation in the Interstellar Medium: recent advances in collisional, radiative and chemical processes
We review the different excitation processes in the interstellar mediumComment: Accepted in Chem. Re
Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF
The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at
the Fermilab Long-Baseline Neutrino Facility (LBNF) is described
The retirement experiences of elite female gymnasts: Self identity and the physical self
This study explored experiences of retirement from elite sport among a sample of retired female gymnasts. Given the young age at which female gymnasts begin and end their sport careers, particular attention was afforded to the role of identity and the physical self in the process of adaptation. Retrospective, semi-structured interviews were conducted and interview transcripts analyzed using interpretative phenomenological analysis. Analysis indicated that retirement from gymnastics engendered adjustment difficulties for six of the seven participants. Identity loss was particularly salient, and for two gymnasts, physical changes associated with retirement were a further source of distress. The challenge of athletic retirement was intensified because the gymnasts had heavily invested in sport during adolescence, a period demarcated for the pursuit of an identity. Furthermore, their retirement coincided with a time when adolescents typically undergo profound changes physiologically. Practical suggestions to facilitate athletes' disengagement from sport are discussed
Genital herpes evaluation by quantitative TaqMan PCR: correlating single detection and quantity of HSV-2 DNA in cervicovaginal lavage fluids with cross-sectional and longitudinal clinical data
Abstract Objective To evaluate the utility of a single quantitative PCR (qPCR) measurement of HSV (HSV-1&2) DNA in cervicovaginal lavage (CVL) specimens collected from women with predominantly chronic HSV-2 infection in assessing genital HSV shedding and the clinical course of genital herpes (GH) within a cohort with semiannual schedule of follow up and collection of specimens. Methods Two previously described methods used for detection of HSV DNA in mucocutaneous swab samples were adapted for quantification of HSV DNA in CVLs. Single CVL specimens from 509 women were tested. Presence and quantity of CVL HSV DNA were explored in relation to observed cross-sectional and longitudinal clinical data. Results The PCR assay was sensitive and reproducible with a limit of quantification of ~50 copies per milliliter of CVL. Overall, 7% of the samples were positive for HSV-2 DNA with median log10 HSV-2 DNA copy number of 3.9 (IQR: 2.6-5.7). No HSV-1 was detected. Presence and quantity of HSV-2 DNA in CVL directly correlated with the clinical signs and symptoms of presence of active symptomatic disease with frequent recurrences. Conclusion Single qPCR measurement of HSV DNA in CVL fluids of women with chronic HSV-2 infection provided useful information for assessing GH in the setting of infrequent sampling of specimens. Observed positive correlation of the presence and quantity of HSV-2 DNA with the presence of active and more severe course of HSV-2 infection may have clinical significance in the evaluation and management of HSV-2 infected patients
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