1,479 research outputs found
A Cluster of Class I/f/II YSOs Discovered Near the Cepheid SU Cas
Preliminary constraints are placed on a cluster of YSOs (J2000 02:54:31.4
+69:20:32.5) discovered in the field of the classical Cepheid SU Cas. WISE 3.4,
4.6, 12, and 22 um images reveal that the cluster deviates from spherical
symmetry and exhibits an apparent diameter of 3x6'. SEDs constructed using
2MASS Ks (2.2 um) and WISE photometry indicate that 19 (36%) class I, 21 (40%)
class f, and 13 (25%) class II objects lie r<3' from the cluster center.
Conversely, 11 (18%) class I, 13 (21%) class f, and 37 (61%) class II objects
were detected for r>3'. Approximately 50% of the class I sources within r<3'
were classified solely using WISE photometry owing to the absence of detections
by 2MASS.Comment: Accepted for Publication (MNRAS
Effectiveness of Gaming in Creating Cultural Awareness
Despite the emphasis on cultural competency education in the United States for the past three decades, inequities and disparities in healthcare continue to persist, particularly among minority populations. With the current growing gap in provider and patient cultural congruence, how effectively we train students to work with diverse populations in healthcare settings warrants attention. This article presents the results of a qualitative study on the effectiveness of experiential learning, in the form of the game BaFa’ BaFa,’ in raising cultural awareness among students of health professions. Using thematic analysis, the authors analyzed written reflections from student participants. The findings support earlier studies, conducted mainly outside of healthcare, on the effectiveness of gaming in nurturing cultural awareness
An explanation of the Newman-Janis Algorithm
After the original discovery of the Kerr metric, Newman and Janis showed that
this solution could be ``derived'' by making an elementary complex
transformation to the Schwarzschild solution. The same method was then used to
obtain a new stationary axisymmetric solution to Einstein's field equations now
known as the Kerr-newman metric, representing a rotating massive charged black
hole. However no clear reason has ever been given as to why the Newman-Janis
algorithm works, many physicist considering it to be an ad hoc procedure or
``fluke'' and not worthy of further investigation. Contrary to this belief this
paper shows why the Newman-Janis algorithm is successful in obtaining the
Kerr-Newman metric by removing some of the ambiguities present in the original
derivation. Finally we show that the only perfect fluid generated by the
Newman-Janis algorithm is the (vacuum) Kerr metric and that the only Petrov
typed D solution to the Einstein-Maxwell equations is the Kerr-Newman metric.Comment: 14 pages, no figures, submitted to Class. Quantum Gra
From a certain point of view: sensory phenomenological envisionings of running space and place
The precise ways in which we go about the mundane, repetitive, social actions of everyday life are central concerns of ethnographers and theorists working within the traditions of the sociology of the mundane and sociological phenomenology. In this article, we utilize insights derived from sociological phenomenology and the newly developing field of sensory sociology to investigate a particular, mundane, and embodied social practice, that of training for distance running in specific places: our favored running routes. For, despite a growing body of ethnographic studies of particular sports, little analytic attention has been devoted to the actual, concrete practices of “doing” or “producing” sporting activity, particularly from a sensory ethnographic perspective. Drawing upon data from a 2-year joint autoethnographic research project, here we explore the visual dimension, focusing upon three key themes in relation to our runners’ visualization of, respectively, (1) hazardous places, (2) performance places, (3) the time–space–place nexus
Electron impact dissociation cross sections for C2F6
Absolute total dissociation cross sections for electron impact, σt,diss, from 8 to 700 eV are reported for C2F6. A dense set of data was obtained in the technologically important 8–30 eV energy range relevant to modelling the type of plasmas used in both fundamental and applied scientific investigations. The threshold for dissociation was found to be 12.0 ± 0.2 eV and appears to be associated with a Rydberg state. Estimated values for the total neutral dissociation cross section, σneut,diss, were obtained by subtracting the ionization cross sections (all ionizing events cause dissociation) from the total dissociation cross section. It is shown that a calibration error in a paper by one of us (HFW) caused a distortion of several previous investigations. When the data from the present work are used to recalibrate data from swarm experiments, agreement becomes quite reasonable. There is now a consistent set of data obtained from several investigators which describe the dissociation of C2F6. Neutral dissociation cross sections are obtained from electron-impact excitation calculations and found to be in reasonable agreement with measurements over most of the energy range
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The effect of lifestyle and risk factor modification on occlusive peripheral arterial disease outcomes: standard healthcare vs structured programme—for a randomised controlled trial protocol
© The Author(s) 2021. Background: Peripheral arterial disease (PAD) affects more than 200 million of the global population. PAD represents a marker for premature cardiovascular events. Patients with PAD, even in the absence of a history of myocardial infarction or ischemic stroke, have approximately the same relative risk of death from cardiovascular causes as patients with a history of coronary or cerebrovascular disease. Despite the high prevalence of PAD and the strong association with cardiovascular morbidity and mortality, patients with PAD are less likely to receive appropriate treatment for their atherosclerotic risk factors than those who are being treated for coronary artery disease. Atherosclerotic risk factor identification and modification play an important role in reducing the number of adverse outcomes among patients with atherosclerosis. Risk reduction therapy decreases the risk of cardiovascular mortality and morbidity in patients with PAD. In this study, we aim to evaluate the effectiveness of a lifestyle and risk factor modification intervention programme in achieving treatment goals for PAD risk factors. Methods: This is a randomised, parallel group, active-control trial to compare the effectiveness of the risk factor modification intervention programme to standard healthcare in a tertiary vascular care centre, in the reduction of modified risk factors in PAD patients. The primary outcome of this study is to evaluate the effectiveness of a lifestyle and risk factor modification intervention programme in achieving treatment goals for PAD risk factors at 3 and 12 months. The secondary outcomes are to compare the impact of the programme on clinical outcomes in PAD patients at 12 months. Secondary outcomes include amputation-free survival, clinical improvement, haemodynamic improvement, need for revascularisation procedures, outcomes of revascularisation procedures, changes in quality of life and the incidence of adverse events. Discussion: This study will provide clear evidence on the effectiveness of a lifestyle and risk factor modification intervention programme in achieving treatment goals for PAD risk factors, through a high-quality, well-powered clinical trial. Trial registration: This trial was registered (11/07/2017) on the European Clinical Trials Database (EudraCT number 2017-002964-41) and ClinicalTrials.gov (NCT03935776) which was registered on 02 May 2019.Ministry of Higher Education and Scientific Research, Libyan Embassy medical doctorate scholarshi
Pre-Main Sequence stars in the star forming complex Sh 2-284
Located at the galactic anticenter, Sh 2-284 is a HII region which harbors
several young open clusters; Dolidze 25, a rare metal poor (Z~0.004) young
cluster, is one of these. Given its association with Sh 2-284, it is reasonable
to assume the low metallicity for the whole HII region. Sh~2-284 is expected to
host a significant population of Pre-Main Sequence (PMS) stars of both low and
intermediate mass stars (Herbig Ae stars). We aim at characterizing these stars
by means of a spectroscopic and photometric survey conducted with VIMOS@VLT and
complemented with additional optical and infrared observations. In this survey
we selected and characterized 23 PMS objects. We derived the effective
temperature, the spectral energy distribution and luminosity of these objects;
using theoretical PMS evolutionary tracks, with the appropriate metallicity, we
estimated the mass and the age of the studied objects. We also estimated a
distance of 4 Kpc for Sh 2-284 by using spectroscopic parallax of 3 OB stars.
From the age determination we concluded that triggered star formation is in act
in this region. Our results show that a significant fraction of the young
stellar objects (YSOs) may have preserved their disk/envelopes, in contrast
with what is found in other recent studies of low-metallicity star forming
regions in the Galaxy. Finally, among the 23 bona fide PMS stars, we identified
8 stars which are good candidates to pulsators of the delta Scuti type.Comment: accepted for publication in MNRA
Results of examination of the returned Surveyor 3 samples for particulate impacts.
The Meteoroid Sciences Branch at the Manned Spacecraft Center (MSC) examined the Surveyor 3 television camera housing and the length of polished aluminum tube retrieved by the Apollo 12 crew.B. G. Cour-Palais, R. E. Flaherty, R. W. High, D. J. Kessler, D.S. McKay, and H. A. Zoo
MBM 12: young protoplanetary discs at high galactic latitude
(abridged) We present Spitzer infrared observations to constrain disc and
dust evolution in young T Tauri stars in MBM 12, a star-forming cloud at high
latitude with an age of 2 Myr and a distance of 275 pc. The region contains 12
T Tauri systems, with primary spectral types between K3 and M6; 5 are weak-line
and the rest classical T Tauri stars. We first use MIPS and literature
photometry to compile spectral energy distributions for each of the 12 members
in MBM 12, and derive their IR excesses. The IRS spectra are analysed with the
newly developed two-layer temperature distribution (TLTD) spectral
decomposition method. For the 7 T Tauri stars with a detected IR excess, we
analyse their solid-state features to derive dust properties such as
mass-averaged grain size, composition and crystallinity. We find a spatial
gradient in the forsterite to enstatite range, with more enstatite present in
the warmer regions. The fact that we see a radial dependence of the dust
properties indicates that radial mixing is not very efficient in the discs of
these young T Tauri stars. The SED analysis shows that the discs in MBM 12, in
general, undergo rapid inner disc clearing, while the binary sources have
faster discevolution. The dust grains seem to evolve independently from the
stellar properties, but are mildly related to disc properties such as flaring
and accretion rates.Comment: 14 pages, accepted by Astronomy and Astrophysic
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