1,350 research outputs found
An Extinction Threshold for Protostellar Cores in Ophiuchus
We have observed continuum emission at lambda = 850 microns over ~4 square
degrees of the Ophiuchus star-forming cloud using SCUBA on the JCMT, producing
a submillimetre continuum map twenty times larger than previous Ophiuchus
surveys. Our sensitivity is 40 mJ/beam, a factor of ~2 less sensitive than
earlier maps. Using an automated identification algorithm, we detect 100
candidate objects. Only two new objects are detected outside the boundary of
previous maps, despite the much wider area surveyed. We compare the
submillimetre continuum map with a map of visual extinction across the
Ophiuchus cloud derived using a combination of 2MASS and R-band data. The total
mass in submillimetre objects is ~ 50 Msun compared with ~ 2000 Msun in
observed cloud mass estimated from the extinction. The submillimetre objects
represent only 2.5% of the cloud mass. A clear association is seen between the
locations of detected submillimetre objects and high visual extinction, with no
objects detected at A_V<7 magnitudes. Using the extinction map, we estimate
pressures within the cloud from P/k ~2x10^5 cm^-3 K in the less-extincted
regions to P/k ~2x10^6 cm^-3 K at the cloud centre. Given our sensitivities,
cold (T_d ~15K) clumps supported by thermal pressure, had they existed, should
have been detected throughout the majority of the map. Such objects may not be
present at low A_V because they may form only where A_V > 15, by some mechanism
(e.g., loss of non-thermal support).Comment: 12 pages, 1 figure. Accepted by Astrophysical Journal Letter
Assessment of shoulder active range of motion in prone versus supine:A reliability and concurrent validity study
Background: As swimming and surfing are prone dominant sports, it would be more sport specific to assess shoulder active range of motion in this position.
Objectives: To determine the reliability of the inclinometer and HALO© for assessing shoulder active range of motion in supine and prone and the concurrent validity of the HALO©. Concurrent validity is based on the comparison of the HALO© and inclinometer. To determine if active range of motion (AROM) differences exists between prone and supine when assessing shoulder internal (IR) and external rotation (ER).
Design: The design included clinical measurement, reliability and validity. Methods: Thirty shoulders (mean age = 26.8 years) without pathology were evaluated. Measurements were taken in supine and prone with both an inclinometer and HALO© device.
Results: Active ER ROM in prone was significantly higher than in supine when using both devices. Intra-rater reliability (within and between session) intraclass correlation coefficient (ICC) values ranged between 0.82–0.99 for both devices in supine and prone. An ICC test revealed a significant (p \u3c 0.01) correlation for both devices in IR and ER movements (ICC3,1 = 0.87 and ICC3,1 = 0.72), respectively.
Conclusion: This study has shown prone assessment of active ER and IR ROM to be a reliable and appropriate method for prone dominant athletes (swimmers and surfers). In this study greater ER ROM was achieved in prone compared to supine. This finding highlights the importance of standardizing the test position for initial and follow up assessments. Furthermore the HALO© and inclinometer have been shown to be reliable tools that show good concurrent validity
Ipsilateral sternoclavicular joint dislocation and fracture of the medial end of the clavicle
The Arab Boycott of Israel: The Role of the United States Antitrust Laws in the Wake of the Export Administration Amendments of 1977
Accelerator performance analysis of the Fermilab Muon Campus
Fermilab is dedicated to hosting world-class experiments in search of new
physics that will operate in the coming years. The Muon g-2 Experiment is one
such experiment that will determine with unprecedented precision the muon
anomalous magnetic moment, which offers an important test of the Standard
Model. We describe in this study the accelerator facility that will deliver a
muon beam to this experiment. We first present the lattice design that allows
for efficient capture, transport, and delivery of polarized muon beams. We then
numerically examine its performance by simulating pion production in the
target, muon collection by the downstream beam line optics, as well as
transport of muon polarization. We finally establish the conditions required
for the safe removal of unwanted secondary particles that minimizes
contamination of the final beam.Comment: 10 p
Correlating Infall with Deuterium Fractionation in Dense Cores
We present a survey of HCO+ (3-2) observations pointed towards dense cores
with previous measurements of N(N2D+)/N(N2H+). Of the 26 cores in this survey,
five show the spectroscopic signature of outward motion, nine exhibit neither
inward nor outward motion, eleven appear to be infalling, and one is not
detected. We compare the degree of deuterium fractionation with infall
velocities calculated from the HCO+ spectra and find that those cores with
[D]/[H] > 0.1 are more likely to have the signature of inward motions than
cores with smaller [D]/[H] ratios. Infall motions are also much more common in
cores with masses exceeding their thermal Jeans masses. The fastest infall
velocity measured belongs to one of the two protostellar cores in our survey,
L1521F, and the observed motions are typically on the order of the sound speed.Comment: Accepted to Ap
The Athletic Profile of Fast Bowling in Cricket : A Review
Cricket is a global sport played in over 100 countries with elite performers attracting multimillion dollar contracts. Therefore, performers maintaining optimum physical fitness and remaining injury free is important. Fast bowlers have a vital position in a cricket team, and there is an increasing body of scientific literature that has reviewed this role over the past decade. Previous research on fast bowlers has tended to focus on biomechanical analysis and injury prevention in performers. However, this review aims to critically analyze the emerging contribution of physiological-based literature linked to fast bowling in cricket, highlight the current evidence related to simulated and competitive in-match performance, and relate this practically to the conditioning coach. Furthermore, the review considers limitations with past research and possible avenues for future investigation. It is clear with the advent of new applied mobile monitoring technology that there is scope for more ecologically valid and longitudinal exploration capturing in-match data, providing quantification of physiological workloads, and analysis of the physical demands across the differing formats of the game. Currently, strength and conditioning specialists do not have a critical academic resource with which to shape professional practice, and this review aims to provide a starting point for evidence in the specific areaPeer reviewedFinal Accepted Versio
- …