50 research outputs found
Development of a valid simulation assessment for a military dismounted assault task
The Australian Defence Force is currently developing physical standards commensurate with job demands. Vital to this development process has been the accurate profiling of common military tasks. One such task required of all dismounted combat soldiers, an offensive assault on an enemy force, was the subject of in-depth profiling. In addition to overall assault performance, potential differences among patrol roles (scout, gunner, and flank) were investigated. Three different mock assaults of 100 to 150 m were performed by three patrols comprising qualified experienced infantry soldiers. Each soldier was fitted with a heart rate monitor and wore a global positioning device. Average assault duration was 6.5 minutes and required nineteen 7-m bounds performed on a 22-seconds duty cycle at 75% heart rate reserve and a work to rest ratio 1:4. Assaults conducted in more densely vegetated terrain resulted in significantly reduced (p \u3c 0.05) bound distance, bound duration, and movement velocity. Results indicated significant performance differences (p \u3c 0.05) among patrol roles for external load carried, heart rate response, bound duration, and distance covered while movement velocity was not different (p \u3e 0.05). As a result of profiling the assault task, a valid simulation capable of assessing soldiers\u27 physical capacity to perform this task was developed
Resting toucher: a time and motion analysis of elite lawn bowls
Whilst numerous investigations have explored the physical demands placed upon competitive sportspeople from a wide array of sports little is known about the physical demands placed on lawn bowlers. The purpose of this study was to ascertain the movement activities of Australian representative singles and pairs players and to determine the frequency and duration of these activities. One match each of two male and two female players (one singles and one pairs player per gender) were videotaped during an international tournament. During playback of the videotaped matches (n = 4), a single observer coded the players’ activities into five distinct categories (waiting, walking forward, walking backward, jogging and bowling) using a computerised video editing system (Gamebreaker™ Digital Video Analysis System). Field calibration of players over 30m for forward motions and 15m for the backward motion was performed to allow for the estimation of total distance covered during the match. Heart rate was monitored during each match. The duration of a match was found to be (mean ± SD) 1hr 28 ± 15mins. The total distance covered during each match was 2093 ± 276m. The mean percentage of match time spent in each motion was: waiting, 61.8 ± 9.3%; walking forward, 22.3 ± 5.6%; walking backward, 2.0 ± 0.4%; jogging, 1.1 ± 0.5%; and bowling, 8.5 ± 4.2%. Average heart rate was found to be 57 ± 7% of age-predicted HRmax with a maximum of 78 ± 9% of age-predicted HRmax. The results of this study suggest that playing lawn bowls at an international level requires light-moderate intensity activity similar to that reported for golf
A quantification of the physiological demands of the army emergency responder in the Australian Army
The Australian Defence Force is reviewing the physical demands of all employment categories in the Australian Army to establish valid and legally defensible assessments. The current assessments, performed in physical training attire, are not specific to job demands. Moreover, the fitness standards decrease based on age and are lower for females, and as job requirements are constant, these assessments are counterintuitive. With regard to the Army Emergency Responder employment category, tasks of physical demand in the present study were selected through consultation with subject-matter experts. Participants consisted of 10 qualified Army Emergency Responder soldiers and three noncareer firefighters under instruction. Real-life firefighting scenarios were witnessed by researchers and helped form task simulations allowing measurement of heart rate and oxygen consumption. Peak oxygen consumption ranged from 21.8 ± 3.8 to 40.0 ± 3.4 mL kg−1 min−1 during cutting activities and a search and rescue task, respectively, representing values similar to or higher than the current entry standards. Manual handling tasks were also assessed, with the heaviest measured being two soldiers lifting a 37.7-kg Utility Trunk to 150 cm. The findings provide a quantitative assessment of the physiological demands of Army Emergency Responders, and highlight the need for change in current fitness assessments
Black Holes in Pseudobulges and Spheroidals: A Change in the Black Hole-Bulge Scaling Relations at Low Mass
We investigate the relationship between black hole mass and host galaxy
properties for active galaxies with the lowest black hole masses currently
known in galaxy nuclei. Hubble Space Telescope imaging confirms that the host
galaxies have correspondingly low luminosity; they are ~1 mag below L*. In
terms of morphology, ~60% of the members of the sample are disk-dominated, and
all of these are consistent with containing a bulge or (more likely)
pseudobulge, while the remainder are compact systems with no discernible disk
component. In general the compact components of the galaxies do not obey the
fundamental plane of giant elliptical galaxies and classical bulges, but rather
are less centrally concentrated at a given luminosity, much like spheroidal
galaxies. Our results strongly confirm that a classical bulge is not a
requirement for a nuclear black hole. At the same time, the observed ratio of
black hole to bulge mass is nearly an order of magnitude lower in this sample
than that seen for classical bulges. While the M-sigma relation appears to
continue to low mass, it seems that black hole-galaxy scaling relations do
depend on galaxy structure.Comment: to appear in ApJ; 22 pages; 8 figures; original version available at
http://www.astro.princeton.edu/~jgreene/paper.pd
The Lick AGN Monitoring Project: Alternate Routes to a Broad-line Region Radius
It is now possible to estimate black hole masses across cosmic time, using
broad emission lines in active galaxies. This technique informs our views of
how galaxies and their central black holes coevolve. Unfortunately, there are
many outstanding uncertainties associated with these "virial" mass estimates.
One of these comes from using the accretion luminosity to infer a size for the
broad-line region. Incorporating the new sample of low-luminosity active
galaxies from our recent monitoring campaign at Lick Observatory, we
recalibrate the radius-luminosity relation with tracers of the accretion
luminosity other than the optical continuum. We find that the radius of the
broad-line region scales as the square root of the X-ray and Hbeta
luminosities, in agreement with recent optical studies. On the other hand, the
scaling appears to be marginally steeper with narrow-line luminosities. This is
consistent with a previously observed decrease in the ratio of narrow-line to
X-ray luminosity with increasing total luminosity. The radius of the broad-line
region correlates most tightly with Hbeta luminosity, while the X-ray and
narrow-line relations both have comparable scatter of a factor of two. These
correlations provide useful alternative virial BH masses in objects with no
detectable optical/UV continuum emission, such as high-redshift galaxies with
broad emission lines, radio-loud objects, or local active galaxies with
galaxy-dominated continua.Comment: 8 pages, 1 figure, accepted for publication in Ap
The Hubble Space Telescope Wide Field Camera 3 Early Release Science data: Panchromatic Faint Object Counts for 0.2-2 microns wavelength
We describe the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) Early
Release Science (ERS) observations in the Great Observatories Origins Deep
Survey (GOODS) South field. The new WFC3 ERS data provide calibrated, drizzled
mosaics in the UV filters F225W, F275W, and F336W, as well as in the near-IR
filters F098M (Ys), F125W (J), and F160W (H) with 1-2 HST orbits per filter.
Together with the existing HST Advanced Camera for Surveys (ACS) GOODS-South
mosaics in the BViz filters, these panchromatic 10-band ERS data cover 40-50
square arcmin at 0.2-1.7 {\mu}m in wavelength at 0.07-0.15" FWHM resolution and
0.090" Multidrizzled pixels to depths of AB\simeq 26.0-27.0 mag (5-{\sigma})
for point sources, and AB\simeq 25.5-26.5 mag for compact galaxies.
In this paper, we describe: a) the scientific rationale, and the data taking
plus reduction procedures of the panchromatic 10-band ERS mosaics; b) the
procedure of generating object catalogs across the 10 different ERS filters,
and the specific star-galaxy separation techniques used; and c) the reliability
and completeness of the object catalogs from the WFC3 ERS mosaics. The
excellent 0.07-0.15" FWHM resolution of HST/WFC3 and ACS makes star- galaxy
separation straightforward over a factor of 10 in wavelength to AB\simeq 25-26
mag from the UV to the near-IR, respectively.Comment: 51 pages, 71 figures Accepted to ApJS 2011.01.2
The Epoch of Disk Settling: z~1 to Now
We present evidence from a sample of 544 galaxies from the DEEP2 Survey for
evolution of the internal kinematics of blue galaxies with stellar masses
ranging 8.0 < log M* (M_Sun) < 10.7 over 0.2<z<1.2. DEEP2 provides galaxy
spectra and Hubble imaging from which we measure emission-line kinematics and
galaxy inclinations, respectively. Our large sample allows us to overcome
scatter intrinsic to galaxy properties in order to examine trends in
kinematics. We find that at a fixed stellar mass galaxies systematically
decrease in disordered motions and increase in rotation velocity and potential
well depth with time. Massive galaxies are the most well-ordered at all times
examined, with higher rotation velocities and less disordered motions than less
massive galaxies. We quantify disordered motions with an integrated gas
velocity dispersion corrected for beam smearing (sigma_g). It is unlike the
typical pressure-supported velocity dispersion measured for early type galaxies
and galaxy bulges. Because both seeing and the width of our spectral slits
comprise a significant fraction of the galaxy sizes, sigma_g integrates over
velocity gradients on large scales which can correspond to non-ordered gas
kinematics. We compile measurements of galaxy kinematics from the literature
over 1.2<z<3.8 and do not find any trends with redshift, likely for the most
part because these datasets are biased toward the most highly star-forming
systems. In summary, over the last ~8 billion years since z=1.2, blue galaxies
evolve from disordered to ordered systems as they settle to become the
rotation-dominated disk galaxies observed in the Universe today, with the most
massive galaxies being the most evolved at any time.Comment: submitted to ApJ and responded to referee repor
Pneumonia Incidence and Mortality in Mainland China: Systematic Review of Chinese and English Literature, 1985–2008
BACKGROUND: Pneumonia is a leading infectious disease killer worldwide, yet the burden in China is not well understood as much of the data is published in the non-English literature. METHODOLOGY/PRINCIPAL FINDINGS: We systematically reviewed the Chinese- and English-language literature for studies with primary data on pneumonia incidence and mortality in mainland China. Between 1985 and 2008, 37 studies met the inclusion criteria. The quality of the studies was highly variable. For children <5 years, incidence ranged from 0.06-0.27 episodes per person-year and mortality ranged from 184-1,223 deaths per 100,000 population. Overall incidence and mortality were stable or decreased over the study period and were higher in rural compared to urban areas. CONCLUSIONS/SIGNIFICANCE: Pneumonia continues to be a major public health challenge in young children in China, and estimates of pneumonia incidence and mortality vary widely. Reliable surveillance data and new prevention efforts may be needed to achieve and document additional declines, especially in areas with higher incidence and mortality such as rural settings
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead