14,310 research outputs found
Initial subjective load carriage injury data collected by interviews and questionnaires
This study aimed to identify the types, incidence, and causes of any potential load carriage injuries or discomfort as a result of a 2-hour, forced-speed, treadmill march carrying 20 kg. Subjective load carriage data were collected, through both interviews and questionnaires, from relatively inexperienced soldiers after a period of load carriage. Results from the study showed that the upper limb is very susceptible to short-term discomfort, whereas the lower limb is not. The shoulders were rated significantly more uncomfortable then any other region, and blisters were experienced by ∼60% of participants. Shoulder discomfort commences almost as soon as the load is added and increases steadily with time; however, foot discomfort increases more rapidly once the discomfort materializes. In conclusion, early development of shoulder pain or blisters may be a risk factor for severe pain or noncompletion of a period of prolonged load carriage
Entropy and entanglement bounds for reduced density matrices of fermionic states
Unlike bosons, fermions always have a non-trivial entanglement. Intuitively,
Slater determinantal states should be the least entangled states. To make this
intuition precise we investigate entropy and entanglement of fermionic states
and prove some extremal and near extremal properties of reduced density
matrices of Slater determinantal states.Comment: 20 pages. This version of the paper is a substantial revision of the
previous versio
The effect of military load carriage on ground reaction forces
Load carriage is an inevitable part of military life both during training and operations. Loads carried are frequently as high as 60% bodyweight, and this increases injury risk. In the military, load is carried in a backpack (also referred to as a Bergen) and webbing, these combined form a load carriage system (LCS). A substantial body of literature exists recording the physiological effects of load carriage; less is available regarding the biomechanics. Previous biomechanical studies have generally been restricted to loads of 20% and 40% of bodyweight, usually carried in the backpack alone. The effect of rifle carriage on gait has also received little or no attention in the published literature. This is despite military personnel almost always carrying a rifle during load carriage. In this study, 15 male participants completed 8 conditions: military boot, rifle, webbing 8 and 16 kg, backpack 16 kg and LCS 24, 32 and 40 kg. Results showed that load added in 8 kg increments elicited a proportional increase in vertical and anteroposterior ground reaction force (GRF) parameters. Rifle carriage significantly increased the impact peak and mediolateral impulse compared to the boot condition. These effects may be the result of changes to the vertical and horizontal position of the body's centre of mass, caused by the restriction of natural arm swing patterns. Increased GRFs, particularly in the vertical axis, have been positively linked to overuse injuries. Therefore, the biomechanical analysis of load carriage is important in aiding our understanding of injuries associated with military load carriage
Strengthening the Campus Leadership Team through Effective Principal and Counselor Relationships: Implications for Training
Campuses with successful leadership teams have a better opportunity to meet the ever-increasing and complex needs of the students they serve (Crowther, Kaagan, Ferguson, & Hann, 2002). These successful campuses are strengthened when they include strong principals and counseling teams with shared mutual trust and understanding that permeates the school climate (DeVoss & Andrews, 2006). A review of the literature revealed a paucity of studies examining the nature of successful principal-counselor relations and the impact of this relationship on student success, effective campus leadership teams, and an effective school climate that promotes learning. Meaningful dialogue and discussion of this critical professional relationship also were found lacking in the major counseling and educational leadership professional journals
Diverse Long-Term Variability of Five Candidate High-Mass X-ray Binaries from Swift Burst Alert Telescope Observations
We present an investigation of long-term modulation in the X-ray light curves
of five little-studied candidate high-mass X-ray binaries using the Swift Burst
Alert Telescope. IGR J14488-5942 and AX J1700.2-4220 show strong modulation at
periods of 49.6 and 44 days, respectively, which are interpreted as orbital
periods of Be star systems. For IGR J14488-5942, observations with Swift X-ray
Telescope show a hint of pulsations at 33.4 s. For AX J1700.2-4220, 54 s
pulsations were previously found with XMM. Swift J1816.7-1613 exhibits
complicated behavior. The strongest peak in the power spectrum is at a period
near 150 days, but this conflicts with a determination of a period of 118.5
days by La Parola et al. (2014). AX J1820.5-1434 has been proposed to exhibit
modulation near 54 days, but the extended BAT observations suggest modulation
at slightly longer than double this at approximately 111 days. There appears to
be a long-term change in the shape of the modulation near 111 days, which may
explain the apparent discrepancy. The X-ray pulsar XTE J1906+090, which was
previously proposed to be a Be star system with an orbital period of ~30 days
from pulse timing, shows peaks in the power spectrum at 81 and 173 days. The
origins of these periods are unclear, although they might be the orbital period
and a superorbital period respectively. For all five sources, the long-term
variability, together with the combination of orbital and proposed pulse
periods, suggests that the sources contain Be star mass donors.Comment: Accepted for publication in The Astrophysical Journal. 15 pages, 27
figures. (v2 corrects citation
Three Models of Retirement: Computational Complexity Versus Predictive Validity
Empirical analysis often raises questions of approximation to underlying individual behavior. Closer approximation may require more complex statistical specifications, On the other hand, more complex specifications may presume computational facility that is beyond the grasp of most real people and therefore less consistent with the actual rules that govern their behavior, even though economic theory may push analysts to increasingly more complex specifications. Thus the issue is not only whether more complex models are worth the effort, but also whether they are better. We compare the in-sample and out-of-sample predictive performance of three models of retirement -- "option value," dynamic programming, and probit -- to determine which of the retirement rules most closely matches retirement behavior in a large firm. The primary measure of predictive validity is the correspondence between the model predictions and actual retirement under the firm's temporary early retirement window plan. The "option value" and dynamic programming models are considerably more successful than the less complex probit model in approximating the rules individuals use to make retirement decisions, but the more complex dynamic programming rule approximates behavior no better than the simpler option value rule.
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