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Civilian suicide rates vary by occupation in ways related to occupational stress exposure. Comparable military research finds suicide rates elevated in combat arms occupations. However, no research has evaluated variation in this pattern by deployment history, the indicator of occupation stress widely considered responsible for the recent rise in the military suicide rate.
The joint associations of Army occupation and deployment history in predicting suicides were analysed in an administrative dataset for the 729 337 male enlisted Regular Army soldiers in the US Army between 2004 and 2009.
There were 496 suicides over the study period (22.4/100 000 person-years). Only two occupational categories, both in combat arms, had significantly elevated suicide rates: infantrymen (37.2/100 000 person-years) and combat engineers (38.2/100 000 person-years). However, the suicide rates in these two categories were significantly lower when currently deployed (30.6/100 000 person-years) than never deployed or previously deployed (41.2–39.1/100 000 person-years), whereas the suicide rate of other soldiers was significantly higher when currently deployed and previously deployed (20.2–22.4/100 000 person-years) than never deployed (14.5/100 000 person-years), resulting in the adjusted suicide rate of infantrymen and combat engineers being most elevated when never deployed [odds ratio (OR) 2.9, 95% confidence interval (CI) 2.1–4.1], less so when previously deployed (OR 1.6, 95% CI 1.1–2.1), and not at all when currently deployed (OR 1.2, 95% CI 0.8–1.8). Adjustment for a differential ‘healthy warrior effect’ cannot explain this variation in the relative suicide rates of never-deployed infantrymen and combat engineers by deployment status.
Efforts are needed to elucidate the causal mechanisms underlying this interaction to guide preventive interventions for soldiers at high suicide risk.
The protozoan parasite Toxoplasma gondii is prevalent worldwide and can infect a remarkably wide range of hosts despite felids being the only definitive host. As cats play a major role in transmission to secondary mammalian hosts, the interaction between cats and these hosts should be a major factor determining final prevalence in the secondary host. This study investigates the prevalence of T. gondii in a natural population of Apodemus sylvaticus collected from an area with low cat density (<2·5 cats/km2). A surprisingly high prevalence of 40·78% (95% CI: 34·07%–47·79%) was observed despite this. A comparable level of prevalence was observed in a previously published study using the same approaches where a prevalence of 59% (95% CI: 50·13%–67·87%) was observed in a natural population of Mus domesticus from an area with high cat density (>500 cats/km2). Detection of infected foetuses from pregnant dams in both populations suggests that congenital transmission may enable persistence of infection in the absence of cats. The prevalences of the related parasite, Neospora caninum were found to be low in both populations (A. sylvaticus: 3·39% (95% CI: 0·12%–6·66%); M. domesticus: 3·08% (95% CI: 0·11%–6·05%)). These results suggest that cat density may have a lower than expected effect on final prevalence in these ecosystems.
The Randomized Badger Culling Trial (RBCT) began in 1998 to determine the impact of badger culling in controlling bovine tuberculosis in cattle. A total of 1166 badgers (14% of total) proactively culled during the RBCT were found to be tuberculous, offering a unique opportunity to study the pathology caused by Mycobacterium bovis in a large sample of badgers. Of these, 39% of adults (~6% of all adults culled) had visible lesions (detectable at necropsy) of bovine tuberculosis; cubs had a lower prevalence of infection (9%) but a higher percentage of tuberculous cubs (55·5%) had visible lesions. Only ~1% of adult badgers had extensive, severe pathology. Tuberculous badgers with recorded bite wounds (~5%) had a higher prevalence of visible lesions and a different distribution of lesions, suggesting transmission via bite wounds. However, the predominance of lesions in the respiratory tract indicates that most transmission occurs by the respiratory route.
We are developing Colossal Magnetoresistive (CMR) manganite thin film bolometric sensors to be employed as total energy detectors for beam diagnostics of the Linear Coherent Light Source (LCLS) Free Electron Laser (FEL) (at the Stanford Linear Accelerator). LCLS is an ultra bright, ultra short coherent x-ray source whose peak brightness will exceed that of third generation x-ray sources by about ten orders of magnitude and average brightness by three orders of magnitudes. It is expected to produce 1012 x-rays per 200 fs pulse with a repeat frequency of 120 Hz through self-amplified stimulated emission. In characterizing the beam, it will be necessary to measure the total energy of the FEL pulse. The Advanced Detector Group at Lawrence Livermore Laboratory has developed a scheme for FEL total energy measurements based on bolometric detection and are collaborating with Towson University to implement such a detector using CMR manganite thin films. Here we discuss the basic scheme, results of simulations of the thermal response and the materials development efforts towards fabricating the thin film detectors.
Thin fluorescent organic fibers are used to collect short wavelength sunlight, convert it to longer wavelengths and illuminate photovoltaic (PV) arrays. Using this approach, miniature and lightweight PV arrays have been fabricated. The incoming light is collected by many fibers and mixed before reaching the PV array. Thus homogenous illumination is provided even with partially shadowed fibers, which can cover a large area and can be arranged in a form of a fabric. The PV array itself can be located in any (even dark) place.
In this work we developed and tested high-performance miniature 21 mm2 AlGaAs/GaAs monolithic arrays consisting of 6 cells connected in series. Output electric power density of 75 mW/cm2 and an open-circuit voltage about 6 V was measured outdoors for the arrays integrated with a bundle of 0.25 – 1.00 mm thick polystyrene fibers. The influence of PV array output parameters on the fluorescent fiber diameter, length, as well as on bandgap and design of solar cells is discussed.
Previous epidemiological studies have demonstrated relationships between individual nutrients and glucose intolerance and type 2 diabetes, but the association with the overall pattern of dietary intake has not previously been described. In order to characterize this association, 802 subjects aged 40–65 years were randomly selected from a population-based sampling frame and underwent a 75 g oral glucose-tolerance test. Principal component analysis was used to identify four dietary patterns explaining 31·7 % of the dietary variation in the study cohort. These dietary patterns were associated with other lifestyle factors including socio-economic group, smoking, alcohol intake and physical activity. Component 1 was characterized by a healthy balanced diet with a frequent intake of raw and salad vegetables, fruits in both summer and winter, fish, pasta and rice and low intake of fried foods, sausages, fried fish, and potatoes. This component was negatively correlated with central obesity, fasting plasma glucose, 120 min non-esterified fatty acid and triacylglycerol, and positively correlated with HDL-cholesterol. It therefore appears to be protective for the metabolic syndrome. Component 1 was negatively associated with the risk of having undiagnosed diabetes, and this association was independent of age, sex, smoking and obesity. The findings support the hypothesis that dietary patterns are associated with other lifestyle factors and with glucose intolerance and other features of the metabolic syndrome. The results provide further evidence for the recommendation of a healthy balanced diet as one of the main components of chronic disease prevention.
The ten-fold surface of the decagonal Al72Ni11Co17 (d-Al-Ni-Co) quasicrystal has been investigated using low energy electron diffraction (LEED), spot profile analysis LEED (SPA- LEED), Auger electron spectroscopy (AES) and scanning tunnelling microscopy (STM). This was done as a function of both annealing temperature and annealing time. The long-range order of the surface, as indicated by LEED, increases both as a function of annealing time and temperature. STM shows the surface to be rough and cluster-like at low annealing temperatures (≤725 K), whilst annealing to temperatures in excess of 725 K results in the formation of terraces. These terraces are small (≤ 100 Å width) at lower annealing temperatures and increase in size (100 Å ≤ x ≤ 500 Å) as the annealing temperature is increased (≥ 850 K). They are characterised by the presence of three-fold protrusions which align preferentially. STM images show single height steps as expected due to the periodicity of d-Al-Ni-Co in the z direction. To date it has not been possible to obtain atomic resolution, although this work is continuing.
Age-specific patterns of rotavirus infection were investigated
using a randomly selected and
representative sample of sera from a suburban community of São
Paulo, Brazil screened for
class-specific antibodies to group A rotavirus. Age-serology of anti-rotavirus
primary infection predominant in young infants with a median age of around
consistent with IgM serology suggesting highest rates of recent infection
between ages 4 and 48
months. Anti-rotavirus serum IgA prevalence increased gradually with age.
from infants, collected 1 month apart, indicated high exposure rates with
occurring in several infants during the reported low transmission season.
Between 5 and 10%
of adults had elevated IgM levels indicative of recent infection and, potentially,
important contribution adults may play to rotavirus transmission. Further
understanding of the
dynamics of rotavirus transmission within populations, at group and serotype
benefit the design and monitoring of future immunization programmes.
Remifentanil is an ultrashort acting mu opioid, well suited to total intravenous (i.v.) anaesthesia. Pain immediately following emergence from anaesthesia is a potential problem because of the rapid offset. This study investigated the transition from remifentanil/propofol total intravenous anaesthesia to post-operative analgesia with epidural or patient controlled analgesia morphine in 22 patients undergoing major abdominal surgery. A remifentanil post-operative infusion initiated during emergence was titrated in the recovery room for 30 min, at which time 14% of patients had a pain score of 2 and 86% had pain scores of 0 or 1 (0 = no pain; 1 = mild pain; 2 = moderate pain; 3 = severe pain), at a mean infusion rate of 0.086 mug kg −1 min −1 . A smooth transition was then made to either epidural analgesia or patient controlled analgesia with morphine; pain scores were not significantly changed during the transition. Nausea occurred in 16 of the 22 patients, but only following administration of morphine. Epidural analgesia produced significantly lower pain scores on the surgical ward compared with patient controlled analgesia.
Progress on mid-infrared photodetectors fabricated by the liquid phase epitaxial growth of GaInAsSb, InAsSbP, and AlGaAsSb on GaSb and InAs substrates is reported. GaInAsSb p/n and p-i-n detectors, InAsSbP p/n detectors and AlGaAsSb/GaInAsSb avalanche photodiode (APD) structures were fabricated. Preliminary results indicate that these devices can have higher detectivity with lower cooling requirements than commercially available detectors in the same wavelength range. Infrared p/n junction detectors made from GaInAsSb and InAsSbP showed cut-off wavelengths of 2.3.μm and 2.8. μm respectively. Room temperature background noiselimited detectivity (D*BLIP) of 4 × 1010 cmHz1/2/W for GaInAsSb detectors and 4 × 108 cmHz1/2/W for InAsSbP was measured. Room-temperature avalanche multiplication gain of 20 was measured on AlGaAsSb/GaInAsSb avalanche photodiodes.
The response of a range of porous Si and poly Si films to storage in acellular simulated body fluids is summarised and its implications discussed. It is suggested that the combination of VLSI technology, micromachining and surface microstructuring achievable with silicon, could establish this prominent semiconductor as a very useful biomaterial by the next century. The ‘biocompatibility’ of a variety of silicon microstructures, and even bulk silicon has received surprisingly little study, but now warrants detailed in-vitro and in-vivo assessment.
The crystallography and electronic properties of the Ln2-xSr1+xMn2O7 manganese oxides adopting the n = 2 Ruddlesden-Popper (RP) structure are discussed, focusing on the structural phase diagrams and electronic properties in the vicinity of the Mn +3.5 oxidation state and in particular the ease of synthesis of single phases of these materials.
The full spectrum of occupied and unoccupied σ and Π orbitals is presented for solid C60, C70, and graphite, using C1s emission and absorption spectroscopy. There are significant differences between C60 and C70, and even larger changes relative to their infinite analog graphite C∞. A comparison is made with photoemission and inverse photoemission results, along with first principles quasiparticle calculations.
This is the concluding part of a series of three papers for this Journal, documenting the European studies into the feasibility of 1000 ft vertical separation minima above FL290. This paper outlines the results from European data collections other than the main precision radar data collection and expands upon the factors affecting height-keeping performance. The development of a Minimum Altimetry System Performance Specification (MASPS), necessary for a reduced vertical separation minimum above FL29O, is presented. A number of implementation issues, in particular monitoring, are also discussed.
The contents of this paper reflect the views of the authors; they do not necessarily reflect the official views or policy of the NLR, CAA or EUROCONTROL.
Resonance-enhanced multiphoton ionization (REMPI) has been used to detect the methyl radical CH3 within 0.5 mm of the substrate during CVD diamond growth. A strong dependence of the CH3 REMPI signal near the surface on substrate temperature is observed, which is not seen further from the surface. Below 1000 K, the observed temperature dependence may be characterized by an activation energy of approximately 4 ± 1 kcal/mole. The cause of the methyl depletion at low temperatures is not yet clear, but may be due to either gas-phase recombination near the surface or surface chemistry. The same qualitative behavior is observed for different substrate-filament distances and for gas compositions from 0.5% to 5% CH4 in H2.