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The mental health outcomes of military personnel deployed on peacekeeping
missions have been relatively neglected in the military mental health
To assess the mental health impacts of peacekeeping deployments.
In total, 1025 Australian peacekeepers were assessed for current and
lifetime psychiatric diagnoses, service history and exposure to
potentially traumatic events (PTEs). A matched Australian community
sample was used as a comparator. Univariate and regression analyses were
conducted to explore predictors of psychiatric diagnosis.
Peacekeepers had significantly higher 12-month prevalence of
post-traumatic stress disorder (16.8%), major depressive episode (7%),
generalised anxiety disorder (4.7%), alcohol misuse (12%), alcohol
dependence (11.3%) and suicidal ideation (10.7%) when compared with the
civilian comparator. The presence of these psychiatric disorders was most
strongly and consistently associated with exposure to PTEs.
Veteran peacekeepers had significant levels of psychiatric morbidity.
Their needs, alongside those of combat veterans, should be recognised
within military mental health initiatives.
The Coconino Sandstone is a Permian deposit of cross-bedded sandstone which is distributed over much of northern Arizona. Vertebrate fossil trackways are abundant in the Coconino Sandstone, and invertebrate trackways are present but less abundant. No other fossils have been found in this formation.
A number of papers dealing with the systematics and paleoecology of these tracks have been published, but underprints have not previously been reported from the Coconino Sandstone. A slab from north of Seligman, Arizona bears intersecting trackways of an invertebrate and two tetrapods. A portion of the slab contains the surface on which the animals were walking. On the remainder of the slab a thin layer bearing that upper surface has broken away to reveal another surface with well preserved underprints of both invertebrates and tetrapods (systematic and behavioral aspects of these trackways will be described in a separate paper).
The underprints are very distinct, deep depressions with uniformly rounded edges, while the original tracks are shallower and much less distinct because some sand slumped into them. It appears that as the animal lifted its foot out of a track the sand partly filled in the depression, but in underlying laminae the contour of the underprint was protected by the sand pushed down from above by the animal's foot.
Comparison of this slab with other fossil trackways from the Coconino Sandstone suggests that a number of these trackways may be underprints. Evidence favoring that interpretation are the clarity and depth of the footprints and their uniformly rounded edges. This interpretation also suggests an explanation for some footprints that are so deep that the sand on the front edge of the track overhangs the footprint impression. The Coconino Sandstone is composed of fine sand and does not show evidence of clays or other material that could provide the cohesion to retain such steep, even overhanging, surfaces. If these footprints are underprints, the deep, undercut impressions may have been preserved by the continuity of the overlying laminae while the surface depressions were partly filled by slumping sand.
It might be expected that underprints would be less distinct and detailed than the actual print. That may be true for tracks made in a substrate with an ideal consistency for preserving the tracks, but in pure, fine sand slumping of sand at the surface can apparently obliterate footprint details that are preserved in the underprints.
In this work we explore the radiocarbon (14C) signal as an independent tool to assess the year of formation of individual tree rings of tropical species in northern Brazil. Three different species were analyzed in this work: Dipteryx magnifica, Enterolobium maximum, and Hymenolobium petraeum. The studied samples are from the stem of only one individual of each species, all cut down in 2008 in Porto Trombetas, Pará, Brazil. Individual tree rings were identified based on wood anatomy and they were counted from bark to pith. Several rings were selected for 14C analysis in order to cover the overall shape of the 14C atmospheric bomb peak (after 1955). The 14C content was measured at Laboratory of Radiocarbon, Universidade Federal Fluminense (LAC-UFF). Results are compared with the Southern Hemisphere 14C atmospheric calibration curves. For E. maximum and H. petraeum the 14C signal exhibits an overall good match with the SH zone 3 and suggests annual seasonality in the growth-ring formation. These species offer suitable characteristics for dendrochronology. The D. magnifica shows mismatches in the 14C measurements that are likely a result of difficulties in identifying ring boundaries with certainty. Additional techniques may be helpful to disentangle the origin of this discrepancy.
Rotational grazing (RG) is a livestock management practice that rotates grazing cattle on a scale of hours to days among small pastures termed paddocks. It may beneficially affect stream channels, relative to other livestock management practices. Such effects and other beneficial effects on hydrology are important to RG's potential to provide a highly multifunctional mode of livestock farming. Previous comparisons of effects of RG and confinement dairy (CD) on adjoining streams have been restricted in scale and scope. We examined 11 stream-channel characteristics on a representative sample of 37 small dairy farms that used either RG or CD production methods. Our objectives were: (1) to compare channel characteristics on RG and CD farms, as these production methods are implemented in practice, in New York, Pennsylvania and Wisconsin, USA; and (2) to examine land use on these farms that may affect stream-channel characteristics. To help interpret channel characteristic findings, we examined on-farm land use in riparian areas 50 m in width along both sides of stream reaches and whole-farm land use. In all states, stream-channel characteristics on RG and CD farms did not differ. Whole-farm land use differed significantly between farm types; CD farms allocated more land to annual row crops, whereas RG farms allocated more land to pasture and grassland. However, land cover in 50 m riparian areas was not different between farm types within states; in particular, many RG and CD farms had continuously grazed pastures in riparian areas, typically occupied by juvenile and non-lactating cows, which may have contributed sediment and nutrients to streams. This similarity in riparian management practices may explain the observed similarity of farm types with respect to stream-channel characteristics. To realize the potential benefits of RG on streams, best management practices that affect stream-channel characteristics, such as protection of riparian areas, may improve aggregate effects of RG on stream quality and also enhance other environment, economic and social benefits of RG.
Piglet birth weight and litter uniformity are important for piglet survival. Insulin-stimulating sow diets before mating may improve subsequent piglet birth weights and litter uniformity, but the physiological mechanisms involved are not clear. This study evaluated effects of different levels of insulin-stimulating feed components (dextrose plus starch; fed twice daily) during the weaning-to-estrus interval (WEI) on plasma insulin and IGF-1 concentrations, and on follicle development and subsequent luteal, fetal and placental development and uniformity at days 42 to 43 of pregnancy. During WEI, multiparous sows were isocalorically fed diets supplemented with 375 g/day dextrose plus 375 g/day corn starch (INS-H), with 172 g/day dextrose plus 172 g/day corn starch and 144 g/day animal fat (INS-L), or with 263 g/day animal fat (CON). Jugular vein catheters were inserted through the ear vein at 1.5 days before weaning to asses plasma insulin and IGF-1 concentrations. After estrus, all sows received a standard gestation diet until slaughter at days 42 to 43 of pregnancy. The dextrose plus starch-diets enhanced the postprandial insulin response in a dose-dependent manner (e.g. at day 2 insulin area under the curve was 4516 μU/444 min for CON, 8197 μU/444 min for INS-L and 10 894 μU/444 min for INS-H; s.e.m. = 694; P < 0.001), but did not affect plasma IGF-1 concentrations during the first 3 days of WEI. Follicle development and subsequent luteal, fetal and placental development and uniformity were not affected by the dietary treatments, nor related to plasma insulin and IGF-1 concentrations during WEI. Pre-weaning plasma insulin and IGF-1 concentrations were negatively related to sow body condition loss during lactation, but were not related to subsequent reproduction characteristics. This study shows that dietary dextrose plus starch are effective in stimulating insulin secretion (both postprandial peak and long-term concentration), but not IGF-1 secretion during the first 3 days after weaning in multiparous sows. The extreme insulin-stimulating diets during WEI did, however, not improve follicle development, or subsequent development and uniformity of fetuses and placentas in these high-prolific sows (27.0 ± 0.6 ovulations; 18.6 ± 0.6 vital fetuses).
Spectra from 1 to 2·5 μm, at 230–430 spectral resolution, are presented of the fluorescent molecular hydrogen line emission from two locations in the reflection nebula NGC 2023. Over 100 H2 lines can be identified in the spectra, although blending and poor atmospheric transmission mean that reliable level column densities can only be obtained from 35 lines. This latter group includes lines from v = 1–8 and v = 10, spanning an energy range from 6000 to 45,000 K above the ground state. These data may be used to constrain models of photodissociation regions and of fluorescent excitation for molecular hydrogen.
The development of lower-glycaemic index (GI) foods requires simple, palatable and healthy strategies. The objective of the present study was to determine the most effective dose of a novel viscous fibre supplement (PGX®) to be added to starchy foods to reduce their GI. Healthy subjects (n 10) consumed glucose sugar (50 g in water × 3) and six starchy foods with a range of GI values (52–72) along with 0 (inert fibre), 2·5 or 5 g granular PGX® dissolved in 250 ml water. GI testing according to ISO Standard 26 642-2010 was used to determine the reduction in GI. PGX® significantly reduced the GI of all six foods (P < 0·001), with an average reduction of 19 % for the 2·5 g dose and 30 % for the 5 g dose, equivalent to a reducing the GI by 7 and 15 units, respectively. Consuming small quantities of the novel functional fibre PGX®, mixed with water at the start of a meal, is an effective strategy to reduce the GI of common foods.
New abrasive particles based on SiO2 and Al2O3 were produced with different coating and doping. Seven specifically designed particles were dispersed to prepare slurries for Cu CMP. Glycin was used as complexing agent and hydrogenperoxid as oxidizer. The experimentally obtained removal rate, selectivity, surface quality and planarisation ability, demonstrate a significant impact of the different abrasives tested. SiO2 particles covered with Al2O3 increased the removal rate for Cu. In comparison to this behavior, a low rate for TaN proved a high selectivity copper removal required by the Cu CMP process. A new method for the planarisation length monitoring (step polish response) shows also significant differences in planarisation length (PL) by the polish of copper with slurries composed of these new particles.
Thin alumina films are grown on a silicon substrate, in vacuum, at a rate of about 10 Å per second, and at substrate temperatures below 1500C. Alumina is dissolved in supercritical water and the resulting solution expanded in a supersonic free jet, which is directed at the substrate. The films are characterized by ESCA and FTIR.
Zirconium nitride films on silicon substrates have been prepared by DC magnetron enhanced reactive sputtering in a N2/Ar gas mixture under various experimental conditions. The films properties (chemical composition, structure, morphology and optical response) were investigated and related to the experimental conditions. It is shown that these properties are strongly related to the target current density which governs the deposition rate, to the deposit thickness, to the nitrogen partial pressure and to the residual gas contamination. The objective of this paper is to detect the minimum film thickness threshold under which a zirconium nitride coating cannot be used in decorative applications.
Background impurities and the resulting electrical characteristics were studied for GaN wafers grown using hydride vapor phase epitaxy at various growth conditions. The electron concentration was found to decrease with increasing GaN thickness, by orders of magnitude in the first few microns of growth, but continuing gradually for thousands of microns. Physical removal of the backside degenerate layer enabled improved analysis of the electrical properties. Secondary ion mass spectroscopy was used to determine that the presence of oxygen and silicon accounted for the electron concentration for unintentionally n-type doped material. The concentration of oxygen was found to vary more than that of silicon and increased with decreasing growth temperature. The resistivity was measured to be as high as 1 ohm-cm, corresponding to a carrier concentration of 1016 cm−3. Iron was demonstrated to effectively compensate the residual donors and increased the resistivity to greater than 109 ohm-cm at room temperature and greater than 3×105 ohm-cm at 250 °C. An activation energy for the iron-doped GaN was determined by variable temperature resistivity measurements to be 0.51 eV.
Delta doping (paused growth doping) was investigated as an alternative to uniformly distributing the dopant in the nitride semiconductor layer. In this work, delta doped layers were produced in MOVPE-grown AlGaN and GaN layers at a susceptor temperature of 1220°C by turning off the group III precursors (TMG and TMA) and introducing into the reactor a silicon precursor Si2H6 (disilane) for a fixed period (pause time) before growth was restarted. The compositional and electrical properties as a function of aluminum content and dopant flux were investigated for nitride layers on 2 inch c-plane sapphire substrates. Secondary ion mass spectroscopy (SIMS) measurements revealed a sharp silicon peak with a FWHM of 5.7 ± 0.6 nm for an Al0.25Ga0.75N sample and 10.0 ± 0.6 nm for a GaN sample with sheet charges of 7.9×1012 cm−2 and 9.9×1012 cm−2,respectively. Room temperature Hall mobility as high as 265 cm2 V−1s−1 for a sheet charge 7.9×1012 cm−2 was demonstrated for delta doped Al0.25Ga0.75N layers, but the mobility enhancement saturated and then decreased with increasing sheet charge. Room temperature sheet charge increased with increasing dopant flux for delta-doped AlGaN and GaN layers. Sheet charge density as high as 2.2×1013 cm−2 and 1.3×1013 cm−2 was measured at room temperature for Al0.25Ga0.75N and GaN delta doped layers, respectively. Under identical doping conditions, the Hall sheet charge of the delta doped Al0.25Ga0.75N layer was approximately half as large as GaN layers. The impurity and electrical characteristics of the delta doped layers are further discussed.
In electronic circuits besides active devices a major part of the components are discrete passive components such as capacitors, resistors and inductors. Especially in the telecommunication circuits, miniaturisation is a major issue. To achieve a high degree of miniaturisation of passive components, thin film processes have been applied. A thin film module for high frequency applications has been demonstrated with a three-dimensional integration of a thin film resistor, a thin film X7R capacitor and a thin film NP0 capacitor processed on top of each other.
A vacuum microelectronic device containing carbon nanotube electron field-emitters was developed and tested. The gated cathode was fabricated using conventional microelectronics fabrication techniques and a final, self-aligned, in situ carbon nanotube growth step. To our knowledge, this is the first vacuum microelectronics device with carbon nanotube field-emitters grown in situ with a catalytic growth process. The turn-on voltage of the cathode was less than 20 volts and the emission current density at 50 volts was as high as 9 mA-cm−2. The fabrication process, device performance, manufacturing issues and cathode applications will be discussed.
It is well known and accepted that the viscosity of CMP-slurries has an effect on polishing results. Even though the literature on rheology recognizes that viscosity is not always constant and the slurry can show non-Newtonian behavior or even dilatant effects, all calculations have been performed with constant viscosity.
However, the “real” viscosity of a CMP-slurry during polishing can change significantly with shear rate.
The typical equipment for viscosity measurement is based on a rotating cylinder or a plate. But even with a plate system it is only possible to reach a shear rate range up to 50,000 1/sec. A calculation of the shear rate between the wafer and the polishing pad is based on a relative velocity of 1 m/sec and a distance between the wafer and the pad of 20 μm; this correlates to a shear rate of 50,000 1/sec. If parts of the polishing pad come closer to the wafer or especially closer to the edge of structures on the wafer (for example 1 μm), the shear rate will increase locally to 1,000,000 1/sec.
When the shear rate is high enough, viscosity depends mostly on hydrodynamic factors like viscosity of continuos phase, solids content, particle size, particle size distribution and shape of the particles.
The shape of fumed metal oxides is controlled during the synthesis in the flame process. But the slurry-making process is also responsible for particle size distribution, shape of the particle and the high shear rate viscosity of the CMP-slurry.
The high shear rate viscosity of different silica slurries in dependence from BET-surface area, used milling energy, concentration and preparation direction was measured in this investigation.
We investigated the ultrastructure of the modern calcitic brachiopods Megerlia truncata (Linnaeus) and Terebratalia transversa (Sowerby) with SEM, electron backscattering diffraction and microhardness indentation. The outer, primary shell layer can be regarded as a nanocrystalline thin film that forms a hard protective coating around the inner, much softer secondary layer that can be expressed as an inorganic/organic fibre composite. The fibrous, curved growth of the secondary shell layer crystals occurs in arbitrary directions perpendicular to the <0 0 0 1> triad symmetry direction of calcite and is most likely obtained by simple confinement to a protein sheath rather than by biomolecular adsorbates blocking growth of any specific crystal face. The curvature of the fibres is caused by rearrangements of the secreting cell array during growth, whereby the existing crystal lattice is not distorted. It serves as a substrate for continued crystal growth. Thus biologically mediated calcite crystallization is a purposeful process and seems to be significantly different to the inorganic crystallization of calcite.
In this paper, we report the electrical and optical characteristics of Si delta-doped AlGaN cladding layers, p-cladding structure optimization and the impact on the efficiency of 340nm AlGaN UV LEDs. Compared to the uniformly doped n-AlGaN layer, adding Si Δ-doping layers reduced the sheet resistance by improving both the Hall mobility and carrier concentration. Increasing the number of Si Δ-doped layers further lowered the sheet resistance without cracking the material. The Δ-doped layers in n-Al0.3Ga0.7N improved the optical properties by enhancing near band edge emission as much as 2-fold relative to deep level emission. Additionally, Δ-doping in n-AlGaN layers had no detrimental effect on the optical transparency of the LEDs. The p-cladding layer was found to have a strong absorption at 340nm. Reducing the p-GaN cap layer from 35nm to 10nm tripled the light emission intensity. By optimizing the n- and p-AlGaN cladding layers, a highly efficient UV LED at 340nm was achieved with 1mW output under 800mA/mm2 DC drive current.