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Results from pointed ROSAT PSPC observations of nine single WN-type Wolf-Rayet stars are presented. Spectra of sufficient quality were obtained for two of them (WR1, WR110). The long exposure (35.5 ksec) X-ray spectrum of WR1 is more closely investigated with a semi-empirical model developed by Baum et al. (1992).
N66 (WS 35, SMP 83) is a Type I (He-N rich) PN in the LMC with a high ionization degree. It shows a bipolar morphology with a filamentary structure (Dopita et al. 1993). Its central star has shown very impressive changes, in short time scale, that have been investigated. Here we describe the history of these changes:
The purpose of this study was to describe disaster preparedness strategies and behaviors among rural families who have children with special health care needs and to examine the effect of self-efficacy and response-efficacy on disaster preparedness.
Data for this study were drawn from the baseline surveys of 287 rural families with children with special health care needs who were part of a randomized controlled trial examining the impact of an intervention on disaster preparedness. Distributions of child, parent, and family characteristics were examined by preparedness. Linear regression models were built to examine the impact of self-efficacy and response-efficacy on level of disaster preparedness.
Disaster preparedness (overall, emergency plan, discussion/practice, and supplies) was low (40.9-69.7%) among study families. Disaster preparedness was found to increase with each unit increase in the level of self-efficacy and family resilience sources across all 4 categories of preparedness.
Disaster preparedness among rural families with children with special health care needs is low, which is concerning because these children may have increased vulnerability to adverse outcomes compared to the general population. Results suggest that increasing the levels of self-efficacy and family resilience sources may increase disaster preparedness. (Disaster Med Public Health Preparedness. 2016;10:225–232)
Migratory fishes are natural wonders. For many people, the term migratory fish evokes images of salmon audaciously jumping at waterfalls as they return to their own riverine birthplace to spawn after years of growth in the ocean, but freshwater fishes actually show a broad spectrum of migration strategies. Migratory fishes include small species – three-spined sticklebacks that spawn in coastal streams around the northern Pacific and gobies that move from the ocean into tropical island streams by climbing waterfalls (McDowall, 1988) – as well as some of the largest freshwater fishes in the world, such as the Mekong dog-eating catfish and the Chinese paddlefish (Stone, 2007). Aside from migratory habits, these species have few shared characteristics; they encompass numerous evolutionary lineages, enormous differences in life history, and every possible direction and distance of migration. Biologists treat migratory freshwater fishes as a functional group because their life-history strategy revolves around long-distance movement between ecosystems in a perilous quest to take advantage of both high-quality breeding sites and bountiful feeding areas. As humans have physically blocked fish migrations, degraded breeding and feeding grounds and relentlessly harvested migrants for their flesh and roe, many populations have declined or been extirpated. This chapter will provide an overview of fundamental and applied research that is helping to guide efforts to conserve migratory freshwater fishes.
For practical purposes, we define migratory behaviour as the synchronized movement of a substantial proportion of a population between distinct habitats, which is repeated through time within or across generations. Modern definitions of fish migrations typically recognise both the adaptive benefits of migrating and individual variation in executing the general strategy (see McDowall, 1988; Lucas & Baras, 2001). Not every individual must move, the timing may vary somewhat from year to year, and the motive for migrating may include seeking refuge from harsh conditions in addition to breeding and feeding. Nonetheless, in most cases, migration is critical to individual fitness and population persistence because it enables specialised use of different habitats for growth and reproduction. Where their migration routes are blocked or key habitats are lost, migratory fishes often suffer rapid and catastrophic losses.
Human appropriation and degradation of the Earth's freshwater ecosystems (Vörösmarty et al., 2010; Carpenter et al., 2011) have transformed this reliance on multiple habitats into a detriment for many migratory fishes.
Phonological alternations in homorganic nasal–stop sequences provide a continuing topic of investigation for phonologists and phoneticians alike. Surveys like Herbert (1986), Rosenthal (1989), Steriade (1993) and Hyman (2001) demonstrate that cross-linguistically the most common process is for the postnasal stop to become voiced, as captured by Pater’s (1999) markedness constraint *NT. However, as observed since Hyman (2001), *NT alone does not account for all postnasal patterns of laryngeal alternation. In this paper, we focus on three problematic patterns. First, in some languages with a two-way laryngeal contrast, voiceless stops are aspirated postnasally, i.e. the contrast between NT and ND is enhanced, not neutralized. Second, in some languages with a three-way laryngeal contrast, the voicing contrast is maintained postnasally, while the aspiration contrast neutralizes in favour of aspiration. Third, in other languages with a three-way laryngeal contrast we find the opposite postnasal aspiration neutralization: aspiration is lost. We argue that an analysis based on perceptual cues provides the best account for this range of alternations. It demonstrates the crucial role of perceptual cues and laryngeal contrasts in a particular language while fitting the range of patterns into an Optimality Theoretic factorial typology that covers a wider range of postnasal laryngeal alternations than previous analyses.
The B fields in OB stars (BOB) survey is an ESO large programme collecting spectropolarimetric observations for a large number of early-type stars in order to study the occurrence rate, properties, and ultimately the origin of magnetic fields in massive stars. As of July 2014, a total of 98 objects were observed over 20 nights with FORS2 and HARPSpol. Our preliminary results indicate that the fraction of magnetic OB stars with an organised, detectable field is low. This conclusion, now independently reached by two different surveys, has profound implications for any theoretical model attempting to explain the field formation in these objects. We discuss in this contribution some important issues addressed by our observations (e.g., the lower bound of the field strength) and the discovery of some remarkable objects.
To study whether employees who disclose a psychiatric diagnosis, such as depression risk stigmatisation and discrimination at the workplace.
Randomised experimental study with 748 managers from German companies incorporating four case vignettes displaying an employee with different ‘diagnoses’ (depression, burnout, private crisis and thyroid dysfunction), but identical unspecific complaints. Main outcome measures were the managers' attitudes and their impact on stigmatisation with respect to job performance.
In nearly all aspects of job performance, the diagnosis depression (psychiatric disorder) was seen as more critical than the diagnosis of a thyroid dysfunction (somatic disease). The diagnosis ‘burnout’ did not prove to be less stigmatising than ‘depression’. Likewise ‘private crisis’ was rated less favourably than thyroid dysfunction.
Therefore, employees have to evaluate if they disclose their psychiatric disorder or if they conceal it as a somatic illness.
The development of infrared observational facilities has revealed a number of massive stars in obscured environments throughout the Milky Way and beyond. The determination of their stellar and wind properties from infrared diagnostics is thus required to take full advantage of the wealth of observations available in the near and mid infrared. However, the task is challenging. This session addressed some of the problems encountered and showed the limitations and successes of infrared studies of massive stars.
Recent studies have claimed the existence of very massive stars (VMS) up to 300 M⊙ in the local Universe. As this finding may represent a paradigm shift for the canonical stellar upper-mass limit of 150 M⊙, it is timely to discuss the status of the data, as well as the far-reaching implications of such objects. We held a Joint Discussion at the General Assembly in Beijing to discuss (i) the determination of the current masses of the most massive stars, (ii) the formation of VMS, (iii) their mass loss, and (iv) their evolution and final fate. The prime aim was to reach broad consensus between observers and theorists on how to identify and quantify the dominant physical processes.
Diagnostic errors can have tremendous consequences because they can result in a fatal chain of wrong decisions. Experts assume that physicians' desire to confirm a preliminary diagnosis while failing to seek contradictory evidence is an important reason for wrong diagnoses. This tendency is called ‘confirmation bias’.
To study whether psychiatrists and medical students are prone to confirmation bias and whether confirmation bias leads to poor diagnostic accuracy in psychiatry, we presented an experimental decision task to 75 psychiatrists and 75 medical students.
A total of 13% of psychiatrists and 25% of students showed confirmation bias when searching for new information after having made a preliminary diagnosis. Participants conducting a confirmatory information search were significantly less likely to make the correct diagnosis compared to participants searching in a disconfirmatory or balanced way [multiple logistic regression: odds ratio (OR) 7.3, 95% confidence interval (CI) 2.53–21.22, p<0.001; OR 3.2, 95% CI 1.23–8.56, p=0.02]. Psychiatrists conducting a confirmatory search made a wrong diagnosis in 70% of the cases compared to 27% or 47% for a disconfirmatory or balanced information search (students: 63, 26 and 27%). Participants choosing the wrong diagnosis also prescribed different treatment options compared with participants choosing the correct diagnosis.
Confirmatory information search harbors the risk of wrong diagnostic decisions. Psychiatrists should be aware of confirmation bias and instructed in techniques to reduce bias.
The photoluminescence (PL) infrared (IR)-band of p-doped porous Si (PS) films is studied by steady-state and time-resolved PL and by photoluminescence excitation (PLE) in detail. In analogy to the S-band in the visible the IR-band shifts to higher energies with reduced average nanocrystal size. The IR- and S-bands are very different in their decay behavior and in their recombination lifetimes. The temperature-dependent PL intensity shows non-exponential decay with lifetime distributions in the nsec-µsec range in contrast to the stretched exponential decay shape of the S-band corresponding to lifetime distributions in the μsec -msec range. The origin of the IR-band is likely related to radiative recombination at deep defects in Si nanocrystals with quantum-upshifted band gaps.
During the growth of the first monolayer, Cu has been shown to form in 2d islands pseudomorphic to the Ru 0001) surface under a tensile strain of -6%. The chemical behavior of such films has been found to be unlike that of either of the pure elements both from the standpoint of catalytic activity and molecular adsorption properties. In addition, these strainedlayer films have unique electronic properties. Specifically, we have identified a set of interface and surface states near the K point in the surface Brillioun zone. Here are shown new results concerning the behavior of the interface states with respect to CO adsorption. Specifically, CO is found to attenuate all Cu/Ru ARUPS structures except those due to the antibonding components of the interface states and these components move to higher binding energy with CO coverage. An analysis of these results, based on the properties of the interface states, indicates that there is negligible direct interaction between the CO orbitals and the metal d states. The increased bonding that is seen for CO on Cu/Ru compared to CO on Cu is suggested to result from an enchanced polarizability of the Cu 4s states due to the proximity of the Ru substate.
We develop two and three-body classical interatomic potentials that model structural energies for silicon. These potentials provide a global fit to a database of firstprinciples calculations of the energy for bulk and surface silicon structures which spans a wide range of atomic coordinations and bonding geometries. This is accomplished using a new “separable” form for the 3-body potential that reduces the 3-body energy to a product of 2-body sums and leads to computations of the energy and atomic forces in n2 steps as opposed to n3 for a general 3-body potential. Simulated annealing is performed to find globally minimum energy states of Si-atom clusters with these potentials using a Langevin molecular dynamics approach.
The annealing response of amorphous Al based alloy samples were investigated to assess the role of the as-quenched state on primary crystallization of Al nanocrystals(nc). Continuous heating differential scanning calorimetry (DSC) traces of amorphous Al87Ni10Ce3 powders were compared to those from melt spun ribbon (MSR) to examine the effect of sample subdivision on primary crystallization. While the powders exhibited the same onset temperature as MSR, thermal cycling experiments show fine powder sizes reacting at the onset temperature and coarse powder sizes with the lowest melt quench rate transforming at the highest primary reaction temperature. In Al92Sm8 MSR, a kinetics analysis of Al nc distributions indicates a notable effect of the as-quenched state on primary crystallization during isothermal annealing. With Al88Y7Fe5 MSR intense deformation can induce thedevelopment of an Al nc distribution without thermal annealing. In each case examined, the results support the inclusion of quenched in clusters in the analysis of primary crystallization reactions.
Several proposals involving solute effects, phase separation or quenched-in nuclei and heterogeneous nucleation have been advanced to account for the high nanocrystal density that evolves during primary crystallization in marginal glass-forming alloys, but recent crystallization measurements and kinetics analyses provide new evidence for the role of the as-quenched structure on nanocrystal synthesis. Here, isothermal microcalorimetry investigations and quantitative electron microscopy measurements including high-resolution imaging and electron spectroscopy analyses were performed on a model system at different temperatures well below the glass transition to monitor the nanocrystallization isothermally as a function of time. From the combined measurements, the size distribution and the transformed fraction can be determined with a high accuracy for extended ranges of temperatures and times. In addition, calorimetric measurements in the glassy, liquid and crystalline states of the model alloy serves to analyze, for the first time, the fragility characteristics of a marginal glass-former that presents an important parameter in the context of the kinetic stability of the material against premature crystallization.
We have used fluctuation electron microscopy (FEM) to measure nanoscale mediumrange order in amorphous Al92Sm8. Samples of this amorphous alloy formed by rapid quenching (melt-spinning) show a high density of pure Al nanocrystals (>1020 m-3) after low temperature (< 250 °C) devitrification. In samples amorphized by deformation (cold-rolling), primary Al-crystallization does not occur. This difference in devitrification behavior suggests an underlying structural difference in the amorphous state. FEM is a quantitative microscopy technique for determining nanoscale medium-range order in amorphous materials. Our measurements show that amorphous alloys formed by melt-spinning and cold-rolling have significant structural differences, and that annealing melt-spun alloy under conditions previously shown to modify the devitrification thermodynamics also changes the medium-range structure.
Background and objective: Spinal cord stimulation has been used successfully for many years in the management of neuropathic pain. Nociceptive pathways are closely integrated into many autonomic reflexes. The aim was to test the hypothesis that pain relief caused by spinal cord stimulation is related to changes in peripheral skin blood flow.
Methods: Twelve patients with spinal cord stimulators implanted as a treatment for neuropathic pain were entered into the study. Laser Doppler perfusion scanning was used as a direct method for selective measurement of changes in skin (peripheral) blood flow. Measurements were taken before and after the onset of spinal cord stimulation over the site of its sensory projection. The degree of pain relief due to spinal cord stimulation and the skin temperature of each patient were also recorded.
Results: Apart from one patient, spinal cord stimulation did not change skin blood flow in a statistically significant manner.
Conclusions: Pain relief due to spinal cord stimulation is not related to changes of skin blood flow.