2,060 research outputs found
High-performance Schottky diodes endure high temperatures
Fabrication process and aluminum/GaAs (gallium arsenide) coupling are used to produce Schottky diodes that have high cutoff frequencies and can withstand operating temperatures in excess of 500 C
Predictive validity of the HCR-20 for inpatient aggression:the effect of intellectual disability on accuracy
BackgroundPeople with intellectual disability (ID) account for a large proportion of aggressive incidents in secure and forensic psychiatric services. Although the Historical, Clinical, Risk Management 20 (HCR-20) has good predictive validity in inpatient settings, it does not perform equally in all groups and there is little evidence for its efficacy in those with ID.MethodA pseudo-prospective cohort study of the predictive efficacy of the HCR-20 for those with ID (nâ=â109) was conducted in a UK secure mental health setting using routinely collected risk data. Performance of the HCR-20 in the ID group was compared with a comparison group of adult inpatients without an ID (nâ=â504). Analysis controlled for potential covariates including security level, length of stay, gender and diagnosis.ResultsThe HCR-20 total score was a significant predictor of any aggression and of physical aggression for both groups, although the area under the curve values did not reach the threshold for a large effect size. The clinical subscale performed significantly better in those without an ID compared with those with. The ID group had a greater number of relevant historical and risk management items. The clinicians' summary judgment significantly predicted both types of aggressive outcomes in the ID group, but did not predict either in those without an ID.ConclusionsThis study demonstrates that, after controlling for a range of potential covariates, the HCR-20 is a significant predictor of inpatient aggression in people with an ID and performs as well as for a comparison group of mentally disordered individuals without ID. The potency of HCR-20 subscales and items varied between the ID and comparison groups suggesting important target areas for improved prediction and risk management interventions in those with ID
Unsung heroes: Constituency election agents in British general elections
Despite their central role in the electoral process, constituency agents have been largely overlooked by political scientists and this article seeks to rectify the omission. It sketches the origins and development of the role of agent from the late 19th century and suggests that a serious rethink of the role took place in the 1990s. Survey-based evidence about the social characteristics of agents is presented confirming that they are largely middle-aged, middle-class, well-educated men. They are also becoming more experienced, offer realistic assessments of the impact of constituency campaigning and, arguably, many take a long-term view of how their party's support can be maximised
Rhizon Sampling of Pore Waters on Scientific Drilling Expeditions: An Example from the IODP Expedition 302, Arctic Coring Expedition (ACEX)
No abstract available.
doi:10.2204/iodp.sd.4.08.2007</a
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Cross sections for the production of low energy photons by neutron interactions with fluoride and tantalum
Calcareous Nannofossils and Paleoclimatic Evolution Across the Eocene-Oligocene Transition at IODP Site U1509, Tasman Sea, Southwest Pacific Ocean
The EoceneâOligocene transition (EOT; âź34 Ma) was one of the most prominent global cooling events of the Cenozoic, coincident with the emergence of continentalâscale iceâsheets on Antarctica. Calcareous nannoplankton experienced significant assemblage turnover at a time of longâterm surface ocean cooling and trophic conditions, suggesting causeâeffect relationships between Antarctic glaciation, broader climate changes, and the response of phytoplankton communities. To better evaluate the timing and nature of these relationships, we generated calcareous nannofossil and geochemical data sets (δ18O, δ13C and %CaCO3) over a âź5 Myr stratigraphic interval recovered across the EOT from IODP Site U1509 in the Tasman Sea, South Pacific Ocean. Based on trends observed in the calcareous nannofossil assemblages, there was an overall decline of warmâoligotrophic communities, with a shift toward taxa better adapted to cooler more eutrophic conditions. Assemblage changes indicate four distinct phases caused by temperature decrease and variations in paleocurrents: late Eocene warmâoligotrophic phase, precursor diversityâdecrease phase, early Oligocene coldâeutrophic phase, and a steadyâstate cosmopolitan phase. The most prominent shift in the assemblages occurred during the âź550 kyrâlong precursor diversityâdecrease phase, which has relatively high bulk δ18O and %CaCO3 values, and predates the phase of maximum glacial expansion (Earliest Oligocene Glacial MaximumâEOGM)
Cooling Flows and Metallicity Gradients in Clusters of Galaxies
The X-ray emission by hot gas at the centers of clusters of galaxies is
commonly modeled assuming the existence of steady-state, inhomogeneous cooling
flows. We derive the metallicity profiles of the intracluster medium expected
from such models. The inflowing gas is chemically enriched by type Ia
supernovae and stellar mass loss in the outer parts of the central galaxy,
which may give rise to a substantial metallicity gradient. The amplitude of the
expected metallicity enhancement towards the cluster center is proportional to
the ratio of the central galaxy luminosity to the mass inflow rate. The
metallicity of the hotter phases is expected to be higher than that of the
colder, denser phases. The metallicity profile expected for the Centaurus
cluster is in good agreement with the metallicity gradient recently inferred
from ASCA measurements (Fukazawa et al. 1994). However, current data do not
rule out alternative models where cooling is balanced by some heat source. The
metallicity gradient does not need to be present in all clusters, depending on
the recent merging history of the gas around the central cluster galaxy, and on
the ratio of the stellar mass in the central galaxy to the gas mass in the
cooling flow.Comment: uuencoded postscript, 8 pages of text + 2 figures, accepted by The
Astrophysical Journal (Letters
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