4,160 research outputs found
A VLA Survey For Faint Compact Radio Sources in the Orion Nebula Cluster
We present Karl G. Janksy Very Large Array (VLA) 1.3 cm, 3.6 cm, and 6 cm
continuum maps of compact radio sources in the Orion Nebular Cluster. We
mosaicked 34 square arcminutes at 1.3 cm, 70 square arcminutes at 3.6 cm and
109 square arcminutes at 6 cm, containing 778 near-infrared detected YSOs and
190 HST-identified proplyds (with significant overlap between those
characterizations). We detected radio emission from 175 compact radio sources
in the ONC, including 26 sources that were detected for the first time at these
wavelengths. For each detected source we fit a simple free-free and dust
emission model to characterize the radio emission. We extrapolate the free-free
emission spectrum model for each source to ALMA bands to illustrate how these
measurements could be used to correctly measure protoplanetary disk dust masses
from sub-millimeter flux measurements. Finally, we compare the fluxes measured
in this survey with previously measured fluxes for our targets, as well as four
separate epochs of 1.3 cm data, to search for and quantify variability of our
sources.Comment: 13 pages, 6 figures, 4 tables, ApJ, in pres
Movement side effects of antipsychotic drugs in adults with and without intellectual disability: UK population-based cohort study
OBJECTIVES: To measure the incidence of movement side effects of antipsychotic drugs in adults with intellectual disability and compare rates with adults without intellectual disability. DESIGN: Cohort study using data from The Health Improvement Network. SETTING: UK primary care. PARTICIPANTS: Adults with intellectual disability prescribed antipsychotic drugs matched to a control group of adults without intellectual disability prescribed antipsychotic drugs. OUTCOME MEASURES: New records of movement side effect including acute dystonias, akathisia, parkinsonism, tardive dyskinaesia and neuroleptic malignant syndrome. RESULTS: 9013 adults with intellectual disability and a control cohort of 34 242 adults without intellectual disability together contributed 148 709 person-years data. The overall incidence of recorded movement side effects was 275 per 10 000 person-years (95% CI 256 to 296) in the intellectual disability group and 248 per 10 000 person-years (95% CI 237 to 260) in the control group. The incidence of any recorded movement side effect was significantly greater in people with intellectual disability compared with those without (incidence rate ratio 1.30, 95% CI 1.18 to 1.42, p<0.001, after adjustment for potential confounders), with parkinsonism and akathisia showing the greatest difference between the groups. Neuroleptic malignant syndrome, although occurring infrequently, was three times more common in people with intellectual disability-prescribed antipsychotic drugs (incidence rate ratio 3.03, 95% CI 1.26 to 7.30, p=0.013). Differences in rates of movement side effects between the groups were not due to differences in the proportions prescribed first and second-generation antipsychotic drugs. CONCLUSIONS: This study provides evidence to substantiate the long-held assumption that people with intellectual disability are more susceptible to movement side effects of antipsychotic drugs. Assessment for movement side effects should be integral to antipsychotic drug monitoring in people with intellectual disability. Regular medication review is essential to ensure optimal prescribing in this group
Mental illness, challenging behaviour, and psychotropic drug prescribing in people with intellectual disability: UK population based cohort study
To describe the incidence of recorded mental illness and challenging behaviour in people with intellectual disability in UK primary care and to explore the prescription of psychotropic drugs in this group
UK psychiatrists' experience of withdrawal of antipsychotics prescribed for challenging behaviours in adults with intellectual disabilities and/or autism.
BACKGROUND: A high proportion of adults with intellectual disabilities are prescribed off-licence antipsychotics in the absence of a psychiatric illness. The National Health Service in England launched an initiative in 2016, 'Stopping over-medication of people with a learning disability [intellectual disability], autism or both' (STOMP), to address this major public health concern. AIMS: To gain understanding from UK psychiatrists working with adults with intellectual disabilities on the successes and challenges of withdrawing antipsychotics for challenging behaviours. METHOD: An online questionnaire was sent to all UK psychiatrists working in the field of intellectual disability (estimated 225). RESULTS: Half of the 88 respondents stated that they started withdrawing antipsychotics over 5 years ago and 52.3% stated that they are less likely to initiate an antipsychotic since the launch of STOMP. However, since then, 46.6% are prescribing other classes of psychotropic medication instead of antipsychotics for challenging behaviours, most frequently the antidepressants. Complete antipsychotic discontinuation in over 50% of patients treated with antipsychotics was achieved by only 4.5% of respondents (n = 4); 11.4% reported deterioration in challenging behaviours in over 50% of patients on withdrawal and the same proportion (11.4%) reported no deterioration. Only 32% of respondents made the diagnosis of psychiatric illness in all their patients themselves. Family and paid carers' concern, lack of multi-agency and multidisciplinary input and unavailability of non-medical psychosocial intervention are key reported factors hampering the withdrawal attempt. CONCLUSIONS: There is an urgent need to develop national guidelines to provide a framework for systematic psychotropic drug reviews and withdrawal where possible
Developing biodiversity indicators for african birds
Biodiversity indicators are essential for monitoring the impacts of pressures on the state of nature, determining the effectiveness of policy responses, and tracking progress towards biodiversity targets and sustainable development goals. Indicators based on trends in the abundance of birds are widely used for these purposes in Europe and have been identified as priorities for development elsewhere. To facilitate this we established bird population monitoring schemes in three African countries, based on citizen science approaches used in Europe, aiming to monitor population trends in common and widespread species. We recorded > 500 bird species from c. 450 2-km transects in Botswana, > 750 species from c. 120 transects in Uganda, and > 630 species from c. 90 transects in Kenya. Provisional Wild Bird Indices indicate a strong increase in bird populations in Botswana and a small decrease in Uganda. We also provide comparisons between trends of habitat generalists and specialists, of birds within and outside protected areas, and between Afro-Palearctic migrants and resident birds. Challenges encountered included recruiting, training and retaining volunteer surveyors, and securing long-term funding. However, we show that with technical support and modest investment (c. USD 30,000 per scheme per year), meaningful biodiversity indicators can be generated and used in African countries. Sustained resourcing for the existing schemes, and replication elsewhere, would be a cost-effective way to improve our understanding of biodiversity trends globally, and measure progress towards environmental goals
Experiment and numerical modelling of a demountable steel connection system for reuse
Currently, steel reuse is only a marginal practice. To facilitate deconstruction and efficient reuse of steel components, an innovative connection system was proposed. This system adopts a ‘Block Shear Connector (BSC)’ that allows beam length to be standardised and suitable for a wide range of different sizes of the supporting members within the same planning grid. This paper presents the experimental and numerical studies of a beam-to-beam connection using BSCs. The BSC used was made from a standard universal HE / UC section and was bolted to the beams by using partial depth end plates. The experimental results provided the shear resistance, moment-rotation, failure behaviour, demountability and reusability of the steel components. Further numerical simulation conducted investigated the effect of some key parameters (steel strength, thickness of BSC web, thickness of BSC flange, initial bolt stress) on the behaviour of the connections. The results obtained highlighted the demountability of this innovative bolted connection system and the reusability of structural components
Effect of dowel shear connector on performance of slim-floor composite shear beams
© 2020 This paper presents the numerical modelling and analysis of slim-floor composite beam systems using different shear connector arrangements. A finite element model was developed and validated through comparing the prediction with the results obtained from the experimental study. A parametric study was conducted to examine the effect of typical parameters of shear connectors, including the diameter of the concrete dowel cylinder, incorporating dowel reinforcement and concrete strength, etc. The comparison and analysis further clarified the concrete dowel, mechanism and development of shear resistance and overall load-bearing capacity. The findings based on the numerical simulation provide a deeper insight into the behaviour of this type of slim-floor composite beam system. Through both experimental and numerical studies, the structural merits of this composite beam system were highlighted
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Numerical study of steel-concrete composite cellular beam using demountable shear connectors
Steel concrete composite beams have been increasingly used in practice due to their advantages with respect to their structural features and constructability. However, in conventional composite beam systems composite action is applied via shear connectors welded at the top flange of the down-stand steel beam and embedded in the concrete slabs, making it less favourable for the beam system to be disassembled and reused. This paper presents a numerical study of a new composite beam system consisting of a cellular steel beam, metal deck flooring and demountable shear connectors. According to the experimental study, this composite beam system made the demounting, reassembly, and member reuse possible, and did not compromise the loading capacity. In the numerical study presented in the paper, a finite element model was developed and validated against the results obtained from the previous experimental study. The parametric study further examined the effects of concrete strength, shear connector arrangements and asymmetry ratios of steel beam section to the load capacity of the composite beam system. The analysis and comparison provided a deeper insight into the behaviour of this type of shear connector. Through this numerical study, the structural merits of the composite beam system using demountable shear connectors were highlighted. Finally, the mid-span plastic moment of the composite beam was predicted using the direction method provided in SCI publications and compared with the moment–deflection relationship obtained from FE modelling
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