236 research outputs found
Robotic Laser-Adaptive-Optics Imaging of 715 Kepler Exoplanet Candidates using Robo-AO
The Robo-AO Kepler Planetary Candidate Survey is designed to observe every
Kepler planet candidate host star with laser adaptive optics imaging to search
for blended nearby stars, which may be physically associated companions and/or
responsible for transit false positives. In this paper we present the results
from the 2012 observing season, searching for stars close to 715 representative
Kepler planet candidate hosts. We find 53 companions, 44 of which are new
discoveries. We detail the Robo-AO survey data reduction methods including a
method of using the large ensemble of target observations as mutual
point-spread-function references, along with a new automated
companion-detection algorithm designed for large adaptive optics surveys. Our
survey is sensitive to objects from 0.15" to 2.5" separation, with contrast
ratios up to delta-m~6. We measure an overall nearby-star-probability for
Kepler planet candidates of 7.4% +/- 1.0%, and calculate the effects of each
detected nearby star on the Kepler-measured planetary radius. We discuss
several KOIs of particular interest, including KOI-191 and KOI-1151, which are
both multi-planet systems with detected stellar companions whose unusual
planetary system architecture might be best explained if they are "coincident
multiple" systems, with several transiting planets shared between the two
stars. Finally, we detect 2.6-sigma evidence for <15d-period giant planets
being 2-3 times more likely be found in wide stellar binaries than smaller
close-in planets and all sizes of further-out planets.Comment: Accepted by ApJ. Minor updates & improved statistical analysis; no
changes to results. 15 pages, 13 figure
Optimizing aeration in pulp mill secondary treatment systems
"February 1997.""Submitted to 1997 Energy Manager's Workshop, Houston, Texas, April 23-24, 1997.
Comparisons of predictors for typhoid and paratyphoid fever in Kolkata, India
BACKGROUND: Exposure of the individual to contaminated food or water correlates closely with the risk for enteric fever. Since public health interventions such as water improvement or vaccination campaigns are implemented for groups of individuals we were interested whether risk factors not only for the individual but for households, neighbourhoods and larger areas can be recognised? METHODS: We conducted a large enteric fever surveillance study and analyzed factors which correlate with enteric fever on an individual level and factors associated with high and low risk areas with enteric fever incidence. Individual level data were linked to a population based geographic information systems. Individual and household level variables were fitted in Generalized Estimating Equations (GEE) with the logit link function to take into account the likelihood that household factors correlated within household members. RESULTS: Over a 12-month period 80 typhoid fever cases and 47 paratyphoid fever cases were detected among 56,946 residents in two bustees (slums) of Kolkata, India. The incidence of paratyphoid fever was lower (0.8/1000/year), and the mean age of paratyphoid patients was older (17.1 years) than for typhoid fever (incidence 1.4/1000/year, mean age 14.7 years). Residents in areas with a high risk for typhoid fever had lower literacy rates and economic status, bigger household size, and resided closer to waterbodies and study treatment centers than residents in low risk areas. CONCLUSION: There was a close correlation between the characteristics detected based on individual cases and characteristics associated with high incidence areas. Because the comparison of risk factors of populations living in high versus low risk areas is statistically very powerful this methodology holds promise to detect risk factors associated with diseases using geographic information systems
The development of a lay health worker delivered collaborative community based intervention for people with schizophrenia in India
BACKGROUND: Care for schizophrenia in low and middle income countries is predominantly facility based and led by specialists, with limited use of non-pharmacological treatments. Although community based psychosocial interventions are emphasised, there is little evidence about their acceptability and feasibility. Furthermore, the shortage of skilled manpower is a major barrier to improving access to these interventions. Our study aimed to develop a lay health worker delivered community based intervention in three sites in India. This paper describes how the intervention was developed systematically, following the MRC framework for the development of complex interventions. METHODS: We reviewed the lierature on the burden of schizophrenia and the treatment gap in low and middle income countries and the evidence for community based treatments, and identified intervention components. We then evaluated the acceptability and feasibility of this package of care through formative case studies with individuals with schizophrenia and their primary caregivers and piloted its delivery with 30 families. RESULTS: Based on the reviews, our intervention comprised five components (psycho-education; adherence management; rehabilitation; referral to community agencies; and health promotion) to be delivered by trained lay health workers supervised by specialists. The intervention underwent a number of changes as a result of formative and pilot work. While all the components were acceptable and most were feasible, experiences of stigma and discrimination were inadequately addressed; some participants feared that delivery of care at home would lead to illness disclosure; some participants and providers did not understand how the intervention related to usual care; some families were unwilling to participate; and there were delivery problems, for example, in meeting the targeted number of sessions. Participants found delivery by health workers acceptable, and expected them to have knowledge about the subject matter. Some had expectations regarding their demographic and personal characteristics, for example, preferring only females or those who are understanding/friendly. New components to address stigma were then added to the intervention, the collaborative nature of service provision was strengthened, a multi-level supervision system was developed, and delivery of components was made more flexible. Criteria were evolved for the selection and training of the health workers based on participants' expectations. CONCLUSIONS: A multi-component community based intervention, targeting multiple outcomes, and delivered by trained lay health workers, supervised by mental health specialists, is an acceptable and feasible intervention for treating schizophrenia in India
Searching for psychosis: INTREPID (1): systems for detecting untreated and first-episode cases of psychosis in diverse settings.
PURPOSE: Our understanding of psychotic disorders is largely based on studies conducted in North America, Europe and Australasia. Few methodologically robust and comparable studies have been carried out in other settings. INTREPID is a programme of research on psychoses in India, Nigeria, and Trinidad. As a platform for INTREPID, we sought to establish comprehensive systems for detecting representative samples of cases of psychosis by mapping and seeking to engage all professional and folk (traditional) providers and potential key informants in defined catchment areas. METHOD: We used a combination of official sources, local knowledge of principal investigators, and snowballing techniques. RESULTS: The structure of the mental health systems in each catchment area was similar, but the content (i.e., type, extent, and nature) differed. Tunapuna-Piarco (Trinidad), for example, has the most comprehensive and accessible professional services. By contrast, Ibadan (Nigeria) has the most extensive folk (traditional) sector. We identified and engaged in our detection system-(a) all professional mental health services in each site (in- and outpatient services-Chengalpet, 6; Ibadan, 3; Trinidad, 5); (b) a wide range of folk providers (Chengalpet, 3 major healing sites; Ibadan, 19 healers; Trinidad: 12 healers); and c) a number of key informants, depending on need (Chengalpet, 361; Ibadan, 54; Trinidad, 1). CONCLUSIONS: Marked differences in mental health systems in each catchment area illustrate the necessity of developing tailored systems for the detection of representative samples of cases with untreated and first-episode psychosis as a basis for robust, comparative epidemiological studies
Concepts of madness in diverse settings: a qualitative study from the INTREPID project.
BACKGROUND: In order to facilitate case identification of incident (untreated and recent onset) cases of psychosis and controls in three sites in India, Nigeria and Trinidad, we sought to understand how psychoses (or madness) were conceptualized locally. The evidence we gathered also contributes to a long history of research on concepts of madness in diverse settings. METHODS: We conducted focus group discussions and individual interviews to collect information about how informants in each site make sense of and respond to madness. A coding framework was developed and analyses of transcripts from the FGDs and interviews were conducted. RESULTS: Analyses suggest the following: a) disturbed behaviors are the primary sign of madness; b) madness is attributed to a wide range of causes; and, c) responses to madness are dictated by cultural and pragmatic factors. These findings are congruent with similar research that has been conducted over the past 50 years. CONCLUSIONS: The INTREPID research suggests that concepts about madness share similar features across diverse settings: a) terms for madness are often derived from a common understanding that involves disruptions in mental processes and capacities; b) madness is recognized mostly by disruptive behaviours or marked declines in functioning; c) causal attributions are varied; and, d) help-seeking is a complex process
Community Participation in Two Vaccination Trials in Slums of Kolkata, India: A Multi-level Analysis
This study aims at understanding the individual and community-level characteristics that influenced participation in two consecutive vaccine trials (typhoid and cholera) in urban slums of Kolkata, India. The study area was divided into 80 geographic clusters (communities), with 59,533 subjects aged ≥2 years for analysis. A multi-level model was employed in which the individuals were seen nested within the cluster. Rates of participation in both the trials were nearly the same; those who participated in the initial trial were likely to participate in the subsequent cholera vaccine trial. Communities with predominantly Hindu population, lower percentage of households with an educated household head, or lower percentage of households owning a motorbike had higher participation than their counterparts. At individual scale, higher participation was observed among younger subjects, females, and individuals from households with a household head who had no or minimal education. Geographic patterns were also observed in participation in the trials. The results illustrated that participation in the trial was mostly influenced by various individual and community-level factors, which need to be addressed for a successful vaccination campaign
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