19 research outputs found
The Puzzle of the Flyby Anomaly
Close planetary flybys are frequently employed as a technique to place
spacecraft on extreme solar system trajectories that would otherwise require
much larger booster vehicles or may not even be feasible when relying solely on
chemical propulsion. The theoretical description of the flybys, referred to as
gravity assists, is well established. However, there seems to be a lack of
understanding of the physical processes occurring during these dynamical
events. Radio-metric tracking data received from a number of spacecraft that
experienced an Earth gravity assist indicate the presence of an unexpected
energy change that happened during the flyby and cannot be explained by the
standard methods of modern astrodynamics. This puzzling behavior of several
spacecraft has become known as the flyby anomaly. We present the summary of the
recent anomalous observations and discuss possible ways to resolve this puzzle.Comment: 6 pages, 1 figure. Accepted for publication by Space Science Review
Perceptions of 'coming out' among British Muslim gay men
The cultural processes of heteronormativity and compulsory heterosexuality are acutely active within Islamic societies. The present study explored perceptions of 'coming out' among a group of British Muslim gay men (BMGM), focussing upon the potential consequences for identity processes and psychological well-being. Ten BMGM of Pakistani descent were interviewed using a semi-structured interview schedule. Interview transcripts were subjected to interpretative phenomenological analysis and informed by identity process theory. Four superordinate themes are reported, including (1) 'social representational constraints upon "coming out"'; (2) ' "coming out": a source of shame and a threat to distinctiveness'; (3) 'fear of physical violence from ingroup members'; and (4) 'foreseeing the future: "coming out" as a coping strategy'. Data suggest that BMGM face a bi-dimensional homophobia from ethno-religious ingroup members and the general population, which can render the prospect of 'coming out' threatening for identity. Theoretical and practical implications of this research are discussed
Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.
BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362
Treating first episode psychosis - The service users' perspective:A focus group evaluation
UK national guidance has prioritized developing specialist services for first episode psychosis. Such services are in the early stages of development and a definitive treatment model has yet to be established. The aim of this study was to explore service users' experiences of a first episode intervention designed along evidence-based 'best practice' guidelines and to establish specific elements seen as effective to help inform future service planning and provision. Twelve users of a specialist first episode service participated in focus groups. These were then analyzed using Interpretative Phenomenological Analysis, a specialized form of content analysis. Key elements identified by the service users included the 'human' approach as a key to the recovery process, being involved in treatment decisions, flexibility of appointments, high nurse to patient ratio, reduction in psychotic symptoms, increased confidence and independence and the provision of daily structure. To our knowledge, this is the first systematic qualitative evaluation of users' experience of a specialist first episode treatment intervention. Our findings indicate that adherence to best practice guidelines was appreciated. Regular focus groups provide a continuous audit cycle incorporating service improvements in line with government recommendations, centrally informed by the service users' and caregivers' perspective
Treating first episode psychosis - the service users' perspective: a focus group evaluation
A identidade capixaba em questão: uma análise psicossocial The capixaba's identity in question: a psychosocial study
Buscou-se o desenvolvimento de um estudo abarcando as representações sociais de professores sobre o folclore, verificando-se as conexões destas com a construção da identidade social. A pesquisa abarcou 32 docentes do ensino fundamental da rede pública municipal de Vitória. A coleta de dados realizou-se por meio de um questionário semi-estruturado que versou sobre temas relativos à problemática folclore capixaba e identidade. As questões estruturadas tiveram suas respostas tabuladas com o intuito de fornecerem dados quantitativos, já as respostas livres foram organizadas tendo em vista a construção de um corpus representacional que permitisse a aplicação de uma análise temática de conteúdo. Os resultados indicaram que os sujeitos associam o folclore à cultura espontânea e o caracterizam como o principal indicador de uma identidade social local (capixaba), que se constrói por meio da comunicação social, cotidianamente e constitui-se das tradições culturais em geral, tanto materiais quanto imateriais.<br>Searched the development of a study on the social representations of teachers about the folklore, verifying the connections of these with the construction of the social identity. The research comprise 32 teachers of the basic education of the public municipal net of Vitória The collection of data was carried through by a half-structuralized questionnaire that turned on the problematic of folklore and identity. The structuralized questions had its answers tabulated with intention to supply quantitative information, already the free answers had been organized in view of the construction of a corpus that allowed the application of a thematic analysis of content. The results had indicated that teachers associate the folklore to the spontaneous culture and they characterize it as the main pointer of a local social identity (capixaba), that is constructed by means of the social communication, daily, and consists of the cultural traditions in general, material as much as immaterial
Combined design of structures and controllers for optimal maneuverability
This paper treats the problem of the combined design of structure/control systems for achieving optimal maneuverability. A maneuverability index which directly reflects the time required to perform a given maneuver or set of maneuvers is introduced. By designing the flexible appendages of a spacecraft, its maneuverability is optimized under the constraints of structural properties, and of the postmaneuver spill-over being within a specified bound. The spillover reduction is achieved by making use of an appropriate control design model. The distributed parameter design problem is approached using assumed shape functions and finite element analysis with dynamic reduction. Characteristics of the problem and problem solving procedures have been investigated. Adaptive approximate design methods have been developed to overcome computational difficulties. It is shown that the global optimal design may be obtained by tuning the natural frequencies of the spacecraft to satisfy specific constraints. We quantify the difference between a lower bound to the objective function associated with the original problem and the estimate obtained from the modified problem as the index for the adaptive refinement procedure. Numerical examples show that the results of the optimal design can provide substantial improvement.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46088/1/158_2005_Article_BF01744056.pd