13,663 research outputs found
Interreligious courtship and marriage in Northern Ireland
SIGLELD:D45263/83 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Automatic estimation of flux distributions of astrophysical source populations
In astrophysics a common goal is to infer the flux distribution of
populations of scientifically interesting objects such as pulsars or
supernovae. In practice, inference for the flux distribution is often conducted
using the cumulative distribution of the number of sources detected at a given
sensitivity. The resulting "-" relationship can be used to
compare and evaluate theoretical models for source populations and their
evolution. Under restrictive assumptions the relationship should be linear. In
practice, however, when simple theoretical models fail, it is common for
astrophysicists to use prespecified piecewise linear models. This paper
proposes a methodology for estimating both the number and locations of
"breakpoints" in astrophysical source populations that extends beyond existing
work in this field. An important component of the proposed methodology is a new
interwoven EM algorithm that computes parameter estimates. It is shown that in
simple settings such estimates are asymptotically consistent despite the
complex nature of the parameter space. Through simulation studies it is
demonstrated that the proposed methodology is capable of accurately detecting
structural breaks in a variety of parameter configurations. This paper
concludes with an application of our methodology to the Chandra Deep Field
North (CDFN) data set.Comment: Published in at http://dx.doi.org/10.1214/14-AOAS750 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Correlates and Consequences of Degree Purchasing among Canadian University Students
This article develops the construct of degree purchasing as an instrumental orientation towards education in which students value education primarily as a vehicle for labour market participation rather than as an avenue for learning. This study of 188 Canadian university students found that a substantial proportion of students tended to be more interested in acquiring a diploma than the learning that it represents. Female students were more instrumentally oriented than male students, and younger students devalued learning to a greater extent than older students. Finally, a degree purchasing orientation was associated with poor study habits, the use of resistance strategies in the classroom, low positive affect, and poor course performance. Implications for higher education and suggestions for future research are discussed.Cette recherche exploratoire tente d'analyser les prévalences de degree purchasing, une orientation instrumentale envers l'éducation. Les auteurs postulent que plusieurs étudiants conçoivent le diplôme universitaire comme un instrument permettant d'accéder rapidement au marché du travail sans faire les investissements requis en matière d'apprentissage. Cette recherche exploratoire réalisée auprès de 188 étudiants universitaires canadiens démontre que le degree purchasing se manifeste surtout parmi les étudiantes du sexe féminin et les étudiants moins âgés. En outre, les étudiants qui faisaient le degree purchasing avaient des mauvaises stratégies d'apprentissage ainsi qu'une faible motivation à apprendre
Young women's accounts of factors influencing their use and non-use of emergency contraception: in-depth interview study.
OBJECTIVES: To explore young women's accounts of their use and non-use of emergency contraception. DESIGN: Qualitative study using in-depth interviews. PARTICIPANTS: 30 women aged 16-25; participants from socially deprived inner city areas were specifically included. SETTING: Community, service, and educational settings in England. RESULTS: Young women's accounts of their non-use of emergency contraception principally concerned evaluations of the risk conferred by different contraceptive behaviours, their evaluations of themselves in needing emergency contraception, and personal difficulties in asking for emergency contraception. CONCLUSIONS: The attitudes and concerns of young women, especially those from disadvantaged backgrounds, may make them less able or willing than others to take advantage of recent increases in access to emergency contraception. Interventions that aim to increase the use of emergency contraception need to address the factors that influence young women's non-use of emergency contraception
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