3,583 research outputs found
Birefringent Electroweak Textures
The behaviour of electromagnetic waves propagating through an electroweak
homilia string network is examined. This string network is topologically stable
as a cosmic texture, and is characterized by the spatial variation of the
isospin rotation of the Higgs field. As a consequence the photon field couples
to the intermediate vector bosons, producing a finite range electromagnetic
field. It is found that the propagation speed of the photon depends on its
polarization vector, whence an homilia string network acts as a birefringent
medium. We estimate the birefringent scale for this texture and show that it
depends on the frequency of the electromagnetic wave and the length scale of
the homilia string network.Comment: 10 page
A study of the effect of space radiation on silicon integrated circuits, phase 3, volume 2 Final report, 10 Apr. 1967 - 9 Apr. 1968
Characterization plans for studying effect of space radiation on silicon integrated microcircuit
Managing a sustainable, low carbon supply chain in the English National Health Service: The views of senior managers.
Objectives:In an effort to reduce costs and respond to climate change, health care providers (Trusts) in England have started to change how they purchase goods and services. Many factors, both internal and external, affect the supply chain. Our aim was to identify those factors, so as to maintain future supply and business continuity in health and social care.Methods:Qualitative interviews with 20 senior managers from private and public sector health service providers and social care providers in south west England. Interviews were recorded, transcribed and thematically analysed.Results:There were four areas of concern: contradictions with government legislation which caused confusion about how best to deliver sustainable solutions; procurement was unclear and created multiple approaches to purchasing bulk items at low cost; internal organizational systems needed to be reconsidered to embed sustainability; and embedding sustainability requires a review of organizational systems. There are examples of sustainability solutions throughout the National Health Service (NHS) but the response continues to be patchy. More research is needed into why some Trusts and some staff do not recognize the benefits of a core approach or find the systems unable to respond.Conclusions:The NHS is one of the major purchasers of goods and services in England and is therefore in an excellent position to encourage sustainable resource management, manufacturing, use and disposal
Understanding exercise behavior and drop-out through metamotivational dominance, exercise identity and motives
Despite literature exploring interventions and strategies to encourage exercise adoption and maintenance, the dropout rate of irregular exercisers, particularly within the first six months of adoption, continues to reduce the effectiveness of such interventions. Whilst a body of literature exists exploring the dropout profile of clinical patients, less is known about the psychological and theoretical differences that discriminate exercise behavior and that could be indicative of susceptibility to dropout in the general population. Our study examines whether the metamotivational constructs of reversal theory (Apter, 1989), exercise motives, and exercise identity can discriminate between males’ and females’ exercise behavior, defined in relation to length of exercise participation, consistency (frequency of previous dropout) and the main type of exercise engaged in. We created an online survey to which 973 participants responded. We used MANOVA to determine whether exercise length, consistency, or type resulted in significant differences in levels of outcome variables. Where we identified significant effects, we employed discriminant function analysis to determine whether and how the dependent variables were able to discriminate between groupings. Results indicated that differing profiles of exercise identity, metamotivational dominance, and motives for exercise could discriminate between females and males who had been exercising for different lengths of time, with different levels of exercise consistency and differing types of main exercise. Our findings indicate that specific groupings may highlight individuals who are vulnerable to dropout so that strategies can be tailored more effectively for these individuals and support more appropriate strategies to develop internalized motivation
A Test-Retest Transition Matrix: A Modification of McNemar’s Test
McNemar introduced what is known today as a test for symmetry in a two by two contingency tables. The logic of the test is based on a sample of matched pairs with a dichotomous response. In our example, the sample consists of the scores before and after an education program and the responses before and after the program. Each pair of scores is from only one person. The pretest divides the group of responders according to their answers to a dichotomous question. The posttest divides the two groups into two groups of like labels. The result is a two by two table. We construct a test of homogeneity, where the proportion of initially partitioned subjects will be equally distributed over the same partition after the program is completed, conditioned on the initial distribution
On Treating A Survey Of Convenience Sample As A Simple Random Sample
Threat of bias has kept many from using data gathered in less than optimal conditions. We maintain that when convenience sampling represents race and gender at nearly correct proportions and can be beneficial, as these two variables are quite often used as stratification variables. We compared a convenience sample with a proven sample. Race and Sex were nearly proportional as was found in the proven sample. We conclude that the convenience sample can be used as though it is simple random
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