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841.
This paper identifies a number of significant gaps between the principles of good practice in research with children and the practical realities of conducting a research project with children. The context of the discussion is an ongoing research study of children and young people in Scotland with a parent or carer with HIV. The paper argues that conducting research with what is a hidden (and in many ways secret) population throws into sharp relief some difficulties and contradictions that are at the heart of the research process. The paper does not intend to present easy answers to the complex questions that it raises: the research project it describes is ongoing and not yet at the stage of disseminating findings in any definitive way. Moreover, it seems likely that there are no answers to the questions raised, but that the act of posing the questions may contribute to the development of better, more reflexive research with children.  相似文献   
842.
Researchers often use social indicators in their analysis of community problems and the subsequent proposals. However these researchers rarely consider the constraints placed on these indicators by construction and measurement problems. Some of these indicators are reviewed with particular reference to conceptualization of social phenomena and the intrusion of values. In the latter regard comment is made on the use of social indicators by political decision makers and policy planners.  相似文献   
843.
The properties of a method of estimating the ratio of parameters for ordered categorical response regression models are discussed. If the link function relating the response variable to the linear combination of covariates is unknown then it is only possible to estimate the ratio of regression parameters. This ratio of parameters has a substitutability or relative importance interpretation.

The maximum likelihood estimate of the ratio of parameters, assuming a logistic function (McCullagh, 1980), is found to have very small bias for a wide variety of true link functions. Further it is shown using Monte Carlo simulations that this maximum likelihood estimate, has good coverage properties, even if the link function is incorrectly specified. It is demonstrated that combining adjacent categories to make the response binary can result in an analysis which is appreciably less efficient. The size of the efficiency loss on, among other factors, the marginal distribution in the ordered categories  相似文献   
844.
Summary. A Bayesian method for segmenting weed and crop textures is described and implemented. The work forms part of a project to identify weeds and crops in images so that selective crop spraying can be carried out. An image is subdivided into blocks and each block is modelled as a single texture. The number of different textures in the image is assumed unknown. A hierarchical Bayesian procedure is used where the texture labels have a Potts model (colour Ising Markov random field) prior and the pixels within a block are distributed according to a Gaussian Markov random field, with the parameters dependent on the type of texture. We simulate from the posterior distribution by using a reversible jump Metropolis–Hastings algorithm, where the number of different texture components is allowed to vary. The methodology is applied to a simulated image and then we carry out texture segmentation on the weed and crop images that motivated the work.  相似文献   
845.
Traditionally decision sciences has been plagued with the problem of implementation, i.e., transforming a sound theoretical technique into an operational system. Most researchers who study the problem concentrate on identifying factors which relate to implementation or on identifying the change process required to achieve implementation. In a recent study, Sorensen and Zand [24] demonstrate that the Lewin-Schein change theory explains the process necessary for achieving implementation. While the Lewin-Schein theory explains the required change process, the theory does not address the question of how one brings about change. The purpose of this article is to describe a “gaming” approach for accomplishing change. A case example is given to demonstrate the proposed implementation methodology.  相似文献   
846.
The distinction between ill-structured and well-structured decision problems is extended in this paper to include the degree of familiarity that a decision maker has with the initial state of the problem, its desired state, and appropriate transformations for resolving the problem. It is shown that problem ill-structuredness may result from inadequate information regarding any of these components and that the nature of problem ill-structuredness has important implications for problem formulation and solution. A decision tree is presented which represents strategies for either reformulating primary problems of each class of ill-structuredness to a more readily solved form, or solving the problem as initially formulated.  相似文献   
847.
A paucity of research has examined the individual and cumulative effects of conventional and expanded adverse childhood experiences (ACEs) on maternal functioning, especially among low-income Black mothers. Using self-report data from a subsample of Black mothers (N = 157) who participated in a larger study to evaluate the effectiveness of an urban public prekindergarten program in the mid-Atlantic region of the United States, we examined the prevalence of ACEs and the individual and cumulative effects of conventional (i.e., family trauma and dysfunction) and expanded (i.e., community stressors) ACEs on depression and health among low-income Black mothers. Findings indicated that Black mothers had more exposure to expanded than conventional ACEs. Hierarchical regression analyses revealed that experience of physical neglect was significantly associated with depression and physical abuse with compromised health, and perceived experience of racism was a predictor of depression and compromised health. More conventional and expanded ACEs were associated with clinical levels of depression and compromised health. Findings highlight the need for more research related to the impact of ACEs, especially expanded ACEs, on mental and behavioural health outcomes. Additionally, our findings indicate the need for more trauma-informed care to reduce and address the impact of individual and community-level adversities on low-income Black mothers.  相似文献   
848.
Repeated reporting to child protection is common. One approach to early intervention is for jurisdictions to receive and respond to child protection concerns raised before children are born. Despite this, little research has comprehensively examined subsequent child protection contact for those first reported prenatally. This study aimed to examine the subsequent child protection contact for up to a two-year period for a cohort of children who were reported about prebirth. Child protection administrative data were extracted for 640 children reported for a concern about an unborn child in a single jurisdiction during 2014. Data about child protection contacts included reports, investigations, substantiations and out-of-home placements for children reported prenatally. Of the 640 children, 79% reported about prenatally also had contact with child protection between birth and age two. From birth and up to age two, children reported prenatally had between zero and 21 reports. Twenty-two per cent of the children reported prenatally were removed from their birth parents and placed in out-of-home care prior to age two. These findings highlight the importance of intervening and supporting families prior to and during pregnancy to reduce harm to children and reduce the need for contact with child protection.  相似文献   
849.
The U.S. Environmental Protection Agency's (EPA) Integrated Risk Information System (IRIS) database, the authoritative source of U.S. risk assessment toxicity factors, currently lacks an oral reference dose (RfD) for copper. In the absence of such a value, various health-based reference values for copper are available for use in risk assessment. We summarize the scientific bases and differences in assumptions among key reference values for ingested copper to guide selection of appropriate values for risk assessment. A comprehensive review of the scientific literature best supports the oral RfD of 0.04 mg/kg body weight/day derived by EPA from their Drinking Water Action Level. This value is based on acute gastrointestinal effects but is further supported by broader analysis of copper deficiency and toxicity.  相似文献   
850.
Mothers who are at risk of losing custody of their children represent a vulnerable population whose voices are seldom heard. Exploring their perspectives of parenting, their child and the relationship with their child—their ‘parenting representations’—can improve our understanding of their struggles and inform interventions. Research in this area so far has been predominantly quantitative, meaning valuable information about subjective experiences is often lost. The present study sought to address this gap by thematically analysing interviews with eight mothers with under-3-year-olds on the edge of Local Authority care, completed at the beginning of a therapeutic intervention. Results are reported around five themes: ‘Idealistic portrayal of the child and the relationship’, ‘Struggling as a parent’, ‘Shadows of the past’, ‘The child and motherhood as comfort’ and ‘Anxiety about loss and fighting for the child’. The parenting struggles of mothers in this population are complex and multi-faceted, fuelled by unresolved relational trauma, fears of further pain, adversity and difficulties in accessing and trusting support. Successful interventions are likely to require comprehensive, long-term approaches that holistically address mothers' unmet physical and emotional needs and begin with building relational trust.  相似文献   
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