Some decompositions of spherical distributions

Certain rotationally symmetric or spherical multivariate distributions can be factored into independent components that produce in a natural manner various uniform, chi, triangular chi, root F, triangular root F, t, disguised t, triangular root beta, Wishart and disguised Wishart distributions.     

Is bounded-vision an adequate explanation of strategic decision-making failures

One important area in which Management Science should be involved must surely be in the prevention of corporate failure. In this paper we therefore use a scientific methodology to try to identify the major causes of such failure. Two widely differing systems are examined and a large number of hypotheses considered as explanations of failure. In each case the only hypothesis which we are unable to reject, is that prior to the failure the dominant decision-makers in the system were not prepared to accept facts which were plainly available and which, if acted upon, could have prevented disaster. This allows us to suggest some ways of helping to prevent failure. Nevertheless, we feel that research into the mechanisms generating this phenomenon, which we have called bounded-vision, is required before adequate technologies can be designed.     

Area agency on aging outreach and assistance for households with older carers of an adult with a developmental disability

A demonstration project was undertaken in the state of New York to assess how area agencies on aging (AAAs) would approach outreach and direct aid to families caring for someone with a developmental disability. It was found that AAAs organized their outreach and direct-aid efforts using three main approaches: direct operation, contract operations, and multi-organizational. They generally organized staff time so that about two days per week of effort was devoted to undertaking outreach activities, conducting community education, and providing casework and referrals for target families. Four major distinctions were identified that differentiated work with older carers of persons with a developmental disability from that with other kinds of carers: complexity of problems presented by households identified, vagaries of fiscal resources, diverse household composition, and planning for eventualities. It was concluded that targeting AAAs for outreach and providing help to these carers was effective and productive and should be replicated throughout the United States.     

Social service systems for vulnerable children and families in low‐ and middle‐income countries: Establishing definitions and key components

Systems strengthening in low‐ and middle‐income countries has long been a topic of concern in global health. By comparison, until very recently, little attention has been paid to the importance of strengthening social service systems to provide a holistic perspective of children's and families' multifaceted strengths and vulnerabilities. This study has reviewed existing literature on the definitions and components of social service systems and provides an analysis of data from key informants in the field of global social welfare. Based on this information, a set of key components is presented and compared, derived from the literature and expert interviews. Existing challenges for the field include establishing consensus on terminology and critical components, implementing and documenting critical components, and linking these components to client outcomes.     

An integrated dietary assessment increases feeding event detection in an urban carnivore

Urban Ecosystems - Urbanisation radically changes habitats and alters available resources. Populations of large, highly mobile species are often extirpated at the urban-wildland interface, while...     

A Generalized Estimating Equations Approach for Analysis of the Impact of New Technology on a Trawl Fishery

The article describes a generalized estimating equations approach that was used to investigate the impact of technology on vessel performance in a trawl fishery during 1988–96, while accounting for spatial and temporal correlations in the catch-effort data. Robust estimation of parameters in the presence of several levels of clustering depended more on the choice of cluster definition than on the choice of correlation structure within the cluster. Models with smaller cluster sizes produced stable results, while models with larger cluster sizes, that may have had complex within-cluster correlation structures and that had within-cluster covariates, produced estimates sensitive to the correlation structure. The preferred model arising from this dataset assumed that catches from a vessel were correlated in the same years and the same areas, but independent in different years and areas. The model that assumed catches from a vessel were correlated in all years and areas, equivalent to a random effects term for vessel, produced spurious results. This was an unexpected finding that highlighted the need to adopt a systematic strategy for modelling. The article proposes a modelling strategy of selecting the best cluster definition first, and the working correlation structure (within clusters) second. The article discusses the selection and interpretation of the model in the light of background knowledge of the data and utility of the model, and the potential for this modelling approach to apply in similar statistical situations.     

Probabilistic Principal Component Analysis

Principal component analysis (PCA) is a ubiquitous technique for data analysis and processing, but one which is not based on a probability model. We demonstrate how the principal axes of a set of observed data vectors may be determined through maximum likelihood estimation of parameters in a latent variable model that is closely related to factor analysis. We consider the properties of the associated likelihood function, giving an EM algorithm for estimating the principal subspace iteratively, and discuss, with illustrative examples, the advantages conveyed by this probabilistic approach to PCA.     

Sense of community: Issues and considerations from a cross-cultural perspective

Behaviour settings such as work, family, church and community are primary settings in which we participate, they provide us with meaningful roles, relationships, and social identities. In fact, these are settings that provide us with a sense of community (SOC). SOC has been heralded as the guiding value for community research and action. It reflects the integration of people into networks and structures that provide feelings of belonging, identification and meaning. The concept has received much attention since the introduction of McMillan and Chavis' initial formulation. It is argued that research into SOC has been hampered by relying on the Sense of Community Index at the expense of the SOC model. Insights are drawn from cross-cultural psychology and research to highlight conceptual issues and to encourage exploration and the utilisation of alternative modes of investigation. Contex-tualist approaches including substantive theorising and narrative psychology, which have their roots in pragmatism, are promoted as frameworks for bringing community and SOC into focus as central to social and community development.