970 resultados para generic exponential family duration modeling


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For a given sheet metal forming process, an accurate determination of the contact pressure distribution experienced is an essential step towards the estimation of tool life. This investigation utilizes finite element (FE) analysis to determine the evolution and distribution of contact pressure over the die radius, throughout the duration of a channel forming process. It was found that a typical two-peak steady-state contact pressure response exists for the majority of the process. However, this was preceded by a transient  response, which produced extremely large and localized contact pressures. Notably, it was found that the peak transient contact pressure was more than double the steady-state peak. These contact pressure results may have a significant influence on the tool wear response and therefore impact current wear testing and prediction techniques. Hence, an investigation into the validity of the predicted contact pressure was conducted.

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The topic of systems of systems has been one of the most challenging areas in science and engineering due to its multidisciplinary scope and inherent complexity. Despite all attempts carried out so far in both academia and industry, real world applications are far remote. The purpose of this paper is to modify and adopt a recently developed modeling paradigm for system of systems and then employ it to model a generic baggage handling system of an airport complex. In a top-down design approach, we start modeling process by definition of some modeling goals that guide us in selection of some high level attributes. Then functional attributes are defined which act as ties between high level attributes (the first level of abstraction) and low level metrics/measurements. Since the most challenging issues in developing models for system of systems are identification and representation of dependencies amongst constituent entities, a machine learning technique is adopted for addressing these issues.

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This study documented the parenting styles among African migrants now living in Melbourne, Victoria, Australia, and assessed how intergenerational issues related to parenting in a new culture impact on family functioning and the modification of lifestyles. A total of 10 focus group discussions (five with parents and five with 13–17-year-old children; N = 85 participants) of 1.5–2 hours duration were conducted with Sudanese, Somali and Ethiopian migrant families. The analysis identified three discrete themes: (i) parenting-related issues; (ii) family functioning and family relations; and (iii) lifestyle changes and health. African migrant parents were restrictive in their parenting; controlled children's behaviours and social development through strict boundary-setting and close monitoring of interests, activities, and friends; and adopted a hierarchical approach to decision-making while discouraging autonomy among their offspring. Programmes seeking to improve the health and welfare of African migrants in their host countries need to accommodate the cultural and social dimensions that shape their lives. Such programmes may need to be so broad as to apply an acculturation lens to planning, and to assist young people, parents and families in addressing intergenerational issues related to raising children and growing up in a different social and cultural milieu.

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This study documented the parenting styles among African migrants now living in Melbourne, Victoria, Australia, and assessed how intergenerational issues related to parenting in a new culture impact on family functioning and the modification of lifestyles. A total of 10 focus group discussions (five with parents and five with 13–17-year-old children; N = 85 participants) of 1.5–2 hours duration were conducted with Sudanese, Somali and Ethiopian migrant families. The analysis identified three discrete themes: (i) parenting-related issues; (ii) family functioning and family relations; and (iii) lifestyle changes and health. African migrant parents were restrictive in their parenting; controlled children's behaviours and social development through strict boundary-setting and close monitoring of interests, activities, and friends; and adopted a hierarchical approach to decision-making while discouraging autonomy among their offspring. Programmes seeking to improve the health and welfare of African migrants in their host countries need to accommodate the cultural and social dimensions that shape their lives. Such programmes may need to be so broad as to apply an acculturation lens to planning, and to assist young people, parents and families in addressing intergenerational issues related to raising children and growing up in a different social and cultural milieu.

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In the trypsin superfamily of serine proteases, non-trypsin-like primary specificities have arisen in only two monophyletic descendent subbranches. We have recreated an ancestor to one of these subbranches (granzyme) using phylogenetic inference, gene synthesis, and protein expression. This ancestor has two unusual properties. First, it has broad primary specificity encompassing the entire repertoire of novel primary specificities found in its descendents. Second, unlike extant members that have narrow primary specificities, the ancestor exhibits tolerance to mutational changes in primary specificity-conferring residues—that is, structural plasticity. Molecular modeling and mutagenesis studies indicate that these unusual properties are due to a particularly wide substrate binding pocket. These two crucial properties of the ancestor not only distinguish it from its extant descendents but also from the trypsin-like proteases that preceded it. This indicates that a despecialization step, characterized by broad specificity and structural plasticity, underlies evolution of new primary specificities in this protease superfamily.

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Purpose. Although the family environment is a potentially important influence on children's physical activity (PA), prospective data investigating these associations are lacking. This study aimed to examine the longitudinal relationship between the family environment and PA among youth.

Design. A 5-year prospective cohort study.

Setting. Nineteen randomly selected public schools in Melbourne, Australia.

Subjects. Families of 5- to 6-year-old (n  =  190) and 10- to 12-year-old (n  =  350) children.

Measures. In 2001, parents reported their participation in PA, family-based PA, and support and reinforcement for their child's PA. In 2001, 2004, and 2006, moderate to vigorous intensity PA (MVPA) was assessed among youth using accelerometers. Weekend and “critical window” (after school until 6:00 p.m.) MVPA were examined because we hypothesized that the family environment would most likely influence these behaviors.

Analysis. Generalized estimating equations predicted average change in MVPA over 5 years from baseline family environment factors.

Results. Maternal role modeling was positively associated with boys' critical window and weekend (younger boys) MVPA. Paternal reinforcement of PA was positively associated with critical window and weekend MVPA among all boys, and paternal direct support was positively associated with weekend MVPA (older boys). Among girls, maternal coparticipation in PA predicted critical window MVPA, and sibling coparticipation in PA was directly associated with weekend MVPA (younger girls).

Conclusions. Longitudinal relationships, although weak in magnitude, were observed between the family environment and MVPA among youth. Interventions promoting maternal role modeling, paternal reinforcement of and support for PA, and maternal and sibling coparticipation in PA with youth are warranted.

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Objective The evidence for the association between obesity and the risk of type 2 diabetes has been derived mainly from the analysis of the degree of obesity. The role of the duration of obesity as an independent risk has not been fully explored. The objective of the present study was to investigate the association between the duration of obesity and the risk of type 2 diabetes.

Design Prospective cohort study.

Setting The Framingham Heart Study (FHS), follow-up from 1948 to 1998.

Subjects A total of 1256 FHS participants who were free from type 2 diabetes at baseline, but were obese on at least two consecutive of the study’s twenty-four biennial examinations, were included. Type 2 diabetes status was collected throughout the 48 years of follow-up of the study. The relationship between duration of obesity and type 2 diabetes was analysed using time-dependent Cox models, adjusting for a number of covariates.

Results The unadjusted hazard ratio (HR) for the risk of type 2 diabetes for men was 1·13 (95 % CI 1·09, 1·17) and for women was 1·12 (95 % CI 1·08, 1·16) per additional 2-year increase in the duration of obesity. Adjustment for sociodemographic variables, family history of diabetes, health behaviour and physical activity made little difference to these HR. For women the evidence of a dose–response relationship was less clear than for men, particularly for women with an older age at obesity onset.

Conclusions The duration of obesity is a relevant risk factor for type 2 diabetes, independent of the degree of BMI.

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Background
There is increasing community and government recognition of the magnitude and impact of adolescent depression. Family based interventions have significant potential to address known risk factors for adolescent depression and could be an effective way of engaging adolescents in treatment. The evidence for family based treatments of adolescent depression is not well developed. The objective of this clinical trial is to determine whether a family based intervention can reduce rates of unipolar depressive disorders in adolescents, improve family functioning and engage adolescents who are reluctant to access mental health services.

Methods/Design
The Family Options study will determine whether a manualized family based intervention designed to target both individual and family based factors in adolescent depression (BEST MOOD) will be more effective in reducing unipolar depressive disorders than an active (standard practice) control condition consisting of a parenting group using supportive techniques (PAST). The study is a multicenter effectiveness randomized controlled trial. Both interventions are delivered in group format over eight weekly sessions, of two hours per session. We will recruit 160 adolescents (12 to 18 years old) and their families, randomized equally to each treatment condition. Participants will be assessed at baseline, eight weeks and 20 weeks. Assessment of eligibility and primary outcome will be conducted using the KID-SCID structured clinical interview via adolescent and parent self-report. Assessments of family mental health, functioning and therapeutic processes will also be conducted. Data will be analyzed using Multilevel Mixed Modeling accounting for time x treatment effects and random effects for group and family characteristics. This trial is currently recruiting. Challenges in design and implementation to-date are discussed. These include diagnosis and differential diagnosis of mental disorders in the context of adolescent development, non-compliance of adolescents with requirements of assessment, questionnaire completion and treatment attendance, breaking randomization, and measuring the complexity of change in the context of a family-based intervention.

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Smartphones are pervasively used in society, and have been both the target and victim of malware writers. Motivated by the significant threat that presents to legitimate users, we survey the current smartphone malware status and their propagation models. The content of this paper is presented in two parts. In the first part, we review the short history of mobile malware evolution since 2004, and then list the classes of mobile malware and their infection vectors. At the end of the first part, we enumerate the possible damage caused by smartphone malware. In the second part, we focus on smartphone malware propagation modeling. In order to understand the propagation behavior of smartphone malware, we recall generic epidemic models as a foundation for further exploration. We then extensively survey the smartphone malware propagation models. At the end of this paper, we highlight issues of the current smartphone malware propagation models and discuss possible future trends based on our understanding of this topic. © © 2014 IEEE.

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PURPOSE: Despite its official acceptance as an important physician responsibility, health advocacy remains difficult to define, teach, role model, and assess. The aim of the current study was to explore physicians' conceptions of health advocacy based on their experience with health-advocacy-related activities. METHOD: In 2012, the authors conducted 11 semistructured interviews with family physician clinical preceptors and analyzed the interviews in the tradition of phenomenography. RESULTS: The authors identified three distinct but related ways of understanding health advocacy: (1) Clinical: Health advocacy as support of individual patients in addressing health care needs related to the immediate clinical problem within the health care system, (2) Paraclinical: Health advocacy as support of individual patients in addressing needs that the physician preceptors viewed as peripheral yet parallel to both the health care system and the immediate clinical problem, and (3) Supraclinical: Health advocacy as population-based activities aimed at practice- and system-level changes that address the social determinants of health. CONCLUSIONS: The qualitatively different understandings of health advocacy shed light on why current approaches to defining, teaching, role modeling, and assessing health advocacy competencies in medical education appear idiosyncratic. The authors suggest the development of an inclusive and extensive conceptual framework that may allow the medical education community to imagine novel ways of understanding and engaging in health advocacy.

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Distributed energy and water balance models require time-series surfaces of the meteorological variables involved in hydrological processes. Most of the hydrological GIS-based models apply simple interpolation techniques to extrapolate the point scale values registered at weather stations at a watershed scale. In mountainous areas, where the monitoring network ineffectively covers the complex terrain heterogeneity, simple geostatistical methods for spatial interpolation are not always representative enough, and algorithms that explicitly or implicitly account for the features creating strong local gradients in the meteorological variables must be applied. Originally developed as a meteorological pre-processing tool for a complete hydrological model (WiMMed), MeteoMap has become an independent software. The individual interpolation algorithms used to approximate the spatial distribution of each meteorological variable were carefully selected taking into account both, the specific variable being mapped, and the common lack of input data from Mediterranean mountainous areas. They include corrections with height for both rainfall and temperature (Herrero et al., 2007), and topographic corrections for solar radiation (Aguilar et al., 2010). MeteoMap is a GIS-based freeware upon registration. Input data include weather station records and topographic data and the output consists of tables and maps of the meteorological variables at hourly, daily, predefined rainfall event duration or annual scales. It offers its own pre and post-processing tools, including video outlook, map printing and the possibility of exporting the maps to images or ASCII ArcGIS formats. This study presents the friendly user interface of the software and shows some case studies with applications to hydrological modeling.

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Desenvolvemos modelos de ajuste parcial e de duration para testar a relevância de fatores específicos de países na determinação da estrutura de capital de empresas listadas nas bolsas de valores brasileira, chilena e mexicana. Utilizamos dados em painel, em um período que se estende do quarto trimestre de 1996 ao segundo trimestre de 2010, abrangendo 4403 observações relacionadas a 139 empresas diferentes. Os resultados obtidos sugerem que a dinâmica da estrutura de capital varia por país e que idiossincrasias locais são determinantes-chave dos níveis de alavancagem das empresas. Não detectamos comportamento explicado pela Teoria de Trade Off entre as empresas brasileiras, chilenas e mexicanas, o que indica que teorias alternativas possam comandar os processos de decisão de financiamento dos gestores latino americanos.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The complete nucleotide sequence of a nerve growth factor precursor from Bothrops jararacussu snake (Bj-NGF) was determined by DNA sequencing of a clone from cDNA library prepared from the poly(A) + RNA of the venom gland of B.jararacussu. cDNA encoding Bj-NGF precursor contained 723 bp in length, which encoded a prepro-NGF molecule with 241 amino acid residues. The mature Bj-NGF molecule was composed of I 18 amino acid residues with theoretical pI and molecular weight of 8.31 and 13,537, respectively. Its amino acid sequence showed 97%, 96%, 93%, 86%, 78%, 74%, 76%, 76% and 55% sequential similarities with NGFs from Crotalus durissus terrificus, Agkistrodon halys pallas, Daboia (Vipera) russelli russelli, Bungarus multicinctus, Naja sp., mouse, human, bovine and cat, respectively. Phylogenetic analyses based on the amino acid sequences of 15 NGFs separate the Elapidae family (Naja and Bungarus) from those Crotalidae snakes (Bothrops, Crotalus and Agkistrodon). The three-dimensional structure of mature Bj-NGF was modeled based on the crystal structure of the human NGF. The model reveals that the core of NGF, formed by a pair of P-sheets, is highly conserved and the major mutations are both at the three beta-hairpin loops and at the reverse turn. (C) 2002 Societe francaise de biochimie et biologic moleculaire/Editions scientifiques et medicales Elsevier SAS. All rights reserved.