512 research outputs found

    Forecasting age-specific breast cancer mortality using functional data models

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    Accurate estimates of future age-specific incidence and mortality are critical for allocation of resources to breast cancer control programs and evaluation of screening programs. The purpose of this study is to apply functional data analysis techniques to model age-specific breast cancer mortality time trends, and forecast entire age-specific mortality function using a state-space approach. We use yearly unadjusted breast cancer mortality rates in Australia, from 1921 to 2001 in 5 year age groups (45 to 85+). We use functional data analysis techniques where mortality and incidence are modeled as curves with age as a functional covariate varying by time. Data is smoothed using nonparametric smoothing methods then decomposed (using principal components analysis) to estimate basis functions that represent the functional curve. Period effects from the fitted functions are forecast then multiplied by the basis functions, resulting in a forecast mortality curve with prediction intervals. To forecast, we adopt a state-space approach and an extension of the Pegels modeling framework for selecting among exponential smoothing methods. Overall, breast cancer mortality rates in Australia remained relatively stable from 1960 to the late 1990's but declined over the last few years. A set of K=4 basis functions minimized the mean integrated squared forecasting error (MISFE) and accounts for 99.3% of variation around the mean mortality curve. 20 year forecast suggest a continual decline at a slower rate and stabilize beyond 2010 and by age, forecasts show a decline in all age groups with the greatest decline in older women. We illustrate the utility of a new modelling and forecasting approach to model breast cancer mortality rates using a functional model of age. The methods have the potential to incorporate important covariates such as Hormone Replacement Therapy (HRT) and interventions to represent mammographic screening. This would be particularly useful for evaluating the impact of screening on mortality and incidence from breast cancer.Mortality, Breast Cancer, Forecasting, Functional Data Analysis, Exponential Smoothing

    Child mental health after parental separation: the impact of resident/non-resident parenting, parent mental health, conflict and socioeconomics.

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    Children of separated parents are consistently shown to have greater likelihood of poor mental health than children of intact families. Explanations to date have focussed on the impacts of parental conflict, and the role of resident mothers, neglecting the potential importance of non-resident fathers. Using recent data from the Longitudinal Study of Australian Children, this study 1) compares the mental health of children from intact families with resident fathers to those from separated families with non-resident fathers and 2) explores predictors of poor mental health among children from separated families. Children from separated families had poorer mental health than those from intact families, but this difference was explained fully by exposure to parental conflict, socioeconomic status and parent mental health, and to a lesser extent by parenting practices. Among children from separated families, the strongest predictor of child mental health was maternal parenting consistency. Policy implications are discussed

    Higher-order corrections to the short-pulse equation

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    Using renormalization group techniques, we derive an extended short- pulse equation as approximation to a nonlinear wave equation. We investigate the new equation numerically and show that the new equation captures efficiently higher- order effects on pulse propagation in cubic nonlinear media. We illustrate our findings using one- and two-soliton solutions of the first-order short-pulse equation as initial conditions in the nonlinear wave equation

    Non-covalent functionalized SWNTs as delivery agents for novel Bodipy-based potential PDT sensitizers

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    Pyrenyl-functionalized distyryl-Bodipy sensitizer attached non-covalently to SWNTs was shown to generate singlet oxygen when excited at 660 nm with a red LED array; this work emphasizes the potential of SWNT as a viable alternative carrier of bioactive agents, including photodynamic therapy sensitizers. © 2009 The Royal Society of Chemistry

    Trans-disciplinary research in synthesis of grass pollen aerobiology and its importance for respiratory health in Australasia

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    © 2015 Published by Elsevier B.V. Grass pollen is a major trigger for allergic rhinitis and asthma, yet little is known about the timing and levels of human exposure to airborne grass pollen across Australasian urban environments. The relationships between environmental aeroallergen exposure and allergic respiratory disease bridge the fields of ecology, aerobiology, geospatial science and public health. The Australian Aerobiology Working Group comprised of experts in botany, palynology, biogeography, climate change science, plant genetics, biostatistics, ecology, pollen allergy, public and environmental health, and medicine, was established to systematically source, collate and analyse atmospheric pollen concentration data from 11 Australian and six New Zealand sites. Following two week-long workshops, post-workshop evaluations were conducted to reflect upon the utility of this analysis and synthesis approach to address complex multidisciplinary questions. This Working Group described i) a biogeographically dependent variation in airborne pollen diversity, ii) a latitudinal gradient in the timing, duration and number of peaks of the grass pollen season, and iii) the emergence of new methodologies based on trans-disciplinary synthesis of aerobiology and remote sensing data. Challenges included resolving methodological variations between pollen monitoring sites and temporal variations in pollen datasets. Other challenges included "marrying" ecosystem and health sciences and reconciling divergent expert opinion. The Australian Aerobiology Working Group facilitated knowledge transfer between diverse scientific disciplines, mentored students and early career scientists, and provided an uninterrupted collaborative opportunity to focus on a unifying problem globally. The Working Group provided a platform to optimise the value of large existing ecological datasets that have importance for human respiratory health and ecosystems research. Compilation of current knowledge of Australasian pollen aerobiology is a critical first step towards the management of exposure to pollen in patients with allergic disease and provides a basis from which the future impacts of climate change on pollen distribution can be assessed and monitored

    Multiobjective optimization of MPLS-IP networks with a variable neighborhood genetic algorithm

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    This paper presents a Genetic Algorithm for the optimization of multiple indices of Quality of Service of Multi Protocol Label Switching (MPLS) IP networks. The proposed algorithm, the Variable Neighborhood Multiobjective Genetic Algorithm (VN-MGA), is a Genetic Algorithm based on the NSGA-II, with the particular feature that solutions are encoded defining two different kinds of neighborhoods. The first neighborhood is defined by considering as decision variables the edges that form the routes to be followed by each request, whilst the second part of solution is kept constant. The second neighborhood is defined by considering the request sequence as decision variable, with the first part kept constant. Comparisons are performed with: (i) a VNS algorithm that performs a switch between the same two neighborhoods that are used in VN-MGA; and (ii) the results obtained with an integer linear programming solver, running a scalarized version of the multiobjective problem. The results indicate that the proposed VN-MGA outperforms the pure VNS algorithm, and provides a good approximation of the exact Pareto fronts obtained with Integer Linear Programming (ILP) approach, at a much smaller computational cost. Besides potential benefits of the application of the proposed approach to the optimization of packet routing in MPLS networks, this work raises the theoretical issue of the systematic application of variable encodings, which allow variable neighborhood searches, as generic operators inside general evolutionary computation algorithms. Codice rivista: E013138 Titolo rivista: APPLIED SOFT COMPUTING Issn: 1568-4946 Cordiali saluti CINECA - Servizio Gestione Rivist

    Sex-Specific Clinical Outcomes of the PACT-HF Randomized Trial

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    BACKGROUND: Transitional care may have different effects in males and females hospitalized for heart failure. We assessed the sex-specific effects of a transitional care model on clinical outcomes following hospitalization for heart failure. METHODS: In this stepped-wedge cluster randomized trial of adults hospitalized for heart failure in Ontario, Canada, 10 hospitals were randomized to a group of transitional care services or usual care. Outcomes in this exploratory analysis were composite all-cause readmission, emergency department visit, or death at 6 months; and composite all-cause readmission or emergency department visit at 6 months. Models were adjusted for stepped-wedge design and patient age. RESULTS: Among 2494 adults, mean (SD) age was 77.7 (12.1) years, and 1258 (50.4%) were female. The first composite outcome occurred in 371 (66.3%) versus 433 (64.1%) males (hazard ratio [HR], 1.04 [95% CI, 0.86-1.26]; P=0.67) and in 326 (59.9%) versus 463 (64.8%) females (HR, 0.83 [95% CI, 0.69-1.01]; P=0.06) in the intervention and usual care groups, respectively (P=0.012 for sex interaction). The second composite outcome occurred in 357 (63.8%) versus 417 (61.7%) males (HR, 1.03 [95% CI, 0.85-1.24]; P=0.76) and 314 (57.7%) versus 450 (63.0%) females (HR, 0.81 [95% CI, 0.67-0.99]; P=0.037) in the intervention and usual care groups, respectively (P=0.024 for sex interaction). The sex differences were driven by a reduction in all-cause emergency department visits among females (HR, 0.66 [95% CI, 0.51-0.87]; P=0.003), but not males (HR, 1.10 [95% CI, 0.85-1.43]; P=0.46), receiving the intervention (P<0.001 for sex interaction). CONCLUSIONS: A transitional care model offered a reduction in all-cause emergency department visits among females but not males following hospitalization for heart failure. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02112227

    A 32‐society investigation of the influence of perceived economic inequality on social class stereotyping

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    There is a growing body of work suggesting that social class stereotypes are amplified when people perceive higher levels of economic inequality—that is, the wealthy are perceived as more competent and assertive and the poor as more incompetent and unassertive. The present study tested this prediction in 32 societies and also examines the role of wealth-based categorization in explaining this relationship. We found that people who perceived higher economic inequality were indeed more likely to consider wealth as a meaningful basis for categorization. Unexpectedly, however, higher levels of perceived inequality were associated with perceiving the wealthy as less competent and assertive and the poor as more competent and assertive. Unpacking this further, exploratory analyses showed that the observed tendency to stereotype the wealthy negatively only emerged in societies with lower social mobility and democracy and higher corruption. This points to the importance of understanding how socio-structural features that co-occur with economic inequality may shape perceptions of the wealthy and the poor.info:eu-repo/semantics/publishedVersio
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