615 research outputs found

    The management of de-cumulation risks in a defined contribution environment

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    The aim of the paper is to lay the theoretical foundations for the construction of a flexible tool that can be used by pensioners to find optimal investment and consumption choices in the distribution phase of a defined contribution pension scheme. The investment/consumption plan is adopted until the time of compulsory annuitization, taking into account the possibility of earlier death. The effect of the bequest motive and the desire to buy a higher annuity than the one purchasable at retirement are included in the objective function. The mathematical tools provided by dynamic programming techniques are applied to find closed form solutions: numer-ical examples are also presented. In the model, the trade-off between the different desires of the individual regarding consumption and final annuity can be dealt with by choosing appropriate weights for these factors in the setting of the problem. Conclusions are twofold. Firstly, we find that there is a natural time-varying target for the size of the fund, which acts as a sort of safety level for the needs of the pensioner. Secondly, the personal preferences of the pensioner can be translated into optimal choices, which in turn affect the distribution of the consumption path and of the final annuity

    From Theory to Practice: Plug and Play with Succinct Data Structures

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    Engineering efficient implementations of compact and succinct structures is a time-consuming and challenging task, since there is no standard library of easy-to- use, highly optimized, and composable components. One consequence is that measuring the practical impact of new theoretical proposals is a difficult task, since older base- line implementations may not rely on the same basic components, and reimplementing from scratch can be very time-consuming. In this paper we present a framework for experimentation with succinct data structures, providing a large set of configurable components, together with tests, benchmarks, and tools to analyze resource requirements. We demonstrate the functionality of the framework by recomposing succinct solutions for document retrieval.Comment: 10 pages, 4 figures, 3 table

    Opioid overdose risk during and after drug treatment for heroin dependence: An incidence density case–control study nested in the VEdeTTE cohort

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    Introduction and Aims: To corroborate protective effects of a range of drug treatment modalities against overdose mortality risk. Design and Methods: Nested case–control study, with incidence density sampling, selecting controls retrospectively at each case event. Cases and controls came from a sub-cohort of opioid-dependent patients (n = 4444) from two Italian regions (Lazio and Piedmont). From 1998 to 2005, there were 91 overdose deaths (cases) matched to 352 controls. The primary outcome was overdose mortality and the primary exposure was drug treatment: opioid agonist treatment (OAT), opioid detoxification, residential community, psychosocial and other pharmacological treatment. Conditional logistic regression models generated intervention effects comparing mortality risk in and out of treatment, adjusting for confounding variables. Results: Overall, drug treatment reduced overdose mortality risk by 80% [adjusted odds ratio (AOR) 0.18, 95% confidence interval (CI) 0.10–0.33, P < 0.001] compared to being out of treatment. There was a particularly strong protective effect of OAT on overdose mortality (AOR 0.08, 95% CI 0.03–0.23, P < 0.001) compared to being out of treatment. There was evidence of a substantially elevated risk of overdose in the first month of leaving treatment (AOR 23.50, 95% CI 7.84–70.19, P < 0.001) compared to being in treatment. Discussion and Conclusions: The nested case–control design strengthened earlier findings that OAT in Italy has strong protective effects on overdose mortality risk, much stronger than has been previously seen in other Western European settings

    met overexpression turns human primary osteoblasts into osteosarcomas

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    The MET oncogene was causally involved in the pathogenesis of a rare tumor, i.e., the papillary renal cell carcinoma, in which activating mutations, either germline or somatic, were identified. MET activating mutations are rarely found in other human tumors, whereas at higher frequencies, MET is amplified and/or overexpressed in sporadic tumors of specific histotypes, including osteosarcoma. In this work, we provide experimental evidence that overexpression of the MET oncogene causes and sustains the full-blown transformation of osteoblasts. Overexpression of MET , obtained by lentiviral vector–mediated gene transfer, resulted in the conversion of primary human osteoblasts into osteosarcoma cells, displaying the transformed phenotype in vitro and the distinguishing features of human osteosarcomas in vivo . These included atypical nuclei, aberrant mitoses, production of alkaline phosphatase, secretion of osteoid extracellular matrix, and striking neovascularization. Although with a lower tumorigenicity, this phenotype was superimposable to that observed after transfer of the MET gene activated by mutation. Both transformation and tumorigenesis were fully abrogated when MET expression was quenched by short-hairpin RNA or when signaling was impaired by a dominant-negative MET receptor. These data show that MET overexpression is oncogenic and that it is essential for the maintenance of the cancer phenotype. (Cancer Res 2006; 66(9): 4750-7

    Improving procedural fidelity of behavioural interventions for people with intellectual and developmental disabilities: A systematic review

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    Background: Despite its importance within behavioural intervention, it remains unclear how best to achieve high procedural fidelity. This paper reviewed studies on improving procedural fidelity of behavioural interventions for individuals with intellectual and developmental disabilities (IDD). Method: A systematic literature search was conducted, which identified 20 studies meeting inclusion criteria. Data were extracted on study design, participant characteristics, intervention, target behaviours, effect sizes, maintenance, generalisation, and social validity. A quality rating was also applied. Results: A total of 100 participants took part in the included studies. Most participants were teachers working with children in school settings. There was a significant positive correlation between level of procedural fidelity and client outcomes. Feedback was the most commonly employed intervention to improve procedural fidelity. Conclusions: More research should be conducted in environments with high levels of variability such as community homes to determine how to reach and maintain high levels of procedural fidelity

    The +276 G/T Single Nucleotide Polymorphism of the Adiponectin Gene Is Associated With Coronary Artery Disease in Type 2 Diabetic Patients

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    OBJECTIVE —Two single nucleotide polymorphisms (SNPs) at the adiponectin locus (+45T>G and +276G>T) have been associated with low circulating adiponectin levels, insulin resistance, and type 2 diabetes. We investigated whether these genetic markers are determinants of coronary artery disease (CAD) in type 2 diabetic patients. RESEARCH DESIGN AND METHODS —A total of 376 consecutive type 2 diabetic patients were studied: 142 case subjects with coronary stenosis >50% or previous myocardial infarction and 234 control subjects with no symptoms, no electrocardiogram (ECG) signs of myocardial ischemia, and a normal ECG stress test ( n = 189) and/or ( n = 45) with coronary stenosis ≤50%. RESULTS —No association with CAD was observed for the +45 SNP ( P = 0.48). By contrast, a significant association was observed for the +276 SNP, with T/T homozygotes having a lower risk of CAD than carriers of other genotypes (adjusted odds ratio [OR] 0.13 [95% CI 0.037–0.46], P = 0.002). A similarly protective effect of the +276 T/T genotype was observed in 110 case and 45 control subjects for whom the CAD status had been determined by angiography (0.04 [0.006–0.30], P = 0.002).  Serum adiponectin, although clearly related to several features of the proatherogenic/insulin-resistant phenotype, was not different between control subjects and CAD patients (26 ± 17 vs. 25 ± 13 μg/ml). CONCLUSIONS —In conclusion, the +276 G>T polymorphism is a determinant of CAD risk in type 2 diabetic patients. This marker may assist in the identification of diabetic individuals at especially high risk of CAD, so that preventive programs can be targeted at these subjects

    Desafios da operacionalização do biorreator com inóculo mesofílico.

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    O desenvolvimento do processo de biodigestão com foco em resíduos agropecuários é uma forma de gerar renda no campo, ao gerar energia e fertilizante, e ao mesmo tempo destinar de forma ambientalmente correta os resíduos gerados em suas atividades, inserindo&#8209;se na bioeconomia e na descarbonização da economia. Contudo, para a realização de estudos de biodigestão, são importantes a origem e a reprodutibilidade do inóculo utilizado nos experimentos. Nesse contexto, foi necessário montar e operacionalizar um biodigestor para produção de inóculo de 160 L, com 120 L de inóculo inicialmente composto por digestato de biodigestor oriundo da suinocultura (80%) e de dejeto bruto bovino (20%). Na operação desse biodigestor, foi implementada uma série de métodos para acompanhar as variáveis de processo relevantes, tais como pH, alcalinidade, sólidos voláteis, sólidos totais, demanda química de oxigênio, nitrogênio total Kjeldahl, nitrogênio amoniacal e produção de metano, para assim assegurar uma operação contínua e estável do processo de biodigestão

    Desenvolvimento de biodigestor automatizado para produção de inóculo.

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    A manutenção de uma fonte estável de inóculo é imprescindível para a obtenção de resultados experimentais reprodutíveis e confiáveis no desenvolvimento de pesquisas relacionadas com o processo de biodigestão, principalmente em razão do grande tempo necessário, medido em semanas, para o desenvolvimento e a estabilização dos microrganismos que fazem conversão da matéria orgânica em biogás. Dessa forma, faz&#8209;se necessária a utilização de um biodigestor onde seja possível estabelecer um estado estacionário dos microrganismos presentes no reator, e que eles estejam em condições de se desenvolver assim que inoculados em outros frascos ou bioreatores. O presente trabalho trata da montagem de um biodigestor com controle de temperatura e agitação, e medição do biogás produzido, visando à produção estável de inóculo
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