871 resultados para Information in biology
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This paper describes the methodology, results and limitations of the 2013 International Diabetes Federation (IDF) Atlas (6th edition) estimates of the worldwide numbers of prevalent cases of type 1 diabetes in children (<15 years). The majority of relevant information in the published literature is in the form of incidence rates derived from registers of newly diagnosed cases. Studies were graded on quality criteria and, if no information was available in the published literature, extrapolation was used to assign a country the rate from an adjacent country with similar characteristics. Prevalence rates were then derived from these incidence rates and applied to United Nations 2012 Revision population estimates for 2013 for each country to obtain estimates of the number of prevalent cases. Data availability was highest for the countries in Europe (76%) and lowest for the countries in sub-Saharan Africa (8%). The prevalence estimates indicate that there are almost 500,000 children aged under 15 years with type 1 diabetes worldwide, the largest numbers being in Europe (129,000) and North America (108,700). Countries with the highest estimated numbers of new cases annually were the United States (13,000), India (10,900) and Brazil (5000). Compared with the prevalence estimates made in previous editions of the IDF Diabetes Atlas, the numbers have increased in most of the IDF Regions, often reflecting the incidence rate increases that have been well-documented in many countries. Monogenic diabetes is increasingly being recognised among those with clinical features of type 1 or type 2 diabetes as genetic studies become available, but population-based data on incidence and prevalence show wide variation due to lack of standardisation in the studies. Similarly, studies on type 2 diabetes in childhood suggest increased incidence and prevalence in many countries, especially in Indigenous peoples and ethnic minorities, but detailed population-based studies remain limited.
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Chronic lymphocytic leukemia (CLL) follows a variable clinical course which is difficult to predict at diagnosis. We assessed somatic mutation (SHM) status, CD38 and ZAP-70 expression in 87 patients (49 male, 38 female) with stage A CLL and known cytogenetic profile to compare their role in predicting disease progression, which was assessed by the treatment free interval (TFI) from diagnosis. Sixty (69%) patients were SHM+, 24 (28%) were CD38+ and ten (12%) were ZAP-70+. The median TFI for: (i) SHM + versus SHM- patients was 124 versus 26 months; hazard ratio (HR) = 3.6 [95% confidence interval (CI) = 1.8 - 7.3; P = 0.001]: (ii) CD38- versus CD38+ patients was 120 versus 34 months; HR = 2.4 (95% CI = 1.4 - 5.3; P = 0.02); and (iii) ZAP70- versus ZAP70+ was 120 versus 16 months; HR = 3.4 (95% CI = 1.4 - 8.7; P = 0.01). SHM status and CD38 retained prognostic significance on multivariate analysis whereas ZAP-70 did not. We conclude that ZAP-70 analysis does not provide additional prognostic information in this group of patients.
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Purpose
The study contributes to the literature on public value and performance examining politicians’ and managers’ perspectives by investigating the importance they attach to the different facets of performance information (i.e. budgetary, accrual based- and non-financial information (NFI)).
Design/methodology/approach
We survey politicians and managers in all Italian municipalities of at least 80,000 inhabitants.
Findings
Overall, NFI is more appreciated than financial information (FI). Moreover, budgetary accounting is preferred to accrual accounting. Politicians’ and managers’ preferences are generally aligned.
Research limitations/implications
NFI as a measure of public value is not alternative, but rather complementary, to FI. The latter remains a fundamental element of public sector accounting due to its role in resource allocation and control.
Practical implications
The preference for NFI over FI and of budgetary over accruals accounting suggests that the current predominant emphasis on (accrual-based) financial reporting might be misplaced.
Originality/value
Public value and performance are multi-faceted concepts. They can be captured by different types of information and evaluated according to different criteria, which will also depend on the category of stakeholders or users who assesses public performance. So far, most literature has considered the financial and non-financial facets of performance as virtually separate. Similarly, in the practice, financial management tends to be decoupled from non-financial performance management. However, this research shows that only by considering their joint interactions we can achieve an accurate representation of what public value really is.
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Background: Large-scale biological jobs on high-performance computing systems require manual intervention if one or more computing cores on which they execute fail. This places not only a cost on the maintenance of the job, but also a cost on the time taken for reinstating the job and the risk of losing data and execution accomplished by the job before it failed. Approaches which can proactively detect computing core failures and take action to relocate the computing core's job onto reliable cores can make a significant step towards automating fault tolerance. Method: This paper describes an experimental investigation into the use of multi-agent approaches for fault tolerance. Two approaches are studied, the first at the job level and the second at the core level. The approaches are investigated for single core failure scenarios that can occur in the execution of parallel reduction algorithms on computer clusters. A third approach is proposed that incorporates multi-agent technology both at the job and core level. Experiments are pursued in the context of genome searching, a popular computational biology application. Result: The key conclusion is that the approaches proposed are feasible for automating fault tolerance in high-performance computing systems with minimal human intervention. In a typical experiment in which the fault tolerance is studied, centralised and decentralised checkpointing approaches on an average add 90% to the actual time for executing the job. On the other hand, in the same experiment the multi-agent approaches add only 10% to the overall execution time
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Wavelet entropy assesses the degree of order or disorder in signals and presents this complex information in a simple metric. Relative wavelet entropy assesses the similarity between the spectral distributions of two signals, again in a simple metric. Wavelet entropy is therefore potentially a very attractive tool for waveform analysis. The ability of this method to track the effects of pharmacologic modulation of vascular function on Doppler blood velocity waveforms was assessed. Waveforms were captured from ophthalmic arteries of 10 healthy subjects at baseline, after the administration of glyceryl trinitrate (GTN) and after two doses of N(G)-nitro-L-arginine-methyl ester (L-NAME) to produce vasodilation and vasoconstriction, respectively. Wavelet entropy had a tendency to decrease from baseline in response to GTN, but significantly increased after the administration of L-NAME (mean: 1.60 ± 0.07 after 0.25 mg/kg and 1.72 ± 0.13 after 0.5 mg/kg vs. 1.50 ± 0.10 at baseline, p < 0.05). Relative wavelet entropy had a spectral distribution from increasing doses of L-NAME comparable to baseline, 0.07 ± 0.04 and 0.08 ± 0.03, respectively, whereas GTN had the most dissimilar spectral distribution compared with baseline (0.17 ± 0.08, p = 0.002). Wavelet entropy can detect subtle changes in Doppler blood velocity waveform structure in response to nitric-oxide-mediated changes in arteriolar smooth muscle tone.
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This article presents the results from an analysis of data from service providers and young adults who were formerly in state care about how information about the sexual health of young people in state care is managed. In particular, the analysis focuses on the perceived impact of information sharing between professionals on young people. Twenty-two service providers from a range of professions including social work, nursing and psychology, and 19 young people aged 18–22 years who were formerly in state care participated in the study. A qualitative approach was employed in which participants were interviewed in depth and data were analysed using modified analytical induction (Bogdan & Biklen, 2007). Findings suggest that within the care system in which service provider participants worked it was standard practice that sensitive information about a young person’s sexual health would be shared across team members, even where there appeared to be no child protection issues. However, the accounts of the young people indicated that they experienced the sharing of information in this way as an invasion of their privacy. An unintended outcome of a high level of information sharing within teams is that the privacy of the young person in care is compromised in a way that is not likely to arise in the case of young people who are not in care. This may deter young people from availing themselves of the sexual health services.
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Os desenvolvimentos associados à medicina genómica e biologia molecular representam novas possibilidades no diagnóstico, tratamento e prevenção de doenças comuns, confrontando indivíduos e famílias com complexos desafios à integração da informação genética na gestão da saúde e nas suas vidas. Este estudo centra-se em famílias com suscetibilidade genética acrescida a cancros hereditários e pretende contribuir para o conhecimento da experiência individual e familiar do aconselhamento oncogenético, incluindo como pode ser contemplada no desenvolvimento de intervenções de apoio psicossocial e na organização dos cuidados de saúde na era (pós)genómica. O processo de investigação incorpora perspetivas da genética psicossocial e da teoria dos sistemas familiares. Engloba metodologias qualitativas de recolha e análise de dados, envolvendo indivíduos, famílias e profissionais de saúde num formato de investigação-ação participativa. Os principais resultados permitem: i) conceptualizar a experiência do aconselhamento oncogenético, através da caracterização das suas implicações instrumentais, emocionais, relacionais e desenvolvimentais para o indivíduo e sistema familiar; ii) conhecer o desenvolvimento, implementação e avaliação de um programa psicoeducativo multifamiliar, enquanto intervenção de apoio psicossocial a indivíduos com suscetibilidade acrescida a cancros hereditários e suas famílias; e iii) integrar a perspetiva dos profissionais de saúde quanto à incorporação de apoio psicossocial na provisão dos serviços oncogenéticos. As conclusões gerais sustentam a importância do aprofundamento da pesquisa sobre o funcionamento familiar face ao aconselhamento e risco oncogenético, e a incorporação de uma orientação familiar nesses serviços. As implicações decorrentes da suscetibilidade acrescida a doenças genéticas impõem uma discussão alargada aos vários agentes envolvidos no planeamento, provisão e utilização dos cuidados de saúde, no sentido do desenvolvimento de serviços atuantes no continuum biopsicossocial indivíduofamília- sistema de saúde-comunidade.
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À semelhança do que aconteceu em muitas instituições públicas, as universidades têm enfrentado pressões crescentes para mudar, tendo de repensar as suas formas de governança e de gestão, dando mais ênfase à implementação de sistemas de gestão do desempenho (SGD). Apesar de existirem vários estudos sobre o desempenho, estes têm ignorado o uso dado à informação recolhida. Além disso, e apesar de terem ocorrido várias reformas na governança destas instituições, existem ainda poucos estudos que relacionam a governança e o desempenho. Assim, esta pesquisa visa explorar a forma como as universidades medem, reportam e gerem o desempenho e como as estruturas de governança se relacionam com estas práticas. Para alcançar o objetivo proposto, um estudo comparativo entre universidades britânicas e portuguesas foi realizado. Os dados foram recolhidos através da utilização de uma metodologia qualitativa, sendo os métodos utilizados a análise documental e entrevistas semi-estruturadas a membros dos órgãos de governo e gestão de cada instituição. A análise dos dados mostrou a inexistência de um sistema completamente integrado de gestão de desempenho (SGD) em ambas as instituições, essencialmente devido à falta de práticas de gestão de desempenho. De facto, apesar de alguns dos entrevistados terem reportado o "uso positivo" de dados sobre o desempenho, alguns relataram o "não uso" desses dados, principalmente em relação ao desempenho individual, e outros o "mau uso" dessa informação, tendo sido reportadas práticas de gaming e deturpação dos resultados. Como forma de ultrapassar alguns destes problemas, verificou-se a co-existência de duas estruturas de governança: uma 'formal', da qual fazem parte todos os órgão de governo, com um valor mais 'simbólico'; e uma estrutura 'paralela', constituída por órgãos mais ágeis, que gerem a universidade no dia a dia. Verificou-se terem sido vários os fatores a afetarem, negativa e positivamente, os SGD em ambas as instituições, tendo sido rotulados de "inibidores" e "determinantes", respetivamente. A pesquisa mostrou que, apesar de as estruturas de governança serem importantes para a implementação e funcionamento de um SGD, há outros fatores que precisam de ser levados em consideração, nomeadamente, o nível de comunicação e o nível de envolvimento dos atores no processo. Estes dois fatores são considerados relevantes para a integração bem sucedida de práticas de medição, reporte e gestão de desempenho. Esta integração, juntamente com outras mudanças que ocorreram em termos de governança, contribuirá certamente para que se passe de um sistema em que se governa o desempenho para um sistema em que se governa para o desempenho.
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Em Portugal, o tirame é um dos fungicidas mais utilizados, cujas vendas aumentaram significativamente nos últimos anos, sendo também um dos fungicidas mais utilizados em todo o mundo. No entanto, em comparação com outros pesticidas, existe falta de informação na literatura sobre o seu comportamento em sistemas ambientais, nomeadamente, no que diz respeito à sua degradação no solo ou em águas e produtos a que dá origem. Neste contexto, o objetivo deste trabalho foi estudar a influência das substâncias húmicas e iões cobre no comportamento e destino do tirame no meio ambiente. Foram realizados vários estudos para analisar o comportamento do tirame em solos com diferentes conteúdos de matéria orgânica e de iões cobre, e em águas naturais, estudando como as substâncias húmicas, os iões cobre e a luz solar podem afetar a sua degradação. Os estudos de adsorção-desadsorção do tirame nos solos revelaram que a matéria orgânica do solo e o conteúdo de cobre afetavam os processos de adsorção-desadsorção do tirame, influenciando a sua lixiviação e persistência no solo. De facto, verificou-se que o teor de cobre do solo tinha um efeito bastante marcante no processo de adsorçãodesadsorção do tirame. Verificou-se a ocorrência de reações entre o tirame e os iões cobre, cuja extensão durante os estudos de adsorção pode ser fortemente dependente do teor de cobre do solo e da concentração inicial de tirame em solução. Assim, a escolha do tempo de equilíbrio em estudos de adsorção e a determinação das isotérmicas de adsorção ao solo torna-se uma tarefa difícil. Além disso, os complexos formados com o cobre existente no solo são persistentes, não sendo facilmente lixiviados para as águas subterrâneas. Conclui-se que os iões cobre(II) podem contribuir para a imobilização do tirame no solo e o aumento da persistência dos seus resíduos ligados ao cobre. A partir de estudos de recuperação do tirame em águas naturais verificou-se a ocorrência de uma rápida degradação do tirame, devido provavelmente aos iões metálicos, nomeadamente, iões cobre. Verificou-se que dependendo da razão tirame:Cu podiam ocorrer dois processos: (i) complexação entre o tirame e o cobre, quando não há excesso de iões cobre, sendo o complexo formado mais persistente que o tirame; (ii) ou, quando há um grande excesso de iões cobre, a degradação do tirame e a estabilização dos produtos de degradação por complexação, podendo formar-se complexos que permanecem sem alteração em solução durante pelo menos dois meses. No geral, foi possível, pela primeira vez, identificar alguns dos complexos de cobre formados ao longo do tempo. Por fim, estudou-se a cinética de fotodegradação do tirame em solução aquosa sob a ação da luz solar e identificaram-se, pela primeira vez, três fotoprodutos. Verificou-se um aumento da velocidade de fotodegradação do tirame na presença de substâncias húmicas. Assim, podemos concluir que a matéria orgânica, os iões cobre(II) e a luz solar têm um efeito importante no comportamento do tirame no meio ambiente. Contudo, os iões cobre têm um efeito mais marcante na degradação e persistência dos produtos que são formados.
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For the past decades it has been a worldwide concern to reduce the emission of harmful gases released during the combustion of fossil fuels. This goal has been addressed through the reduction of sulfur-containing compounds, and the replacement of fossil fuels by biofuels, such as bioethanol, produced in large scale from biomass. For this purpose, a new class of solvents, the Ionic Liquids (ILs), has been applied, aiming at developing new processes and replacing common organic solvents in the current processes. ILs can be composed by a large number of different combinations of cations and anions, which confer unique but desired properties to ILs. The ability of fine-tuning the properties of ILs to meet the requirements of a specific application range by mixing different cations and anions arises as the most relevant aspect for rendering ILs so attractive to researchers. Nonetheless, due to the huge number of possible combinations between the ions it is required the use of cheap predictive approaches for anticipating how they will act in a given situation. Molecular dynamics (MD) simulation is a statistical mechanics computational approach, based on Newton’s equations of motion, which can be used to study macroscopic systems at the atomic level, through the prediction of their properties, and other structural information. In the case of ILs, MD simulations have been extensively applied. The slow dynamics associated to ILs constitutes a challenge for their correct description that requires improvements and developments of existent force fields, as well as larger computational efforts (longer times of simulation). The present document reports studies based on MD simulations devoted to disclose the mechanisms of interaction established by ILs in systems representative of fuel and biofuels streams, and at biomass pre-treatment process. Hence, MD simulations were used to evaluate different systems composed of ILs and thiophene, benzene, water, ethanol and also glucose molecules. For the latter molecules, it was carried out a study aiming to ascertain the performance of a recently proposed force field (GROMOS 56ACARBO) to reproduce the dynamic behavior of such molecules in aqueous solution. The results here reported reveal that the interactions established by ILs are dependent on the individual characteristics of each IL. Generally, the polar character of ILs is deterministic in their propensity to interact with the other molecules. Although it is unquestionable the advantage of using MD simulations, it is necessary to recognize the need for improvements and developments of force fields, not only for a successful description of ILs, but also for other relevant compounds such as the carbohydrates.
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Bioorganic ferroelectrics and piezoelectrics are becoming increasingly important in view of their intrinsic compatibility with biological environment and biofunctionality combined with strong piezoelectric effect and switchable polarization at room temperature. Here we study piezoelectricity and ferroelectricity in the smallest amino acid glycine, representing a broad class of non-centrosymmetric amino acids. Glycine is one of the basic and important elements in biology, as it serves as a building block for proteins. Three polymorphic forms with different physical properties are possible in glycine (α, β and γ), Of special interest for various applications are non-centrosymmetric polymorphs: β-glycine and γ-glycine. The most useful β-polymorph being ferroelectric took much less attention than the other due to its instability under ambient conditions. In this work, we could grow stable microcrystals of β-glycine by the evaporation of aqueous solution on a (111)Pt/Ti/SiO2/Si substrate as a template. The effects of the solution concentration and Pt-assisted nucleation on the crystal growth and phase evolution were characterized by X-ray diffraction analysis and Raman spectroscopy. In addition, spin-coating technique was used for the fabrication of highly aligned nano-islands of β-glycine with regular orientation of the crystallographic axes relative the underlying substrate (Pt). Further we study both as-grown and tip-induced domain structures and polarization switching in the β-glycine molecular systems by Piezoresponse Force Microscopy (PFM) and compare the results with molecular modeling and computer simulations. We show that β-glycine is indeed a room-temperature ferroelectric and polarization can be switched by applying a bias to non-polar cuts via a conducting tip of atomic force microscope (AFM). Dynamics of these in-plane domains is studied as a function of applied voltage and pulse duration. The domain shape is dictated by both internal and external polarization screening mediated by defects and topographic features. Thermodynamic theory is applied to explain the domain propagation induced by the AFM tip. Our findings suggest that β-glycine is a uniaxial ferroelectric with the properties controlled by the charged domain walls which in turn can be manipulated by external bias. Besides, nonlinear optical properties of β-glycine were investigated by a second harmonic generation (SHG) method. SHG method confirmed that the 2-fold symmetry is preserved in as-grown crystals, thus reflecting the expected P21 symmetry of the β-phase. Spontaneous polarization direction is found to be parallel to the monoclinic [010] axis and directed along the crystal length. These data are confirmed by computational molecular modeling. Optical measurements revealed also relatively high values of the nonlinear optical susceptibility (50% greater than in the z-cut quartz). The potential of using stable β-glycine crystals in various applications are discussed in this work.
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Dissertação de mestrado, Aquacultura e Pescas, Faculdade de Ciências e Tecnologia, Uniersidade do Algarve, 2015
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Tese de doutoramento, Ciências do Mar ( Processos de Ecossistemas Marinhos), Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2012
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Tese de doutoramento, Informática (Engenharia Informática), Universidade de Lisboa, Faculdade de Ciências, 2015