651 research outputs found

    HAGR: the Human Ageing Genomic Resources

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    The Human Ageing Genomic Resources (HAGR) is a collection of online resources for studying the biology of human ageing. HAGR features two main databases: GenAge and AnAge. GenAge is a curated database of genes related to human ageing. Entries were primarily selected based on genetic perturbations in animal models and human diseases as well as an extensive literature review. Each entry includes a variety of automated and manually curated information, including, where available, protein–protein interactions, the relevant literature, and a description of the gene and how it relates to human ageing. The goal of GenAge is to provide the most complete and comprehensive database of genes related to human ageing on the Internet as well as render an overview of the genetics of human ageing. AnAge is an integrative database describing the ageing process in several organisms and featuring, if available, maximum life span, taxonomy, developmental schedules and metabolic rate, making AnAge a unique resource for the comparative biology of ageing. Associated with the databases are data-mining tools and software designed to investigate the role of genes and proteins in the human ageing process as well as analyse ageing across different taxa. HAGR is freely available to the academic community at http://genomics.senescence.info

    Electrokinetic remediation of PPCPs in soil: influence of soil biota and environmental factors

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    The use of treated wastewater for agricultural irrigation, is a common practice in several countries as it has several benefits, such as decreasing pressure on freshwater sources and reduced nutrient loads to receiving waters. However, wastewater treatment plants (WWTP) are not always able to remove all the contaminants present, thus representing a significant risk for environmental contamination. Soil contamination by wastewater may potentially promote contaminants uptake and accumulation by plants and derived products which consequently can affect human health. Pathogens and heavy metals are traditionally the main concern, however contaminants of emerging concern (CECs), and particularly pharmaceutical and personal care products (PPCPs), are gaining scientific and public attention. In the present dissertation, the electrokinetic (EK) process was applied as a remediation technology to an agricultural soil contaminated with a mixture of PPCPs. To better understand the remediation mechanisms involved, different assays were developed to discriminate biotic, abiotic and EK contributions, alone and coupled, to the degradation of the PPCPs. As environmental factors may affect the remediation processes, trials with and without irrigation and at different temperatures were also conducted (18 and 24 ºC). As contaminants, 10 commonly environmentally occurring PPCPs were selected for the study: 17β-estradiol (E2), sulfamethoxazole (SMX), bisphenol A (BPA), ibuprofen (IBU), 17α-ethinylestradiol (EE2), oxybenzone (OXY), triclosan (TCS), diclofenac (DCF), caffeine (CAF) and carbamazepine (CBZ). These compounds represent the major PPCPs classes and attain diverse physicochemical properties. All experiments were carried out in a lab scale microcosm using a 12h ON/OFF current mode at 20 mA for 4 days (in duplicates). The best remediation results were attained when EK process was applied in biotic conditions at 24ºC and combined with a daily irrigation (EK-Biotic-24-W); these conditions allowed to remove approximately 37% of the total mass on PPCPs in the soil. By eliminating the microbiological contribution to the degradation processes (sterilized soil; abiotic setting) in the same EK conditions (EK-Abiotic-24-W) a decrease in the removal by 7% was observed. The abiotic removal mechanisms only contributed to a total mass decay of 6%, whereas the biotic mechanism removed 20% (at 24ºC). The PPCPs more recalcitrant to degradation were CBZ, OXY and TCS. Oppositely E2, SMX e BPA displayed to be more biodegradable. Such results are compatible with previous tests, which suggest that usage of EK in combination with bioremediation vastly improves the efficiency over that of EK remediation alone in removing pollutants from soil. The EK process showed to be an effective option for the remediation of PPCPs in clay soils, which may enhance the degradation of contaminants by two main remediation mechanisms: (i) electrochemical induced degradation and (ii) bioremediation

    Cross sectional and prospective relationship between physical activity and depression in Europe older adults

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    Objectives: The present study aims to analyse the cross-sectional and prospective relationship between regular practice of moderate and vigorous physical activity (PA) and depression symptoms using data from 2011 and 2013. Methodology: This study analysed 38135 European older adults, from 13 European countries across a two-year follow-up. Data was collected in the fourth (in 2011) and fifth (in 2013) wave, from the Survey of Health, Ageing and Retirement in Europe (SHARE). For the present analysis were only considered participants who responded to the EURO-D 12-item scale of symptoms of depression, and with reported PA. Participants were inquired about the presence or absence of twelve symptom domains of depression and asked to report their frequency of moderate PA and vigorous PA. General linear models were conducted to access the cross-sectional and prospective associations. Results: For both men and women, practising moderate or vigorous PA in 2011 was associated with a lower score of depression in 2011 and 2013. From the prospective analysis, moderate and vigorous PA in 2011 was inversely associated with the score of depression. This association remains significant in the fully adjusted model. Conclusions: Moderate and vigorous PA practised once, or more than once a week is negatively related to the score of depression, both in men and women. The present study brings further support to the notion that PA is negatively associated with depression symptoms

    Cycles in Politics: Wavelet Analysis of Political Time-Series

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    Spectral analysis and ARMA models have been the most common weapons of choice for the detection of cycles in political time-series. Controversies about cycles, however, tend to revolve about an issue that both techniques are badly equipped to address: the possibility of irregular cycles without fixed periodicity throughout the entire time-series. This has led to two main consequences. On the one hand, proponents of cyclical theories have often dismissed established statistical techniques. On the other hand, proponents of established techniques have dismissed the possibility of cycles without fixed periodicity. Wavelets allow the detection of transient and coexisting cycles and structural breaks in periodicity. In this paper, we present the tools of wavelet analysis and apply them to the study to two lingering puzzles in the political science literature: the existence to cycles in election returns in the United States and in the severity of major power wars.

    Synchronism in Electoral Cycles: How United are the United States?

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    The role of national, sectional, state, and local forces in driving electoral outcomes in the United States has remained a matter of considerable indeterminacy in the American politics literature. In what concerns House elections, different approaches and methods have yielded widely divergent results. In what concerns presidential elections, considerable doubts remain about the timing and the plausible causes of a long-term trend towards homogeneity. In this paper, we take a new look at the nationalization of politics in the United States. We are particularly interested in the dynamic nationalization in presidential elections, i.e., the extent to which swings and shifts from one election to the next have been similar across states and whether or not that similarity has increased through time. We treat this problem as one of similarity or dissimilarity — and convergence or divergence of — electoral cycles, and use wavelets analysis in order to ascertain the degree to which the national and state election cycles have been synchronized and the degree to which that synchronization has increased or decreased. We determine, first, the states where electoral change has been more in sync with the national cycle and clusters of states defined in terms of the mutual synchronization of their own electoral cycles. Second, we analyze how the degree of synchronization of electoral cycles in the states has changed through time, answering questions as to when, to what extent, and where has the tendency towards a “universality of political trends” in presidential elections been more strongly felt. We present evidence strongly in favor of an increase in the dynamic nationalization of presidential elections taking place in the 1950s, showing that alternative interpretations concerning the historical turning point in this respect are not supported by empirical evidence.

    Efeito do grau de superenrolamento de plasmídeos na sua estabilidade estrutural e função biológica

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    Tese de mestrado em Biologia (Biologia Molecular e Genética), apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2008Actualmente, a utilização de DNA plasmídico (pDNA) como vector em Terapia génica, e em particular nas vacinas de DNA tem vindo a generalizar-se. Estas moléculas podem existir em diferentes conformações com diversos graus de superenrolamento. Várias evidências apontam para uma relação entre este superenrolamento e o sucesso das vacinas de DNA. O objectivo principal deste trabalho foi estudar o efeito do grau de superenrolamento na estabilidade estrutural e função biológica de plasmídeos destinados a terapia génica. Utilizaram-se seis plasmídeos todos derivados do vector comercial pVAX1/LacZ, três dos quais (pVAX1/GFP-BGH, pVAX1/GFP-SV40, pVAX1/GFP-Synt) contêm o gene que codifica a proteína repórter GFP (Green Fluorescent Protein) e os outros três (pVAX1/LacZ-BGH, pVAX1/LacZ-SV40, pVAX1/LacZ-Synt), o gene que codifica a proteína repórter ß-galactosidase. Dentro de cada grupo de três plasmídeos, as diferenças situam-se a nível das sequências de poliadenilação. A utilização de técnicas baseadas na electroforese em géis de agarose das séries completas de topoisómeros, permitiram a determinação do grau de superenrolamento dos plasmídeos utilizados como modelos de estudo. A análise estrutural dos mesmos, por electroforese bidimensional e espectroscopia de dicroísmo circular, não detectou qualquer transição estrutural ou conformação alterada. Estudou-se também a influência do superenrolamento na resistência dos plasmídeos à acção da nuclease S1 e verificou-se que os plasmídeos mais superenrolados são menos resistentes. Por fim, investigou-se o efeito do grau de superenrolamento na função biológica dos vectores plasmídicos e verificou-se que a isoforma superenrolada apresenta sempre percentagens de transfecção superiores à correspondente forma relaxada.The past decade has seen the use of plasmid DNA as a vector for gene therapy, in particular DNA Vaccines, broaden up. These therapeutic molecules may exist in several different conformations, and also in different degrees of supercoiling. Evidences show that there is a relation between the supercoiling and the vaccine's success. The scope of this research was to study the effect of different degrees of supercoiling in the structural stability and biological function of plasmid DNA, to be used in gene therapy. In order to do so, six model plasmids derived from the commercial pVax1/LacZ were used. Three of these plasmids (pVAX1/GFP-BGH, pVAX1/GFP-SV40, pVAX1/GFP-Synt) contained the reporter gene GFP (Green Fluorescent Protein) whereas, the other three (pVAX1/LacZ-BGH, pVAX1/LacZ-SV40, pVAX1/LacZ-Synt), contained the reporter gene ß-galactosidase. Within each group of the referred plasmids the differences lie specifically in the polyadenilation sequences. The use of tecniques based in agarose electrophoresis gels of all the series of topoisomers allowed to determine the degree of supercoiling of each of the plasmids used as a study model. Further structure analysis of the model plasmids by bidimensional electrophoresis and by circular dichroism has not detected any structural transition nor conformation change. The influence of supercoiling in the resistance to nucleases action was also studied, proving that the most supercoiled plasmids are more prone to the action of the S1 nuclease. Finally, the effect of the degree of supercoiling in the biological function of the DNA vaccines was also studied. The latter showed that the supercoiled isoforms of the model plasmids always presented higher transfection percentages than their corresponding relaxed isoform

    Factors influencing electric vehicles adoption : do gender and experience matter? : a Portuguese overview

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    Nowadays, enterprises are working towards promoting sustainability in their businesses, due to the on-going trends, and the fact that the market is demanding it. Meanwhile, consumers are becoming more responsible and practicing sustainable actions, increasing consciousness, and having a crucial role in the society, in order to reduce the carbon footprint, reduce unnecessary wastes and avoid harming the environment. Electric vehicles are seen as highly sustainable, due to the non-emissions of carbon to the atmosphere. Though, their production is unsustainable, as it is the case of the batteries. Therefore, the aim of this study is to explore the reasons behind consumers intention to purchase electric vehicles. Due to its growth over the past years, this is a topic that has been widely explored. As so, it gains importance of which are the determinant factors that are perceived by consumers in their decision-making and if it differs from Gender or Experience. The methodology used was quantitative and information was gathered through an online questionnaire to people that live in Portugal. The results revealed that the characteristic that was considered the most relevant to influence the intention to purchase was the fact that these vehicles are environmentally friendly. Yet, higher purchase price was found as being the prime Barrier to this acquaintance. Moreover, some respondents mentioned the fact that electric vehicles are not as green as they are portrayed. Regarding Gender and Experience, just the Incentive factors to the purchase had relations with these variables.Atualmente, as empresas estão a trabalhar de forma a promover a sustentabilidade nos seus negócios, devido às tendências atuais e, ao facto de o mercado o exigir. Os consumidores estão se a tornar cada vez mais responsáveis e a praticar ações sustentáveis, aumentando a consciencialização, e a desempenhar um papel crucial na sociedade, de forma a reduzir a pegada de carbono, reduzir gastos desnecessários e evitar prejudicar o ambiente. Os veículos elétricos são vistos como altamente sustentáveis, por não emitirem carbono para a atmosfera. No entanto, a sua produção é pouco sustentável, como é o caso das baterias. Assim sendo, o objetivo deste estudo é explorar quais as razões por detrás da intenção de compra dos consumidores em relação a veículos elétricos. Devido ao seu crescimento nos últimos anos, este é um tema que tem estado a ser bastante explorado. Portanto, o tópico ganha importância na perspetiva de perceber quais são os fatores de Incentivo ou as Barreiras que os consumidores consideram determinantes na sua decisão de compra e se os mesmos diferem de acordo com o Género ou Experiência. A metodologia utilizada foi quantitativa e foi recolhida informação através de um inquérito online a pessoas residentes em Portugal. Os resultados revelam que a característica mais relevante que influencia a intenção de compra é o facto destes veículos serem amigos do ambiente. Por outro lado, preço de compra elevado revelou ser a principal barreira à aquisição destes veículos. Além disso, alguns inquiridos mencionaram o facto de os veículos elétricos não serem tão verdes como são retratados. No que toca ao Género e à Experiência, apenas os fatores de Incentivo à compra estabeleceram relação com estas variáveis
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