990 resultados para fischer
Resumo:
Observational studies have reported different effects of adiposity on cardiovascular risk factors across age and sex. Since cardiovascular risk factors are enriched in obese individuals, it has not been easy to dissect the effects of adiposity from those of other risk factors. We used a Mendelian randomization approach, applying a set of 32 genetic markers to estimate the causal effect of adiposity on blood pressure, glycemic indices, circulating lipid levels, and markers of inflammation and liver disease in up to 67,553 individuals. All analyses were stratified by age (cutoff 55 years of age) and sex. The genetic score was associated with BMI in both nonstratified analysis (P = 2.8 × 10(-107)) and stratified analyses (all P < 3.3 × 10(-30)). We found evidence of a causal effect of adiposity on blood pressure, fasting levels of insulin, C-reactive protein, interleukin-6, HDL cholesterol, and triglycerides in a nonstratified analysis and in the <55-year stratum. Further, we found evidence of a smaller causal effect on total cholesterol (P for difference = 0.015) in the ≥55-year stratum than in the <55-year stratum, a finding that could be explained by biology, survival bias, or differential medication. In conclusion, this study extends previous knowledge of the effects of adiposity by providing sex- and age-specific causal estimates on cardiovascular risk factors.
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Volcanic eruptions contribute to climate variability, but quantifying these contributions has been limited by inconsistencies in the timing of atmospheric volcanic aerosol loading determined from ice cores and subsequent cooling from climate proxies such as tree rings. Here we resolve these inconsistencies and show that large eruptions in the tropics and high latitudes were primary drivers of interannual-to-decadal temperature variability in the Northern Hemisphere during the past 2,500 years. Our results are based on new records of atmospheric aerosol loading developed from high-resolution, multi-parameter measurements from an array of Greenland and Antarctic ice cores as well as distinctive age markers to constrain chronologies. Overall, cooling was proportional to the magnitude of volcanic forcing and persisted for up to ten years after some of the largest eruptive episodes. Our revised timescale more firmly implicates volcanic eruptions as catalysts in the major sixth-century pandemics, famines, and socioeconomic disruptions in Eurasia and Mesoamerica while allowing multi-millennium quantification of climate response to volcanic forcing.
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Drastic biodiversity declines have raised concerns about the deterioration of ecosystem functions and have motivated much recent research on the relationship between species diversity and ecosystem functioning. A functional trait framework has been proposed to improve the mechanistic understanding of this relationship, but this has rarely been tested for organisms other than plants. We analysed eight datasets, including five animal groups, to examine how well a trait-based approach, compared with a more traditional taxonomic approach, predicts seven ecosystem functions below- and above-ground. Trait-based indices consistently provided greater explanatory power than species richness or abundance. The frequency distributions of single or multiple traits in the community were the best predictors of ecosystem functioning. This implies that the ecosystem functions we investigated were underpinned by the combination of trait identities (i.e. single-trait indices) and trait complementarity (i.e. multi-trait indices) in the communities. Our study provides new insights into the general mechanisms that link biodiversity to ecosystem functioning in natural animal communities and suggests that the observed responses were due to the identity and dominance patterns of the trait composition rather than the number or abundance of species per se.
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PURPOSE: To assess the Medical Subject Headings (MeSH) indexing of articles that employed time-to-event analyses to report outcomes of dental treatment in patients.
MATERIALS AND METHODS: Articles published in 2008 in 50 dental journals with the highest impact factors were hand searched to identify articles reporting dental treatment outcomes over time in human subjects with time-to-event statistics (included, n = 95), without time-to-event statistics (active controls, n = 91), and all other articles (passive controls, n = 6,769). The search was systematic (kappa 0.92 for screening, 0.86 for eligibility). Outcome-, statistic- and time-related MeSH were identified, and differences in allocation between groups were analyzed with chi-square and Fischer exact statistics.
RESULTS: The most frequently allocated MeSH for included and active control articles were "dental restoration failure" (77% and 52%, respectively) and "treatment outcome" (54% and 48%, respectively). Outcome MeSH was similar between these groups (86% and 77%, respectively) and significantly greater than passive controls (10%, P < .001). Significantly more statistical MeSH were allocated to the included articles than to the active or passive controls (67%, 15%, and 1%, respectively, P < .001). Sixty-nine included articles specifically used Kaplan-Meier or life table analyses, but only 42% (n = 29) were indexed as such. Significantly more time-related MeSH were allocated to the included than the active controls (92% and 79%, respectively, P = .02), or to the passive controls (22%, P < .001).
CONCLUSIONS: MeSH allocation within MEDLINE to time-to-event dental articles was inaccurate and inconsistent. Statistical MeSH were omitted from 30% of the included articles and incorrectly allocated to 15% of active controls. Such errors adversely impact search accuracy.
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Cytokine secretion and degranulation represent key components of CD8(+) T-cell cytotoxicity. While transcriptional blockade of IFN-γ and inhibition of degranulation by TGF-β are well established, we wondered whether TGF-β could also induce immune-regulatory miRNAs in human CD8(+) T cells. We used miRNA microarrays and high-throughput sequencing in combination with qRT-PCR and found that TGF-β promotes expression of the miR-23a cluster in human CD8(+) T cells. Likewise, TGF-β up-regulated expression of the cluster in CD8(+) T cells from wild-type mice, but not in cells from mice with tissue-specific expression of a dominant-negative TGF-β type II receptor. Reporter gene assays including site mutations confirmed that miR-23a specifically targets the 3'UTR of CD107a/LAMP1 mRNA, whereas the further miRNAs expressed in this cluster-namely, miR-27a and -24-target the 3'UTR of IFN-γ mRNA. Upon modulation of the miR-23a cluster by the respective miRNA antagomirs and mimics, we observed significant changes in IFN-γ expression, but only slight effects on CD107a/LAMP1 expression. Still, overexpression of the cluster attenuated the cytotoxic activity of antigen-specific CD8(+) T cells. These functional data thus reveal that the miR-23a cluster not only is induced by TGF-β, but also exerts a suppressive effect on CD8(+) T-cell effector functions, even in the absence of TGF-β signaling.
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Background: Adiposity, as indicated by body mass index (BMI), has been associated with risk of cardiovascular diseases in epidemiological studies. We aimed to investigate if these associations are causal, using Mendelian randomization (MR) methods.
Methods: The associations of BMI with cardiovascular outcomes [coronary heart disease (CHD), heart failure and ischaemic stroke], and associations of a genetic score (32 BMI single nucleotide polymorphisms) with BMI and cardiovascular outcomes were examined in up to 22 193 individuals with 3062 incident cardiovascular events from nine prospective follow-up studies within the ENGAGE consortium. We used random-effects meta-analysis in an MR framework to provide causal estimates of the effect of adiposity on cardiovascular outcomes.
Results: There was a strong association between BMI and incident CHD (HR = 1.20 per SD-increase of BMI, 95% CI, 1.12–1.28, P = 1.9·10−7), heart failure (HR = 1.47, 95% CI, 1.35–1.60, P = 9·10−19) and ischaemic stroke (HR = 1.15, 95% CI, 1.06–1.24, P = 0.0008) in observational analyses. The genetic score was robustly associated with BMI (β = 0.030 SD-increase of BMI per additional allele, 95% CI, 0.028–0.033, P = 3·10−107). Analyses indicated a causal effect of adiposity on development of heart failure (HR = 1.93 per SD-increase of BMI, 95% CI, 1.12–3.30, P = 0.017) and ischaemic stroke (HR = 1.83, 95% CI, 1.05–3.20, P = 0.034). Additional cross-sectional analyses using both ENGAGE and CARDIoGRAMplusC4D data showed a causal effect of adiposity on CHD.
Conclusions: Using MR methods, we provide support for the hypothesis that adiposity causes CHD, heart failure and, previously not demonstrated, ischaemic stroke.
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BACKGROUND: Personalised nutrition (PN) may promote public health. PN involves dietary advice based on individual characteristics of end users and can for example be based on lifestyle, blood and/or DNA profiling. Currently, PN is not refunded by most health insurance or health care plans. Improved public health is contingent on individual consumers being willing to pay for the service.
METHODS: A survey with a representative sample from the general population was conducted in eight European countries (N= 8233). Participants reported their willingness to pay (WTP) for PN based on lifestyle information, lifestyle and blood information, and lifestyle and DNA information. WTP was elicited by contingent valuation with the price of a standard, non-PN advice used as reference.
RESULTS: About 30% of participants reported being willing to pay more for PN than for non-PN advice. They were on average prepared to pay about 150% of the reference price of a standard, non-personalised advice, with some differences related to socio-demographic factors.
CONCLUSION: There is a potential market for PN compared to non-PN advice, particularly among men on higher incomes. These findings raise questions to what extent personalized nutrition can be left to the market or should be incorporated into public health programs.
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The notion of educating the public through generic healthy eating messages has pervaded dietary health promotion efforts over the years and continues to do so through various media, despite little evidence for any enduring impact upon eating behaviour. There is growing evidence, however, that tailored interventions such as those that could be delivered online can be effective in bringing about healthy dietary behaviour change. The present paper brings together evidence from qualitative and quantitative studies that have considered the public perspective of genomics, nutrigenomics and personalised nutrition, including those conducted as part of the EU-funded Food4Me project. Such studies have consistently indicated that although the public hold positive views about nutrigenomics and personalised nutrition, they have reservations about the service providers' ability to ensure the secure handling of health data. Technological innovation has driven the concept of personalised nutrition forward and now a further technological leap is required to ensure the privacy of online service delivery systems and to protect data gathered in the process of designing personalised nutrition therapies.
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OBJECTIVE: To develop a model of the psychological factors which predict people's intention to adopt personalised nutrition. Potential determinants of adoption included perceived risk and benefit, perceived self-efficacy, internal locus of control and health commitment.
METHODS: A questionnaire, developed from exploratory study data and the existing theoretical literature, and including validated psychological scales was administered to N=9381 participants from 9 European countries (Germany, Greece, Ireland, Poland, Portugal, Spain, the Netherlands, the UK, and Norway).
RESULTS: Structural equation modelling indicated that the greater participants' perceived benefits to be associated with personalised nutrition, the more positive their attitudes were towards personalised nutrition, and the greater their intention to adopt it. Higher levels of nutrition self-efficacy were related to more positive attitudes towards, and a greater expressed intention to adopt, personalised nutrition. Other constructs positively impacting attitudes towards personalised nutrition included more positive perceptions of the efficacy of regulatory control to protect consumers (e.g. in relation to personal data protection), higher self-reported internal health locus of control, and health commitment. Although higher perceived risk had a negative relationship with attitude and an inverse relationship with perceived benefit, its effects on attitude and intention to adopt personalised nutrition was less influential than perceived benefit. The model was stable across the different European countries, suggesting that psychological factors determining adoption of personalised nutrition have generic applicability across different European countries.
CONCLUSION: The results suggest that transparent provision of information about potential benefits, and protection of consumers' personal data is important for adoption, delivery of public health benefits, and commercialisation of personalised nutrition.
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No âmbito do Mestrado em Química, com especialização em Química Orgânica e Produtos Naturais, será apresentado nesta dissertação o trabalho desenvolvido sobre a síntese e caracterização de fosfatos e fosfonatos metálicos tetravalentes, assim como a avaliação da sua capacidade catalítica em reações de esterificação. Iniciou-se este trabalho pela síntese de vários fosfatos e fosfonatos metálicos tetravalentes, que apresentam a fórmula geral MIV(HXO4)2.nH2O e MIV(RXO3)2.nH2O, respetivamente, onde MIV = Zr, X = P, W, Mo e R = grupo orgânico. Os compostos sintetizados foram caracterizados por espetroscopia de infravermelho, difração de raios-X de pós e por análise elementar e termogravimétrica. Os fosfatos e fosfonatos metálicos tetravalentes foram avaliados como catalisadores em reações de esterificação de Fischer entre os ácidos acético, ou benzóico, e diferentes álcoois. Após esta avaliação foram efetuados estudos de otimização das condições reacionais para a síntese de cada éster. Em cada um dos casos foi utilizado o catalisador com o qual se obtiveram os melhores rendimentos nos estudos iniciais, ou seja com o molibdato-fenilfosfonato de zircónio(IV), ZrMoPhP. Todas as reações foram monitorizadas por cromatografia gasosa ou por cromatografia líquida de alta pressão. Todos os ésteres foram identificados por comparação com os padrões correspondentes.
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Background The practice of reading and discussing literature in groups is long established, stretching back into classical antiquity (Fischer, 2004). While benefits of therapeutic reading groups have been highlighted, research into participants’ perceptions of these groups has been limited (Walwyn & Rowley, 2011). Aims To explore the experiences of those attending therapeutic reading groups, considering the role of both the group, and the literature itself, in participants’ ongoing experiences of distress. Method Eleven participants were recruited from two reading groups in the South East of England. One focus group was run, and eight individuals self selected for individual interviews. The data were analysed together using a thematic analysis drawing on dialogical theories. Results Participants described the group as an anchor, which enabled them to use fiction to facilitate the discussion of difficult emotional topics, without referring directly to personal experience. Two aspects of this process are explored in detail: the use of narratives as transportation, helping to mitigate the intensity of distress; and using fiction to explore possibilities, alternative selves and lives. Conclusions For those who are interested and able, reading groups offer a relatively de-stigmatised route to exploring and mediating experiences of distress. Implications in the present UK funding environment are discussed.
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A syntactical brightness model based on a multiscale line and edge representation obtained by a set of anisotropic Gabor filters is quite complex (du Buf and Fischer, 1995 Optical Engineering 34 1900-1911). Although only tested in 1-D, it was shown to yield correct brightness effects for many patterns.
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Theories of embodied cognition argue that language processing arises not from amodal symbols that redescribe sensorimotor and affective experiences, but from partial simulations (reenactments) of modality-specific states. Recent findings on processing of words and sentences support such a stance emphasizing that the role of the body in the domain of language comprehension should not be overlooked or dismissed. The present research was conducted to extend prior work in two important ways. First, the role of simulation was tested with connected discourse rather than words or sentences presented in isolation. Second, both “online” and “offline” measures of discourse comprehension were taken. In Experiments 1 and 2 participants’ facial postures were manipulated to show that preparing the body for processing of emotion-congruent information improves discourse comprehension. In Experiment 3 the direction of body posture was manipulated to show that implicit properties of simulations, such as spatial dimension or location, are at least somewhat involved in processing of large language segments such as discourse. Finally, in Experiments 4 and 5 participants’ body movement and body posture were manipulated to show that even understanding of language describing metaphorical actions physically impossible to perform involves constructing a sensorimotor simulation of the described event. The major result was that compatibility between embodiment and language strongly modulated performance effectiveness in experiments on simulation of emotion and metaphorical action. The effect of simulation on comprehension of discourse implying spatial dimension was fragile. These findings support an embodied simulation account of cognition suggesting that sensorimotor and affective states are at least partially implicated in “online” and “offline” discourse comprehension.
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In einem Artikel der Zeitschrift Die Zeit wird die Generation Y, die Generation deren Angehörige derzeit zum Großteil ihre akademische Ausbildung beenden und sich dem Arbeitsmarkt zuwenden, auch als Generation Pippi, angelehnt an Astrid Lindgrens Kinderbuchheldin Pippi Langstrumpf, bezeichnet (Bund et al., 2013: 1). Individualität, eine ausgeprägte Abneigung gegenüber Autoritätspersonen, der Wunsch nach Spaß und Abwechslung sowie das Bestreben, sich selbst zu verwirklichen, charakterisieren Pippi Langstrumpf (Bund et al., 2013: 1). Diese Charakterbeschreibungen werden z. T. auf die Generation Y übertragen und stellen Unternehmen vor eine Herausforderung: Um Arbeitnehmer der Generation Y affektiv zu binden, so dass sich in diese getätigte und noch zu tätigenden Investitionen rentieren, müssen neue Strategien entwickelt werden. Innerhalb dieser Bachelorarbeit konnten erste Erkenntnisse dahingehend gewonnen werden, dass u. a. Work-Life-Balance Maßnahmen, (gesundheitsorientierte) Führung, ein positives Arbeitsklima und Mitbestimmung als Auslöser affektiven organisationalen Commitments der Generation Y fungieren können. Bei der nachfolgend dargestellten Arbeit handelt es sich um eine überarbeitete Version der gleichnamigen Bachelorarbeit, die von Prof. Dr. Sven Litzcke sowie von Prof. Dr. Dr. Daniel Wichelhaus betreut wurde.
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In this paper I outline possibilities for, and issues arising from, opposition towards the dominant ideologies and practices of marketing knowledge (Hirschman 1993) through an engagement with feminist epistemology (Longino 1991, Harding 1987). Feminist epistemology is a political branch of naturalised epistemology (Quine 1969) primarily concerned with critique of constructions of gender, gender norms and gendered interests within the production of knowledge (Anderson 1995) and with theorising, grounding and legitimating feminist knowledge making practices (Harding 1987). It is most often associated with the feminist critique of science, and with feminist science and technology studies (Haraway 1987, Wajman 1997). Feminist epistemology asks the question, ‘what is the nature of the feminist critical project as a way of knowing?’ (McLennan 1995:392). This paper outlines the basis of the feminist critique of knowledge generally, and as applied to marketing knowledge, offers description of the three main epistemological approaches to this question and suggestions for their application in practice. The paper progresses important work by consumer behaviour theorists (Bristor and Fischer 1993, Hirschman 1993) on the potentials of feminist ways of knowing for marketing and consumer behaviour by moving beyond the tripartite of feminist approaches outlined, and extending the discussion to take into account the development of situated knowledges theory (Haraway 1989, 1997), which has become so important in the decade since these papers were written. It joins ongoing conversations in consumer behaviour and marketing that share similar feminist concerns (Catterall et al 1997, 2000, 2005, Bettany and Woodruffe Burton 1999, 2005, and Hogg et al 1999, 2000) but in this contribution it takes a slightly tangential approach, seeing marketing knowledge in terms of its epistemic culture by using a model of masculinity in academic cultures from feminist theory (Wagner 1994) to help conceptualise it as such. The dominant masculine ideology of marketing knowledge both in execution (Penaloza 1994, Bristor and Fischer 1994, Fischer and Bristor 1993, Woodruffe 1996), and values (Hirschman 1993, Brown 2000, Desmond 1997) has been well documented over the past fifteen years. However, although the basis of this, how is it manifested and how a feminist informed marketing knowledge could be achieved, have been addressed somewhat in the literature (Bristor and Fischer 1993, Hogg, Bettany and Long 2000) an updated rendering is necessary which focuses specifically on epistemology and situates this discussion within a cultural framework. To do this I use the notions of cultural masculinity in academic disciplines developed by Wagner (1994) of ‘organisational egocentrism’, ‘fake collectivity’ and ‘de realisation’. With these, I raise important and specific issues around the notion of the masculinity of marketing knowledge, and then present an outline of feminist epistemologies to illustrate how different feminist approaches to knowledge would address these concerns.