Suchergebnisse

A contaminação de alimentos por aflatoxinas, principalmente, a aflatoxina B1 (AFB1) representa um problema mundial para a saúde humana e animal. Uma forma de avaliar a exposição a estes contaminantes é analisando a dieta para verificar a ocorrência destes compostos. Esta metodologia, no entanto, tem limitações devido à variabilidade das aflatoxinas encontradas nos alimentos e às diferenças individuais na toxicocinética dos compostos. Por outro lado, o biomonitoramento de aflatoxinas em fluidos biológicos se utilizando de biomarcadores gera informações mais confiáveis sobre a exposição a estas toxinas nos indivíduos. O uso de adsorventes químicos na ração animal possibilita a detoxificação de aflatoxinas sem produzir efeitos tóxicos nem alterar as propriedades nutricionais. Este trabalho teve por objetivo revisar os dados publicados sobre a eficiência in vitro e in vivo de adsorventes para aflatoxinas, bem como estudos referentes ao uso da aflatoxina M1 (AFM1) e da AFB1-lisina como biomarcadores para avaliar a redução da biodisponibilidade da AFB1 por adsorventes em rações. Trabalhos relevantes publicados nos últimos dez anos (2009-presente) foram selecionados nas bases de dados PubMed, Science Direct e Google Scholar. A determinação de AFM1 no leite e/ou na urina, bem como de AFB1-lisina no soro, indica a biodisponibilidade individual da AFB1 em ensaios para avaliar a eficiência de adsorventes em animais. Deste modo, a utilização destes biomarcadores permite reduzir os custos dos ensaios in vivo, além de proporcionar maior padronização dos experimentos e possibilitar a avaliação da eficiência dos adsorventes em condições de campo. Palavras chave: AFB1. - Adsorventes Minerais. Biomarcadores de Exposição - AFB1-lisina - AFM1 AbstractFood contamination by aflatoxins, mainly aflatoxin B1 (AFB1), is a worldwide concern for human and animal health. A possible way to assess the exposure to these contaminants is through the diet analyses to verify the occurrence of mycotoxins. However, this methodology has important limitations due to the variability of mycotoxins found in the food and the individual differences in the toxicokinetics of the compounds. On the other hand, biomonitoring of aflatoxins in biological fluids using biomarkers generates more reliable information on the exposure to these toxins in individuals. The use of chemical adsorbents in animal feed makes it possible to detoxify mycotoxins without producing toxic effects or altering the nutritional properties. The aim of this study was to revise the available published data on the in vitro and in vivo efficacy of adsorbents for aflatoxins, as well as studies on the use of aflatoxin M1 (AFM1) and AFB1-lysine as biomarkers to evaluate the reduction in the bioavailability of AFB1 by adsorbents in feed. Relevant articles published in the last 10 years (2009-present) were selected in PubMed, Science Direct and Google Scholar. Determination of AFM1 in milk and/or urine, and AFB1-lysine in serum, indicate the individual bioavailability of AFB1 in trials conducted for evaluation of adsorbent's efficiency in animals. Thus, the use of these biomarkers may reduce the costs of in vivo trials, increase the standardization of experiments, and evaluate the adsorbents' efficiency under field conditions. Keywords: Aflatoxin B1 – Clays - Exposure Biomarkers - Aflatoxin B1-lysine Aflatoxin M1.

In this paper we study the effect of institutional reform on the decision to hold risky assets at the extensive and the intensive margin. We therefore make use of the natural experiment of German Division and Reunification and, based on savings bank customer data from German savings banks, study whether the customers of East German banks differ from their West German counterparts. While we find only slight differences in the decision to hold risky assets at the extensive margin, the differences turn out to be much larger at the intensive margin. Moreover, the latter effects turn out to be quite persistent even in the age group of individuals which were too young at the time of German Reunification to have collected financial experiences in one of the previously existing systems. Our results support the view that reforms allowing individuals to get easy access to financial markets quite quickly result in increasing market participation. However, the degree and sort of risk, individuals are willing to bear, seems to change only slowly as the portfolios of East and West German savings bank customers still differ considerably 15 years after German Reunification. We attribute this finding to the only slowly changing informal institutions.

Abstract: Background: Suicidal ideation (SI) and suicide attempts (SA) are common in autistic individuals, but prevalence rates have not yet been estimated with meta-analysis. Aims: This meta-analysis aims to estimate SI and SA prevalence rates in autistic individuals and identify subgroup differences based on sample characteristics and study quality. Methods: A systematic search identified 52 studies with 88,509 autistic participants reporting SI and SA. Pooled prevalence estimates were calculated using a random-effects model. Results: Pooled prevalence estimates of lifetime SI and SA were 37.2% [95% CI 25.3–50.8] and 15.3% [95% CI 9.5–23.6], respectively. For 12-month prevalence, this was 25.4% [95% CI 19.0–33.2] and 14.1% [95% CI 7.4–25.2], respectively. Subgroup analyses revealed significant differences based on age (SI), region (SI), data collection (SI), measurement scales used to define autism and suicidality (SA), and representation of the study sample (SI and SA). Heterogeneity measures were high for all outcomes ( I2 = 60.3–99.1%). Limitations: The heterogeneity of the included studies may limit the generalizability of our findings. Conclusion: The high rates of suicidal problems in autistic individuals call for a systematic evaluation of suicidality in clinical practice and adequate therapeutic interventions to improve this condition.

Abstract: Background: Previous studies have demonstrated that excluding individuals at risk of suicide from online depression interventions can impact recruited sample characteristics. Aim: To determine if a small change in suicide risk exclusion criterion led to differences in the usage and effectiveness of an Internet depression intervention at 6 months of follow-up. Method: A partial sample of a recently completed online depression intervention trial was divided into two groups: those with no risk of suicide versus those with some risk. The two groups were compared for baseline demographic and clinical measures, as well as intervention uptake and treatment success across 6 months. Results: Overall, individuals with less risk of suicide at baseline reported significantly less severe clinical symptoms. Both groups interacted with the intervention at the same rate, but specific use of modules was different. Finally, the impact of intervention usage on outcomes over time did not vary by group. Limitations: While different suicide risk exclusion criteria can change recruited sample characteristics, it remains unclear how these differences impact intervention uptake and success. Conclusion: Overall, the findings suggest that researchers should exercise caution when excluding individuals at risk of suicide, as they greatly benefit from web-based interventions.

In the past decades, the United States had welcomed a large number of foreign-born individuals into its society. At the same time, there is a question of whether the inflow of immigrants affects the educational attainment of U.S. natives. To shed light on the issue, this article examines an episode in American history when approximately 125,000 Cuban refugees entered Florida in the short six-month period between April and September of 1980, later known as the Mariel Boatlift. The results from difference-in-differences analysis show a temporary decline (1.6 pp.) in school enrollment among non-Hispanic white individuals following Mariel Boatlift. This temporary decline is mainly driven by a decrease in college enrollment. Examining how the affected cohorts fared after they have completed their education, about 30 years after the event, the results show that Mariel Boatlift does not have an economically meaningful impact on their educational attainment, suggesting that many individuals leaving schools in the short period after the event re-enroll in the subsequent years. This finding is consistent with recent studies that found that the inflow of Cuban refugees improved the labor market conditions of less-skilled workers in the short period after Mariel Boatlift, increasing the opportunity costs of pursuing higher education.

Policy analytics combines new data sources, such as from mobile smartphones, Internet of Everything devices, and electronic payment cards, with new data analytics techniques for informing and directing public policy. However, those who do not own these devices may be rendered digitally invisible if data from their daily actions are not captured. We explore the digitally invisible through an exploratory study of homeless individuals in Phoenix, Arizona, in the context of extreme heat exposure. Ten homeless research participants carried a temperature‐sensing device during an extreme heat week, with their individually experienced temperatures (IETs) compared to outdoor ambient temperatures. A nonhomeless, digitally connected sample of 10 university students was also observed, with their IETs analyzed in the same way. Surveys of participants complement the temperature measures. We found that homeless individuals and university students interact differently with the physical environment, experiencing substantial differences in individual temperatures relative to outdoor conditions, potentially leading to differentiated health risks and outcomes. They also interact differently with technology, with the homeless having fewer opportunities to benefit from digital services and lower likelihood to generate digital data that might influence policy analytics. Failing to account for these differences may result in biased policy analytics and misdirected policy interventions.

Many governments world-wide are promoting longer working life due to the social and economic repercussions of demographic change. However, not all workers are equally able to extend their employment careers. Thus, while national policies raise the overall level of labour market participation, they might create new social and labour market inequalities. This paper explores how institutional differences in the United Kingdom, Germany and Japan affect individual retirement decisions on the aggregate level, and variations in individuals' degree of choice within and across countries. We investigate which groups of workers are disproportionately at risk of being 'pushed' out of employment, and how such inequalities have changed over time. We use comparable national longitudinal survey datasets focusing on the older population in England, Germany and Japan. Results point to cross-national differences in retirement transitions. Retirement transitions in Germany have occurred at an earlier age than in England and Japan. In Japan, the incidence of involuntary retirement is the lowest, reflecting an institutional context prescribing that employers provide employment until pension age, while Germany and England display substantial proportions of involuntary exits triggered by organisational-level redundancies, persistent early retirement plans or individual ill-health.

This study aims to uncover how horizontal inequality affects support for violent and nonviolent resistance among Palestinians in the West Bank and Gaza. National survey data are introduced to operationalize the mechanisms proposed in the horizontal inequality literature on the individual level. Results point to the operation of political and economic horizontal inequality mechanisms in the Palestinian case. Higher perceived status of civil and political rights is associated with a lower probability of supporting violent over nonviolent resistance. Individuals are also more likely to support violent over nonviolent resistance the larger the difference in household expenditure and consumer durable ownership between their own region and the closest Israeli subdistrict. Corresponding differences in educational attainment have no corresponding effect. The results demonstrate how economic and political horizontal inequality can increase the risk that an individual becomes part of the mobilizational potential of violent social movements. This can lead to participation in a wide range of supportive actions that increase the viability of such movements, ranging from material support to direct participation in violence. The level of public support for violent resistance in key constituencies could also influence public opinion sensitive actors like Hamas in their choice between violent and nonviolent resistance strategies.

Although organizational theorists have long argued that environments shape organizational structures, they have paid little attention to the processes by which the shaping occurs. This paper examines these processes by showing how environments shape teaching and learning activities, which in turn shape structure. Observational field data from structural engineering groups in three firms and hardware engineering groups in three firms revealed that the two occupations exhibited different patterns of learning episodes and different distributions of actors across those episodes, or what, following the work of Roger Barker, we call two distinct teaching-learning ecologies. After detailing the differences in the two ecologies, we show how these differences emerged from patterns of behavior that were influenced by unique sets of environmental and technological constraints. By demonstrating how actions transform environmental constraints into organizational structure, this paper indicates how research on individual learning in organizations can speak to larger concerns in organizational theory. Moreover, by adopting a synthetic and pragmatic approach to individual learning as a social activity, the paper highlights the role of teachers in workplace learning and casts doubts on the existence of a universal model of how individuals learn at work.

This paper investigates the short-term effects of public smoking bans on individual smoking behavior. In 2007 and 2008, state-level smoking bans were gradually introduced in all of Germany's federal states. We exploit this variation to identify the effect that smoke-free policies had on individuals' smoking propensity and smoking intensity. Using rich longitudinal data from the German Socio-Economic Panel Study, our difference-in-differences estimates show that the introduction of smoke-free legislation in Germany did not change average smoking behavior within the population. However, our estimates point to important heterogeneous effects. Individuals who go out more often to bars and restaurants did adjust their smoking behavior. Following the ban, they became less likely to smoke and also smoked less. ; NOTICE: This is the author's version of a work that was accepted for publication in Journal of Health Economics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Health Economics 30 (2011), 3, pp. 591-601 and is online available at http://dx.doi.org/10.1016/j.jhealeco.2011.03.003.

The Canary Islands (one of Spain's 17 autonomous communities) is considered in the EC Treaty "ultra-peripheral region" which means: i) differences in the development processes and integration that justify certain specific policies (six out of the seven regions involved are among the poorest in the EU). This is related with remoteness, insularity, small size, difficult topography and climate, and the dependence on a small number of products; ii) the remoteness from the mainland countries and climatic conditions (tropical or subtropical) and, iii) the role of EU frontier and the geographical structure characterized by size and distance. With data of the Survey of Social Conditions (2001) we study the income inequality of individuals in The Canary Islands. Individuals are divided into various subgroups along several dimensions, such as island of residence, age, employment status etc. The difference in inequality between and within the various subgroups is studied using absolute-relative poverty line. We estimate poverty using a subjective approach too, where the level of the poverty line is derived using the opinion of the individual, rich or poor, on poverty. The subjective poverty line used is the Leyden Poverty Line based on subjective questions regarding income and economic welfare.

In this article we present new results of a novel computational approach to the interaction of two important cognitive‐linguistic phenomena: (1) language learning; and (2) language change over time (diachronic linguistics). We exploit the insight that while language learning takes place at the individual level, language change is more properly regarded as an ensemble property that takes place at the level of populations of language learners. We show by analytical and computer simulation methods that language learning can be regarded as the driving force behind a dynamical systems account of language change. We apply this model to the specific case of historical change from Classical Portuguese to European Portuguese, demonstrating how a particular language learning model coupled with data on the differences between Classical and European Portuguese leads to specific predictions for possible language‐change envelopes. The main investigative message of this paper is to show how this methodology can be applied to a specific case, that of Portuguese. The main moral underscores the individual/population difference; we show that simply because an individual will choose a particular grammar does not mean that all other grammars will be eliminated.

ABSTRACTThis article takes issue with the rational choice approach that views the economy as an autonomous realm where isolated individuals make maximizing choices in terms of their personal preferences. The argument made is that income generation, consumption and exchange form a holistic complex that must be studied in its unity and that the economy and individual economic behaviour are articulated with a social context. This is demonstrated by evidence (collected through fieldwork) on the differences in the use of remittances by three villages in Kerala, India, which have experienced large scale migration to the Middle Eastern countries.In the three cases, it was the way in which income earned from international migration was perceived, together with the variation in ethnic structures, that explained the similarities and differences in their consumption, exchange and investment patterns. In each case, it was the larger ethnic structure that conditioned (1) the types of activities into which the money was channelled; (2) the range of people who were the beneficiaries of migrant remittances; (3) the patterns of reciprocity or charity practised by the migrants; (4) the selection of the trade‐off point between community status and economic accumulation; and; (5) the groups of individuals who gained or lost economic control.