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Nanomaterials are increasingly being added to food handling and packaging materials, or directly, to human food and animal feed. To ensure the safety of such engineered nanomaterials (ENMs), in May 2011, the European Food Safety Authority (EFSA) published a guidance document on Risk assessment of the application of nanoscience and nanotechnologies in the food and feed chain. It states that risk assessment should be performed by following a step-wise procedure. Whenever human or animal exposure to nanomaterials is expected, the general hazard characterisation scheme requests information from in vitro genotoxicity, toxicokinetic and repeated dose 90-day oral toxicity studies in rodents. Numerous prevailing uncertainties with regard to nanomaterial characterisation and their hazard and risk assessment are addressed in the guidance document. This article discusses the impact of these knowledge gaps on meeting the goal of ensuring human safety. The EFSA's guidance on the risk assessment of ENMs in food and animal feed is taken as an example for discussion, from the point of view of animal welfare, on what level of uncertainty should be considered acceptable for human safety assessment of products with non-medical applications, and whether animal testing should be considered ethically acceptable for such products.  相似文献   

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A fundamental lack of data on the potential impacts of carbon based nanomaterials on natural ecosystems currently exists. The gap between what we know about environmental impacts and new products that may contain nanomaterials continues to get wider especially related to knowledge about nanocomposites. In this paper we present ideas and concerns about the current state of knowledge on nanomaterials in the environment and present a number of points about what recent work has provided us about the novel materials.  相似文献   

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Postma E 《PloS one》2007,2(10):e999
Amongst the numerous problems associated with the use of impact factors as a measure of quality are the systematic differences in impact factors that exist among scientific fields. While in theory this can be circumvented by limiting comparisons to journals within the same field, for a diverse and multidisciplinary field like evolutionary biology, in which the majority of papers are published in journals that publish both evolutionary and non-evolutionary papers, this is impossible. However, a journal's overall impact factor may well be a poor predictor for the impact of its evolutionary papers. The extremely high impact factors of some multidisciplinary journals, for example, are by many believed to be driven mostly by publications from other fields. Despite plenty of speculation, however, we know as yet very little about the true impact of evolutionary papers in journals not specifically classified as evolutionary. Here I present, for a wide range of journals, an analysis of the number of evolutionary papers they publish and their average impact. I show that there are large differences in impact among evolutionary and non-evolutionary papers within journals; while the impact of evolutionary papers published in multidisciplinary journals is substantially overestimated by their overall impact factor, the impact of evolutionary papers in many of the more specialized, non-evolutionary journals is significantly underestimated. This suggests that, for evolutionary biologists, publishing in high-impact multidisciplinary journals should not receive as much weight as it does now, while evolutionary papers in more narrowly defined journals are currently undervalued. Importantly, however, their ranking remains largely unaffected. While journal impact factors may thus indeed provide a meaningful qualitative measure of impact, a fair quantitative comparison requires a more sophisticated journal classification system, together with multiple field-specific impact statistics per journal.  相似文献   

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Psychotherapy in its traditional form is being challenged due to managed care pressures. Psychotherapy using the model of health psychology can adapt well in a managed care environment. Differences between traditional psychotherapy and the psychotherapeutic approach of health psychology are discussed in this article, with a focus on an overview of health psychology and its applications to primary care, and the concept of single-session therapy. A case example of a sample treatment emphasizing the model of brief health psychology treatment is illustrated.  相似文献   

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《Ecological Indicators》2005,5(3):207-212
Analysis of a recently validated fragmentation index, named ‘coherence’, shows a direct relationship with the Simpson and Shannon indices. Since these diversity metrics are also denoted as ‘entropy metrics’, it can be accepted that patch size heterogeneity can adequately be described by an entropy metric. Since both indices are used to determine the entropy of a sample, the Brillouin index should be applied instead to correctly determine the entropy of a landscape pattern, this because this latter index is developed for fully censused data sets, such as landscapes when a complete coverage by cartographic data or imagery is available. Calculation of the Brillouin entropy index for three specific sites located in Cadiz Township (USA), the Poole Basin (Dorset, UK) and Sao Paulo State (Brazil), respectively, and using long-term data of patch size diversity, reveals increasing entropy levels associated with anthropogenic land cover dynamics (fragmentation). The observed entropy trends defy the laws of thermodynamics and signal the impact of human action on landscape integrity.  相似文献   

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Later this month the government will be consulting on whether the environment should be adopted as a new key area for their Health of the Nation strategy. It is proposing to have five topic areas and to adopt 10-15 environmental targets. This would reaffirm its commitment to linking environmental policy and health policy following publication earlier this year of its environmental health action plan. Critics may respond to the consultation document with suggestions for more far reaching targets--based, for example, on the "Health for All" targets from the World Health Organisation, or those arising out of Agenda 21 from the earth summit in Rio De Janeiro. Whatever the criticism, this move will be a chance to link environmental and health agendas at both national and local level.  相似文献   

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Background

It is important for health policy and expenditure projections to understand the relationship between age, death and expenditure on health care (HC). Research has shown that older age groups incur lower hospital costs than previously anticipated and that remaining time to death (TTD) was a much stronger indicator for expenditure than age. How health behaviour or risk factors impact on HC utilisation and costs at the end of life is relatively unknown. Smoking and Body Mass Index (BMI) have featured most prominently and mixed findings exist as to the exact nature of this association.

Methods

This paper considers the relationship between TTD, age and expenditure for inpatient care in the last 12 quarters of life; and introduces measures of health status and risks. A longitudinal dataset covering 35 years is utilised, including baseline survey data linked to hospital and death records. The effect of age, TTD and health indicators on expenditure for inpatient care is estimated using a two-part model.

Results

As individuals approach death costs increase. This effect is highly significant (p<0.01) from the last until the 8th quarter before death and influenced by age. Statistically significant effects on costs were found for: smoking status, systolic blood pressure and lung function (FEV1). On average, smokers incurred lower quarterly costs in their last 12 quarters of life than non-smokers (~7%). Participants’ BMI at baseline did show a negative association with probability of HC utilisation however this effect disappeared when costs were estimated.

Conclusions

Health risk measures obtained at baseline provide a good indication of individuals’ probability of needing medical attention later in life and incurring costs, despite the small size of the effect. Utilising a linked dataset, where such measures are available can add substantially to our ability to explain the relationship between TTD and costs.  相似文献   

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Background

China’s rapidly changing economic landscape has led to widening social inequalities. Occupational status in terms of occupational type and prestige may reflect these socio-structural shifts of social position and be more predictive of self-rated health status than income and education, which may only reflect more gradual acquisitions of social status over time. The goals of this study were to understand the role of occupational status in predicting self-rated health, which is well known to be associated with long-term mortality, as well as compare the occupational status to the other major socioeconomic indicators of income and education.

Methods

Data from the 2010 baseline surveys of the China Family Panel Studies, which utilized multi-stage probability sampling with implicit stratification was used. Logistic regression was used to examine the relationship of various socioeconomic indicators (i.e. occupational status, income, and education) with self-rated health as the primary outcome of interest. A series of models considered the associations of occupational category or occupational prestige with self-rated health.

Results

The final sample consisted of 14,367 employed adults aged 18–60, which was nationally representative of working adults in China. We found that occupation was not a major predictor of self-rated health in China when age, ethnicity, location, marital status, physical and mental health status were controlled for, with the exception of women working in lower grade management and professional jobs (OR = 1.82, 95% CI: 1.03–3.22). In comparison, income followed by education exhibited greater association with self-rated health. The highest income group had the least probability to report poor health (In men: OR = 0.30, 95% CI: 0.21–0.43. In women: OR = 0.44, 95% CI: 0.26–0.73). People educated with junior high school had better self-rated health than those with primary and below education level (In men: OR = 0.62, 95% CI: 0.50–0.75. In women: OR = 0.53, 95% CI: 0.42–0.68). Income, education and occupation were correlated with each other.

Conclusions

Within the context of rapid societal changes in China, income and its implications for greater healthcare access and benefits had the greatest association with self-rated health followed by education. Occupational status was not associated. Occupational categories and prestige should be better adapted to reflect China’s unique sociopolitical and historical context.  相似文献   

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Climate change has ignited lively research into its impact on various population-level processes. The research agenda in ecology says that some of the fluctuations in population size are accountable for by the external noise (e.g. weather) modulating the dynamics of populations. We obeyed the agenda by assuming population growth after a resource-limited Leslie matrix model in an age-structured population. The renewal process was disturbed by superimposing noise on the development of numbers in one or several age groups. We constructed models for iteroparous and semelparous breeders so that, for both categories, the population growth rate was matching. We analysed how the modulated population dynamics correlates with the noise signal with different time-lags. No significant correlations were observed for semelparous breeders, whereas for iteroparous breeders high correlations were frequently observed with time-lags of 71 year or longer. However, the latter occurs under red-coloured noise and for low growth rates when the disturbance is on the youngest age group only. It is laborious to find any clear signs of the (red) noise- and age group-specific fluctuations if the disturbance influences older age groups only. These results cast doubts on the possibility of detecting the signature of external disturbance after it has modulated temporal fluctuations in age-structured populations.  相似文献   

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