800 resultados para Ecological risk assessment


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Research on endocrine disruption in fish has been dominated by studies on estrogen-active compounds which act as mimics of the natural estrogen, 17β-estradiol (E2), and generally exert their biological actions by binding to and activation of estrogen receptors (ERs). Estrogens play central roles in reproductive physiology and regulate (female) sexual differentiation. In line with this, most adverse effects reported for fish exposed to environmental estrogens relate to sexual differentiation and reproduction. E2, however, utilizes a variety of signaling mechanisms, has multifaceted functions and targets, and therefore the toxicological and ecological effects of environmental estrogens in fish will extend beyond those associated with the reproduction. This review first describes the diversity of estrogen receptor signaling in fish, including both genomic and non-genomic mechanisms, and receptor crosstalk. It then considers the range of non-reproductive physiological processes in fish that are known to be responsive to estrogens, including sensory systems, the brain, the immune system, growth, specifically through the growth hormone/insulin-like growth factor system, and osmoregulation. The diversity in estrogen responses between fish species is then addressed, framed within evolutionary and ecological contexts, and we make assessments on their relevance for toxicological sensitivity as well as ecological vulnerability. The diversity of estrogen actions raises questions whether current risk assessment strategies, which focus on reproductive endpoints, and a few model fish species only, are protective of the wider potential health effects of estrogens. Available - although limited - evidence nevertheless suggests that quantitative environmental threshold concentrations for environmental protection derived from reproductive tests with model fish species are protective for non-reproductive effects as well. The diversity of actions of estrogens across divergent physiological systems, however, may lead to and underestimation of impacts on fish populations as their effects are generally considered on one functional process only and this may underrepresent the impact on the different physiological processes collectively.

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This study analysed mechanisms through which stress-coping and temptation-coping strategies were associated with lapses. Furthermore, we explored whether distinct coping strategies differentially predicted reduced lapse risk, lower urge levels, or a weaker association between urge levels and lapses during the first week of an unassisted smoking cessation attempt. Participants were recruited via the internet and mass media in Switzerland. Ecological momentary assessment (EMA) with mobile devices was used to assess urge levels and lapses. Online questionnaires were used to measure smoking behaviours and coping variables at baseline, as well as smoking behaviour at the three-month follow-up. The sample consisted of 243 individuals, aged 20 to 40, who reported 4199 observations. Findings of multilevel regression analyses show that coping was mainly associated with a reduced lapse risk and not with lower urge levels or a weaker association between urge levels and lapses. 'Calming down' and 'commitment to change' predicted a lower lapse risk and also a weaker relation between urge levels and lapses. 'Stimulus control' predicted a lower lapse risk and lower urge levels. Conversely, 'task-orientation' and 'risk assessment' were related to higher lapse risk and 'risk assessment' also to higher urge levels. Disengagement coping i.e. 'eating or shopping', 'distraction', and 'mobilising social support' did not affect lapse risk. Promising coping strategies during the initial stage of smoking cessation attempt are targeted directly at reducing the lapse risk and are characterised by engagement with the stressor or one's reactions towards the stressor and a focus on positive consequences instead of health risks.

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The design of efficient hydrological risk mitigation strategies and their subsequent implementation relies on a careful vulnerability analysis of the elements exposed. Recently, extensive research efforts were undertaken to develop and refine empirical relationships linking the structural vulnerability of buildings to the impact forces of the hazard processes. These empirical vulnerability functions allow estimating the expected direct losses as a result of the hazard scenario based on spatially explicit representation of the process patterns and the elements at risk classified into defined typological categories. However, due to the underlying empiricism of such vulnerability functions, the physics of the damage-generating mechanisms for a well-defined element at risk with its peculiar geometry and structural characteristics remain unveiled, and, as such, the applicability of the empirical approach for planning hazard-proof residential buildings is limited. Therefore, we propose a conceptual assessment scheme to close this gap. This assessment scheme encompasses distinct analytical steps: modelling (a) the process intensity, (b) the impact on the element at risk exposed and (c) the physical response of the building envelope. Furthermore, these results provide the input data for the subsequent damage evaluation and economic damage valuation. This dynamic assessment supports all relevant planning activities with respect to a minimisation of losses, and can be implemented in the operational risk assessment procedure.

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BACKGROUND Heart failure with preserved ejection fraction (HFpEF) represents a growing health burden associated with substantial mortality and morbidity. Consequently, risk prediction is of highest importance. Endothelial dysfunction has been recently shown to play an important role in the complex pathophysiology of HFpEF. We therefore aimed to assess von Willebrand factor (vWF), a marker of endothelial damage, as potential biomarker for risk assessment in patients with HFpEF. METHODS AND RESULTS Concentrations of vWF were assessed in 457 patients with HFpEF enrolled as part of the LUdwigshafen Risk and Cardiovascular Health (LURIC) study. All-cause mortality was observed in 40% of patients during a median follow-up time of 9.7 years. vWF significantly predicted mortality with a hazard ratio (HR) per increase of 1 SD of 1.45 (95% confidence interval, 1.26-1.68; P<0.001) and remained a significant predictor after adjustment for age, sex, body mass index, N-terminal pro-B-type natriuretic peptide (NT-proBNP), renal function, and frequent HFpEF-related comorbidities (adjusted HR per 1 SD, 1.22; 95% confidence interval, 1.05-1.42; P=0.001). Most notably, vWF showed additional prognostic value beyond that achievable with NT-proBNP indicated by improvements in C-Statistic (vWF×NT-proBNP: 0.65 versus NT-proBNP: 0.63; P for comparison, 0.004) and category-free net reclassification index (37.6%; P<0.001). CONCLUSIONS vWF is an independent predictor of long-term outcome in patients with HFpEF, which is in line with endothelial dysfunction as potential mediator in the pathophysiology of HFpEF. In particular, combined assessment of vWF and NT-proBNP improved risk prediction in this vulnerable group of patients.

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Engineered nanomaterials have unique and novel properties enabling wide-ranging new applications in nearly all fields of research. As these new properties have raised concerns about potential adverse effects for the environment and human health, extensive efforts are underway to define reliable, cost- and time-effective, as well as mechanistic-based testing strategies to replace the current method of animal testing, which is still the most prevalent model used for the risk assessment of chemicals. Current approaches for nanomaterials follow this line. The aim of this review is to explore and qualify the relevance of new in vitro and ex vivo models in (nano)material safety assessment, a crucial prerequisite for translation into applications.

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SOLUTIONS (2013 to 2018) is a European Union Seventh Framework Programme Project (EU-FP7). The project aims to deliver a conceptual framework to support the evidence-based development of environmental policies with regard to water quality. SOLUTIONS will develop the tools for the identification, prioritisation and assessment of those water contaminants that may pose a risk to ecosystems and human health. To this end, a new generation of chemical and effect-based monitoring tools is developed and integrated with a full set of exposure, effect and risk assessment models. SOLUTIONS attempts to address legacy, present and future contamination by integrating monitoring and modelling based approaches with scenarios on future developments in society, economy and technology and thus in contamination. The project follows a solutions-oriented approach by addressing major problems of water and chemicals management and by assessing abatement options. SOLUTIONS takes advantage of the access to the infrastructure necessary to investigate the large basins of the Danube and Rhine as well as relevant Mediterranean basins as case studies, and puts major efforts on stakeholder dialogue and support. Particularly, the EU Water Framework Directive (WFD) Common Implementation Strategy (CIS) working groups, International River Commissions, and water works associations are directly supported with consistent guidance for the early detection, identification, prioritisation, and abatement of chemicals in the water cycle. SOLUTIONS will give a specific emphasis on concepts and tools for the impact and risk assessment of complex mixtures of emerging pollutants, their metabolites and transformation products. Analytical and effect-based screening tools will be applied together with ecological assessment tools for the identification of toxicants and their impacts. The SOLUTIONS approach is expected to provide transparent and evidence-based candidates or River Basin Specific Pollutants in the case study basins and to assist future review of priority pollutants under the WFD as well as potential abatement options.

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There is growing interest in providing women with internatal care, a package of healthcare and ancillary services that can improve their health during the period after the termination of one pregnancy but before the conception of the next pregnancy. Women who have had a pregnancy affected by a neural tube defect can especially benefit from internatal care because they are at increased risk for recurrence and improvements to their health during the inter-pregnancy period can prevent future negative birth outcomes. The dissertation provides three papers that inform the content of internatal care for women at risk for recurrence by examining descriptive epidemiology to develop an accurate risk profile of the population, assessing whether women at risk for recurrence would benefit from a psychosocial intervention, and determining how to improve health promotion efforts targeting folic acid use.^ Paper one identifies information relevant for developing risk profiles and conducting risk assessments. A number of investigations have found that the risk for neural tube defects differs between non-Hispanic Whites and Hispanics. To understand the risk difference, the descriptive epidemiology of spina bifida and anencephaly was examined for Hispanics and non-Hispanic Whites based on data from the Texas Birth Defects Registry for the years 1999 through 2004. Crude and adjusted birth prevalence ratios and corresponding 95% confidence intervals were calculated between descriptive epidemiologic characteristics and anencephaly and spina bifida for non-Hispanic Whites and for Hispanics. In both race/ethnic groups, anencephaly expressed an inverse relationship with maternal age and a positive linear relationship with parity. Both relationships were stronger in non-Hispanic Whites. Female infants had a higher risk for anencephaly in non-Hispanic Whites. Lower maternal education was associated with increased risk for spina bifida in Hispanics.^ Paper two assesses the need for a psychosocial intervention. For mothers who have children with spina bifida, the transition to motherhood can be stressful. This qualitative study explored the process of becoming a mother to a child with spina bifida focusing particularly on stress and coping in the immediate postnatal environment. Semi-structured interviews were conducted with six mothers who have children with spina bifida. Mothers were asked about their initial emotional and problem-based coping efforts, the quality and kind of support provided by health providers, and the characteristics of their meaning-based coping efforts; questions matched Transactional Model of Stress and Coping (TMSC) constructs. Analysis of the responses revealed a number of modifiable stress and coping transactions, the most salient being: health providers are in a position to address beliefs about self-causality and prevent mothers from experiencing the repercussions that stem from maintaining these beliefs. ^ Paper three identifies considerations when creating health promotion materials targeting folic acid use. A brochure was designed using concepts from the Precaution Adoption Process Model (PAPM). Three focus groups comprising 26 mothers of children with spina bifida evaluated the brochure. One focus group was conducted in Spanish-only, the other two focus groups were conducted in English and Spanish combined. Qualitative analysis of coded transcripts revealed that a brochure is a helpful adjunct. Questions about folic acid support the inclusion of an insert with basic information. There may be a need to develop different educational material for Hispanics so the importance of folic acid is provided in a situational context. Some participants blamed themselves for their pregnancy outcome which may affect their receptivity to messages in the brochure. The women's desire for photographs that affect their perception of threat and their identification with the second role model indicate they belong to PAPM Stage 2 and 3. Participants preferred colorful envelopes, high quality paper, intimidating photographs, simple words, conversational style sentences, and positive messages.^ These papers develop the content of risk assessment, psychosocial intervention, and health promotion components of internatal care as they apply to women at risk for recurrence. The findings provided evidence for considering parity and maternal age when assessing nutritional risk. The two dissimilarities between the two race/ethnic groups, infant sex and maternal education lent support to creating separate risk profiles. Interviews with mothers of children with spina bifida revealed the existence of unmet needs-suggesting that a psychosocial intervention provided as part of internatal care can strengthen and support women's well-being. Segmenting the audience according to race/ethnicity and PAPM stage can improve the relevance of print materials promoting folic acid use.^

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In order to better take advantage of the abundant results from large-scale genomic association studies, investigators are turning to a genetic risk score (GRS) method in order to combine the information from common modest-effect risk alleles into an efficient risk assessment statistic. The statistical properties of these GRSs are poorly understood. As a first step toward a better understanding of GRSs, a systematic analysis of recent investigations using a GRS was undertaken. GRS studies were searched in the areas of coronary heart disease (CHD), cancer, and other common diseases using bibliographic databases and by hand-searching reference lists and journals. Twenty-one independent case-control studies, cohort studies, and simulation studies (12 in CHD, 9 in other diseases) were identified. The underlying statistical assumptions of the GRS using the experience of the Framingham risk score were investigated. Improvements in the construction of a GRS guided by the concept of composite indicators are discussed. The GRS will be a promising risk assessment tool to improve prediction and diagnosis of common diseases.^

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Systems of Systems (SoS) present challenging features and existing tools result often inadequate for their analysis, especially for heteregeneous networked infrastructures. Most accident scenarios in networked systems cannot be addressed by a simplistic black or white (i.e. functioning or failed) approach. Slow deviations from nominal operation conditions may cause degraded behaviours that suddenly end up into unexpected malfunctioning, with large portions of the network affected. In this paper,we present a language for modelling networked SoS. The language makes it possible to represent interdependencies of various natures, e.g. technical, organizational and human. The representation of interdependencies is based on control relationships that exchange physical quantities and related information. The language also makes it possible the identification of accident scenarios, by representing the propagation of failure events throughout the network. The results can be used for assessing the effectiveness of those mechanisms and measures that contribute to the overall resilience, both in qualitative and quantitative terms. The presented modelling methodology is general enough to be applied in combination with already existing system analysis techniques, such as risk assessment, dependability and performance evaluation

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The design of nuclear power plant has to follow a number of regulations aimed at limiting the risks inherent in this type of installation. The goal is to prevent and to limit the consequences of any possible incident that might threaten the public or the environment. To verify that the safety requirements are met a safety assessment process is followed. Safety analysis is as key component of a safety assessment, which incorporates both probabilistic and deterministic approaches. The deterministic approach attempts to ensure that the various situations, and in particular accidents, that are considered to be plausible, have been taken into account, and that the monitoring systems and engineered safety and safeguard systems will be capable of ensuring the safety goals. On the other hand, probabilistic safety analysis tries to demonstrate that the safety requirements are met for potential accidents both within and beyond the design basis, thus identifying vulnerabilities not necessarily accessible through deterministic safety analysis alone. Probabilistic safety assessment (PSA) methodology is widely used in the nuclear industry and is especially effective in comprehensive assessment of the measures needed to prevent accidents with small probability but severe consequences. Still, the trend towards a risk informed regulation (RIR) demanded a more extended use of risk assessment techniques with a significant need to further extend PSA’s scope and quality. Here is where the theory of stimulated dynamics (TSD) intervenes, as it is the mathematical foundation of the integrated safety assessment (ISA) methodology developed by the CSN(Consejo de Seguridad Nuclear) branch of Modelling and Simulation (MOSI). Such methodology attempts to extend classical PSA including accident dynamic analysis, an assessment of the damage associated to the transients and a computation of the damage frequency. The application of this ISA methodology requires a computational framework called SCAIS (Simulation Code System for Integrated Safety Assessment). SCAIS provides accident dynamic analysis support through simulation of nuclear accident sequences and operating procedures. Furthermore, it includes probabilistic quantification of fault trees and sequences; and integration and statistic treatment of risk metrics. SCAIS comprehensively implies an intensive use of code coupling techniques to join typical thermal hydraulic analysis, severe accident and probability calculation codes. The integration of accident simulation in the risk assessment process and thus requiring the use of complex nuclear plant models is what makes it so powerful, yet at the cost of an enormous increase in complexity. As the complexity of the process is primarily focused on such accident simulation codes, the question of whether it is possible to reduce the number of required simulation arises, which will be the focus of the present work. This document presents the work done on the investigation of more efficient techniques applied to the process of risk assessment inside the mentioned ISA methodology. Therefore such techniques will have the primary goal of decreasing the number of simulation needed for an adequate estimation of the damage probability. As the methodology and tools are relatively recent, there is not much work done inside this line of investigation, making it a quite difficult but necessary task, and because of time limitations the scope of the work had to be reduced. Therefore, some assumptions were made to work in simplified scenarios best suited for an initial approximation to the problem. The following section tries to explain in detail the process followed to design and test the developed techniques. Then, the next section introduces the general concepts and formulae of the TSD theory which are at the core of the risk assessment process. Afterwards a description of the simulation framework requirements and design is given. Followed by an introduction to the developed techniques, giving full detail of its mathematical background and its procedures. Later, the test case used is described and result from the application of the techniques is shown. Finally the conclusions are presented and future lines of work are exposed.

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Colombia is one of the largest per capita mercury polluters in the world as a consequence of its artisanal gold mining activities. The severity of this problem in terms of potential health effects was evaluated by means of a probabilistic risk assessment carried out in the twelve departments (or provinces) in Colombia with the largest gold production. The two exposure pathways included in the risk assessment were inhalation of elemental Hg vapors and ingestion of fish contaminated with methyl mercury. Exposure parameters for the adult population (especially rates of fish consumption) were obtained from nation-wide surveys and concentrations of Hg in air and of methyl-mercury in fish were gathered from previous scientific studies. Fish consumption varied between departments and ranged from 0 to 0.3 kg d?1. Average concentrations of total mercury in fish (70 data) ranged from 0.026 to 3.3 lg g?1. A total of 550 individual measurements of Hg in workshop air (ranging from menor queDL to 1 mg m?3) and 261 measurements of Hg in outdoor air (ranging from menor queDL to 0.652 mg m?3) were used to generate the probability distributions used as concentration terms in the calculation of risk. All but two of the distributions of Hazard Quotients (HQ) associated with ingestion of Hg-contaminated fish for the twelve regions evaluated presented median values higher than the threshold value of 1 and the 95th percentiles ranged from 4 to 90. In the case of exposure to Hg vapors, minimum values of HQ for the general population exceeded 1 in all the towns included in this study, and the HQs for miner-smelters burning the amalgam is two orders of magnitude higher, reaching values of 200 for the 95th percentile. Even acknowledging the conservative assumptions included in the risk assessment and the uncertainties associated with it, its results clearly reveal the exorbitant levels of risk endured not only by miner-smelters but also by the general population of artisanal gold mining communities in Colombia.

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This paper presents an assessment analysis of damage domains of the 30 MWth prototype High-Temperature Engineering Test Reactor (HTTR) operated by the Japan Atomic Energy Agency (JAEA). For this purpose, an in-house deterministic risk assessment computational tool was developed based on the Theory of Stimulated Dynamics (TSD). To illustrate the methodology and applicability of the developed modelling approach, assessment results of a control rod (CR) withdrawal accident during subcritical conditions are presented and compared with those obtained by the JAEA.

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Widespread interest in producing transgenic organisms is balanced by concern over ecological hazards, such as species extinction if such organisms were to be released into nature. An ecological risk associated with the introduction of a transgenic organism is that the transgene, though rare, can spread in a natural population. An increase in transgene frequency is often assumed to be unlikely because transgenic organisms typically have some viability disadvantage. Reduced viability is assumed to be common because transgenic individuals are best viewed as macromutants that lack any history of selection that could reduce negative fitness effects. However, these arguments ignore the potential advantageous effects of transgenes on some aspect of fitness such as mating success. Here, we examine the risk to a natural population after release of a few transgenic individuals when the transgene trait simultaneously increases transgenic male mating success and lowers the viability of transgenic offspring. We obtained relevant life history data by using the small cyprinodont fish, Japanese medaka (Oryzias latipes) as a model. Our deterministic equations predict that a transgene introduced into a natural population by a small number of transgenic fish will spread as a result of enhanced mating advantage, but the reduced viability of offspring will cause eventual local extinction of both populations. Such risks should be evaluated with each new transgenic animal before release.

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Over the last thirty years or so, as the number of in-house counsel rose and their role increased in scope and prominence, increased attention has been given the various challenges these lawyers face under the ABA Model Rules of Professional Conduct, from figuring out who is the client the in-house lawyer represents, to navigating conflicts of interest, maintaining independence, and engaging in a multijurisdictional practice of law. Less attention, to date, has been given to business risk assessment, perhaps in part because that function appears to be part of in-house counsel’s role as a business person rather than as a lawyer. Overlooking the role of in-house counsel in assessing risk, however, is a risky proposition, because risk assessment constitutes for some in-house counsel a significant aspect of their role, a role that in turn informs and shapes how in-house counsel perform other more overtly legal tasks. For example, wearing her hat as General Counsel, a lawyer for the entity-client may opine and explain issues of compliance with the law. Wearing her hat as the Chief Legal Officer, however, the same lawyer may now be called upon as a member of business management to participate in the decision whether to comply with the law. After outlining some of the traditional challenges faced by in-house counsel under the Rules, this short essay explores risk assessment by in-house counsel and its impact on their role and function under the Rules. It argues that the key to in-house lawyers’ successful navigation of multiple roles, and, in particular, to their effective assessment of business risk is keen awareness of the various hats they are called upon to wear. Navigating these various roles may not be easy for lawyers, whose training and habits of mind often teach them to zoom in on legal risks to the exclusion of business risks. Indeed, law schools continue to teach law students “to think like a lawyer” and law firms, the historical breeding grounds for in-house counsel positions, in a world of increased specialization master the narrower contemplation of legal questions. Yet the present and future of in-house counsel practice demand of its practitioners the careful and gradual coming to terms, buildup and mastery of business risk analysis skills, alongside the cultivation of traditional legal risk analysis tools.