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101.
《Risk analysis》2018,38(10):2029-2040
The Chippewa Ottawa Resource Authority monitors fish contaminants in Anishinaabe (Great Lake Native American) tribal fisheries. This article updates previously reported trends in two persistent bioaccumulative toxic (PBT) substances that are the primary contributors to consumption advisory limits for these fish: methylmercury (MeHg) and polychlorinated biphenyls (PCBs). Also, we report, for the first time, an analysis of nutritional benefit bioindicators and metrics in these same Upper Great Lakes fish harvests: selenium (Se) and omega‐3 fatty acids (PUFA‐3s). A novel risk/benefit quantification originally presented by Ginsberg et al. is reported here to characterize the tradeoffs between fatty acid benefits and toxic MeHg health outcomes. We also report a Se benefit metric to characterize the possible protective value against MeHg neurotoxicity based on Ralston et al. Congruent with Anishinaabe cultural motivations to consume fish from their ancestral fisheries, nutritional content was high in locally caught fish and, in some respects, superior to farmed/store‐bought fish. These Great Lakes fish still contained levels of PBTs that require careful education and guidance for consumers. However, the contaminant trends suggest that these fish need not be abandoned as important (both culturally and nutritionally) food sources for the Anishinaabe who harvested them. 相似文献
102.
《Risk analysis》2018,38(9):1988-2009
Harbor seals in Iliamna Lake, Alaska, are a small, isolated population, and one of only two freshwater populations of harbor seals in the world, yet little is known about their abundance or risk for extinction. Bayesian hierarchical models were used to estimate abundance and trend of this population. Observational models were developed from aerial survey and harvest data, and they included effects for time of year and time of day on survey counts. Underlying models of abundance and trend were based on a Leslie matrix model that used prior information on vital rates from the literature. We developed three scenarios for variability in the priors and used them as part of a sensitivity analysis. The models were fitted using Markov chain Monte Carlo methods. The population production rate implied by the vital rate estimates was about 5% per year, very similar to the average annual harvest rate. After a period of growth in the 1980s, the population appears to be relatively stable at around 400 individuals. A population viability analysis assessing the risk of quasi‐extinction, defined as any reduction to 50 animals or below in the next 100 years, ranged from 1% to 3%, depending on the prior scenario. Although this is moderately low risk, it does not include genetic or catastrophic environmental events, which may have occurred to the population in the past, so our results should be applied cautiously. 相似文献
103.
为了削弱传统零售商在渠道博弈中的垄断地位,制造商尝试建立在线渠道与零售商展开竞争。本文在考虑消费者低碳偏好的基础上,又将消费者的渠道偏好进行区分,通过不同决策模式的对比及数值算例分析,寻求低碳供应链最优的减排边界。研究表明:1分散决策时,制造商的低碳决策会受消费者渠道偏好的影响;集中决策时,制造商的低碳决策保持不变。2不同决策模式的减排边界由渠道偏好决定,渠道偏好较大时,分散决策的减排边界更高;渠道偏好较低时,集中决策的减排边界更高;渠道偏好中立时,两者的减排边界相同。3制造商可以通过升级低碳技术、实行低碳化管理等方式降低减排成本,同时通过低碳产品认证、广告宣传等方式提高消费者对低碳产品的认可程度。 相似文献
104.
将灰色模糊数扩展,定义了区间灰色区间数及其距离.针对准则值为区间灰色区间数的信息不完全的多准则决策问题,提出了一种基于目标规划法的灰色模糊多准则决策方法,求得最优权重向量,从而得到各方案的排序.最后给出一个算例说明方法的可行性和有效性. 相似文献
105.
Most recommerce providers have moved to a quality‐dependent process for the acquisition of used products. They acquire the products via websites at which product holders submit upfront quality statements and receive quality‐dependent acquisition prices for their used devices. Motivated by this development of reverse logistics practice, the aim of this study is to analyze the product assessment process of a recommerce provider in detail. To this end, we first propose a sequential bargaining model with complete information which captures the individual behavior of the recommerce provider and the product holder. We determine the optimal strategies of the product holder and the recommerce provider in this game. We find that the resulting strategies lead to an efficient allocation, although the recommerce provider can absorb most of the bargaining potential due to his last mover advantage. In a second step, we relax the assumption of complete information and include uncertainty about the product holder's valuation of the product. We show the trade‐off underlying the recommerce provider's optimal counteroffer decision and analyze the optimal strategy, using a logistic regression approach on a real‐life dataset of nearly 6,000 product submissions. The results reveal a significant improvement potential, compared to the currently applied strategy. 相似文献
106.
107.
Parents at‐risk and their children: intersections of gender role attitudes and parenting practices 下载免费PDF全文
Jordan E. Montgomery Casey L. Chaviano Allison D. Rayburn Lenore M. McWey 《Child & Family Social Work》2017,22(3):1151-1160
Existing research demonstrates that parent and child gender may influence important aspects of family relationships; however, most research in this area has been conducted with non‐clinical samples. As clinicians, it is important to consider how gender impacts family relationships, particularly among vulnerable families. This study examined the intersections of gender role attitudes and parenting practices among 34 parents involved with the child welfare system and referred for clinical intervention. Using a mixed methods design, themes regarding gender role beliefs and parenting practices were found through qualitative interviews with parents. Findings suggested that fathers felt responsible for financially providing for their families and expressed challenges in communicating with mothers, and mothers described challenges they face because of a lack of father involvement. Parents also discussed a perceived need to monitor daughters closely while fostering the independence of their sons. Results of the qualitative analyses were supported by quantitative findings indicating significant differences in harsh and inconsistent discipline practices and clear expectations for girls compared to boys. The discussion addresses implications for clinicians, including how a feminist family therapy perspective may help promote client influence over traditional gender norms by questioning gender role attitudes and exploring alternate narratives that may impact family dynamics. 相似文献
108.
Georgia's national social security system offers almost universal non‐contributory basic pension coverage. The basic pension has, to date, proved effective in dealing with old‐age poverty. But Georgia's fiscal constraints and ageing population also highlight the importance of improving the pension system, in order to ensure its sustainability. This article presents policy reform choices, which suggest that, in Georgia, pension reform might include increasing the statutory retirement ages and reducing the generosity of benefits through means testing. The case of the Georgian non‐contributory basic pension might hold value for some low‐ and middle‐income countries that are considering the implementation of, or expanding coverage under, a non‐contributory pension programme. 相似文献
109.
Story stem measures are an increasingly popular method for assessing the attachment representations of young children, but little is known of their cross‐cultural applicability. This study aimed to characterise the attachment representations in 73 five‐ to eight‐year‐old children in urban Ghana, West Africa, using the Manchester Child Attachment Story Task (MCAST) to test its feasibility, psychometric characteristics and concurrent associations with caregiver‐ and teacher‐rated child behaviour, and to conduct a qualitative thematic analysis of methodological observations. Among the classifiable cases (92 percent), all attachment classifications were observed, yielding a higher rate of secure attachment than in European samples. Inter‐rater reliability, internal consistency, and internal structure were reasonable and largely similar to European studies, although one structural difference was the separation of ‘child assuagement of distress’ from other secure‐related items. MCAST narratives were associated with teacher‐ and caregiver‐rated hyperactivity, but internal consistency was low in most Strengths and Difficulties Questionnaire scales. Possible culturally‐sensitive explanations for our psychometric and qualitative findings are discussed. Overall, story stems are a promising tool for accessing attachment representations in non‐Western samples, although modifications are likely to improve cross‐cultural equivalence when applied to non‐Western cultures. Further investigation is needed to link MCAST outcomes to parenting and socio‐emotional development. 相似文献
110.
Education is one major public service in which quasi‐markets and other choice‐based mechanisms are now established methods of delivery. The types of school people choose, and the extent to which their choices are realized, have a fundamental impact on the outcomes of any mechanism of school choice. In this article, we provide a comparative analysis of the school choice strategies of middle‐class families in London and Paris. We draw on approximately 200 in‐depth interviews carried out across the two cities. This enables us to investigate the extent to which middle‐class school choice strategies transcend the institutional context provided by both the local (state and private) schools market and national education policy in England and France. We discuss these findings in the context of current school choice policy and consider their implications for future policy design. 相似文献