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Abstract: Considerable attention has recently been focused on using levels of developmental instability among members of a population to detect environmental or genetic stresses on animals or plants. It is not yet clear, however, that high developmental instability in a sample of individuals always indicates environmental stress or poor genetic quality. We studied 13 fragmented populations of prairie phlox (   Phlox pilosa L.) to test the hypothesis that developmental instability should decrease with increasing population size—as expected if small populations suffer genetic problems associated with inbreeding or are exposed to more environmental stress than larger populations. We used two different measures of developmental instability, each calculated for two different traits: radial asymmetry of flowers (for petal width and petal length) and modular fluctuating asymmetry of leaves (  for leaf widths at two points along the leaf  ). There were weak but significant correlations among individuals for four of six pairwise combinations of these measures. Surprisingly, three of our four measures of developmental instability showed strong population size effects that were opposite to those expected: developmental instability increased with population size. We conclude that measures of developmental instability cannot be applied uncritically for biomonitoring without considerable knowledge of developmental mechanisms, natural history, and population biology of the species in question.  相似文献   
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Implementing the UNCCD: Participatory challenges   总被引:1,自引:0,他引:1  
The United Nations Convention to Combat Desertification (UNCCD) emphasizes the need for public participation in land degradation assessment and rehabilitation. While participatory approaches are supported by a growing body of research and practice, meaningfully involving the people affected by land degradation is far from straightforward. This paper investigates the challenge of using the UNCCD as a guide to influence community participation in policy‐making and practice at national and local levels by analyzing experiences from three southern African countries. We show that the UNCCD represents a useful normative framework for addressing degradation problems, but that the participatory ethos is difficult to enact at the national level. Whilst there is increasing evidence that combining local and scientific knowledge using participatory mechanisms can deliver the benefits that the Convention strives to achieve, communication between researchers and practitioners, and those involved in implementing the UNCCD at the national level needs to be strengthened. Broad lessons and best practices in incorporating participatory practices into policy development are elucidated. Our case studies show that a range of mixed‐method, interdisciplinary approaches can enable policy‐makers and practitioners to meaningfully engage those who are affected by land degradation in its definition, assessment and rehabilitation.  相似文献   
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With improvements in early diagnosis and management of genetic diseases, more women with genetic disorders are reaching reproductive age and becoming pregnant. While pregnancy can have a significant impact on a woman's health when there is an underlying genetic disorder, there can also be fetal effects, including embryopathy, fetal growth restriction, and brain injury. Some maternal genetic disorders are associated with adverse perinatal outcomes, including a high risk of perinatal loss and preterm birth. In this article, we review several maternal genetic disorders associated with fetal risk that are important for clinicians and patients to understand and manage appropriately. These include phenylalanine hydroxylase (PAH) deficiency and other inborn errors of metabolism, tuberous sclerosis complex, myotonic dystrophy, cystic fibrosis, Turner syndrome, sickle cell disease, and connective tissue disorders.  相似文献   
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This article presents a case study of an accelerated cleanup conducted by EPA at the Adams Plating Company (APC) Superfund site near Lansing, Michigan. The APC site remediation was a Superfund EPA-lead project under the remedial program in Region 5. An accelerated cleanup was possible at the APC site by consistently identifying, evaluating, and implementing opportunities to streamline the remedial investigation (RI) and remedial design (RD) process. Streamlining opportunities were discovered and implemented in both the technical and administrative aspects of the project. Streamlining components used to accelerate the remedial process included: (1) extensive use of field screening techniques during the Phase II RI; (2) a focused feasibility study (FS) that evaluated only practical alternatives; (3) maintaining project momentum by initiating the RD concurrent with the issuance of the Record of Decision (ROD); (4) a highly accelerated RD with limited predesign work; (5) elimination of the transition period between RD and remedial action (RA) project phases; (6) frequent and effective communication, coordination, and cooperation between all parties involved (EPA, Michigan Department of Natural Resources (MDNR), technical contractor, PRC Environmental Management, Inc. (PRC), and the public); (7) maintaining a consistent project team throughout project duration; and (8) the setting of aggressive project goals.  相似文献   
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