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221.
Children, who are vulnerable at the start of existence, are a concern shared by nations and cultures. The importance of children's conditions has led 192 out of 194 countries to ratify the UN General Assembly's Convention on the Rights of the Child. The United States has not yet ratified the convention, despite having exercised influence on the drafting of its provisions. Given the global importance of nurturing and protecting children, the Society for Medical Anthropology strongly and emphatically supports that the convention be ratified, and that the U.S. government submit the convention for approval by the U.S. Senate.  相似文献   
222.
Albinism represents a group of genetic disorders with a broad spectrum of hypopigmentary phenotypes dependent on the genetic background of the patients. Oculocutaneous albinism (OCA) patients have little or no pigment in their eyes, skin and hair, whereas ocular albinism (OA) primarily presents the ocular symptoms, and the skin and hair color may vary from near normal to very fair. Mutations in genes directly or indirectly regulating melanin production are responsible for different forms of albinism with overlapping clinical features. In this study, 27 albinistic individuals from 24 families were screened for causal variants by a PCR-sequencing based approach. TYR, OCA2, TYRP1, SLC45A2, SLC24A5, TYRP2 and SILV were selected as candidate genes. We identified 5 TYR and 3 OCA2 mutations, majority in homozygous state, in 8 unrelated patients including a case of autosomal recessive ocular albinism (AROA). A homozygous 4-nucleotide novel insertion in SLC24A5 was detected in a person showing with extreme cutaneous hypopigmentation. A potential causal variant was identified in the TYRP2 gene in a single patient. Haplotype analyses in the patients carrying homozygous mutations in the classical OCA genes suggested founder effect. This is the first report of an Indian AROA patient harboring a mutation in OCA2. Our results also reveal for the first time that mutations in SLC24A5 could contribute to extreme hypopigmentation in humans.  相似文献   
223.
Although appearing in the literature as early as 1890, the brown lemur form Eulemur cinereiceps has recently resurfaced as a potentially valid taxon, distinct from neighboring, presumably closely related species such as white-collared lemurs (Eulemur albocollaris). We propose two scenarios for the potential separation of E. cinereiceps and E. albocollaris: (1) coastal and interior populations represent two distinct taxa and (2) the coastal population north of the Manampatrana River (the locality for purported museum specimens of E. cinereiceps) represents a distinct species from E. albocollaris found south of the river and in the interior escarpment forests. We tested these hypotheses using data from ground surveys and genetic sampling. Surveys were conducted in coastal forest fragments both north and south of the Manampatrana River in July-August 2006. Genetic samples were collected at two coastal sites and one interior forest. We used maximum parsimony, maximum likelihood, and neighbor-joining analyses on mitochondrial DNA regions to determine if populations from different sites clustered into diagnosable clades. Results from field surveys confirmed the presence of forms commonly referred to as E. albocollaris at the two southern coastal forests; no consistent phenotypic differences across sites were observed. All genetic analyses yielded identical results: coastal and interior populations do not cluster into separate groups, thus rejecting the first hypothesis. Eulemur species and all other day-active lemurs have apparently been extirpated from coastal forests north of the Manampatrana. Owing to the absence of lemurs from the northern coastal localities, we could not conclusively support or reject the second scenario. However, based on examination of the original plates and museum specimens, as well as the biogeographic patterns typical of this region, we strongly suspect that all populations from this area belong to a single species. We conclude with remarks regarding the apparent priority of E. cinereiceps for this taxon.  相似文献   
224.
The phytoremediation of trichloroethylene (TCE) from contaminated groundwater has been extensively studied using the hybrid poplar tree (Populus spp.). Several metabolites of TCE have been identified in the tissue of poplar including trichloroethanol (TCEOH) and dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA). In addition to the use of hybrid poplar for the phytoremediation of TCE, it is important to screen native tree species that could be successful candidates for field use. This study involves a greenhouse-based comparison of four different native southeastern conifers to a hybrid poplar species for their potential to phytoremediate TCE through the analysis of various plant tissues for TCE and major TCE metabolites, as well as several growth parameters that are desirable for phytoremediation. Longleaf pine (Pinus palustris), Leyland cypress (X Cupressocyparis leylandii), two varieties of Loblolly pine (Pinus taeda), and hybrid poplar species H11-11 (Populus trichocarpa x deltoides) were examined for the concentration of TCE and its metabolites in their tissue following treatment with either a low (50 mg L?1) or high dose of TCE (150 mg L?1) for 2 mo. The amount of water taken up, change in height of the tree, TCE transpiration, and total fresh weight of various tissue types were also measured. All trees contained detectable levels of TCE in their root and stem tissue. TCEOH was found only in the tissue of longleaf pine, suggesting that TCE metabolism was occurring in this tree. TCAA was only detected in the leaves of hybrid poplar and piedmont loblolly pine. Conifers took up less water over the 2-mo treatment period than hybrid poplar and grew at a slower rate. However, phytoremediation field sites may benefit from the evergreen's ability to transpire water throughout the winter months.  相似文献   
225.
In the last two years, we have seen a remarkable intensification in the response to AIDS in China. A number of organizations have joined and contributed to the efforts of the Chinese government in responding the AIDS epidemic in China. This article specifically describes the role of the United Nations in supporting and strengthening those responses.Achievements of the United Nations (UN) highlighted in the article include: strengthened leadership and political commitment to respond to AIDS; improved HIV/AIDS surveillance and information; expanded prevention efforts; improved treatment, care and support to people living with HIV and increased resources for AIDS programs. Additional roles of e., one national plan on AIDS; one national coordinating authority for AIDS; and one monitoring and evaluation system for AIDS. In addition, the UN system is expected to strengthen alignment and harmonization of activities of all international organizations and improved accountability and oversight. Remaining challenges identified include increasing awareness of AIDS and reducing stigma and discrimination; reducing vulnerability and risk behaviour among specific groups;providing improved treatment, care and support for people living with HIV; promoting stronger engagement by civil society, and; addressing the gender dimensions of AIDS.  相似文献   
226.
227.
川东南中奥陶统大沙坝组的腕足动物群   总被引:3,自引:0,他引:3  
詹仁斌 《古生物学报》2003,42(4):492-516
四川东南部长宁双河及其附近地区的中奥陶统上部大沙坝组以特殊的岩相和生物相有别于黔北的可比地层十字铺组和鄂西的牯牛潭组,地层中漂浮相化石(笔石)与底栖壳相化石(如腕足动物和三叶虫)多次交互出现,笔石动物属于上层下垂对笔石动物群(Didymograptus artus Fauna),时代为中奥陶世Darriwilian(相当于Arenig最晚期至Llanvirn)。在所采集的3300余枚化石标本中有近90%是腕足动物化石,经研究共鉴定出19属21种,分属于4目7超科15科,正形贝目和扭月贝目分别有8属,占全部属群的84%。根据属的生物地理分布,该动物群中广布型分子7属、区域性分子6属,仅限于华南的土著性分子占总量的31.6%,显示出此期华南腕足动物群具有较强的地方性色彩,进一步证实中奥陶世海洋生物强分区性的推断。该腕足动物群宜称作Saucrorthis-Glyptorthis动物群。在统计分析的基础上,识别出Saucrorthis-Glyptorthis群落,包括三个以腕足动物占优势的化石群集(association),即Glyptorthis?simplex群集、Saucrorthis obscura群集和Calyptolepta chengkouensis群集,并结合沉积岩石学以及其它共生化石门类进行群落生态分析,认为该群落所生活的环境以正常浅海砂泥质底域为主(相当于BA2-3)。与上扬子台地贵州遵义十字铺组和重庆城口厚坪组两个相近腕足动物群相比,长宁地区中奥陶世的Saucrorthis-Glyptorthis动物群更接近于厚坪组所产者。与世界上其它一些同期且具相似生态位的动物群相比,除与哈萨克斯坦南部的同期动物群比较接近外,与澳大利亚、北美、英国等地的同期动物群几乎毫无联系,指示华南中奥陶世腕足动物群可能代表一个独特的生物地理小区。  相似文献   
228.
A number of recent studies have attributed a large proportion of soil respiration (R(soil)) to recently photoassimilated carbon (C). Time lags (tau(PR)) associated with these pulses of photosynthesis and responses of R(soil) have been found on time scales of hours to weeks for different ecosystems, but most studies find evidence for tau(PR) on the order of 1-5 d. We showed that such time scales are commensurate with CO(2) diffusion time scales from the roots to the soil surface, and may thus be independent from photosynthetic pulses. To further quantify the role of physical (i.e. edaphic) and biological (i.e. vegetative) controls on such lags, we investigated tau(PR) at adjacent planted pine (PP) and hardwood (HW) forest ecosystems over six and four measurement years, respectively, using both autocorrelation analysis on automated soil surface flux measurements and their lagged cross-correlations with drivers for and surrogates of photosynthesis. Evidence for tau(PR) on the order of 1-3 d was identified in both ecosystems and using both analyses, but this lag could not be attributed to recently photoassimilated C because the same analysis yielded comparable lags at HW during leaf-off periods. Future efforts to model ecosystem C inputs and outputs in a pulse-response framework must combine measurements of transport in the physical and biological components of terrestrial ecosystems.  相似文献   
229.
Agriculture in developing countries has attracted increasing attention in international negotiations within the United Nations Framework Convention on Climate Change for both adaptation to climate change and greenhouse gas mitigation. However, there is limited understanding about potential complementarity between management practices that promote adaptation and mitigation, and limited basis to account for greenhouse gas emission reductions in this sector. The good news is that the global research community could provide the support needed to address these issues through further research linking adaptation and mitigation. In addition, a small shift in strategy by the Intergovernmental Panel on Climate Change (IPCC) and ongoing assistance from agricultural organizations could produce a framework to move the research and development from concept to reality. In turn, significant progress is possible in the near term providing the basis for UNFCCC negotiations to move beyond discussion to action for the agricultural sector in developing countries.  相似文献   
230.
Jennifer Patico 《Ethnos》2013,78(3):307-330
Public debates about international matchmaking highlight the victimization of impoverished women by western men or the self-interested instrumentalism of women who marry for visas. Meanwhile, agencies and many of their clients portray this as a linking of well-intentioned lonely hearts who just want normal family lives. A meaningful anthropological account must incorporate and move beyond both types of narratives, acknowledging that deeply felt sentiment and ‘strategic’ plans to improve one's life overlap in all kinds of social exchange, romantic or otherwise. How the relationship between self-interest and affect is understood depends upon historically specific and gendered experiences of political economy. Participants’ framings of their own and their prospective spouses’ ‘sincerity’ and ‘seriousness’ are diagnostic of structural pressures each group has experienced, which they seek to address through international marriage.  相似文献   
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