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651.
应急物资储备库是应急救援的重要载体,储备库选址是否科学合理决定着整个应急公共服务体系的成效,而传统遗传算法在研究储备库选址与物资调配相结合的问题上存在局限性。针对这一问题,从需求点及应急设施服务质量视角构建基于覆盖满意度和经济性的应急设施选址与物资调配优化模型,并根据模型设计自适应遗传算法(AGA),结合储备库实际情况采取具有方向性的初始群体生成法提高搜索速度,设计自适应交叉与变异算子使AGA能够在进化速度与解的质量之间进行权衡,并获得全局最优解。结果表明,该算法能跳出局部最优从而获得最优的选址-分配方案,可为应急管理部门和决策机构的应急设施选址规划及应急物资分配提供理论依据和决策参考。 相似文献
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Chinese pine, Pinus tabulaeformis Carr., a species that ranges broadly across northeastern to southwestern China, plays a vital role in the maintenance of
the structure and function of these ecosystems. In this study, we examined the genetic diversity of five widespread populations
in Shanxi Plateau, the distribution center of Chinese pine, using 15 random amplified polymorphic DNA (RAPD) primers and five
inter simple sequence repeat (ISSR) primers in 140 individual tree samples. Similar genetic differentiation results were obtained
from the data of RAPD and ISSR. Based on the two sets of data, Nei’s genetic diversity was 0.2842 and 0.3078 and Shannon’s
indices of diversity were 0.4332 and 0.4468. Genetic diversity at the species level was found high relative to that for other
genera of Pinaceae. The greatest diversity was observed in the Lingkong Mountain population (0.3860), while the lowest was recorded in the Luya
Mountain population (0.3352), most likely as a result of natural adaptation and anthropogenic perturbation. The relative magnitude
of differentiation among populations (G
ST) was 0.1491 and 0.1356, respectively, implying that most genetic variation was within the populations (∼0.8509), rather than
among populations.
Published in Russian in Ekologiya, 2008, No. 1, pp. 36–42.
The article was translated by the authors. 相似文献
656.
STEVEN R. EWING‡ RUEDI G. NAGER MALCOLM A. C. NICOLL† AURELIEN AUMJAUD‡§§ CARL G. JONES‡§ LUKAS F. KELLER†† 《Conservation biology》2008,22(2):395-404
Abstract: Many populations have recovered from severe bottlenecks either naturally or through intensive conservation management. In the past, however, few conservation programs have monitored the genetic health of recovering populations. We conducted a conservation genetic assessment of a small, reintroduced population of Mauritius Kestrel ( Falco punctatus ) to determine whether genetic deterioration has occurred since its reintroduction. We used pedigree analysis that partially accounted for individuals of unknown origin to document that (1) inbreeding occurred frequently (2.6% increase per generation; N eI = 18.9), (2) 25% of breeding pairs were composed of either closely or moderately related individuals, (3) genetic diversity has been lost from the population (1.6% loss per generation; N eV = 32.1) less rapidly than the corresponding increase in inbreeding, and (4) ignoring the contribution of unknown individuals to a pedigree will bias the metrics derived from that pedigree, ultimately obscuring the prevailing genetic dynamics. The rates of inbreeding and loss of genetic variation in the subpopulation of Mauritius Kestrel we examined were extreme and among the highest yet documented in a wild vertebrate population. Thus, genetic deterioration may affect this population's long-term viability. Remedial conservation strategies are needed to reduce the impact of inbreeding and loss of genetic variation in this species. We suggest that schemes to monitor genetic variation after reintroduction should be an integral component of endangered species recovery programs. 相似文献
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Prenatal diagnosis of Gaucher disease, the most prevalent glycolipid storage disease, is based on a reliable enzyme assay of cells from amniocentesis or chorionic villous samples. However, this method cannot differentiate among the various forms of the disease. This report details four cases of prenatal diagnosis of Gaucher disease, three of which predate the use of molecular diagnosis. DNA mutation analysis to determine the genotype was predictive of the phenotypic status of the fetus and conformed to the genotype of an affected proband where available. 相似文献