Preserving Population Allele Frequencies in Ex Situ Conservation Programs

Abstract: Optimization of contributions of parents to progeny by minimizing the average coancestry of the progeny is an effective strategy for maintaining genetic diversity in ex situ conservation programs, but its application on the basis of molecular markers has the negative collateral effect of homogenizing the allelic frequencies at each locus. Because one of the objectives of a conservation program is to preserve the genetic composition of the original endangered population, we devised a method in which markers are used to maintain the allele frequency distribution at each locus as closely as possible to that of the native population. Contributions of parents were obtained so as to minimize changes in allele frequency for a set of molecular markers in a population of reduced size. We used computer simulations, under a range of scenarios, to assess the effectiveness of the method in comparison with methods in which contributions of minimum coancestry are sought, either making use of molecular markers or genealogical information. Our simulations indicated that the proposed method effectively maintained the original distribution of allele frequencies, particularly under strong linkage, and maintained acceptable levels of genetic diversity in the population. Nevertheless, contributions of minimum coancestry determined from pedigree information but ignoring the genealogy previous to the conservation program, was the most effective method for maintaining allelic frequencies in realistic situations.     

EFFECTS OF SIMULATED CLOUD SEEDING ON STREAMFLOW OF SELECTED WATERSHEDS IN PENNSYLVANIA1

A mathematical model was developed to simulate the hydrologic behavior of five small watersheds in central Pennsylvania. Continuous hydrographs for the 6-month period, April to September 1964, were simulated. Synthesized rainfall cycles consisting of increasing rainfall by 10, 20, and 30 percent to simulate the effects of cloud seeding were processed through the watershed model to determine the effects on low flow augmentation. Other rainfall cycles used consisted of increasing every third storm by 30 percent and of developing a rainfall cycle by processing daily radiosonde data through a mathematical cumulus cloud model to obtain a prediction of rainfall following seeding. A comparison of actual and predicted hydrographs indicated that simulated cloud seeding resulted in significant monthly and seasonal water yields. In general, the results of the study appear to indicate that on a theoretical basis cloud seeding would be a feasible method of augmenting low stream-flow during the summer months on watersheds in the northern Appalachian region.     

A SELF-VERIFYING HYBRID COMPUTER MODEL OF RIVER-BASIN HYDROLOGY1

ABSTRACT. As demands upon available water supplies increase, there is an accompanying increase in the need to assess the downstream consequences resulting from changes at specific locations within a hydrologic system. The problem is approached in this study by hybrid computer simulation of the hydrologic system. Modeling concepts are based upon the development of basic relationships which describe the various hydrologic processes. Within a system these relationships are linked by the continuity-of-mass principle. Spatial resolution is achieved by considering the modeled areas as a series of subbasins. The time increment adopted for the model is one month, so that time varying quantities are expressed in terms of mean monthly values. The model is general in nature and is applied to a particular hydrologic system through a programmed verification procedure whereby model coefficients are evaluated for the particular system. In this study the model is applied to the Bear River basin of western Wyoming, southern Idaho, and northern Utah. Comparisons between observed and computed outflow hydrographs show good agreement. The utility of the model is demonstrated by predicting the effects of various possible water resource management alternatives. The verified hybrid computer program can be digitized for application to the digital computer.     

煤与瓦斯突出一般规律定性定量分析研究

通过大量数据统计 ,定性和定量分析了煤与瓦斯突出与开采深度、巷道类型、地质构造、作业方式、突出预兆、煤层厚度等因素之间关系 ,总结出煤与瓦斯突出灾害的一般规律 ,这对提高突出矿井防突技术水平和安全管理 ,具有重要的指导意义。     

CHLOROPHYLL-BIOMASS-NUTRIENT RELATIONSHIPS FOR NATURAL ASSEMBLAGES OF FLORIDA PHYTOPLANKTON1

Parallel determination of phytoplankton biomass and chlorophyll a concentration were made on spring and summer phytoplankton samples collected from 165 Florida lakes. There was a significant correlation between chlorophyll a concentration and phytoplankton biomass (r=0.80; P < 0.01). Chlorophyll content per unit phytoplankton biomass ranged over two orders of magnitude. Nitrogen seemed to be a major factor influencing the chlorophyll content of Florida algae. Multiple regression analyses indicated that phytoplankton biomass was dependent on both the total phosphorus and total nitrogen concentration. Nutrient-phytoplankton and Secchi-phytoplankton relationships for the Florida lakes had higher coefficients of determination if chlorophyll a concentrations rather than phytoplankton biomass data were used in regression analyses.     

Changes in interacting species with disturbance

Human-influenced changes in the diversity and abundance of native wildlife in a southern boreal forest area, which became a national park in 1975, are used to develop working hypotheses for predicting and subsequently measuring the effects of disturbance or restoration programs on groups of interacting species. Changes from presettlement conditions began with early 1900 hunting, which eliminated woodland caribou (Rangifer tarandus) and elk (Cervus elaphus), and reduced moose (Alces alces) to the low numbers which still persist. Increases in white-tailed deer (Odocoileus virginianus), as these other cervid species became less abundant or absent, provided enough alternative food to sustain the system's carnivores until plant succession on previously burned or logged areas also caused deer to decline. With increased competition for reduced food, carnivore species also became less abundant or absent and overexploited some prey populations. The abilities of interacting species to maintain dynamically stable populations or persist varied with their different capacities to compensate for increased exploitation or competition. These relationships suggested a possible solution to the problem of predicting the stability of populations in disturbed systems. For the 1976–1985 period, a hypothesis that the increased protection of wildlife from exploitation in a national park would restore a more diverse, abundant, and productive fauna had to be rejected.     

南海市耕地数量变化驱动力的定量分析

分析了南海市耕地数量变化的特点，并用定性与定量相结合的方法进一步探讨了耕地数量变化的驱动力。结果表明，南海市耕地数量的变化与珠江三角洲耕地数量变化的时间基本一致且与经济发展同步。经济发展、人口增长、基础设施建设及农业结构调整是耕地数量变化的主要驱动力。     

Polyoxometalates for photocatalytic degradation of aqueous dyestuff solutions and quantitative structure–property relationship study on photolysis rate constants

Polyoxometalate, K₆TiW₁₁O₃₉Sn·7H₂O (TiW₁₁Sn), was synthesized and characterized. TiW₁₁Sn and K₆ZrW₁₁O₃₉Sn·12H₂O (ZrW₁₁Sn) were evaluated for their photocatalytic degradation of triarylmethane (brilliant green and acid blue 9), bisazo (C.I. reactive black 5), and monoazo dyestuffs (C.I. reactive red 24, C.I. reactive red 194, and C.I. reactive orange 5) with natural sunlight in homogeneous aqueous solutions. TiW₁₁Sn and ZrW₁₁Sn effectively and photocatalytically decolorized the dyestuffs. The TiW₁₁Sn- and ZrW₁₁Sn-mediated photocatalytic degradation of the dyestuffs involved a pseudo-first-order reaction and was modeled by Langmuir–Hinshelwood-type kinetics. The observed pseudo-first-order rate constants (K^/) of triarylmethane dyestuffs were generally bigger than that of the azo dyestuffs. Quantitative structure–property relationship models of the K^/ of the dyestuffs were developed using partial least-square regression. The cumulative variance of the dependent variable explained by the partial least-square components was > 0.753 for each optimal model. This value indicated that the model had good predictive ability and robustness. The K^/ values of the dyestuffs were related to the energy of the lowest unoccupied molecular orbital, and the most positive net atomic charges on a sulfur atom of dyestuffs. The linear correlation coefficients between the predicted and experimental values were all > 0.9950.     

The social consequences of a natural/technological disaster: evidence from Louisiana and Mississippi

Disaster scholarship shows that people’s relationships stay the same or improve after natural disasters and become worse after technological, or human-induced, events. Using the case of Katrina, this research explores what happens to people’s relationships after a disaster that began with a catastrophic natural event and was followed by numerous failures in the way human institutions responded to the event. Through an analysis of survey data collected in devastated areas of Louisiana and Mississippi in 2008, this study tests how consequences of both natural (damage to the home and having to leave the home) and technological events (distrust in government, stress, concern about toxic exposure, and pursuing litigation) affect people’s relationships with family members and community groups. Damage to the home, distrust in government, and the pursuit of litigation lead to declines in people’s relationships. These experiences are more likely to change intimate relationships (with family) than relationships in the broader community. The relevance that these findings have for creating better social justice outcomes after future disasters is discussed.     

随机性混合数据评价技术的方法研究

在城市和环境规划等方案评价中,如何综合利用定性和定量信息是人们较为关注的问题。本文首先将方案评价中常见的定性信息分为三大类,并用数学式来描述各类定性信息,在此基础上,运用随机处理的方法对定性信息进行处理后与定量信息进行综合,以求得各个方案的优劣排序概率,并由此概率确定最优方案。这种方法克服了以往同类方法只能利用定性信息中的排序信息的缺点,从而使得方案评价更客观。最后,本文给出了方法应用的实例。