The encapsulation process in Biomphalaria glabrata experimentally infected with the metastrongylid Angiostrongylus cantonensis: enzyme histochemistry.

Enzyme histochemistry has revealed that encapsulation reactions surrounding larvae of the nematode Angiostrongylus cantonensis 4 wk after infection of the gastropod Biomphalaria glabrata are the sites of highly localized acid phosphatase and nonspecific esterase activities. Lesser amounts of alkaline phosphatase and β-glucuronidase activities also occur within such capsules, but aminopeptidase activity cannot be demonstrated. In addition, it has been ascertained that acid phosphatase activity gradually increases as the encapsulation reaction progresses during the first to the fourth week postinfection.     

Studies of the reaction products of adenosine with [Pt(NH3)3Cl]Cl and cis-Pt(NH3)2Cl2 by high performance liquid chromatography

The reaction products of adenosine with [Pt(NH₃)₃Cl]Cl or cis-Pt(NH₃)₂Cl₂ have been studied using high performance liquid chromatography and uv spectroscopy. The reaction of [Pt(NH₃)₃Cl]Cl with adenosine (pH = 7.0, Pt/base = 0.5) gives four products. Two of them, mononuclear complexes in which platinum is bound to adenosine through N(7) or N(1), comprise more than 90% of all the products. The N(1) and N(7) sites on adenosine indicate almost equal binding affinity for [Pt(NH₃)₃Cl]Cl. The reaction of cis-Pt(NH₃)₂Cl₂ with adenosine has been studied in the presence of a large excess of adenosine (Pt/base ? 0.05). The reaction gives four products. One is the monomeric 2:1 complex with cis-Pt(NH₃)₂²⁺ bound to two adenosine molecules through the N(7) site and the N(1) site, and another is the monomeric 2:1 complex with cis-Pt(NH₃)₂²⁺ bound to two adenosine molecules through the N(7) sites. cis-Pt(NH₃)₂Cl₂ is stronger affinity to the N(7) site than of adenosine to the N(1) site.     

Stimulation of HTC hepatoma cell growth in vitro by hepatic stimulator substance (HSS) : Interactions with serum, insulin, glucagon, epidermal growth factor and platelet derived growth factor

Hepatic stimulator substance (HSS), a partially purified extract of weanling or regenerating adult rat liver, is an organ-specific stimulator of liver growth in vivo and in vitro. The HTC hepatoma cell line is particularly responsive to HSS. The present experiments show that HSS will stimulate HTC cells in the complete absence of serum, although graded doses of fetal cal serum (FCS), from 0.1 to 5.0%, will increase the degree of stimulation in a dose-dependent manner. In contrast, when HSS is absent, increasing doses of FCS above 0.5% inhibit DNA synthesis. Much of this inhibition is removed by prior dialysis of the FCS and maximum enhancement of the HSS-induced stimulation occurs with only 0.1–0.5% of the dialysed FCS. Sera from older animals have less or even negative effect. Evidence is presented to show that the enhanced stimulation by HSS in the presence of serum is not due to insulin, glucagon, epidermal growth factor (EGF), or platelet derived growth factor (PDGF) and that HSS does not act via a shared receptor for one of these hormones. These experiments provide further evidence that HSS is a unique stimulator of liver growth and lend support to a model of organ-specific growth control.     

集成生态软约束机制的城市空间形态时空演变情景模拟

自然生态空间是生物栖息繁衍的场所，生物和非生物成分组成的生态系统为人类提供赖以生存的生态系统服务。新时期绿色发展战略下高质量国土空间资源配置需要科学探究生态空间约束的作用机理。以泉州市为研究区，选取水源涵养、土壤保持和生物多样性等生态系统服务为生态因子，基于有序加权平均(OWA)算法构建城市扩张的生态软约束机制。以2005年土地利用现状为起始值，综合考虑自然人文等驱动力因素，基于构建的OWA-FLUS模型对泉州市2020年和2035年土地利用时空演化动态开展多情景模拟预测。结果表明：(1)策略控制因子δ=0.000001下，OWA-FLUS模型的总体精度和Kappa系数达到95.94%和0.7742,FoM和FoM_urban比FLUS模型分别提高了4.95%和7.17%,基于提升潜力空间的MICE功效指数分别为0.059和0.102。(2)当δ值从0向1000变化时，OWA-FLUS模型的模拟精度逐渐下降。对比δ=1.0的赋权线性组合(WLC)生态约束，δ=0.000001下的OWA模拟的FoM_urban提升了5.70%。(3)2035年基准...     

Middle-class residential mobility in Mexico City: Toward a cross-cultural theory

Few social-psychological theories of intraurban residential mobility have been offered, despite a number of empirical studies of personal motives. A complete explanation of residential mobility would interrelate macroscopic economic factors with household preferences. A cross-cultural socio-psychological model is presented as a step toward a comprehensive theory. Data from an exploratory study of middle-class Mexico City residents are used to test the model. Results suggest that middle-class Mexicans decide to move because of space needs accompanying life-cycle changes, desire for home ownership, and environmental reasons. Home selection was primarily a function of availability, cost, and terms. Unlike North Americans, suburban Mexicans were uninterested in community activities and maintained close contact with relatives; central-city respondents enjoyed living in the city despite dissatisfaction with residence or neighborhood. Most would avoid the suburbs because of communication problems and distance from relatives. Results support the model and justify further testing and development.I am grateful to the University of Alabama Research Grants Committee and Center for International Studies for financial support to carry out this study.An earlier version of this paper was presented at the annual meeting of the American Sociological Society in New York, August 1976.     

生态产品价值实现率评价方法——以丽水市为例

生态产品价值实现是指在维持生态系统稳定性和完整性的前提下，通过合理开发利用生态产品，将其生态价值转化为经济效益的过程。生态产品价值实现机制包含了促进生态产品价值实现的政策、市场和技术机制。生态产品通过各种途径实现的经济价值总和称为生态产品价值实现量。生态产品价值实现量与生态产品总值(GEP)的比值为生态产品价值实现率。评估生态产品价值实现率是评判生态产品价值实现状况的基础，是评估生态产品价值实现机制是否有效运转的重要前提。提出生态产品价值实现率的概念和核算方法，以浙江省丽水市为例，在核算GEP的基础上，评估生态产品价值实现量与实现率来分析丽水市生态产品价值实现状况、问题及影响因素，提出提高生态产品价值实现率的对策建议。研究表明，丽水市2019年GEP为4110.21亿元，生态产品价值实现量为1017.49亿元，生态产品价值实现率为24.76%。丽水生态产品价值实现模式主要有市场交易和政府补偿两种模式。市场交易模式贡献了95.84%的生态产品价值实现量，是目前丽水市最有效的生态产品价值实现模式，但存在价值实现效率不均衡、对于缺乏市场或是市场机制不成熟的生态产品不适用等问题。政府补偿模式贡...     

First report of Stegomyia aegypti (= Aedes aegypti) in Mexico City,Mexico

Stegomyia aegypti (= Aedes aegypti) (Diptera: Culicidae) is a species of mosquito that is currently widespread in Mexico. Historically, the mosquito has been distributed across most tropical and subtropical areas lower than 1700 m a.s.l. Currently, populations that are found at higher altitudes in regions with cold and dry climates suggest that these conditions do not limit the colonization and population growth of S. aegypti. During a survey of mosquitoes in September 2015, larvae of S. aegypti mosquitoes were found in two different localities in Mexico City, which is located at about 2250 m a.s.l. Mexico City is the most populous city in Mexico and has inefficient drainage and water supply systems. These factors may result in the provision of numerous larval breeding sites. Mosquito monitoring and surveillance are now priorities for the city.     

Diet and sperm quality: Nutrients,foods and dietary patterns

Human semen quality has declined worldwide in the last 40 years, by some accounts as much as 50–60%, causing serious concerns and implications for human fertility. Even though it has been shown to be a worldwide problem, this decrease is more pronounced in developed and industrialized countries, pointing to changes in modifiable lifestyle factors (e.g. unhealthy diets, lifestyles, and pollution) as the main causes. Studies investigating the relation between diet and semen quality can be classified into three groups; studies assessing the association between semen quality and 1) nutrients, dietary supplements and antioxidants, 2) food, and 3) dietary patterns. The present narrative review provides a wide-ranging vision of the positive associations and effects of diet on sperm quality. Although the picture of the relationship between diet and sperm quality and fertility is far from complete, a number of broad conclusions have emerged. First, increased intake of selenium and zinc, omega-3 (ω-3) fatty acids, CoenzymeQ10 (CoQ10) and carnitine supplements have been positively related to sperm quality. In terms of food groups, vegetables, fruits, nuts and whole cereals, all rich in fiber and antioxidants, and fish, seafood, shellfish, poultry, and low-fat dairy products have been positively associated with sperm quality. Finally, adherence to healthy dietary patterns is positively associated with sperm concentration and sperm motility.     

水生态文明城市建设对城市水生态承载力的影响——以武汉市为例

城市水生态承载力能较好反映水资源-水环境-水生态-经济社会复合系统间多要素互馈关系，水生态文明城市建设对城市水生态系统具有多方面影响，对城市水生态承载力在水生态文明城市建设前后的变化进行定量研究具有重要意义。以城市"社会-经济-自然"复合生态理论为指导，充分考虑人类活动与城市水生态系统的响应关系，基于DPSIR框架构建城市水生态承载力评价指标体系，以水生态文明建设试点城市武汉市为例，综合运用熵权法、TOPSIS和障碍度诊断模型等方法，分析2008-2019年武汉市水生态承载力的变化趋势和影响因素。结果表明，水生态文明城市试点建设期间（2015-2017年）的水生态承载力平均水平（0.552）明显高于建设前（0.361）和建设后（0.438），建设成果主要体现在压力和影响指标的改善以及响应指标的大幅度提升上。阻碍武汉市水生态承载力提升的主要指标为生态环境状况指数、建成区绿化覆盖率、农田灌溉亩均用水量、酸雨量和饮用水源地水质达标率。根据评价结果提出水城共生共荣发展模式、引导产业结构转型等提升武汉市水生态承载力的建议。