硒元素与健康

硒是人类生命活动所必需的微量元素.文章从硒的存在状态和分布特点,以及硒的生物效应与生命健康的关系等方面,对硒与人类生命活动的影响进行了探讨,以达到对硒元素较全面的认识.     

Chemical endemic diseases and their impact on population in china

This paper deals with some endemic diseases related to selenium, iodine and fluoride in eco-environment. Keshan disease and Kaschin-Beck disease are associated with low selenium, they mainly occur in a belt zone across China ranging from North-East to South-West. Selenium contents in food grains and human hair from the disease affected areas are usually below 0.020ppm and 0.20ppm respectively. The endemic goitre caused by iodine deficiency distributes extensively in China, mainly in mountainous and hilly districts, swamp and peat areas, some sand soil and limestone areas. Also there is another kind of endemic goitre which caused by iodine excess in interior and coast areas. Endemic cretinism usually occurs in the endemic goitre seriously affected areas. Endemic fluorosis is also widely distributed in China, but mainly occurs in dry or semi-dry areas of north China. The fluoride sources for causing endemic fluorisis are drinking water and food grains polluted by coal smoke in the backing process of maize     

Geochemical Environment and Health Problems in China

China is a very large developing country covering vast territories and having a complex natural environment. It has an enormous population and numerous endemic diseases. The total population of China is 14 x 10(8) of which 3 x 10(3) live in endemic disease-affected areas and 0.48 x 10(3) suffer from these diseases. The distribution of the endemic diseases has obvious geographical characteristics. Among the most harmful and widely distributed of the endemic diseases are Kaschin-Beck disease, Keshan disease, iodine deficiency, endemic fluorosis and hepatic carcinoma. The geographical environments have a close relationship to endemic diseases and are influenced by climate, geology, landform, soil, food and drinking water. Drinking water is the key issue, since polluted water, or water lacking in or having an excess of certain minerals and elements, as well as water containing certain organic components, has been shown to be harmful to human health. Research has shown that some diseases can be reduced or eliminated by paying attention to the way drinking water is obtained, as well as by improving the nutritional values of the food by eliminating negative components. Fifty years of research has already gone into this subject and there is still much research to be done. This paper puts forth a model of health problems related to geographical environment and the importance of continued research in this field.     

湖南省特有植物的分布

湖南省特有植物共计235种(含种下等级;下同),归110属52科,其中蕨类植物25种,裸子植物3种,被子植物207种(双子叶植物和单子叶植物各计125和82种),主要集中于Theaceae,Rosaceae,Dryopteridaceae,Urticaceae,Ericacaeae,Gesneriaceaea,Labiatae(=Lamiaceae)和Gramineae(=Poaceae)等8科,共计155种,占全省总特有种数的65.96%.湖南特有植物所归的属的分布区类型以北温带,热带亚洲,泛热带及中国特有成分为主,分别占总数的20.00%,19.09%,13.64%和13.64%.从水平分布上看,湖南省特有植物主要分布于西北部,计77种,占全省总特有种数的32 17%;其次是西南部与南部,各有51和50种,分别占全省总特有种数的21.70%和21.28%,从垂直分布上看,它们主要分布于中山地带(海拔800-1 600m),计108种,占全省总特有种数的45.80%;其次是低山地带(海拔300-800m),计84种,占全省总特有种数的35.88%。     

喀斯特特有植物罗甸小米核桃幼苗对光照强度的可塑性响应

研究光照强度对1年生喀斯特特有植物罗甸小米核桃幼苗可塑性的影响,探讨其在个体定居初期如何响应不同光照强度的变化及其生态适应策略.设置约为自然光100％、75％、50％和25％的光照强度处理材料,4个月后收获,比较分析罗甸小米核桃幼苗的形态、生物量分配和生理性状在不同光照强度处理下的差异,并对可塑性指标进行综合评价.结果...     

A study on "selenium-health" database in China

A database for "Se and health" has been established using DATA-TRIEVE data management system on a VAX-11/780 computer. Over 5000 pieces of information including 300 kinds of samples from 28 provinces in China were stored. The information relates to endemk diseases such as Keshan disease, Kaschin-Beck disease, Se-poison disease, cancers, heart disease and so on. The database can be accessed through keywords: samples, province, county, analytical method and the Se-content values can be obtained in tabulated form. The output includes primary statistics of the retrieved data sets. A multi-variable statistic program package featuring in pattern recognition is attached to the system.     

Impact and Dynamics of Disease in Species Threatened by the Amphibian Chytrid Fungus, Batrachochytrium dendrobatidis

Abstract:  Estimating disease-associated mortality and transmission processes is difficult in free-ranging wildlife but important for understanding disease impacts and dynamics and for informing management decisions. In a capture–mark–recapture study, we used a PCR-based diagnostic test in combination with multistate models to provide the first estimates of disease-associated mortality and detection, infection, and recovery rates for frogs endemically infected with the chytrid fungus Batrachochytrium dendrobatidis (Bd), which causes the pandemic amphibian disease chytridiomycosis. We found that endemic chytridiomycosis was associated with a substantial reduction (approximately 38%) in apparent monthly survival of the threatened rainforest treefrog Litoria pearsoniana despite a long period of coexistence (approximately 30 years); detection rate was not influenced by disease status; improved recovery and reduced infection rates correlated with decreased prevalence, which occurred when temperatures increased; and incorporating changes in individuals' infection status through time with multistate models increased effect size and support (98.6% vs. 71% of total support) for the presence of disease-associated mortality when compared with a Cormack–Jolly–Seber model in which infection status was restricted to the time of first capture. Our results indicate that amphibian populations can face significant ongoing pressure from chytridiomycosis long after epidemics associated with initial Bd invasions subside, an important consideration for the long-term conservation of many amphibian species worldwide. Our findings also improve confidence in estimates of disease prevalence in wild amphibians and provide a general framework for estimating parameters in epidemiological models for chytridiomycosis, an important step toward better understanding and management of this disease.     

长江上游合江江段鱼类早期资源与向家坝水库生态调度效果初步研究

合江江段是长江上游干流保持河流生境、适宜喜流水性鱼类栖息的重要江段.为了掌握合江江段鱼类早期资源动态,分析向家坝水库生态调度的效果,于2020年向家坝水库生态调度前后,开展了鱼类早期资源逐日监测.研究期间,共采集到鱼类早期资源5目10科38种(属),其中仔鱼29种(属)、鱼卵19种(属),包括特有鱼类6种.广适应性和喜...     

云南地区中国种子植物特有属的研究

物种特有现象的研究具有重要的区系地理学和保护生物学意义。利用大尺度的植物物种分布信息,探讨了云南地区中国种子植物特有属的科、属组成,区系性质及其地理分布格局。结果表明,云南地区拥有中国种子植物特有属125属,分属于59科,共含种子植物246种,是中国种子植物特有属的重要分布地区之一。含特有属较多的科主要为菊科Compositae、苦苣苔科Gesnefiaceae、伞形科Umbelliferae、禾本科Gramineae和唇形科Labiatae。从各属所包含的物种数来看,单型属占主体地位。根据科的分布区类型构成,云南地区中国种子植物特有属主要起源于热带地区。从属的生活型构成来看,主要以草本植物属为主,而木本植物属所占比重相对较小,暗示着研究区域内特有属的区系兼有年轻成分和古老成分,但以年轻成分为主。从空间分布格局来看,特有属主要分布在“田中线”以东地区。与过去的研究结果不同,我们发现云南地区拥有3个重要的特有属分布中心和3个次级分布中心。