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51.
In a fetus with ventricular extrasystoles a congenital aneurysm of the left ventricle was diagnosed prenatally. At 32 weeks of gestation, echocardiography showed a large apical left ventricular aneurysm with a thin, hypokinetic wall. Congestive heart failure did not occur. Prenatal and postnatal examinations did not detect the aetiology of the aneurysm, but excluded the majority of possible causes. The 2-year-old child is now asymptomatic and normally developed. Neither medication nor surgical treatment have been necessary, except for antithrombotic prophylaxis with low-dose aspirin.  相似文献   
52.
Vector-borne diseases are feared to extend their range in a future where global warming has occurred. There is considerable concern about scourges such as malaria re-invading currently temperate regions and reaching into higher altitudes in Africa. In this paper we examine the various factors thought to determine potential infectivity of malaria, and its actual outbreak in the context of a dynamic integrated assessment model. We quantify: (i) the role of demographics in placing a larger population in harms way; (ii) the role of climate change in increasing the potential geographic range and severity of the risk of infection; and (iii) the role of economic and social development in limiting the occurrence of malaria. We then explore the climate and economic implications of various climate policies in their effectiveness to limit potential infectivity of malaria. In illustration of these issues we present the climate-related and economics-related impacts of unilateral CO2 control by OECD on incidence of malaria in non-OECD nations. The model presented here, although highly stylized in its representation of socio-economic factors, provides strong evidence of the role of socio-economic factors in determination of malaria incidence. The case study offers insights into unintended adverse consequences of well-meaning climate policies. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
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我国秦至清末的疫病灾害研究   总被引:4,自引:0,他引:4  
杨俭  潘凤英 《灾害学》1994,9(3):76-81
本文根据《中国历代天灾人祸表》中疫病的文字记载,统计出各个历史时期疫病发生时间(季节)、频数及其与旱、涝(水)、地震、战争等灾难事件的关系,进而推测历史时期疫病所包含的急性传染病。统计发生周期,证实疫病周期与太阳、太阳系活动规律有明显的相关性。  相似文献   
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Humans influence tropical rainforest animals directly via exploitation and indirectly via habitat disturbance. Bushmeat hunting and logging occur extensively in tropical forests and have large effects on particular species. But how they alter animal diversity across landscape scales and whether their impacts are correlated across species remain less known. We used spatially widespread measurements of mammal occurrence across Malaysian Borneo and recently developed multispecies hierarchical models to assess the species richness of medium‐ to large‐bodied terrestrial mammals while accounting for imperfect detection of all species. Hunting was associated with 31% lower species richness. Moreover, hunting remained high even where richness was very low, highlighting that hunting pressure persisted even in chronically overhunted areas. Newly logged sites had 11% lower species richness than unlogged sites, but sites logged >10 years previously had richness levels similar to those in old‐growth forest. Hunting was a more serious long‐term threat than logging for 91% of primate and ungulate species. Hunting and logging impacts across species were not correlated across taxa. Negative impacts of hunting were the greatest for common mammalian species, but commonness versus rarity was not related to species‐specific impacts of logging. Direct human impacts appeared highly persistent and lead to defaunation of certain areas. These impacts were particularly severe for species of ecological importance as seed dispersers and herbivores. Indirect impacts were also strong but appeared to attenuate more rapidly than previously thought. The lack of correlation between direct and indirect impacts across species highlights that multifaceted conservation strategies may be needed for mammal conservation in tropical rainforests, Earth's most biodiverse ecosystems. Correlación y Persistencia de los Impactos de la Caza y la Tala sobre los Mamíferos de los Bosques Tropicales  相似文献   
57.
通风设施防护效果评价指标研究   总被引:1,自引:0,他引:1  
当前我国职业病危害形势严峻,尘毒危害是职业病危害防治的重点,而通风设施是预防和控制尘毒危害的重要工程防护措施。阐述了通风设施在职业病危害预防与控制方面的作用,对我国企业现行的新风量、全面通风量、通风换气次数和职业接触限值等通风设施防护效果评价指标、国外普遍采用的控制风速防护效果评价指标以及目前有些机构使用的捕集效率评价指标进行了分析和讨论,对新风量、通风量和通风换气次数在职业病危害预评价和控制效果中的应用进行了研究,并得出了我国需建立健全通风设施防护效果评价指标和评估方法的结论。  相似文献   
58.
沙尘暴对呼吸及循环系统疾病日门诊量的影响   总被引:10,自引:1,他引:10       下载免费PDF全文
对沙尘天气频发区甘肃省武威市的7所大、中型医院在2004、2005年沙尘天气高发时段(3月1日~5月31日)的呼吸系统和循环系统每日门诊人数进行了调查,采用半参数广义相加模型(GAM),在排除了医院日门诊量的长期趋势、大气污染因素、气象因素、日历效应等因素之后,分别对每年进行分析.结果表明,沙尘暴和扬沙天气与呼吸、循环系统疾病日门诊人数的增加有联系,且均表现为滞后效应,其影响程度为沙尘暴大于扬沙天气,沙尘暴和扬沙天气对健康的影响因不同年份而不同,表明沙尘天气对健康的影响受多种因素的影响.沙尘暴对健康的影响有性别差异.  相似文献   
59.
尘肺危害的神经网络评价及预测研究   总被引:2,自引:2,他引:0  
尘肺发病率与其所受影响因素—粉尘毒性、粉尘浓度及接尘时间等之间的关系 ,呈非线性。笔者引入神经网络 ,建立了从影响因素到发病率的算法模型 ,并开发了相应的软件(PHAF)。该软件在学习样本数据基础上 ,可以对尘肺危害进行评价和预测  相似文献   
60.
生物资源在减轻植物病害中的作用、潜力及其利用对策   总被引:2,自引:0,他引:2  
论述了生物资源在减轻植物病害灾害和促进农业可持续发展中所具有的良好生态效益和经济效益 ,以及巨大开发潜力 ,讨论并提出了减轻植物病害中生物资源利用所面临的问题和应采取的对策  相似文献   
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