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1.
反社会行为倾向的发展不仅受家庭、社会、环境因素的影响,也受基因因素的影响,如单胺氧化酶基因、5-HT转运蛋白基因、多巴胺D2受体基因等.研究发现,特定基因因素和环境因素会以交互作用的方式影响个体的反社会行为.本文对近些年来基因环境交互作用影响的行为研究和脑成像研究做了一个简要综述,并对今后的研究做出了积极的展望.  相似文献   

2.
精神分裂症及其疗效与受体基因的相关性   总被引:1,自引:0,他引:1  
探讨了近年有关精神分裂症的病因和疗效 ,及其受体基因之间的关系 .精神分裂症的遗传倾向提示其部分病因是在基因上 ,多巴胺、5 HT(5羟色胺 )等假说是解释精神分裂症病因机制的主要生化假说 ,这两方面提示精神分裂症与D、5 HT等受体基因可能存在重要联系  相似文献   

3.
植物的衰老   总被引:1,自引:0,他引:1  
衰老是植物发育的一个重要组成部分,是受基因调控的程序性过程。在衰老过程中,植物细胞在细胞结构、细胞功能、新陈代谢和基因表达等方面经历一系列的协调变化,一些环境因素和内在因素影响着植物的衰老。解释植物衰老的学说主要有营养耗尽假说和衰老激素假说。  相似文献   

4.
环境因素调控对兰花栽培技术的改进和创新有着非常重要的意义, 是兰花资源保护与开发研究领域的一个重要组成部分.兰花的生长与生理受环境温度、相对湿度、光照、栽培基质、施肥等因素的影响.本文综述了国内外环境因素与兰花生长机理之间的关系.今后的研究应集中在以下方面:(1)探讨和比较研究不同环境因素多梯度兰花的生长与生理, 逐步扩大生长与生理研究的范围;(2)研究多种兰花生长机理的共性, 进一步加强特性的研究;(3) 进行环境因素与兰花生长机理的多学科合作研究, 将为兰花资源保护与开发做出新的贡献.  相似文献   

5.
地下水位动态预测对滑坡稳定性评价具有关键作用.滑坡地下水位演化过程是一个受水文地质条件控制,并受降雨、库水和气温等多种影响因素综合作用而发展演化的非线性动力系统,地下水位与其影响因素之间存在非线性响应关系.以三峡库区白家包滑坡地下水位监测数据为例,在深入分析滑坡地下水位变化特征及其与影响因素响应关系的基础上,利用非线性智能遗传算法和支持向量机建立进化支持向量机耦合模型,并对地下水位进行预测,其预测结果的均方差和相关系数的平方分别为0.013和0.929,说明预测结果与实测值较吻合.选择神经网络模型进行对比,耦合模型的均方差小154%,而相关系数的平方大10%.综合表明进化支持向量机耦合模型具有较好的拟合和泛化能力,是一种行之有效的滑坡地下水位预测方法.  相似文献   

6.
根据犏牛雄性不育的研究结果,提出了犏牛雄性不育的多基因遗传不平衡假说.假说认为,不育性是受多基因控制的,牦牛和普通牛由于在多个基因位点上的遗传差异而使犏牛的基因平衡失调,导致不育.最后对该假说的部分证据进行了讨论和分析  相似文献   

7.
哺乳动物胚胎发育是一个受复杂信号通路严格调控的过程,同时受遗传和环境因素等多种因素影响.由体外培养环境破坏活性氧ROS平衡所引起的氧化应激反应被认为是影响体外胚胎发育的重要因素之一,但活性氧影响胚胎的机制仍有待研究.本研究首先观察了叠氮化合物2,2'-偶氮二(2-脒基丙烷)盐酸盐AAPH[2,2-Azobis(2-Amidinopropane)dihydrochloride]处理后对胚胎发育的影响,检测了胚胎的活性氧水平、线粒体膜电位和细胞凋亡情况,同时检测了合子基因组激活相关基因的表达变化,针对活性氧诱导剂AAPH影响小鼠早期胚胎发育的分子机制进行研究.结果表明,AAPH能够提高小鼠胚胎的活性氧水平,影响胚胎发育率,AAPH的作用呈现剂量依赖性,这种影响是通过降低线粒体的膜电位,进而促发细胞凋亡.同时,抑制合子基因组激活相关基因Zscan4d、eIF-1A、Hspa1b、H2afz的表达.本研究探讨了活性氧影响早期胚胎发育过程的机制,为哺乳动物体外受精培养体系的优化提供了依据.  相似文献   

8.
城市可持续发展系统是一个复杂的非线性系统,环境因素对城市的可持续发展程度有较大的影响.该文尝试建立一套环境因素指标体系以衡量城市可持续发展受环境因素的影响情况,并借助于神经网络的非线性、自学习等功能对受影响情况作出判断.  相似文献   

9.
在植物的某些组织中存在富含甘氨酸的蛋白质,根据GRPs中甘氨酸的含量和氨基酸的种类、数目及排列顺序的差异,推测植物的GRPs存在3种类型,这些GRPs在植物的生长发育及植物防御过程中起重要作用,已有大量的GRP基因被分离鉴定,并对一些GRP基因的启动子进行了分析,GRPs基因的表达受植物发育的调节,具有组织或器官特异性,很多GRP基因的表达还受环境因素的影响。  相似文献   

10.
应激(stress)是指机体在受到强烈的内外环境因素的刺激时所出现的非特异性全身反应.从进化的角度来看,机体为了能应对在生长过程中遇到不可避免的内外环境因素的刺激,需要产生相应的反应,从而才能在变动的环境中维持机体的适应能力.研究应激对于理解应激对机体的影响非常重要,随着对应激研究的深入,应激动物模型成为研究的基本工具,其中束缚应激作为一种非损伤性刺激,能够较好地模拟人类生活中“无法控制”的拥挤、挫折等生活状态,既与人类产生应激及其导致的心身性疾病过程相似,又能够适应应激状态由急性转入慢性的发展趋势.因此,束缚应激已经引起研究者的广泛关注并逐渐成为应激研究中的热点之一.近年的研究使人们对束缚应激有了更为深入的了解,但是束缚应激对机体的影响及其作用机理仍有诸多不清楚的地方.本文将对近年来国内外有关束缚应激研究的进展(主要从分类、方法、对机体的影响及其作用机制等方面)进行综述.  相似文献   

11.
Dissecting the architecture of a quantitative trait locus in yeast   总被引:28,自引:0,他引:28  
Most phenotypic diversity in natural populations is characterized by differences in degree rather than in kind. Identification of the actual genes underlying these quantitative traits has proved difficult. As a result, little is known about their genetic architecture. The failures are thought to be due to the different contributions of many underlying genes to the phenotype and the ability of different combinations of genes and environmental factors to produce similar phenotypes. This study combined genome-wide mapping and a new genetic technique named reciprocal-hemizygosity analysis to achieve the complete dissection of a quantitative trait locus (QTL) in Saccharomyces cerevisiae. A QTL architecture was uncovered that was more complex than expected. Functional linkages both in cis and in trans were found between three tightly linked quantitative trait genes that are neither necessary nor sufficient in isolation. This arrangement of alleles explains heterosis (hybrid vigour), the increased fitness of the heterozygote compared with homozygotes. It also demonstrates a deficiency in current approaches to QTL dissection with implications extending to traits in other organisms, including human genetic diseases.  相似文献   

12.
The term "neurodevelopmental disorder" broadly encompasses conditions thought to arise early in development and includes schizophrenia, bipolar disorder and autism among others. These conditions share a number of genetic and environmental risk factors postulated to lead to common difficulties in socio-emotional processing, communication and cognitive function. The alternative position is that, while the same traits are affected across these conditions, the nature or direction in which they are modified may be distinct. MRI studies provide a rapidly expanding and rich database which we propose can be used to contribute to this debate. Anatomical likelihood estimation (ALE) is a method of meta-analysis applied to voxel-based MRI studies. We have adapted this method to explore the extent to which schizophrenia and bipolar disorder and schizophrenia and autism share a common brain structural phenotype. We will review this work here and discuss whether there is sufficient other evidence to justify a common framework for further research into the inter-relatedness of such conditions.  相似文献   

13.
攻击的遗传学基础研究   总被引:2,自引:0,他引:2  
同人类的许多行为一样,攻击具有遗传学基础.随着行为遗传学的兴起,研究者主要运用双生子研究与收养研究模式对攻击的遗传机制进行了大量研究,发现攻击,特别是严重的或终生持续的攻击或反社会行为具有明显遗传性;遗传与环境在攻击发生发展中具有交互作用,消极环境因素在高攻击性遗传危险的个体身上效应更大,攻击或暴力遗传危险使处于不利环境中的个体更可能出现攻击与反社会行为.这些研究发现对攻击干预具有重要实际价值.本文最后提出了在理解和解释遗传对人类攻击的作用时需要注意的几个问题.  相似文献   

14.
生态环境恶化是当前人类所面临的共同问题,我国的生态环境现状也不容乐观,人口迅速增长是环境恶化的主因.有效地控制人口增长,合理地利用自然资源,积极地建设当代条件下的生态环境类型区,才能从根本上改善我国的环境状况,提高环境的质量.  相似文献   

15.
Melbourne BA  Hastings A 《Nature》2008,454(7200):100-103
Extinction risk in natural populations depends on stochastic factors that affect individuals, and is estimated by incorporating such factors into stochastic models. Stochasticity can be divided into four categories, which include the probabilistic nature of birth and death at the level of individuals (demographic stochasticity), variation in population-level birth and death rates among times or locations (environmental stochasticity), the sex of individuals and variation in vital rates among individuals within a population (demographic heterogeneity). Mechanistic stochastic models that include all of these factors have not previously been developed to examine their combined effects on extinction risk. Here we derive a family of stochastic Ricker models using different combinations of all these stochastic factors, and show that extinction risk depends strongly on the combination of factors that contribute to stochasticity. Furthermore, we show that only with the full stochastic model can the relative importance of environmental and demographic variability, and therefore extinction risk, be correctly determined. Using the full model, we find that demographic sources of stochasticity are the prominent cause of variability in a laboratory population of Tribolium castaneum (red flour beetle), whereas using only the standard simpler models would lead to the erroneous conclusion that environmental variability dominates. Our results demonstrate that current estimates of extinction risk for natural populations could be greatly underestimated because variability has been mistakenly attributed to the environment rather than the demographic factors described here that entail much higher extinction risk for the same variability level.  相似文献   

16.
Schizophrenia is a severe mental illness with a typically chronic course affecting nearly 1% of the human population. It is generally accepted that genetic factors have an important pathogenic role in a substantial portion of schizophrenia cases; however, despite decades of family studies, there is no agreed-upon mode of inheritance. The discovery of genetic aetiologic factors and resolution of the inheritance pattern(s) will undoubtably emerge from genetic linkage studies. With these objectives in mind, we undertook a linkage project, starting in 1985, in a previously well-documented kindred from north Sweden. Multipoint linkage analyses were used to screen the proximal long arm of chromosome 5 using restriction fragment length polymorphism (RFLP) markers at five loci and the distal long arm using RFLPs at two loci, one of which was the locus for the glucocorticoid receptor. We found strong evidence against linkage between schizophrenia and the seven loci. These results, together with the positive evidence for linkage of schizophrenia with markers in the proximal long arm of chromosome 5 lead us to conclude that the genetic factors underlying schizophrenia are heterogeneous.  相似文献   

17.
内蒙古高原生态环境质量评价指标体系及其应用研究   总被引:1,自引:0,他引:1  
内蒙古高原是蒙古高原的东南部分,生态环境比较恶劣.采用层次分析法,选取生态环境的自然条件、社会经济条件、环境生产力、土地利用、环境灾害和环境污染6个方面32个具体指标,以旗县为单元进行生态环境综合评价.根据评价结果将内蒙古高原各旗县的生态环境质量分为7级,并依据内蒙古高原各生态类型区存在的生态环境问题,有针对性地提出改善生态环境质量的措施与建议.  相似文献   

18.
结合2010年8月汶川地震灾区实地调查结果,将山区环境系统分为山区自然环境、山区社会环境和山区生态环境3个子环境系统,同时对强震造成的不同子环境系统的影响效应类型及特征进行了系统分析,包括自然环境的破坏效应、社会环境的震损效应和诱发效应,以及生态环境的生态效应.这些灾害效应均十分巨大,并且不是孤立存在的,处于一个共同体中相互影响,或同时发生,或前后相继,共同对灾区环境造成破坏.对此进行深入分析可以为强震改变后的山区环境的治理与恢复提供科学依据和理论基础.  相似文献   

19.
近年来,居住区建设越来越被人们重视,充分认识其内涵尤为重要。从居住区室内、室外环境的两方面,全面阐述了空间组织与变化、环境构成与塑造、自然因素、人工因素等对完整居住环境的影响。  相似文献   

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