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1.
通过对有丝分裂中期及减数分裂终变期染色体数目统计,形态、行为的观察,发现莱麦草染色体呈现广泛的变异:有丝分裂中期株内染色体数目在2n=11──56内变化,含有本物种染色体数目2n=28的细胞仅占统计数的27.8%。减数分裂终变期出现36%具非整倍性的花粉母细胞,染色体数除数目变异外还有结构变异如Robertson易位等。本文对该种进行了染色体组分析,确认其为同源四倍体。同时对该物种株内产生混倍性的原因,在物种进化上的意义进行了探讨。  相似文献   

2.
本文根据西辽河流域鲇鱼的染色体核型特征,结合形态学数据,鉴定该种鱼为鲇鱼( Siluruas asotus) 。并对其适应性和育种价值的细胞学基础进行了讨论  相似文献   

3.
蚕豆根尖微核率(MCW)、染色体畸变率(CAF)与重金属离子间有明显的效应-剂量关系。在较低剂量情况下,两者呈直线回归;在较高条件下,据本实验(采用Ph和Hg)结果,随处理浓度的提高,其关系曲线为“M”形。通过对聚丙烯酸胺过氧化物同功酶电泳的结果及前人成果分析,认为这与同工酶变化及抗性酶活性有关。另外,对于Pb、Hg处理,间期MCNF,中期CAF和后期CAF随浓度的升高并不同步达到最大值,即中期CAF与剂量的线性区段长于其他两者。  相似文献   

4.
在减数分裂研究的基础上对赖草染色体组型、非整倍体进行了调查研究。结果表明:赖草(Aneurolepidiumdasystachys)的染色体组型公式为2n=4x=28=28m(4SAT)。但核仁染色体数目有一定的变异,调查了80株,其中70%含有二对核仁染色体,30%含有一对核仁染色体。赖草群体中非整倍体频率较高,调查了191株,其中2n=28(整倍体)占6963%,超倍体占2.61%,亚倍体占27.76%。通过观察分析认为,产生非整倍体的主要细胞学原因是减数分裂前期Ⅰ不联会或联会消失以及减数分裂不分离。亦对赖草的非整倍体分离和利用进行了探讨。  相似文献   

5.
西方文化与人格研究的历程   总被引:8,自引:0,他引:8  
西方文化与人格研究的历程李富强文化与人格(Culture-and-personality)研究又称心理人类学(PsychologicalAnthropology),是文化人类学中一门较新的边缘性分支学科①。本文拟对其产生和发展的历史作一简单介绍。文化...  相似文献   

6.
龙与中华文化的多元起源钟年无论是在生物的起源、人类的起源还是文化的起源问题上,历来者l;有一元发生论(Monogenism)与多元发生论(Polosenism)的争锋.本文涉及的只是文化的起源问题。在人类文化研究史上·也出现过单一起源的论调.其中最著...  相似文献   

7.
美国学者杜磊(Dru.C Gladney)在丰富的田野工作的基础上,先后出版了两部关于中国回族穆斯林的著作,在国内外回族研究界有广泛影响。他主要描述了四个不同类型的回族社区,即:宁夏纳家户村(西北)、北京郊区常营回族乡(东部农村)、北京牛街(都市)、福建陈埭回族镇(东南)。以揭示回族民族认同和“清真”观念的宽泛表达,及回族民族认同与政府政策的互动关系。本文是其所著《中国的民族认同》(Ethnic Identity inChina: The Making of a Muslim Minority Nationality,Harcourt Brace College Publishers, 1998)一书的第六章。得到原作者的许可,在此发表,以飨读者。因篇幅所限,有删节。  相似文献   

8.
论“民族-国家”与“多民族国家”   总被引:13,自引:1,他引:12  
用“民族”一词通译或混译欧洲语言(以英语为例)中的nation、nationality、people、ethnicgroup不只是学术术语混乱的问题,而且隐含着政治问题。不宜用ethnicgroup来指称我国的“民族”。“国民-国家”(nation-state)理论在历史上起过进步作用,但它不是普遍真理,在当代已成为引发民族冲突、民族分裂的祸源,危害着多民族国家的巩固和统一。本世纪初在美洲产生并对许多国家有影响的“多族群国民-国家”(nation-stateofmultipleethnicgroups)的构想,是对传统的“国民-国家”理论的修正,但它不符合小民族的现时愿望与发展趋势。基于这种构想制定的民族政策在实践中普遍归于失败。“多民族国家”(stateofmultiplenationalities)的理论具有强大的生命力和重要的现实意义。  相似文献   

9.
鱼类人工诱导三倍体和雌核发育二倍体研究进展   总被引:1,自引:0,他引:1  
在育种学上,三倍体(Triploid)与雌核发育(Gyapenesis)的人工诱导都属于“染色体组工程”(Genomeengineeriflg)的范畴。由于它们有控制染色体组和性别的潜力,因此,这些技术正在引起人们的浓厚兴趣。雌核发育和多倍体现象在植物界是相当普遍的,动物界却很少。鱼类系体外受精,产卵量大,所以是研究这一现象的理想材料。1鱼类的天然多倍体和雌核发育现象1.1天然雌核发育的鱼类在鱼类中,最早发现美洲的胎属(poeciliaformosa)(Hubbs,1946)鱼类是行雌核发育的单性鱼类。随后又发现银鲫(Chrassiusauratusgihelio)(蒋一,1982…  相似文献   

10.
书讯     
书讯大型画册——《中国的民族》(中、英文两种版本)出版。该书作者为杜若甫(中科院遗传所研究员)、叶傅异(美国西北大学教授)。本书是作者以人类学、遗传学为基础,研究我国56个民族体质人类学和文化人类学的科研成果。本书以图文并茂形式介绍了每个民族的族名、...  相似文献   

11.
ABSTRACT

While in Western literature, migration is generally considered an individual or (nuclear) household phenomenon, Indian context adds the strong presence of parents and extended family to the constellation. This paper addresses how significant others shape the life course events and the migration trajectories of highly skilled Indian migrants to the Netherlands and UK. We employ a qualitative approach to the life course framework to highlight the linked lives that can alter the migration decisions. Our findings are drawn from 47 semi-structured biographic interviews. The results underscore how further migration decisions are often informed by the implications of the different life stages of the linked lives, the key elements being care-giving by and for the parents. Furthermore, we also illustrate how migration provides space for negotiating social norms and expectations: due to the geographical distance between migrants and their parents, the local (non-Indian) context plays a bigger role and thus the need for and timing of conformity with norms can be postponed. The understanding of family life in transnational settings will be enriched when individuals are embedded within the cultural background and linked lives are extended beyond the immediate nuclear family.  相似文献   

12.
Ageing of migrants in Europe has become an important policy issue, especially within the context of health inequalities and increasing health care costs. Based on in-depth interviews with older Alevi/Kurdish refugees in London, we explore the cumulative impact of difficult migration trajectories on the experience of ageing. The findings highlight the important role of cultural capital and transnational ties throughout the refugees’ migration journeys and particularly at old age. However, the study indicates the double edge impact of strong ‘solidarity’ bonds, increasing isolation at old age due to lack of accumulation of capital and knowledge, particularly language, which are important in accessing health and social care services at old age.  相似文献   

13.
The tendency for internal migration is limited among Palestinian–Israelis, due to internal and external barriers. However, in recent years many educated Palestinian–Israeli single women have migrated in search of work. This article is based on qualitative research I conducted among Palestinian–Israeli single women who moved south in Israel. This migration originates in economic and occupational hardship but may lead to mobility and autonomy for these women and shapes gender relations in their communities. Using the terminology coined by Walby (1989)—“dual systems theories”—and by Kandiyoti (1988)—“bargaining with patriarchy”, I will examine how these women bargain with capitalism, deconstruct patriarchal regimes, and challenge accepted gender relations.  相似文献   

14.
Although scholars consistently show that class-specific parenting, influenced by the resources parents have due to their socio-economic position, is one of the most important factors for children’s different life chances and outcomes as adults, migrants’ parenting is usually analysed with a focus on their ethnicity or country of origin. Building on cultural perspectives on class, this study demonstrates that migrant parents are differently endowed with institutionalised and embodied cultural capital, which shapes their parenting and therewith their children’s educational opportunities. Specifically, parents differ in their trust in school authorities, the way they define their own role in shaping their children’s education, and their self-esteem and confidence in assessing their children’s abilities and performance. This study is based on the accounts of parents who migrated from Poland to Germany and shows that due to their class position, middle-class parents possess robust forms of cultural capital that they can transfer to their children in the context of migration. This finding makes a case for the relevance of class in the context of migration and thereby adds an important perspective to the study of migrants’ inequalities in education, which tends to focus on ‘ethnic’ differences between migrants and ‘natives’.  相似文献   

15.
ABSTRACT

In the past few years, spaces of transit have become prominent sites for people seeking refuge in Europe. From railway stations and parks in European cities, to informal settlements around Calais, to the hotspots in Italy and Greece, the movements of people and the techniques that govern them are at the heart of what has been misnamed the ‘European refugee crisis’. Drawing on qualitative fieldwork, this article takes spaces of transit as a vantage point for interrogating the relationship between mobility, migration management and violence, focusing on the fracturing of journeys due to forced and obstructed mobility both outside and within the EU. We develop the notion of ‘politics of exhaustion’ to highlight the impact and protracted character of these forms of migration management – its accumulated effects over time and across spaces – yet without reducing people seeking refuge to passive victims. Struggles for mobility are closely related to the existence and continued adaptation of migration management practices. The notion of fracturing can thus be employed not only to make sense of the violent effects of migration management but also the ways in which conventional conceptions of state and citizenship are challenged by the emergence of alternative living spaces, communities and politics.  相似文献   

16.
“Unveiled or Unemployed”—that is the verdict for many women with Muslim migration background in the German employment sector. Since the infamous “headscarf case” of Fereshta Ludin, who was denied a teaching position at a public school in the state of Baden-Württemberg due to her wearing the headscarf in 1998, institutional actions by the legislature and the judiciary on religiously affiliated clothing, such as the headscarf, have framed debates on immigration, integration, and employment in the country. This article examines the German employment sector as a space for integration and makes suggestions for an optimization of employment integration for women with Muslim migration background. I propose that optimized employment integration necessitates a holistic approach that begins with a coherent legal–institutional framework and a corresponding unified enforcement thereof. I argue that the current legal–institutional framework and its enforcement present significant structural challenges in the employment integration of women with Muslim migration background, especially as it concerns the headscarf. Integration to the employment sector can only begin with and be sustained upon an “integration friendly” legal–institutional framework that does not allow for unequal treatment under exceptional circumstances and that is not enforced on an ad hoc basis. My claim is premised on the understanding of integration as a structural matter that requires a legal–institutional framework upon which state accommodation, considerate of a diverse society and demographic changes, can take place.  相似文献   

17.
Contemporary EU governance of migration outside its territorial borders aims to control mobility through policing measures, but also to shape the subjectivities of potential migrants so that they ‘discipline themselves’ to fit European immigration priorities. This is illustrated by the organisation by intergovernmental and non-governmental agencies, in several African countries, of ‘information’ campaigns and participatory activities to convince youths to stay rather than emigrate. Through an ethnographic account of my encounter with the leaders of a youth group involved in participatory activities in Dakar (Senegal), this article explores the assumption that youths can be governed in this way. I argue that awareness-raising initiatives had little hold over the thoughts of local youths, and were reappropriated by the association leaders I met. This was largely due to ‘discontinuities’ between agencies’ and local youths’ perceptions of migration and development, as well as NGOs’ past and present work with youth group leaders. Theoretically, these conclusions add to research emphasising the force of human mobility over EU policing measures, whilst also highlighting the agentive role of local dynamics.  相似文献   

18.
杜伟 《世界民族》2011,(1):70-74
明治政府开启了日本现代大规模海外移民潮的序幕。这一时期日本海外移民潮的形成是由特定的国际、国内环境决定的,国际上人口大规模的转移以及日本明治维新所带来的一系列政治、经济及社会的变革是形成这一移民潮的背景。明治政府主导下的移民行为有一些值得关注的特点,如移民的目的地主要是美洲,移民的主体为契约劳工,移民大多来自日本西南部,移民在目的地国所从事的职业多与农业相关等。  相似文献   

19.
ABSTRACT

Increased migration across the Mediterranean to Europe during 2015 was associated with growing interest in generating new research evidence to assist policymakers in understanding the complexities of migration and improve policy responses. In the UK, this was reflected in funding by the Economic and Social Research Council for a Mediterranean Migration Research Programme. Drawing on evidence from the programme, this volume explores the nature of Europe’s ‘migration crisis’ and the extent to which the development of new migration management policies was grounded in evidence about the causes, drivers and consequences of migration to Europe. The authors conclude that there is a substantial ‘gap’ between the now significant body of evidence examining migration processes and European Union policy responses. This gap is attributed to three main factors: the long-standing ‘paradigm war’ in social research between positivist, interpretivist and critical approaches which means that what counts as ‘evidence’ is contested; competing knowledge claims associated with research and other forms of evidence used to construct and/or support policy narratives; and, perhaps most importantly, the politics of policymaking, which has resulted in policies based on underlying assumptions and vested interests rather than research evidence, even where this evidence is funded directly by European governments.  相似文献   

20.
The relationship between migration and gender roles has received increased attention in recent decades but most of the literature has focused on transnational migration while the relationships between transnational and internal migration, and gender roles and internal migration have not been widely studied. In this paper, I analyse internal migration as a ‘transborder experience’. I argue that indigenous women from Zegache who engage in internal migration to Mexico City pose greater challenges to ‘traditional’ gender roles in their community because their experience as single young women navigating Mexico’s capital and their reliance on female social networks allow them to obtain social legitimation by claiming migration experience and courageousness. I contrast migration to Mexico City with transnational migration. Although transnational migration challenges, to some extent, existing gender roles, women from Zegache who migrate transnationally often do so as part of couples and within gendered social networks.  相似文献   

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