共查询到20条相似文献，搜索用时 15 毫秒
1.
Jose Itzigsohn 《Ethnic and racial studies》2013,36(13):2299-2304
In this important book Roger Waldinger proposes a new analytical framework for the study of the migrant experience. He argues that migrants are at the same time immigrants and emigrants and their lives are subject to contradictory forces that on the one hand connect them with their country of origin and on the other hand pull them towards integrating into the country in which they reside. Waldinger affirms that this new analytical frame addresses the limits of assimilation theory – that is, methodological nationalism – and the blinders of the literature on transnationalism – that is, the exclusive focus on the connections between the places of origin and reception. I think that this is indeed true. At the same time, I believe that Waldinger's analysis has limits and blinders of its own. It is too critical of the literature on transnationalism and too uncritical concerning the process of incorporation. In spite of these limitations, this book is an original contribution to the study of the migration experience. 相似文献
2.
Tom Oosting Elena Hilario Maren Wellenreuther Peter A. Ritchie 《Ecology and evolution》2020,10(16):8643-8651
The more demanding requirements of DNA preservation for genomic research can be difficult to meet when field conditions limit the methodological approaches that can be used or cause samples to be stored in suboptimal conditions. Such limitations may increase rates of DNA degradation, potentially rendering samples unusable for applications such as genome‐wide sequencing. Nonetheless, little is known about the impact of suboptimal sampling conditions. We evaluated the performance of two widely used preservation solutions (1. DESS: 20% DMSO, 0.25 M EDTA, NaCl saturated solution, and 2. Ethanol >99.5%) under a range of storage conditions over a three‐month period (sampling at 1 day, 1 week, 2 weeks, 1 month, and 3 months) to provide practical guidelines for DNA preservation. DNA degradation was quantified as the reduction in average DNA fragment size over time (DNA fragmentation) because the size distribution of DNA segments plays a key role in generating genomic datasets. Tissues were collected from a marine teleost species, the Australasian snapper, Chrysophrys auratus. We found that the storage solution has a strong effect on DNA preservation. In DESS, DNA was only moderately degraded after three months of storage while DNA stored in ethanol showed high levels of DNA degradation already within 24 hr, making samples unsuitable for next‐generation sequencing. Here, we conclude that DESS was the most promising solution when storing samples for genomic applications. We recognize that the best preservation protocol is highly dependent on the organism, tissue type, and study design. We highly recommend performing similar experiments before beginning a study. This study highlights the importance of testing sample preservation protocols and provides both practical and economical advice to improve DNA preservation when sampling for genome‐wide applications. 相似文献
3.
Dominic Pasura 《Ethnic and racial studies》2013,36(1):199-218
In the last decade, the phenomenal growth of Zimbabwean congregations in Britain, responding to conditions in both the hostland and homeland, has received little scholarly attention. This article, drawing from an in-depth study of Zimbabwean Christians and the modes-of-incorporation framework, examines the ways in which the context of reception in the hostland shape, alter and influence the development of religious transnationalism among migrants. As this article will argue, Zimbabweans' mode of incorporation into Britain was mediated by a hostile reception from authorities, considerable prejudice and hostility from the host society and a weak pre-existing co-ethnic community. These conditions in the hostland reinforce migrants' transnational religious ties to the homeland. In addition, the article illustrates the contradictory ways in which respondents reproduce, contest and construct their transnational gendered identities. 相似文献
4.
目的 探索江苏常熟地区汉族人群在47个常染色体微单倍型基因座的遗传多态性,评估应用效能及法庭科学参数。方法 采用MHSeqTyper47混合DNA鉴定试剂盒进行基因座复合扩增及文库构建,使用MiSeq FGx测序平台进行测序,测得的数据应用MHTyper数据分析软件进行分析,对获得的样本遗传信息进行评估,结合千人基因组数据（1000 Genomes Project phase 3,1KG）评估群体间遗传分化指数及遗传距离,并计算法庭科学参数。结果 江苏常熟地区汉族人群与1KG中的中国北京群体的遗传分化和遗传距离最小,并得到最接近的有效等位基因数（Ae）,累积随机匹配概率（combined matching probability,CMP）与1KG中东亚参考人群的5个群体均接近,为1.25×10-36,累积非父排除概率达0.999 999 999 964 1。结论 本研究报告了47个微单倍型基因座在江苏常熟地区汉族人群中的等位基因频率及遗传多态性信息,为47个微单倍型在法医学应用中提供了数据基础。另外,比较了1KG参考人群与江苏常熟地区汉族人群的多态性差异,并揭示了47个微单倍型在江苏常熟地区汉族人群中的遗传结构。总的来说,1KG中的东亚人群参考数据更符合江苏常熟地区汉族人群的遗传特征。 相似文献
5.
Clio Der Sarkissian Morten E. Allentoft María C. ávila-Arcos Ross Barnett Paula F. Campos Enrico Cappellini Luca Ermini Ruth Fernández Rute da Fonseca Aurélien Ginolhac Anders J. Hansen Hákon Jónsson Thorfinn Korneliussen Ashot Margaryan Michael D. Martin J. Víctor Moreno-Mayar Maanasa Raghavan Morten Rasmussen Marcela Sandoval Velasco Hannes Schroeder Mikkel Schubert Andaine Seguin-Orlando Nathan Wales M. Thomas P. Gilbert Eske Willerslev Ludovic Orlando 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2015,370(1660)
The past decade has witnessed a revolution in ancient DNA (aDNA) research. Although the field''s focus was previously limited to mitochondrial DNA and a few nuclear markers, whole genome sequences from the deep past can now be retrieved. This breakthrough is tightly connected to the massive sequence throughput of next generation sequencing platforms and the ability to target short and degraded DNA molecules. Many ancient specimens previously unsuitable for DNA analyses because of extensive degradation can now successfully be used as source materials. Additionally, the analytical power obtained by increasing the number of sequence reads to billions effectively means that contamination issues that have haunted aDNA research for decades, particularly in human studies, can now be efficiently and confidently quantified. At present, whole genomes have been sequenced from ancient anatomically modern humans, archaic hominins, ancient pathogens and megafaunal species. Those have revealed important functional and phenotypic information, as well as unexpected adaptation, migration and admixture patterns. As such, the field of aDNA has entered the new era of genomics and has provided valuable information when testing specific hypotheses related to the past. 相似文献
6.
Richard Alba 《Ethnic and racial studies》2014,37(3):446-466
AbstractRacialization and assimilation offer alternative perspectives on the position of immigrant-origin populations in American society. We question the adequacy of either perspective alone in the early twenty-first century, taking Mexican Americans as our case in point. Re-analysing the child sample of the Mexican American Study Project, we uncover substantial heterogeneity marked by vulnerability to racialization at one end but proximity to the mainstream at the other. This heterogeneity reflects important variations in how education, intermarriage, mixed ancestry and geographic mobility have intersected for Mexican immigrants and their descendants over the twentieth century, and in turn shaped their ethnic identity. Finally, based on US census findings, we give reason to think that internal heterogeneity is increasing in the twenty-first century. Together, these findings suggest that future studies of immigrant adaptation in America must do a better job of accounting for heterogeneity, not just between but also within immigrant-origin populations. 相似文献
7.
高通量测序技术的快速发展对食品微生物发酵过程和机制研究产生了深刻的影响,主要体现在食品微生物生理功能、代谢能力和进化的研究以及食品微生物群落结构、动态变化及其对环境的响应机制等方面。另外,通过对食品微生物基因组和元基因组进行数据分析,也对食品发酵过程优化、微生物功能改造、食源性微生物疾病预防和控制等提供了重要的依据。本文总结了近年来利用高通量测序技术对食品微生物基因组和元基因组进行测序的研究,并探讨了测序技术的发展对食品微生物研究的影响及发展趋势。 相似文献
8.
Paul DiMaggio 《Ethnic and racial studies》2015,38(8):1236-1244
This paper proposes a systematic approach to the study of immigration and art by considering relevant theoretical concepts. We focus on the role of institutions and economic change as forces shaping the expressive alternatives of immigrants and their children. 相似文献
9.
Chao-Nan Fu Zhi-Qiong Mo Jun-Bo Yang Jie Cai Lin-Jiang Ye Jia-Yun Zou Han-Tao Qin Wei Zheng Peter M. Hollingsworth De-Zhu Li Lian-Ming Gao 《Molecular ecology resources》2022,22(1):404-414
Standard plant DNA barcodes based on 2–3 plastid regions, and nrDNA ITS show variable levels of resolution, and fail to discriminate among species in many plant groups. Genome skimming to recover complete plastid genome sequences and nrDNA arrays has been proposed as a solution to address these resolution limitations. However, few studies have empirically tested what gains are achieved in practice. Of particular interest is whether adding substantially more plastid and nrDNA characters will lead to an increase in discriminatory power, or whether the resolution limitations of standard plant barcodes are fundamentally due to plastid genomes and nrDNA not tracking species boundaries. To address this, we used genome skimming to recover near-complete plastid genomes and nuclear ribosomal DNA from Rhododendron species and compared discrimination success with standard plant barcodes. We sampled 218 individuals representing 145 species of this species-rich and taxonomically difficult genus, focusing on the global biodiversity hotspots of the Himalaya-Hengduan Mountains. Only 33% of species were distinguished using ITS+matK+rbcL+trnH-psbA. In contrast, 55% of species were distinguished using plastid genome and nrDNA sequences. The vast majority of this increase is due to the additional plastid characters. Thus, despite previous studies showing an asymptote in discrimination success beyond 3–4 plastid regions, these results show that a demonstrable increase in discriminatory power is possible with extensive plastid genome data. However, despite these gains, many species remain unresolved, and these results also reinforce the need to access multiple unlinked nuclear loci to obtain transformative gains in species discrimination in plants. 相似文献
10.
《Ethnic and racial studies》2012,35(1):3-22
Abstract On the basis of a study of forty health care delivery institutions in Florida, California, and New Jersey, this paper examines the interaction between the immigration and health systems in the USA. We investigate barriers to care encountered by the foreign born, especially unauthorized immigrants, and the systemic contradictions between demand for their labour and the absence of an effective immigration policy. Lack of access and high costs have forced the uninsured poor into a series of coping strategies, which we describe in relation to commercial medicine. We highlight regional differences and the importance of local politics and history in shaping health care alternatives for the foreign born. 相似文献
11.
Xiaoling Yu Wenqian Jiang Yang Shi Hanhui Ye Jun Lin 《Journal of cellular and molecular medicine》2019,23(11):7143-7150
Infectious diseases are a type of disease caused by pathogenic microorganisms. Although the discovery of antibiotics changed the treatment of infectious diseases and reduced the mortality of bacterial infections, resistant bacterial strains have emerged. Anti‐infective therapy based on aetiological evidence is the gold standard for clinical treatment, but the time lag and low positive culture rate of traditional methods of pathogen diagnosis leads to relative difficulty in obtaining the evidence of pathogens. Compared with traditional methods of pathogenic diagnosis, next‐generation and third‐generation sequencing technologies have many advantages in the detection of pathogenic microorganisms. In this review, we mainly introduce recent progress in research on pathogenic diagnostic technology and the applications of sequencing technology in the diagnosis of pathogenic microorganisms. This review provides new insights into the application of sequencing technology in the clinical diagnosis of microorganisms. 相似文献
12.
插入位点分析对于金针菇功能基因组学的研究极为重要,分析方法常用反向PCR、热不对称交错PCR、Tail-PCR、染色体步移等,存在操作复杂、消耗时间长、特异性较差、效率低等缺点。近年来开始应用基因组重测序的方法,对转化子逐一测序与分析,工作量较大、费用较高。本研究应用矩阵设计,把多个转化子的DNA混合构成样品池,重测序后分析插入位点,M个样品池的测序数据可分析M×(M+1)/2个转化子的插入位点。应用矩阵设计构建6个样品池检测21个转化子,获得21个插入位点,表明这种方法可行、适合大样本分析,如突变体库。 相似文献
13.
Although the diploid nature has been observed for over 50 years, phasing the diploid is still a laborious task. The speed and throughput of next generation sequencing have largely increased in the past decades. However, the short read-length remains one of the biggest challenges of haplotype analysis. For instance, reads as short as 150 bp span no more than one variant in most cases. Numerous experimental technologies have been developed to overcome this challenge. Distance, complexity and accuracy of the linkages obtained are the main factors to evaluate the efficiency of whole genome haplotyping methods. Here, we review these experimental technologies, evaluating their efficiency in linkages obtaining and system complexity. The technologies are organized into four categories based on its strategy: (i) chromosomes separation, (ii) dilution pools, (iii) crosslinking and proximity ligation, (ix) long-read technologies. Within each category, several subsections are listed to classify each technology. Innovative experimental strategies are expected to have high-quality performance, low cost and be labor-saving, which will be largely desired in the future. 相似文献
14.
15.
16.
Shin-ichiro Takebayashi Shin Ogata Masato Ogata Katsuzumi Okumura 《Bioscience, biotechnology, and biochemistry》2013,77(12):2098-2100
ABSTRACTHere, we show that semiconductor-based sequencing technology can be used to map mammalian replication domains, chromosomal units with similar DNA replication timing. Replicating DNA purified from mammalian cells was successfully sequenced by the Ion Torrent platform. The resultant replication domain map of mouse embryonic stem cells is comparable to those obtained by the conventional microarray-based method. 相似文献
17.
18.
DNA microarray and next-generation DNA sequencing technologies are important tools for high-throughput genome research, in revealing both the structural and functional characteristics of genomes. In the past decade the DNA microarray technologies have been widely applied in the studies of functional genomics, systems biology and pharmacogenomics. The next-generation DNA sequencing method was first introduced by the 454 Company in 2003, immediately followed by the establishment of the Solexa and Solid techniques by other biotech companies. Though it has not been long since the first emergence of this technology, with the fast and impressive improvement, the application of this technology has extended to almost all fields of genomics research, as a rival challenging the existing DNA microarray technology. This paper briefly reviews the working principles of these two technologies as well as their application and perspectives in genome research. Supported by the National High-Tech Research Program of China (Grant No.2006AA020704) and Shanghai Science and Technology Commission (Grant No. 05DZ22201) 相似文献
19.