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891.
This article revisits recent debates about the responsibilities of public scholarship. The piece argues that writing in a range of fields has engaged with issues of racism, in particular as racism has been manifested in the ‘war on terror’, but that this discussion has been muted within the sub-field of race and ethnic studies. There is a discussion of the impact of pressures to demonstrate the ‘usefulness’ of research to a wider public and the limits that this can place on the formulation of research. This argument is expanded through consideration of the author's experience of researching and lobbying with community and campaigning groups. The piece goes on to consider the implications of the marketization of higher education for critical scholarship and concludes that there is value in a more ‘private’ sociology that may not be easily accommodated in the marketized university.  相似文献   
892.
This article asks what might be the possibilities and the limits of what academic research might strive for when we engage with the politics of race. It argues for a reflexive engagement with the historically sensitive production of critical ethnographic knowledge. Ethnography and the anthropological tradition, challenged in much politically progressive literature on race and ethnicity as a form of exoticism, a medium of orientialism and a field of misrepresentation, need to be considered in interdisciplinary traditions of knowledge production in the humanities and social sciences that examine efficacy and causality as central concepts of analysis.  相似文献   
893.
This article suggests the usefulness of an ecological approach in studying the development of teachers' ethnic stereotypes in schools. It builds on existing research in this area by exploring the importance of nationally specific educational contexts and school characteristics on the development of teachers' stereotypes of Turkish minority students. Observation and interview data from case-study research involving one Flemish (Belgian) and one English secondary, multicultural inner-city school suggest differences between Flemish and English teachers' ethnic stereotypes. These differences can in part be explained by the influence of nationally specific regulations governing teachers' power to evaluate students, a nationally specific policy on ethnic minority cultures and needs, the ethnic and gender composition of the school's student and staff population, and the enforcement of an inclusive school policy by the school's senior management. The conclusions discuss implications for further research on ethnic stereotyping and discrimination in schools.  相似文献   
894.
The renewed upsurge in ethnic and communal conflicts in Nigeria has generated increased interests in ethnic conflicts studies. A dominant approach in the literature is the concentration on the study of inter-ethnic conflicts at the expense of intra-ethnic conflicts. However, experiences have shown that intra-ethnic conflicts are as equally preponderant and bloody as inter-ethnic conflicts, suggesting that considerable research attention be directed at them. This paper sheds light on the perseverance of sub-ethnic identities and conflicts in Nigeria. It traces the evolution of ethnic conflict research in Nigeria, explores the existing literature on ethnic conflicts and points to the neglect of intra-ethnic conflicts. The consequence, the paper concludes, is that knowledge of ethnic conflicts in Nigeria is likely to be insufficient and undeveloped.  相似文献   
895.

Background and Aims

Plant genotypic mixtures have the potential to increase yield stability in variable, often unpredictable environments, yet knowledge of the specific mechanisms underlying enhanced yield stability remains limited. Field studies are constrained by environmental conditions which cannot be fully controlled and thus reproduced. A suitable model system would allow reproducible experiments on processes operating within crop genetic mixtures.

Methods

Phenotypically dissimilar genotypes of Arabidopsis thaliana were grown in monocultures and mixtures under high levels of competition for abiotic resources. Seed production, flowering time and rosette size were recorded.

Key Results

Mixtures achieved high yield stability across environments through compensatory interactions. Compensation was greatest when plants were under high levels of heat and nutrient stress. Competitive ability and mixture performance were predictable from above-ground phenotypic traits even though below-ground competition appeared to be more intense.

Conclusions

This study indicates that the mixing ability of plant genotypes can be predicted from their phenotypes expressed in a range of relevant environments, and implies that a phenotypic screen of genotypes could improve the selection of suitable components of genotypic mixtures in agriculture intended to be resilient to environmental stress.  相似文献   
896.
Plant microRNAs (miRNAs) are crucial for the regulation of gene expression, which is involved in almost all the important biological processes. In the cytoplasm, the miRNA strand is selectively incorporated into a specific Argonaute (AGO)-associated gene silencing complex, while the miRNA* is degraded rapidly. Thus, most miRNA*s were thought to be biologically meaningless. Interestingly, several recent reports in both plants and animals have shaken this notion. Many miRNA*s were demonstrated to possess regulatory roles in gene expression. However, the low accumulation levels of most miRNA*s raise the question whether the activities of this small RNA (sRNA) species are widespread in plants. Here, by using publicly available sRNA high-throughput sequencing data, we found that the accumulation levels of several miRNA*s could be much higher than those of their miRNA partners in certain organs, mutants and/or AGO-associated silencing complexes of both Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa). Based on target prediction and degradome sequencing data-based validation, some of these highly accumulated miRNA*s were indicated to possess cleavage-based potential regulatory role on certain targets. Besides, some interesting biological interpretations were obtained based on the accumulation patterns of the miRNA*s, the annotations of the target genes, and literature mining. Taken together, the expanded list of the highly accumulated miRNA*s along with their potential target genes discovered in this study further strengthened the current notion that certain members of the miRNA* species are biologically relevant, which needs further inspection.  相似文献   
897.
ABSTRACT

Policy and campaigning messages related to dog ownership and welfare center on the concept of responsible ownership. However, the perspectives and experiences of pet owners and how they perceive and perform their responsibilities has not been studied in depth. This qualitative study used conversations about owning and walking dogs in order to elucidate beliefs and views about responsibility in dog ownership. Data comprised 12 in-depth interviews with dog-owning households, 14 short interviews with dog owners while walking their dogs or representing their breed at a dog show, and autoethnography of the first author’s experiences owning and walking dogs. All participants considered themselves responsible dog owners, yet there was great variation in key aspects of their dog-owning behavior. The feelings of responsibility were rooted in the valued unconditional and reciprocal love that owners believed underpinned their human–dog bond. Dogs were described as dependents, similar to, but different from, children. In deciding how to look after their dogs, owners sought to balance their views of dogs as kin, having individual needs to be met, with consideration of the needs of others. Four processes through which issues of irresponsible dog ownership may arise were suggested: owner–dog relationship being too weak or too strong; differences in interpretation of what is best for the dog; difficulties predicting and avoiding situations of conflict; and differences in tolerance of negative impacts of dog ownership. While “responsible dog ownership” has considerable appeal as a concept, how it is perceived and interpreted varies so extensively that simply telling owners that they should “be responsible” is of limited use as a message to promote behavior change. Facilitating “responsible dog ownership” and reducing “irresponsible dog owner” behaviors relies on a detailed understanding of the variables which influence how the dog’s role is constructed within the family and the wider society.  相似文献   
898.
899.
自世界工业革命以来,化石燃料的大量使用以及人类对自然环境的过度破坏,致使大气CO2浓度不断升高.研究大气CO2浓度升高介导的农业生态系统内植物、植食性昆虫及其天敌的适应机制,对于阐明气候变化下农业害虫爆发危害规律,指导防控与减排具有重要意义.本文综述了大气CO2浓度升高对农业生态系统中植物、植食性昆虫及天敌的影响,主要包括:1)相关研究方法的改进;2)大气CO2浓度升高介导的寄主植物营养和次生代谢物质的变化;3)大气CO2浓度升高对以植物为食的昆虫的个体生长发育、种群数量、行为的影响;4)天敌昆虫的生物学及捕食量与寄生率变化.最后对今后的研究方向进行了展望.  相似文献   
900.
丹参酮是一类从传统中药材丹参中提取的醌类化合物,近年研究发现其具有多种生物活性,包括抗氧化,抗炎,抑制增殖,诱导凋亡等作用,本文针对丹参酮自2008年至今的国内外抗肿瘤研究进行综述。  相似文献   
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