论综合教学方法在提高细胞生物学教学质量上的作用     

帕孜来提·拜合提  吾甫尔·米吉提  计巧灵  阿布都卡地尔·阿布力孜  王咏星 《安徽农学通报》2014,(13):158-162

“细胞生物学”是近十几年高校和研究院所生物学专业硕士研究生必考课程,其课程的改革和教学水平的提高备受关注。该文对近年来细胞生物学的课程建设和民族班双语教学与2004-2010年学生考生物学专业研究生成绩的关系进行了分析,以此来评估细胞生物学课程建设和民族班双语教学对提高本科生生物学专业考研率方面的推动作用。  相似文献   

外来物种刺槐(Robinia pseudoacacia L.)在中国的研究进展     

尹达  ;杜宁  ;徐飞  ;王仁卿 《山东林业科技》2014,(6):92-99

刺槐作为一个外来种,近年来其研究受到越来越多的关注。本文介绍了刺槐在我国的基本生长特性(包括根系、种子、叶片、花)和在不同外界条件下(光照条件、盐胁迫、氮磷沉降、干旱胁迫、重金属胁迫、密度、AM真菌)的生理生态响应研究进展。探讨了刺槐病原菌引起的病害与防治、昆虫病害与防治、刺槐的有性、无性繁殖培育以及资源的开发利用,如薪炭材料、饲料、防风固沙、蜜源植物等,讨论了刺槐入侵理论与生态风险处理措施。评述了刺槐的区域性研究进展。最后提出了针对刺槐的未来研究展望。  相似文献   

Ecosystem‐based fisheries management: A perspective on the critique and development of the concept     

Susanna Lidstrm  Andrew F. Johnson 《Fish and Fisheries》2020,21(1):216-222

The concept of ecosystem‐based fisheries management (EBFM) has been subjected to debate since it was introduced in the late 1990s. The development of the concept seems to follow two separate but simultaneous trajectories of increased popularity but also sustained critique. This paper offers an analysis of potential mechanisms behind these disparate trajectories by drawing on a theoretical framework from science and technology studies (STS) centred around "black box" and actor‐network theory. To support our analysis, we perform an exploratory literature review of how the EBFM concept has been used in a selection of high impact fisheries research papers. We find that the popularity of EBFM does not guarantee its integrity, usefulness or analytical insight, but also that persistent critique of how the concept is used seems to be driving some change. We think that a continued trajectory of increased understanding, contextualization and discernibility of EBFM can help overcome the considerable ambiguity associated with the concept and make it increasingly useful to fisheries management. This means moving away from routine use of the term towards a practicable and tangible approach to improve fisheries sustainability.  相似文献   

构建和谐的公共图书馆服务文化   总被引：1，自引：0，他引：1  

李雪仙 《农业图书情报学刊》2010,22(4):254-257

论述了图书馆服务文化的内涵与特征、功能，探讨了构建和谐图书馆服务文化的意义和作用，和谐图书馆服务文化的管理手段，提出了构建和谐的图书馆服务文化的若干建议。  相似文献   

视网膜母细胞瘤109例分析   总被引：3，自引：0，他引：3  

龙心光  王映芬 《湛江医学院学报》1999,17(3):222-223

目的：分析视网膜母细胞瘤的发病特点和诊治规律。方法；收集本院近２３ａ来的１０９例ＲＢ病毒，对其临床特点，病理表现，治疗，预后及家系调查作一回顾性分析。结果：７７．１％的病例就诊年龄小于５岁。２２例为双眼发病，９例具有肿瘤家族史。１０９例中以晚期虱阳多见，病理检查大多可见有视神经和巩膜浸润。  相似文献   

The Importance of the Bolivian Wild Potato Species in Breeding for Globodera pallida Resistance     

M. T. Jackson    J. G. Hawkes    Beatrice S  Male-Kayiwa N. W. M. Wanyera 《Plant Breeding》1988,101(4):261-268

Screening for resistance to the potato cyst nematode, Globodera pallida, in potatoes from. Bolivia, was carried out in 1983 and 1984, using a mixture of four nematode populations representing pathotypes Pa₁, Pa₂ and Pa₃ From the 66 accessions of 17 species and subspecies evaluated, highly resistant genotypes were identified in 21 accessions from seven species. All had Pf/Pi values of 2 or less, whereas the susceptible control, Solanum tuberosum cv. ‘Disiree’ had Pf/Pi values of more than 2G in both tests. Two diploid wild species, S. brevicaule and S. leptophyes, showed the best resistant. The geographical distributional of resistant populations and the evolution of resistance in wild potato populations are discussed.  相似文献   

The nature of the Bolivian weed potato species Solanum sucrense Hawkes     

D. Astley  J. G. Hawkes 《Euphytica》1979,28(3):685-696

Summary Two theories for the origin of the Bolivian weed potato species Solanum sucrense Hawkes have been tested. The first was that it had an allopolyploid origin as a hybrid of the cultivated tetraploid S. tuberosum ssp. andigena (Juz. et Buk.) Hawkes with the wild/weed tetraploid cytotype of S. oplocense Hawkes. The second hypothesis postulated that it was a cross of the weed diploid species S. sparsipilum (Bitt.) Juz. et Buk. with S. oplocense.Synthetic hybrids of S. tuberosum ssp. andigena x S. oplocense and of S. sparsipilum x S. oplocense have been compared morphologically with S. sucrense accessions. Their crossability has also been investigated.The crossability and morphological studies strongly suggested that the former hypothesis was the more likely. This was borne out by observations made on the 1974 University of Birmingham Expedition when segregating populations of S. sucrense and S. oplocense were collected growing with feral S. tuberosum ssp. andigena.The evidence from this study indicates that the S. tuberosum ssp. andigena x S. oplocense hybrid has formed the basis of the S. sucrense gene pool. It is suggested that this hybridogenic taxon be maintained under the name Solanum x sucrense.The clarification of the taxonomic relationships of these three species will be of interest to Globodera resistance breeders, in view of the fact that these taxa are resistant to various pathotypes of the golden nematode.  相似文献   

Ecological lessons from long-term studies in experimental forests: Ponderosa pine silviculture at Pringle Falls Experimental Forest, central Oregon     

Andrew Youngblood 《Forest Ecology and Management》2011,261(5):937-947

The United States Department of Agriculture (USDA) Forest Service celebrated the 100th anniversary of its network of experimental forests in 2008. For a century, the network of experimental forests have contributed immensely—both in the US and around the world—to the practical understanding of the environment and to the formation of management approaches and policies that affect our use of forests and the natural resources they contain. Experimental forests provide places for long-term science and management studies in major vegetation types across the 789,140 km² of public land administered by the Forest Service. They also provide an incredible wealth of records and knowledge of environmental change in natural and managed forest ecosystems across the United States. Pringle Falls Experimental Forest (Pringle Falls), southwest of Bend, Oregon, is the oldest experimental forest in the Pacific Northwest and is the site of some of the earliest forest management and silviculture research in this region. Research at this site began in 1914, and it was formally established as part of the national network of experimental forests in 1931 as a center for silviculture, forest management, and insect and disease research in ponderosa pine forests east of the Oregon Cascade Range. As part of the celebration of the Centennial Anniversary of the network of experimental forests, it is timely to examine a few of the ecological lessons that have resulted from long-term studies at Pringle Falls. Two different yet interconnected themes are traced: (1) management of existing old-growth ponderosa pine; and (2) management of young or immature ponderosa pine. Examples of ecological lessons, drawn from long-term studies established or followed by James W. Barrett, Matt D. Busse, Patrick H. Cochran, Walter G. Dahms, F. Paul Keen, Ernest L. Kolbe, Edwin L. Mowat, William W. Oliver, Ram Oren, Chester T. Youngberg, and Jianwei Zhang illustrate how work at Pringle Falls has both pursued and influenced societal demands for forest management strategies, and how this trajectory has cycled back to the themes under which the experimental forest was first established. Finally, these two themes are integrated as drivers for new landscape-scale long-term research at Pringle Falls, designed to evaluate the effects of thinning and fuel reduction treatments on multiple, interacting forest stresses of fire, insects, wind, and climate change.  相似文献   

Monitoring of heavy metals in protected forest catchments in Sweden     

Mats Aastrup  Åke Iverfeldt  Lage Bringmark  Hans Kvarnäs  Bo Thunholm  Hans Hultberg 《Water, air, and soil pollution》1995,85(2):755-760

Long-term integrated catchment monitoring within the Swedish Environmental Monitoring Programme (PMK) aims primarely at the fate and effects of pollutants in mature ecosystems, mainly protected boreal forests. The measurements that were conducted since the early eighties, with some variation, included deposition, throughfall, litterfall and the chemistry of soil water, groundwater and runoff water.Together with, or perhaps partly due to acidification, accumulation and transport of heavy metals are a serious threat to the ecosystem and in the end to the health of human beings. This paper discuss the behaviour of Hg, Pb, Cd, Zn and Cu based on the experiece gained from the studies in the small catchment areas. The importance of present deposition, soil storage and biogeochemical condition for metal mobility to the transport of metals is discussed The storages of Hg and Pb have been built up during a long time span and are very large in comparison with the flux. The present atmospheric deposition have probably little impact on the flux, which rather is governed by the biogeochemical conditions. There is still a small accumulation of Cd, but its great mobility under acidic conditions makes input and output almost in balance. A reduction in deposition will probably have an immediate effect on flux, which also is the case for Zn. Cu generally accumulates in soil. The mobility and hence the flux are certainly regulated by the biogeochemical conditions, but more detailed studies are required to reveal the general mecanisms for Cu transport within the catchment.  相似文献   

The tyranny of taste: the case of organic rice in Cambodia     

Thavat M 《Asia Pacific viewpoint》2011,52(3):285-298

Fair-trade and organic products are often sold at price premiums justified by smaller production volumes that are associated with greater social and environmental responsibility. The consumption of these products confers on the consumer a greater sense of morality – and usually a claim to better taste. This paper tells the story of attempts to promote organic/fair-trade rice production by de facto organic Cambodian farmers for export to North American and European markets in order to assist poor farmers to trade their way out of poverty. It demonstrates that instead of promoting sustainable agriculture and fair trade between developed and developing markets, organic/fair-trade projects may impose First World consumer ideals and tastes that are out of step with the larger realities of agrarian transition in Cambodia and the wider region of developing Southeast Asia.  相似文献