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101.
This paper explores issues arising from the growing experience in the practice of just one of the traditions of multimethodology, namely that associated with a set of theoretical principles labeled pragmatic pluralism, and a methodological framework which is being developed to put these into action, namely, PANDA (participatory appraisal of needs and the development of action). The paper begins with a short historical introduction to the tradition of multimethodology under consideration; Section 2 then briefly describes some of the main features and principles involved in the PANDA framework. We then present three short case studies to illustrate different features of PANDA in action. The concluding section reflects on the issues that arise from the use of PANDA and discusses our future agenda for its development.  相似文献   
102.
基于Snake模型的低对比度噪声心脏MRI图像分割   总被引:4,自引:0,他引:4  
周则明  王平安  夏德深 《系统仿真学报》2004,16(11):2493-2496,2500
提出了一种基于Snake模型的低对比度、噪声心脏MRI图像分割算法。Snake模型通过轮廓线的变形得到感兴趣区域(ROI)的边界,但其分割结果依赖于初始轮廓线的位置,且变形曲线容易收敛于局部梯度极大值区域或从弱边界处泄漏,对于深度凹陷的区域也难以分割。通过增加局部面积能量项,扩大了Snake模型寻找边界的范围;在模糊C均值集群分类的基础上,构造模糊能量项,能够较好地处理心脏MRI图像中的弱边界、局部梯度极大值区域、伪影等现象。分割实验证明了改进的模型能够有效地分割低对比度、噪声心脏MRI图像。  相似文献   
103.
大熊猫电刺激采精及精液冷冻保存研究   总被引:5,自引:1,他引:5  
对卧龙自然保护区大熊猫研究中心的9只5.5-16.5岁的雄性大熊猫进行了17次电刺激采精,其中3只是能进行自然交配并繁殖了后代的种公兽,比较研究了精液离心、不同稀释液和冷冻方法对大熊猫精液超低温冷冻保存后的活力、运动状态、精子和顶体形态的影响。细冷冻是1种较好的超低温冷冻精液的方法。  相似文献   
104.
Dimethylsulphoniopropionate (DMSP) accounts for up to 10% of carbon fixed by marine phytoplankton in ocean surface waters, producing an estimated 11.7-103?Tmol S per year, most of which is processed by marine bacteria through the demethylation/demethiolation pathway. This pathway releases methanethiol (MeSH) instead of the climatically active gas dimethylsulphide (DMS) and enables marine microorganisms to assimilate the reduced sulphur. Despite recognition of this critical microbial transformation for over two decades, the biochemical pathway and enzymes responsible have remained unidentified. Here we show that three new enzymes related to fatty acid β-oxidation constitute the pathway that assimilates methylmercaptopropionate (MMPA), the first product of DMSP demethylation/demethiolation, and that two previously unknown coenzyme A (CoA) derivatives, 3-methylmercaptopropionyl-CoA (MMPA-CoA) and methylthioacryloyl-CoA (MTA-CoA), are formed as novel intermediates. A member of the marine roseobacters, Ruegeria pomeroyi DSS-3, requires the MMPA-CoA pathway for MMPA assimilation and MeSH production. This pathway and the ability to produce MeSH from MMPA are present in diverse bacteria, and the ubiquitous SAR11 clade bacterium Pelagibacter ubique possesses enzymes for at least the first two steps. Analysis of marine metagenomic data indicates that the pathway is widespread among bacterioplankton in the ocean surface waters, making it one of the most important known routes for acquisition of reduced carbon and sulphur by surface ocean heterotrophs.  相似文献   
105.
The Civil Partnership Act 2004, which came into force in December 2005 allowing same-sex couples in the UK to register their relationship for the first time, celebrated its fifth anniversary in December 2010. This article examines civil partnership in England and Wales, five years on from its introduction. The characteristics of those forming civil partnerships between 2005 and 2010 including age, sex and previous marital/civil partnership status are examined. These are then compared with the characteristics of those marrying over the same period. Further comparisons are also made between civil partnership dissolutions and divorce. The article presents estimates of the number of people currently in civil partnerships and children of civil partners. Finally the article examines attitudes towards same-sex and civil partner couples both in the UK and in other countries across Europe.  相似文献   
106.
107.
数十年前科学家就已经知道,人类基因至少有98%和黑猩猩完全相同……现在才开始探寻使人类从猿类中分离出来的究竟是哪些基因。人总喜欢认为自己是特殊的。因为人类具有交谈、书写和建筑复杂构造的能力,从而把自己从动物王国中分开来,并且形成精神上的差别。但是,将其归结到基因时,人类又和黑猩猩的两个物种极其相似,以至于生理学家贾里德·戴蒙德(JaredDiamond)称我们人类是“第三个黑猩猩物种”。经过了四分之一世纪的研究工作,可以肯定地确认人类和黑猩猩的任何基因组区,至少有98.5%的DNA是相同的。这就意味着只有很少一部…  相似文献   
108.
Zusammenfassung Nachweis der Entstehung einer Morphin-Toleranz und-Dependenz sowie von Veränderungen (Steigerung der Cholinesterase, Verminderung der Cholin-o-Acetyltransferase) von Enzymaktivitäten nach länger dauernden Morphingaben bei Neuroblastom-Kulturen.

Acknowledgements. This work was supported by grant No. U-2270 from the Health Research Council of the City of New York, a Lucy G. Moses Fellowship and an Irma T. Hirschl Career Scientist Award (to G.M.)  相似文献   
109.
Book Reviews     
Systemic Practice and Action Research -  相似文献   
110.
This article presents data on trends in the percentage of maternities taking place at home in the UK. As well as the national trend, the article examines how home maternity levels vary according to mother's age, number of previous live births within marriage, country of birth, region, local authority and NHS Trust. Examination of trends and variations in home maternity levels provides a context for debates regarding factors that may influence where women give birth.  相似文献   
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