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71.
It has become increasingly difficult to keep pace with the amount of information being generated about how to evaluate organizations. If it were not enough that the situation is made difficult by the sheer mass of material on evaluation, clarity is further hindered by many of the publications on the subject failing to make explicit the principles and assumptions upon which they are based. This was the situation confronting the authors when they began a national project with the National Association of Councils for Voluntary Service on the evaluation of the performance of Councils for Voluntary Service. In an attempt to bring some order to the field, this paper adopts a systems and contingency approach to elucidate the nature and practical usefulness of the different methods of evaluation. It first seeks, using some tools of Checkland's soft systems methodology, to present a systematic analysis of the subject of evaluation. Then, in the light of the analysis, an attempt is made to formulate a simple classification of approaches to evaluation which serves to match the different forms of evaluation to the contexts in which they are most appropriate for use. 相似文献
72.
Robert L. Flood Michael C. Jackson David Schecter 《Systemic Practice and Action Research》1992,5(1):79-83
The development of TSI represents a real advance in management science in our view. Further developments are necessary however. This Research Note has outlined what we currently consider to be key issues in this development. We welcome other criticisms and suggestions. We invite you to join with us in this project. 相似文献
73.
This article outlines the methodology and results of the Department of the Environment, Transport and the Regions (DETR) 1996-based household projections for England, and its regions. It examines differences between this round of projections and the previous 1992-based round. The 1996-based projections indicate that between 1996 and 2021 a growth of 3.8 million households can be expected in England, if recent trends continue. Both the national and subnational methodology and results are covered. 相似文献
74.
Insect communication: 'no entry' signal in ant foraging 总被引:1,自引:0,他引:1
Forager ants lay attractive trail pheromones to guide nestmates to food, but the effectiveness of foraging networks might be improved if pheromones could also be used to repel foragers from unrewarding routes. Here we present empirical evidence for such a negative trail pheromone, deployed by Pharaoh's ants (Monomorium pharaonis) as a 'no entry' signal to mark an unrewarding foraging path. This finding constitutes another example of the sophisticated control mechanisms used in self-organized ant colonies. 相似文献
75.
Farmer H McCabe N Lord CJ Tutt AN Johnson DA Richardson TB Santarosa M Dillon KJ Hickson I Knights C Martin NM Jackson SP Smith GC Ashworth A 《Nature》2005,434(7035):917-921
BRCA1 and BRCA2 are important for DNA double-strand break repair by homologous recombination, and mutations in these genes predispose to breast and other cancers. Poly(ADP-ribose) polymerase (PARP) is an enzyme involved in base excision repair, a key pathway in the repair of DNA single-strand breaks. We show here that BRCA1 or BRCA2 dysfunction unexpectedly and profoundly sensitizes cells to the inhibition of PARP enzymatic activity, resulting in chromosomal instability, cell cycle arrest and subsequent apoptosis. This seems to be because the inhibition of PARP leads to the persistence of DNA lesions normally repaired by homologous recombination. These results illustrate how different pathways cooperate to repair damage, and suggest that the targeted inhibition of particular DNA repair pathways may allow the design of specific and less toxic therapies for cancer. 相似文献
76.
Ethylene, the natural regulator of leaf abscission 总被引:1,自引:0,他引:1
Natural leaf fall is triggered by increased ethylene production in senescing cells close to abscission zones. 相似文献
77.
Résumé L'augmentation du fluide du tissu de l'intestin grèle incubé in vitro s'accompagne d'un accroissement du volume des cellules épithéliales. 相似文献
78.
R. Philo A. S. Berkowitz F. L. Jackson J. A. Lloyd J. P. Preslock 《Cellular and molecular life sciences : CMLS》1980,36(12):1425-1426
Summary Procedures designed to express pineal-mediated antigonadotropic activity were performed upon male house mice. Neither blinding nor blinding plus olfactory bulbectomy of house mice resulted in testicular involution within 12 weeks. The pineal gland appears to be of little significance to reproduction in the house mouse.Supported by NICHHD grant No. HDO 7119-092.Supported by NICHHD grant No. 5P5 OHDO 8338.Supported by NSF grant No. SPI 7922 372. 相似文献
79.
80.
Scanning electron microscope studies of human trabecular bone 总被引:1,自引:0,他引:1