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991.
It is well-known that modelers and policy analysts gain access to policymaking arenas based on what they know. Therefore, critics of models are quick to employ various types of technical standards when evaluating policy models in order to assess validity and reliability of claims to knowledge. This article argues that, in the effort to make models better, overreliance on technical standards misses the important political and policy reasons to model: models call attention to the modelers and to their advice about important policy problems of the day. In this sense, models are used as symbols, as claims to authority, whether or not the underlying knowledge is technically up to snuff. Drawing on the experience of energy policy models, this article explores the problem of models as knowledge versus models as symbols and it examines the muddle that conflicts between them produce.  相似文献   
992.
The absorption-elution technique with low ionic strength solution (LISS) and papain-treated test cells previously used for bloodstains was employed for the detection of ABO antigens on human hair. Antigen identification was always possible, with good intensity of agglutination, even in those cases where classic techniques had given false-negative results. It was possible to obtain positive results with fragments of human hair as small as 0.2 cm.  相似文献   
993.
The sensitivity and specificity of a zinc spot test for the detection of semen were compared with those of an acid phosphatase detection method. As screening techniques both tests were found to be very sensitive, but the zinc test was more specific and was more reliable in older and especially in deteriorated specimens. It is concluded that the zinc spot test deserves at least the same place as the acid phosphatase test in the primary investigation of suspected semen stains and might well be the test of choice in older and poorly preserved stains.  相似文献   
994.
An animal model was designed to evaluate the ability of the standard military flak jacket to protect the kidneys from direct ballistic trauma. Yorkshire swine were anesthetized and their flanks were protected by flak jackets. Ballistic insults ranging from a low-velocity handgun to a high-velocity rifle were evaluated. The results demonstrate that a flak jacket provides adequate protection against low- and mid-velocity projectiles since none of the animals from this group had evidence of internal trauma and because only minor superficial surgical attention would have been required. Survivability in each case was considered to be excellent. The flak jacket failed to provide any protection against several types of high-velocity bullets. These weapons caused severe internal injury to the genitourinary system as well as to other major organ systems. Survival would have been unlikely.  相似文献   
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