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Animal rights and experimentation have become the focus of a major controversy in the United States, with acute implications for animal-related research in the laboratories and veterinary schools of many American universities. To date, efforts to reduce fundamental disagreements between animal researchers and animal welfare groups or to redefine their differences in ways that satisfy all concerned have by and large not been successful. In such situations where it is not possible to identify a middle ground between conflicting positions, the best a policy analyst may be able to do is to accentuate the issue's manifest topsy-turviness and uncertainties. No one can afford or risk having an issue of such high uncertainty, inconsistency, and stakes defined in terms so stark that they feel compelled to choose between those who say they know that the future shall hold us accountable for our wholesale slaughter of animals and those who would blame us for the human deaths they say will surely follow when we do not allow that slaughter.Emery Roe is a senior administrative analyst in the University of California's Office of Research and Public Policy and has a postdoctoral fellowship in resource economics at the University's Berkeley campus. He has published widely on agricultural, livestock, and environmental issues in the U.S. and Africa.  相似文献   
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AIM: To describe the pathology and inheritance of a congenital polycystic kidney disease (PKD) of sheep.

METHODS: Mode of inheritance of PKD was investigated by evaluation of results of the disorder from planned matings in two consecutive years within subsets of a flock that had a high prevalence of PKD in lambs. Gross pathological and histopath- ological studies were based on tissues derived from this study. Haematoxylin and eosin (H&E)-stained paraffin sections of kidney, liver, extrahepatic biliary and pancreatic ducts, pancreas and epididymis were used to describe the lesions.

RESULTS: Twenty-five lambs affected by PKD, of both sexes, were born, numbers in accord with those expected for an autosomal recessive disorder in the population studied. In all cases for which tissues were available, the renal, bile ductal (intrahepatic and extrahepatic), pancreatic and epididymal tissues had widespread dysplastic changes and associated cyst formation.

CONCLUSIONS: The findings of renal cysts in conjunction with cysts in other organs are unifying features in many of the human and animal forms of PKD and suggest a related pathogenic and genetic base consistent with an autosomal recessive disorder.  相似文献   
125.
Novel acylpyridinium salt chemistry and directed lithiation methodology was developed to add for the first time substitutions directly to the phenylpyridine heterocyclic ring of nicotine. A variety of 3-(1-methylpyrrolidin-2-yl)-4-(alkyl, aromatic, heterocyclic and silanyl) and -N-alkyl pyridines were synthesized (compounds 1-9). In vial tests with the green peach aphid, Myzus persicae, compounds 1-4 were 1.1, 1.8, 2.3 and 1.9×, respectively, more active than nicotine and 64, 40, 31 and 38×, respectively, less active than acetamiprid. Against the western flower thrips, Frankliniella occidentalis, 1-4 were 1.4, 2.1, 2.0 and 1.6×, respectively, more active than nicotine and 9, 6, 6 and 8×, respectively, less active than acetamiprid. For the cotton aphid, Aphis gossypii, the activity of 1-9 was similar to nicotine. Compounds 7 and 9 when incorporated into artificial diet produced low mortality for larvae of the beet armyworm, Spodoptera exigua, but were not active against the corn earworm, Helicoverpa zea. When 1-4 and 6-9 were injected into larvae of the beet armyworm, a variety of symptoms similar to acetamiprid were observed which included tremors, uncoordinated movement, diuresis, paralysis and death. In addition, imidacloprid-binding to membranes from the house fly head, Musca domestica, was inhibited by compounds 1-9, when using a concentration range of 1-100 μM. These studies demonstrate that our new chemistry enhances the insecticidal activity of nicotine with an apparent mode of action as an acetylcholine agonist.  相似文献   
126.
Observations of Titan's mid-latitude clouds from the W. M. Keck and Gemini Observatories show that they cluster near 350 degrees W longitude, 40 degrees S latitude. These clouds cannot be explained by a seasonal shift in global circulation and thus presumably reflect a mechanism on Titan such as geysering or cryovolcanism in this region. The rate of volatile release necessary to trigger cloud formation could easily supply enough methane to balance the loss to photolysis in the upper atmosphere.  相似文献   
127.
Legumes form symbiotic associations with both mycorrhizal fungi and nitrogen-fixing soil bacteria called rhizobia. Several of the plant genes required for transduction of rhizobial signals, the Nod factors, are also necessary for mycorrhizal symbiosis. Here, we describe the cloning and characterization of one such gene from the legume Medicago truncatula. The DMI1 (does not make infections) gene encodes a novel protein with low global similarity to a ligand-gated cation channel domain of archaea. The protein is highly conserved in angiosperms and ancestral to land plants. We suggest that DMI1 represents an ancient plant-specific innovation, potentially enabling mycorrhizal associations.  相似文献   
128.
The effect of heat stable and heat labile Escherichia coli enterotoxins or cholera toxin in combination with theophylline on net water, sodium and chloride and unidirectional sodium and chloride fluxes was examined in acute isolated loops of jejunum of weanling swine. The effect of heat stable enterotoxin in combination with theophylline was determined in loops located in the proximal jejunum, while combinations of theophylline and either heat labile enterotoxin or cholera toxin were studied in the distal jejunum. In each situation the addition of theophylline resulted in an additive rather than a synergistic increment of intestinal secretory activity. This study implies that the intestinal adenyl cyclase system and enterotoxin induced intestinal secretion may not be directly related in the swine small intestine.  相似文献   
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Receiver functions derived from teleseismic body waves recorded by ocean-bottom seismometers on the southern East Pacific Rise reveal shear waves converted from compressional waves at the mantle discontinuities near 410- and 660-kilometer depth. The thickness of the mantle transition zone between the two discontinuities is normal relative to the global average and indicates that upwelling beneath the southern East Pacific Rise is not associated with an excess temperature in the mantle transition zone.  相似文献   
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