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71.
72.
Nancy Grudens-Schuck Will Allen Tasha M. Hargrove Margaret Kilvington 《Agriculture and Human Values》2003,20(1):53-64
Dependency stands for manygrievances and is generally considered asymptom of oppression. An opposing concept,offered as the preferred state, isself-reliance. Dependency and self-reliance arekey concepts in sustainable developmentprograms that feature participatory approaches.Some of the ways in which development projectsemploy the concepts of dependency andself-reliance, however, are troubling.Dependency and self-reliance in two programsfor participatory sustainable development areexamined, one in Canada and the other in NewZealand. Frameworks for dependency and self-reliance aredrawn from social psychology and philosophy toexamine problematic aspects associated with theconcepts. Analysis produced a proposal foruse of the term situatedinterdependence as a way to cast the outcomesof participatory sustainable development moreprecisely. The location of the cases (Canadaand New Zealand) centers the discussion withina context of industrialized agriculture, butalso points to issues pertinent to developingcountries. 相似文献
73.
Impacts of anthropogenic N additions on nitrogen mineralization from plant litter in exotic annual grasslands 总被引:1,自引:0,他引:1
Urban regions of southern California receive up to 45 kg N ha-1 y-1 from nitrogen (N) deposition. A field decomposition study was done using 15N-labelled litter of the widespread exotic annual grass Bromus diandrus to determine whether elevated soil N is strictly from N deposition or whether N mineralization rates from litter are also increased under N deposition. Tissue N and lignin concentrations, which are inversely related in field sites with high and low N deposition, determine the rate at which N moves from plant litter to soil and becomes available to plants. The effect of soil N on N movement from litter to soil was tested by placing litter on high and low N soil in a factorial experiment with two levels of litter N and two levels of soil N. The litter quality changes associated with N deposition resulted in faster rates of N cycling from litter to soil. Concentrations of litter-derived N in total N, NH4+, NO3−, microbial N and organic N were all higher from high N/low lignin litter than from low N/high lignin litter. Litter contributed more N to soil NH4+ and microbial N in high N than low N soil. At the end of the study, N mineralized from high N litter on high N soil accounted for 46% of soil NH4+ and 11% of soil NO3−, compared to 35% of soil NH4+ and 6% of soil NO3− from low N litter on low N soil. The study showed that in high N deposition areas, elevated inorganic soil N concentrations at the end of the summer N deposition season are a result of N mineralized from plant litter as well as from N deposition. 相似文献
74.
Conjunctivitis, tracheitis, and pneumonia associated with herpesvirus infection in green sea turtles 总被引:3,自引:0,他引:3
E R Jacobson J M Gaskin M Roelke E C Greiner J Allen 《Journal of the American Veterinary Medical Association》1986,189(9):1020-1023
Fourteen juvenile (15- to 20-month-old) green sea turtles (Chelonia mydas), representative of a group of sea turtles with clinical signs of respiratory tract disease, were euthanatized and submitted for necropsy. Macroscopically, lesions included periglottal necrosis, tracheitis with intraluminal caseous and laminated necrotic debris, and severe pneumonia. Several turtles had caseous conjunctival exudate covering the eyes. Microscopically, the turtles had fibrinonecrotic inflammation around the glottal opening, tracheitis, and severe bronchopneumonia and interstitial pneumonia. In multifocal areas, periglottal and tracheal epithelial cells adjacent to areas of necrosis had hypertrophic nuclei with amphophilic intranuclear inclusions. A mixed population of primarily gram-negative microorganisms was isolated from the tracheal and glottal lesions. Attempts at viral isolation in cultures of green sea turtle kidney cells resulted in the development of cytopathic effects characterized by giant cell formation and development of intranuclear inclusions. Using electron microscopy, intranuclear viral particles (88 to 99 nm in diameter) were seen in inclusion-containing tracheal and glottal epithelial cells and infected green sea turtle kidney cells; particles were consistently seen enveloping from nuclear membranes, and mature particles (132 to 147 nm) were found in the cytoplasm. On the basis of size, conformation, location, and presence of an envelope, the particles most closely resembled those of herpes-viruses. 相似文献
75.
Fontaine GL Belknap JK Allen D Moore JN Kroll DL 《American journal of veterinary research》2001,62(5):714-720
OBJECTIVE: To study expression of interleukin-1beta (IL-1beta) in the digital laminae of horses in the prodromal stage of experimentally induced laminitis. ANIMALS: 8 healthy adult horses with no signs of laminitis. PROCEDURES: Black walnut extract was administered via nasogastric tube to 4 horses, and water was administered to the remaining 4 (controls). Complete blood counts and physical examinations were performed every 30 minutes after administration of black walnut extract or water. General anesthesia was induced when total WBC count decreased by 30% in horses given the black walnut extract and 3 hours after water administration in control horses. The left forefoot was perfusion fixed with neutral-buffered 10% formalin, and paraffin-embedded sections of the digit were used for in situ hybridization with an equine-specific IL-1beta probe. RESULTS: IL-1beta mRNA expression was observed in perivascular cells of the small laminar venules and capillaries in all 4 horses given black walnut extract and in interstitial cells remote from the microvasculature in 1 of the 4. Other cellular components of the laminar tissue and cellular components of the digital arterioles and veins did not exhibit IL-1beta mRNA expression. Expression of IL-1beta mRNA was not detected in laminae from control horses. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that IL-1beta mRNA is expressed by perivascular cells in the laminar tissues of horses in the prodromal stage of experimentally induced laminitis. This provides evidence of an inflammatory process during the prodromal stage of laminitis, indicating that local digital proinflammatory cytokine expression may be an initiating factor in laminitis. 相似文献
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79.
Studies on canine pregnancy using B-mode ultrasound: Development of the conceptus and determination of gestational age 总被引:3,自引:0,他引:3
G.C.W. England W. Edward Allen D. J. Porter 《The Journal of small animal practice》1990,31(7):324-329
Development of the conceptus was characterised using B-mode ultrasound in a standard size of dog (labrador retrievers, golden retrievers and their crosses; weight range 22 to 30 kg). Growth curves were established for various measurements of the conceptuses. Regression equations allowed the prediction of the expected time of parturition. Multiple regression analysis of two measurements (biparietal diameter and trunk diameter) resulted in an increase in the confidence of prediction. 相似文献
80.
B K Knudson M G Hogberg R A Merkel R E Allen W T Magee 《Journal of animal science》1985,61(4):797-801
Differences in total carcass bone, muscle and fat, and linear measurements of the tibia and radius were evaluated in barrows at 105 kg and boars at 105, 118, 132 and 145 kg live body weight. The carcasses of five replicates were physically separated into skin, bone and soft tissues, and the linear measurements of the tibia and radius were obtained on seven replicates. At live weight of 105 kg, boars did not differ significantly in fat-free muscle, but they had 33.2% less fat, 11% greater bone weight and 14% greater skin weight than barrows. At 145 kg, boars had total carcass fat weight comparable with 105-kg barrows. Fat-free muscle, bone and skin weight of boars increased at linear rates of .41, .083 and .104 kg/kg of body weight increase from 105 to 145 kg, respectively. At 105 kg, density and length of the tibia and radius did not differ between boars and barrows. The tibia of boars were heavier than those of barrows at 105 kg, resulting in a greater ratio of tibia weight to length (indirect measure of bone thickness). As boars increased in live weight from 105 to 145 kg, total weight and length of the tibia and radius increased linearly. The ratio of weight to length of the tibia and radius increased during this 40-kg weight gain, indicating that weight of both bones increased at a greater rate than length. These results indicate that boars and barrows have the same weight of total carcass fat when boars are 40 kg heavier than the barrows. The greater bone weight of boar carcasses compared with barrows is due to greater bone thickness. 相似文献