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Hematologic and/or serum chemical analyses were done on a total of 27 non-tranquilized adult and juvenile wild sea otters, 66 tranquilized adult and juvenile wild sea otters, and 26 wild sea otter pups. The median and inner 90 percentile range were determined for the adult, juvenile, and pup groups and for the following subgroups: adult male versus adult female, juvenile male versus juvenile female, pup male versus pup female, captured with dip net versus captured with Wilson trap, and tranquilized adults and juveniles versus non-tranquilized adults and juveniles. When values for adults were compared to values for juveniles and pups, hematocrits, red blood cell counts, and hemoglobin levels were significantly lower in pups. This is consistent with documented findings in other species. White cell counts were also somewhat lower in younger animals. Among the subgroups, significantly higher hemoglobin levels, white cell counts and neutrophil counts were found in adult females than in adult males. This is in direct contrast to what is seen in other mammalian species and warrants further documentation. Method of capture and tranquilization did not appear to influence either hematologic or serum biochemical determinations from a clinical perspective.  相似文献   
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Plant resistance to insect herbivory involves gene expression in response to wounding and the detection of insect elicitors in oral secretions (Kessler and Baldwin, 2002, Ann. Rev. Plant/ Biol. 53: 299–328). However, crawling insect larvae stimulate the synthesis of 4-aminobutyrate within minutes and imprints of larval footsteps can be visualized within seconds through superoxide production or transient increases in chlorophyll fluorescence (Bown et al., 2002, Plant Physiol. 129: 1430–1434). Here cryo-scanning electron microscopy was used to demonstrate that larval feet, which are equipped with a perimeter row of hook-like crochets, damage leaf tissue and result in larval footprints. Staining for cell death shows that areas of wounding correspond to footsteps detected through increased chlorophyll fluorescence. Superoxide production in response to footsteps was inhibited by diphenyleneiodonium, an inhibitor of the plasma membrane NADPH oxidase enzyme. Inhibition of superoxide production, however, did not eliminate the detection of cell death. The results demonstrate that larval footsteps damage leaf tissue, and initiate rapid local responses which are not dependent on herbivory or oral secretions. It is proposed that superoxide production at the wound site prevents opportunistic pathogen infection.  相似文献   
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Sugarcane management systems affect soil attributes such as the carbon cycle. This fact has stimulated the sugar and alcohol industry to refine the sugarcane production systems by replacing the pre-harvest burning (PB) and manual harvest with mechanized harvesting followed by residue deposition. The aim of this study was to evaluate different management systems with respect to C cycling carbon dioxide and soil parameters (chemical, physical and biological) which were determined over the season. Three sugarcane cultivation systems were evaluated at the following periods: (a) PB, (b) 5-year green harvest and (c) 10-year green harvest. The results indicated that CO2 emission was 36% greater in the 10-year sugarcane green harvest system than in the PB system. The bulk density and macroporosity were the factors that were most affected by the different sugarcane management systems and that significantly influenced soil CO2 emissions. The principal component analysis showed that soil CO2 emission was 18% influenced by base saturation (V%) and 14% by pH, especially in the PB area. Additionally, 19% was affected by carbon and macroporosity in the 5- and 10-year green harvest areas, respectively. From our results, it can be concluded that the most CO2 emissions are in the areas of sugarcane green, this is due to the higher carbon concentration when compared with the area of burning sugarcane. The parameters that most influenced the CO2 emissions were bulk density, porosity, macroporosity, pH and V%.  相似文献   
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Chiral compounds account for 25% of all agrochemical compounds used commercially and for 26% of the total value of the world agrochemical market. However, those sold in single isomer form contribute only 7% to the market value despite many potential advantages in terms of regulatory, intellectual property and marketing benefits. Limited access to chiral raw materials and economic synthesis routes are key reasons why single isomers are less common than they might be. The development of more chiral routes will encourage the development of single isomer compounds to capitalise on their advantages.  相似文献   
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• Livestock production in North America has moved to fewer farms with greater inventories • Land application of livestock manures is a preferred nutrient recycling strategy • Confined animal feeding operations have challenges to utilize livestock manure sustainably • Integration of livestock and cropping systems is possible on a farm or among farms • Nutrient balance is needed for environmental sustainability Livestock production in the United States (US) and Canada is diverse, but shows a common trend in most livestock sectors toward fewer farms producing the majority of animal products despite a large number of farms still small in production scale. The migration to larger and more concentrated animal feeding operations in beef finishing and poultry, swine, and dairy production allows processors to streamline supplies to meet market demand for abundant, low-cost livestock products, whether that be for packaged meat, dairy products, or eggs. With concentration of livestock operations comes the challenge of managing manures. When sufficient land is available and nutrients are needed, livestock manure is an excellent nutrient source and land application is the preferred method of recycling this resource. However, when livestock production is constrained in a geographical area and animal densities are high, manure may become an environmental liability with potentially greater risk for runoff and leaching of nutrients, emission of odors, ammonia, and greenhouse gases, and release to the environment of pathogens and chemicals of emerging concern. Addressing these challenges now and into the future requires learning from mistakes and adopting successful approaches. We describe different levels of integration between livestock and crop producers in New York, British Columbia, and the south-eastern US as learning opportunities to improve economic and environmental sustainability. Examples show that effective solutions should recognize (1) manure has value and is not just a cost, (2) farmers, farm advisors, extension educators, nutrient management planners, crop advisors, nutritionists, state agency personnel, regulators, and university researchers need to be active participants in development of solutions, and (3) change to a sustainable future requires a combination of government regulation and outcome-based incentives.  相似文献   
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