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951.
Exploring the possibilities for commercial aquaculture has historically concentrated on reducing production uncertainty by focusing on an animal's biology and the engineering of the production facility. However, the aquaculturist faces both production and market uncertainty, both of which may significantly affect the economic feasibility of a production facility. We developed a dynamic stochastic model to compare alternative production and marketing scenarios and used the net present value of returns to evaluate the scenarios. Based on the model and the scenarios we examined, firms producing summer flounder Paralichthys dentatus are unlikely to be profitable unless they locate near and use a source of salt-water, sell their product predominately to sushi chefs (or other premium market outlets) who desire medium-sized live fish, and engage in strategies that account for market dynamics. 相似文献
952.
953.
954.
Jiwan P Palta 《Potato Research》2010,53(4):267-275
Calcium plays a major role in plant growth and development and in the maintenance and modulation of various cell functions,
especially related to membrane structure and function and to cell wall structure. Calcium stabilizes cell membranes by bridging
polar head groups of phospholipids at the membrane surface. Calcium is also an integral part of the cell wall where it provides
stable intra-molecular linkages between pectin molecules, resulting in cell wall rigidity. A change in the cytosolic calcium
concentration is also known to provide a cellular signal that regulates metabolism and mediates plant responses to stresses. 相似文献
955.
Kimihiko Hyakumura 《Small-Scale Forestry》2010,9(3):349-367
A progressive part of protected area management program in Lao PDR is a land and forest allocation program which contains
critical elements that delegate right of land and forest use to local people. This study analyzes the gap between the original
intent of the program and its actual implementation by local officials in Phou Xang He protected area, and discusses policy
issues that need to be addressed. It appears that several types of non-compliance with regulations by local people have occurred,
with local officials tacitly ignoring infractions. By switching viewpoints, however, it appears that the local officials permit
these infractions as a way of allowing local people to secure their livelihoods. As constraints on the realities of land and
forest use vary widely in and around villages in different locales, there is a need for government to allow local officials
flexibility in implementing policies. 相似文献
956.
Margaret A Miller José A Ramos-Vara Mary F Dickerson Gayle C Johnson Lanny W Pace John M Kreeger Susan E Turnquist James R Turk 《Journal of veterinary diagnostic investigation》2003,15(6):515-522
Thirteen uterine tumors were diagnosed in 13 cats and accounted for 0.29% of all feline neoplasms received during a 9.6-year period. Age at diagnosis ranged from 3 to 16 years; median 9 years. Six were Domestic Shorthair cats, and 7 were purebred cats of 5 different breeds. Eight adenocarcinomas and 1 mixed Müllerian tumor (adenosarcoma) comprised the endometrial tumors. Myometrial tumors included 3 leiomyomas and 1 leiomyosarcoma. One of the adenocarcinomas developed in the uterine stump of an ovariohysterectomized cat; the other cats were sexually intact. Concurrent mammary adenocarcinoma was diagnosed in 1 cat with uterine adenocarcinoma and in another with uterine leiomyoma. Tumors were discovered during elective ovariohysterectomy in 2 cats, but at least 3 others had experienced reproductive problems (infertility or pyometra). Five cats presented for abdominal or pelvic masses. Endometrial adenocarcinomas were positive immunohistochemically for cytokeratins and negative for smooth muscle actin (SMA): 1 of 6 cats was positive for vimentin and 4 of 8 were positive for estrogen receptor-alpha (ER alpha). Adenosarcoma stromal cells were positive for vimentin and ER alpha but negative for cytokeratins and SMA. Smooth muscle tumors were positive for vimentin and SMA and negative for cytokeratins. Leiomyomas, but not the leiomyosarcomas, were positive for ER alpha. Adenocarcinomas in 4 cats had metastasized by the time of ovariohysterectomy. Two other cats were euthanized 5 months after ovariohysterectomy; at least one of these cats had developed an abdominal mass that was not examined histologically. Only 2 cats with endometrial adenocarcinoma had disease-free intervals longer than 5 months after surgery. Metastasis was not detected in any mesenchymal tumor; however, these cats were either euthanized on discovery of the tumor or the tumor was first detected at necropsy. 相似文献
957.
James H. Tidwell Shawn D. Coyle Leigh Anne Bright David Yasharian 《Journal of the World Aquaculture Society》2005,36(4):454-463
Two feeding trials were conducted with juvenile largemouth bass Micropterus salmoides to evaluate alternative plant and animal source proteins for their ability to replace fish meal in practical diets. The first trial was designed to identify the most promising candidates. The second trial was conducted to evaluate how much of the fish meal could be replaced by those candidates. In Study 1, feed‐trained largemouth bass (3.1 ± 0.7 g) were randomly stocked into 18114‐L glass aquaria at 25 fish per aquarium. Fish were fed one of six experimental diets, each containing approximately 38% crude protein and 10% crude lipid, to apparent satiation twice daily. The control diet (CTL) contained 30% fish meal and 34.5% soybean meal. Diets 2–6 each contained 15% fish meal and at least 34.5% soybean meal with the remainder of the protein made up of either meat and bone meal (MBM), soybean meal (SBM), poultry by‐product meal (PBM), a 50150 mixture of blood meal and corn gluten meal (BM/CG), or 50150 mixture of hydrolyzed feather meal and soybean meal (FMISBM). There were three replicate aquaria per dietary treatment. After 12 wk, there was no significant difference (P > 0.05) among treatments in survival which averaged 92% overall. Only fish fed the PBM or BM/CG diets had average individual weights and feed conversion efficiencies that were not significantly different (P > 0.05) from the control diet (CTL). In Study 2, the formulation of the control diet (CTL) remained the same. Based on their performance in the first trial, PBM and BM/CG were chosen to now replace 75 or 100% of the fish meal. Fish were stocked at an average weight of 6.9 ± 1.7 g. After 11 wk, fish fed diets containing the BM/CG mixture at both levels were significantly smaller (P 5 0.05) than fish fed other diets and at 100% replacement survival was reduced. Fish fed diets containing poultry meal as the primary protein source performed as well as those fed the control diet (CTL). It appears that PBM can completely replace fish meal in diets for juvenile largemouth bass without adverse effects on growth, feed efficiency, or body composition. 相似文献
958.
Scott R. McClure DVM James Schumacher DVM MS Earl L. Morris DVM MS 《Veterinary radiology & ultrasound》1993,34(5):334-335
A 14-year-old Quarter Horse was presented for evaluation of a chronic, intermittent purulent discharge from the left nostril. A radioopaque mass and multiple, air-fluid interfaces in the paranasal sinuses were identified on survey radiographs. The mass was removed and identified as a dentigerous cyst. Substantiated reports of dentigerous cysts in the paranasal sinuses are rare. 相似文献
959.
James J England 《Veterinary Clinics of North America: Food Animal Practice》2002,18(3):373-8, v
Biosecurity is the management practice that reduces the opportunities for infectious agents to gain access to, or spread within, a food animal production unit. As the public's concern for food safety continues to be directed toward the producer, a well-defined and well-documented biosecurity plan will be a significant factor in ensuring that animal products are safe, wholesome, and acceptable. Veterinarians are the initial control point for biosecurity and therefore are expected by their clientele and the general public to assist in establishing, defining, refining, and practicing biosecurity programs. 相似文献
960.