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SUMMARY Clinical signs of proliferative haemorrhagic enteropathy (PHE) including anaemia, dysentery and sudden death were observed in finisher pigs and young breeding stock on 2 farms. On farm A, PHE occurred 12 months after repopulation of the farm. Other outbreaks of PHE occurred after the withdrawal of therapeutic concentrations of in-feed antibacterial agents (farm A), or after monensin sodium (100 g/t) replaced olaquindox (100 g/t) in feed (farm B). The outbreaks, the possible sources of contamination and the role of antibacterial feed additives in the treatment and control of PHE are described. 相似文献
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G Elamaran KP Singh MK Singh SK Singla MS Chauhan RS Manik P Palta 《Reproduction in domestic animals》2012,47(6):1027-1036
This study examined the effects of O2 concentration (5% vs 20%) during in vitro maturation (IVM), fertilization (IVF) and culture (IVC) or supplementation of IVM and IVC media with cysteamine (50 and 100 μm , respectively; IVM, IVF and IVC carried out in 20% O2), on blastocyst rate and relative mRNA abundance of some apoptosis‐related genes measured by real‐time qPCR in immature and in vitro‐matured buffalo oocytes and in embryos at 2‐, 4‐, 8‐ to 16‐cell, morula and blastocyst stages. The blastocyst rate was significantly higher (p < 0.05) while the percentage of TUNEL‐positive cells was significantly lower (p < 0.05) under 5% O2 than that under 20% O2. The mRNA expression of anti‐apoptotic genes BCL‐2 and MCL‐1 was significantly higher (p < 0.05) and that of pro‐apoptotic genes BAX and BID was lower (p < 0.05) under 5% O2 than that under 20% O2 concentration at many embryonic stages. Following cysteamine supplementation, the blastocyst rate and the relative mRNA abundance of BCL‐XL and MCL‐1 was significantly higher (p < 0.05) and that of BAX but not BID was lower (p < 0.05) at many stages of embryonic development, although it did not affect the percentage of TUNEL positive cells in the blastocysts significantly. The mRNA expression pattern of these genes during embryonic development was different in 5% vs 20% O2 groups and in cysteamine supplemented vs controls. At the 8‐ to 16‐cell stage, where developmental block occurs in buffalo, the relative mRNA abundance of BCL‐2 and MCL‐1 was highest under 5% O2 concentration and that of BAX and BID was highest (p < 0.05) under 20% O2 concentration. These results suggest that one of the mechanisms through which beneficial effects of low O2 concentration and cysteamine supplementation are mediated during in vitro embryo production is through an increase in the expression of anti‐apoptotic and a decrease in the expression of pro‐apoptotic genes. 相似文献
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Lushani Nanayakkara Elizabeth R. Starks Ryan N. Cooper Sydney Chow Peter R. Leavitt Björn Wissel 《Fisheries Management and Ecology》2021,28(1):18-27
This study evaluated the status of native and stocked fish species in 13 prairie lakes in central Canada over eight years (2007–14) using three metrics: resource-use (benthic versus pelagic carbon via stable isotopes); body condition (relative weight index Wr); and parasite load (cestode gut enumerations). Analyses included game and non-game fishes, like naturally occurring northern pike, Esox lucius L., and yellow perch, Perca flavescens Mitchill, but focused on stocked walleye, Sander vitreus (Mitchill) because it supports a robust recreational fishery. Walleye and northern pike were significantly more reliant on benthic carbon than yellow perch or forage fishes (p < 0.05), but this reliance was not associated with any measured environmental variables for any species. In lakes with game fishes, forage fishes exhibited higher reliance on benthic energy, possibly due to predator avoidance strategy, particularly yellow perch. Walleye body condition index was consistently lower (<95–105) than values exhibited by the other two game fishes (81–139), and parasites were only common in walleye and associated with lake-water salinity (r2 = 0.93, p < 0.05) and sex (p < 0.05). Based on the results, the most desirable game fish, walleye, appears less resilient to environmental variability than northern pike and yellow perch, making this species more susceptible to impacts of future climate change. 相似文献
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Dendritic cells (DCs) are a heterogeneous population of cells of fundamental importance in initiating innate as well as specific immune responses. The identity and function of DCs in the cat are unknown, although they are likely pivotal in the response to infection. In this study, feline DCs were derived by 3-10-day culture of adherent blood mononuclear cells (PBMCs) and bone marrow mononuclear cells (BMMCs) in the presence of IL 4 and GM-CSF. BMMC consistently yielded a greater number of DCs than PBMC, and there were fewer macrophages than DC from both compartments. DCs expressed a distinct constellation of surface molecules, which included CD1a, CD1b, and CD1c, CD11b, CD14, and 2-3-fold higher levels of MHC class I and II molecules than co-cultured macrophages or fresh blood monocytes. DCs displayed typical cytoplasmic processes, limited non-specific esterase activity, and acquired antigen by phagocytosis, pinocytosis, and binding to specific receptors. Cytokine-exposed cells induced proliferation of allogeneic lymphocytes. Thus, the cells derived by these culture conditions had markers and functions analogous to immature myeloid DCs. Availability of feline DCs will enable investigation of their role in infectious disease and their potential therapeutic application. 相似文献
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对松狮这个品种情有独钟的人一定知道美国最顶尖的松狮犬舍之——Imagine犬舍,美国国家认可的松狮俱乐部等级中首屈一指的犬舍。他们的松狮犬以帝王的外形、健全的身体和头脑而著称。Imagine犬舍坐落在美国南加州的圣贝纳迪诺山脚下,松树、桉树、棕榈树与盛开的丝兰和仙人掌围绕着他们美丽的家园,不远处就是积雪覆盖的山脉,绿、蓝、白的交会,组成了—幅美丽的画面。而对于犬舍主理人Kathy Beliew女士和她的丈夫George,更是广大松狮迷眼中偶像级的人物。 相似文献
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An immersion technique for studying wood wettability 总被引:1,自引:1,他引:1
Summary The wetting properties of wood were studied by a modification of the Wilhelmy technique. This method involved continuously monitoring the force exerted on a wood specimen as it was immersed at a controlled rate into a liquid. Wettability was expressed in terms of the area under the force-immersion curve and was referred to in this study as wettability index. The applicability of the technique was demonstrated for padauk and white spruce wood specimens heated for various time periods. The wettability of these woods in both distilled water and sodium hydroxide solutions decreased with increasing heating time. Sodium hydroxide solution yielded higher wettability index values, indicating that it was a better wetting agent than distilled water. The pH of the sodium hydroxide solution had a strong influence on magnitude of the wettability index. The possibility of using the technique for examining wood surface inactivation in relation to bonding with different adhesives is discussed.The authors gratefully acknowledge the assistance of Dr. W. G. Warren and his staff for the statistical analyses and curve fitting. Dr. Casilla also expresses his gratitude to the National Research Council of Canada and to the Canadian Forestry Service, Department of the Environment, for a postdoctoral fellowship 相似文献
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Jeffrey Chow 《Journal of Sustainable Forestry》2015,34(6-7):651-681
Mangroves worldwide provide a wide range of ecosystem services utilized directly and indirectly by local peoples. Between 1966 and 2001, Bangladesh established approximately 148,000 ha of mangrove plantations in coastal areas within the Barisal and Chittagong Divisions. Though erosion and human encroachment and conversion have removed over two-thirds of these stands, the Forest Department has continued to undertake new plantation activities.To investigate how and to what degree people directly utilize these mangroves, I conducted 340 household surveys across eight coastal villages located in close proximity to established plantations. The predominant direct use of the mangrove plantations by local rural communities is the extraction of detritus and nonmain stem material (e.g., limbs, leaves) for combustible fuel. This study uses household foraging distances to estimate and map net value densities based on reported market prices of extracted goods. The average extractive value of mangrove plantations is Tk 2,300 ha?1 yr?1, ranging among the villages from 300 to Tk 27,400 ha?1 yr?1, with values concentrated closer to the village. Cost-benefit analyses suggest that direct use values alone have justified the establishment and management of previously planted stands. However, other indirect values must be taken into account if these areas are to merit additional plantations. 相似文献