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Wisent, or European bison (Bison bonasus), is listed as “vulnerable” on the IUCN Red List of Threatened Species and is therefore protected by international law. For the first time, a Wisent embryo has been obtained in vitro. This procedure creates a new opportunity to protect and increase Wisent reproductive potential and thereby opens new possibilities for the establishment of a controlled and broad reserve of the gene pool.  相似文献   
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Improving our understanding of the mechanisms controlling the corpus luteum (CL) and its role in regulating the reproductive cycle should lead to improvements in the sustainability of today's global animal industry. The corpus luteum (CL) is a transient endocrine organ composed of a heterogeneous mixture steroidogenic, endothelial and immune cells, and it is becoming clear that immune mechanisms play a key role in CL regulation especially in luteolysis. Toll‐like receptors (TLR) mediate innate immune mechanisms via the production of pro‐inflammatory cytokines, especially within various tissues, although the role of TLR within CL remains unknown. Thus, the objectives of this study were to characterize TLR mRNA expression in the CL during the oestrous cycle and in pregnancy (day 30–50), and to examine the role of TLR signalling in luteal cells. Corpora lutea were collected at various stages of the cycle and pregnancy and analysed for TLR and cytokine mRNA expression. In addition, luteal cells were cultured with the TLR4 ligand (lipopolysaccharide, LPS) for 24 h to evaluate the role of TLR4 in regulating luteal function. Toll‐like receptors 1, 2, 4, 6, tumour necrosis factor alpha (TNF), interferon gamma (IFN‐G), and interleukin (IL)‐12, mRNA expressions were greatest in regressing CL compared with earlier stages (p < .05), whereas no change was observed for IL‐6 mRNA expression. Cytokine mRNA expression in cultured luteal cells was not altered by LPS. Based on these data, one or more of the TLRs found within the CL may play a role in luteolysis, perhaps via pro‐inflammatory cytokine mRNA expression.  相似文献   
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Objective To determine whether dogs and cats are potential reservoirs of Ross River (RR) and Barmah Forest (BF) viruses
Method Young seronegative female dogs and cats were experimentally exposed to the viruses using Ochlerotatus vigilax (Skuse) mosquitoes.
Results Only one of the 10 dogs and one of the 10 cats exposed to RR developed neutralising antibody. None of the animals developed detectable viraemia or clinical signs. One dog and three cats exposed to BF developed neutralising antibody. In addition, a serological survey of sera obtained from domestic dogs and cats residing in the Brisbane region indicated that 23.7% and 1.3% of dogs, and 14% and 2% of cats, had neutralising antibodies to RR and BF respectively.
Conclusions Although dogs and cats are exposed naturally to these viruses, and can become infected, they are unlikely to be important urban reservoirs of either virus.  相似文献   
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泸州荔枝果园AM真菌菌根及孢子数量调查与分析   总被引:1,自引:0,他引:1  
[目的]对泸州荔枝园AM真菌进行调查,确认荔枝菌根类型,了解果园土壤中AM真菌孢子种群数量的大致情况。[方法]利用"湿筛法"和Phllips&Hayman的方法对3个泸州荔枝果园春季的土壤AM真菌进行了调查分析。[结果]荔枝菌根是内生菌根,共生真菌为囊泡——丛枝菌根真菌,即AM真菌。春季的菌根感染率在9%~32%之间,普遍低于25%。VA菌根感染率的平均值在15%~21%之间,低于25%。三个荔枝园每25 g土样中AM真菌孢子数平均值为869±76个。[结论]果园生草或对果园进行有机覆盖,是促进荔枝生长,增加荔枝果实产量,改善荔枝果实品质的一种绿色环保途径。  相似文献   
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Design of a surface alloy catalyst for steam reforming   总被引:1,自引:0,他引:1  
Detailed studies of elementary chemical processes on well-characterized single crystal surfaces have contributed substantially to the understanding of heterogeneous catalysis. Insight into the structure of surface alloys combined with an understanding of the relation between the surface composition and reactivity is shown to lead directly to new ideas for catalyst design. The feasibility of such an approach is illustrated by the synthesis, characterization, and tests of a high-surface area gold-nickel catalyst for steam reforming.  相似文献   
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An enzyme-linked immunosorbent assay (ELISA) was developed to measure total antibody to Toxoplasma gondii in serum samples from macropods. The validity of the assay was established by comparing parasite isolation in mice for 17 Tasmanian pademelons (Thylogale billardierii) and 17 Bennett's wallabies (Macropus rufogriseus rufogriseus). The ELISA was then used to detect antibody against T. gondii in serum from 236 macropods, collected from 21 locations in Tasmania, including Flinders Island. Antibody against T. gondii was detected in 20 animals (15 T. billardierii and 5 M. rufogriseus). There was a significant (p less than 0.01) difference in possession of T. gondii antibodies between adult (greater than or equal to 1 year of age) Tasmanian pademelons and Bennett's wallabies.  相似文献   
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