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991.
992.
993.
Juan A. García Mauricio A. Navarro Karina Fresneda Francisco A. Uzal 《Journal of veterinary diagnostic investigation》2022,34(3):421
Tyzzer disease (TD) is caused by Clostridium piliforme, a gram-negative and obligate intracellular bacterium. The disease occurs in multiple species. A triad of lesions, namely colitis, hepatitis, and myocarditis, is described in cases of TD in some species, such as rats and mice. We carried out a retrospective analysis of 25 equine cases with a diagnosis of TD; 24 of 25 cases occurred in foals <45 d old; the remaining foal was 90 d old. There were 12 males and 12 females; no sex information was available for one foal. The affected breeds were Quarter Horse, Thoroughbred, Arabian, Paint, and Hanoverian. Most of the cases (19 of 25) occurred in the spring. There were 9 cases of sudden death; the remaining animals had diarrhea, fever, distended abdomen, depression, weakness, non-responsiveness, and/or recumbency. Gross findings included icterus, hepatomegaly with acinar pattern, serosal hemorrhages, pulmonary edema, and/or fluid content in small and large intestine. Microscopically, all foals had severe, multifocal, necrotizing hepatitis. Necrotizing lymphohistiocytic colitis was observed in 10 of 25 foals, and multifocal necrotizing myocarditis was found in 8 of 25. Gram-negative, Steiner-positive, intracytoplasmic filamentous bacteria were observed in hepatocytes, enterocytes, and myocardiocytes, respectively. PCR detected C. piliforme DNA in the liver (24 of 24), colon (20 of 24), and heart (5 of 25). Our results indicate that necrotic hepatitis is the hallmark of TD in horses; the so-called triad of lesions is not a consistent characteristic of the disease in this species. 相似文献
994.
植物-土壤微生物反馈在草地演替过程中的作用机制 总被引:1,自引:0,他引:1
植物-土壤反馈影响生态系统结构、功能及过程,推动植物群落组成的变化,对解释植物群落的演替进程和方向、维持植物群落多样性和稳定性有着重要意义,已成为近年生物学和生态学研究热点。植物-土壤微生物反馈是植物-土壤反馈的重要组成部分。重点综述植物-土壤微生物反馈在植物群落演替过程中的作用机制,简要指出目前研究中存在的不足,并对未来研究中值得重点关注的科学问题进行了探讨与展望。 相似文献
995.
Rebecca Windsor Samuel Stewart Jessica Schmidt Mario Mosqueda Ignazio Piras Stefan M. Keller Briana Steinmetz Dori L. Borjesson Matthew Huentelman Chand Khanna 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2022,36(4):1382
BackgroundNecrotizing meningoencephalitis (NME) in the pug dogs is a fatal neuroinflammatory disease associated with rapid progression and poor response to conventional immunosuppressive therapy. Diagnosis is typically made after severe neurological abnormalities have manifested.Hypothesis/ObjectivePug dogs at genetic risk for NME might manifest neurological abnormalities before developing pathognomonic clinical signs of NME.AnimalsThirty‐six pug dogs less than 4 years of age asymptomatic for NME.MethodsProspective observational cohort study with germline genome‐wide genotyping. Neurological examinations were performed 4 weeks apart to document reproducible findings of central nervous system disease. Magnetic resonance imaging, cerebrospinal fluid analysis, and testing for infectious diseases were performed in all pugs with reproducible abnormalities detected on neurological examination.ResultsThe overall risk allele frequency in this cohort was 40%; 5 (14%) dogs were high risk, 19 (53%) dogs were medium risk, and 12 (33%) dogs were low genetic risk for NME. Reproducible abnormalities detected on neurological examination were identified in 8/24 (33%) genetically at‐risk dogs and 0/12 (0%) low risk dogs. Clinical abnormalities included multifocal spinal pain in 8/8, reduced menace response in 5/8, and lateralizing postural reaction deficits in 5/8 pugs. There was a strong association between genotype risk and the presence of this clinical phenotype (P = .03).Conclusions and Clinical ImportanceOur findings suggest the presence of a novel early clinical phenotype of NME in apparently asymptomatic genetically at‐risk pugs which might be used to plan early diagnostic and therapeutic clinical trials. 相似文献
996.
997.
Ken R. Ito Tomonori Sato Hiro Goto Katsuyoshi Sato Jun Watanabe Masaki Yokoo 《The Journal of Poultry Science》2022,59(3):247
Increasing food loss and waste (FLW) is a global problem, and efforts are being made to use waste food as potential livestock feed material. The amount of self-supplied feed is lower in Japan than in other countries, and the government recommends FLW use for animal feed. Sake (Japanese rice wine) is a traditional alcoholic beverage. During the sake manufacturing process, large amounts of squeezed solids or “lees” (sake lees) are generated. Sake lees are nutritious and functional, but are prone to spoilage. In this study, we investigated whether sake lees should be mixed with animal feed immediately or after drying. To assess the usefulness of sake lees as a poultry feed ingredient and determine the effect of sake lees on intestinal immunity, we performed a feeding trial with three treatments: a raw sake lees (RSL) diet, dried sake lees (DSL) diet, and control diet. Three-week-old broilers were fed these diets (n=8 per group) for two weeks. We then calculated feed efficiency and performed RT-qPCR to assess the effects of diet on intestinal immunity. The growth performance in the RSL diet group was equivalent to that in the control diet group. The DSL diet became difficult for broilers to eat, resulting in decreased growth performance. In the ileum of RSL-diet broilers, the mRNA expression levels of TGF-β1 and avian β-defensin (AvBD)12 were significantly increased compared to those of control diet broilers (p<0.05), and a significant correlation was observed between the two genes (p<0.05). Our results indicated that sake lees should not be dried and should be mixed immediately with feed, and this sake lees when fed to chicken activates the intestinal immunity. However, sake lees have a lower fat content than corn, and it is thus important to combine sake lees with high-energy feed. 相似文献
998.
999.
Landscape Ecology and Species Conservation 总被引:6,自引:0,他引:6
1000.
An aggregation index (AI) to quantify spatial patterns of landscapes 总被引:43,自引:0,他引:43
There is often need to measure aggregation levels of spatial patterns within a single map class in landscape ecological studies. The contagion index (CI), shape index (SI), and probability of adjacency of the same class (Qi), all have certain limits when measuring aggregation of spatial patterns. We have developed an aggregation index (AI) that is class specific and independent of landscape composition. AI assumes that a class with the highest level of aggregation (AI =1) is comprised of pixels sharing the most possible edges. A class whose pixels share no edges (completely disaggregated) has the lowest level of aggregation (AI =0). AI is similar to SI and Qi, but it calculates aggregation more precisely than the latter two. We have evaluated the performance of AI under varied levels of (1) aggregation, (2) number of patches, (3) spatial resolutions, and (4) real species distribution maps at various spatial scales. AI was able to produce reasonable results under all these circumstances. Since it is class specific, it is more precise than CI, which measures overall landscape aggregation. Thus, AI provides a quantitative basis to correlate the spatial pattern of a class with a specific process. Since AI is a ratio variable, map units do not affect the calculation. It can be compared between classes from the same or different landscapes, or even the same classes from the same landscape under different resolutions. 相似文献