TSE pathogenesis in cattle and sheep     

van Keulen LJ  Bossers A  van Zijderveld F 《Veterinary research》2008,39(4):24

Many studies have been undertaken in rodents to study the pathogenesis of transmissible spongiform encephalopathies (TSE). Only a few studies have focused on the pathogenesis of bovine spongiform encephalopathy (BSE) and scrapie in their natural hosts. In this review, we summarize the most recent insights into the pathogenesis of BSE and scrapie starting from the initial uptake of TSE agents and crossing of the gut epithelium. Following replication in the gut-associated lymphoid tissues (GALT), TSE agents spread to the enteric nervous system (ENS) of the gut. Infection is then carried through the efferent fibers of the post-ganglionic neurons of the parasympathetic and sympathetic nervous system to the pre-ganglionic neurons in the medulla oblongata of the brain and the thoracic segments of the spinal cord. The differences between the pathogenesis of BSE in cattle and scrapie in sheep are discussed as well as the possible existence of additional pathogenetic routes.  相似文献   

Foot-and-mouth disease and the use of face masks     

Donaldson AI 《The Veterinary record》2008,162(2):62

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Fluoroscopically guided neocanalization for treatment of nasolacrimal atresia in two horses     

William Berkowski  Caryn E. Plummer  Renata Ramos  Sarah Czerwinski  Dennis Brooks  Alex Gallagher 《Veterinary ophthalmology》2019,22(4):538-544

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Contrasting effects of heat shock during in vitro maturation on development of in vitro‐fertilized and parthenogenetic bovine embryos     

Luiz Sergio Almeida Camargo  Fernanda Queiros Costa  Michele Munk  Sabine Wohlres‐Viana  Raquel Varela Serapio  Bruno Campos Carvalho  Paulo Henrique Campos  Alex Cabral Vieira  Luiz Altamiro Garcia Nogueira  Joao Henrique Moreira Viana 《Reproduction in domestic animals》2019,54(10):1357-1365

This study investigated the influence of heat shock during in vitro maturation on embryo development following in vitro fertilization (IVF) or parthenogenesis (Part). Immature bovine cumulus–oocyte complexes were exposed to heat shock (41.0°C) during the first 12 hr of in vitro maturation (IVM), followed by 12 hr at 38.5°C. Control group consisted of in vitro maturation for 24 hr at 38.5°C. Oocytes were in vitro‐fertilized or activated with ionomycin and cultured in vitro for 192 hr post‐in vitro insemination or parthenogenetic activation (hpia). There was an interaction (p < .01) between temperature of IVM and method of oocyte activation (IVF or Part) for cleavage at 48 hpia. Heat shock had a negative impact (p < .01) on cleavage of IVF embryos, whereas no (p > .05) effect was found in the Part embryos. Embryo development towards blastocyst stage at 168 and 192 hpia decreased in both IVF and Part embryos derived from heat‐shocked oocytes. Heat shock increased (p < .05) the apoptotic index in Part blastocysts, but no effect (p > .05) was found in IVF counterparts. Heat shock also down‐regulated the expression of AQP3 (p < .01) and up‐regulated the expression of HSP70.1 (p < .01) in Part blastocysts, whereas it down‐regulated the expression of ATP1A1 (p < .05) in IVF blastocysts. In conclusion, the effects of heat shock during IVM on early embryo cleavage and blastocyst apoptosis are influenced by the method of oocyte activation and expression of some genes can be disturbed in embryos derived from heat‐shocked oocytes.  相似文献   

Reproductive seasonality in Saanen goats kept under tropical conditions     

Balaro  Mario Felipe A.  de Mello  Samuel Guaraná Valverde  da Silva Santos  Alex  Cavalcanti  Luiza Mattos  Almosny  Nádia Regina Pereira  Fonseca  Jeferson F.  Brandão  Felipe Z. 《Tropical animal health and production》2019,51(2):345-353

Tropical Animal Health and Production - This study aimed to verify the reproductive seasonality in Saanen goats from distinct parity orders (nulliparous, primiparous, and pluriparous) throughout an...  相似文献   

Weather-Centric Rangeland Revegetation Planning     

Stuart P. Hardegree  John T. Abatzoglou  Mark W. Brunson  Matthew J. Germino  Katherine C. Hegewisch  Corey A. Moffet  David S. Pilliod  Bruce A. Roundy  Alex R. Boehm  Gwendwr R. Meredith 《Strength and Conditioning Journal》2018,71(1):1-11

Invasive annual weeds negatively impact ecosystem services and pose a major conservation threat on semiarid rangelands throughout the western United States. Rehabilitation of these rangelands is challenging due to interannual climate and subseasonal weather variability that impacts seed germination, seedling survival and establishment, annual weed dynamics, wildfire frequency, and soil stability. Rehabilitation and restoration outcomes could be improved by adopting a weather-centric approach that uses the full spectrum of available site-specific weather information from historical observations, seasonal climate forecasts, and climate-change projections. Climate data can be used retrospectively to interpret success or failure of past seedings by describing seasonal and longer-term patterns of environmental variability subsequent to planting. A more detailed evaluation of weather impacts on site conditions may yield more flexible adaptive-management strategies for rangeland restoration and rehabilitation, as well as provide estimates of transition probabilities between desirable and undesirable vegetation states. Skillful seasonal climate forecasts could greatly improve the cost efficiency of management treatments by limiting revegetation activities to time periods where forecasts suggest higher probabilities of successful seedling establishment. Climate-change projections are key to the application of current environmental models for development of mitigation and adaptation strategies and for management practices that require a multidecadal planning horizon. Adoption of new weather technology will require collaboration between land managers and revegetation specialists and modifications to the way we currently plan and conduct rangeland rehabilitation and restoration in the Intermountain West.  相似文献   

Failure mode and bending moment of canine pancarpal arthrodesis constructs stabilized with two different implant systems     

Wininger FA  Kapatkin AS  Radin A  Shofer FS  Smith GK 《Veterinary surgery : VS》2007,36(8):724-728

Objective— To compare failure mode and bending moment of a canine pancarpal arthrodesis construct using either a 2.7 mm/3.5 mm hybrid dynamic compression plate (HDCP) or a 3.5 mm dynamic compression plate (DCP).
Study Design— Paired in vitro biomechanical testing of canine pancarpal arthrodesis constructs stabilized with either a 2.7/3.5 HDCP or 3.5 DCP.
Sample Population— Paired cadaveric canine antebrachii (n=5).
Methods— Pancarpal arthrodesis constructs were loaded to failure (point of maximum load) in 4-point bending using a materials-testing machine. Using this point of failure, bending moments were calculated from system variables for each construct and the 2 plating systems compared using a paired t-test. To examine the relationship between metacarpal diameter and screw diameter failure loads, linear regression was used and Pearson' correlation coefficient was calculated. Significance was set at P <.05.
Results— HDCP failed at higher loads than DCP for 9 of 10 constructs. The absolute difference in failure rates between the 2 plates was 0.552±0.182 N m, P =.0144 (95% confidence interval: −0.58 to 1.68). This is an 8.1% mean difference in bending strength. There was a significant linear correlation r=0.74 ( P -slope=.014) and 0.8 ( P -slope=.006) between metacarpal diameter and failure loads for the HDCP and 3.5 DCP, respectively.
Conclusion— There was a small but significant difference between bending moment at failure between 2.7/3.5 HDCP and 3.5 DCP constructs; however, the difference may not be clinically evident in all patients.
Clinical Relevance— The 2.7/3.5 HDCP has physical and mechanical properties making it a more desirable plate for pancarpal arthrodesis.  相似文献   

Update on the diagnosis of Haemophilus parasuis infection in pigs and novel genotyping methods   总被引：1，自引：0，他引：1  

Olvera A  Segalés J  Aragón V 《Veterinary journal (London, England : 1997)》2007,174(3):522-529

Haemophilus parasuis causes Gl?sser's disease as well as a number of other diseases in pigs. The diagnosis of H. parasuis-associated disease is usually established by clinical signs, pathological findings and bacterial isolation but diagnosis is complicated by the existence of non-virulent strains and the early colonisation of the upper respiratory tract of healthy piglets. Moreover, several strains can be found on a farm and even within a single animal so it is important to determine the specific strain that is causing the clinical outbreak. Recently, genotyping methods have been developed with the goal of correlating genotype with the degree of virulence of H. parasuis strains. The association between genotype and virulence in H. parasuis is challenging due to the lack of knowledge of the complete genomic sequence and virulence factors of this bacterium.  相似文献   

Ascospores as primary inoculum for epidemics of white leaf spot (Mycosphaerella capsellae) in winter oilseed rape in the UK     

Inman  Fitt  Todd  & Evans 《Plant pathology》1999,48(3):308-319

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Effects of Sewage on the Chemical Composition of Piracicaba River,Brazil     

Martinelli  Luiz A.  Krusche  Alex V.  Vicgoria  Reynaldo L.  De Camargo  Plinio B.  Bernardes  Marcelo  Ferraz  Epaminondas S.  De Moraes  Jorge M.  Ballester  Maria Victoria 《Water, air, and soil pollution》1999,110(1-2):67-79

Water samples were collected from 7 locations along major rivers of Piracicaba River basin for 22 months. The 4 upstream points represent non-polluted sites and the 3 downriver points represent polluted sites. Due to sewage input, concentrations of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), major conservative cations and anions increased significantly in the polluted sites. The major increases were observed for sodium, chloride and sulfate. Nitrate was an exception for this pattern, with similar concentrations between polluted and non-polluted sites. The probable cause was reduction of nitrate to ammonium in the polluted sites, where anoxic conditions prevail. Most of the variables had an inverse correlation with water discharge, especially in the polluted points. The sewage load was diluted by precipitation and surface waters.  相似文献