Colour-Doppler sonography of the musculophrenic vein in cows     

Braun U  Hoegger R  Haessig M 《Veterinary journal (London, England : 1997)》2009,179(3):451-454

The goal of the present study was to examine the musculophrenic vein of 29 healthy Swiss Braunvieh cows using colour-Doppler sonography to determine vessel morphology and diameter, and blood flow velocity. The hair over the reticular region was clipped, and the left musculophrenic vein was examined before and 10 min after sedation using 0.03 mg/kg xylazine. The musculophrenic vein appeared as a vessel with a diameter of 0.5–1.1 cm located in the diaphragmatic musculature. The spectral display was a broad band structure with a wave-like shape. The Doppler measurement point was 1.5–2.7 cm from the body surface. The diameter of the vein and the blood flow velocity did not differ significantly before and after sedation. Before sedation, the mean diameter (±SD) of the musculophrenic vein was 0.7 (0.2) cm, the maximum blood flow velocity 90.2 (38.6) cm/s, the mean blood flow velocity 60.4 (22.3) cm/s and the minimum blood flow velocity 41.4 (24.2) cm/s. There were significant correlations (r = 0.45–0.90) between blood flow velocity before and after sedation and between minimum, maximum and mean blood flow velocities.  相似文献   

Brachycephalic feline noses: CT and anatomical study of the relationship between head conformation and the nasolacrimal drainage system   总被引：1，自引：1，他引：0  

Claudia Schlueter DVM  Klaus D. Budras DVM PhD  Eberhard Ludewig DVM Dipl ECVDI  Elisabeth Mayrhofer DVM PhD Dipl ECVDI  Horst E. Koenig DVM PhD  Alice Walter DVM  Gerhard U. Oechtering DVM PhD Dipl ECVA 《Journal of Feline Medicine and Surgery》2009,11(11):891-900

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Impact of the spatial and temporal arrangement of pastoral use on land degradation around animal concentration points     

T. Okayasu  T. Okuro  U. Jamsran  K. Takeuchi 《Land Degradation \u0026amp; Development》2010,21(3):248-259

In mobile pastoral systems, the spatial movement of herders is tied to requirements such as water, markets and medical services, resulting in the concentration of livestock in particular areas and subsequent desertification in those areas. The spatial and temporal distributions of these requirements are subject to changes in external forces, such as political regimes and economic systems. To assess and counteract desertification requires an understanding of, and ability to predict, the spatial and temporal arrangements of such concentration points and how these arrangements cause or inhibit desertification. To this end we developed a model that explicitly simulates how animals and vegetation interact. The model has spatial settings for extensive pasture to represent the points at which animals concentrate. We found that the spatial dynamics of the interaction between animal behavior and vegetation were nonlinear and markedly affected the size of the area desertified, and that the distribution of grazing pressure was more important than total grazing pressure, which had only a limited influence on desertification. These findings indicate that application of the carrying capacity concept is not capable of preventing desertification in extensive pasture, even under equilibrium conditions. Therefore, explicit management of the spatial distribution of animals is essential to prevent desertification in extensively grazed rangelands. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

A prospective study of the effect of Neospora caninum and BVDV infections on bovine abortions in a dairy herd in Arequipa, Peru     

Ståhl K  Björkman C  Emanuelson U  Rivera H  Zelada A  Moreno-López J 《Preventive veterinary medicine》2006,75(3-4):177-188

We used a prospective seroepidemiological approach to investigate endemic abortion in a dairy herd in Arequipa, Peru, and its association with Neospora caninum and bovine viral-diarrhoea virus (BVDV) infections. Between January 2002 and March 2004, 1094 pregnancies were confirmed in 538 cows. Of these, 137 pregnancies (13%) in 121 cows ended in abortion. The serological status to N. caninum was assessed using a single serological screening, whereas BVDV status was assessed at the herd level through consecutive samplings of young stock.

Cox proportional-hazards models were used to estimate the effect of N. caninum and BVDV on the hazard of early (between day 42 and day 100 in gestation), and late (after day 100) abortions, respectively. Serological status to N. caninum was included as a dichotomous variable, and the effect of BVDV estimated at the herd level, as a time-dependent seasonal effect. Because data from repeated pregnancies were included, we considered possible lack of independence between observations and included frailty effects into the models. Our models also considered the possible confounding by parity and animal origin.

Only multiparity was associated with the hazard of early abortion (HR = 2.8 compared to nulliparous heifers). N. caninum seropositivity significantly affected the hazard of late abortion, but interacted with parity. The HRs for Neospora-positive animals were 6.4, 3.7 and 1.9, respectively, for nulliparous heifers, first-lactation cows and multiparous cows. Evidence of BVDV circulating (or not) among the young stock was not associated with abortions, but few cows in this herd were susceptible to incident infection.  相似文献   

Origin of the Roots of the Accessory Nerve in the Goitred Gazelle and Tuj Sheep     

Aslan K  Kürtü I  Bozkurt EU  Ozcan S 《Veterinary research communications》2006,30(8):839-843

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Use of social network analysis to characterize the pattern of animal movements in the initial phases of the 2001 foot and mouth disease (FMD) epidemic in the UK     

Ortiz-Pelaez A  Pfeiffer DU  Soares-Magalhães RJ  Guitian FJ 《Preventive veterinary medicine》2006,76(1-2):40-55

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Nano-TiO<Subscript>2</Subscript> based multilayer film deposition on cotton fabrics for UV-protection     

Şule S. Uğur  Merih Sarııšık  A. Hakan Aktaş 《Fibers and Polymers》2011,12(2):190-196

Nano-TiO₂ based multilayer nanocomposite films were fabricated on cationically modified woven cotton fabrics by layer-by-layer molecular self-assembly technique. Cationization process was used to obtain cationic surface charge on cotton fabrics. Attenuated total reflectance Fourier transform infrared spectroscopy analyses were used to verify the presence of cationic surface charge and multilayer films deposited on the fabrics. Scanning electron microscope micrographs of poly(sodium 4-styrene sulfonate)/TiO₂, nano polyurethane/TiO₂, and TiO₂/poly(diallyldimethylammonium chloride) multilayer films deposited on cotton fabrics were taken. With nano-TiO₂ based multilayer film deposition, the protection of cotton fabrics against UV radiation is enhanced. The UV protection durability of the self-assembled multilayer films deposited on the cotton fabrics was analyzed after 10 and 20 washing cycles at 40 °C for 30 min. Air permeability and whiteness value analysis were performed on the untreated and multilayer film deposited cotton fabrics. The effect of layer-by-layer deposition process on tensile strength properties of the warp and weft yarns was determined.  相似文献   

The influence of silvicultural treatments and site conditions on American chestnut (Castanea dentata) seedling establishment in eastern Kentucky, USA     

Chuck Rhoades  David Loftis  Jeffrey Lewis  Stacy Clark  U.S.D.A. Forest Service 《Forest Ecology and Management》2009,258(7):1211-1218

After more than 50 years of research and selective breeding, blight-resistant American chestnut (Castanea dentata) trees will soon be available for planting into the species’ pre-blight range. Increased understanding of the regeneration requirements of pure American chestnut (C. dentata [Marsh.] Borkh.) will increase the success of future efforts to establish blight-resistant chestnut. We quantified survival and initial growth of bare-root American chestnut seedlings at five locations in eastern Kentucky, USA. We used a split-plot design to compare seedlings planted within adjacent mesic and xeric sites treated with either a two-age shelterwood overstory treatment or a midstory removal treatment. The silvicultural treatments and topographic settings allowed us to evaluate chestnut seedling performance under four light and site productivity combinations. Seedling survival was 57% and seedling height averaged 94 cm following two growing seasons. Seedling survival was negatively related to sand and coarse fragment content, but was unrelated to silviculture treatment or topographic position. Chestnut seedlings grew best in shelterwood overstory treatments areas on mesic sites. Seedlings growing in shelterwood overstory treatment areas added 3- and 3.5-times more height and stem increment compared to seedlings planted after midstory removal. Seedling leaf mass and foliar nitrogen (N) content were also greatest in shelterwood plantings on mesic sites. The high-light environment created by shelterwood overstory removal resulted in better initial seedling growth, but the moderate-light of the midstory removal treatment may ultimately provide chestnut seedlings a greater advantage over competing vegetation.  相似文献   

Silvicultural treatments enhance growth rates of future crop trees in a tropical dry forest     

Z. Villegas  M. Peña-Claros  B. Mostacedo  A. Alarcón  J.C.Licona  C. Leaño  W. Pariona  U. Choque 《Forest Ecology and Management》2009

Silvicultural treatments are often needed in selectively logged tropical forest to enhance the growth rates of many commercial tree species and, consequently, for recovering a larger proportion of the initial volume harvested over the next cutting cycle. The available data in the literature suggest, however, that the effect of silvicultural treatments on tree growth is smaller in dry forests than in humid forest tree species. In this study, we analyze the effect of logging and application of additional silvicultural treatments (liana cutting and girdling of competing trees) on the growth rates of future crop trees (FCTs; i.e., trees of current and potentially commercial timber species with adequate form and apparent growth potential). The study was carried out in a tropical dry forest in Bolivia where a set of 21.25-ha plots were monitored for 4 years post-logging. Plots received one of four treatments that varied in intensity of both logging and silvicultural treatments as follows: normal (reduced-impact) logging; normal logging and low-intensity silviculture; increased logging intensity and high-intensity silviculture; and, unlogged controls. The silvicultural treatments applied to FCTs involved liberation from lianas and overtopping trees. Results showed that rates of FCT stem diameter growth increased with light availability, logging intensity, and intensity of silvicultural treatments, and decrease with liana infestation degree. Growth rate increment was larger in the light and intensive silvicultural treatment (22–27%). Long-lived pioneer species showed the strongest response to intensive silviculture (50% increase) followed by total shade-tolerant species (24%) and partial shade-tolerant species (10%). While reduced-impact logging is often not sufficient to guarantee the sustainability of timber yields, application of silvicultural treatments that substantially enhanced the growth rates of FCTs will help move the management of these forests closer to the goal of sustained yield.  相似文献   

Fast molecular detection of Pseudomonas syringae pv. aesculi in diseased horse chestnut trees     

O. Schmidt  U. Moreth  D. Dujesiefken  H. Stobbe  O. Gaiser 《Forest Pathology》2009,39(5):343-348

A molecular technique was used to detect the bacterium Pseudomonas syringae pv. aesculi in horse chestnut trees (Aesculus hippocastanum), affected by the recently recognized European ‘Pseudomonas horse chestnut bark disease’. The technique helped identify the pathogen within 6 h of sample preparation including DNA extraction, polymerase chain reaction (PCR) and electrophoresis until gel documentation. PCR primer pairs derived from the gyrase B gene sequence were used. Because of the great similarity in the gyrase B gene sequences of the numerous closely related P. syringae pathovars, the primers were not only totally specific to the pathovar aesculi, but also detected a few other pathovars. The assumption that other bacteria should not occur at least near to a necrotic lesion of a horse chestnut tree was corroborated by sequence identity of the PCR products obtained with the gyrase B gene sequence of P. syringae pv. aesculi. Koch’s postulates were fulfilled for an isolate of P. syringae pv. aesculi obtained from a diseased horse chestnut tree sampled in Hamburg in 2007.  相似文献