Sagebrush conversion projects: An element of contemporary environmental change in the Western United States     

Thomas R. Vale 《Biological conservation》1974,6(4):274-284

Over 40 million ha of the western United States support a vegetative cover of big sagebrush, Artemisia tridentata. The meagre grass understory beneath the woody shrubs offers scant forage for range cattle, the primary economic product of the region. In order to improve grass supplies, both government agencies and private ranchers have undertaken a continuing programme of shrub eradication and grass planting. Various problems arise from this transformation of brushlands into grasslands, including questions of accelerated erosion, herbicide residues, and declining wildlife populations. If planned to produce a heterogeneous plant cover, however, sagebrush conversion projects could improve habitat for both domestic livestock and wildlife, while also maintaining a healthy range ecosystem.  相似文献   

Serologic immunoreactivity to Neospora caninum antigens in dogs determined by indirect immunofluorescence, western blotting and dot-ELISA   总被引：2，自引：0，他引：2  

Pinheiro AM  Costa MF  Paule B  Vale V  Ribeiro M  Nascimento I  Schaer RE  Almeida MA  Meyer R  Freire SM 《Veterinary parasitology》2005,130(1-2):73-79

Neospora caninum, is a coccidian protozoan known as a major cause of bovine abortion and canine neuropathies. The aim of the present study was to develop a reliable and quick test to detect antibodies to N. caninum in dog sera. Sixty-five serum samples from dogs, including 35 positive and 30 negative for N. caninum antibodies were used for standardization of the test. In parallel, immunoreactivity of the sera to Toxoplasma gondii antigens was investigated using a passive agglutination test. A dot-ELISA test, using soluble extract of N. caninum tachyzoites on nitrocellulose ester membranes, was developed and standardized. SDS-PAGE and complementary analysis of reactivity by Western blotting were used for the characterization of the immunoreactive fractions of all tested sera. The sensitivity and specificity of the dot-ELISA were 94 and 73%, respectively, compared to IFAT at a cut-off of 1:50, and 87 and 100% compared to IFAT at a cut-off of 1:25. Among the sera that tested positively for both IFAT and dot-ELISA, only 8.6% were reactive to T. gondii. The most immunoreactive fractions in Western blots were the 14-, 33-, 42- and 55 kDa bands, with percentages of 42, 60, 42 and 37%, respectively. The 60 kDa band showed a non-specific reaction in 43% of neosporosis-negative animals by both dot-ELISA and IFAT. These results indicate that the dot-ELISA using N. caninum antigen present good sensitivity and specificity, and might be used as a screening test to detect antibodies to N. caninum in dogs.  相似文献   

Partial lateral corpectomy for ventral extradural thoracic spinal cord compression in a cat     

Böttcher P  Flegel T  Böttcher IC  Grevel V  Oechtering G 《Journal of Feline Medicine and Surgery》2008,10(3):291-295

A 7-year-old, female spayed, domestic shorthair cat was presented for ambulatory paraparesis. No trauma history was reported. Myelography and subsequent computed tomography revealed multiple ventrally located extradural spinal cord compressive lesions possibly due to intervertebral disc disease. Compression at the level of Th3-Th4 intervertebral disc space was considered responsible for the paraparesis. The lesion was approached via a right-sided lateral partial corpectomy as described for dogs. Complete spinal decompression was achieved, as documented intraoperatively by visual inspection and palpation of the spinal canal. No surgery related complications were encountered and the cat improved gradually within 8 weeks after the procedure. At 1 year follow-up only a slight proprioceptive deficit in the right hind limb could be noted. This is the first report of partial lateral corpectomy in a cat and should encourage the use of this technique even in small patients.  相似文献   

Acaricidal activity of limonene, limonene oxide and beta-amino alcohol derivatives on Rhipicephalus (Boophilus) microplus     

Ferrarini SR  Duarte MO  da Rosa RG  Rolim V  Eifler-Lima VL  von Poser G  Ribeiro VL 《Veterinary parasitology》2008,157(1-2):149-153

Limonene, limonene oxide and eight beta-amino alcohol derivatives obtained by synthesis were investigated for the effect on egg hatchability and mortality rates of newly hatched larvae of the cattle tick Rhipicephalus (Boophilus) microplus. At the doses between 10mug/ml and 2.5mug/ml all the compounds were highly lethal to the larvae and some of them showed activity at lower concentrations. The effect on the eggs hatchability was observed in all the treatments.  相似文献   

Sustained atrial tachycardia in horses and treatment by transvenous electrical cardioversion     

G. Van Steenkiste  D. De Clercq  L. Vera  A. Decloedt  G. van Loon 《Equine veterinary journal》2019,51(5):634-640

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Effectiveness of furosemide in attenuating exercise‐induced pulmonary haemorrhage in horses when administered at 4‐ and 24‐h prior to high‐speed training          下载免费PDF全文

H. K. Knych  W. D. Wilson  A. Vale  P. H. Kass  R. M. Arthur  J. H. Jones 《Equine veterinary journal》2018,50(3):350-355

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Effect of sotalol on heart rate,QT interval,and atrial fibrillation cycle length in horses with atrial fibrillation          下载免费PDF全文

Annelies Decloedt  Dominique De Clercq  Piet Deprez  Glenn Van Steenkiste  Lisse Vera  Sofie Ven  Gunther van Loon 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2018,32(2):815-821

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Root dynamics of peach trees submitted to partial rootzone drying and continuous deficit irrigation   总被引：6，自引：0，他引：6  

J.M. Abrisqueta  O. Mounzer  S. lvarez  W. Conejero  Y. García-Orellana  L.M. Tapia  J. Vera  I. Abrisqueta  M.C. Ruiz-Snchez 《Agricultural Water Management》2008,95(8):959-967

The root dynamics of young early-season peach trees (Prunus persica L. Batsch, cv. Flordastar) were studied during one growing season. The trees were submitted to three drip irrigation treatments: T1 (control) irrigated at 100% of the estimated crop evapotranspiration (ETc) requirements, T2 (continuous deficit) irrigated at 50% ETc and T3 (partial rootzone drying, PRD, treatment), alternating irrigation from one half to the other every 2–3 weeks. Root length was measured frequently using minirhizotrons and a circular-vision scanner. Overall, root length density was reduced by ≈73% in the continuous deficit irrigated treatment and by ≈42% in the T3 treatment with respect to the well irrigated treatment. A roughly similar amount of water was applied in both deficit irrigated treatments (44 and 56% of T1, for T2 and T3, respectively), but the continuous deficit irrigation applied to both sides of the root system in T2 resulted in a greater reduction in root growth than in T3. The dynamics of the root growth were similar in the three treatments. In general, root growth declined during the fruit growth period and increased after harvest, reaching its peak in mid July. By late July, root growth had declined again, and an alternating pattern of growth between the aerial and root parts of the tree was observed. Roots were mostly located in the upper 0.55 m of soil and were particularly concentrated at 0.40–0.55 m. More than 88% of these roots were very thin, with diameters of <0.5 mm. The study looks at the impact of deficit irrigation on the phenological processes related with root growth, and will help in making decisions concerning fertigation in areas with scarce water resources where deficit irrigation strategies are considered desirable.  相似文献   

Energy efficiency in irrigation distribution networks II: Applications     

Ricardo Abadia  Carmen Rocamora  Jorge Vera 《Biosystems Engineering》2012,111(4):398-411

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A New Virus of Longan (Euphoria longana Lam.) in Hong Kong     

Vera So  S.-Y. Zee 《国际虫害防治杂志》2013,59(3):283-285

Abstract

Rattus norvegicus occurs in Singapore, with several other commensal rodent species. This preliminary study examined populations and a possible control method in urban and semi-urban areas. Commensal rats are generally undesirable, and a possible role for R. norvegicus in spreading any introduced plague is a particular worry. Populations were examined by catch, mark, release (CMR) and by removal (regression) methods. Species and numbers indicated by removal were—R. norvegicus (57.4, 31.9 and 48.5/ha in different trials), R. exulans (37.2/ha) and Mus musculus (8.3/ha). There were indications that these figures were very considerable underestimates; a Lincoln Index, using recovered dead rats (after poisoning in a CMR Plot) as the second sample, estimated R. norvegicus at 985/ha (i.e. in a ca 0.6 ha plot—618 ± 694); the recovery of only three out of 32 marked rats, and the presence of many dead but uncollected rats, even though more than the number estimated by removal was picked up in the plot (58) Banana, coconut and dried fish cage baits all trapped rats. Maize cakes were not worth the extra labour. Analysis of catch by trap position suggested that R. exulans is more common upon roofs, R. norvegicus was absent from a semi-rural environment in which R. r. diardii was common. In a control programme, wax-bound maize-based anticoagulant baits were used—distributed at 91/ha, replaced, at 2—4 day intervals if accepted, to total nine rounds and 818 baits/ha at a cost of M$21.00. Acceptance of baits was high initially, and further trapping showed that reasonable control had been obtained. This method seems more appropriate to the conditions than the permanent baiting stations used in temperate areas, because of the lack of discrete points in sewers etc., the disrupting influence of frequent tropical storms, rapid deterioration of baits, and competition from other animals, particularly ants. Drawbacks include the danger to non-target animals from the baits and the temporary stench of dead rats.  相似文献