The geologically recent giant impact basins at Vesta's south pole     

Schenk P  O'Brien DP  Marchi S  Gaskell R  Preusker F  Roatsch T  Jaumann R  Buczkowski D  McCord T  McSween HY  Williams D  Yingst A  Raymond C  Russell C 《Science (New York, N.Y.)》2012,336(6082):694-697

Dawn's global mapping of Vesta reveals that its observed south polar depression is composed of two overlapping giant impact features. These large basins provide exceptional windows into impact processes at planetary scales. The youngest, Rheasilvia, is 500 kilometers wide and 19 kilometers deep and finds its nearest morphologic analog among large basins on low-gravity icy satellites. Extensive ejecta deposits occur, but impact melt volume is low, exposing an unusual spiral fracture pattern that is likely related to faulting during uplift and convergence of the basin floor. Rheasilvia obliterated half of another 400-kilometer-wide impact basin, Veneneia. Both basins are unexpectedly young, roughly 1 to 2 billion years, and their formation substantially reset Vestan geology and excavated sufficient volumes of older compositionally heterogeneous crustal material to have created the Vestoids and howardite-eucrite-diogenite meteorites.  相似文献   

Alcohol-facilitated ankylosis of the distal intertarsal and tarsometatarsal joints in horses with osteoarthritis     

Carmalt JL  Bell CD  Panizzi L  Wolker RR  Lanovaz JL  Bracamonte JL  Wilson DG 《Journal of the American Veterinary Medical Association》2012,240(2):199-204

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Viewpoints on veterinary school accreditation     

Frye C 《Journal of the American Veterinary Medical Association》2012,240(1):31-32

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Use of a medetomidine-ketamine combination for anesthesia in captive common hippopotami (Hippopotamus amphibius)     

Stalder GL  Petit T  Horowitz I  Hermes R  Saragusty J  Knauer F  Walzer C 《Journal of the American Veterinary Medical Association》2012,241(1):110-116

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Adding value for farmers through herd health plans     

Walster C 《The Veterinary record》2012,170(20):524

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Prevention of Schmallenberg virus     

Lewis C 《The Veterinary record》2012,170(9):236

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Growth and wood basic density of acacia hybrid clones at three locations in Vietnam   总被引：1，自引：0，他引：1  

Le Dinh Kha  Chris E. Harwood  Nguyen Duc Kien  Brian S. Baltunis  Nguyen Dinh Hai  Ha Huy Thinh 《New Forests》2012,43(1):13-29

Field trials testing a total of 27 clones of the interspecific hybrid Acacia mangium × A. auriculiformis and seedling controls of the parental species were established at Ba Vi and Yen Thanh in the north of Vietnam and Long Thanh in the south. At both Ba Vi and Yen Thanh there were significant (P < 0.001) differences in height and diameter at breast height (DBH) among 22 tested clones at 4 years. At Long Thanh, twelve hybrid clones did not differ significantly in DBH at age 3 years, but did (P < 0.001) at age 5 years. At the two northern sites the acacia hybrid clones had significantly greater DBH than control seedlots of the parental species. At Long Thanh, DBH of the hybrid clones and A. mangium was similar, with a genetically improved seedlot of A. mangium displaying the best DBH. Mean wood basic density at breast height of the acacia hybrid clones was 539 kg m⁻³ at Yen Thanh at age 8 years, and 473 kg m⁻³ at Long Thanh at age 5 years; density for A. mangium at Long Thanh was only slightly lower than the hybrid clones at 461 kg m⁻³. Linear regressions of Pilodyn penetration (PP) at breast height on wood basic density explained 60% of the variance in density of treatments (clones and control seedlots) at Yen Thanh and 36% at Long Thanh. There were significant differences between hybrid clones in PP at all three trial sites. Clonal DBH performance was not strongly correlated across the three trial sites; Pearson correlations of clone mean DBH between pairs of sites ranged from −0.47 to 0.20. Clonal rankings for PP were more stable, with Pearson correlations between pairs of sites ranging from r = 0.71 to 0.78.  相似文献   

A retrospective and prospective study of megaesophagus in the parma wallaby (Macropus parma) at the San Diego Zoo, California, USA     

Burgdorf-Moisuk A  Pye GW  Smith JA  Papendick R  Ivy JA  Hamlin-Andrus C 《Journal of zoo and wildlife medicine》2012,43(2):324-329

At the San Diego Zoo (California, USA), 22 cases of megaesophagus were diagnosed in the parma wallaby (Macropus parma), yielding a prevalence of 21.1%. Parma wallabies often have no clinical signs until severe and chronic dilation of the esophagus is present. Clinical signs of advanced disease include weight loss, swelling of the cervical region, regurgitation without reswallowing of ingesta, short flight distance, depression, collapse, dyspnea, and sudden death. Retrospective and prospective studies at the San Diego Zoo and a multi-institutional survey in the United States were used to try to determine the cause of megaesophagus. The retrospective study did not identify an etiology. The prospective study revealed megaesophagus and severely delayed esophageal transit time in eight of eight animals. Myasthenia gravis, lead toxicosis, toxoplasmosis, and thyroid disease were eliminated as possible causes. Of 286 living and dead parma wallabies surveyed at other institutions, three cases of esophageal diverticulum and one case of megaesophagus were reported. The cause of megaesophagus in parma wallabies was not determined.  相似文献   

Two anatomic resources of canine pelvic limb muscles based on CT and MRI     

Sunico SK  Hamel C  Styner M  Robertson ID  Kornegay JN  Bettini C  Parks J  Wilber K  Smallwood JE  Thrall DE 《Veterinary radiology & ultrasound》2012,53(3):266-272

Advances in magnetic resonance (MR) imaging and three-dimensional (3D) modeling software provide the tools necessary to create sophisticated, interactive anatomic resources that can assist in the interpretation of MR images of extremities, and learning the structure and function of limb musculature. Modeling provides advantages over dissection or consultation of print atlases because of the associated speed, flexibility, 3D nature, and elimination of superimposed arrows and labels. Our goals were to create a diagnostic atlas of pelvic limb muscles that will facilitate interpretation of MR images of patients with muscle injury and to create a 3D model of the canine pelvic limb musculature to facilitate anatomic learning. To create these resources, we used structural segmentation of MR images, a process that groups image pixels into anatomically meaningful regions. The Diagnostic Atlas is an interactive, multiplanar, web-based MR atlas of the canine pelvic limb musculature that was created by manually segmenting clinically analogous MR sequences. Higher resolution volumetric MR and computed tomography (CT) data were segmented into separately labeled volumes of data and then transformed into a multilayered 3D computer model. The 3D Model serves as a resource for students of gross anatomy, encouraging integrative learning with its highly interactive and selective display capabilities. For clinicians, the 3D Model also serves to bridge the gap between topographic and tomographic anatomy, displaying both formats alongside, or even superimposed over each other. Both projects are hosted on an open-access website, http://3dvetanatomy.ncsu.edu/  相似文献   

Disseminated mite infection with ocular involvement in a juvenile bald eagle (Haliaeetus leucocephalus)     

Bueno-Padilla I  Klauss G  Gardiner CH  Wuenschmann A 《Veterinary ophthalmology》2012,15(4):271-275

A bald eagle (Haliaeetus leucocephalus) was found unable to fly and was admitted to The Raptor Center (TRC). Major clinical signs were thin body condition and a cardiac arrhythmia. Ten days after admission to TRC, ophthalmic examination revealed multiple, distinct serpiginous lesions of chorioretinal atrophy in the ocular fundus of the right eye (OD). The bird was euthanized because of clinical deterioration and poor prognosis. Mites of an undetermined species were found histologically in the retina, episcleral tissues, lungs, and liver at the postmortem examination. Disseminated mite infection should be considered in the differential diagnosis of serpiginous chorioretinal lesions in bald eagles (H. leucocephalus).  相似文献