Historical range of variability in eastern Cascades forests,Washington, USA     

Agee  James K. 《Landscape Ecology》2003,18(8):725-740

The historical range of variability (HRV) has been suggested as a coarse filter approach to maintain ecosystem sustainability and resiliency. The historical range of variability in forest age structure for the central eastern Cascade Range in Washington State, USA was developed from historical fire return intervals and the manner in which fire acted as both cyclic and stochastic processes. The proportions of seven forest structural stages calculated through these processes were applied to the area of each forest series within the central eastern Cascades landscape. Early successional forest stages were more common in high elevation forest than low elevation forest. The historical proportion of old growth and late successional forest varied from 38 to 63 percent of the forested landscape. These process-based estimates are consistent with those developed from forest structural information. HRV is a valuable planning tool for ecosystem conservation purposes, but must be applied to real landscapes with consideration of both temporal and spatial scale. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Characterizing historical and modern fire regimes in Michigan (USA): A landscape ecosystem approach   总被引：4，自引：0，他引：4  

Cleland  David T.  Crow  Thomas R.  Saunders  Sari C.  Dickmann  Donald I.  Maclean  Ann L.  Jordan  James K.  Watson  Richard L.  Sloan  Alyssa M.  Brosofske  Kimberley D. 《Landscape Ecology》2004,19(3):311-325

We studied the relationships of landscape ecosystems to historical and contemporary fire regimes across 4.3 million hectares in northern lower Michigan (USA). Changes in fire regimes were documented by comparing historical fire rotations in different landscape ecosystems to those occurring between 1985 and 2000. Previously published data and a synthesis of the literature were used to identify six forest-replacement fire regime categories with fire rotations ranging from very short (<100 years) to very long (>1,000 years). We derived spatially-explicit estimates of the susceptibility of landscape ecosystems to fire disturbance using Landtype Association maps as initial units of investigation. Each Landtype Association polygon was assigned to a fire regime category based on associations of ecological factors known to influence fire regimes. Spatial statistics were used to interpolate fire points recorded by the General Land Office. Historical fire rotations were determined by calculating the area burned for each category of fire regime and dividing this area by fifteen (years) to estimate area burned per annum. Modern fire rotations were estimated using data on fire location and size obtained from federal and state agencies. Landtype Associations networked into fire regime categories exhibited differences in both historical and modern fire rotations. Historical rotations varied by 23-fold across all fire rotation categories, and modern forest fire rotations by 13-fold. Modern fire rotations were an order of magnitude longer than historical rotations. The magnitude of these changes has important implications for forest health and understanding of ecological processes in most of the fire rotation categories that we identified.This revised version was published online in May 2005 with corrections to the Cover Date.  相似文献   

Traumatic elbow luxation repair in a common squirrel monkey (Saimiri Sciureus) and a bonnet macaque (Macaca radiata).     

James F X Wellehan  Maud Lafortune  Darryl J Heard 《Journal of zoo and wildlife medicine》2004,35(2):197-202

Traumatic elbow luxation was diagnosed in a common squirrel monkey (Saimiri sciureus) and a bonnet macaque (Macaca radiata). In the common squirrel monkey, the luxation was complicated by an ulnar fracture and would not stay reduced when attempts at closed reduction were made. The luxation was surgically reduced and a transarticular type I external skeletal fixator was placed. In the bonnet macaque, closed reduction was performed and the elbow was stabilized using a cast. Both monkeys regained good function of the injured elbows.  相似文献   

Reptile neoplasia: a retrospective study of case submissions to a specialty diagnostic service.     

Michael M Garner  Sonia M Hernandez-Divers  James T Raymond 《Veterinary Clinics of North America: Exotic Animal Practice》2004,7(3):653-71, vi

This retrospective study appears to be the largest publication to date regarding the prevalence of neoplasia in reptiles. As in previous publications, neoplasia is most common in snakes, followed by lizards, chelonians, and crocodilians. Several interesting trends were documented in this study, some of which appear to be previously unidentified, and some that support the findings of previous publications.  相似文献   

Diagnosis and treatment of a cerebral infarct in a chimpanzee (Pan troglodytes).     

Pilar H Fish  James W Carpenter  Susan Kraft 《Journal of zoo and wildlife medicine》2004,35(2):203-207

A 29-yr-old chimpanzee (Pan troglodytes) presented after an acute onset of right facial and forearm paresis that progressed to paralysis within 24 hr, with subsequent development of right leg paresis. Magnetic resonance imaging (MRI) of the head revealed an abnormal region of increased signal intensity in the left frontal, parietal, and temporal cerebral hemispheres, corresponding to the vascular territory of the middle cerebral artery, with resultant compression of the left lateral ventricle. The findings were consistent with a cerebral infarct (stroke). MRI is the most sensitive test for early detection of cerebral changes due to ischemia and was essential in obtaining a diagnosis in this case. The chimpanzee responded well to treatment with long-term anticoagulant aspirin and a short, tapered course of prednisone and regained full gross motor function.  相似文献   

Comparison of Seven Digital Cameras for Digitizing Radiographs     

Benjamin Brault  DVM    James Hoskinson  DVM    Laura Armbrust  DVM    George Milliken  PhD 《Veterinary radiology & ultrasound》2004,45(4):298-304

The purpose of this study was to evaluate seven digital cameras for their ability to adequately capture quality radiographic images and their relative cost effectiveness. Radiographs of line pair (LP) phantoms (ranging from 0.6 to 16.6 LP/mm) and a 20-step contrast phantom were photographed at a near distance of 30.0 cm and a far distance (determined for each camera) at which a full 14 x 17 in film filled the viewfinder. Of the seven cameras tested, the Canon EOS-D30 consistently performed the best in LP/mm resolved (7.7 at close distance, 1.4 at far distance) and in contrast latitude (all 20 steps at both close and far distances). The Canon EOS-D30, determined to be the best camera used in this study for photographing radiographic images, is also the most expensive camera that was used. Two cameras, the Nikon Coolpix 995 and the Sony DSC-F707, were very close to the Canon in performance at considerably less cost. Certain inexpensive cameras may not be acceptable choices for teleradiology.  相似文献   

Pharmacokinetics of carfentanil and naltrexone in domestic goats (Capra hircus).     

Adrian Mutlow  Ramiro Isaza  James W Carpenter  David E Koch  Robert P Hunter 《Journal of zoo and wildlife medicine》2004,35(4):489-496

Using a crossover study design, the pharmacokinetics of carfentanil and naltrexone after i.v., i.m., and s.c. administration were determined in eight domestic goats (Capra hircus). Serial blood samples were taken up to 120 hr after carfentanil administration, and the plasma drug concentrations were determined using liquid chromatography and mass spectroscopy. All goats were immobilized with 40 microg/kg carfentanil i.m., although the resulting neurologic effects varied considerably. Plasma profiles showed rapid carfentanil absorption and a simple biphasic decline for 12-48 hr. Naltrexone given at 100 mg naltrexone/mg carfentanil 30 min after carfentanil administration produced rapid reversal of immobilization after all routes of administration. Variable fluctuations in the naltrexone plasma concentrations during the first 2.5-3.5 hr were observed, followed by a more consistent biphasic decline. The time to standing was significantly shorter after i.v. compared with s.c. naltrexone, although the time difference (1 min) had little clinical relevance. No statistically significant differences between the naltrexone pharmacokinetic parameters measured for the three routes of naltrexone administration were identified, although the recoveries after i.m. administration were, subjectively, the smoothest. The carfentanil half-life did not differ significantly in the goats given naltrexone by different routes. Although it is currently recommended that the naltrexone dose be divided into s.c. and i.v. portions, this practice does not appear to offer any benefit.  相似文献   

Noise levels in veterinary operating rooms and factors that contribute to their variations          下载免费PDF全文

Josephine Dornbusch BS  James Colee MS 《Veterinary surgery : VS》2018,47(5):678-682

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A profile of morbidity and mortality rounds within resident training programs of the American College of Veterinary Surgeons          下载免费PDF全文

Philip J. Kieffer DVM  P. O. Eric Mueller DVM  PhD  DACVS 《Veterinary surgery : VS》2018,47(3):343-349

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A century later          下载免费PDF全文

J.W. James 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2018,135(1):1-2

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