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Soil saturation effects on forest dynamics: scaling across a southern boreal/northern hardwood landscape 总被引：1，自引：0，他引：1
Patch modeling can be used to scale-up processes to portray landscape-level dynamics. Via direct extrapolation, a heterogeneous landscape is divided into its constituent patches; dynamics are simulated on each representative patch and are weighted and aggregated to formulate the higher level response. Further extrapolation may be attained by coarsening the resolution of or lumping environmental data (e.g., climatic, edaphic, hydrologic, topographic) used to delimit a patch.Forest patterns at the southern boreal/northern hardwood transition zone are often defined by soil heterogeneity, determined primarily by the extent and duration of soil saturation. To determine how landscape-level dynamics predicted from direct extrapolation compare when coarsening soil parameters, we simulated forest dynamics for soil series representing a range of drainage classes from east- central Maine. Responses were aggregated according to the distribution of soil associations comprising a 600 ha area based on local- (1:12,000), county- (1:120,000) and state- (1:250,000) scale soil maps. At the patch level, simulated aboveground biomass accumulated more slowly in poorer draining soils. Different soil series yielded different communities comprised of species with various tolerances for soil saturation. When aggregated, removal of waterlogging caused a 20–60% increase in biomass accumulation during the first 50 years of simulation. However, this early successional increase and the maximum level of biomass accumulation over a 200 year period varied by as much as 40% depending on the geospatial data. This marked discrepancy suggests caution when extrapolating with forest patch models by coarsening parameters and demonstrates how rules used to rescale environmental data need to be evaluated for consistency. 相似文献
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Mermer Serhan Pfab Ferdinand Tait Gabriella Isaacs Rufus Fanning Philip D. Van Timmeren Steven Loeb Gregory M. Hesler Stephen P. Sial Ashfaq A. Hunter Jamal H. Bal Harit Kaur Drummond Francis Ballman Elissa Collins Judith Xue Lan Jiang Duo Walton Vaughn M. 《Journal of pest science》2021,94(3):743-755
The spotted-wing drosophila, Drosophila suzukii Matsumura, is an invasive pest causing significant damage to soft skinned fruits. Control of D. suzukii is critical since there is no tolerance for infested fruit in the market. While most insecticides control one or more D. suzukii life-stages (e.g., egg, larvae, and adult), the impact of insecticides that are toxic to immature stages is unclear on the subsequent generation of a field population. Insecticides were applied at field recommended rates on cherries and blueberries in the laboratory to determine immature D. suzukii mortality. Spinetoram, cyantraniliprole, malathion, methomyl, spinosad, and phosmet resulted in relatively high mortality of all immature life stages. Zeta-cypermethrin, cyclaniliprole, and fenpropathrin resulted in lower mortality of egg and all larval instars. Malathion was also applied to lowbush blueberries with different fruit sizes (small, medium, and large) in the laboratory and there was no statistical difference in mortality rates depending on fruit sizes. Mortality data from the laboratory experiments were used to parameterize a refined D. suzukii population model. The model revealed that the timing and order of different insecticide classes are important to control D. suzukii population. Model runs that included early applications of more effective insecticides resulted in high immature mortality and greater reduction of D. suzukii populations compared to treatments applied later.
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Kadar E Sykes JE Kass PH Bernsteen L Gregory CR Kyles AE 《Journal of the American Veterinary Medical Association》2005,227(6):948-953
OBJECTIVE: To determine the prevalence of infections developing postoperatively, document the contribution of infection to increased risk of death, and identify risk factors associated with the development of infectious complications in cats after renal transplantation. DESIGN: Retrospective study. ANIMALS: 169 cats that received renal allograft transplants. PROCEDURES: Medical records of cats receiving renal transplants at the University of California from January 1987 through December 2003 were reviewed. RESULTS: 47 infections developed in 43 of 169 cats. Bacterial infections were most common (25/47 cats), followed by viral (13/47), fungal (6/47), and protozoal (3/47) infections. The median duration from transplant surgery to development of infection was 2.5 months. Infection was the second most common cause of death after acute rejection of the transplant, accounting for 14% of deaths overall. Cats with concurrent diabetes mellitus had a significantly increased risk of developing an infection after renal transplantation. Sex, increasing age, concurrent neoplasia, and previous treatment for transplant rejection were not associated with development of infection. CONCLUSIONS AND CLINICAL RELEVANCE: Infection was a common complication and an important cause of death or euthanasia in cats after renal transplantation. Development of diabetes mellitus after transplantation significantly increased the risk of infection. 相似文献
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Thomas Balenghien Eric Cardinale Véronique Chevalier Nohal Elissa Anna-Bella Failloux Thiery Nirina Jean Jose Nipomichene Gaelle Nicolas Vincent Michel Rakotoharinome Matthieu Roger Betty Zumbo 《Veterinary research》2013,44(1):78
Rift Valley fever virus (Phlebovirus, Bunyaviridae) is an arbovirus causing intermittent epizootics and sporadic epidemics primarily in East Africa. Infection causes severe and often fatal illness in young sheep, goats and cattle. Domestic animals and humans can be contaminated by close contact with infectious tissues or through mosquito infectious bites. Rift Valley fever virus was historically restricted to sub-Saharan countries. The probability of Rift Valley fever emerging in virgin areas is likely to be increasing. Its geographical range has extended over the past years. As a recent example, autochthonous cases of Rift Valley fever were recorded in 2007–2008 in Mayotte in the Indian Ocean. It has been proposed that a single infected animal that enters a naive country is sufficient to initiate a major outbreak before Rift Valley fever virus would ever be detected. Unless vaccines are available and widely used to limit its expansion, Rift Valley fever will continue to be a critical issue for human and animal health in the region of the Indian Ocean. 相似文献
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Kluger EK Malik R Ilkin WJ Snow D Sullivan DR Govendir M 《Journal of the American Veterinary Medical Association》2008,233(8):1270-1277
OBJECTIVE: To compare serum triglyceride concentrations obtained after food had been withheld (i.e., fasting concentrations) in dogs with epilepsy that had been treated long term (> or = 3 months) with phenobarbital or with phenobarbital and potassium bromide with concentrations in healthy control dogs. DESIGN: Cross-sectional study. ANIMALS: 57 epileptic dogs that had been treated with phenobarbital (n=28) or with phenobarbital and bromide (29) and 57 healthy, untreated control dogs matched on the basis of age, breed, sex, neuter status, and body condition score. PROCEDURES: Blood samples were collected after food had been withheld for at least 12 hours, and serum biochemical and lipid concentrations were determined. Oral fat tolerance tests were performed in 15 control dogs and 9 dogs with epilepsy treated with phenobarbital alone. RESULTS: 19 of the 57 (33%) epileptic dogs had fasting serum triglyceride concentrations greater than the upper reference limit. Nine (16%) dogs had a history of pancreatitis, and 5 of the 9 had high fasting serum triglyceride concentrations at the time of the study. A significant relationship was found between body condition score and fasting serum triglyceride concentration in all dogs, but serum triglyceride concentration was not significantly associated with phenobarbital dosage or serum phenobarbital concentration. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that dogs treated long term with phenobarbital or with phenobarbital and bromide may develop hypertriglyceridemia. Fasting serum triglyceride concentration should be periodically monitored in dogs treated with phenobarbital because hypertriglyceridemia is a risk factor for pancreatitis. 相似文献
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Jaine H. H. L. de Oliveira Mirna H. R. Seleghim Christoph Timm Achim Grube Matthias K?ck Gislene G.F. Nascimento Ana Claudia T. Martins Elissa G. O. Silva Ana Olívia de Souza Paulo R. R. Minarini Fabio C. S. Galetti Célio L. Silva Eduardo Hajdu Roberto G. S. Berlinck 《Marine drugs》2006,4(1):1-8
Cyclostellettamines A – F (1 – 6) isolated from the sponge Pachychalina sp. and cyclostellettamines G - I, K and L (7 – 11) obtained by synthesis were evaluated in bioassays of antimicrobial activity against susceptible and antibiotic-resistant Staphylococcus aureus, Pseudomonas aeruginosa and antibiotic-susceptible Escherichia coli and Candida albicans, as well as in antimycobacterial activity against Mycobacterium tuberculosis H37Rv bioassays. The results obtained indicated that cyclostellettamines display different antimicrobial activity depending on the alkyl-chain size, suggesting that, if a mechanism-of action is implied, it is dependent on the distance between the two pyridinium moieties of cyclostellettamines. 相似文献
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Sharpley JL Marolf AJ Reichle JK Bachand AM Randall EK 《Veterinary radiology & ultrasound》2012,53(5):586-590
Benign and malignant splenic masses can appear similar on B-mode imaging, making ultrasound sensitive but not specific in their diagnosis. Our goal was to characterize color and/or power Doppler characteristics of vasculature within and adjacent to a splenic mass, which would distinguish benign vs. malignant lesions. The hypothesis was that malignant splenic masses will have altered vascular patterns compared with benign masses. Color and power Doppler cineloops evaluating the vasculature within the mass and normal splenic parenchyma were obtained in sagittal and transverse planes using a standardized protocol. Categories of evaluation included presence of peritoneal effusion, a large aberrant or tortuous vessel within the mass, relative blood flow within the mass compared with normal parenchyma, and path of vessels in the adjacent parenchyma entering into the mass. All patients had histopathologic or definitive cytologic diagnosis. Thirty-one dogs were included. There were 13 malignant masses and 18 were benign. Peritoneal effusion was significantly associated with malignancy (P = 0.0007). Presence of an aberrant or tortuous vessel within the mass was nearly significant (P = 0.059). There was no significant difference in any of the color or power Doppler blood flow evaluations. Ultrasonographic findings of a splenic mass and peritoneal effusion may indicate malignancy. The presence of an aberrant vessel within a splenic mass could suggest malignancy; however more data are needed. 相似文献
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Randall E Hansen C Gilkey D Patil A Bachand A Rosecrance J Douphrate D 《Veterinary radiology & ultrasound》2012,53(4):459-464
Between 65% and 91% of human‐patient sonographers report musculoskeletal symptoms related to their work activities. Ergonomic risk factors associated with musculoskeletal symptoms and musculoskeletal disorders (MSDs) include force, repetition, and awkward postures of the upper extremities. We hypothesized that veterinary sonographers experience similar risk factor exposures as their colleagues in human‐patient sonography, and that work‐related exposures may lead to similar prevalence of musculoskeletal symptoms and disorders. The Occupational Safety and Health Administration and Society of Diagnostic Medical Sonography published MSD prevention guidelines in 2003. Similar guidance for sonographers examining animal patients does not exist. This cross‐sectional study was designed to evaluate the prevalence of musculoskeletal symptoms among veterinary sonographers and identify reported risk factors. A 59‐item survey questionnaire was administered via email to veterinary specialists likely to perform ultrasound. Musculoskeletal pain related to performing ultrasound exams was reported by 62% of the respondents. Musculoskeletal symptoms were significantly associated with female gender (odds ratio [OR], 4.55; 95% confidence interval [CI], 2.04–10.19), age (OR, 1.06; 95% CI, 1.01, 1.10), previous work‐related trauma (OR, 6.86; 95% CI, 1.71, 27.40), not consistently using a normal height chair (OR, 2.63; 95% CI, 1.19, 5.80), and 15°–45° abduction of shoulder (OR, 2.34; 95% CI, 1.11, 4.92) . It was concluded that the prevalence of musculoskeletal symptoms among veterinary sonographers was similar to that occurring in human‐patient sonographers. © 2012 Veterinary Radiology & Ultrasound. 相似文献