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排序方式: 共有311条查询结果,搜索用时 46 毫秒
41.
Gary W. Ellison DVM MS Diplomate ACVS J. Brad Case DVM MS Diplomate ACVS‐SA Penny J. Regier DVM MS Diplomate ACVS‐SA 《Veterinary surgery : VS》2019,48(7):1171-1180
Intestinal wounds require precise closure after intestinal biopsy, enterotomy, or enterectomy in small animals. Preexisting factors such as intra‐abdominal sepsis and hypoalbuminemia as well as poor surgical technique increase the risk of intestinal dehiscence, with considerable negative impact on patient morbidity and mortality. Live dog studies have demonstrated the dangers of mucosal eversion especially in the septic abdomen. Approximating patterns preserve luminal diameter, heal optimally, and have equal bursting strength compared with inverting patterns after 24 hours. Simple interrupted and simple continuous suture patterns and disposable skin staples are established alternatives for manual wound closure. Knotless quilled suture currently used in laparoscopic gastropexy techniques shows bursting strength equal to monofilament sutures in dog cadaveric intestine. Dehiscence rates with hand sewn vs titanium automated stapling anastomosis are similar in uncomplicated cases; however, auto stapling devices may be the preferred method of anastomosis when preexisting abdominal sepsis is present and when patient size allows it. Regardless of the technique, current standard of care involves leak testing and omental wrapping, followed by early postoperative feeding. The past decade has ushered in an exciting new era of laparoscopic assisted techniques that have the potential to reduce postoperative pain and patient morbidity. An understanding of these applications will establish the future of minimally invasive small animal intestinal surgery for veterinary specialists. In summary, surgeons have a variety of methods at their disposal for optimal clinical outcome in small animal intestinal surgery. 相似文献
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43.
Brad C. Timm Kevin McGarigal Samuel A. Cushman Joseph L. Ganey 《Landscape Ecology》2016,31(6):1209-1225
Context
Organisms commonly respond to their environment across a range of scales, however many habitat selection studies still conduct selection analyses using a single-scale framework. The adoption of multi-scale modeling frameworks in habitat selection studies can improve the effectiveness of these studies and provide greater insights into scale-dependent relationships between species and specific habitat components.Objectives
Our study assessed multi-scale nest/roost habitat selection of the federally “Threatened” Mexican spotted owl (Strix occidentalis lucida) in northern Arizona, USA in an effort to provide improved conservation and management strategies for this subspecies.Methods
We conducted multi-scale habitat modeling to assess habitat selection by Mexican spotted owls using survey data collected by the USFS. Each selected covariate was included in multi-scale models at their “characteristic scale” and we used an all-subsets approach and model selection framework to assess habitat selection.Results
The “characteristic scale” identified for each covariate varied considerably among covariates and results from multi-scale models indicated that percent canopy cover and slope were the most important covariates with respect to habitat selection by Mexican spotted owls. Multi-scale models consistently outperformed their analogous single-scale counterparts with respect to the proportion of deviance explained and model predictive performance.Conclusions
Efficacy of future habitat selection studies will benefit by taking a multi-scale approach. In addition to potentially providing increased explanatory power and predictive capacity, multi-scale habitat models enhance our understanding of the scales at which species respond to their environment, which is critical knowledge required to implement effective conservation and management strategies.44.
Reproductive resilience: a paradigm shift in understanding spawner‐recruit systems in exploited marine fish
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Susan Lowerre‐Barbieri Greg DeCelles Pierre Pepin Ignacio A Catalán Barbara Muhling Brad Erisman Steven X Cadrin Josep Alós Andres Ospina‐Alvarez Megan M Stachura Michael D Tringali Sarah Walters Burnsed Claire B Paris 《Fish and Fisheries》2017,18(2):285-312
A close relationship between adult abundance and stock productivity may not exist for many marine fish stocks, resulting in concern that the management goal of maximum sustainable yield is either inefficient or risky. Although reproductive success is tightly coupled with adult abundance and fecundity in many terrestrial animals, in exploited marine fish where and when fish spawn and consequent dispersal dynamics may have a greater impact. Here, we propose an eco‐evolutionary perspective, reproductive resilience, to understand connectivity and productivity in marine fish. Reproductive resilience is the capacity of a population to maintain the reproductive success needed to result in long‐term population stability despite disturbances. A stock's reproductive resilience is driven by the underlying traits in its spawner‐recruit system, selected for over evolutionary timescales, and the ecological context within which it is operating. Spawner‐recruit systems are species specific, have both density‐dependent and fitness feedback loops and are made up of fixed, behavioural and ecologically variable traits. They operate over multiple temporal, spatial and biological scales, with trait diversity affecting reproductive resilience at both the population and individual (i.e. portfolio) scales. Models of spawner‐recruit systems fall within three categories: (i) two‐dimensional models (i.e. spawner and recruit); (ii) process‐based biophysical dispersal models which integrate physical and environmental processes into understanding recruitment; and (iii) complex spatially explicit integrated life cycle models. We review these models and their underlying assumptions about reproductive success vs. our emerging mechanistic understanding. We conclude with practical guidelines for integrating reproductive resilience into assessments of population connectivity and stock productivity. 相似文献
45.
Hwa Yeun Nam Brad Coates Kyung Seok Kim Marana Park Joon-Ho Lee 《Journal of insect science (Online)》2015,15(1)
The white-backed planthopper, Sogatella furcifera (Horváth) (Hemiptera: Delphacidae), is a major pest of rice and has long-range migratory behavior in Asia. Microsatellite markers (simple sequence repeats) have been widely used to determine the origins and genetic diversity of insect pests. We identified novel microsatellite loci for S. furcifera samples collected from Laos, Vietnam, and three localities in Bangladesh from next-generation Roche 454 pyrosequencing data. Size polymorphism at 12 microsatellite loci was verified for 40 adult individuals collected from Shinan, South Korea. The average number of alleles per locus was 7.92. The mean values of observed (Ho) and expected heterozygosities (HE) were 0.615 and 0.757, respectively. These new microsatellite markers will be a resource for future ecological genetic studies of S. furcifera samples across more broad geographic regions in Asia and may assist in estimations of genetic differentiation and gene flow among populations for implementation of more effective management strategies to control this serious rice pest. 相似文献
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47.
Brad F. Miller Tyler A. Campbell Benjamin R. Laseter W. Mark Ford Karl V. Miller 《Forest Ecology and Management》2009,258(7):1067-1072
Herbivory by white-tailed deer (Odocoileus virginianus) can affect forest regeneration. Typical measures to ensure forest regeneration have included physical barriers or direct manipulation of deer densities. However, altering silvicultural practices to provide abundant deer forage has not been tested thoroughly. We examined browse species preferences and changes in herbivory rates in 1–6 year old regeneration areas from 2001 to 2004 in the central Appalachians on the MeadWestvaco Wildlife and Ecosystem Research Forest in West Virginia. Woody vegetation reached the maximum plot coverage by the 4th growing season. However, the establishment of less abundant woody species, such as northern red oak (Quercus rubra), may be inhibited when browsed greater than or proportionally to occurrence. Herbivory rates declined precipitously as the amount of early successional habitat increased on our study site. We conclude that providing approximately 14% of an area in well-distributed, even-aged managed forests can have substantial impacts on reducing herbivory rates. However, management practices also should consider harvesting effects on hard mast production, habitat requirements of other species, and hardwood lumber marketability. 相似文献
48.
Alison M. Miller Julianne M. O’Reilly-Wapstra Brad M. Potts Clare Mcarthur 《Forest Ecology and Management》2009
Browsing by mammalian herbivores is a major problem in plantation forestry worldwide. This has traditionally been controlled through a reduction in herbivore numbers achieved by lethal means, namely shooting and poisoning. In recent years, however, there has been increasing social and political pressure to reduce reliance on such lethal controls, and consequently research into non-lethal controls is becoming increasingly important. In order for non-lethal methods to be efficiently incorporated into management, however, we must first identify those that are most effective under operational conditions. Different methods are rarely tested concurrently, and many have only been proven effective with captive animals or in small scale field trials. This study therefore sought to consolidate past research by combining non-lethal methods, which were known to significantly reduce browsing damage, into a single trial to enable their relative effectiveness to be compared under operational conditions. 相似文献
49.
PenTing Liao Melissa Sinclair Alexander Valverde Cornelia Mosley Heather Chalmers Shawn Mackenzie Brad Hanna 《Veterinary anaesthesia and analgesia》2017,44(5):1016-1026
Objectives
To compare propofol and alfaxalone, with or without midazolam, for induction of anesthesia in fentanyl-sedated dogs, and to assess recovery from total intravenous anesthesia (TIVA).Study design
Prospective, incomplete, Latin-square study.Animals
Ten dogs weighing 24.5 ± 3.1 kg (mean ± standard deviation).Methods
Dogs were randomly assigned to four treatments: treatment P-M, propofol (1 mg kg?1) and midazolam (0.3 mg kg?1); treatment P-S, propofol and saline; treatment A-M, alfaxalone (0.5 mg kg?1) and midazolam; treatment A-S, alfaxalone and saline, administered intravenously (IV) 10 minutes after fentanyl (7 μg kg?1) IV. Additional propofol or alfaxalone were administered as necessary for endotracheal intubation. TIVA was maintained for 35–55 minutes by infusions of propofol or alfaxalone. Scores were assigned for quality of sedation, induction, extubation and recovery. The drug doses required for intubation and TIVA, times from sedation to end of TIVA, end anesthesia to extubation and to standing were recorded. Analysis included a general linear mixed model with post hoc analysis (p < 0.05).Results
Significant differences were detected in the quality of induction, better in A-M than A-S and P-S, and in P-M than P-S; in total intubation dose, lower in P-M (1.5 mg kg?1) than P-S (2.1 mg kg?1), and A-M (0.62 mg kg?1) than A-S (0.98 mg kg?1); and lower TIVA rate in P-M (268 μg kg?1 minute?1) than P-S (310 μg kg?1 minute?1). TIVA rate was similar in A-M and A-S (83 and 87 μg kg?1 minute?1, respectively). Time to standing was longer after alfaxalone than propofol, but was not influenced by midazolam.Conclusions and clinical relevance
Addition of midazolam reduced the induction doses of propofol and alfaxalone and improved the quality of induction in fentanyl-sedated dogs. The dose rate of propofol for TIVA was decreased. 相似文献50.
Ana Águas Matthew J. Larcombe Hugo Matias Ernesto Deus Brad M. Potts Francisco C. Rego Joaquim S. Silva 《European Journal of Forest Research》2017,136(3):433-446
Despite the potential utility of a biogeographical approach to understanding the naturalization of exotic species, studies using this approach are scarce. Eucalyptus globulus is an economically important Australian tree species that has become naturalized in a number of countries where it was introduced. Portugal is an ideal territory to study the naturalization of E. globulus owing to: a long introduction history, the antipodal location compared to Australia and the large cultivated area. Wildling density was assessed in 116 E. globulus plantations in central Portugal through 213 transects established along plantation borders. Boosted regression trees were used to model the influence of plantation-scale variables. Results from this survey were compared with data obtained in plantations from seven Australian regions, where a similar sampling protocol had been used. In Portugal, wildlings were more abundant in plantations that were: located in moist aspects, coppiced, with older tree stems and corresponding to intermediate site growth indexes. The overall density (127 plants ha?1) was 14.9 times higher than in the Australian estate, but this ratio was reduced to 3.1 in a more comparable subset of unburnt, first rotation plantations. A generalized linear model fitted using a dataset combining the two surveys showed that country influenced wildling density, together with plantation rotation and stem age. These results provide insights into the naturalization of a widely cultivated tree species, pointing to a fundamental role of the introduction history, possibly acting along with the biogeographical characteristics of the introduced range. 相似文献