COMPUTED TOMOGRAPHY OF BALL PYTHONS (Python regius) IN CURLED RECUMBENCY     

Joanna Hedley  Kevin Eatwell  Tobias Schwarz 《Veterinary radiology & ultrasound》2014,55(4):380-386

Anesthesia and tube restraint methods are often required for computed tomography (CT) of snakes due to their natural tendency to curl up. However, these restraint methods may cause animal stress. The aim of this study was to determine whether the CT appearance of the lungs differs for ball pythons in a curled position vs. tube restraint. Whole body CT was performed on ten clinically healthy ball pythons, first in curled and then in straight positions restrained in a tube. Curved multiplanar reformatted (MPR) lung images from curled position scans were compared with standard MPR lung images from straight position scans. Lung attenuation and thickness were measured at three locations for each scan. Time for positioning and scanning was 12 ± 5 min shorter for curled snakes compared to tube restraint. Lung parenchyma thickness and attenuation declined from cranial to caudal on both straight and curled position images. Mean lung parenchyma thickness was greater in curled images at locations 1 (P = 0.048) and 3 (P = 0.044). Mean lung parenchyma thickness decreased between location 1 and 2 by 86–87% (straight: curled) and between location 1 and 3 by 51‐50% (straight: curled). Mean lung attenuation at location 1 was significantly greater on curled position images than tube restraint images (P = 0.043). Findings indicated that CT evaluation of the lungs is feasible for ball pythons positioned in curled recumbency if curved MPR is available. However, lung parenchyma thickness and attenuation in some locations may vary from those acquired using tube restraint.  相似文献   

Reference intervals and age‐related changes for venous biochemical,hematological, electrolytic,and blood gas variables using a point of care analyzer in 68 puppies     

Mauria A. O'Brien DVM  DACVECC  Maureen A. McMichael DVM  DACVECC  Kevin Le Boedec DVM  MS  George Lees DVM  MS  DACVIM 《Journal of Veterinary Emergency and Critical Care》2014,24(3):291-301

  相似文献   

Social learning in fishes: a review   总被引：14，自引：0，他引：14  

Culum Brown  & Kevin N Laland 《Fish and Fisheries》2003,4(3):280-288

Animals acquire skills and knowledge from other animals, and fish are no exception. There is now strong experimental evidence that many species of fish exhibit social learning and traditional behaviours. Here, we review the literature pertaining to social learning in fish, focusing on (i) antipredator behaviour, (ii) migration and orientation, (iii) foraging, (iv) mate choice and (v) eavesdropping.  相似文献   

Accuracy of a machine-vision pellet detection system     

Kevin D. Parsonage  Royann J. Petrell   《Aquacultural Engineering》2003,29(3-4):109-123

Video cameras are employed on net pen fish farms for monitoring food pellet levels near the cage bottom. Herein, the accuracy of a new machine-vision system for the identification of a feed-wastage event and its response time are reported. Research involved novel tests and definitions, video footage recorded under different stocking and environmental conditions, and numerical filters to reduce the effects of misclassifications and patchiness of the pellet wastage record on overall system accuracy. Single-frame food pellet detection accuracy was based on the difference between computer-generated and actual frame counts of pellets greater than 30 pixels in size. A pellet wastage event was defined as a median of three or more visible pellets per frame. During tests on still video frames from different feeding events, the system missed 0.1±0.1 to 1.3±0.4 pellets frame⁻¹, and miss-classified as pellets 0±0.1 to 2.3±0.5 objects frame⁻¹ (n=264). Most missed pellet images were on top of fish images. Waste matter accounted for 65% of the misclassifications, while particles associated with poor camera maintenance accounted for approximately 24%. The average response time to a pellet wastage event was 5.1 and 11.4 s for sampling rates of 2 frames s⁻¹ and 0.5 frames s⁻¹, respectively (n=20 different pellet wastage events). The longest response time (26 s) occurred when fish were amassed against the camera and/or covering pellets. Using appropriate camera lens, camera positioning and/or ‘warning’ software can address fish-interference problems.  相似文献   

Ecology and management of invasive riverside plants,edited by Louise C. de Waal,Lois E. Child,P. Max Wade and John H. Brock. John Wiley,Chichester, 1994. ISBN 0 471 94257 X. £45.00 hb     

Kevin Murphy 《水产资源保护:海洋与淡水生态系统》1995,5(2):170-171

  相似文献   

Machine learning highlights the importance of primary and secondary production in determining habitat for marine fish and macroinvertebrates     

Kevin D. Friedland  Michelle Bachman  Andrew Davies  Romain Frelat  M. Conor McManus  Ryan Morse  Bradley A. Pickens  Szymon Smoliński  Kisei Tanaka 《水产资源保护:海洋与淡水生态系统》2021,31(6):1482-1498

1. Species distribution models for marine organisms are increasingly used for a range of applications, including spatial planning, conservation, and fisheries management. These models have been constructed using a variety of mathematical forms and drawing on both physical and biological independent variables; however, what might be called first-generation models have mainly followed the form of linear models, or smoothing splines, informed by data collected in the context of fish surveys.
2. The performance of different classes of variables were tested in a series of species occurrence models built with machine learning methods, specifically evaluating the potential contribution of lower trophic level data. Random forest models were fitted based on the classification of the absence/presence for fish and macroinvertebrates surveyed on the US Northeast Continental Shelf.
3. The potential variables included physical, primary production, secondary production, and terrain variables. For accepted model fits, six variable importance measures were computed, which collectively showed that physical and secondary production variables make the greatest contribution across all models. In contrast, terrain variables made the least contribution to these models.
4. Multivariable analyses that account for all performance measures reinforce the role of water depth and temperature in defining species presence and absence; however, chlorophyll concentration and some specific zooplankton taxa, such as Metridia lucens and Paracalanus parvus, also make important contributions with strong seasonal variations.
5. Our results suggest that lower trophic level variables, if available, are valuable in the creation of species distribution models for marine organisms.

  相似文献   

Of Fish and Men. Tales of a Scottish Fisher. By D.C. Watson. Cualann Press, Dunfermline. Pp. 160. UK£ £10.99 (pbk). ISBN 0-9535036-3-1.     

Kevin O' Grady 《Fisheries Management and Ecology》2001,8(2):187-188

  相似文献   

Lake habitat suitability for the rare European macrophyte Najas flexilis (Willd.) Rostk. & Schmidt     

Ruth Wingfield  Kevin Murphy  Martin Gaywood 《水产资源保护:海洋与淡水生态系统》2005,15(3):227-241

  相似文献   

Assessing common bottlenose dolphin (Tursiops truncatus) population structure in Mississippi Sound and coastal waters of the north central Gulf of Mexico     

Nicole L. Vollmer  Patricia E. Rosel  Keith D. Mullin  Lori H. Schwacke  Lance P. Garrison  Brian C. Balmer  Kevin Barry  Anthony Martinez  Brian M. Quigley  Carrie Sinclair  Todd R. Speakman  Jesse Wicker  Lynsey Wilcox  Eric S. Zolman 《水产资源保护:海洋与淡水生态系统》2021,31(10):2951-2966

1. Population structure of highly mobile marine organisms can be complex and difficult to study, but it is important to understand how populations partition themselves within their environment for accurate assessment of both natural and anthropogenic impacts and successful management. The 2010 Deepwater Horizon oil spill negatively impacted common bottlenose dolphins (Tursiops truncatus) within Mississippi Sound and the surrounding north central Gulf of Mexico (GOMx); however, little was known about their underlying population structure in these waters. Thus, it was unclear how many demographically independent populations were affected by the spill.
2. Common bottlenose dolphin samples were collected throughout inshore waters of Mississippi Sound and coastal waters of the north-central GOMx. Mitochondrial DNA control region sequence data and 19 nuclear microsatellite loci were analysed to determine how many populations are present and characterize their range throughout these waters.
3. Bayesian clustering and migration analyses identified two genetically distinct and demographically independent populations: one predominantly inhabiting Mississippi Sound and adjacent coastal waters, and a second population extending generally from offshore of Mobile Bay, Alabama, east along the Florida Panhandle. Neither of these populations align with the currently delineated management stocks previously used to estimate impacts from the oil spill on common bottlenose dolphins in this portion of the GOMx.
4. These results suggest that revisions may be necessary so that management stocks accurately represent the demographically independent populations present in these waters. Furthermore, better comprehension of underlying population structure will enhance impact assessments on common bottlenose dolphins and provide more appropriate baseline data to support future restoration and conservation objectives.

  相似文献   

Big impacts from small abstractions: The effects of surface water abstraction on freshwater fish assemblages     

Nixie C. Boddy  Kevin M. Fraley  Helen J. Warburton  Phillip G. Jellyman  Doug J. Booker  Dave Kelly  Angus R. McIntosh 《水产资源保护:海洋与淡水生态系统》2020,30(1):159-172

1. Abstractions and diversions are prevalent in river networks worldwide; however, specific mechanisms and measures reflecting changes in functional characteristics of aquatic assemblages in response to flow abstraction have not been well established. In particular, the influence of small takes on fish assemblages is poorly understood.
2. Field surveys and stable‐isotope analyses were used to evaluate the impact of differing levels of flow abstraction on fish assemblage structure, and native–non‐native patterns of coexistence, associated with small surface water abstractions in four streams in New Zealand. Study design accounted for longitudinal processes (spatial autocorrelation) to isolate the effects of abstractions on fish assemblages.
3. Reaches with reduced flows downstream of abstraction points had significantly lower fish abundances per metre of stream length, probably because of decreased habitat size, altered interspecific interactions and barriers to movement. The loss of larger fish in reaches with high abstraction resulted in shallower mass–abundance slopes and shorter stable isotope‐derived food‐chain lengths, likely to have been caused by fewer trophic links in the food web. The large fish absent from these reaches were flow‐sensitive introduced salmonids, resulting in higher relative abundances of small‐bodied native fish, probably as a result of predatory and competitive release.
4. Quantification of metrics designed to characterize ecosystem functioning as well as abundance and species composition indicated that small water abstractions can alter both the structure and composition of stream fish assemblages and modify the outcomes of native–non‐native species interactions. Thus, a better understanding of the effects of small abstractions could be used to improve the strategic management of fish in invaded riverscapes.

  相似文献