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891.
Robert Maslak Agnieszka Sergiel Sonya P. Hill 《Journal of Veterinary Behavior: Clinical Applications and Research》2013,8(5):335-341
The behavior of 2 spectacled bears (Tremarctos ornatus) was studied at Wroclaw Zoo (Poland), where they were housed in a very small outdoor enclosure, and then in a separate study after transfer to a large naturalistic exhibit at Chester Zoo (CZ; United Kingdom). The studies combine to form an opportunistic “experiment” on the effects of transfer on zoo animals. This situation provided a unique opportunity for a closer investigation of known behavior problems and their causation. In part 1 of the study, at Wroclaw Zoo, the median amount of time devoted to stereotypical movements was 57 min/h. After the move to CZ, immediate changes in behavior were reported in 1 individual, for whom the stereotypy was eradicated. The other bear continued performing repetitive behavior of high intensity and only used a small area of the large enclosure. Signs of dental problems were subsequently observed in both bears, and so a dental examination was carried out, resulting in multiple extractions. After treatment, the amount of time that the bear with ongoing behavior problems spent stereotyping reduced significantly, and foraging increased. Our data suggest the bears' stereotypic behavior occurred not only in response to an understimulating environment in their old enclosure but also perhaps in association with medical conditions in one of the bears. Although other factors could have contributed to the observed reduction in stereotypy, it is clear that further investigation is needed into the effects of pain and physical condition on stereotypy in animals. 相似文献
892.
Roger F. Walker Robert M. Fecko Dale W. Johnson Watkins W. Miller 《Journal of Sustainable Forestry》2013,32(5):456-494
Wildfire effects on understory shrubs and herbs, regeneration of the seedling and sapling size classes, and downed and dead fuels were assessed in a mixed conifer stand located in the Lake Tahoe Basin in which California white fir (Abies concolor var. lowiana [Gord.] Lemm.) was most abundant but with Jeffrey pine (Pinus jeffreyi Grev. & Balf.) also prevalent. In burned and unburned stand portions, prefire measurements served as a basis of comparison for the postfire measurements pertinent to each study component. Fire severely suppressed the understory vegetation, which was dominated by shrubs such as bush chinquapin (Chrysolepis sempervirens [Kellogg] Hjelmqvist) and antelope bitterbrush (Purshia tridentata [Pursh] DC.), while a tepid postfire recovery of most of the preexisting species in the burned stand portion was augmented by new ones, including shrubs such as snowbrush (Ceanothus velutinus Douglas ex Hook.) and whitethorn (Ceanothus cordulatus Kellogg) ceanothus and herbs such as Holboell's rockcress (Arabis holboellii Hornem.). Tree seedling abundance was also substantially reduced in the burned portion, but the postfire population was dominated by Jeffrey pine whereas white fir had been most prevalent originally. Sapling regeneration was eliminated from the burned stand portion regardless of species. Downed and dead fuel loading was severely diminished by the fire, especially regarding fine fuels, permitting subsequent sheet erosion to imperil new seedling regeneration. These results contribute to an understanding of the direction and pace of postwildfire succession on sites occupied by Sierra Nevada mixed conifer and similar forest cover types, which is critical in decisions concerning the need for, and extent of, postfire site rehabilitation measures. 相似文献
893.
Jared R. Stapp Robert J. Lilieholm Suraj Upadhaya Tora Johnson 《Journal of Sustainable Forestry》2013,32(5):445-464
A Master Plan for Nepal’s Forestry Sector (MPFS), enacted in 1989, and subsequent legislation laid the foundation for modern community-based forest management in Nepal. In 2014, the MPFS reached the end of its 25-yr lifespan, after successfully ushering in significant institutional changes that fundamentally transformed the management of Nepal’s forests, mostly through devolving management and benefits from the national level to local communities. Here, we use the 25-yr anniversary of the MPFS to explore forest cover trends in the buffer zone surrounding Chitwan National Park (CNP). Landsat imagery was used for the years 1989, 2005, and 2013 to compute a normalized difference vegetation index (NDVI) to analyze trends in forest cover for 36 buffer zone village development committees (VDCs). The analysis, covering approximately 1,267 km2, found that since the MPFS was enacted, there was first a continued decrease in forest cover, followed by a significant recovery. These data offer insight into the success of modern community-based forest management policies and supporting institutions, and provide a model for other efforts to conserve forest resources in Nepal and elsewhere. 相似文献
894.
To determine if bifenthrin residues elicit morbidity and surfacing behavior in wireworms, larvae of the dusky wireworm, Agriotes obscurus (Coleoptera: Elateridae) were placed in field soil treated with the pyrethroid insecticide bifenthrin ~1 year previous. Morbidity was immediate and lasted as long as wireworms remained in the soil, disappearing quickly after transfer to clean soil. In 2009, field soil treated 336 days previous with bifenthrin at 340 g AI/ha elicited morbidity symptoms similar to that elicited by soil freshly amended with bifenthrin at 100 g AI, and analysis of the field soil confirmed residual levels of bifenthrin exceeding 100 g AI/ha. In 2010, wireworms placed in field soil treated 343 days previous with bifenthrin at 100, 200, and 300 g AI/ha responded as in 2009, with the degree of morbidity increasing with the rate of insecticide, and with wireworms in a non-feeding state more affected than those in a feeding state at each rate. In both 2009 and 2010, moribund wireworms moved to the soil surface within 1 day of placement in the soil containing residual bifenthrin and remained there until reburied, after which they often resurfaced. To confirm that the bifenthrin residues elicited repellency, wireworms were placed in soil window bioassays containing field soil with residual bifenthrin. Wireworms behaved markedly different upon contacting soil containing the residues than when exposed to untreated soil, both in the presence and absence of an attractant, but were less likely to avoid soil containing residual bifenthrin when attracted by wheat seedlings placed inside it. 相似文献
895.
896.
Robert Mwesigwa David Mutetikka Stephen Kabugo Donald Rugira Kugonza 《Tropical animal health and production》2013,45(8):1745-1749
To study the effect of increasing levels of wheat pollard as a replacement for wheat bran on growth and carcass characteristics of growing pigs, 64 crossbred (Landrace?×?Large white Yorkshire) pigs were fed with diets in which wheat pollard was added back to wheat bran in ratios of 15, 30, 45 and 60 %. The pigs were divided into groups of four, balanced for sex, ancestry and body weight. They were then allotted to the dietary treatments in a completely randomised design with four replications. The trial lasted 4 months and data were collected on feed intake and weight gain. A digestibility trial was carried out on eight male pigs per treatment during the growth period. At the end of the growth period, two pigs per replicate in each treatment (n?=?32) were slaughtered for determination of carcass characteristics. There were significant differences in the rate of gain and efficiency of feed utilisation among treatments. Diet significantly affected weights of the liver, lungs and small intestine (P?<?0.05). The availability of nutrients was not a limiting factor for the growing pigs and that substituting wheat bran by wheat pollard at 60 % improved the pig’s average daily gain and feed efficiency. 相似文献
897.
898.
Kate Bottoms Zvonimir Poljak Robert Friendship Rob Deardon Janet Alsop Cate Dewey 《Canadian journal of veterinary research》2013,77(4):241-253
Risk-based surveillance is becoming increasingly important in the veterinary and public health fields. It serves as a means of increasing surveillance sensitivity and improving cost-effectiveness in an increasingly resource-limited environment. Our approach for developing a tool for the risk-based geographical surveillance of contagious diseases of swine incorporates information about animal density and external biosecurity practices within swine herds in southern Ontario. The objectives of this study were to group the sample of herds into discrete biosecurity groups, to develop a map of southern Ontario that can be used as a tool in the risk-based geographical surveillance of contagious swine diseases, and to identify significant predictors of biosecurity group membership. A subset of external biosecurity variables was selected for 2-step cluster analysis and latent class analysis (LCA). It was determined that 4 was the best number of groups to describe the data, using both analytical approaches. The authors named these groups: i) high biosecurity herds that were open with respect to replacement animals; ii) high biosecurity herds that were closed with respect to replacement animals; iii) moderate biosecurity herds; and iv) low biosecurity herds. The risk map was developed using information about the geographic distribution of herds in the biosecurity groups, as well as the density of swine sites and of grower-finisher pigs in the study region. Finally, multinomial logistic regression identified heat production units (HPUs), number of incoming pig shipments per month, and herd type as significant predictors of biosecurity group membership. It was concluded that the ability to identify areas of high and low risk for disease may improve the success of surveillance and eradication projects. 相似文献
899.
Monika Martiniaková Ivana Boboňová Radoslav Omelka Birgit Grosskopf Robert Stawarz Róbert Toman 《Acta veterinaria Scandinavica》2013,55(1):8
Background
The role of selenium (Se) on bone microarchitecture is still poorly understood. The present study aims to investigate the macroscopic and microscopic structures of femoral bone tissue in adult male rats after subchronic peroral administration of Se.Methods
Twenty one-month-old male Wistar rats were randomly divided into two experimental groups. In the first group (Se group) young males were exposed to 5 mg Na2SeO3/L in drinking water, for 90 days. Ten one-month-old males without Se administration served as a control group. At the end of the experiment, macroscopic and microscopic structures of the femurs were analysed using analytical scales, sliding instrument, and polarized light microscopy.Results
The body weight, femoral length and cortical bone thickness were significantly decreased in Se group rats. These rats also displayed different microstructure in the middle part of the femur, both in medial and lateral views, where vascular canals expanded into the central area of the bone while, in control rats, these canals occurred only near the endosteal surfaces. Additionally, a smaller number of primary and secondary osteons was identified in Se group rats. Histomorphometric analyses revealed significant increases for area, perimeter, maximum and minimum diameters of primary osteons’ vascular canals but significant reductions for all measured variables of Haversian canals and secondary osteons.Conclusions
Se negatively affected the macroscopic and microscopic structures of femoral bone tissue in adult male rats. The results contribute to the knowledge on damaging impact of Se on bone. 相似文献900.
Susan A. Elmore Mark Hoenerhoff Osamu Katsuta Hiroko Kokoshima Robert Maronpot Hiroaki Nagai Hiroshi Satoh Yasuhiro Tanaka Tomoaki Tochitani Seiichiro Tsuchiya Katsuhiko Yoshizawa 《Journal of toxicologic pathology》2013,26(2):231-257
The first joint Japanese Society of Toxicologic Pathology (JSTP) and National Toxicology
Program (NTP) Satellite Symposium, entitled “Pathology Potpourri,” was held on January
29th at Okura Frontier Hotel in Tsukuba, Ibaraki, Japan, in advance of the
JSTP’s 29th Annual Meeting. The goal of this Symposium was to present current
diagnostic pathology or nomenclature issues to the toxicologic pathology community. This
article presents summaries of the speakers’ presentations, including diagnostic or
nomenclature issues that were presented, select images that were used for audience voting
or discussion, and the voting results. Some lesions and topics covered during the
symposium include: treatment-related atypical hepatocellular foci of cellular alteration
in B6C3F1 mice; purulent ventriculoencephalitis in a young BALB/c mouse; a subcutaneous
malignant schwannoma in a RccHan:WIST rat; spontaneous nasal septum
hyalinosis/eosinophilic substance in B6C3F1 mice; a rare pancreatic ductal cell adenoma in
a young Lewis rat; eosinophilic crystalline pneumonia in a transgenic mouse model; hyaline
glomerulopathy in two female ddY mice; treatment-related intrahepatic erythrocytes in
B6C3F1 mice; treatment-related subendothelial hepatocytes in B6C3F1 mice; spontaneous
thyroid follicular cell vacuolar degeneration in a cynomolgus monkey; congenital hepatic
fibrosis in a 1-year-old cat; a spontaneous adenocarcinoma of the middle ear in a young
Crl:CD(SD) rat; and finally a series of cases illustrating some differences between
cholangiofibrosis and cholangiocarcinoma in Sprague Dawley and F344 rats. 相似文献