Efficacy of doramectin against experimental infections by some nematode parasites in cattle in New Zealand     

Watson TG  Hosking BC  Hooke FG 《New Zealand veterinary journal》1995,43(2):67-69

A study was undertaken to determine the efficacy of the novel avermectin, doramectin, against experimental larval and adult infections of three species of nematode parasite important to cattle production in New Zealand. Eighteen worm-free dairy bull beef calves were randomly allocated on live weight to three similar treatment groups. Each calf was given 30,000 Ostertagia ostertagi, 20,000 Cooperia spp. and 10,000 Trichostrongylus axei infective larvae as a single dose. One group was treated with doramectin 6 days after infection while the remaining groups received saline or doramectin 27 days after infection. Given as a single subcutaneous injection behind the ear, doramectin at 200 microg/kg removed 99.9-100% of adult and larval stages of O. ostertagi, Cooperia spp. and T. axei when compared to infections established in untreated controls (p<0.001). No adverse reactions were observed following treatment in the doramectin-treated animals. No injection site lesions were found by palpation following treatment or by injection site examination at necropsy.  相似文献   

Effect of circulating, maternally derived antibody on the development of a local immune response in the intestine of the neonatal pig.     

D L Watson  M A Bennell  T D Chaniago 《American journal of veterinary research》1979,40(1):61-65

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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   

Breed-related expression patterns of Ki67, γH2AX,and p21 during ageing in the canine liver     

Hardwick  Laura J. A.  Kortum  Andre J.  Constantino-Casas  Fernando  Watson  Penny J. 《Veterinary research communications》2021,45(1):21-30

Veterinary Research Communications - Cellular senescence is a molecular hallmark of ageing that is associated with multiple pathologies, and DNA damage marker γH2AX, together with cell cycle...  相似文献   

Bicarotid Trunk in the Domestic Cat          下载免费PDF全文

S. More  A. Watson  L. E. Stein 《Anatomia, histologia, embryologia》2016,45(5):350-356

The origin of the pair of common carotid arteries in the cat is inadequately described, and there are conflicting accounts in English veterinary anatomy textbooks published in the USA. We found one‐quarter of 40 adult domestic cats dissected had a bicarotid trunk (5 female, 5 male). When present, the bicarotid trunk arose from the brachiocephalic trunk approximately midway between the expected origins of the more frequently independently arising left and right common carotid arteries, and on average, it was 5.6 mm in length. Our findings make the incidence, topographical and measurement information available so that students and veterinarians can be aware of this not insignificant variation in branching of the major arteries, forming a bicarotid trunk, in the cranial mediastinum of domestic cats.  相似文献   

Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly: The EPIC Study—A Randomized Clinical Trial          下载免费PDF全文

A. Boswood  J. Häggström  S.G. Gordon  G. Wess  R.L. Stepien  M.A. Oyama  B.W. Keene  J. Bonagura  K.A. MacDonald  M. Patteson  S. Smith  P.R. Fox  K. Sanderson  R. Woolley  V. Szatmári  P. Menaut  W.M. Church  M. L. O'Sullivan  J.‐P. Jaudon  J.‐G. Kresken  J. Rush  K.A. Barrett  S.L. Rosenthal  A.B. Saunders  I. Ljungvall  M. Deinert  E. Bomassi  A.H. Estrada  M.J. Fernandez Del Palacio  N.S. Moise  J.A. Abbott  Y. Fujii  A. Spier  M.W. Luethy  R.A. Santilli  M. Uechi  A. Tidholm  P. Watson 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2016,30(6):1765-1779

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Fish assemblages in the Southern California Current: relationships with climate, 1951–2008     

J. Anthony Koslow  Ralf Goericke  William Watson 《Fisheries Oceanography》2013,22(3):207-219

We examined the dominant patterns of variability in the fish fauna of the southern California Current based on a principal component (PC) analysis of the California Cooperative Oceanic Fisheries Investigations ichthyoplankton data set, 1951–2008. Eighty‐six taxa were analyzed, including all ecologically dominant fish species, both exploited and unexploited. The first three PCs accounted for 20.5, 12.4 and 6.8% of the variance of the data, respectively (total: 39.7%). Each was dominated by taxa from particular adult or larval habitats. PC 1 predominantly represented the coherent response of 24 mesopelagic taxa from 10 families and was most highly correlated with long‐term trends in midwater oxygen levels. PC 2 was dominated by six of the seven most abundant ichthyoplankton taxa in the region, predominantly California Current endemics including key pelagic species (northern anchovy, Pacific sardine and Pacific hake), rockfishes (genus Sebastes) and two midwater taxa. It was correlated primarily with sea surface temperature and exhibited a significant declining trend. PC 3 was dominated by coastal and reef‐associated fishes with predominantly southerly affinities. It was positively correlated with sea surface temperature and sea level height, a proxy for diminished flow of the California Current. The taxa dominating PCs 2 and 3 mostly spatially co‐occur as ichthyoplankton. These results suggest that fish assemblages in the California Current are predominantly influenced by environmental forcing of their ocean habitats as adults or larvae, or both.  相似文献   

A dynamic mass-balance model for marine protected areas   总被引：2，自引：0，他引：2  

Watson  Alder  & Walters 《Fish and Fisheries》2000,1(1):94-98

A modified Ecosim model was used to investigate the impact of establishing marine protected areas (MPAs) in ecosystems defined by existing Ecopath models. The impact of MPAs of various sizes was simulated, and changes in biomass and catch over a range of years observed. The response of biomass and catch to MPA size depended on the time period examined. For some ecosystem groups, the initial response was negative, but for all groups there were increases after 10 years. The greater the biomass exchange rate across the MPA boundary, the larger the MPA required to increase biomass levels. Within the range of exchange rates simulated, the maximum increases in catch and overall biomass levels were reached when 20% of the system was protected.  相似文献   

Thirty years of change and the future of Alaskan fisheries: Shifts in fishing participation and diversification in response to environmental,regulatory and economic pressures     

Anne H. Beaudreau  Eric J. Ward  Richard E. Brenner  Andrew O. Shelton  Jordan T. Watson  Jennifer C. Womack  Sean C. Anderson  Alan C. Haynie  Kristin N. Marshall  Benjamin C. Williams 《Fish and Fisheries》2019,20(4):601-619

Heterogeneity in human responses and decision‐making can contribute to the resilience of social–ecological systems in the face of environmental, political and economic pressures. In fishery systems worldwide, the ability of harvesters to maintain a diverse portfolio of fishing strategies is important for building adaptive capacity. We used a case‐study approach to examine the complexity of factors that inhibit or promote diversification in fisheries of Alaska, one of the major fishing regions of the world. Through a combination of harvest records and literature review, we explored shifts in participation and portfolio diversity in Alaskan fisheries over three decades. The four case‐studies examined the responses of fishers, fleets and communities to multiple, intersecting pressures, including biological declines, market and price dynamics, fishery privatization and the 1989 Exxon Valdez oil spill. These cases illustrate how stressors acting at multiple scales can encourage or constrain opportunities for diversification, and that these opportunities may be spread inequitably across participants. Overall, we found evidence for reduced participation and increasing specialization in Alaskan commercial fisheries. While numerous factors explain these trends, policies like individual quota systems and the increasing cost of entry into fisheries are forcing consolidation at local to regional scales. A portfolio approach to managing fisheries that reduces barriers to diversification and includes broad representation of resource users and communities in management may help to maintain opportunity and choice for fishers.  相似文献   

A quantitative method for measuring regional economic resilience to the great recession     

Lauryn Ringwood  Philip Watson  Paul Lewin 《Growth and change》2019,50(1):381-402

Regional economic resilience can be defined as an economy’s ability to withstand and recover quickly from shocks. The ability to measure resilience is necessary to developing our understanding of what influences resilience. In this paper, we develop a new, two‐dimensional quantitative measure of resilience using observed differences between expected and actual employment in a region following a shock and distinguish the response to the shock from random variation. We demonstrate one application of this metric to US county‐level employment data to compare county responses to the 2007–2009 national recession and discuss how different regions of the United States responded to the shock of the Great Recession in terms of resilience.  相似文献