Changes in soil fungal:bacterial biomass ratios following reductions in the intensity of management of an upland grassland   总被引：23，自引：0，他引：23  

Richard D. Bardgett  Philip J. Hobbs  Åsa Frostegård 《Biology and Fertility of Soils》1996,22(3):261-264

In this study we examined the effect on soil fungal:bacterial biomass ratios of withholding fertiliser, lime, and sheep-grazing from reseeded upland grassland. The cessation of fertiliser applications on limed and grazed grassland resulted in a reduction in soil pH from 5.4 to 5.1. The cessation of fertiliser applications and liming on grazed grassland resulted in a fall in pH from 5.4 to 4.7, whereas withholding fertiliser and lime and the removal of grazing resulted in a further reduction to pH 4.5. Substrate-induced respiration was reduced in the unfertilised grazed (21%; P<0.01) and unfertilised ungrazed (36%; P<0.001) treatments. Bacterial substrate-induced respiration and bacterial fatty acids were unaffected by the treatments. The relative abundance of the fungal fatty acid 18:26 increased by 39 and 72% (P<0.05) in the limed grazed and unfertilised grazed treatments, respectively. Fungal substrate-induced respiration increased in the limed grazed (18%) and unfertilised grazed (65%; P<0.05) treatments. The ratio of 18:26: bacterial fatty acids was correlated with the ratio of fungal:bacterial substrate-induced respiration (r=0.69; P<0.001).  相似文献   

Estimating local extinction rates over successive time-frames     

Philip Shaw 《Biological conservation》2005,121(2):281-287

Extinction rates are commonly estimated by comparing the number of species present in successive time-frames. Although straightforward in principle, recent studies have illustrated the importance of setting a clearly defined baseline, of identifying `transient' or `vagrant' species, and of avoiding a bias towards under-recording recent extinctions. This study attempts to address these issues by identifying native, non-transient species reliably recorded in Scotland during a 100-year baseline period (1850-1949), but absent from records collected over the following 50 years. From a baseline sample of 4019 species, 1.2-1.8% were missing or considered likely to have become extinct in Scotland by 1950-1999. Insect loss rates were of a similar order of magnitude to those of better-known taxa; a finding consistent with those of recent studies, despite differences in method, region and time-frame. There was no evidence of a substantial change in the extinction rate during the baseline period. The inclusion of transient species and those likely to have been overlooked during the follow-up period had a marked effect on the loss rate, raising the estimate by a factor of 2.5. It is suggested that this approach could provide a relatively robust indicator of change in extinction rates within selected groups, but only if time-frames and the treatment of transients are defined clearly.  相似文献   

Introduction     

Philip J. Bergman 《Topics in companion animal medicine》2009,24(3):105

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Letter to the Editor     

Philip Dziuk Professor Emeritus 《Reproduction in domestic animals》1998,33(5):367-367

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Geographer,Asianist, urbanist: Celebrating the scholarship of Terry McGee     

Philip F. Kelly 《Asia Pacific viewpoint》2007,48(2):250-269

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Incidence and risk factors for bumblefoot (pododermatitis) in rehabilitated raptors     

Alfonso J. Rodriguez-Lainz  David W. Hird  Philip H. Kass  Dale L. Brooks   《Preventive veterinary medicine》1997,31(3-4):175-184

A retrospective cohort study was conducted on 821 raptors of 12 representative species, admitted to the California Raptor Center (CRC), during 1980–1990. The incidence rate for bumblefoot was 52 cases per 100 bird-years at risk. Eagles and hawks (buteos) were more likely to develop bumblefoot, and did so earlier during their captivity than other species. Also, raptors admitted with a limb fracture had the greatest risk (OR = 4.2) of developing bumblefoot than any other condition on entry. Median time from admission to development of bumblefoot was 52 days, and median duration of bumblefoot was 23 days.  相似文献   

PRELIMINARY EVALUATION OF SURVIVAL AND GROWTH OF JUVENILE RED DRUM (Sciaenops ocellata) IN FRESH AND SALT WATER     

Philip A. Crocker  Connie R. Arnold  Joan D. Holt  James A. DeBoer 《Journal of the World Aquaculture Society》1981,12(1):122-134

Heretofore few quantitative studies on the tolerance of red drum (Sciaenops ocellata Linnaeus) to freshwater (FW) or dilute sea water have been conducted. In the laboratory we subjected larval and juvenile stages of red drum to dechlorinated FW for 96 hours and found 5% survival in larvae (23-day-old, 6.2 mm SL), 70% for postlarvae (34 and 47-day-old, 16.2 mm to 19.7 mm SL) and 95% for juveniles (57-day-old, 56.9 mm SL). Survival in control salinities of 10 ppt was 90% or greater. The results indicate that tolerance to dilute media is size dependent. In a separate experiment growth of juvenile red drum (52 mm SL) over a 30-day period was compared in two raceways with flow-through supplies of dechlorinated FW, and SW of ambient (35±2 ppt) salinity. SW fish grew significantly larger (P < .01) than those acclimated to FW. Within both treatments a large size differential developed with time. Food conversion efficiency was improved and appetite drive was enhanced in the SW treatment. Percent survival after 30 days was comparably high (93%) in both treatments. Fast growth and high survival of juvenile (>20 mm SL) red drum promote the feasibility of this valuable sport and commercial species in both FW and SW aquaculture. Its potential as a control fish in FW fishery management deserves further investigation.  相似文献   

Minutes of the 71st Annual General Meeting of the Australian Veterinary Association     

Philip E Greenwood 《Australian veterinary journal》1994,71(7):225-227

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QUANTITATIVE HEPATIC SCINTIGRAPHY IN THE DOG     

Philip D.  Koblik  DVM  William J.  Hornof  DVM  MS  Eugene M.  Breznock  DVM  PhD 《Veterinary radiology & ultrasound》1983,24(5):226-231

Quantitative hepatic scintigraphy is a noninvasive test for measurement of relative arterial and portal blood flow to the liver. This technique has been used to evaluate human patients with known or suspected liver tumors or diffuse hepatocellular disease. A computer program to assess the hepatic perfusion index (HPI) in the normal dog is described. Factors affecting study quality and accuracy include injection technique, cardiac function, patient position, respiration, gross patient motion, and user intervention during data processing. HPI for a group of 12 normal dogs was 0.9±0.4 (X±SD). Quantitative scintigraphy could be used to evaluate dogs with primary or secondary liver tumors, portacaval shunts, or chronic liver disease  相似文献   

Antibodies to spotted fever-group rickettsiae in dogs and prevalence of infected ticks in southern Connecticut   总被引：2，自引：0，他引：2  

L A Magnarelli  J F Anderson  R N Philip  W Burgdorfer 《American journal of veterinary research》1982,43(4):656-659

Blood samples and ticks were obtained from dogs to assess canine exposure to spotted fever-group (SFG) rickettsiae during 1978-1980 in southern Connecticut. Of the 1,576 dog sera screened by microimmunofluorescence. 174 (11.0%) contained specific antibodies at titers greater than or equal to 1:64 against Rickettsia montana (n = 34), R rickettsii (n = 31), R rhipicephali (n = 19), or the unclassified 369-C rickettsia (n = 90). End points greater than or equal to 1:8,192 to R rickettsii and to R rhipicephali were recorded for 6 and 3 sera, respectively. Seropositivity rates from southwestern and southeastern Connecticut were similar (about 11%), with positive sera obtained from each region in nearly all months of the investigation. Rates were between 10% for dogs 2 to 7 years old and 14% for those greater than or equal to 8 years. Eight of 629 Dermacentor variabilis, 1 of 18 Ixodes dammini, and 2 of 3 Amblyomma americanum were positive by direct immunofluorescence for SFG rickettsiae. Thirteen D variabilis contained unidentified, long, bacillus-like organisms that differed from the short, ovoid (coccal) forms typical fo the spotted-fever agent, R rickettsii. With the exposure to infected ticks and production of type-specific antibodies against at least 4 SFG antigens, dogs may serve as suitable enzootic or epizootic indicators of rickettsial activity.  相似文献