Initial results from long-term field studies at three sites on the effects of heavy metal-amended liquid sludges on soil microbial activity   总被引：1，自引：0，他引：1  

P. A. Gibbs    B. J. Chambers    A. M. Chaudri    S. P. McGrath  & C. H. Carlton-Smith   《Soil Use and Management》2006,22(2):180-187

In a long‐term study of the effects on soil fertility and microbial activity of heavy metals contained in sewage sludges, metal‐amended liquid sludges each with elevated Zn, Cu or Cd concentrations were applied over a 3‐year period (1995–1997) to three sites in England. The experiments were sited adjacent to experimental plots receiving metal‐rich sludge cakes enabling comparisons to be made between the effects of heavy metal additions in metal‐amended liquid sludges and sludge cakes. The liquid sludge additions were regarded as ‘worst case’ treatments in terms of likely metal availability, akin to a long‐term situation following sewage sludge additions where organic matter levels had declined and stabilised. The aim was to establish individual Zn (50–425 mg kg^?1), Cu (15–195 mg kg^?1) and Cd (0.3–4.0 mg kg^?1) metal dose–response treatments at each site, but with significantly smaller levels of organic matter addition than the corresponding sludge cake experiments. There were no differences (P > 0.05) in soil respiration rates, biomass carbon concentrations or most probable numbers of clover Rhizobium between the treatments at any of the sites at the end of the liquid sludge application programme. Soil heavy metal extractability differed between the metal‐amended liquid sludge and metal‐rich sludge cake treatments; Zn and Cd extractabilities were higher from the liquid sludge additions, whereas Cu extractability was higher from the sludge cake application. These differences in metal extractability in the treated soil samples reflected the contrasting NH₄NO₃ extractable metal contents of the metal‐amended liquid sludges and sludge cakes that were originally applied.  相似文献   

Wilhelm Caspari, 1872-1944     

Schwartz E  Chambers R 《Science (New York, N.Y.)》1947,105(2737):613

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A proteolytic transmembrane signaling pathway and resistance to beta-lactams in staphylococci     

Zhang HZ  Hackbarth CJ  Chansky KM  Chambers HF 《Science (New York, N.Y.)》2001,291(5510):1962-1965

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Integrated management practices to minimise losses and maximise the crop nitrogen value of broiler litter     

E. Sagoo  J.R. Williams  B.J. Chambers  L.O. Boyles  R. Matthews  D.R. Chadwick 《Biosystems Engineering》2007,97(4):512

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Surgical treatment of sacral fracture in a horse     

C Collatos  D Allen  J Chambers  M Henry 《Journal of the American Veterinary Medical Association》1991,198(5):877-879

An 8-year-old Arabian stallion had signs of severe tailhead pruritus and slowly progressive loss of tail tone for 3 months. Palpation per rectum and radiography of the sacrocaudal region revealed a transverse, ventrally displaced fracture of the caudal portion of the sacrum. Surgical decompression and tail amputation resulted in complete recovery of athletic and reproductive function. Evidence of cauda equina neuritis was not seen on histologic examination of nerve roots obtained at surgery.  相似文献   

Further development of equipment to measure nociceptive thresholds in large animals     

J.P. Chambers  A.E. Waterman  A. Livingston 《Veterinary anaesthesia and analgesia》1994,21(2):66-72

Existing methods of assessing pain and analgesia in large animals leave much to be desired. Equipment capable of measuring pain thresholds to a gradually increasing mechanical stimulus was developed. The device was pneumatically powered and controlled by a computer. It was used to assess pain thresholds in sheep, thoroughbred horses and human volunteers. All three species had very similar thresholds, about 5 N. The distribution of thresholds in both healthy and lame sheep was normal; the mean threshold in lame sheep was slightly but significantly lower than that in healthy sheep. Injection of saline had no effect on thresholds over six hours, but the analgesic detomidine significantly raised thresholds in both sheep and horses. The device was able to differentiate analgesia and sedation however, as acepromazine did not raise the thresholds of either species. The equipment proved robust and simple to use.  相似文献   

Hydrolytic activation and detoxication of 2,4-dichlorophenoxyacetic acid esters in mosquito fish     

Howard Chambers  L.J. Dziuk  Jo Watkins 《Pesticide biochemistry and physiology》1977,7(3):297-300

Insecticide-resistant mosquito fish (Gambusia affinis) were found to be slightly more tolerant to two thiol esters of 2,4-dichlorophenoxyacetic acid (2,4-D) than were fish of a susceptible population. DEF (S,S,S,-tributyl phosphorotrithioate), at 0.1 ppm for 24 hr, slightly decreased the toxicity of both esters to both populations. Comparison of esterase activities in gill and liver preparations showed that the resistant fish had lower levels of liver esterases than the susceptible fish, but results with gill preparation were not consistent. With the ethyl thiol ester, susceptible fish had the higher activity, but with butyl thiol ester, resistant fish had the higher activity. DEF inhibited activities in both tissues of both populations, but inhibition was appreciably greater in the liver. Results suggest that (i) hydrolysis in the liver activaties 2,4-D esters, (ii) hydrolysis in the gill is a detoxication reaction, (iii) the slight increase in tolerance in the insecticide-resistant fish is primarily the result of decreased activation, and (iv) antagonism by DEF is the result of a greater inhibition of activation than of detoxication.  相似文献   

The inhibitory effect of bovine rumen fluid on Salmonella typhimurium.     

P G Chambers  R J Lysons 《Research in veterinary science》1979,26(3):273-276

The possible fate of Salmonella typhimurium in the rumen was investigated by monitoring rumen volatile fatty acids (VFA), lactate concentrations and pH over periods which included regular feeding and 48 h starvation. Preparations were made containing 50 per cent rumen fluid from the cow or VFA solutions, and then inoculated with S typhimurium. Viable counts before and after incubation for 24 h at 37 degrees C were compared. Incubation in broths with high concentrations of VFA and low pH resulted in a marked decrease in salmonella numbers, while lower VFA concentrations had little or no inhibitory effect on growth.  相似文献   

Hydatid disease in slaughter cattle in Rhodesia     

P. G. Chambers 《Tropical animal health and production》1978,10(1):74-74

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Flavor characterization of top-blade, top-sirloin, and tenderloin steaks as affected by pH, maturity, and marbling     

Yancey EJ  Dikeman ME  Hachmeister KA  Chambers E  Milliken GA 《Journal of animal science》2005,83(11):2618-2623

Little information is available in the literature on the interrelationships and interactions among pH, aging time, marbling, and maturity on the flavor profile of some beef muscles commonly used for steaks. To investigate these effects on beef flavor, the infraspinatus (top-blade steak) from the chuck clod, the gluteus medius (top-sirloin steak) from the sirloin, and the psoas major (tenderloin steak) from the loin were obtained from A- (n = 80) and B-maturity (n = 60) carcasses with either Slight (n = 68) or Small (n = 72) marbling, and with either normal (< or = 5.7; n = 80) or high (> or = 6.0; n = 60) pH. Muscles were selected from two commercial processing plants at six different sampling times to evaluate factors that affect the flavor profile of cooked beef steaks. Muscles were vacuum-aged for 7, 14, 21, or 35 d, and a highly trained, flavor-profile sensory panel evaluated charbroiled steaks from these muscles. Numerous statistical interactions (P < 0.05) were detected for flavor attributes of the different muscles. In general, muscles from high pH (dark cutting) carcasses had less typical beef flavor identity and less brown-roasted flavor than those from carcasses with normal pH. Aging longer than 21 d generally decreased beef flavor identity. Top-blade steaks generally had less intense beef flavor identity and more intense bloody/serumy flavor than did top-sirloin and tenderloin steaks. Tenderloin and top-sirloin steaks of normal pH generally had the most brown-roasted flavor, especially when aged 21 d or less. Small degree of marbling generally resulted in a more rancid flavor compared with Slight marbling, but marbling had no other appreciable effects on the flavor profile. Aging steaks for 35 d increased (P < 0.05) the metallic flavor compared with aging for only 7 or 14 d. Top-sirloin steaks had a more intense (P < 0.05) sour flavor than did top-blade steaks, and steaks from carcasses with a high pH were more rancid (P < 0.05) than steaks from carcasses with normal pH. Vacuum-aging top-blade, top-sirloin, and tenderloin steaks to 21 or 35 d postmortem generally increased metallic and rancid flavors and increased sour flavor in top-sirloin steaks that were high in pH.  相似文献