The effects of acid rain and ozone on biomass and leaf area parameters of shortleaf pine (Pinus echinata Mill.)     

Shelburne VB  Reardon JC  Paynter VA 《Tree physiology》1993,12(2):163-172

Shortleaf pine (Pinus echinata Mill.) seedlings in 24 open-top chambers were exposed to combinations of ozone (carbon-filtered (control), ambient, 1.7 x ambient, and 2.5 x ambient) and acidic precipitation (pH 5.3, 4.3 and 3.3) for 16 months (1989 harvest) or 28 months (1990 harvest). Although the effects of acid rain were generally not significant, there was a trend toward increased aboveground biomass and leaf area in seedlings subjected to the low pH treatments. Because N concentrations in the soils generally increased with decreasing pH, we concluded that the effects of acid rain on aboveground biomass and leaf area were a consequence of an increasing concentration of soil N. In the 1989 harvest, seedlings in the 2.5 x ambient ozone treatment had significantly less biomass in all aboveground plant components and significantly less total leaf area than seedlings in the 1.7 x ambient ozone treatment. In the 1990 harvest, there were no significant effects of ozone on total aboveground biomass, although there was a trend toward reduced biomass in seedlings in the 2.5 x ambient ozone treatment. Both total leaf area and leaf biomass were significantly less in seedlings exposed to 2.5 x ambient ozone for 28 months than in both control seedlings and seedlings in the 1.7 x ambient ozone treatment. The greater, but not always significant, aboveground biomass and leaf area of seedlings in the 1.7 x ambient ozone treatment compared with control seedlings may be associated with the observed increase in soil nitrate concentration as a result of increased rates of leaf senescence and litterfall.  相似文献   

Equine pituitary pars intermedia dysfunction: current understanding and recommendations from the Australian and New Zealand Equine Endocrine Group          下载免费PDF全文

CJ Secombe  SR Bailey  MA de Laat  KJ Hughes  AJ Stewart  JM Sonis  RHH Tan 《Australian veterinary journal》2018,96(7):233-242

The purpose of this article is to provide a review of the current knowledge and opinions about the epidemiology, clinical findings (including sequelae), diagnosis, treatment and monitoring of equine pituitary pars intermedia dysfunction, particularly in the Australian context. This information and the recommendations provided will assist practitioners in making informed decisions regarding the diagnosis and management of this disorder.  相似文献   

Frequency of Undetected Glove Perforation and Associated Risk Factors in Equine Surgery          下载免费PDF全文

Yvonne A. Elce  Sheila Laverty  Eduardo Almeida da Silveira  Perrine Piat  Pierre Trencart  Pavlina Ruzickova  Richard J. M. Reardon 《Veterinary surgery : VS》2016,45(8):1066-1070

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Orthodontic correction of overjet/overbite (‘parrot mouth’) in 73 foals (1999–2013)          下载免费PDF全文

J. Easley  P. M. Dixon  R. J. M. Reardon 《Equine veterinary journal》2016,48(5):565-572

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Reproductive seasonality in a swamp-locked African cichlid     

E. E. Reardon  L. J. Chapman 《Ecology of Freshwater Fish》2008,17(1):20-29

Abstract –  This study quantified the seasonal pattern of reproduction in a swamp-dwelling population of the African cichlid Pseudocrenilabrus multicolor victoriae. In the hypoxic waters of the Lwamunda Swamp, Uganda, P. multicolor was reproductively active throughout the year, even during the peak of the dry seasons. However, the degree of activity was seasonal, with rainfall providing a predictor of the percentage of ripe, mature females. There was no correlation between aquatic oxygen availability dissolved oxygen (DO) and either adjusted mean gonad mass or percentage of mature females, suggesting that DO is not limiting reproductive activity in this system. Reproductively mature females were larger during drier periods and may maximise their lifetime reproductive success by producing young throughout the year; but with a lower brooding efficiency. A comparison with Welcomme's (1969) study of a river-swamp system feeding Lake Victoria suggests that reproductive patterning is variable among populations of P. multicolor and may reflect adaptive response to chronically hypoxic conditions in the Lwamunda Swamp.  相似文献   

An unusual paracaecal abscess associated with Fusobacterium necrophorum in a horse     

CJ TREVILLIAN  BH ANDERSON  MG COLLETT 《Australian veterinary journal》1998,76(10):659-662

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History of science. The alchemical revolution     

Reardon S 《Science (New York, N.Y.)》2011,332(6032):914-915

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Acetylcholine-synthesizing T cells relay neural signals in a vagus nerve circuit     

Rosas-Ballina M  Olofsson PS  Ochani M  Valdés-Ferrer SI  Levine YA  Reardon C  Tusche MW  Pavlov VA  Andersson U  Chavan S  Mak TW  Tracey KJ 《Science (New York, N.Y.)》2011,334(6052):98-101

Neural circuits regulate cytokine production to prevent potentially damaging inflammation. A prototypical vagus nerve circuit, the inflammatory reflex, inhibits tumor necrosis factor-α production in spleen by a mechanism requiring acetylcholine signaling through the α7 nicotinic acetylcholine receptor expressed on cytokine-producing macrophages. Nerve fibers in spleen lack the enzymatic machinery necessary for acetylcholine production; therefore, how does this neural circuit terminate in cholinergic signaling? We identified an acetylcholine-producing, memory phenotype T cell population in mice that is integral to the inflammatory reflex. These acetylcholine-producing T cells are required for inhibition of cytokine production by vagus nerve stimulation. Thus, action potentials originating in the vagus nerve regulate T cells, which in turn produce the neurotransmitter, acetylcholine, required to control innate immune responses.  相似文献   

Calving rates in a tropical beef herd after treatment with a synthetic progestagen, norgestomet, or a prostaglandin analogue, cloprostenol     

JE FRISCH  CJ O'NEILL 《Australian veterinary journal》1996,73(3):98-102

Maiden heifers and lactating cows of known ovarian status and of several breeds were treated with a synthetic prostaglandin, cloprostenol, or a synthetic progestagen, norgestomet, at the start of an artificial insemination (AI) program. Animals in the cloprostenol treatment received 2 injections 10 days apart. Over the next 26 days those animals that showed oestrous behaviour were inseminated. Synchronisation rates and calving rates to insemination over the first 7 days were calculated. Those in the norgestomet treatment received an implant of norgestomet plus an injection of norgestomet and oestradiol valerate. The implant was removed 10 days later and the animals were given an injection of pregnant mare serum gonadotrophin (PMSG). They were inseminated at 48 h (maiden heifers) or 56 h (lactating cows) after implant removal. Calving rates to fixed-time insemination were recorded. After completion of the AI program the animals in both treatments were joined with bulls. Overall calving rates (AI plus bulls) were calculated. By day 7 of the program, 82% of the maiden heifers and 76% of the lactating cows in the cloprostenol treatment had been detected in oestrus. By day 21 the respective figures were 99% and 81% Norgestomet treatment had an immediate and a prolonged effect on ovarian activity in those females classified as having inactive ovaries at the start of the AI program. Calving rates of those females to fixed-time AI and overall were similar to those of the females with active ovaries in both treatments. Their calving rates to fixed-time insemination, and overall calving rates for the lactating females, were significantly higher than the corresponding values of their contemporaries treated with cloprostenol and inseminated on observed oestrus over 7 days. For those females classified as having active ovaries at the start of the AI program, calving rates to first insemination and overall were similar for both treatments. Overall calving rates of lactating cows of each breed were, with one exception, higher in the norgestomet treatment than in the cloprostenol treatment. Although norgestomet treatment was more expensive than cloprostenol treatment, the advantage in calf crop resulted in an overall monetary advantage to the norgestomet treatment.  相似文献   

Risk factors for superficial digital flexor tendinopathy in Thoroughbred racehorses in steeplechase starts in the United Kingdom (2001–2009)     

R.J.M. Reardon  L.A. Boden  D.J. Mellor  S. Love  J.R. Newton  A.J. Stirk  T.D.H. Parkin 《Veterinary journal (London, England : 1997)》2013,195(3):325-330

The objective of this study was to identify risk factors for superficial digital flexor (SDF) tendinopathy in Thoroughbred horses in steeplechase races in the United Kingdom. Potential risk factors for SDF tendinopathy were studied between 1st January 2001 and 31st December 2009 using a cohort study design with 648 injuries sustained in 102,894 starts. Potential risk factors were screened using univariable logistic regression prior to multivariable model building.In the final multivariable model, 12 statistically significant risk factors were identified. Variables that increased the odds of SDF tendinopathy included firmer going, increased horse age, and racing in the summer compared to other seasons. Variables that decreased the odds included having a higher official rating and the number of starts in the preceding days.Fewer and different risk factors were identified than in an equivalent model of SDF tendinopathy in hurdle racing, highlighting potential differences between these disciplines. Further collection of training and racecourse information would be beneficial and may help to explain further some of the associations identified in this study. The results will facilitate the development of strategies to improve overall safety of horses in UK steeplechase racing.  相似文献