Costing soil erosion: a state-wide approach     

R. E. Smyth  M. D. Young 《Land Degradation \u0026amp; Development》1998,9(6):513-527

Natural resources management is a multi-faceted discipline. It requires knowledge of the type, quantity and location of our existing natural resources, and information about how these resources are being utilized and impacted upon by human and other natural processes, whether these impacts are beneficial or detrimental and, finally, whether the impacts are reversible or have a permanent effect. Decision-makers need not only the snapshot view, but also a means to assess impact over time as land use and land-use practice change. This paper examines a methodology established to examine natural resource usage and the impacts of such usage in an integrated and repeatable fashion. Its heart is in ecological economics—a discipline which, among other things, seeks to combine economic and ecological models. The methodology was trialled initially by using it to estimate the rates of sheet and rill erosion in New South Wales, using the State-wide Resource Information and Accounting System (SRIAS), and loss hazard is estimated in physical and economic terms. The system facilitates the examination of costs to society and individuals of changes in land use and land-use practice. New estimates for the parameters of the universal soil loss equation (USLE) are derived and then mapped for the state of New South Wales. The approach is at a much finer scale than has previously been attempted. When the map of hazard of soil loss is compared with earlier maps, the physical hazard is significantly higher in the north of the state. Translation of the physical data into an economic perspective adds a new dimension to the information available to decision makers. Organization of data in this manner offers a significant opportunity to improve the cost-effectiveness of resource management. The paper reveals that failure to account for economic as well as physical rates of land degradation is likely to result in inappropriate decisions. © 1998 John Wiley & Sons, Ltd.  相似文献   

Benign masses in the pericardium of two dogs   总被引：1，自引：0，他引：1  

DJ SIMPSON  GB HUNT  DB CHURCH  JA BECK 《Australian veterinary journal》1999,77(4):225-229

Two miniature Schnauzer dogs were treated for pericardial masses. In one dog the mass consisted of necrotic fat that was attached to the apex of the pericardium by a pedicle. No obvious communication with the abdomen was present. The second dog had a peritoneopericardial hernia associated with a chronic cystic haematoma. In each case the mass was presumed to have arisen following congenital displacement of the omentum into the pericardium. The pericardial mass was removed and subtotal pericardectomy performed in both dogs. Recovery was complete in each case.  相似文献   

Role of Leptin in Modulating Neuroendocrine Function: A Metabolic Link between the Brain-Pituitary and Adipose Tissue   总被引：1，自引：0，他引：1  

CR Barb  JB Barrett  RR Kraeling  GB Rampacek 《Reproduction in domestic animals》1999,34(3-4):111-125

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The effect of acute unilateral inflammation of the equine temporomandibular joint on the kinematics of mastication          下载免费PDF全文

T. T. Smyth  J. L. Carmalt  T. T. Treen  J. L. Lanovaz 《Equine veterinary journal》2016,48(4):523-527

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Postprandial serum gastrin concentrations in normal foals     

G B Smyth  D W Young  J Schumacher 《Equine veterinary journal》1989,21(4):285-287

Postprandial gastrin concentrations were assayed in serum samples from a group of six foals at one day, one week, one month and three months of age. Before sampling, each foal was prevented from feeding for 2 h and was then allowed to suck for 15 mins. Blood samples were taken at the start of the meal and at 30 min intervals for the next 3 h. Feeding increased serum gastrin concentrations at one day, one week and one month, with the greatest increases detected at one day. Mean pre-feeding gastrin concentrations were 25.2 +/- 2.3 pg/ml at one day, 22.8 +/- 3.9 pg/ml at one week, 15.2 +/- 2.3 pg/ml at one month and 15.6 +/- 7.5 pg/ml at three months. Highest mean post prandial concentrations were at 60 mins on Day one (47.4 +/- 15.2 pg/ml) and one month (25.2 +/- 4.1 pg/ml) old foals. There was no apparent post prandial increase in serum gastrin concentrations in foals at three months of age. Precise reasons for changes in postprandial serum gastrin concentrations remain unknown. Factors that could be important include maturation of G cell function, alterations in gastrin metabolism and excretion, and changes in gastrointestinal motility with increasing age.  相似文献   

Use of a modified open patch-graft technique and valvulectomy for correction of severe pulmonic stenosis in dogs: eight consecutive cases     

GB HUNT  MRB PEARSON†  CR BELLENGER†  R MALIK† 《Australian veterinary journal》1993,70(7):244-248

SUMMARY A modified open patch-graft technique was used to correct congenital pulmonic stenosis in 8 dogs. Pulmonary valve dysplasia was moderate to severe in all cases, based upon clinical and echocardiographic criteria, and 3 dogs were in right-sided congestive heart failure at the time of surgery. Seven of the 8 dogs survived the surgery. One surviving dog displayed cerebral cortical dysfunction, the remaining 6 had no detectable neurological sequelae. Right ventricular failure was alleviated in all 7 surviving dogs, but right ventricular dilatation persisted post-operatively. Pulmonary valvulectomy and open patch-grafting provides an effective means of alleviating signs of congestive heart failure caused by pulmonary valve dysplasia, even In the presence of severe infundibular hypertrophy and dynamic outflow obstruction.  相似文献   

Pharmacokinetic studies of cimetidine hydrochloride in adult horses   总被引：1，自引：0，他引：1  

G B Smyth  S Duran  W Ravis  C R Clark 《Equine veterinary journal》1990,22(1):48-50

Histamine type II (H2) antagonists inhibit gastric acid secretion and are useful in treating gastric and duodenal ulcer disease. To provide some information on the pharmacokinetics of the H2 antagonist cimetidine, adult horses were given 3.3 mg/kg cimetidine intravenously (iv) or 3.3 and 10 mg/kg orally. Plasma cimetidine concentrations after 3.3 mg/kg orally were too low to measure. Following 3.3 mg/kg iv, cimetidine displayed two-compartment characteristics with a t1/2 of 0.083 +/- 0.039 h and t1/2 of 2.23 +/- 0.64 h. The total body clearance was 0.443 +/- 0.160 litre/h/kg and the mean residence time was 2.74 +/- 1.11 h. This clearance and t1/2 are similar to that in man. The volume of distribution (Vss) and volume of the central compartment (Vc) were 1.138 +/- 0.230 and 0.276 +/- 0.102 litre/kg, respectively. After a single oral dose of 10 mg/kg as crushed tablets, peak plasma concentration of 1.81 +/- 0.82 micrograms/ml occurred at approximately 1.4 h. Oral absorption of cimetidine appeared variable and slow with an extent of absorption of 0.296 +/- 0.183 and a mean residence time for absorption of 1.99 +/- 0.79 h. This was less than in man. Based on a desired average steady state plasma concentration of 1.0 microgram/ml, 11.0 mg/kg/day iv and 48 mg/kg/day orally can be recommended in adult horses.  相似文献   

Histochemical studies on the zona reticularis of stress-susceptible pigs     

J B Smyth  E C Appleby  M Robins 《Research in veterinary science》1984,37(3):269-272

During an investigation into the role of the adrenal gland in stress susceptibility of pigs, the large lipid masses in the inner zona reticularis were seen to be particularly related to sex differences, although stress-susceptible castrates had significantly more lipid in this zone than had stress-resistant castrates. Significant histochemical differences were also found in the activity of glucose-6-phosphate dehydrogenase and succinic dehydrogenase between the sexes and between castrates of differing susceptibility to stress. The differences in histochemical activity suggest a different origin for some of the adrenocortical cells in the inner zona reticularis.  相似文献   

Iodine deficiency in cattle: compensatory changes in thyroidal selenoenzymes     

P. Zagrodzki  F. Nicol  M.A. McCoy  J.A. Smyth  D.G. Kennedy  G.J. Beckett  J.R. Arthur 《Research in veterinary science》1998,64(3):209

The trace elements selenium and iodine are both essential for normal thyroid hormone metabolism. To investigate the relationships between these functions, heifers were maintained on iodine-deficient or iodine-sufficient diets from mid pregnancy to term. In these heifers and their offspring the interrelationship between iodine and selenium was apparent with the preferential 10- to 12-fold induction of the selenoenzyme, thyroidal type I, selenium-containing iodothyronine deiodinase activity by iodine deficiency. This was accompanied by two- to four-fold increases in cytosolic glutathione peroxidase activity, probably reflecting increased oxidative activity and metabolism in the thyroid gland in response to iodine deficiency. The above selenoenzyme activities were not affected in liver, kidney, pituitary and brain by iodine deficiency. The results are consistent with a critical role for selenium in both the normal function of cattle thyroid and key enzymes to compensate for the effects of iodine deficiency.  相似文献   

Dose–Response Studies for Pituitary and Testicular Function in Male Dogs Treated with the GnRH Superagonist, Deslorelin     

A Junaidi  PE Williamson  GB Martin  MA Blackberry  JM Cummins  TE Trigg 《Reproduction in domestic animals》2009,44(5):725-734

We tested the effect of dose of GnRH superagonist on pituitary and testicular function in a study with four groups of four male dogs. The Controls received blank implants and the other three groups received implants containing 3, 6 or 12 mg deslorelin (d ‐Trp⁶‐Pro⁹‐des‐Gly¹⁰‐GnRH ethylamide). In all deslorelin‐treated groups, there was initially an acute increase in plasma concentrations of LH and testosterone, followed by declines such that both hormones became undetectable after approximately 12 days. There was a dose–response in some of these early aspects of the hormone profiles. With respect to long‐term effects of treatment, the 12‐mg dose had significantly greater effects than the smaller doses for the duration of minimum testicular volume [366 ± 77, mean ± SEM (3 mg), 472 ± 74 (6 mg), and 634 ± 59 (12 mg) days], absence of ejaculate [416 ± 88 (3 mg), 476 ± 83 (6 mg), and 644 ± 67 (12 mg) days], undetectable plasma concentrations of LH and testosterone [367 ± 64 (3 mg), 419 ± 72 (6 mg), and 607 ± 69 (12 mg) days], the delay until complete recovery of LH and testosterone secretion [394 ± 65 (3 mg), 484 ± 72 (6 mg) and 668 ± 47 (12 mg) days], and the delay until testes had regrown to normal volume [408 ± 77 (3 mg), 514 ± 74 (6 mg), 676 ± 59 (12 mg) days]. The time taken to restore full ejaculates was also longest for the 12‐mg dose: 716 ± 67 (12 mg) days vs 440 ± 66 (3 mg) and 538 ± 83 (6 mg) days after implantation. There was no correlation between delay to recovery of normal ejaculate quality and body mass. We conclude that the dose–response relationship with deslorelin implants is not expressed with respect to the degree of suppression of reproduction, but on the maximum duration of suppression and thus to delay until recovery.  相似文献