Bilateral ureteral tears in a foal     

TJ CUTLER  RJ MACKAY  CM JOHNSON  R. PAPENDICK 《Australian veterinary journal》1997,75(6):413-415

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An oxytetracycline residue depletion study to assess the physiologically based pharmokinetic (PBPK) model in farmed Atlantic salmon.          下载免费PDF全文

J R Brocklebank  R Namdari    F C Law 《The Canadian veterinary journal. La revue veterinaire canadienne》1997,38(10):645-646

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Evaluation of ear tags impregnated with cypermethrin for the control of sheep body lice (Damalinia ovis)     

PJ JAMES  P ERKERLENZ†  RJ MEADE† 《Australian veterinary journal》1990,67(4):128-131

The application of polymer matrix ear tags impregnated with 8.5% w/w cypermethrin to 6 wethers following shearing reduced lice to non-detectable levels on 4 of them at 29 weeks after tagging. At the conclusion of the study at 45 weeks the mean count of lice on tagged wethers was 3 per sheep compared to 158 on untreated wethers. In a second experiment, 6 non-infected sheep were treated at shearing with cypermethrin tags, 6 with 25 g/l cypermethrin backline formulation, 6 with tags plus backline and 6 were left untreated. Each group was exposed to 6 sheep with moderate to heavy infestations of lice. Compared to controls, all treatments delayed infestation, but cypermethrin tags gave no longer protection than backline treatment. All sheep were infested by 17 weeks after commencement of the study. At 45 weeks mean counts of lice were 38, 27, 20 and 74 respectively for sheep treated with tags, backline formulation, backline plus tags and untreated. Possible reasons for the better effect observed from applying tags to infested sheep than to sheep which were not infected at application but which were subsequently exposed to infested sheep are discussed.  相似文献   

Selected chlorinated hydrocarbons in bottom material from streams tributary to San Francisco Bay     

L M Law  D F Goerlitz 《Pesticides monitoring journal》1974,8(1):33-36

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Development of a forest certification standard compatible with PEFC and FSC's management requirements. A case study from Greece     

Georgiadis  Nicholas M.; Cooper  RJ 《Forestry》2007,80(2):113-135

Greece currently has no national forest certification standard.This paper explains how a draft forest management standard forGreece was developed to be compatible with both the Forest StewardshipCouncil and the Programme for the Endorsement of Forest Certificationschemes requirements. The draft standard was tested in two contrastingforest areas to investigate its ease of operation, to indicatenecessary refinements to the standard and to reveal major areasof weakness in current forest management practices. Field testingshowed that the standard was operationally efficient and thatrelatively few changes to the standard were necessary. Majorweaknesses in current management practices were identified asbreaches of health and safety, poor training of forest workersand inadequate consultation with stakeholders.  相似文献   

中国林业及其高得率浆之发展   总被引：2，自引：0，他引：2  

刘桂南 《林产化学与工业》1994,14(4):69-74

对林业与纸业之关系及高得率浆的发展作了讨论，同时对林业发展制浆造纸工业的问题进行了分析。  相似文献   

Age-related changes in ecosystem structure and function and effects on water and carbon exchange in ponderosa pine     

Irvine J  Law BE  Kurpius MR  Anthoni PM  Moore D  Schwarz PA 《Tree physiology》2004,24(7):753-763

As forests age, their structure and productivity change, yet in some cases, annual rates of water loss remain unchanged. To identify mechanisms that might explain such observations, and to determine if widely different age classes of forests differ functionally, we examined young (Y, approximately 25 years), mature (M, approximately 90 years) and old (O, approximately 250 years) ponderosa pine (Pinus ponderosa Dougl. ex P. Laws.) stands growing in a drought-prone region of central Oregon. Although the stands differed in tree leaf area index (LAIT) (Y = 0.9, M = 2.8, O = 2.1), cumulative tree transpiration measured by sap flow did not differ substantially during the growing season (100-112 mm). Yet when water was readily available, transpiration per unit leaf area of the youngest trees was about three times that of M trees and five times that of O trees. These patterns resulted from a nearly sixfold difference in leaf specific conductance (KL) between the youngest and oldest trees. At the time of maximum transpiration in the Y stand in May-June, gross carbon uptake (gross ecosystem production, GEP) was similar for Y and O stands despite an almost twofold difference in stand leaf area index (LAIS). However, the higher rate of water use by Y trees was not sustainable in the drought-prone environment, and between spring and late summer, KL of Y trees declined fivefold compared with a nearly twofold decline for M trees and a < 30% reduction in O trees. Because the Y stand contained a significant shrub understory and more exposed soil, there was no appreciable difference in mean daily latent energy fluxes between the Y stand and the older stands as measured by the eddy-covariance technique. These patterns resulted in 60 to 85% higher seasonal GEP and 55 to 65% higher water-use efficiency at the M and O stands compared with the Y stand.  相似文献   

Carbon dioxide and water vapor exchange by young and old ponderosa pine ecosystems during a dry summer     

Law BE  Goldstein AH  Anthoni PM  Unsworth MH  Panek JA  Bauer MR  Fracheboud JM  Hultman N 《Tree physiology》2001,21(5):299-308

We investigated key factors controlling mass and energy exchange by a young (6-year-old) ponderosa pine (Pinus ponderosa Laws.) plantation on the west side of the Sierra Nevada Mountains and an old-growth ponderosa pine forest (mix of 45- and 250-year-old trees) on the east side of the Cascade Mountains, from June through September 1997. At both sites, we operated eddy covariance systems above the canopy to measure net ecosystem exchange of carbon dioxide and water vapor, and made concurrent meteorological and ecophysiological measurements. Our objective was to understand and compare the controls on ecosystem processes in these two forests. Precipitation is much higher in the young plantation than in the old-growth forest (1660 versus 550 mm year-1), although both forests experienced decreasing soil water availability and increasing vapor pressure deficits (D) as the summer of 1997 progressed. As a result, drought stress increased at both sites during this period, and changes in D strongly influenced ecosystem conductance and net carbon uptake. Ecosystem conductance for a given D was higher in the young pine plantation than in the old-growth forest, but decreased dramatically following several days of high D in late summer, possibly because of xylem cavitation. Net CO2 exchange generally decreased with conductance at both sites, although values were roughly twice as high at the young site. Simulations with the 3-PG model, which included the effect of tree age on fluxes, suggest that, during the fall through spring period, milder temperatures and ample water availability at the young site provide better conditions for photosynthesis than at the old pine site. Thus, over the long-term, the young site can carry more leaf area, and the climatic conditions between fall and spring offset the more severe limitations imposed by summer drought.  相似文献   

Hypertrophic osteopathy in an alpaca     

C. CURTIS  AJ DART  RJ RAWLINSON  DR HODGSON 《Australian veterinary journal》1997,75(1):61-62

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Physiological and biochemical consequences of electroimobilisation in conscious sheep     

TR KUCHEL  LE MATHER†  WB RUNCIMAN†  RJ CARAPETIS† 《Australian veterinary journal》1990,67(2):33-38

An electroimmobilisation device has been developed to facilitate the automated shearing of sheep, but there is little information on its effects on the body. We have studied its effects on the cardiovascular system and on intermediary metabolism in sheep. Electroimmobilisation caused statistically significant increases in mean arterial pressure, heart rate, cardiac output, renal and hepatic and hindquarter glucose and lactate flux, organ and whole body oxygen flux, hindquarter blood flow and core temperature and decreases in arterial and posterior vena cava blood pH, renal and hepatic blood flow and PaCO2. Notably, no change occurred in PaO2. The metabolic changes demonstrated the capacity of sheep to respond to the increased muscular and cardiovascular work induced by electroimmobilisation. Pulmonary function was not compromised during electroimmobilisation as judged from blood gas changes, and the acid/base changes were rapidly reversed after electroimmobilisation. The recovery to control conditions for all perturbations generally took no longer than 30 min, consistent with a rapid and physiologically adequate reversal by the animal's homeostatic mechanisms.  相似文献