Changes in total carbon and nutrients in soil profiles and accumulation in biomass after a 30-year rotation of Pinus radiata on podzolized sands: Impacts of intensive harvesting on soil resources     

Peter Hopmans  Stephen R. Elms 《Forest Ecology and Management》2009

A large proportion of plantations of radiata pine (Pinus radiata D. Don) in southern Australia have been established on podzolized coastal sands with low nutrient reserves. Inter-rotational management of the forest floor and harvesting residues has been shown to be critical to maintain the productive capacity of these soils. In 1974 a study was initiated at the end of the first rotation to evaluate the long-term sustainability of fast-growing plantations on these podzolized sands. Growth was measured at 5, 10 and 20 years and prior to clear-felling at age 30. Soil sampling at the end of the first rotation in 1974 was repeated in 2004 prior to clear-felling to determine changes in carbon and nutrients in profiles after 30 years. Forest floor and tree biomass were measured to determine sequestration of carbon and nutrients in mature radiata pine.  相似文献   

Prevalence of exon 11 internal tandem duplications in the C‐KIT proto‐oncogene in Australian canine mast cell tumours          下载免费PDF全文

VS Tamlin  AE Kessell  RJ Mccoy  EC Dobson  TS Smith  M Hebart  L Brown  D Mitrovic  AE Peaston 《Australian veterinary journal》2017,95(10):386-391

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Transphyseal vessel involvement in repair of metaphyseal retained cartilage     

EC FIRTH  A. KLARENBEEK 《Australian veterinary journal》1995,72(12):452-455

SUMMARY A foal with retained cartilage in the distal metaphysis of the right and left radii and third metacarpal bones had abnormal physeal vasculature. In areas where cartilage was retained, vessels crossed the physis, and branched at the physeal-metaphyseal junction or at the site of retained cartilage. Vessels appeared to be involved in re-initiation of endochondral ossification and in the repair reponse to the presence of retained cartilage. In areas where the physis was radiographically and histologically normal, no vessels crossed the physis. A function of transphyseal vessels may be as a reserve blood supply in areas of metaphyseal abnormality, at a stage of maturity when metaphyseal vessels are not well developed.  相似文献   

Pain-related cerebral potentials in response to acute painful electrical stimulation in sheep     

JP MORRIS  RM ONG  JK O'DWYER  JL BARNETT  PH HEMSWORTH  IJ CLARKE  EC JONGMAN 《Australian veterinary journal》1997,75(12):883-886

Objective To examine associations between late event-related cerebral potential amplitudes and behavioural responses to noxious electrical stimulation as an indicator of acute pain in sheep.
Design Analysis of variance for the effects of stimulus intensity on the behaviour and event-related cerebral potential variables.
Procedure Ninety-six brief constant current electrical pulse trains were presented to the front left leg of eight sheep at four intensities (2.5 to 10 mA) in a randomised order. An event-related cerebral potential and a graded flinch response were recorded for each stimulus and the 24 event-related cerebral potentials at each intensity were averaged to produce a mean waveform. Various components of this waveform were analysed and changes in these measures and the sheep's flinch response, as stimulus intensity increased, were determined.
Results Both the flinch response and some event-related cerebral potential components, that is, peak amplitudes 114 {N1}, 187 {P1}, 318 {P2} and 230 {Pm} ms after stimulus onset, were significantly affected as stimulus intensity increased.
Conclusion These corresponding behavioural and event-related cerebral potential changes indicate the usefulness of using changes in the event-related cerebral potential to measure acute pain in sheep.  相似文献   

Susceptibility of freshly-mulesed lambs to flystrike and the effectiveness of propetamphos as a wound dressing     

SA HARRINGTON  EC STEINER 《Australian veterinary journal》1993,70(5):190-191

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Atypical Brucella sp in captive Australian green tree frogs (Litoria caerulea): clinical features,pathology, culture and molecular characterization     

S Latheef  A Keyburn  I Broz  A Bagnara  C Bayley  S Frith  EC Dobson 《Australian veterinary journal》2020,98(5):216-221

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Musculoskeletal responses of 2-year-old Thoroughbred horses to early training. 4. Morphometric,microscopic and biomechanical properties of the digital tendons of the forelimb     

EC Firth  CW Rogers  BH Anderson 《New Zealand veterinary journal》2013,61(5):285-292

AIM: To determine the weight, volume, density and cross-sectional area (CSA) of the digital flexor tendons, common digital extensor tendon (CDET) and suspensory ligament (SL) of the forelimb of young Thoroughbred horses in early training, and to assess the response to a training programme of known parameters of superficial digital flexor tendon (SDFT) tissue at mid-metacarpal level.

METHODS: The tendons of seven 2-year-old Thoroughbred horses in training were inspected, transected into segments of known length, and compared with those from seven untrained horses matched for age, sex and breed. The weight, volume, density and CSA of each segment, and the crimp angle, histological features, and biomechanical ultimate stress and stiffness of tendon samples from the mid-metacarpal region of the SDFT were determined.

RESULTS: There was no macroscopic evidence of swelling or discolouration in any of the tendon segments or cut surfaces. The volumes of SDFT and CDET segments of horses in the trained group were significantly greater than those in the untrained group (p=0.036 and p=0.039, respectively). A greater increase in volume than weight resulted in a lower density in the SDFT but not CDET in trained compared with untrained horses (p=0.038). CSA of these two tendons was significantly greater in the trained group (p=0.002 and 0.036, respectively), the percentage increase being greater in the CDET than the SDFT. The number of tenocytes at four sites in the mid-metacarpal SDFT region was less in trained than untrained horses (p=0.025). There was no histological evidence of inflammation, and no difference in crimp angle between groups. There was no significant between-group difference in stiffness or ultimate stress of tendon strips.

CONCLUSIONS: Volume and CSA of the SDFT and CDET were larger in trained than untrained horses. The SDFT was less dense in the trained group. Because no evidence of tendonitis was detected and training appeared to have no significant effect on crimp angle or biomechanical properties of tendon strips, the size and density changes were presumed to be adaptive and induced by the training.

CLINICAL RELEVANCE: Although evident in this in vitro study, the detection of adaptive from initial pathological increase in size of the SDFT is likely to be difficult in vivo.  相似文献   

Evidence for new sources of NOX in the lower atmosphere     

EC Zipf  SS Prasad 《Science (New York, N.Y.)》1998,279(5348):211-213

Laboratory studies show that the reaction of short-lived O2(B3Sigmau) molecules (lifetime approximately 10 picoseconds) with N2 and the photodissociation of the N2:O2 dimer produce NOx in the stratosphere at a rate comparable to the oxidation of N2O by O(1D). This finding implies the existence of unidentified NOX sinks in the stratosphere. The NO2 observed in this experiment is isotopically heavy with a large 15N/14N enhancement. However, photodissociation of this NO2 unexpectedly produced NO molecules with a low 15N/14N ratio. The diurnal odd-nitrogen cycle in the stratosphere will be marked by a complex isotope signature that will be imprinted on the halogen and HOX catalytic cycles.  相似文献