Post-reclamation Age Effects on Soil Physical Properties and Microbial Activity Under Forest and Pasture Ecosystems     

A. Adeli  J. P. Brooks  J. J. Read  R. McGrew  J. N. Jenkins 《Communications in Soil Science and Plant Analysis》2019,50(1):20-34

During surface mining and subsequent reclamation efforts, physical, chemical, and biological properties of soils are disturbed. A study was conducted to evaluate the effects of age chronosequence on soil physical property and microbial activity in chronosequence reclaimed sites covering successional ages in the ranges 1, 4, 8, 11, and 13 years under forest and pasture ecosystems. The adjacent normal and unmined pasture and forest were used as a control for comparison purposes. The study site was located at the Red Hill Mine in east central Mississippi (approximately 33.3 N latitude and 89 W longitude), which is used by the North America Mining Company, LLC. Soil samples were collected from the reclaimed and unmined sites at 0–15- and 15–30-cm depth and analyzed for selected soil quality indicators. Results indicated that water stable aggregate and infiltration were increased, but soil bulk density and compaction decreased with increasing reclamation age. Soil penetration resistance was greater in the pasture than forest ecosystem. All reclaimed soils had less microbial enzyme activity than an unmined forest ecosystem; however, bacteria population level after 11 years since reclamation was similar to that of unmined forest soils. Soil organic carbon increased with increasing reclamation age strongly correlated with soil physical indicators and appears to be the main driving force during the development of soil physical and biological properties in the humid southeast.  相似文献   

In situ observations of a high-pressure phase of H2O Ice     

IM Chou  JG Blank  AF Goncharov  H Mao  RJ Hemley 《Science (New York, N.Y.)》1998,281(5378):809-812

A previously unknown solid phase of H2O has been identified by its peculiar growth patterns, distinct pressure-temperature melting relations, and vibrational Raman spectra. Morphologies of ice crystals and their pressure-temperature melting relations were directly observed in a hydrothermal diamond-anvil cell for H2O bulk densities between 1203 and 1257 kilograms per cubic meter at temperatures between -10 degrees and 50 degreesC. Under these conditions, four different ice forms were observed to melt: two stable phases, ice V and ice VI, and two metastable phases, ice IV and the new ice phase. The Raman spectra and crystal morphology are consistent with a disordered anisotropic structure with some similarities to ice VI.  相似文献   

Idiopathic eosinophilic meningoencephalitis in Rottweiler dogs: three cases (1992–1997)     

PF BENNETT  FJ ALLAN  WG GUILFORD  AF JULIAN  CG JOHNSTON 《Australian veterinary journal》1997,75(11):786-789

We report three cases of eosinophilic meningitis in young male Rottweiler type dogs in New Zealand. No cause for the disease was identified. There were variable clinical signs referable to central nervous system dysfunction, and a variable response to treatment.  相似文献   

Pectinate ligament dysplasia and glaucoma in Flat Coated Retrievers. II. Assessment of prevalence and heritability     

Wood JL  Lakhani KH  Read RA 《Veterinary ophthalmology》1998,1(2-3):91-99

Pectinate ligament dysplasia (PLD) in dogs is a congenital ocular abnormality affecting the iridocorneal angle, the presence of which may be associated with adult-onset primary glaucoma. This study demonstrates a significant association between PLD and glaucoma in Flat Coated Retrievers, and also a higher prevalence of PLD in Flat Coated Retrievers compared with other breeds. It is shown that the association between PLD and glaucoma was robust and not due to a small increase in PLD with age. There was also a significant association between PLD in offspring and parents and, using the offspring–parents regression, the heritability of PLD was estimated as approximately 0.7. As glaucoma is significantly related to PLD, glaucoma may also be heritable. Thus, glaucoma can be controlled by gonioscopic examination and elimination of animals with a high degree of PLD from a breeding program. Breeding from only those animals with a moderate or low PLD value or score should limit the expected prevalence of glaucoma in the resulting population to < 0.2%. The preceding study describes in detail the PLD survey, gonioscopic technique and some initial results obtained prior to this epidemiological investigation.  相似文献   

Arthrodesis of the equine proximal interphalangeal joint: a mechanical comparison of 2 parallel 5.5 mm cortical screws and 3 parallel 5.5 mm cortical screws     

Read EK  Chandler D  Wilson DG 《Veterinary surgery : VS》2005,34(2):142-147

OBJECTIVE: To compare the biomechanical characteristics and mode of failure of 2 techniques using parallel 5.5 mm screws for pastern joint arthrodesis in horses. STUDY DESIGN: Randomized block design, for horse (1-5), method of fixation (two 5.5 mm screws versus three 5.5 mm screws), side (right, left), and end (front, hind). Constructs were tested to failure in 3-point bending. SAMPLE POPULATION: Twenty limbs (5 cadavers). METHODS: A combined aiming device was used to facilitate screw placement. Two parallel 5.5 mm screws were inserted in lag fashion in 1 limb of a pair, and three 5.5 mm screws were inserted in the contralateral limb. Constructs were then tested in 3-point bending in a dorsal-to-palmar (plantar) direction using a materials testing machine at a loading rate of 19 mm/s. Maximal bending moment at failure and stiffness were obtained from bending moment-angular deformation curves. RESULTS: There was no significant difference between two and three 5.5 mm screw constructs for bending moment and stiffness (P<.05). All constructs ultimately failed by bone fracture or screw bending. For proximal interphalangeal (PIP) joint arthrodesis constructs loaded in 3-point bending, no significant effect of treatment, side, or end on maximal bending moment or stiffness was detected. CONCLUSIONS: Two 5.5 mm cortical screws inserted in parallel should provide a surgically simpler and equally strong PIP joint arthrodesis compared with three 5.5 mm cortical screws. CLINICAL RELEVANCE: Two 5.5 mm cortical screws inserted in parallel for PIP joint arthrodesis should perform similarly under conditions used in this study, as three 5.5 mm screws inserted in a similar manner, when loaded under bending.  相似文献   

Apoptosis in liver damage produced by tunicamycin     

Finnie JW  Read SH  Swift JG 《Australian veterinary journal》2004,82(1-2):87-90

OBJECTIVE: To determine whether apoptosis contributes to hepatocyte loss in tunicamycin poisoning. DESIGN: Groups of four guinea pigs were given 400 microg/kg of tunicamycin subcutaneously and killed at 24 h intervals up to 72 h post-injection. Livers were examined by routine histological methods and ancillary techniques (TUNEL staining, endonuclease activation, caspase activity, and electron microscopy) to ascertain whether any hepatocyte injury was apoptotic. RESULTS: Many hepatocytes exposed to tunicamycin showed evidence of apoptosis in the form of nuclear karyorrhexis with chromatin margination and crescent formation, TUNEL-positivity, DNA laddering, elevated caspase activity and apoptotic body formation. CONCLUSION: Tunicamycin caused the death of many hepatocytes in the livers of guinea pigs by apoptosis.  相似文献   

Optimization of sample handling and processing for the carbon 13-labeled aminopyrine demethylation blood test and determination of a reference range for test results in healthy dogs   总被引：1，自引：0，他引：1  

DeBiasio JV  Steiner JM  Suchodolski JS  Read SA 《American journal of veterinary research》2008,69(11):1385-1390

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Biological soil crust distribution is related to patterns of fragmentation and landuse in a dryland agricultural landscape of southern Australia   总被引：2，自引：0，他引：2  

Cassia F. Read  David H. Duncan  Peter A. Vesk  Jane Elith 《Landscape Ecology》2008,23(9):1093-1105

The dryland agricultural landscape of north-west Victoria, Australia, includes isolated remnants of eucalypt woodland that are exposed to ongoing disturbance from sheep grazing and cropping activity. Biological soil crusts are a functionally important feature of these woodland communities. We used a modern form of regression (boosted regression tree (BRT) models) to investigate relationships between crust abundance and environmental and landscape variables. We also investigated whether the use of broad morphological groups of crust organisms is more informative than simply measuring total crust cover. Remnant size was the single most influential variable for crust abundance, with negligible crust cover in small patches (<5 ha). The BRT model also identified relationships between crust abundance and available P, soil C and perennial grass. We argue that disturbance from stock grazing and camping is the mechanism driving these relationships. Other variables related to crust abundance were proximity to the windward edge, litter cover and tree cover. Morphological groups showed a differential response to some variables, suggesting assessment of total cover may mask important patterns in community structure. Crust disturbance represents a serious issue for maintenance of ecosystem function in the study region, particularly loss of crusts from small remnants because the majority of remnants are small.  相似文献   

Clinical and epidemiological features of West Nile virus equine encephalitis in New South Wales,Australia, 2011     

AJ Read  DS Finlaison  X Gu  PM Hick  BJ Moloney  T Wright  PD Kirkland 《Australian veterinary journal》2019,97(5):133-143

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Stolon Development and Cultural Production Practices of Winter-Grown Strawberries     

Donna M. Morrison  Erin E. Blankenship  Paul E. Read  Ellen T. Paparozzi 《International Journal of Fruit Science》2018,18(2):138-152

ABSTRACT

The four experiments described here are part of a 5-year program focused on determining whether day-neutral and short-day strawberries would be suitable for commercial off-season/winter (temperate climate) production in greenhouses. All research was performed using container-grown plants fertigated through a capillary mat production system with heat supplied under the benches. The first experiment focused on stolon development. The second experiment investigated the influence of stolon removal on berry production and included the removal of flowers for the first three weeks. The third and fourth experiments were conducted as a comparison of university research (experiment 3) versus a commercial operation (experiment 4). In experiment one, of 13 cultivars, ‘AC Wendy’ plants produced significantly more stolons than the other cultivars. In experiment two, stolon production peaked at weeks 12 and 13, with ‘Chandler’ plants producing significantly more stolons (starting at week 9) than the other cultivars. At week 13, ‘Seascape’ plants produced more total berry weight than the other cultivars. The influence of stolon removal on total berry weight varied, with ‘Evie-2+’ plants (large crowns) producing higher total berry weight with the stolons on as compared to ‘Evie-2’ plants, which produced higher total berry weight with the stolons removed. In experiment 2, fruit production was low and was probably a result of deflowering for three weeks. Consequently, it may not be advisable to deflower during the ‘off-season’ for greenhouse-grown strawberries. In the final two experiments, which involved a commercial cooperator as well as the university greenhouse, it was found that of the five cultivars trialed, the same cultivars at both sites produced the maximum total berry weight. Stolon production differed at the two locations, but the optimal time for stolon removal was similar. Thus, it is recommended that for winter greenhouse production, stolons be removed initially at week 8 and then at weeks 11–12 of the production cycle.  相似文献