Anthrax in cattle in southern Western Australia     

D. FORSHAW  ARB HIGGS  DC MOIR  TM ELLIS  IJ LINKS 《Australian veterinary journal》1996,74(5):391-393

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Behavioural and EEG changes in sheep in response to painful acute electrical stimuli     

RM ONG  JP MORRIS  JK O'DWYER  JL BARNETT  PH HEMSWORTH  IJ CLARKE 《Australian veterinary journal》1997,75(3):189-193

Objective To measure acute pain in sheep, based on a human pain model, and examined changes in both electroencephalogram frequency spectrum and behavioural responses to increased electrical stimulation in sheep. Design Analysis of variance (treatment and animal effects) for stimulus intensity where each animal received each electric shock treatment given in the order 0, 5,10 and 20 mA. Procedure Eight sheep with electrodes implanted over the surface of the brain were examined for escape-avoidance and electroencephalogram responses to four levels of electrical stimulation from 0–20 mA. Results With increasing stimulus intensity at the time of feeding, the sheep were more hesitant to return to the feeder or remain near the feeder following stimulation. There was little difference between the 0 and 5 mA stimuli for any of the behaviour variables (P > 0.05). However, there were marked increases in the time taken to re-approach the feeder after receiving an electric shock of 5 mA and of 20 mA (P < 0.05; mean values 3 and 119 s, respectively) and remaining near the feeder for 5 s (P < 0.001; mean values 10 and 167 s, respectively). Following the stimulus, there was an overall increase in the electroencephalogram power spectrum in the first four seconds, which then rapidly returned to normal. In particular, the 20 mA stimulus resulted in higher absolute power values than in the control (0 mA) treatment for delta 2 (P < 0.001), theta 1 (P < 0.05), theta 2 (P < 0.05), alpha 1 (P < 0.001), alpha 2 (P < 0.001) and beta 1 (P < 0.01) band-widths. Similarly, for the 10 mA stimulus, the absolute power values were greater than the control treatment for delta 2 (P < 0.05), alpha 1 (P < 0.01), alpha 2 (P < 0.001) and beta 1 (P < 0.01) bandwidths. Conclusion The experiment suggests that a human acute pain model is applicable to sheep and that these electroencephalogram changes may provide a good measure of acute pain in sheep.  相似文献   

Across-country genomic predictions in Norwegian and New Zealand Composite sheep populations with similar development history     

Hinayah Rojas de Oliveira  John C. McEwan  Jette H. Jakobsen  Thor Blichfeldt  Theo H. E. Meuwissen  Natalie K. Pickering  Shannon M. Clarke  Luiz F. Brito 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2022,139(1):1-12

The goal of this study was to assess the feasibility of across-country genomic predictions in Norwegian White Sheep (NWS) and New Zealand Composite (NZC) sheep populations with similar development history. Different training populations were evaluated (i.e., including only NWS or NZC, or combining both populations). Predictions were performed using the actual phenotypes (normalized) and the single-step GBLUP via Bayesian inference. Genotyped NWS animals born in 2016 (N = 267) were used to assess the accuracy and bias of genomic estimated breeding values (GEBVs) predicted for birth weight (BW), weaning weight (WW), carcass weight (CW), EUROP carcass classification (EUC), and EUROP fat grading (EUF). The accuracy and bias of GEBVs differed across traits and training population used. For instance, the GEBV accuracies ranged from 0.13 (BW) to 0.44 (EUC) for GEBVs predicted including only NWS, from 0.06 (BW) to 0.15 (CW) when including only NZC, and from 0.10 (BW) to 0.41 (EUC) when including both NWS and NZC animals in the training population. The regression coefficients used to assess the spread of GEBVs (bias) ranged from 0.26 (BW) to 0.64 (EUF) for only NWS, 0.10 (EUC) to 0.52 (CW) for only NZC, and from 0.42 (WW) to 2.23 (EUC) for both NWS and NZC in the training population. Our findings suggest that across-country genomic predictions based on ssGBLUP might be possible for NWS and NZC, especially for novel traits.  相似文献   

Partial incompatibility in crosses between Hordeum vulgare L. and H. bulbosum L.     

R. A. Pickering  J. D. Hayes 《Euphytica》1976,25(1):671-678

Summary Certain cultivars of Hordeum vulgare L. gave low seed set (average <30%) after pollination with H. bulbosum, while others consistently gave high seed set (average >80%). The reduced seed setting occurred in crosses with cultivars which had H. distichum var. laevigatum in their ancestry. The results show that the reduced setting is probably controlled by a single dominant gene. This finding is of particular importance to breeders concerned with the use of Vada or some of its high yielding derivatives for producing haploids by interspecific hybridization.  相似文献   

Specific sorption of antimony (III) by the hydrous oxides of Mn,Fe, and Al     

P. Thanabalasingam  W. F. Pickering 《Water, air, and soil pollution》1990,49(1-2):175-185

The hydrous oxides of Mn, Fe, and Al avidly sorbed Sb from μM Sb(OH), solutions, with uptake levelling off as initial Sb concentration increased. Capacity values decreased along the sequence MnOOH > Al(OH)₃ > FeOOH. The amount sorbed by each substrate decreased gradually at pH values > 6. Addition of 0.4M CH₃COONa to the aqueous phase (to minimise retention of weakly bound Sb) had little effect on MnOOH uptake capacity (～160 mmol, kg^?1 at pH < 7) but retention dropped rapidly at higher pH. With the other two substrates (pH 6–7) the calculated capacity values for specific Sb sorption were ～ 45 mmol kg^?1 FeOOH and ～ 33 mmol kg^? Al(OH)₃; about a third of the total capacity values. On these substrates specific Sb sorption tended to peak in the pH 7 to 8 region. The pH response pattern was modified using Sb tartrate sorbate solutions. Factors influencing Sb sorption included substrate surface charge, chemical form of Sb and surface interactions. Formation of a sparingly soluble metal coating was indicated by the uptake plateaus observed when increasing amounts of solid were added to Sb solutions containing acetate.  相似文献   

Extraction of metal ions sorbed on hydrous oxides of iron(III)     

J. Slavek  W.F. Pickering 《Water, air, and soil pollution》1986,28(1-2):151-162

Extraction of metal ions presorbed on Fe(III) hydrous oxide suspensions using 20 different chemical reagents has confirmed that bonding to several different sites can be involved. Up to half of the sorbed Cd was moderately weakly bound, and was displaced by Mg, Ca and Na chloride solutions but these reagents released little Cu or Pb, and < 20% of the Zn. Reagents which partially dissolved gel suspensions (e.g. mineral acids, EDTA, reducing agents) released > 80% of the sorbed metal ion, but a small fraction remained as a limited solubility interaction product in each case. Sorption and extraction behavior using samples containing goethite and/or hematite reflected the lower solubility of these solids in the various solutions. ‘Aged’ gels bound metal ions less strongly than freshly precipitated hydrous oxide. The extraction data has been interpreted in terms of displacement reactions, formation of complex ions, and specific adsorption (or coprecipitation). The significance of hydrous oxide formation in metal ion scavenging from natural waters and subsequent release processes has been considered.  相似文献   

The effect of ion exchange on the solubility of fluoride compounds     

W. F. Pickering  J. Slavek  P. Waller 《Water, air, and soil pollution》1988,39(3-4):323-336

The influence of ion exchange processes on the apparent solubility of fluoride compounds was examined by observing changes in free F^? and total F levels when suspensions of sparingly soluble fluoride species (e.g., CaF₂, AlF₃) and aluminium smelter wastes were equilibrated with a range of materials having different cation exchange capacities. The exchanger materials used included synthetic resins, clay minerals, a humic acid and Mn(IV) oxide. The amount of fluoride ion released from the fluoride salts and F^? rich wastes was found to increase in the presence of solids capable of exchanging cations, and the magnitude of the effect tended to be determined by the number of exchange sites available and the affinity of the fluoride compound cation for the exchange material. In some instances (e.g., with illite and alumina wastes) the released fluoride ion attacked the substrate and formed soluble complex ions.  相似文献   

Influence of clay-solute interactions on aqueous heavy metal ion levels     

Helen Farrah  W. F. Pickering 《Water, air, and soil pollution》1977,8(2):189-197

The extent to which heavy metal ions (Cu, Pb, Zn, Cd) are removed from aqueous solution by clay suspensions (kaolinite, illite or montmorillonite) has been shown to vary with the nature of the clay, solution pH, concentration of competing cations, and the nature (and concentration) of any ligands present. The amount sorbed increases gradually with pH until the threshold value for formation of sparingly soluble hydroxy complexes is reached. The affinity order for divalent cations, and the nature of the sorption process also appear to vary with clay type.  相似文献   

Interaction of clays with dilute fluoride solutions     

J. Slavek  H. Farrah  W. F. Pickering 《Water, air, and soil pollution》1984,23(2):209-220

Interaction between dilute (mg L^?1) NaF solutions and clay suspensions (0.08 % w/v) has been examined as a function of pH (range 3 to 8), clay type (Na⁺- or Ca²⁺-kaolinite, illite, montmorillonite) and NaF concentration. No F loss from solution was detected at pH > 6.5, while enhanced uptake was found on decreasing the pH, especially in the 4 to 3 region. Removal of F from 1 to 6 × 10^?4 M NaF was only slightly dependent on weight of solid, but did increase with [F^?]. It is proposed that F losses are due to the formation of sparingly soluble Al species (e.g. cryolite, Na fluoro silicate), occasionally augmented with CaF₂ formation (Ca²⁺-clays). The Al is released by proton attack on the lattice, following conversion of the suspended solids into the unstable H⁺-form, either through acid addition (pH < 5) or through hydrolysis of the Na⁺-form material. The latter process was most pronounced with the illite and montmorillonite samples. The amount of F fixed by montmorillonite was roughly double that held by the other two clays, and had a maximum value (pH 3) of ～ 4 mg g^?1, using 11 mg L^?1 NaF solutions. Soluble fluoro-complexes, similar in quantity to the retained F, were detected, in many of the studies. It was concluded that contact of the clay components of soils or sediments with mg L^?1 levels of F in adjacent aqueous phases would result in only a minor proportion being retained.  相似文献   

TIME-SERVICE OF HARVARD COLLEGE OBSERVATORY     

Pickering EC 《Science (New York, N.Y.)》1892,19(471):87-89

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