c-axis electrodynamics as evidence for the interlayer theory of high-temperature superconductivity     

PW Anderson 《Science (New York, N.Y.)》1998,279(5354):1196-1198

In the interlayer theory of high-temperature superconductivity, the interlayer pair tunneling energy (similar to the Josephson or Lawrence-Doniach energy) is the motivation for superconductivity. This connection requires two experimentally verifiable identities: the coherent normal-state conductance must be smaller than the "Josephson" coupling energy, and the Josephson coupling energy must be equal to the condensation energy of the superconductor. The first condition is well satisfied in the only case that is relevant, (La, Sr)2CuO4, but the second condition has been questioned. It is satisfied for all dopings in (La,Sr)2CuO4 and also in optimally doped Hg(Ba)2CuO5, which was measured recently, but seems to be strongly violated in measurements on single crystals of Tl2Ba2CuO6.  相似文献   

Diseases of young captive crocodiles in Papua New Guinea     

P W Ladds  L D Sims 《Australian veterinary journal》1990,67(9):323-330

To identify causes of mortality in young captive crocodiles, detailed necropsy and laboratory examination was done on 54 (30 Crocodylus porosus, 22 C. novaeguineae, 2 of unrecorded species). Although multiple infections often confounded interpretation it was concluded that the major infectious diseases, of approximately equal importance, were coccidiosis, bacterial septicaemia with Gram-negative organisms, and metazoan parasitism including ascariasis and pentastomiasis. A range of other lesions and agents was recognised, including keratitis, enteritis of unknown aetiology, non-suppurative encephalitis, traumatic peritonitis and trematodes located in renal tubules, gut and blood vessels. Some crocodiles in poor condition had only mild lesions associated with metazoan parasites and the cause of death or illness could not be clearly determined, although it was considered likely that adaptation failure was a contributing factor.  相似文献   

Neoplasms of the skin of dogs in tropical Queensland     

P W Ladds  H Kraft  A Sokale  K F Trueman 《Australian veterinary journal》1983,60(3):87-88

  相似文献   

THE VALUE OF COMPLEMENT FIXATION TESTING OF SLAUGHTER CATTLE IN SURVEYING THE INCIDENCE OF BOVINE CONTAGIOUS PLEUROPNEUMONIA     

P. W. Ladds  B.V.Sc. 《Australian veterinary journal》1965,41(12):387-390

  相似文献   

PREGNANCY IN SLAUGHTERED COWS IN NORTH-EASTERN AUSTRALIA     

P. W. Ladds  M.V.Sc.  Ph.D.  P. M. Summers  B.V.Sc.  M.Sc. J. D. Humphrey  B.V.Sc.  M.Sc. 《Australian veterinary journal》1975,51(10):472-477

A total of 7495 postpuberal beef cows from herds in north Queensland and the Northern Territory were examined at abattoirs to define the extent of wastage due to the slaughter of pregnant cows. On the basis of examination of teeth most cows (57%) were considered mature (approximately 3.5 to 7 years) at slaughter; 14% were young (9 months to 3.5 years) and 29% were old (over 7 years). In herds where pregnancy diagnosis by rectal examination had not been used at time of culling, 71.6% of slaughtered cows were pregnant and 42% of these cows were in the second trimester. This high pregnancy rate was considered an important source of herd wastage. Pregnancy rate varied little with season, but the highest percentages of cows pregnant in the first and third trimesters were recorded in autumn and spring, respectively. Most cows found non-pregnant had active ovaries at time of slaughter. Anoestrus was observed to be most common in winter and in old cows. Lactational status was not recorded. Mean cold carcase weight of 4229 cows was 161 +/- 40 kg. Maximum carcase weight was observed in cows slaughtered at 4 to 6 years of age; old cows had the lowest carcase weight (147 +/- 31 kg) of the age groups considered. Highest (170 +/- 43 kg) and lowest (135 +/- 41 kg) carcase weights in relation to pregnancy or ovarian status were observed in non-pregnant/ovary-active and non-pregnant/anoestrus cows respectively. Carcase weight of cows in the third trimester (165 +/- 35 kg) was greater than in the second (161 +/- 35 kg) or first (157 +/- 36 kg) trimesters; difference between the first and third trimesters was significant (P less than 0.01).  相似文献   

EPIDEMIOLOGICAL AND GROSS PATHOLOGICAL STUDIES OF ONCHOCERCA GIBSONI INFECTION IN CATTLE     

P.W. Ladds    S. Nitisuwirjo  M.E. Goddard 《Australian veterinary journal》1979,55(10):455-462

SUMMARY A total of 5712 cattle from 62 properties or localities in northern, central and eastern Australia were examined at abattoirs, and the presence of Onchocerca gibsoni infection was related to region, season when slaughtered, and breed, sex and age of slaughtered cattle. Additionally, these features were also related to nodule characteristics determined from macroscopic examination of all nodules in single (left or right) briskets from 1287 infected cattle selected at random from those examined in abattoirs. Infection rate was 86% and number of nodules per brisket was 3.7 ± 4.1 (Mean ± Standard Deviation). When adjusted for other variables infection rates varied from 18% in central New South Wales to a maximum of 96% in north western Queensland. Number of nodules per brisket in cattle from north western Queensland was 9 times greater than in cattle from central New South Wales. Most nodules (70%) were 1–2 cm in diameter and weighed less than 2 g. The occurrence of changes such as calcification and caseation indicated that 20–30% of nodules studied were undergoing advanced degeneration or resolution. More nodules were detected in autumn than during winter or spring and the proportions of nodules which were hard on palpation, or had thick capsules, both increased during the autumn-spring interval. Although inconclusive, breed differences observed suggested that Bos indicus and B. indicus crossbreds had slightly greater resistance to O. gibsoni infection than cattle of British breed. Infection rate and number of nodules per brisket were greater in bulls than in cows or steers but weight of nodules in steers was greater than in other groups. Percentage of animals infected, and nodule prevalence both increased with increasing age but annual increase in nodule prevalence was less in cattle over 5 years than in younger ones, suggesting development of some immunity in mature cattle.  相似文献   

Seminoma in a southern white rhinoceros (Ceratotherium simum simum)     

Portas TJ  Hermes R  Bryant BR  Göritz F  Ladds P  Hildebrant TB 《The Veterinary record》2005,157(18):556-558

  相似文献   

Soil and agronomic factors associated with cadmium accumulations in kidneys of grazing sheep     

PW MORCOMBE  DS PETTERSON  PJ ROSS†  JR EDWARDS 《Australian veterinary journal》1994,71(12):404-406

SUMMARY Mean concentration of cadmium (Cd) in kidneys of hogget sheep from 67 flocks grazing in the Agricultural Region of Western Australia was tested for association with soil, pastoral, climatic and nutritional factors. Hoggets grazing pastures on acidic soils and soils with a sandy-textured surface had higher Cd concentrations in kidneys than hoggets grazing pastures on more alkaline soils or soils with a clay-textured surface. Application of more than 100 kg of phosphatic fertiliser during the past 3 years to loamy soils was also associated with greater Cd concentration in kidneys of the grazing animals.  相似文献   

Susceptibility of cats to equine morbillivirus   总被引：7，自引：0，他引：7  

HA WESTBURY  PT HOOPER  SL BROUWER  PW SELLECK 《Australian veterinary journal》1996,74(2):132-134

Objective To assess the susceptibility of cats to equine morbillivirus (EMV) by direct administration of the virus by subcutaneous, intra-nasal or oral routes, and following exposure to infected cats.
Design A disease transmission study, with controls, using ten cats.
Procedure Groups of cats were given the virus by the designated methods and assessed for evidence of infection by clinical examination, plus pathological and virological tests.
Results All cats administered the virus by subcutaneous, intra-nasal or oral routes became infected and developed the disease within 4 to 8 days. One of two cats in contact with affected cats also developed the disease, but two cats kept near to affected cats did not become infected. The virus was isolated from a range of tissues collected from the infected cats, and the lesions observed in affected cats were similar to those previously observed in horses naturally and experimentally infected with the virus.
Conclusion This is the first demonstration that animals can be infected with EMV by non-parenteral means, that the virus can transmit naturally between animals and confirms other reports of the similarity of EMV disease in horses and cats.  相似文献   

Settling of insecticide from dip wash mixed with dam water and zinc sulphate and used to control sheep lice (Bovicola ovis)     

PW MORCOMBE  DF HIDE†  GE YOUNG  EW ARMSTRONG‡  LE MILLAR§  ARB HIGGS¶ 《Australian veterinary journal》1995,72(11):411-414

SUMMARY Insecticidal dipping fluid emulsions, mixed in vitro in dam water containing suspended clay particles and 1% w/v zinc sulphate, were analysed to determine rates of settling of diazinon, cyhalothrin and cypermethrin. Fifteen minutes after mixing, the concentration of the insecticides 5 cm below the surface had declined by 72.5%, 72.8% and 89.4%, respectively. On remixing, the concentration of insecticide in suspension was close to or greater than the initial concentration. In 2 trials, lice were eradicated from sheep showered with dip wash mixed in cloudy dam water to which 1% w/v of zinc sulphate was added. In 12 flock treatments in which 1000 to 2000 sheep were dipped with added zinc sulphate, the concentration of insecticide remained above the minimum lethal for susceptible strains of lice. However, lice were still present 6 months later in 8 of these flocks. When zinc sulphate is added to dip wash, agitation is needed to maintain the insecticide in suspension.  相似文献