Effect of a second treatment of prostaglandin F2α during the Ovsynch program on fixed-time artificial insemination conception rates and luteolysis in split-calving,pasture-fed dairy cows     

JM Rheinberger  DD Colson  DS Beggs  PD Mansell  MA Stevenson  RJ Rheinberger  MF Pyman 《Australian veterinary journal》2020,98(5):190-196

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The radio-frequency single-electron transistor (RF-SET): A fast and ultrasensitive electrometer     

RJ Schoelkopf  P Wahlgren  AA Kozhevnikov  P Delsing  DE Prober 《Science (New York, N.Y.)》1998,280(5367):1238-1242

A new type of electrometer is described that uses a single-electron transistor (SET) and that allows large operating speeds and extremely high charge sensitivity. The SET readout was accomplished by measuring the damping of a 1.7-gigahertz resonant circuit in which the device is embedded, and in some ways is the electrostatic "dual" of the well-known radio-frequency superconducting quantum interference device. The device is more than two orders of magnitude faster than previous single-electron devices, with a constant gain from dc to greater than 100 megahertz. For a still-unoptimized device, a charge sensitivity of 1.2 x 10(-5) e/hertz was obtained at a frequency of 1.1 megahertz, which is about an order of magnitude better than a typical, 1/f-noise-limited SET, and corresponds to an energy sensitivity (in joules per hertz) of about 41 Planck's over 2pi.  相似文献   

Oceanic Anoxia and the End Permian Mass Extinction   总被引：6，自引：0，他引：6  

PB Wignall  RJ Twitchett 《Science (New York, N.Y.)》1996,272(5265):1155-1158

Data on rocks from Spitsbergen and the equatorial sections of Italy and Slovenia indicate that the world's oceans became anoxic at both low and high paleolatitudes in the Late Permian. Such conditions may have been responsible for the mass extinction at this time. This event affected a wide range of shelf depths and extended into shallow water well above the storm wave base.  相似文献   

Arthropod-transmitted infectious diseases of cats     

SE Shaw  RJ Birtles  MJ Day 《Journal of Feline Medicine and Surgery》2001,3(4):193-209

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Cross‐sectional survey of health management and prevalence of vector‐borne diseases,endoparasites and ectoparasites in Samoan dogs          下载免费PDF全文

RJ Carslake  KE Hill  K Sjölander  SF Hii  D Prattley  E Acke 《Australian veterinary journal》2017,95(12):462-468

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Epizootics of sudden death in tammar wallabies (Macropus eugenii) associated with an orbivirus infection     

KA Rose  PD Kirkland  RJ Davis  D Blumstein  LI Pritchard  KM Newberry  RA Lunt 《Australian veterinary journal》2012,90(12)

Epizootics of sudden death in tammar wallabies (Macropus eugenii) occurred at six research facilities and zoological gardens in New South Wales, Australia, in late 1998 and at one Queensland research facility in March 1999. There were 120 confirmed tammar wallaby deaths during this period; however, population censuses indicated that up to 230 tammar wallabies may have died. The majority of animals died without premonitory signs. A small proportion of wallabies exhibited increased respiratory rate, sat with a lowered head shortly before death or were discovered in lateral recumbency, moribund and with muscle fasciculations. Gross postmortem findings consistently included massive pulmonary congestion, mottled hepatic parenchyma and subcutaneous oedema throughout the hindlimbs and inguinal region. Approximately 30% of the animals examined also had extensive haemorrhage within the fascial planes and skeletal muscle of the hindlimb adductors, inguinal region, ventral thorax, dorsal cervical region and perirenal retroperitoneal area. The tissues of affected animals became autolytic within a short period after death. Bacteriological examination of tissues from 14 animals did not provide any significant findings. Toxicological examination of the gastric and colonic contents of four animals did not reveal evidence of brodifacoume or other rodenticides. Viruses from the Eubenangee serogroup of the Orbivirus genus were isolated from the cerebral cortex of nine, and the myocardium of two, tammar wallabies and the liver and intestine of another tammar wallaby. A similar orbivirus was also isolated from the cerebrospinal fluid of another tammar wallaby that died suddenly. The disease agent appears to be a previously unrecognised orbivirus in the Eubenangee serogroup. This is the first report of epizootics of sudden deaths in tammar wallabies apparently associated with an orbivirus infection.  相似文献   

Actin polymerization enhances Pasteurella haemolytica leukotoxicity     

Basaraba RJ  Byerly AN  Mosier DA  Butine MD  Stewart GC  Fenwick BW  Chengappa MM  Highlander SK 《Veterinary microbiology》1999,64(4):307-321

Pasteurella haemolytica leukotoxin is cytotoxic to bovine leukocytes, causing increased cell membrane permeability, osmotic swelling, release of cytosolic proteins and cell lysis. These studies were designed to test if leukotoxin causes release of the cytoskeletal protein, actin, from bovine leukemia cells and if purified actin-influenced bacterial growth or leukotoxin production. Culture supernatants caused a 7-fold decrease in viability of bovine leukemia cells and increased cell permeability that was accompanied by release of beta-actin into the cell culture supernatant. Exposing P. haemolytica to purified actin solutions induced the conversion of monomeric G-actin to polymerized F-actin. This conversion was partially inhibited by bovine P. haemolytica immune, but not pre-immune, serum. Loss of streptomycin resistance following treatment of the organism with acridine orange ablated the polymerizing activity. Incubation of P. haemolytica in the presence of purified F-actin did not affect growth but resulted in culture supernatant that had 3.0-3.9-fold greater leukotoxicity compared to medium alone or medium containing G-actin, heat-denatured actin or albumin. The effect of actin on leukotoxicity was concentration-dependent and directly associated with increases in secreted leukotoxin. The interaction between P. haemolytica and actin is potentially detrimental to the host by inducing polymerization of actin into insoluble filaments and by enhancing leukotoxicity.  相似文献   

A technique for the photography of surface morphology of bacterial colonies     

RJ CAMPBELL 《Australian veterinary journal》1989,66(9):303-304

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Some characteristics of a recent virulent isolate of Marek's disease virus   总被引：1，自引：0，他引：1  

M ZERBES  GA TANNOCK  RJ JENNER  PL YOUNG 《Australian veterinary journal》1994,71(1):21-22

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Vesicles Cytoplasmic Injection: An Efficient Technique to Produce Porcine Transgene‐Expressing Embryos          下载免费PDF全文

CG Luchetti  RJ Bevacqua  MS Lorenzo  MF Tello  M Willis  CP Buemo  DM Lombardo  DF Salamone 《Reproduction in domestic animals》2016,51(4):501-508

The use of vesicles co‐incubated with plasmids showed to improve the efficiency of cytoplasmic injection of transgenes in cattle. Here, this technique was tested as a simplified alternative for transgenes delivery in porcine zygotes. To this aim, cytoplasmic injection of the plasmid alone was compared to the injection with plasmids co‐incubated with vesicles both in diploid parthenogenic and IVF zygotes. The plasmid pcx‐egfp was injected circular (CP) at 3, 30 and 300 ng/μl and linear (LP) at 30 ng/μl. The experimental groups using parthenogenetic zygotes were as follows: CP naked at 3 ng/μl (N = 105), 30 ng/μl (N = 95) and 300 ng/μl (N = 65); Sham (N = 105); control not injected (N = 223); LP naked at 30 ng/μl (N = 78); LP vesicles (N = 115) and Sham vesicles (N = 59). For IVF zygotes: LP naked (N = 44) LP vesicles (N = 94), Sham (N = 59) and control (N = 79). Cleavage, blastocyst and GFP+ rates were analysed by Fisher's test (p < 0.05). The parthenogenic CP naked group showed lower cleavage respect to control (p < 0.05). The highest concentration of plasmids to allow development to blastocyst stage was 30 ng/μl. There were no differences in DNA fragmentation between groups. The parthenogenic LP naked group resulted in high GFP rates (46%) and also allowed the production of GFP blastocysts (33%). The cytoplasmic injection with LP vesicles into parthenogenic zygotes allowed 100% GFP blastocysts. Injected IVF showed higher cleavage rates than control (p < 0.05). In IVF zygotes, only the use of vesicles produced GFP blastocysts. The use of vesicles co‐incubated with plasmids improves the transgene expression efficiency for cytoplasmic injection in porcine zygotes and constitutes a simple technique for easy delivery of plasmids.  相似文献