Radio control of ventricular contraction in experimental heart block     

VERZEANO M  WEBB RC  KELLY M 《Science (New York, N.Y.)》1958,128(3330):1003-1005

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Radar detection of the nucleus and coma of comet hyakutake     

JK Harmon  SJ Ostro  LAM Benner  KD Rosema  RF Jurgens  R Winkler  DK Yeomans  D Choate  R Cormier  JD Giorgini  DL Mitchell  PW Chodas  R Rose  D Kelley  MA Slade  ML Thomas 《Science (New York, N.Y.)》1997,278(5345):1921-1924

Radar observations of comet Hyakutake (C/1996 B2) made at the Goldstone Deep Space Communications Complex in California have detected echoes from the nucleus and from large grains in the inner coma. The nucleus of this bright comet was estimated to be only 2 to 3 kilometers in diameter. Models of the coma echo indicate backscatter from porous, centimeter-size grains ejected anisotropically at velocities of tens of meters per second. The radar observations suggest that a comet's activity may be a poor indicator of its size and provide evidence that large grains constitute an important component of the mass loss from a typical active comet.  相似文献   

Induced emigrations among small mammals     

CALHOUN JB  WEBB WL 《Science (New York, N.Y.)》1953,117(3040):358-360

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The Effects of Atropine and Glycopyrrolate on Heart Rates in Conscious Mature Goats     

LUISITO S. PABLO DVM  MS  Diplomate ACVA    ALISTAIR I. WEBB BVSC  PhD  FRCVS  Diplomate ACVA  WALTER T. McNICHOLAS JR  DVM 《Veterinary surgery : VS》1995,24(6):531-534

The effects of intravenously administered atropine (0.2 mg/kg) and glycopyrrolate (0.01 mg/kg) on heart rate were studied in 10 conscious mature goats. In a drug cross-over fashion, either atropine, glycopyrrolate, or 0.9% saline solution was administered using the same volume (0.05 mL/kg). Atropine and glycopyrrolate caused a significant increase in heart rate ( P <.05), whereas saline solution (0.09%) did not. The mean percent changes in heart rate from baseline were similar for atropine and glycopyrrolate up to 14 minutes after administration. Thereafter, glycopyrrolate had a significantly greater mean change in heart rate than atropine, ie, up to 29 minutes ( P <.05). Within the atropine group, the mean percentage changes in heart rate became significantly lower compared with the initial increase (1 minute) starting at 11 minutes. For the glycopyrrolate group, the mean percent changes became significantly lower starting at 27 minutes. Glycopyrrolate and atropine had a mean percentage change in heart rate of greater than 1.0%, up to 31 and 22 minutes, respectively. At the doses used, glycopyrrolate had longer duration of action than atropine but the magnitude of increase was similar.  相似文献   

Reasons for liking and choosing a cat as a pet     

AL PODBERSCEK  JK BLACKSHAW 《Australian veterinary journal》1988,65(10):332-333

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Analytical Diagnostic Peritoneal Lavage in the Diagnosis of Intra-abdominal Injury     

Thompson DC  Pearce WJ  Longerbeam JK 《Veterinary surgery : VS》1985,14(4):327-327

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Caprine herpesvirus from balanoposthitis   总被引：4，自引：0，他引：4  

S. TARIGAN  R. F. WEBB  D. KIRKLAND 《Australian veterinary journal》1987,64(10):321-321

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Efficacy of erythromycin compared with penicillin/streptomycin for the treatment of virulent footrot in sheep   总被引：2，自引：0，他引：2  

JK WEBB WARE  CJ SCRIVENER  AL VIZARD 《Australian veterinary journal》1994,71(3):88-89

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Estimating the mass of asteroid 253 mathilde from tracking data during the NEAR flyby   总被引：1，自引：0，他引：1  

DK Yeomans  J Barriot  DW Dunham  RW Farquhar  JD Giorgini  CE Helfrich  AS Konopliv  JV McAdams  JK Miller  WM Owen  DJ Scheeres  SP Synnott  BG Williams 《Science (New York, N.Y.)》1997,278(5346):2106-2109

The terminal navigation of the Near Earth Asteroid Rendezvous (NEAR) spacecraft during its close flyby of asteroid 253 Mathilde involved coordinated efforts to determine the heliocentric orbits of the spacecraft and Mathilde and then to determine the relative trajectory of the spacecraft with respect to Mathilde. The gravitational perturbation of Mathilde on the passing spacecraft was apparent in the spacecraft tracking data. As a result of the accurate targeting achieved, these data could be used to determine Mathilde's mass as 1.033 (+/- 0.044) x 10(20) grams. Coupled with a volume estimate provided by the NEAR imaging team, this mass suggests a low bulk density for Mathilde of 1.3 grams per cubic centimeter.  相似文献   

The confidential enquiry into perioperative equine fatalities (CEPEF): mortality results of Phases 1 and 2   总被引：3，自引：0，他引：3  

GM Johnston  JK Eastment  JLN Wood  & PM Taylor 《Veterinary anaesthesia and analgesia》2002,29(4):159-170

Objectives To document the equine perioperative mortality rate and to highlight any factor associated with an increased risk of death up to 7 days after anaesthesia. Study design A prospective observational epidemiological multicentre study. Methods Data were recorded from all equidae undergoing general anaesthesia in 62 clinics. Power calculations indicated that 45 000 cases were required to detect the significance of important variables. Details of each horse, operation, anaesthetic agents and clinic personnel were recorded. Outcome at 7 days was recorded as: alive, put to sleep (PTS) or dead. Data were analysed by a standard multilevel logistic regression approach, considering the effects of clustering at the level of clinic. Results Data were collected from 41 824 cases over 6 years. A total of 39 025 (93.3%) were alive on day 7 and 785 were dead giving an overall death rate of 1.9% (95% CI: 1.8–2.0) and 2014 (4.8%) were PTS. About 5846 horses undergoing emergency abdominal surgeries (‘colics’) were excluded from subsequent analyses. A total of 35 107 ‘noncolic’ horses were alive at 7 days and 328 dead giving a death rate for noncolics of 0.9% (95% CI: 0.8–1.0). Five hundred and forty‐three (1.5%) noncolic horses classified PTS were excluded from further analyses. There were 109 (33%) deaths from cardiac arrest or post‐operative cardiovascular collapse, with 107 (32%) from fractures and myopathies. Fracture repair, out of hours surgery, and age below 1 month was associated with increased risk of dying whereas the use of acepromazine and intravenous anaesthetic agent maintenance of anaesthesia was associated with reduced risk. Conclusions A number of potential contributors to the high risk of anaesthetic‐related mortality have been identified. Further investigation of the underlying mechanism for their apparent harmful effects and development of alternative techniques is merited.  相似文献