Early Canadian microscopists with associations to veterinary medicine          下载免费PDF全文

Dukes TW 《The Canadian veterinary journal. La revue veterinaire canadienne》1993,34(4):241-245

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Retrospective Evaluation of the Effect of Heart Rate on Survival in Dogs with Atrial Fibrillation          下载免费PDF全文

B. Pedro  J. Dukes‐McEwan  M.A. Oyama  M.S. Kraus  A.R. Gelzer 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2018,32(1):86-92

Background

Atrial fibrillation (AF) usually is associated with a rapid ventricular rate. The optimal heart rate (HR) during AF is unknown.

Hypothesis/Objectives

Heart rate affects survival in dogs with chronic AF.

Animals

Forty‐six dogs with AF and 24‐hour ambulatory recordings were evaluated.

Methods

Retrospective study. Holter‐derived HR variables were analyzed as follows: mean HR (meanHR, 24‐hour average), minimum HR (minHR, 1‐minute average), maximum HR (maxHR, 1‐minute average). Survival times were recorded from the time of presumed adequate rate control. The primary endpoint was all‐cause mortality. Cox proportional hazards analysis identified variables independently associated with survival; Kaplan‐Meier survival analysis estimated the median survival time of dogs with meanHR <125 bpm versus ≥125 bpm.

Results

All 46 dogs had structural heart disease; 31 of 46 had congestive heart failure (CHF), 44 of 46 received antiarrhythmic drugs. Of 15 dogs with cardiac death, 14 had CHF. Median time to all‐cause death was 524 days (Interquartile range (IQR), 76–1,037 days). MeanHR was 125 bpm (range, 62–203 bpm), minHR was 82 bpm (range, 37–163 bpm), maxHR was 217 bpm (range, 126–307 bpm). These were significantly correlated with all‐cause and cardiac‐related mortality. For every 10 bpm increase in meanHR, the risk of all‐cause mortality increased by 35% (hazard ratio, 1.35; 95% CI, 1.17–1.55; P < 0.001). Median survival time of dogs with meanHR<125 bpm (n = 23) was significantly longer (1,037 days; range, 524‐open) than meanHR ≥125 bpm (n = 23; 105 days; range, 67–267 days; P = 0.0012). Mean HR was independently associated with all‐cause and cardiovascular mortality (P < 0.003).

Conclusions and Clinical Importance

Holter‐derived meanHR affects survival in dogs with AF. Dogs with meanHR <125 bpm lived longer than those with meanHR ≥ 125 bpm.  相似文献   

Bahiagrass crop coefficients from eddy correlation measurements in central Florida     

Xinhua Jia  Michael D. Dukes  Jennifer M. Jacobs 《Irrigation Science》2009,28(1):5-15

Bahiagrass (Paspalum notatum) is a warm-season grass used primarily in pastures and along highways and other low maintenance public areas in Florida. It is also used in landscapes to some extent because of its drought tolerance. Bahiagrass can survive under a range of moisture conditions from no irrigation to very wet conditions. Its well-watered consumptive use has not been reported previously. In this study, bahiagrass crop coefficients (K _c) for an irrigated pasture were determined for July 2003 through December 2006 in central Florida. The eddy correlation method was used to estimate crop evapotranspiration (ET_c) rates. The standardized reference evapotranspiration (ET_o) equation (ASCE-EWRI standardization of reference evapotranspiration task committee report, 2005) was applied to calculate ET_o values using on site weather data. Daily K _c values were estimated from the ratio of the measured ET_c and the calculated ET_o. The recommended K _c values for bahiagrass are 0.35 for January–February, 0.55 for March, 0.80 for April, 0.90 for May, 0.75 for June, 0.70 for July–August, 0.75 for September, 0.70 for October, 0.60 for November, and 0.45 for December in central Florida. The highest K _c value of 0.9 in May corresponded with maximum vapor pressure deficit conditions as well as cloud free conditions and the highest incoming solar radiation as compared to the rest of the year. During the summer (June to August), frequent precipitation events increased the cloud cover and reduced grass water use. The K _c annual trend was similar to estimated K _c values from another well-watered warm-season grass study in Florida.  相似文献   

Are landscapes over-irrigated in Southwest Florida? A spatial�Ctemporal analysis of observed data     

Consuelo C. Romero  Michael D. Dukes 《Irrigation Science》2011,29(5):391-401

Monthly water billing records for eleven cities in Hillsborough County Florida were available from 2001 through 2007. Irrigation was estimated from total water use based on two different methods to estimate basic indoor water use and assumed impervious areas. Estimated irrigation use was compared with a calculated irrigation requirement by a water balance to test if homeowners were over-irrigating. Results showed that on average, the mean estimated irrigation was lower than the calculated irrigation requirements in most of the cities and years given the uncertainties in this analysis. The calculated irrigation ranged from 612 to 744 mm year⁻¹, whereas the average estimated irrigation ranged from 264 to 684 mm year⁻¹. However, there were some homeowners that greatly exceeded the calculated irrigation requirement. The estimated irrigation increased temporarily in areas under urban development, which was evidenced by built landscape expansion. Good correlation was found between the annual estimated irrigation and the annual calculated irrigation requirements, when the per capita method was used, but not between the annual estimated irrigation and the annual rainfall. Future conservation programs can use this methodology to identify users where substantial opportunity for water savings exists.  相似文献   

Landscape irrigation scheduling efficiency and adequacy by various control technologies   总被引：1，自引：0，他引：1  

M.S. McCreadyM.D. Dukes 《Agricultural Water Management》2011,98(4):697-704

Automated residential irrigation systems tend to result in higher water use than non-automated systems. Increasing the scheduling efficiency of an automated irrigation system provides the opportunity to conserve water resources while maintaining good landscape quality. Control technologies available for reducing over-irrigation include evapotranspiration (ET) based controllers, soil moisture sensor (SMS) controllers, and rain sensors (RS). The purpose of this research was to evaluate the capability of these control technologies to schedule irrigation compared to a soil water balance model based on the Irrigation Association (IA) Smart Water Application Technologies (SWAT) testing protocol. Irrigation adequacy and scheduling efficiency were calculated in 30-day running totals to determine the amount of over- or under-irrigation for each control technology based on the IA SWAT testing protocol. A time-based treatment with irrigation 2 days/week and no rain sensor (NRS) was established as a comparison. In general, the irrigation adequacy ratings (measure of under-irrigation) for the treatments were higher during the fall months of testing than the spring months due to lower ET resulting in lower irrigation demand. Scheduling efficiency values (measure of over-irrigation) decreased for all treatments when rainfall increased. During the rainy period of this testing, total rainfall was almost double reference evapotranspiration (ET_o) while in the remaining three testing periods the opposite was true. The 30-day irrigation adequacy values, considering all treatments, varied during the testing periods by 0-68 percentile points. Looking at only one 30-day testing period, as is done in the IA SWAT testing protocol, will not fully capture the performance of an irrigation controller. Scheduling efficiency alone was not a good indicator of controller performance. The amount of water applied and the timing of application were both important to maintaining acceptable turfgrass quality and receiving good irrigation adequacy and scheduling efficiency scores.  相似文献   

Avian ocular neoplasia--a description of spontaneously occurring cases.          下载免费PDF全文

T W Dukes  J R Pettit 《Canadian journal of veterinary research》1983,47(1):33-36

Twenty-one cases of ocular neoplasia were studied in birds submitted for diagnosis. Eighteen of these were lymphocytic tumors in chickens affecting various parts of the globe and retrobulbar tissues. Two cases of rhabdomyosarcoma in chickens were recorded. One of these was located in the anterior uvea and the other in the orbit. One adenocarcinoma was seen in a budgerigar.  相似文献   

The ocular lesions of naturally occurring lymphocystis in fish.          下载免费PDF全文

T W Dukes  A R Lawler 《Canadian journal of veterinary research》1975,39(4):406-410

Six cases of ocular lymphocystis, a virus disease, are described. Lymphocystis is generally known as a benigh, unique, giant cell disease of fishes causing nodules on the skin and fins. It has been studied extensively because of the virus-host cell relationship that results in extreme size and lack of quick cellular destruction or stimulation to neoplasia. Lymphocystis cells were found behind or in one or both eyes and were also found on the cornea or adjacent skin surfaces. A retrobulbar mass produced extreme exophthalmos. Uveal (choroid and iris) masses were present in most cases. Optic nerve involvement was also seen. It is probable that the virus reached the eye by the blood with the resulting masses forming in situ rather than by direct extension from skin lesions.  相似文献   

Atlas of Veterinary Opthalmoscopy          下载免费PDF全文

T. W. Dukes 《The Canadian veterinary journal. La revue veterinaire canadienne》1975,16(5):141

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Sporadic Bovine Leukosis: A Description of Eight Calves Received at Animal Diseases Research Institute from 1974-1980          下载免费PDF全文

A. Bundza  A.S. Greig  S. Chander  T.W. Dukes 《The Canadian veterinary journal. La revue veterinaire canadienne》1980,21(10):280-282,283

Eight calves with sporadic bovine leukosis are described. The common features were generalized lymphadenopathy, visceral involvement and raised total leukocyte and lymphocyte counts. Agar gel immunodiffusion tests for bovine leukemia virus antibodies were negative in eight animals and in all animals from three herds of origin. Lymphocytic nuclear pockets were found in the tissues of one calf but attempts to isolate bovine leukemia virus from two animals were unsuccessful.  相似文献   

Collection and analysis of exhaled breath condensate hydrogen peroxide in conscious healthy dogs     

Wyse CA  Hammond J  Arteaga A  Cumming D  Cooper JM  McEwan JD  Yam PS 《The Veterinary record》2004,155(23):744-746

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