Mastitis due to Mycoplasma in the state of New York during the period 1972-1990.

Between January 1972 and December 1990, bulk-tank (n = 721) and cow (n = 9,163) milk samples from dairy herds in New York State were examined by bacteriologic procedures for Mycoplasma. The organism was found in 165 herds in 42 counties, and in 2.3 and 11.7% of the tank and cow samples, respectively. Mycoplasma bovis was isolated in 164 herds, M. californicum was isolated in 1. Highest incidence of mycoplasmal clinical mastitis occurred during the winter. The disease resulted in culling of 30-70% of the cows in several herds. Eighty-six of the positive herds were located in the western part of the state. This area had more large herds (greater than 200 cows) compared to the rest of the state; however, herd size was not a risk factor. Purchased animals added to herds without quarantine, poor hygiene during mastitis treatment, and personnel in contact with mastitic cows or infected milk were involved in outbreaks and disease transmission.     

The confidential enquiry into perioperative equine fatalities (CEPEF): mortality results of Phases 1 and 2

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.     

Factors influencing female home range sizes in elk (<Emphasis Type="Italic">Cervus elaphus</Emphasis>) in North American landscapes

Home range size is a result of individual movements and the spatial distribution of a population. While body size, sex, and age are known to influence the area over which an animal ranges, it remains uncertain how landscape heterogeneity influences home range size. We examined elk (Cervus elaphus) seasonal home range sizes in relation to the quantity and spatial heterogeneity of forage biomass, forest cover, topography, snow–water equivalents, and landscape structure in three study landscapes: Yellowstone National Park, Wyoming, USA; eastern slopes of the Canadian Rockies, Alberta; and northern Wisconsin, USA. We used a 95% fixed kernel estimator to measure the home range size and location of all elk. To identify the scales at which important factors influenced home range sizes, we quantified environmental variables within the estimated home range polygon and within concentric circles with radii of 1000, 2000, 3000, 4000, and 5000 m from the home range center. Results indicate that there was an inverse relationship between forage biomass and summer and winter home range sizes in Alberta and Wisconsin, however the relationship was positive in Yellowstone. The size of summer and winter home ranges was positively related to percent forest cover; however this relationship was significant only when forest cover was quantified within the home range polygon or radii that were greater than or equal to 3000 m. Winter home ranges also had a positive relationship with snow–water equivalents. The predictive strength of summer home range models was greatest when landscape variables were quantified within the concentric circles with a radius of 3000 m or more, whereas the predictive strength of the winter models was greatest within the estimated home range polygon. Results suggest that elk ranging patterns reflected complex trade-offs that affect foraging, group dynamics, movement energetics, predation avoidance and thermal regulation. The multi-scale analysis indicates that elk based home ranging decisions on an area equal to their home range, but areas outside of the estimated home range were also important.     

Radar detection of the nucleus and coma of comet hyakutake

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.     

Comparison of techniques for quantifying alkaline phosphatase isoenzymes in canine serum

Three methods for quantifying the steroid-induced and liver isoenzymes of alkaline phosphatase in canine serum were compared on a group of 29 canine serum samples with increased total alkaline phosphatase activity. Levamisole inhibition, heat inactivation, and affinity electrophoresis with densitometry yielded results that correlated strongly. The relationship between levamisole inhibition and heat inactivation test values was a simple linear one, whereas the relationship between their values and those of electrophoresis was better fitted to an exponential model. The levamisole inhibition and heat inactivation tests provided essentially the same information regarding the relative proportions of steroid-induced and hepatic isoenzymes in canine serum; either test was judged practical for routine clinical application.     

Grassland vegetation changes and nocturnal global warming

Global minimum temperatures (TMIN) are increasing faster than maximum temperatures, but the ecological consequences of this are largely unexplored. Long-term data sets from the shortgrass steppe were used to identify correlations between TMIN and several vegetation variables. This ecosystem is potentially sensitive to increases in TMIN. Most notably, increased spring TMIN was correlated with decreased net primary production by the dominant C4 grass (Bouteloua gracilis) and with increased abundance and production by exotic and native C3 forbs. Reductions in B. gracilis may make this system more vulnerable to invasion by exotic species and less tolerant of drought and grazing.     

Leaching requirement for salinity control I. Wheat,sorghum, and lettuce

Crop productivity and water use efficiency when saline irrigation water is used are highest when efficient irrigation systems are managed to meet the crop's leaching requirement. The objective of this experiment was to establish the leaching requirement. The objective of this experiment was to establish the leaching requirements for frequently irrigated wheat, grain sorghum, and head lettuce. The 4-year study in field plots consisted of six replicated leaching fraction treatments. The plots were pulse-irrigated daily with water having a total dissolved salts concentration of 1350 mg/l.The leaching requirements are 0.08 for wheat and sorghum, and 0.26 for lettuce. The respective evapotranspiration during each crop's growing season coincident with the leaching requirements was 440, 550, and 245 mm. A pan factor of 0.7 was consistent among these three crops at their respective leaching requirements. With daily irrigation, 90% of the crop's water uptake occurred above a soil depth of 0.6 m, independent of leaching fraction.