International journal of biometeorology
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Randomized Controlled Trial
Effect of sprinkling on feedlot microclimate and cattle behavior.
Experiments were conducted to evaluate strategies designed to reduce heat stress of cattle. In the first experiment, cattle were sprinkled for 20 min every 1.5 h between 1000 hours and 1750 hours (WET) versus not sprinkled (DRY). In a second experiment, treatments consisted of: (1) control, no water application; (2) water applied to the pen surfaces between 1000 hours and 1200 hours (AM); and (3) water applied to pen surfaces between 1400 hours and 1600 hours (PM). ⋯ Pens with sprinklers had a larger percentage of steers in areas where sprinkling took place, even on days when sprinkling had not occurred. Based on differences in percentage of cattle panting in sprinkled and non-sprinkled treatments, sprinkling was found to have a positive effect on cattle feeding area microclimate and to reduce the susceptibility of cattle to hyperthermia. However, cattle acclimatization to being sprinkled can result in slight hyperthermia even during cooler days when sprinkling would normally not be utilized.
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This paper takes an air mass approach to investigating the influence of weather on pollen concentrations in the atmosphere in Sydney, Australia, by producing a synoptic classification of pollen concentrations measured in the Sydney Basin. This synoptic classification has been produced using multivariate statistical techniques including principal component analysis and cluster analysis, to assign days into meteorologically homogenous categories. Surface and upper air meteorological data for warm months (October-March) over a 10-year period were used as input into the statistical analyses. ⋯ Pollen concentrations for the total pollen load and five individual families measured over a 3.5-year period have been investigated for each of the synoptic categories. High pollen concentrations during the warm months in Sydney are found to be influenced by the presence of a region of low surface pressure located to the south of the continent, bringing fast dry westerly gradient winds to Sydney. It is envisaged that these results will be important from a pollen forecast and associated public health perspective.
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As the numbers of middle-aged and elderly mountain climbers have increased with the general aging of the population, accidents during mountain climbing have increased recently. A possible cause of such accidents is an excessively difficult expedition plan. To enjoy safe mountain climbing, the plans must take account of the climber's fitness level. ⋯ Therefore, if the CHI value of an individual is known (it can be estimated from. VO(2 max)), safer mountain climbing can be planned accordingly. Once determined, this CHI value can be used repeatedly unless the fitness level of the individual changes.
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The occurrence of pollen grains in the atmosphere markedly relates to meteorological factors. In the study we have evaluated a correlation between the concentration of pollen grains in the atmosphere of Bratislava and temperature, relative humidity and rainfall during the vegetation period of 1995 and 1997. For our analysis we have selected one representative of each phytoallergen group (trees, grasses, weeds). ⋯ The correlation between the concentration of pollen grains in the atmosphere and selected meteorological variables from daily monitoring has been studied with the help of linear regression and correlation coefficients. We have found the average daily temperature and relative humidity (less than temperature) to be significant factors influencing the occurrence of pollen grains in the atmosphere of Bratislava. The total daily rainfall does not seem to be significant from the statistical point of view.
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An integration-type laser-Doppler flowmeter, equipped with a temperature-load instrument, for measuring skin blood flow (ILD-T), and analytical parameters developed in a previous study were used to compare changes in the skin blood flow in the forehead and cheek in elderly subjects (in their 60s and 70s) with those in younger subjects (in their teens to 50s). Age-related differences in skin blood flow in the forehead and cheek in response to cooling were evaluated in 90 healthy women in their teens to 70s (mean age: 17.2 +/- 0.33 years for teenagers; 24.3 +/- 0.76 years for those aged 20-29 years; 34.8 +/- 1.12 years for those aged 30-39 years; 43.3 +/- 0.78 years for those aged 40-49 years; 53.8 +/- 1.13 years for those aged 50-59 years; 63.5 +/- 0.55 years for those aged 60-69 years; 72.2 +/- 0.70 years for those aged 70-79 years). The measurement was performed continuously for 5 min: for 1 min at a sensor temperature of 30 degrees C, for 2 min after the setting of the sensor temperature had been changed to 10 degrees C, and for 2 min after the temperature setting had been cancelled. ⋯ In the cheek, on the other hand, the skin blood flow decreased markedly with aging, but no clear change was observed in the rate of this decrease. By using ILD-T and examining various parameters obtained, the skin hemodynamics in the forehead and cheek during cooling from 30 degrees C to 10 degrees C could be analyzed, and differences in the hemodynamics between the forehead and cheek and between elderly and younger individuals were clarified. This instrument is expected to be clinically useful.