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At least 325 records · Page 18Linked to original sources
PubMed1989

On the release of asbestos fibers from weathered and corroded asbestos cement products.

The controversy on whether weathered and corroded asbestos cement products are emitting biologically significant asbestos fiber concentrations in ambient air has not been resolved. Nor is it known if the weathered and corroded asbestos cement products release asbestos fibers which have the same carcinogenic potency as "standard" chrysotile. The purpose of this research project was to develop a method for sampling and measuring asbestos fiber emissions from solid planar surfaces (i.e., roofs and facades) consisting of asbestos cement products and to develop methods for studying the physical and chemical changes and the carcinogenic potency of the emitted fibers. Using this method asbestos fiber emissions in ambient air have been measured in the FRG during 1984/1986. The emissions of asbestos fibers longer than 5 microns were in the range 10(6) to 10(8) fibers/m2.hr. The ambient air concentrations of these asbestos fibers were for the most part less than 10(3) fibers/m3. It was shown that the emitted asbestos fibers were chemically changed and it was shown with animal experiments that their carcinogenic potency did not differ from the carcinogenicity of "standard" chrysotile fibers.

Air Pollutants↗
PubMed1996

Effects of the weather conditions on mood and behaviour: the role of acupuncture points.

The proposed hypothesis is that the effects of changing weather patterns on mood and behaviour are mediated by electrical processes in acupuncture points. Atmospheric electricity affects the state of acupuncture points. This change causes alterations in the functioning of neurotransmitters in the central nervous system, which leads to a shift in the psychological condition. Electroacupuncture can be a means to treat, or to prevent the negative influences of unsettling weather conditions.

Acupuncture Points↗
PubMed1999

Scaling in nature: from DNA through heartbeats to weather.

The purpose of this report is to describe some recent progress in applying scaling concepts to various systems in nature. We review several systems characterized by scaling laws such as DNA sequences, heartbeat rates and weather variations. We discuss the finding that the exponent alpha quantifying the scaling in DNA in smaller for coding than for noncoding sequences. We also discuss the application of fractal scaling analysis to the dynamics of heartbeat regulation, and report the recent finding that the scaling exponent alpha is smaller during sleep periods compared to wake periods. We also discuss the recent findings that suggest a universal scaling exponent characterizing the weather fluctuations.

Algorithms↗
PubMed2003

Effect of controlled-release melatonin on sleep quality, mood, and quality of life in subjects with seasonal or weather-associated changes in mood and behaviour.

This study aimed to explore the effects of melatonin on sleep, waking up and well being in subjects with varying degrees of seasonal or weather-associated changes in mood and behaviour. Fifty-eight healthy adults exhibiting subsyndromal seasonal affective disorder (s-SAD) and/or the negative or positive type of weather-associated syndrome (WAS) were randomised to either 2 mg of sustained-release melatonin or placebo tablets 1-2 h before a desired bedtime for 3 weeks. Outcome measures were changes from baseline in sleep quality, sleepiness after waking, atypical depressive symptoms and health-related quality of life by week three. Early morning salivary melatonin concentrations were measured at baseline and treatment cessation in all subjects. Melatonin administration significantly improved the quality of sleep (P=0.03) and vitality (P=0.02) in the subjects with s-SAD, but attenuated the improvement of atypical symptoms and physical parameters of quality of life compared to placebo in the subjects with WAS, positive type.

Adult↗
PubMed1993

Weather factors in the prediction of western equine encephalitis epidemics in Manitoba.

Cases of western equine encephalitis in horses in 1987 in western USA and Manitoba, Canada were examined by backward trajectory analysis of winds. Culex tarsalis mosquitoes infected with western equine encephalitis virus could have been carried on southerly winds from Texas and Oklahoma to northern USA and from there to Manitoba. The presence of the Polar front over North Dakota and Minnesota at the end of July would have led to the landing of Cx. tarsalis in Montana and Wisconsin and prevented further carriage into Manitoba. Temperatures in southern Texas during the winter months (average daily maximum temperatures 19.7 degrees C and higher) would have permitted continuous transmission of western equine encephalitis virus by Cx. tarsalis in this area. Weather factors involved in outbreaks from 1975-88 were analysed to see if epidemics in Manitoba (23 or more cases in horses) could be predicted. The conditions for epidemics could be defined as follows: (a) the number of cases in horses in USA was 98 or more, (b) winds were southerly with speeds 45 kmh-1 or higher, and (c) counts of Cx. tarsalis females/light trap per day were 3.2 or higher. There were 3 or fewer cases in Manitoba, when the number of cases in USA was 27 or less, even when Cx. tarsalis counts were higher than 3.2. With Cx. tarsalis counts below 3 and/or unsuitable winds, or the Polar front further south, the number of cases in Manitoba was between 0 and 17, even when the number of cases in USA was from 38-172. Without information on the extent of infection further south, the weather variables would probably be more useful in excluding the possibility of an epidemic in Manitoba than in predicting one.

Animals↗
PubMed2001

Standardisation of temperature observed by automatic weather stations.

Daily mean, maximum and minimum surface air temperature data were gathered from a network of automatic weather stations (AWS) within the Moor House National Nature Reserve in northern England. Five AWS were installed next to the official Environmental Change Network weather station at Moor House. Data were compared graphically and correction constants were calculated to adjust data from each AWS to the standard of the official station by optimising the concordance correlation coefficient. Each corrected station was re-located next to one of five in-situ stations in and around the reserve, allowing correction of all temperature sensors to a common standard. The mean error associated with measured daily mean, maximum and minimum temperature for each sensor does not exceed +/- 0.2 K. The procedure quantifies a source of systematic measurement error, improving the identification of spatial temperature differences between stations.

Air↗
PubMed1997

Seasonal variation and weather effects on road traffic accidents in Riyadh city.

The monthly variation of Road Traffic Accidents (RTAs) in Riyadh city in the period 1989-1993 has been studied with reference to time of day, lighting conditions and prevalent weather conditions. Total RTA accidents were significantly more common, being directly correlated, with increased dry and wet bulb temperatures and significantly less common, being inversely correlated, with increased relative humidity and amount of precipitation of rain, snow, hail etc. However, RTAs recorded on rainy days only were significantly more common and directly correlated with precipitation (Note days of snow and hail are very rare in Riyadh city). Seasonal variation in RTAs was evident being maximal during the summer season particularly between 12 noon and 3 pm. This period is characterized by heavy traffic and intense sunlight. The role of hot weather prevalent in Saudi Arabia, where average temperatures of 34.4-34.7 degrees C with maximum of 40-42.7 degrees C are common in summer, have been suggested to be an important factor leading to increased stress and decreased performance of intellectual tasks which require considerable physical effort and motor skills. Increased heart rates, exacerbation of existing pathologic conditions such as heart disease and emphysema and loss of visual acuity have been reported. Consequently, prolonged exposure to heat must be considered as a hazard to the safety and health of drivers and a factor leading to an increased incidence of RTAs.

Accidents, Traffic↗
PubMed1996

[Effect of weather on the incidence of sudden deafness].

BACKGROUND: The etiology of sudden idiopathic hearing loss is not known. Among other causes, vascular disease is discussed as a possible pathomechanism in sudden hearing loss. Since other vascular diseases such as myocardial infarction, migraine, and open-angle glaucoma show a clear meteorotropy, it was the aim of the present prospective study to investigate the dependence of sudden hearing loss on weather parameters. PATIENTS AND METHODS: The incidence, the extent, and the remission of sudden idiopathic hearing loss in 128 patients were correlated with atmospheric pressure and temperature during a period of 12 months. RESULTS: The group of patients with a complete recovery of hearing thresholds was characterized by the smallest changes of atmospheric pressure and temperature, whereas patients with no recovery of hearing had the highest values for atmospheric pressure and temperature changes. However, a statistically significant correlation of sudden hearing loss with absolute values or relative changes of atmospheric air pressure or temperature was not found. Likewise, there was no seasonal dependence. CONCLUSION: The results indicate that sudden idiopathic hearing loss occurs independently of weather parameters.

Adolescent↗
PubMed1986

[Weather influences on intraocular pressure in patients with chronic glaucoma or ocular hypertension].

From January 1979 to August 1984 intraocular pressure (IOP) was measured on the first Friday of each month under comparable conditions (same instruments, nearly always the same examiner) in a total of 109 patients in whom a primary chronic open-angle glaucoma or ocular hypertension had been diagnosed: The IOP was correlated to the local weather parameters (atmospheric pressure, cloud cover, relative air humidity, mean, maximum and minimum temperature, precipitation, duration of sunshine, mean and maximum wind velocity). In the large number of measurements a significant correlation was found only between IOP and atmospheric pressure: IOP was lower when air pressure was high. There was only a suggestion of a significant correlation between IOP and relative air humidity. However, further statistical analysis revealed that in fact both atmospheric pressure and relative air humidity account for only a negligible part of the variation in IOP values. From a practical point of view, therefore, the IOP of patients with primary chronic open-angle glaucoma or ocular hypertension is not influenced by weather conditions.

Atmospheric Pressure↗
PubMed2005

Synoptic weather patterns and modification of the association between air pollution and human mortality.

To assess whether meteorological conditions modify the relationship between short-term exposure to ambient air pollution and mortality, an examination of air pollution and human mortality associations (ecologic) using hybrid spatial synoptic classification procedures was conducted. Concentrations of air pollutants and human mortality from all non-accidental and cardiorespiratory causes were examined according to typical winter and summer synoptic climatologies in Toronto, Canada, between 1981 and 1999. Air masses were derived using a hybrid spatial synoptic classification procedure associating each day over the 19-year period with one of six different typical weather types, or a transition between two weather types. Generalized linear models (GLMs) were used to assess the risk of mortality from air pollution within specific air mass type subsets. Mortality follows a distinct seasonal pattern with a maximum in winter and a minimum in summer. Average air pollution concentrations were similar in both seasons with the exception of elevated sulfur dioxide levels in winter and elevated ozone levels in summer. Subtle changes in meteorological composition can alter the strength of pollutant associations with health outcomes, especially in the summer season. Although there does not appear to be any systematic patterning of modification, variation in pollutant concentrations seems dependent on the type of synoptic category present.

Air Pollutants↗
PubMed1998

Failure to predict abundance of saltmarsh mosquitoes Aedes sollicitans and A. taeniorhynchus (Diptera: Culicidae) by using variables of tide and weather.

Weather and tide variables were used to develop regression models with light trap counts of Aedes sollicitans (Walker) and Aedes taeniorhynchus (Wiedemann) from 1984 to 1995. Rains, tides, and temperatures, both during and preceding the sample period, all showed significant correlations with trap counts. These multiple regression models forecasted general population levels during 1996 and 1997, but not the size of the peaks. Therefore, weather alone can predict general trends but cannot be used to accurately predict population levels of Ae. sollicitans and Ae. taenio-rhynchus.

Aedes↗
PubMed1992

Air-conditioning and mortality in hot weather.

A cohort of 72,740 persons for whom information on household air-conditioning was available was monitored for mortality via the National Death Index from April 1980 through December 1985. A total of 2,275 deaths occurred among the members of this cohort. The basic question addressed was whether persons in households with air-conditioning experienced lower death rates during hot weather than persons in households without air-conditioning. This question was examined for both central and room air-conditioning. The analysis was based on a state-by-state approach, that cross-tabulated deaths by air-conditioning status (yes or no) and average temperature during the month of death (less than 21.2 degrees C (less than 70 degrees F) or greater than or equal to 21.2 degrees C (greater than or equal to 70 degrees F)). The Mantel-Haenszel and sign tests were used to summarize the data. For central air-conditioning versus no air-conditioning, statistically significant benefits (p less than 0.05, Mantel-Haenszel test) were observed for the overall total, for females, for persons not in the labor force, and for persons living in fewer than six rooms. These groups had more exposure to air-conditioning. The relative risk for the total group was 0.58, implying that in hot weather, the death rate for persons who had central air-conditioning was 42 percent lower than the rate for persons who did not have air-conditioning, after confounding variables had been controlled for. For room air-conditioning versus no air-conditioning, the odds ratio for the total group was 0.96, which was not significantly different from 1.0, suggesting that no real benefit was derived from room air-conditioning. Some reasons for the lack of a demonstrable benefit for room air-conditioning are given.

Aged↗
PubMedDate not supplied

How do people solve the "weather prediction" task?: individual variability in strategies for probabilistic category learning.

Probabilistic category learning is often assumed to be an incrementally learned cognitive skill, dependent on nondeclarative memory systems. One paradigm in particular, the weather prediction task, has been used in over half a dozen neuropsychological and neuroimaging studies to date. Because of the growing interest in using this task and others like it as behavioral tools for studying the cognitive neuroscience of cognitive skill learning, it becomes especially important to understand how subjects solve this kind of task and whether all subjects learn it in the same way. We present here new experimental and theoretical analyses of the weather prediction task that indicate that there are at least three different strategies that describe how subjects learn this task. (1) An optimal multi-cue strategy, in which they respond to each pattern on the basis of associations of all four cues with each outcome; (2) a one-cue strategy, in which they respond on the basis of presence or absence of a single cue, disregarding all other cues; or (3) a singleton strategy, in which they learn only about the four patterns that have only one cue present and all others absent. This variability in how subjects approach this task may have important implications for interpreting how different brain regions are involved in probabilistic category learning.

Adult↗
PubMed1990

Epistaxis: a study of the relationship with weather.

Epistaxis is the commonest ENT emergency requiring hospital admission. A seasonal variation in the admission rate has been documented. The role of weather in accounting for this variation is uncertain. A retrospective review of 686 adult hospital admissions for idiopathic spontaneous epistaxis over a 2-year period in the Greater Glasgow area was carried out. The most significant weather parameter which correlated with monthly admissions was mean monthly temperature (Pearson's correlation coefficient -0.81, P less than 0.01). Admissions increased by over 100% from the warmest to the coldest months. This is the first report of the high correlation between hospital admissions for epistaxis and mean monthly temperature.

Adolescent↗
PubMed2000

Disaster management. U.S. policies pertaining to weather and climate extremes.

Climate and weather extremes--floods, drought, storms, severe weather--now have an impact on all levels of government and on the insurance industry. U.S. national policy has moved from structural approaches (building dams, levees, and irrigation ditches) to societal approaches: moving people out of hazardous areas, seeking improvements in building codes, and encouraging the use of crop and flood insurance. Federal relief assistance policies have been called into question, and renewed emphasis on personal responsibility is part of future policy.

Climate↗
PubMed2000

The effects of changing weather on public health.

Many diseases are influenced by weather conditions or display strong seasonality, suggestive of a possible climatic contribution. Projections of future climate change have, therefore, compelled health scientists to re-examine weather/disease relationships. There are three projected physical consequences of climate change: temperature rise, sea level rise, and extremes in the hydrologic cycle. This century, the Earth has warmed by about 0.5 degrees centigrade, and the mid-range estimates of future temperature change and sea level rise are 2.0 degrees centigrade and 49 centimeters, respectively, by the year 2100. Extreme weather variability associated with climate change may especially add an important new stress to developing nations that are already vulnerable as a result of environmental degradation, resource depletion, overpopulation, or location (e.g. low-lying coastal deltas). The regional impacts of climate change will vary widely depending on existing population vulnerability. Health outcomes of climate change can be grouped into those of: (a) direct physical consequences, e.g. heat mortality or drowning; (b) physical/chemical sequelae, e.g. atmospheric transport and formation of air pollutants; (c) physical/biological consequences, e.g. response of vector- and waterborne diseases, and food production; and (d) sociodemographic impacts, e.g. climate or environmentally induced migration or population dislocation. Better understanding of the linkages between climate variability as a determinant of disease will be important, among other key factors, in constructing predictive models to guide public health prevention.

Communicable Diseases↗
PubMed2001

Association between weather conditions and the incidence of emergency gynecological consultations.

OBJECTIVE: This study examined the influence of weather conditions on the incidence of outpatient emergency consultations at the Department of Obstetrics and Gynecology at the Regional Hospital in Lugano, Switzerland. STUDY DESIGN: The medical records of all women who attended the outpatient emergency unit at the Department for Obstetrics and Gynecology over the 1-year study period were reviewed. The final diagnosis was pelvic pain of unidentified origin in 180 cases, menorrhagia and/or metrorrhagia in 95 cases, threatened abortion in 56 cases and spontaneous abortion in 54 cases. The meteorological factors considered were atmospheric pressure, temperature, humidity and global radiation. A logistic regression model was used to correlate the occurrence of symptoms with the chosen weather factors. RESULTS: High mean daily temperature was found to be a significant predictor of pelvic pain (p < 0.001). A rise in barometric pressure compared to the previous day increased the probability of menorrhagia and/or metrorrhagia (p = 0.001). Higher minimal temperature (p = 0.011) and an increase in atmospheric pressure (p = 0.006) were identified as positive predictors of threatened abortion. None of the meteorological factors considered seemed to influence the frequency of spontaneous abortions. CONCLUSION: Meteorological factors such as temperature and barometric change appear to affect the probability of emergency admissions for gynecological symptoms including uterine bleeding, threatened abortion and pelvic pain.

Abortion, Spontaneous↗
PubMedDate not supplied

The unfortunate influence of the weather on the rate of ageing: why human caloric restriction or its emulation may only extend life expectancy by 2-3 years.

Much research interest, and recently even commercial interest, has been predicated on the assumption that reasonably closely-related species--humans and mice, for example--should, in principle, respond to ageing-retarding interventions with an increase in maximum lifespan roughly proportional to their control lifespan (that without the intervention). Here, it is argued that the best-studied life-extending manipulations of mice are examples of a category that is highly unlikely to follow this rule, and more likely to exhibit only a similar absolute increase in maximum lifespan from one species to the next, independent of the species' control lifespan. That category--reduction in dietary calories or in the organism's ability to metabolize or sense them--is widely recognized to extend lifespan as an evolutionary adaptation to transient starvation in the wild, a situation which alters the organism's optimal partitioning of resources between maintenance and reproduction. What has been generally overlooked is that the extent of the evolutionary pressure to maintain adaptability to a given duration of starvation varies with the frequency of that duration, something which is--certainly for terrestrial animals and less directly for others--determined principally by the weather. The pattern of starvation that the weather imposes is suggested here to be of a sort that will tend to cause all terrestrial animals, even those as far apart phylogenetically as nematodes and mice, to possess the ability to live a similar maximum absolute (rather than proportional) amount longer when food is short than when it is plentiful. This generalization is strikingly in line with available data, leading (given the increasing implausibility of further extending human mean but not maximum lifespan in the industrialized world) to the biomedically and commercially sobering conclusion that interventions which manipulate caloric intake or its sensing are unlikely ever to confer more than 2 or 3 years' increase in human mean or maximum lifespan at the most.

Aging↗