Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Weather”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources
PubMed1984

Influence of weather on reproduction.

Laboratory investigations suggest that the effects of weather on avian reproduction could be manifest via a "stress" response resulting in an elevation of circulating levels of corticosterone and a depression of reproductive hormone secretion. However, field investigations indicate that additional endocrine responses also occur. Inclement weather early in the breeding season, i.e., before the nesting phase has begun, is generally not stressful in terms of plasma levels of corticosterone but does result in a delay of gonadal maturation and decreases in circulating levels of LH and sex steroid hormones. Conversely, storms that strike after the nesting phase has begun and when adults are feeding young do appear to be stressful, resulting in an increase in corticosterone and loss of body weight, but do not affect plasma levels of LH and sex steroid hormones. This latter fact is thought to be highly adaptive because the reproductive apparatus is maintained in a functional state so that renesting can begin immediately when environmental conditions improve. These data indicate that two endocrine mechanisms may be important for regulating responses to inclement weather under natural conditions.

Animals↗
PubMed1991

Weather fronts and acute myocardial infarction.

Some methodological aspects are discussed of the investigation of acute infarct myocarditis (AIM) in relation to weather fronts. Results of a new method of analysis are given. Data were analysed from about the hour of the onset of symptoms, and led to the diagnosis of AIM either immediately or within a few hours or days (3019 cases observed over 4.5 years during 1982-1986 in Plzen, Czechoslovakia). Weather classification was based on three factors (the type of the foregoing front, the type of the subsequent front, the time section of the time interval demarcated by the passage of the surfaces of the fronts). AIM occurrence increased in particular types of weather fronts: (i) by 30% during 7-12 h after a warm front, if the time span between fronts exceeded 24 h; (ii) by 10% in time at least 36 h distant from the foregoing cold or occlusion front and from the succeeding warm or occlusion front; (iii) by 20% during 0-2 h before the passage of the front, provided the foregoing front was not warm and the interval between fronts exceeded 5 h. AIM occurrence decreased by 15%-20% for time span between fronts greater than 24 h at times 6-11, 6-23 and 6-35 h before a coming warm or occlusion front (for interfrontal intervals 25-48, 49-72 and possibly greater than 72 h), and also at 12-23 and possibly 12-35 h before a cold front (for intervals 49-72 and possibly greater than 72 h), if the foregoing front was cold or an occlusion front.

Czechoslovakia↗
PubMed1995

Weather and childbirth: a further search for relationships.

Previous attempts to find relationships between weather and parturition (childbirth) and its onset (the beginning of labor pains) have revealed, firstly, limited but statistically significant relationships between weather conditions much colder than the day before, with high winds and low pressure, and increased onsets; and secondly, increased numbers of childbirths during periods of atmospheric pressure rise (highly statistically significant). To test these findings, this study examined weather data coincident childbirth data from a hospital at Bryan-College Station, Texas (for a period of 30 cool months from 1987 to 1992). Tests for (1) days of cold fronts, (2) a day before and a day after the cold front, (3) days with large temperature increases, and (4) decreases from the day before revealed no relationship with mean daily rate of onset. Cold days with high winds and low pressure had significantly fewer onsets, a result that is the opposite of previous findings. The postulated relationship between periods of pressure rise and increased birth frequency was negative, i.e., significantly fewer births occurred at those times--again, the opposite of the apparent occurrence in an earlier study. The coincidence of diurnal variations in both atmospheric pressure and frequency of childbirths, was shown to account for fairly strong negative associations between the two variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Atmospheric Pressure↗
PubMed1992

Study of the relationships between weather conditions and the marathon race, and of meteorotropic effects on distance runners.

The relationships between the results of Beijing International Marathon Races and the corresponding weather conditions are analysed quantitatively. There are obvious interrelationships between the marathon results and weather factors such as air temperature, wet bulb temperature and human biometeorological indices. For example, the correlation coefficient between the average times of the top ten finishers and temperature is r = 0.8910. The meteorological conditions are classified into three categories, suitable, moderate and unsuitable for running a marathon race, and the optimum meteorological index is given. Also the concept of a meteorological result, i.e. the part of the actual performances fluctuating with the changes in weather conditions, is presented. This plays an important role in some kinds of sports such as marathon racing. Finally, the results of physiological tests are given, which illustrate the physiological reactions of long- and middle-distance runners to the surrounding temperature.

Exercise↗
PubMed1996

Predicting daily visits to a walk-in clinic and emergency department using calendar and weather data.

We studied the association between calendar and weather variables and daily unscheduled patient volume in a walk-in clinic and emergency department. Calendar variables (season, week of month, day of week, holidays, and federal check-delivery days) and weather variables (high temperature and snowfall) forecasted clinic volume, explaining 84% of daily variance and 44% of weekday variance. Staffing according to predicted volume could have decreased overstaffing from 59% to 15% of days, but would have increased understaffing from 2% to 18% of days. Models using calendar and weather data that forecast local utilization may help to schedule staffing for walk-in clinics and emergency departments more efficiently.

Emergency Service, Hospital↗
PubMed2005

Using satellite fire detection to calibrate components of the fire weather index system in Malaysia and Indonesia.

Vegetation fires have become an increasing problem in tropical environments as a consequence of socioeconomic pressures and subsequent land-use change. In response, fire management systems are being developed. This study set out to determine the relationships between two aspects of the fire problems in western Indonesia and Malaysia, and two components of the Canadian Forest Fire Weather Index System. The study resulted in a new method for calibrating components of fire danger rating systems based on satellite fire detection (hotspot) data. Once the climate was accounted for, a problematic number of fires were related to high levels of the Fine Fuel Moisture Code. The relationship between climate, Fine Fuel Moisture Code, and hotspot occurrence was used to calibrate Fire Occurrence Potential classes where low accounted for 3% of the fires from 1994 to 2000, moderate accounted for 25%, high 26%, and extreme 38%. Further problems arise when there are large clusters of fires burning that may consume valuable land or produce local smoke pollution. Once the climate was taken into account, the hotspot load (number and size of clusters of hotspots) was related to the Fire Weather Index. The relationship between climate, Fire Weather Index, and hotspot load was used to calibrate Fire Load Potential classes. Low Fire Load Potential conditions (75% of an average year) corresponded with 24% of the hotspot clusters, which had an average size of 30% of the largest cluster. In contrast, extreme Fire Load Potential conditions (1% of an average year) corresponded with 30% of the hotspot clusters, which had an average size of 58% of the maximum. Both Fire Occurrence Potential and Fire Load Potential calibrations were successfully validated with data from 2001. This study showed that when ground measurements are not available, fire statistics derived from satellite fire detection archives can be reliably used for calibration. More importantly, as a result of this work, Malaysia and Indonesia have two new sources of information to initiate fire prevention and suppression activities.

Calibration↗
PubMed2004

Weather variation and trophic interaction strength: sorting the signal from the noise.

Weather can have important consequences for the structure and function of ecological communities by substantially altering the nature and strength of species interactions. We examined the role of intra- and inter-annual weather variability on species interactions in a seasonal old-field community consisting of spider predators, grasshopper herbivores, and grass and herb plants. We experimentally varied the number of trophic levels for 2 consecutive years and tested for inter-annual variation in trophic abundances. Grasshopper emergence varied between years to the extent that the second growing season was 20% shorter than the first one. However, the damage grasshoppers inflicted on plants was greater in the second, shorter growing season. This inter-annual variation in plant abundance could be explained using the foraging-predation risk trade-off displayed by grasshoppers combined with their survival trajectory. Decreased grasshopper survival not only reduced the damage inflicted on plants, it weakened the strength of indirect effects of spiders on grass and herb plants. The most influential abiotic factor affecting grasshopper survival was precipitation. We found a negative association between grasshopper survival and the total yearly precipitation. A finer scale analysis, however, showed that different precipitation modalities, namely, number of rainy days and average precipitation per day, had opposing effects on grasshopper survival, which were inconsistent between years. Furthermore, our results suggest that small changes in these factors should result in changes of up to several orders of magnitude in the mortality rate of grasshoppers. We thus conclude that in this system the foraging-predation risk trade-off displayed by grasshoppers combined with their survival trajectory and relevant weather variability should be incorporated in analytical theory, whose goal is to predict community dynamics.

Animals↗
PubMed2004

Over-winter survival in subadult European rabbits: weather effects, density dependence, and the impact of individual characteristics.

The survival probability of an individual may be limited by density-dependent mechanisms and by environmental stochasticity, but can also be modified by individual characteristics. In our study, we investigated over-winter survival of subadults of an enclosed European rabbit Oryctolagus cuniculus population in a temperate zone habitat over the period 1992-2002. We: (1) selected for appropriate models to explain individual variation in over-winter survival and the animals' autumn body mass, the latter was used as a measure of the individual pre-winter body condition; and (2) aimed to compare the sensitivity of the target variables on the realised variation of the factors considered. Model selection based on information theory revealed that individual over-winter survival was best explained by the combination of autumn body mass, winter temperature, population density and sex, where the probability of survival was higher in females than in males. According to this model, the probability of survival reacted most sensitively to variation in the autumn body mass and in winter temperature. Individual autumn body mass was best explained by the combination of the date of birth, population density, and weather conditions by means of the percentage of rainy days during the first 2 months after the animals had emerged above ground, where the autumn body mass was negatively related to the percentage of rainy days. The chosen model suggested that the autumn body mass reacted most sensitively to variation in the date of birth. Combining these models, we found that weather conditions during two different periods of time as well as population density, sex and the date of birth operated together to determine the probability of over-winter survival. In particular, the study points out the high impact of environmental stochasticity on over-winter survival: (1) by direct effects of winter temperature conditions, and (2) by the indirect action of weather conditions to which the animals were exposed during the early period of juvenile development.

Age Factors↗
PubMed2005

The influences of weather on patients with different ovarian responses in the treatment of assisted reproductive technology.

PURPOSE: The purpose of this study was to evaluate the influences of tropical weather on patients with different ovarian responses in the treatment of assisted reproductive technology. METHODS: Six-hundred fourty-seven women underwent their first treatment cycles were retrospectively analyzed. Patients received embryo transfer either 3 days or 5 days after oocyte retrieval, depending on the number and quality of embryos on day-2. RESULTS: Significant correlations were demonstrated in the top quality embryo rates of day-3 and day-5 embryo transfers with temperature, humidity, and atmosphere pressure. The cumulative light hours negatively correlated with the implantation and pregnancy rates of day-3 embryo transfer (-.282 and -.282, respectively), while they positively correlated with those of day-5 embryo transfer (.225 and .224, respectively). CONCLUSIONS: These results clearly suggest that weather may exert influences on the outcome of assisted reproductive technology. Patients with different ovarian responses or blastocyst culture and transfer may modify weather influences.

Adult↗
PubMed1994

REE chemistry and Sm-Nd systematics of late Archean weathering profiles in the Fortescue Group, Western Australia.

Two weathering profiles, each consisting of an upper, sericite-rich zone and a lower, chlorite-rich zone, are preserved between flows of the Mt. Roe Basalt in the Fortescue Group, Hamersley Basin, Western Australia. REE concentrations in samples from these two profiles, which originally developed ca 2,760 Ma, show large variations depending on stratigraphic position. LREE abundances and (La/Yb)N are greatest at depths of 3-6 m below the paleosurface of the Mt. Roe #1 profile and are somewhat lower in samples above this level. The LREEs reach concentrations 6-9 times greater than in the underlying basalt, and thus appear to have been mobilized downward in the paleosol and concentrated in its middle part. LREE concentrations in the #2 profile show a similar distribution but with a sharp increase in all REE concentrations within 50 cm of the paleosurface. The distinction between the REE profiles in the two paleosols may be related to the difference in the overlying material. The #1 paleosol is overlain by a few meters of sediments and then by basalt, whereas the #2 paleosol is directly overlain by basalt. The LREEs appear to have been mobilized both during chemical weathering of the parental basalt and during later lower-greenschist-facies metamorphism and metasomatism of the paleosols. Remobilization of the REEs during the regional metamorphism of the Fortescue Group is confirmed by a whole-rock Sm-Nd reference isochron of Mt. Roe #1 samples with an age of 2,151 +/- 360 Ma. Variable initial 143Nd/144Nd values of unweathered basalt samples which may represent the paleosol protolith prevents a confident determination of the magnitude of LREE mobility. Both the initial mobilization of the REEs during weathering and the metasomatic remobilization appear to have taken place under redox conditions where Ce was present dominantly as Ce3+, because Ce anomalies are not developed within the sericite zone samples regardless of concentration. Europium anomalies in the paleoweathering profile are somewhat variable and were probably modified by mobilization of Eu2+ at metamorphic conditions. In all samples, the HREEs appear to have been relatively immobile and correlate with Al, Ti, Cr, V, Zr, and Nb. Sm-Nd systematics and REE patterns of four unweathered basalt samples indicate derivation of the Mt. Roe Basalts from a heterogeneous and enriched source having epsilon Nd between -4.0 and -7.4. Initial 143Nd/144Nd values of these basalts are even lower than those reported by NELSON et al. (1992) for Fortescue Group basalts and indicate a substantial crustal component in the generation of Mt. Roe Basalts.

Atmosphere↗
PubMed2005

Live birth following intracytoplasmic sperm injection after a 15-hour weather-related delay in cryopreservation of testicular sperm.

OBJECTIVE: To report a live birth after transfer of cryopreserved blastocysts derived from testicular sperm that were cryopreserved 15 hours after biopsy due to inclement weather. DESIGN: Case report. SETTING: University-affiliated private clinic. PATIENT(S): Couple undergoing IVF with intracytoplasmic sperm injection (ICSI) using testicular extracted sperm for male factor infertility due to unexplained obstructive azoospermia. INTERVENTION(S): An IVF case involving testicular biopsy, cryopreservation, and thawing of testicular tissue, ICSI, embryo freezing, and transfer of cyropreserved blastocysts. MAIN OUTCOME MEASURE(S): The ability to use cryopreserved testicular tissue in which optimal time from biopsy to freezing had been delayed because the weather was inclement. RESULT(S): In spite of a 15-hour delay in processing and cryopreservation of the testicular biopsy, subsequent thawing yielded viable sperm that resulted in viable embryos after ICSI. Transfer of fresh embryos was unsuccessful. However, subsequent use of supernumerary viable blastocysts that were frozen resulted in the live birth of a baby. CONCLUSION(S): A 15-hour delay in processing and cryopreservation of a testicular biopsy did not affect the viability of the extracted sperm after thawing. Although it is desirable to freeze the testicular specimen as soon as possible, the delay in processing in this case due to inclement weather did not affect the potential for fertilization and implantation of a viable cryopreserved blastocyst.

Adult↗
PubMed1980

The weather and deaths from pneumonia.

Changes in the weather are highly significantly correlated with changes in death rate from pneumonia but the association is not a simple one. Two apparently separate periods of weather change are negatively correlated with pneumonia. Both are centred around a time approximately a week before death but one is associated with periods of changed weather of about a week's duration and the other with long-term, probably seasonal, change. Both are almost certainly related to the onset or acquisition of the disease. In addition there is an immediate positive correlation of high humidity and temperature with deaths. This occurs at a time when the patients have had the disease for a week or more and points to the need to avoid these conditions when nursing patients with pneumonia. All three associations are more marked in the elderly and all three operate at all temperatures and humidities met with in Britain. Control of the microenvironment of the elderly is necessary throughout the temperature range.

Age Factors↗
PubMed1970

Studies on the 1967-8 foot-and-mouth disease epidemic. The relation of weather to the spread of disease.

An analysis of the 1967-8 foot-and-mouth disease epidemic with reference to the initial spread, the origin of outbreaks more than 60 km. from the main epidemic area, the series of outbreaks near Worcester, a specific case history and the daily rate of spread of the epidemic, strongly suggests that the weather played a major part in the spread of disease. The two main factors involved in this type of spread are wind and precipitation. It is noted that after the epidemic had been checked, following anticyclonic weather, the association between the weather and the spread of disease was less apparent.

Air Microbiology↗
PubMed2004

Why large-scale climate indices seem to predict ecological processes better than local weather.

Large-scale climatic indices such as the North Atlantic Oscillation are associated with population dynamics, variation in demographic rates and values of phenotypic traits in many species. Paradoxically, these large-scale indices can seem to be better predictors of ecological processes than local climate. Using detailed data from a population of Soay sheep, we show that high rainfall, high winds or low temperatures at any time during a 3-month period can cause mortality either immediately or lagged by a few days. Most measures of local climate used by ecologists fail to capture such complex associations between weather and ecological process, and this may help to explain why large-scale, seasonal indices of climate spanning several months can outperform local climatic factors. Furthermore, we show why an understanding of the mechanism by which climate influences population ecology is important. Through simulation we demonstrate that the timing of bad weather within a period of mortality can have an important modifying influence on intraspecific competition for food, revealing an interaction between climate and density dependence that the use of large-scale climatic indices or inappropriate local weather variables might obscure.

Aging↗
PubMed2000

[Impact of environmental factors on the incidence of posteropative nausea and vomiting. Influence of the weather and cycle of the moon].

OBJECTIVE: In a survey concerning postoperative nausea and vomiting an unexpected high number of the participants stressed the impact of environmental factors, like weather and--even more surprising--the phase of the moon, on the occurrence of postoperative nausea and vomiting (PONV). Thus, the aim of this study was to determine the influence of these factors on the incidence of PONV. METHODS: On 203 days within the 19-month study period, 2488 patients were followed up for at least 24 hours postoperatively to determine the occurrence of PONV. For each day the actual incidence of PONV was compared with the mean predicted risk of PONV calculated with two risk scores for prediction of PONV (Koivuranta, 1997; Apfel, 1998). 32 days with the most significant difference between actual and predicted incidence of PONV were analysed retrospectively by two biometeorological experts, who were blind to the information whether each day was associated with a high or low incidence of PONV, evaluated the possible impact of the weather of these days. To analyse the influence of the cycle of the moon it was prospectively classified into four different phases. RESULTS: The two biometeorologists rated 22 out of the presented 32 days correctly. The likelihood p that this rating happened by chance is 0.0251, assuming that the likelihood for predicting each day correctly is 0.5 (independent Bernoulli-experiments, e.g. throwing a coin). However, days with a high or low incidence of PONV were equally distributed within the four phases of the moon (p = 0.97; chi 2-test with Yates' correction). CONCLUSION: Results from this analysis suggest that the weather may have some impact on the occurrence of PONV. However, our data do not support the hypothesis that the phases of the moon have any influence on this symptom.

Adult↗
PubMed1996

On the belief that arthritis pain is related to the weather.

There is a widespread and strongly held belief that arthritis pain is influenced by the weather; however, scientific studies have found no consistent association. We hypothesize that this belief results, in part at least, from people's tendency to perceive patterns where none exist. We studied patients (n = 18) for more than I year and found no statistically significant associations between their arthritis pain and the weather conditions implicated by each individual. We also found that college students (n = 97) tend to perceive correlations between uncorrelated random sequences. This departure of people's intuitive notion of association from the statistical concept of association, we suggest, contributes to the belief that arthritis pain is influenced by the weather.

Arthritis, Rheumatoid↗
PubMed2001

Correlation between aerosols, deposits and weathering crusts on ancient marbles.

The structure and physicochemical characteristics of weathered surfaces of marble in industrial environments can be attributed to the interconnected evolution of the processes taking place at the atmospheric environment--marble interface. The present work is an attempt to correlate the aerosols of a heavily polluted atmosphere with the different weathering patterns observed on marble surfaces. Energy Dispersive X-Ray Fluorescence, X-Ray Diffraction, Porosimetry, Atomic Absorption, Atomic Emission Spectrometry, Ion Chromatography, Optical Microscopy and Scanning Electron Microscopy results were used together in principal component and discriminant analysis. These analyses were performed on forty six samples of aerosols and eighteen samples of crusts. Other parameters like orientation of the weathered surface, exposure to rainfall, presence of recrystalised calcite and gypsum were also used. The samples were collected from the archaeological site of the Sanctuary of Demeter, located near Eleusis (west of Athens, Greece), where a great number of industries (mainly metallurgical and chemical) cause several environmental problems. The results provide invaluable information on the nature of marble surface decay. The elements determining the chemical composition of the coarse airborne particles are Ca, Si, S, Br and Cl. The presence of gypsum is strongly related to black crusts or loose deposits. Y, Mn and rain exposure, are correlated with each other and related to black-gray crusts. Ca and Sr are correlated with washed-out surfaces. Finally discriminant analysis is proved to be a powerful tool in prediction of the type of decay that will be occur on a marble surface, given the composition and type of the polluted atmosphere.

Aerosols↗
PubMed2006

A role of high impact weather events in waterborne disease outbreaks in Canada, 1975 - 2001.

Recent outbreaks of Escherichia coli O157:H7, Campylobacter, and Cryptosporidium have heightened awareness of risks associated with contaminated water supply. The objectives of this research were to describe the incidence and distribution of waterborne disease outbreaks in Canada in relation to preceding weather conditions and to test the association between high impact weather events and waterborne disease outbreaks. We examined extreme rainfall and spring snowmelt in association with 92 Canadian waterborne disease outbreaks between 1975 and 2001, using case-crossover methodology. Explanatory variables including accumulated rainfall, air temperature, and peak stream flow were used to determine the relationship between high impact weather events and the occurrence of waterborne disease outbreaks. Total maximum degree-days above 0 degrees C and accumulated rainfall percentile were associated with outbreak risk. For each degree-day above 0 degrees C the relative odds of an outbreak increased by a factor of 1.007 (95% confidence interval [CI] = 1.002 - 1.012). Accumulated rainfall percentile was dichotomized at the 93rd percentile. For rainfall events greater than the 93rd percentile the relative odds of an outbreak increased by a factor of 2.283 (95% [CI] = 1.216 - 4.285). These results suggest that warmer temperatures and extreme rainfall are contributing factors to waterborne disease outbreaks in Canada. This could have implications for water management and public health initiatives.

Animals↗