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 > 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 > 72 h), and also at 12–23 and possibly 12–35 h before a cold front (for intervals 49–72 and possibly > 72 h), if the foregoing front was cold or an occlusion front.     

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. This same reasoning might explain the positive association found in an earlier study. A comparison has been made between childbirth and onset as the response variable, and the advantage is emphasized of using data from women whose labor is not induced.     

The influence of weather on asthma in Nairobi

The frequency of bronchial asthma in Nairobi is related to meteorological parameters such as relative humidity, rainfall, dew point temperature, hours of sunshine and dry bulb temperature. Two seasons were taken for study: one cold season (May–August 1975) and one relatively warm season (December 1975–March 1976). It was found that significant correlations occurred at a lag of 2 or 3 days, but not at a lag of 4 or 5 days. Cold and wet weather during the cold season and heat of the day and dryness of the atmosphere during the warm season aggravate asthma in Nairobi.. The frequency of asthmatic attacks is about the same during the two seasons, but the intensity of suffering of a greater majority of patients is more in cold and wet weather than in warm and dry weather. 20–25% of the patients do not feel any relationship between weather and their asthmatic troubles. Nearly twice as many patients suffer from cough with the production of sputum in the cold season than in the warm season. About three times as many patients suffer from bronchospasm in the cold season than in the warm season. Severe asthmatic attacks occur almost equally in both the seasons.     

Day-to-day and seasonal fluctuations of urban mortality in Kyoto,Japan

The study and interpretation of temporal variability in mortality requires the consideration of both exogenous and endogenous influences as underlying factors. In the present paper the relative contribution of fluctuations in daily weather was investigated using the unbiased techniques of lagged cross-correlation and spectral analyses. The study focused on patterns of daily mortality in Kyoto, Japan. Studied herein were total mortality of all ages less accidental, ischemic heart (IHD), cerebrovascular (CVD), cardiovascular (IHD + CVD), cancer and among elderly (over 70 years of age) deaths. The meteorological factors were mean, maximum and minimum daily temperature, mean barometric pressure, mean relative humidity, and mean and maximum wind speed. It was found that after extreme weather conditions, such as heat waves (with mean air temperature in excess of 30°C) or the intrusion of cold waves (with mean air temperature below 0°C), mortality increased to about three times the daily average with a lag effect of usually one—three days and up to one week. Over the year, however, weather fluctuations were found to account statistically for no more than 10% of the overall annual variability in mortality. Importantly, the short-term upswings in mortality were usually accompanied by noticeable drops in the number of deaths on the subsequent days suggesting a triggering effect of external factors. The most weather-sensitive mortality group was people over 70 years of age.     

Absence of harmful effects of protracted negative air ionisation

The absence of harmful effects of protracted negative air ionisation was studied in 5 weather-sensitive women and 5 normal men chosen at random. Negative ions were generated by the Modulion of Amcor-Amron (Herzliya, Israel). The patients were exposed separately during 8 sleeping hours and 8 working hours to the apparatus at 1–2 m distance in a 4 × 4 m room, for 2 months. Thus they were exposed to a daily uptake of 1 × 10⁴ negative ions/cm³ for 16 h/day during 2 months. Urinary 17-KS, 17-OH, adrenaline and noradrenaline excretion was not affected by the negative ionisation. However serotonin, 5-HIAA, histamine and thyroxine excretion — if increased before — diminished by 50% on an average. There were no changes in body weight, blood pressure, pulse, respiratory rate, oral morning temperature, dynamometer grip strength, routine liver function tests, urinary pH, albumen, glucose, ketones, bilirubin, or occult blood, red and white blood count and ECG records. The EEG revealed the typical changes due to negative air ionisation: stabilising of frequency, increased amplitudes, spreading of brainwaves from the perceptive occipital area to the conceptive frontal area and synchronisation of both hemisphere tracings.     

Vernalisation und Thermoperiodismus

Summary Plants of a biennial strain ofHyoscyamus niger were either vernalized at a temperature of +2–3°C. for (F) 17, (G) 31 or (A) 48 days, or exposed to alternating temperatures (E: daily 16 hours at +2–3° and 8 hours at +20°; D: daily 8 hours at +2–3° and 16 hours at +20°) for a period of 48 days. The vernalizing effect, as revealed by the date of shooting, was greatest after treatment A; after treatment E it was even smaller than after treatment G, and very little after treatments F and D (majority of plants strictly vegetative at the end of the experiment). This result does not give any hint towards a connection between vernalization and thermoperiodism. — In contrast to the date of shooting, the date of opening the first flower depends, among others, upon the size of the plants at the start of the cold treatment.     

In vitro differentiation of embryogenic pollen,control by cold treatment and embryo formation inab initio pollen cultures ofNicotiana tabacum var. badischer burley

Summary InNicotiana cold treatment causes differentiation of embryogenic pollen. This differentiation initiates on the plant and is completed in culture. Differentiation on the plant results in pollen dimorphism and differentiation in culture leads to pollen embryogenesis. An increased number of pollen capable of embryogenesis is possible on plants induced to flower in short days and low temperature (8 hours light, 18 °C). These embryogenic pollen on selective isolation, from buds at a petal length of 3.4±0.1 cm, fail to form embryos but do so in the cultures which receive cold treatment at 10 °C for 10 days. To some extent the differentiation of embryogenic pollen can be completed on plants induced to flower at 15 °C and embryogenic pollen from such plants form embryos at a low frequency which can be substantially increased on giving the cultures a cold treatment. The frequency of embryogenesis is higher in cultures of 15 °C plants than those of 18 °C plants. Low temperature requirements at two stages—to the plant and to the culture—are essential and complimentary for embryogenesis inab initio pollen cultures.Cold treatment causes repression of gametophytic differentiation and this results in the differentiation of embryogenic potential. The embryogenic pollen, unlike gametophytic pollen, are not fully differentiated structures. They are unable to divide and form embryos in presence of metabolic inhibitors such as actinomycin-D and cycloheximide.     

A statistical investigation into the relationship between meteorological parameters and suicide

Many previous studies of relationships between weather and suicides have been inconclusive and contradictory. This study investigated the relationship between suicide frequency and meteorological conditions in people who are psychologically predisposed to commit suicide. Linear regressions of diurnal temperature change, departure of temperature from the climatic norm, mean daytime sky cover, and the number of hours of precipitation for each day were performed on daily suicide totals using standard computer methods. Statistical analyses of suicide data for days with and without frontal passages were also performed. Days with five or more suicides (clusterdays) were isolated, and their weather parameters compared with those of nonclusterdays. Results show that neither suicide totals nor clusterday occurrence can be predicted using these meteorological parameters, since statistically significant relationships were not found. Although the data hinted that frontal passages and large daily temperature changes may occur on days with above average suicide totals, it was concluded that the influence of the weather parameters used, on the suicide rate, is a minor one, if indeed one exists.     

Effects of Extreme Weather on Reproductive Success in a Temperate-Breeding Songbird

The frequency of extreme meteorological events such as heat waves and rainstorms is predicted to increase with climate change. However, there is still little information about how extreme weather influences reproduction in animals. It may not only affect breeding success but might also alter offspring sex ratio if males and females are differentially sensitive to meteorological conditions during development. We investigated the relationship between meteorological conditions and reproductive success over 6 years in a house sparrow population in central Europe. We found that hatching success increased with the number of extremely hot days (daily maximum >31°C) and decreased with the number of extremely cold days (<16°C) during incubation, although the latter effect held only for clutches with relatively short incubation periods. Fledging success was unrelated to weather variables. However, the frequency of extremely hot days had a negative effect on fledglings’ body mass and tarsus length, although both of these traits were positively related to average temperature. Additionally, fledglings’ body mass increased with the length of period without rainfall before fledging. Male to female ratio among fledglings did not differ from 1:1 and did not vary with weather variables. The magnitude of the effects of extreme meteorological events was usually small, although in some cases comparable to those of ecologically relevant predictors of reproductive success. Our results indicate that meteorological conditions have complex effects on breeding success, as the effects of extreme weather can differ between different aspects of reproduction and also from the effects of overall meteorological conditions.     

Effect of Temperature on Hospital Admissions for Myocardial Infarction in a Subarctic Area

In a study of the effect of mean daily temperature on the admission and fatality rates of 771 patients with myocardial infarction the admission rate was found to be significantly higher on cold (temperature below 0°C.) than on warm (temperature above 0°C.) days. The fatality rate was almost equal in cold and warm weather. Thus the seasonal fluctuation in the admission rate of patients with myocardial infarction is probably due to a direct effect of environmental temperature.     

Weather Effects on the Patterns of People's Everyday Activities: A Study Using GPS Traces of Mobile Phone Users

This study explores the effects that the weather has on people''s everyday activity patterns. Temperature, rainfall, and wind speed were used as weather parameters. People''s daily activity patterns were inferred, such as place visited, the time this took place, the duration of the visit, based on the GPS location traces of their mobile phones overlaid upon Yellow Pages information. Our analysis of 31,855 mobile phone users allowed us to infer that people were more likely to stay longer at eateries or food outlets, and (to a lesser degree) at retail or shopping areas when the weather is very cold or when conditions are calm (non-windy). When compared to people''s regular activity patterns, certain weather conditions affected people''s movements and activities noticeably at different times of the day. On cold days, people''s activities were found to be more diverse especially after 10AM, showing greatest variations between 2PM and 6PM. A similar trend is observed between 10AM and midnight on rainy days, with people''s activities found to be most diverse on days with heaviest rainfalls or on days when the wind speed was stronger than 4 km/h, especially between 10AM–1AM. Finally, we observed that different geographical areas of a large metropolis were impacted differently by the weather. Using data of urban infrastructure to characterize areas, we found strong correlations between weather conditions upon people''s accessibility to trains. This study sheds new light on the influence of weather conditions on human behavior, in particular the choice of daily activities and how mobile phone data can be used to investigate the influence of environmental factors on urban dynamics.     

Distribution of euphausiids in the Kuroshio front and warm water tongue with special reference to the surface aggregation of Euphausia pacifica

The distribution of euphausiids and other macrozooplankton wasinvestigated in and around the Kuroshio front formed in theKa.shima-nada Sea. Japan. during the summer of 1993. Zooplanktonwere dominated by copepods, chaetognaths and euphausiids. andtheir biomass was significantly higher at the frontal stations.Eighteen species belonging to six genera of euphausiids werecollected. The species composition and community structure ofeuphausiids changed drastically with the ‘areas’corresponding to the hydrological conditions. In the area underthe influence of the Kuroshio. most euphausiids were warm-waterspecies. In contrast. euphausiids found in the frontal areawere those usually predominating in subarctic or cold Oyashiowaters. In the area of the warm water tongue. where warm Kuroshiowater lay above cold Oyashio water, the species compositionof euphausiids represented a mixture of both warm- and cold-waterspecies. Surface aggregations of Euphausia pacifica were observedin the frontal area during the night. The biomass and densityof the aggregations ranged between 90 and 136 mg C m^–3and 164 and 238 md. m^–3 respectively. These aggregationswere mostly made up of immature individuals of < 12 mm. Passivetransportation by convergent flow at the front seems to explainthe observed surface aggregations of E.pacifica.     

Safety Precautions to be Observed with Cooled Premixed Gases

The gas delivered from a cylinder of Entonox (50% nitrous oxide and 50% oxygen) may not contain adequate quantities of oxygen if the cylinder has been cooled and then allowed to warm up in a vertical position.The composition of gas delivered from cylinders cooled to not lower than –40° C. remains unaltered if the cylinders are rewarmed for 24 hours in a horizontal position at a temperature of not less than 5° C.Cylinders of Entonox delivered in cold weather should be stored in a horizontal position at 5° C. or more for at least 24 hours before use.     

Weather and the incidence of urinary stone colics in the Province of Florence

The present study analyses the case histories of urinary stone colics recorded at the hospital Val di Sieve (Florence) during the period 1962–1971 by comparing the weather conditions of the 353 days during which the cases occurred, with the weather conditions of a sample of normal reference days.From the analysis it seems to emerge that a hot and — at the same time — dry weather, as well as wide changes in air pressure, may favour in predisposed individuals the onset of urinary stone colics.     

Spatial and Temporal Association of Outbreaks of H5N1 Influenza Virus Infection in Wild Birds with the 0°C Isotherm

Wild bird movements and aggregations following spells of cold weather may have resulted in the spread of highly pathogenic avian influenza virus (HPAIV) H5N1 in Europe during the winter of 2005–2006. Waterbirds are constrained in winter to areas where bodies of water remain unfrozen in order to feed. On the one hand, waterbirds may choose to winter as close as possible to their breeding grounds in order to conserve energy for subsequent reproduction, and may be displaced by cold fronts. On the other hand, waterbirds may choose to winter in regions where adverse weather conditions are rare, and may be slowed by cold fronts upon their journey back to the breeding grounds, which typically starts before the end of winter. Waterbirds will thus tend to aggregate along cold fronts close to the 0°C isotherm during winter, creating conditions that favour HPAIV H5N1 transmission and spread. We determined that the occurrence of outbreaks of HPAIV H5N1 infection in waterbirds in Europe during the winter of 2005–2006 was associated with temperatures close to 0°C. The analysis suggests a significant spatial and temporal association of outbreaks caused by HPAIV H5N1 in wild birds with maximum surface air temperatures of 0°C–2°C on the day of the outbreaks and the two preceding days. At locations where waterbird census data have been collected since 1990, maximum mallard counts occurred when average and maximum surface air temperatures were 0°C and 3°C, respectively. Overall, the abundance of mallards (Anas platyrhynchos) and common pochards (Aythya ferina) was highest when surface air temperatures were lower than the mean temperatures of the region investigated. The analysis implies that waterbird movements associated with cold weather, and congregation of waterbirds along the 0°C isotherm likely contributed to the spread and geographical distribution of outbreaks of HPAIV H5N1 infection in wild birds in Europe during the winter of 2005–2006.     

Effect of cerebral electro-therapy on neurohormone excretion in weather-sensitive patients

Use of a cerebral electro-therapy (CET) device, called PENTA, for weather-sensitive patients is described here. It applies 6–45 V D.C. monopolar triangular shaped pulses of 0.75 ms duration, allowing an input of 0–600 mA mean current via 2 frontal and 1 indifferent occipital electrode. To avoid adaptation it is programmed to two alternating frequencies of 20 and 65 Hz. Its successful application to 15 cases of disturbed neuro-endocrine regulation in weather sensitivity is reported. It resulted in cures for 3–12 months, depending on the type of weather sensitivity treated. The mechanism of CET treatment may be due to a bio-feedback on the limbicsystem, involving hypothalamic and pituitarian hormones. The normalising effects described here were followed up by neurohormone urinalysis of 17-KS, 17-OH, adrenaline, noradrenaline, serotonin, 5-HIAA, histamine and thyroxine.—This method proved itself as a valuable and objective tool for psychosomatic complaints due to weather sensitivity.     

Relationships between sudden weather changes in summer and mortality in the Czech Republic, 1986–2005

The study examines the relationship between sudden changes in weather conditions in summer, represented by (1) sudden air temperature changes, (2) sudden atmospheric pressure changes, and (3) passages of strong atmospheric fronts; and variations in daily mortality in the population of the Czech Republic. The events are selected from data covering 1986–2005 and compared with the database of daily excess all-cause mortality for the whole population and persons aged 70 years and above. Relative deviations of mortality, i.e., ratios of the excess mortality to the expected number of deaths, were averaged over the selected events for days D−2 (2 days before a change) up to D+7 (7 days after), and their statistical significance was tested by means of the Monte Carlo method. We find that the periods around weather changes are associated with pronounced patterns in mortality: a significant increase in mortality is found after large temperature increases and on days of large pressure drops; a decrease in mortality (partly due to a harvesting effect) occurs after large temperature drops, pressure increases, and passages of strong cold fronts. The relationship to variations in excess mortality is better expressed for sudden air temperature/pressure changes than for passages of atmospheric fronts. The mortality effects are usually more pronounced in the age group 70 years and above. The impacts associated with large negative changes of pressure are statistically independent of the effects of temperature; the corresponding dummy variable is found to be a significant predictor in the ARIMA model for relative deviations of mortality. This suggests that sudden weather changes should be tested also in time series models for predicting excess mortality as they may enhance their performance.     

Influence of Cold Stress on the Preliminary Enrichment Time Needed for Detection of Enterohemorrhagic Escherichia coli in Ground Beef by PCR

The influence of cold stress at 4 and 0°C on the detection time as assessed by impedance technology (Bactometer; Biomérieux, Marcy l’Etoile, France) of different enterohemorrhagic Escherichia coli (EHEC) strains was determined. Although there is some variation in susceptibility among EHEC strains, prolonged exposure of EHEC to cold stress, i.e., 4 and 5 days at 4 and 0°C, respectively, in general significantly increased their detection time. This reflects an increase of the lag-phase time caused by cold stress. Two EHEC strains were selected to determine the minimum preliminary enrichment time that would ensure a positive PCR detection of low numbers of verotoxin-producing E. coli (VTEC; 2 to 2 × 10⁵ CFU/25 g) inoculated into ground beef (25 g) and stored at 4 or −20°C for 8 and 14 days, respectively. Incubation times of 6 and 9 h of 1 to 10 CFU/g and 1 to 10 CFU/25 g, respectively, were sufficient for PCR detection of VTEC in ground beef when analysis was performed immediately after inoculation (no cold stress). When cells are exposed to cold stress (4 or −20°C) a 24-h enrichment period is recommended. Restriction of enrichment time to 9 h under these circumstances decreases the sensitivity of PCR detection to 80 CFU/g. Hence, to obtain maximum sensitivity, PCR detection of VTEC in naturally contaminated ground beef should be performed after 24 h of enrichment.     

Plankton distribution across a slope current-induced front in the southern Bay of Biscay

Relatively warm (12.50–12.75°C) and high-salinity[<35.640 practical salinity units (PSU)] water flowing eastwardwas detected at the shelf-break during a cruise carried Outin the southern Bay of Biscay in Spring 1987. The slope currentinduced the formation of a convergent front separating well-mixedoceanic waters from haline-stratified coastal waters. Very highconcentrations of dissolved oxygen (295 µmol kg^–1)and chlorophyll a(>4.5 mg m^–3) were found at the outeredge of the frontal boundary. Small autotrophic flagellatesdominated the phytoplankton community. Primary production peakedat the boundary region. Estimated phytoplankton growth ratesindicated that active growth was taking place, with lower turnovertimes integrated over the water column at the frontal station(2.5–5 days) than at coastal (1.5–2.8 days) or oceanic(1.5–3.5 days) stations. The lowest doubling times (1–2days) were calculated for surface frontal populations. Accumulationof zooplankton was also observed associated with the convergentphysical structure, although this relationship was less markedthan for phytoplankton. Copepods, mainly Paracalanus parvus,Acartia clausi and Oithona helgolandica, formed the bulk ofthe mesozooplankton biomass. Compatibility between the sizeof phytoplankton cells and copepod size spectra indicate highfood availability for these animals, particularly in the vicinityof the front. The distribution of fish eggs and fish larvaewas also coupled with the slope current-induced front. Sardinelarvae were more abundant at the coastal side of the front,whereas larval stages of blue whiting reached the highest densitiesat off-shelf stations. Larvae of lamellibranch molluscs andbryozoa were restricted to nearshore waters, as the frontalboundary prevented larval dispersion to the open ocean. Theresults presented in this paper suggest that the Iberian slopecurrent and its associated shelf-break frontal structure werecrucial in controlling phytoplankton primary production, activityof grazers, distribution of larvae of fishes and benthic invertebrates,and ultimately in determining the structure of the pelagic foodweb in the southern Bay of Biscay during the seasonal periodof vertical mixing.