Predicting days of high allergenic risk during Betula pollination using weather types

The aim of this study was to build up a picture of the influence of meteorological conditions on pollen and pollinosis, taking account of weather types, pollen concentrations in the air and pollinosis symptoms, with the aim of preventing allergic responses. The study took place in Burgundy from 1996 to 1998, during the pollination of the birch (Betula), which is the most important arborean allergen in this region. We used daily pollen data from four Hirst volumetric traps, identified weather types by Bénichou’s classification, and obtained data on the occurrence of rhinitis, conjunctivitis, asthma and coughing from a sample of 100 patients. These data were analysed by multiple-component analysis. The results show that pollen dispersal is favoured by windy conditions, low relative humidity, precipitation below 2 mm and temperatures above 6°C. Such weather also favours pollinosis, but other particular meteorological situations, even if they do not assist pollen dispersal, can act directly on the development of symptoms: a decrease of temperature (3°C) led to the development of rhinitis and conjunctivitis, while strong winds were associated with many cases of conjunctivitis and asthma, owing to the irritant effect of cold or wind; asthma was favoured by temperature inversions with fog, probably because such weather corresponds to high levels of pollution, which act on bronchial hyperreactivity. Because the weather types favouring pollination and pollinosis are predicted by the meteorological office, this can constitute a tool for reducing the effect of high-risk allergenic days. Received: 12 December 2000 / Revised: 24 April 2001 / Accepted: 9 May 2001     

The effects of temperature, altitude and latitude on the arrival and departure dates of the swallow Hirundo rustica in the Slovak Republic

The (barn) swallow Hirundo rustica is a traditional harbinger of spring in many countries of the Northern Hemisphere. This paper uses information on the arrival and departure dates of the swallow in the Slovak Republic for the 30 years 1961–1985 and 1996–2000. Records were taken at 19 locations throughout the Republic representing an altitude range from 105 m to 760 m. Monthly temperature data were constructed from six meteorological stations. With the use of regression techniques, trends towards later arrival, earlier departure and the effects of latitude, altitude and temperature are all apparent. Received: 25 October 2000 / Revised: 23 April 2001 / Accepted: 23 April 2001     

Influence of weather and climate on subjective symptom intensity in atopic eczema

The frequent clinical observation that the course of atopic eczema, a skin disease involving a disturbed cutaneous barrier function, is influenced by climate and weather motivated us to analyse these relationships biometrically. In the Swiss high-mountain area of Davos the intensity of itching experienced by patients with atopic eczema was evaluated and compared to 15 single meteorological variables recorded daily during an entire 7-year observation period. By means of univariate analyses and multiple regressions, itch intensity was found to be correlated with some meteorological variables. A clear-cut inverse correlation exists with air temperature (coefficient of correlation: –0.235, P<0.001), but the effects of water vapour pressure, air pressure and hours of sunshine are less pronounced. The results show that itching in atopic eczema is significantly dependent on meteorological conditions. The data suggest that, in patients with atopic eczema, a certain range of thermo-hygric atmospheric conditions with a balance of heat and water loss on the skin surface is essential for the skin to feel comfortable. Received: 9 August 1999 / Revised: 10 July 2000 / Accepted: 11 July 2000     

Total protein and isozyme characterization in the flax zygotic embryo during development

Flax zygotic embryogenesis was studied for isozyme patterns of acid phosphatase and esterase and for content of total proteins. For acid phosphatase, six multiple molecular forms or isozymes, were identified during flax zygotic embryo development. For esterase, six isozymes were expressed during zygotic flax embryogenesis. Some of the isozymes were expressed during entire embryogenesis, and some were only transiently expressed or appeared near maturation. The amount of total proteins was very low at early embryogenesis and proteins in a range from 26.6 kDa to 97.4 kDa were expressed. During further flax embryo development the protein spectra became more diverse and the quantity of total proteins increased. Proteins ranging from 3.4 kDa to 97.4 kDa were present, and proteins of 20 kDa to 36.5 kDa were expressed in the highest amount. The results are discussed with reference to selected information in the literature. Received: 16 October 2000 / Revision accepted: 20 April 2001     

Polymorphism for interspecific hybridisation within a population of wild radish (Raphanus raphanistrum) pollinated by oilseed rape (Brassica napus)

The within-population polymorphism of wild radish (Raphanus raphanistrum) for interspecific hybridisation with two cultivars of oilseed rape (Brassica napus) was investigated by hand crossing experiments and fluorescence microscopy. Wide variability among plants was observed in the ability of oilseed rape pollen to germinate on the wild radish stigma; the frequency of pistils showing pollen tubes ranged from 0 to 1, depending on the female plant. The ratio of fertilised ovules to the total number of ovules in ovaries where pollen tubes arrived ranged from 0.02 to 0.51. Overall, the results provide evidence for the presence of different phenotypes. In 40% of the plants, pistils had no or very few pollen tubes and few fertilised ovules. In 23%, the foreign pollen tubes grew through the style towards the ovary, but had low ovule fertilisation efficiency. The remaining 37% showed a large number of pollen tubes in the style and frequent ovule fertilisation, and two plants showed no difference between foreign and conspecific pollen. With regard to post-zygotic barriers, pollen germination and ovule fertilisation represent minor barriers to interspecific hybridisation between oilseed rape and wild radish. It is suggested that the effectiveness of these barriers could be improved through plant breeding; this could reduce the risk of gene flow from transgenic oilseed rape to populations of wild relatives. Received: 15 April 2001 / Accepted: 24 May 2001     

Statistical downscaling of monthly mean air temperature to the beginning of flowering of Galanthus nivalis L. in Northern Germany

 We have examined the relationship between phenological data and concurrent large-scale meterological data. As phenological data we have chosen the beginning of the flowering of Galanthus nivalis L. (flowering date) in Northern Germany, and as large-scale meteorological data we use monthly mean near-surface air temperatures for January, February and March. By means of canonical correlation analysis (CCA), a strong linear correlation between both sets of variables is identified. Twenty years of observed data are used to build the statistical model. To validate the derived relationship, the flowering date is downscaled from air temperature observations of an independent period. The statistical model is found to reproduce the observed flowering dates well, both in terms of variability as well as amplitude. Air temperature data from a general circulation model of climate change are used to estimate the flowering date in the case of increasing atmospheric carbon dioxide concentration. We found that at a time of doubled CO₂ concentration (expected by about 2035) G. nivalis L. in Northern Germany will flower ∼2 weeks and at the time of tripled CO₂ concentration (expected by about 2085) ∼4 weeks earlier than presently. Received: 7 August 1996 / Accepted: 27 November 1996     

MS32-regulated timing of callose degradation during microsporogenesisin Arabidopsis is associated with the accumulation of stacked rough ER in tapetal cells

  In the male sterile32(ms32)mutant in Arabidopsis thaliana, pollen development is affected during meiosis of pollen mother cells (PMCs). In normal wild-type (WT) anthers, callose is deposited around PMCs before and during meiosis, and after meiosis the tetrads have a complete callose wall. In ms32, PMCs showed initial signs of some callose deposition before meiosis, but it was degraded soon after, as was part of the cellulosic wall around the PMCs. The early dissolution of callose in ms32 was associated with the occurrence of extensive stacks of rough ER (RER) in tapetal cells. The stacks of RER were also observed in the WT tapetum, but at a later stage, i.e., after the tetrads were formed and when callose is normally broken down for release of microspores. Based on these observations it is suggested that: (1) callose degradation around developing microspores is linked to the formation of RER in tapetal cells, which presumably synthesize and/or secrete callase into the anther locule, and (2) mutation in MS32 disrupts the timing of these events. Received: 27 April 1999 / Revision accepted: 21 June 1999     

High-mortality days during the winter season: comparing meteorological conditions across 5 US cities

While the relationship between weather and human health has been studied from various perspectives, this study examines an alternative method of analysis by examining weather conditions on specific high-mortality days during the winter season. These high-mortality days, by definition, represent days with dramatic increases in mortality and the days with the highest mortality. By focusing solely on high-mortality days, this research examines the relationship between weather variables and mortality through a synoptic climatology, environment-to circulation approach. The atmospheric conditions during high-mortality days were compared to the days prior and the days not classified as high-mortality days. Similar patterns emerged across all five locations despite the spatial and temporal variability. Southern locations had a stronger relationship with temperature changes while northern locations showed a greater relationship to atmospheric pressure. Overall, all high-mortality days were associated with warmer temperatures, decreased pressure, and a greater likelihood of precipitation when compared to the previous subset of days. While the atmospheric conditions were consistent across all locations, the importance of the lag effect should not be overlooked as a contributing factor to mortality during the winter season. Through a variety of diverse, methodological approaches, future studies may build upon these results and explore in more detail the complex relationship between weather situations and the impact of short-term changes in weather and health outcomes.     

Embryological study on gynogenesis in onion (Allium cepa L.)

Haploid induction in onion can, to date, be induced only via gynogenesis by culturing unfertilized flowers, ovaries or ovules. The process of haploid embryo induction has been macroscopically well studied, but only limited data exist from microscopic examination of ovule development status at the inoculation stage and of the origin of gynogenic embryos. Microscopic studies were carried out using individual donor plants with relatively high embryo induction frequencies (45.9 embryos formed per 100 flowers, on average, for 2 years). Ovaries from flower bud culture were fixed at 1 week intervals up to the 7th week of culture. These were compared with pollinated ovaries at 1 or 2 weeks after pollination. In total, 1428 unfertilized embryo sacs were examined. The results indicate that, at the time of inoculation, ovules within ovaries 2.0–3.0 mm in diameter contained two- or four-nucleate embryo sacs in the smallest ovaries to mature embryo sacs in the largest ovaries. It seems likely that the embryos are actually induced from ovaries cultured at the immature stage. After 1 or 2 weeks in culture, the egg apparatus primarily consisted of distinctly enlarged synergids and the egg cell, which was often detached from the micropylar pole. But free nuclear endosperm was also formed. From the 2nd to 7th week in culture, formation of haploid embryos (from globular to the almost mature cylindrical stage) was detected in 5.7% of the ovules. Their origin, for several reasons, was most likely the egg cell. In addition, ovules containing endosperm only (3.6%) and ovules containing the egg apparatus (0.5%) or both endosperm and embryo (0.4%) were detected. This observation is probably unique and has not yet been reported in other species studied. Received: February 2001 / Revision accepted: 20 April 2001     

Spelt-specific alleles in HMW glutenin genes from modern and historical European spelt ( Triticum spelta L.)

A partial promoter region of the high-molecular weight (HMW) glutenin genes was studied in two wheat specimens, a 300 year-old spelt (Triticum spelta L.) and an approximately 250 year-old bread wheat (Triticum aestivum L.) from Switzerland. Sequences were compared to a recent Swiss landrace T. spelta ’Oberkulmer.’ The alleles from the historical bread wheat were most similar to those of modern T. aestivum cultivars, whereas in the historical and the recent spelt specific alleles were detected. Pairwise genetic distances up to 0.03 within 200 bp from the HMW Glu-A1-2, Glu-B1-1 and Glu-B1-2 alleles in spelt to the most-similar alleles from bread wheat suggest a polyphyletic origin. The spelt Glu-B1-1 allele, which was unlike the corresponding alleles in bread wheat, was closer related to an allele found in tetraploid wheat cultivars. The results are discussed in context of the origin of European spelt. Received: 22 July 2000 / Accepted: 27 April 2001     

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.     

Influence of weather on emergency transport events coded as stroke: population-based study in Japan

Studying the relation between incidence of stroke and weather is difficult because it requires large-scale community-based data collection. Despite the lack of strong evidence that weather conditions influence stroke incidence, many clinicians feel that meteorological conditions influence the onset of stroke. This study examined whether emergency events related to stroke are influenced by meteorological factors and was based on computerized records of emergency medical transport services in a Japanese city during the period January 1992–December 2003. A total of 53,585 patients transported for an event coded as stroke were analyzed in relation to meteorological factors such as temperature, humidity, and barometric pressure. Poisson regression analysis was applied to clarify the influence of daily meteorological conditions on the daily incidence of emergency transport due to events coded as stroke. Ordinary least squares regression analysis was used to evaluate the influence of weather, defined as the combination of meteorological parameters, on the occurrence of emergency transport due to events coded as stroke. Daily mean ambient temperature and daily mean relative humidity showed a statistically significant negative effect on the incidence of the emergency transport events for both men and women (P<0.001). Daily mean barometric pressure was not significantly related to these events. The occurrence of a holiday was negatively related to the incidence (P<0.001). Dry weather and cool weather were likely to shift the circadian curve of the incidence upward. Thus, occurrence of emergency transport due to events coded as stroke is likely to be associated with weather conditions.     

Natural very-low-frequency sferics and headache

Very-low-frequency (VLF) atmospherics or sferics are pulse-shaped alternating electric and magnetic fields which originate from atmospheric discharges (lightning). The objective of the study was threefold: (i) to analyse numerous parameters characterizing the sferics activity with regard to their suitability for field studies, (ii) to identify meteorological processes related to the sferics activity and (iii) to investigate the possible association of sferics with pain processes in patients suffering from migraine- and tension-type headaches. Over a period of 6 months (July through December) the sferics activity in the area of Giessen (Germany) was recorded. Three sferics parameters were chosen. The number of sferics impulses per day, the variability of the impulse rate during a day and the variability in comparison to the preceding day were correlated with weather processes (thunderstorm, temperature, vapour pressure, barometric pressure, humidity, wind velocity, warm sector). Significant correlations were obtained during the summer months (July, August) but not during the autumn months (October, November, December). During autumn, however, the sferics activity was correlated with the occurrence of migraine-type headaches (r=0.33, P<0.01) recorded by 37 women who had filled out a headache diary over a period of 6 months (July–December). While the thunderstorm activity was very intense during July and August, no relationship between sferics and migraine was found. In summer, tension-type headaches were associated with meteorological parameters such as temperature (r=0.42, P<0.01) and vapour pressure (r=0.28, P<0.05). Although the sferics activity can explain a small percentage of the variation in migraine occurrence, a direct influence was more likely exerted by visible or otherwise perceptible weather conditions (thunderstorms, humidity, vapour pressure, warm sector, etc.) than by the sferics activity itself. Received: 9 January 2001 / Revised: 1 May 2001 / Accepted: 9 May 2001     

A comparative analysis of heat waves and associated mortality in St. Louis, Missouri – 1980 and 1995

 This research investigates heat-related mortality during the 1980 and 1995 heat waves in St. Louis, Missouri. St. Louis has a long history of extreme summer weather, and heat-related mortality is a public health concern. Heat waves are defined as days with apparent temperatures exceeding 40.6°C (105°F). The study uses a multivariate analysis to investigate the relationship between mortality and heat wave intensity, duration, and timing within the summer season. The heat wave of 1980 was more severe and had higher associated mortality than that of 1995. To learn if changing population characteristics, in addition to weather conditions, contributed to this difference, changes in population vulnerability between 1980 and 1995 are evaluated under simulated heat wave conditions. The findings show that St. Louis remains at risk of heat wave mortality. In addition, there is evidence that vulnerability has increased despite increased air-conditioning penetration and public health interventions. Received: 12 August 1997 / Revised: 12 January 1998 / Accepted: 13 February 1998     

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.     

Some properties of a pheromone allowing individual recognition, from the scats of an Australian lizard, Egernia striolata

  The Australian lizard, Egernia striolata, can distinguish its own scats from those of unfamiliar conspecific individuals. This appears to be unrelated to diet, because there is no difference in the response to scats from unfamiliar lizards fed on diets that are the same or different from the test lizard. The signal that induces the response is not a visual or tactile property of scat structure, because test lizards respond equally to crushed and intact scats. We suggest that a pheromone is secreted onto the scat as it is produced. Water solutions of scats did not contain signal components that allowed lizards to distinguish their own scats from others. However, solutions of scats in dichloromethane (DCM) retained unique characteristics, and test lizards responded more strongly to the solution from scats of an unfamiliar lizard that to the solution from their own scats. Further fractionation of the DCM solution in pentane and in methanol led to loss of the unique signals needed for individual recognition, but those were restored when the pentane and methanol fractions were recombined. We infer that these lizards can distinguish between scats of different individuals on the basis of signals they receive from a complex combination of chemicals. Received: 14 December 1998 / Received in revised form: 9 April 1999 / Accepted: 12 April 1999     

Is supernumerary chromatin involved in gametophytic apomixis of polyploid plants?

Gametophytic apomixis, or unreduced embryo sac development that results in asexual reproduction through seeds, occurs in several families of angiosperms and must be polyphyletic in origin. The molecular mechanisms underlying gametophytic apomixis have not been discovered and are the subject of intense investigation. A common feature of almost all apomicts is their polyploid nature. From genetic mapping studies in both monocots and dicots, there is low genetic recombination associated with a single (rarely two), dominant locus for either aposporous or diplosporous embryo sac formation. In Pennisetum squamulatum and Cenchrus ciliaris, some DNA sequences mapping to the apospory locus are unique to apomictic genotypes and apparently hemizygous. This sequence divergence at the apomixis locus could be a consequence of genome rearrangements and isolation from genetic recombination, both of which may have contributed to the definition of a chromosomal region as supernumerary. The possible involvement of supernumerary chromatin, formed as a result of interspecific hybridization, in the origin of apomixis, is explored here. Received: 26 October 2000 / Revision accepted: 5 April 2001     

Correlations between the modelled potato crop yield and the general atmospheric circulation

Biology-related indicators do not usually depend on just one meteorological element but on a combination of several weather indicators. One way to establish such integral indicators is to classify the general atmospheric circulation into a small number of circulation types. The aim of present study is to analyse connections between general atmospheric circulation and potato crop yield in Estonia. Meteorologically possible yield (MPY), calculated by the model POMOD, is used to characterise potato crop yield. Data of three meteorological stations and the biological parameters of two potato sorts were applied to the model, and 73 different classifications of atmospheric circulation from catalogue 1.2 of COST 733, domain 05 are used to qualify circulation conditions. Correlation analysis showed that there is at least one circulation type in each of the classifications with at least one statistically significant (99%) correlation with potato crop yield, whether in Kuressaare, Tallinn or Tartu. However, no classifications with circulation types correlating with MPY in all three stations at the same time were revealed. Circulation types inducing a decrease in the potato crop yield are more clearly represented. Clear differences occurred between the observed geographical locations as well as between the seasons: derived from the number of significant circulation types, summer and Kuressaare stand out. Of potato varieties, late 'Anti' is more influenced by circulation. Analysis of MSLP maps of circulation types revealed that the seaside stations (Tallinn, Kuressaare) suffer from negative effects of anti-cyclonic conditions (drought), while Tartu suffers from the cyclonic activity (excessive water).     

Utility of barley and wheat simple sequence repeat (SSR) markers for genetic analysis of Hordeum chilense and tritordeum

A selection of 36 wheat and 35 barley simple sequence repeat markers (SSRs) were studied for their utility in Hordeum chilense. Nineteen wheat and nineteen barley primer pairs amplified consistent H. chilense products. Nine wheat and two barley SSRs were polymorphic in a H. chilense mapping population, producing codominant markers that mapped to the expected homoeologous linkage groups in all but one case. Thirteen wheat and 10 barley primer pairs were suitable for studying the introgression of H. chilense into wheat because they amplified H. chilense products of distinct size. Analysis of wheat/H. chilense addition lines showed that the H. chilense products derived from the expected homoeologous linkage groups. The results showed that wheat and barley SSRs provide a valuable resource for the genetic characterization of H. chilense, tritordeums and derived introgression lines. Received: 20 November 2000 / Accepted: 12 April 2001     

Analysis of genetic similarity detected by AFLP and coefficient of parentage among genotypes of sugar cane ( Saccharum spp.)

Despite the economical importance of sugar cane, until the present-date no studies have been carried out to determine the correlation of the molecular-based genetic similarity (GS) and the coefficient of parentage (f)-estimates generated for cultivars. A comprehensive knowledge of the amount of genetic diversity in parental cultivars, could improve the effectiveness of breeding programmes. In this study, amplified fragment length polymorphism (AFLP) and pedigree data were used to investigate the genetic relationship in a group of 79 cultivars (interspecific hybrids), used as parents in one of the Brazilian breeding programmes, and four species of Saccharum (Saccharum sinense, Saccharum barberi and two of Saccharum officinarum) . The objectives of this study were to assess the level of genetic similarity among the sugar-cane cultivars and to investigate the correlation between the AFLP-based GS and f, based on pedigree information. Twenty one primer combinations were used to obtain the AFLP molecular markers, generating a total of 2,331 bands, of which 1,121 were polymorphic, with a polymorphism rate, on average, of 50% per primer combination. GSs were determined using Jaccard’s similarity coefficient, and a final dendrogram was constructed using an unweighted pair-group method using arithmetic average (UPGMA). AFLP-based GS ranged from 0.28 to 0.89, with a mean of 0.47, whereas f ranged from 0 to 0.503, with a mean of 0.057. Cluster analysis using GS divided the genotypes into related subgroups suggesting that there is important genetic relationship among the cultivars. AFLP-based GS and f were significantly correlated (r = 0.42, P < 0.001), thus the significance of this r value suggests that the AFLP data may help to more-accurately quantify the degree of relationship among sugar-cane cultivars. Received: 27 November 2000 / Accepted: 27 April 2001