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     

Influence of weather and climate on the fibrinogen content of human blood

During the periods June–October 1969 and January 1970 from 792 different male blood donors the fibrinogen content, blood sedimentation rate, haemoglobin content and blood pressure were determined in relation to the age of the donors. A number of significant relationships were found which could partly explain the long term (yearly) fluctuations in the blood sedimentation rate pattern of healthy male population groups. It is pointed out that these studies may prove to be important for the study of the effect of meteorological stimuli on arteriosclerotic heart diseases.Of each donor 4.9 ml blood was mixed with 0.1 ml sodium citrate (20%) and centrifuged. 0.1 ml plasm was used for the determination.     

Impact of weather variability on spatial and seasonal dynamics of dissolved and suspended nutrients in water column of meromictic Lake Shira

Depths of thermocline and the redox zone, concentrations of dissolved and suspended carbon, and nitrogen and phosphorus in seston were measured in the pelagial of the saline meromictic Lake Shira (southern Siberia) in different years (2007–2011); the relationship of the values for those parameters with air-temperature variations was assessed. Positive correlations between both air temperatures in the previous year and the depth of the redox zone in winter and air temperature in April and the thermocline depth in summer were revealed. In the mixolimnion, the ratio of total nitrogen to total phosphorus almost always exceeded the Redfield ratio (16: 1); seston deficiency both in nitrogen and phosphorus was monitored in different seasons and at various depths. The amount of seston in the mixolimnion in summer almost doubled the amount of seston in winter and was directly related with the depth of the thermocline. In the monimolimnion, seston was rich in nitrogen and phosphorus. The amount of seston in the monimolimnion varied in different years and depended both on the air temperature in the previous year and the size of the zone.     

Linguistic dimensions of weather and climate perception

The purpose of this research was to explore the latent dimensions that underlie people’s use of adjectives that can describe weather and climate conditions. A sample of 1,011 university undergraduate students residing the southeastern United States evaluated the weather and climate of that region using 143 English language adjectives. Data were collected over a two-year period during various weather and seasonally related climatic conditions. Polychoric correlations among the adjective ratings were calculated; the matrix of correlations was factor analyzed. Twelve underlying factors related to weather and climate perceptions were observed: 1. threatening, severe, violent, 2. dismal, drab, dark, 3. cold and wintry, 4. hot and summery, 5. tranquil and pleasant, 6. stormy and wet, 7. bright and clear, 8. blowing and blustery, 9. damp and moist, 10. cloudy and cool, 11. predictable and unchanging, and 12. hazy and dusty. A second-order factor analysis revealed two factors pertaining to weather valence: 1. bad or extreme and 2. good or routine conditions. The study results were noteworthy in revealing some of the basic linguistic dimensions along which people perceive and experience weather and climate at the current time in the southeastern United States. The study also represents the use of a new technique for biometeorologists to use in assessing climate perceptions in culturally and climatically diverse regions.     

Operational seasonal forecasting of crop performance

Integrated, interdisciplinary crop performance forecasting systems, linked with appropriate decision and discussion support tools, could substantially improve operational decision making in agricultural management. Recent developments in connecting numerical weather prediction models and general circulation models with quantitative crop growth models offer the potential for development of integrated systems that incorporate components of long-term climate change. However, operational seasonal forecasting systems have little or no value unless they are able to change key management decisions. Changed decision making through incorporation of seasonal forecasting ultimately has to demonstrate improved long-term performance of the cropping enterprise. Simulation analyses conducted on specific production scenarios are especially useful in improving decisions, particularly if this is done in conjunction with development of decision-support systems and associated facilitated discussion groups. Improved management of the overall crop production system requires an interdisciplinary approach, where climate scientists, agricultural scientists and extension specialists are intimately linked with crop production managers in the development of targeted seasonal forecast systems. The same principle applies in developing improved operational management systems for commodity trading organizations, milling companies and agricultural marketing organizations. Application of seasonal forecast systems across the whole value chain in agricultural production offers considerable benefits in improving overall operational management of agricultural production.     

The impact of temperature variability on wheat yields

With current annual production at over 600 million tonnes, wheat is the third largest crop in the world behind corn and rice, and an essential source of carbohydrates for millions of people. While wheat is grown over a wide range of environments, it is common in the major wheat‐producing countries for grain filling to occur when soil moisture is declining and temperature is increasing. Average global temperatures have increased over the last decades and are predicted to continue rising, along with a greater frequency of extremely hot days. Such events have already been reported for major wheat growing regions in the world. However, the direct impact of past temperature variability and changes in averages and extremes on wheat production has not been quantified. Attributing changes in observed yields over recent decades to a single factor such as temperature is not possible due to the confounding effects of other factors. By using simulation modelling, we were able to separate the impact of temperature from other factors and show that the effect of temperature on wheat production has been underestimated. Surprisingly, observed variations in average growing‐season temperatures of ±2 °C in the main wheat growing regions of Australia can cause reductions in grain production of up to 50%. Most of this can be attributed to increased leaf senescence as a result of temperatures >34 °C. Temperature conditions during grain filling in the major wheat growing regions of the world are similar to the Australian conditions during grain filling. With average temperatures and the frequency of heat events projected to increase world‐wide with global warming, yield reductions due to higher temperatures during the important grain‐filling stage alone could substantially undermine future global food security. Adaptation strategies need to be considered now to prevent substantial yield losses in wheat from increasing future heat stress.     

Soil profile gravel concentration and its effect on rainfed crop yields

Summary Soil characteristics in the crop root zone are critical to soil water and nutrient availability to rainfed crops and determine crop production in coarse textured soils. A four-year field study was conducted in the foot-hills of North Himalayas near Chandigarh (India) on a coarse textured soil (Gravelly udic ustocrepts) to evaluate the effect of varying soil profile gravel concentration on the yield of rainfed crops of Taramira (Eruca sativa Mill.) in winter followed by maize (Zea mays L.), sorghum (Sorghum vulgare Pers.), cowpea (Vigna unguiculata L.) and sesamum (Sesamum indicum L.) in summer. Taramira gave a mean grain yield of 683, 410 and 275 kg ha^–1 at gravel concentration (GC) of 18, 28 and 40 percent by volume in the surface one metre soil depth. The grain and forage yield of summer crops decreased with the increasing GC. The gross monetary returns decreased in the order: Sorghum fodder, cowpea, sesamum and maize. The dilution of soil mass with increasing GC and corresponding decrease in nutrient and water holding capacity of the soil appears to have depressed the crop yields. The results indicated that the legume which can also conserve rainwater with dense canopy like cowpea or crops having vigorous fibrous root system and are relatively drought tolerant like sorghum may provide better economic returns in light textured soil containing gravel upto 40 percent.     

Temporal changes in climatic variables and their impact on crop yields in southwestern China

Knowledge of variability in climatic variables changes and its impact on crop yields is important for farmers and policy makers, especially in southwestern China where rainfed agriculture is dominant. In the current study, six climatic parameters (mean temperature, rainfall, relative humidity, sunshine hours, temperature difference, and rainy days) and aggregated yields of three main crops (rice: Oryza sativa L., oilseed rape: Brassica napus L., and tobacco: Nicotiana tabacum L.) during 1985–2010 were collected and analyzed for Chongqing—a large agricultural municipality of China. Climatic variables changes were detected by Mann-Kendall test. Increased mean temperature and temperature difference and decreased relative humidity were found in annual and oilseed rape growth time series (P?<?0.05). Increased sunshine hours were observed during the oilseed rape growth period (P?<?0.05). Rainy days decreased slightly in annual and oilseed rape growth time series (P?<?0.10). Correlation analysis showed that yields of all three crops could benefit from changes in climatic variables in this region. Yield of rice increased with rainfall (P?<?0.10). Yield of oilseed rape increased with mean temperature and temperature difference but decreased with relative humidity (P?<?0.01). Tobacco yield increased with mean temperature (P?<?0.05). Path analysis provided additional information about the importance and contribution paths of climatic variables to crop yields. Temperature difference and sunshine hours had higher direct and indirect effects via other climatic variables on yields of rice and tobacco. Mean temperature, relative humidity, rainy days, and temperature difference had higher direct and indirect effects via others on yield of oilseed rape.     

Winter grass cover crop effects on nematodes and yields of double cropped soybean

Rye (Secale cereale L.), wheat (Triticum aestivum L.), and annual ryegrass (Lolium multiflorum Lam.) are commonly double cropped with soybean (Glycine max L.). Recent greenhouse studies have shown variability in plant-parasitic nematode response to cool season grass species and cultivars. However, subsequent soybean performance was not affected by previous annual ryegrass cultivar in the green-house. The objective of this research was to determine whether winter cover crop species or cultivars affected nematode populations and subsequent performance of soybean in teh field. Four cultivars of annual ryegrass, wheat, and rye, and a fallow control were seeded on a Suffolk sandy loam (fine-loamy, siliceous, thermic Typic Hapuldult) soil in each of three years. Nematode-susceptible soybeans were seeded following forage removal. Soil samples for nematode counts were taken immediately before soybean harvest each year. In another experiment, one cultivar each of annual ryegrass, wheat, and rye, and a fallow control were followed by three soybean cultivars selected for differing nematode susceptibility. Grass cultivars did not affect nematode populations under succedding soybean. The only nematodes affected by grass species in either experiment were Pratylenchus spp., Heterodera glycines Ichinohe, and Tylenchorhynchus claytoni (Kofoid and White) Chitwood. Nematode population means were usually low following ryegrass and high following the fallow control. High soybean yields followed the fallow control, and low soybean yields followed annual ryegrass.     

Influence of climate on emergency department visits for syncope: role of air temperature variability

Background

Syncope is a clinical event characterized by a transient loss of consciousness, estimated to affect 6.2/1000 person-years, resulting in remarkable health care and social costs. Human pathophysiology suggests that heat may promote syncope during standing. We tested the hypothesis that the increase of air temperatures from January to July would be accompanied by an increased rate of syncope resulting in a higher frequency of Emergency Department (ED) visits. We also evaluated the role of maximal temperature variability in affecting ED visits for syncope.

Methodology/Principal Findings

We included 770 of 2775 consecutive subjects who were seen for syncope at four EDs between January and July 2004. This period was subdivided into three epochs of similar length: 23 January–31 March, 1 April–31 May and 1 June–31 July. Spectral techniques were used to analyze oscillatory components of day by day maximal temperature and syncope variability and assess their linear relationship.There was no correlation between daily maximum temperatures and number of syncope. ED visits for syncope were lower in June and July when maximal temperature variability declined although the maximal temperatures themselves were higher. Frequency analysis of day by day maximal temperature variability showed a major non-random fluctuation characterized by a ∼23-day period and two minor oscillations with ∼3- and ∼7-day periods. This latter oscillation was correlated with a similar ∼7-day fluctuation in ED visits for syncope.

Conclusions/Significance

We conclude that ED visits for syncope were not predicted by daily maximal temperature but were associated with increased temperature variability. A ∼7-day rhythm characterized both maximal temperatures and ED visits for syncope variability suggesting that climate changes may have a significant effect on the mode of syncope occurrence.     

Effects of precipitation and temperature on crop production variability in northeast Iran

Climate variability adversely impacts crop production and imposes a major constraint on farming planning, mostly under rainfed conditions, across the world. Considering the recent advances in climate science, many studies are trying to provide a reliable basis for climate, and subsequently agricultural production, forecasts. The El Niño-Southern Oscillation phenomenon (ENSO) is one of the principle sources of interannual climatic variability. In Iran, primarily in the northeast, rainfed cereal yield shows a high annual variability. This study investigated the role played by precipitation, temperature and three climate indices [Arctic Oscillation (AO), North Atlantic Oscillation (NAO) and NINO 3.4] in historically observed rainfed crop yields (1983–2005) of both barley and wheat in the northeast of Iran. The results revealed differences in the association between crop yield and climatic factors at different locations. The south of the study area is a very hot location, and the maximum temperature proved to be the limiting and determining factor for crop yields; temperature variability resulted in crop yield variability. For the north of the study area, NINO 3.4 exhibited a clear association trend with crop yields. In central locations, NAO provided a solid basis for the relationship between crop yields and climate factors.     

Impact of climate change on crop nutrient and water use efficiencies

Implicit in discussions of plant nutrition and climate change is the assumption that we know what to do relative to nutrient management here and now but that these strategies might not apply in a changed climate. We review existing knowledge on interactive influences of atmospheric carbon dioxide concentration, temperature and soil moisture on plant growth, development and yield as well as on plant water use efficiency (WUE) and physiological and uptake efficiencies of soil-immobile nutrients. Elevated atmospheric CO₂ will increase leaf and canopy photosynthesis, especially in C3 plants, with minor changes in dark respiration. Additional CO₂ will increase biomass without marked alteration in dry matter partitioning, reduce transpiration of most plants and improve WUE. However, spatiotemporal variation in these attributes will impact agronomic performance and crop water use in a site-specific manner. Nutrient acquisition is closely associated with overall biomass and strongly influenced by root surface area. When climate change alters soil factors to restrict root growth, nutrient stress will occur. Plant size may also change but nutrient concentration will remain relatively unchanged; therefore, nutrient removal will scale with growth. Changes in regional nutrient requirements will be most remarkable where we alter cropping systems to accommodate shifts in ecozones or alter farming systems to capture new uses from existing systems. For regions and systems where we currently do an adequate job managing nutrients, we stand a good chance of continued optimization under a changed climate. If we can and should do better, climate change will not help us.     

Choice of selection environment for improving crop yields in saline areas

Spatial variability in salt-affected fields is normally very high. Thus, most salinity affected lands are actually comprised of many micro-environments, ranging from low to high salinity in the same field. The evidence on testing genotypes across a broad range of salinity levels shows that the genotype-by-salinity level interaction is commonly large. Thus, breeding for saline areas can be compared to what has been known as breeding for wide adaptation. The target environments both for breeding for saline soils or for wide adaptation are actually a population of many possible environments, for which there exists a significant component of genotype-by-environment(G x E) interaction. Thus it is possible to study the merit of potential strategies for breeding for salinity tolerance using the tools that have been developed for the study of breeding for wide adaptation. The evidence from selection and breeding experiments for wide adaptation seems to favour testing on a representative subset of environments, including stress and non-stress locations; but the choice of these locations is complicated by the multidimensional nature of G x E. However, in the case of salt stress, the crop-yield response functions to salinity are well known. This paper presents an attempt to systematise the choice of the optimum environment(s) to select for improved yield under saline soil conditions, based on the three-piece linear equation presented by Maas and Hoffman (1977) and the theory of direct and indirect responses to selection. It is proposed that three saline levels should be enough to make a valid estimation of the suitability of a number of selection strategies. A worked example with data from a set of grain sorghum inbred lines tested on ten saline levels shows that the same selection strategies would be chosen using the information from the ten saline levels as that obtained using the two extremes and one intermediate level.     

甘肃陇东地区季节冻土变化对气候变暖的响应

受气候变暖的影响,季节冻土的冻结、融化及持续时间都发生了较大变化。运用陇东地区8个气象站1971-2005年温度、冻土观测资料,分析了该地气候变化对季节冻土的影响。结果表明：自20世纪70年代以来,该地冬季气温升高了2．7℃,30cm的冻土冻结时间大约推后了10d,冻土融化时间提前了10d,冻土持续时间缩短了20d左右;35年来平均最大冻结深度减少了约20cm;随着气候的持续变暖,最大冻土深度将进一步减少,预计2050年至少比现在减少15cm左右,对未来建设工程的设计及施工有较大影响。