High Temperature Days Research Articles

RESEARCH OF THE INFLUENCE OF THE HOOK LOAD OF THE UNSTABLE CHARACTER ON THE OPERATING INDICATORS OF THE ENERGY MEANS

When the machine-tractor unit (MTU) performs agricultural operations, there are significant fluctuations in the hook load, that is, the load of the tractor engine is unsteady in its characteristics, and the degree of unevenness of the moment of engine resistance during this period can reach 30-40%. To reduce the fluctuations of the hook load and eliminate the unevenness of the moment of engine resistance, the most promising direction is the increase in the moment of inertia of the MTU. The technical solution can be the installation of an additional device in the form of a flywheel driven by a power take-off shaft. The presence of an additional flywheel will contribute to smoothing the load oscillations, which will lead to an increase in the working speed, and, consequently, to an increase in the productivity of the machine and tractor unit. This particularly applies to the conditions of the Amur region, since the soils of this region are mainly loaming of varying degrees of severity, while the presence of a permafrost base during the spring field works strengthens the influence of the unsteady character of the hook load on the tractor output indicators. This is explained by the fact that the process of thawing the soil according to the depth is fairly uneven due to high daily temperature changes, which ultimately increases the uneven nature of the hook load of power resources in field work. Especially clearly its manifestation with increasing of working speeds of the agricultural unit. The foregoing shows that the problem of reducing the unstable character of the hook load on the output parameters of mobile energy equipment is currently topical, and the solution is in demand in engineering and agro-industrial production. In this connection, the purpose of the proposed studies is to reduce the influence of the unsteady nature of the traction load on the output indicators of the power facility when installing an additional device in the form of a flywheel. In the present work, we propose the construction of a perspective device for reducing the influence of unsteady load on the output indicators of the power tool (wheeled tractor) and the results of studies of the influence of the regime parameters of the additional flywheel on the operational performance of the power tool.

Comparison of health risks by heat wave definition: Applicability of wet-bulb globe temperature for heat wave criteria

Despite the active applications of thermal comfort indices for heat wave definitions, there is lack of evaluation for the impact of extended days of high temperature on health outcomes using many of the indices. This study compared the impact of heat waves on health outcomes among different heat wave definitions based on thermal comfort and air temperature. We compared heat waves in South Korea (cities and provinces) for the warm season for 2011–2014, using air temperature, heat index (HI), and web-bulb globe temperature (WBGT). Heat waves were defined as days with daily maximum values of each index at a specified threshold (literature-based, the 90th and 95th percentiles) or above. Distributed lag non-linear models and meta-analysis were used to estimate risk of mortality and hospitalization for all-causes, cardiovascular causes, respiratory causes and heat disorders during heat wave days compared to non-heat wave days. WBGT identified 1.15 times longer maximum heat wave duration for the study periods than air temperature when the thresholds were based on 90th and 95th percentiles. Over the study period, for heat waves defined by WBGT and HI, the Southwestern region showed the highest total number of heat wave days, whereas for air temperature the longest heat wave days were identified in the southeastern region. The highest and most significant impact of heat waves were found by WBGT for hospitalization from heat disorders (Relative risk = 2.959, 95% CI: 1.566–5.594). In sensitivity analyses using different structure of lags and temperature metrics (e.g., daily mean and minimum), the impacts of heat waves on most health outcomes substantially increased by using WBGT for heat wave definitions. As a result, WBGT and its thresholds can be used to relate heat waves and heat-related diseases to improve the prevention effectiveness of heat wave warnings and give informative health guidelines according to the range of WBGT thresholds.

Ambient air pollution exposure and risk of migraine: Synergistic effect with high temperature

BackgroundMigraine is a chronic and agonizing neurological disorder prevalent worldwide. Although its pathogenesis remains unclear, limited evidence exists on the role of air pollution. ObjectiveWe aimed to assess the association of short-term air pollution exposure with migraine in conjunction with the synergistic effect of temperature. MethodsWe identified 18,921 patients who visited emergency departments (EDs) for migraine as a primary disease in Seoul from the national emergency database between 2008 and 2014. We conducted a time-stratified, case-crossover analysis to compare levels of particles <2.5 μm (PM2.5), particles <10 μm (PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), and carbon monoxide (CO) on ED visit days and those on the control days matched to day of the week, month, and year. We evaluated the synergistic effects of air pollution and temperature using an interaction term. ResultsHigher air pollution levels were significantly associated with risk of migraine over various lag structures. In the best fitting lags, the odds ratio (OR) associated with an interquartile range increase of PM2.5, PM10, NO2, O3, and CO was 1.031 (95% CI: 1.010–1.053), 1.032 (95% CI: 1.007–1.057), 1.053 (95% CI: 1.022–1.085), 1.034 (95% CI: 1.001–1.067), and 1.029 (95% CI: 1.005–1.053), respectively. The SO2 effect was positive but not significant (OR 1.019 [95% CI: 0.991–1.047]). The PM effect was significantly stronger on high-temperature days (above the 75th percentile) than on low-temperature days (PM2.5, high: OR 1.068, low: OR 1.021, Pinteract = 0.03; PM10, high: OR 1.066, low: OR 1.014, Pinteract = 0.02). ConclusionOur study provides new evidence that air pollution exposure may trigger migraine especially on high-temperature days, and this finding may contribute in establishing preventive measures against migraine.

Comparative Analysis of Urban Heat Island Intensities in Chinese, Russian, and DPRK Regions across the Transnational Urban Agglomeration of the Tumen River in Northeast Asia

Quantification of the spatial pattern of urban heat island intensities across the transnational urban agglomeration of the Tumen River is important for the promotion of sustainable regional development. This study employed Landsat images and MODIS LST data obtained in 2016 to determine the intensity of urban heat islands in this region, enabling direct comparison of data from the sub-regions of China, Democratic People’s Republic of Korea (DPRK), and Russia. The average urban heat island intensity for the region was found to be 1.0 °C, with the highest intensity of 3.0 °C occurring during the summer time. The intensity of urban heat islands on the Chinese side was higher than on the other two sides, with city size, socio-economic development levels and vegetation coverage significantly affect their intensity. Urban heat island effects in Chinese cities in the region contribute increases in maximum summer temperatures and the number of high-temperature days that pose a threat to the health of their residents. The factors that influence urban heat island intensities in these cities and the impacts of urban heat island effects on the quality of life and health of residents are discussed. Therefore, it is desirable to reduce the impact of urban heat island effects on cities in the region by increasing the area of green spaces they contain, as well as controlling their size and population.

Nocturnal activity in wild chimpanzees (Pan troglodytes): Evidence for flexible sleeping patterns and insights into human evolution.

We investigated occurrences and patterns of terrestrial nocturnal activity in wild chimpanzees (Pan troglodytes) and modelled the influence of various ecological predictors on nocturnal activity. Data were extracted from terrestrial camera-trap footage and ecological surveys from 22 chimpanzee study sites participating in the Pan African Programme: The Cultured Chimpanzee. We described videos demonstrating nocturnal activity, and we tested the effects of the percentage of forest, abundance of predators (lions, leopards and hyenas), abundance of large mammals (buffalos and elephants), average daily temperature, rainfall, human activity, and percent illumination on the probability of nocturnal activity. We found terrestrial nocturnal activity to occur at 18 of the 22 study sites, at an overall average proportion of 1.80% of total chimpanzee activity, and to occur during all hours of the night, but more frequently during twilight hours. We found a higher probability of nocturnal activity with lower levels of human activity, higher average daily temperature, and at sites with a larger percentage of forest. We found no effect of the abundance of predators and large mammals, rainfall, or moon illumination. Chimpanzee terrestrial nocturnal activity appears widespread yet infrequent, which suggests a consolidated sleeping pattern. Nocturnal activity may be driven by the stress of high daily temperatures and may be enabled at low levels of human activity. Human activity may exert a relatively greater influence on chimpanzee nocturnal behavior than predator presence. We suggest that chimpanzee nocturnal activity is flexible, enabling them to respond to changing environmental factors.

Analysis of photovoltaic arrays efficiency for reduction of building cooling load in hot climates

This research work presents shading of building in hot and dry climate areas using rooftop photovoltaic arrays. Electrical power generation using photovoltaic arrays helps in reducing dependency on the utility grid. Areas with high intensities of solar radiation for a longer duration of time create high daily temperature. The Kingdom of Saudi Arabia (KSA) falls in high temperature and very low humidity climate zone. KSA has increased electricity tariff rates by 260% since 1 January 2018, has planned goals of generation of 9.5 gigawatts of renewable energy by 2030, and has ideas of constructing a self-sustainable city by the Red Sea. Energy analysis performed in this research is to calculate benefits of placing photovoltaic arrays on a rooftop of Buildings. These benefits include the electrical energy production and reduction of building cooling load by shading effect on a rooftop. By placing photovoltaic arrays on rooftop, up to 23% energy saving of cooling load can be achieved. The net annual output of photovoltaic generation per panel is discussed by adding energy generation and saving in cooling load of the building. The distance between the photovoltaic arrays is optimized for maximum benefits of electrical energy and saving in cooling loads. Practical application: Photovoltaic arrays on rooftops for shading effect have practical benefits of energy savings in hot environment areas where high solar irradiance heat up the buildings. Photovoltaic arrays provide shading and energy generations which is a step towards zero energy buildings.

Cyanobacterial Community Composition and Bacteria-Bacteria Interactions Promote the Stable Occurrence of Particle-Associated Bacteria.

Within meso/eutrophic freshwater ecosystems the dominance of cyanobacterial blooms during summer months has substantial impacts on ecosystem function with the production of toxins and subsequent induction of hypoxia altering food web structures and biogeochemical cycles. Cyanobacterial aggregates are extensively colonized by heterotrophic bacteria that provide the cyanobacteria with key nutrients and contribute towards remineralisation of organic matter. Here we sampled from five sites within a shallow eutrophic pond over a 6 months period, relating changes in the abundance of particle-associated heterotrophic taxa to phytoplankton abundance, toxin gene copies and physiochemical properties. The abundance of a majority of particle-associated bacteria were stable, in that they persisted despite perturbation. Cyanobacterial species abundance more likely correlated with stable rather than unstable bacteria and unstable bacteria were associated with allochthonous (terrestrial) organic matter. The occurrence of the most stable bacteria was correlated with large numbers of other bacteria suggesting bacteria-bacteria interactions have implications for the stable occurrence of microorganisms on particles. Freshwater ecosystems are frequently inundated with fresh nutrients in the form of surface runoff and experience an increasing number of high temperature days. In addition to increasing the severity and longevity of cyanobacterial blooms, run-off changes the nature of the particle-associated community compromising stability. This disruption has the potential to drive changes in the carbon and nitrogen cycles and requires further attention.

An study on the incidence of heat stroke and explore it's prediction model in Pudong New Area of Shanghai from 2013-2017

Objective: To know the incidence of heat stroke and explore it's prediction model in Pudong New Area of Shanghai. Methods: An epidemiological investigation was conducted on heat stroke cases in Pudong New Area of Shanghai from 2013 to 2017. Daily temperature data during this period were collected to explore it's influence. Results: 246 heat stroke cases were reported and investigated, 70.3% (173/246) of them were male. 170 cases are severe heat stroke, accounting for 69.1%. 28 patients died, accounting for 11.4% of all cases of heat stroke, and 16.5% (28/170) of severe heat stroke cases. Thermoplegia (56.5%, 96/170) was the most popular type among severe heat stroke cases. Heat prostration, heat cramps and mixed type account for 17.1% (29/170) , 12.4% (21/170) and 14.0% (24/170) respectively. Scatter plot and linear regression demonstrated that there was a significant linear relation between number of high temperature days and number of heat stroke cases (P<0.01) . And the prediction model is: Predictive number of annual heat stroke cases=β×Number of annual high temperature days+Intercept. Leave-one-out cross validation result shows that the predictive number of annual heat stroke cases from 2013 to 2017 were 85.7%, 90.9%, 83.3%, 91.9 and 84.3% respectively. Conclusion: There was a significant linear relation between number of high temperature days and number of heat stroke cases in Pudong New Area. The related work arrangement for heat stroke prevention could be well planed according to the prediction model.

Yield and grain weight responses to post-anthesis increases in maximum temperature under field grown wheat as modified by nitrogen supply

High-temperatures reduce yield of wheat and with global warming episodes of heat waves (only few days of high maximum temperatures) during grain filling will become more frequent. It has been recently reported that the magnitude of the yield penalties imposed by high temperatures under field conditions may interact with nitrogen (N) availability both in barley and maize. We determined, under field conditions, the penalties imposed by post-anthesis high-temperatures waves (increased maximum –but not minimum– temperatures during part of the grain filling period) on wheat yield under contrasting soil N supply during two consecutive years. The high temperature treatment was imposed for 10 d starting 10 d after anthesis by placing over the crops transparent polyethylene film (125 μm) mounted on wood structures of 1.5 m height above the ground. This high-temperature and the unheated controls were imposed on 5 modern and well adapted cultivars under contrasting N availabilities (376, 268 and 68 KgN ha−1). Averaged across N conditions, high-temperature treatments reduced yield by c. 1.5 Mg ha−1 (a loss of c. 17%) even though the treatment was rather mild in terms of different average temperature during grain filling. The magnitude of the loss was consistently shaped by the N condition in which the treatment was imposed: yield penalty produced by high-temperature increased from less than 1 to 2.6 Mg ha−1 (which represents losses from 10 to 25%) in parallel with the increased N supply. The penalties were related to both yield components (grain number and average grain weight) which also were more severely penalised under high than under low N supply. As episodes of high-temperature waves will become more frequent in the future the tools used to establish the needs of N fertilisation should be revised as the rates maximising yield (or gross margin) might induce higher sensitivities to these episodes. Also simulation models used to upscale physiological responses to regional or even global domains might need to be revised to include the effect of heat waves (which would be larger per °C increase than what is estimated from experiments increasing temperature during the whole day and over longer periods) as well as the interaction with N supply.

Rhodobacter sp. Rb3, an aerobic anoxygenic phototroph which thrives in the polyextreme ecosystem of the Salar de Huasco, in the Chilean Altiplano.

The Salar de Huasco is an evaporitic basin located in the Chilean Altiplano, which presents extreme environmental conditions for life, i.e. high altitude (3800m.a.s.l.), negative water balance, a wide salinity range, high daily temperature changes and the occurrence of the highest registered solar radiation on the planet (> 1200Wm-2). This ecosystem is considered as a natural laboratory to understand different adaptations of microorganisms to extreme conditions. Rhodobacter, an anoxygenic aerobic phototrophic bacterial genus, represents one of the most abundant groups reported based on taxonomic diversity surveys in this ecosystem. The bacterial mat isolate Rhodobacter sp. strain Rb3 was used to study adaptation mechanisms to stress-inducing factors potentially explaining its success in a polyextreme ecosystem. We found that the Rhodobacter sp. Rb3 genome was characterized by a high abundance of genes involved in stress tolerance and adaptation strategies, among which DNA repair and oxidative stress were the most conspicuous. Moreover, many other molecular mechanisms associated with oxidative stress, photooxidation and antioxidants; DNA repair and protection; motility, chemotaxis and biofilm synthesis; osmotic stress, metal, metalloid and toxic anions resistance; antimicrobial resistance and multidrug pumps; sporulation; cold shock and heat shock stress; mobile genetic elements and toxin-antitoxin system were detected and identified as potential survival mechanism features in Rhodobacter sp. Rb3. In total, these results reveal a wide set of strategies used by the isolate to adapt and thrive under environmental stress conditions as a model of polyextreme environmental resistome.

Impact of extreme weather events on coconut productivity in three climatic zones of Sri Lanka

Abstract Coconut is a major plantation crop in Sri Lanka, a tropical island in the Indian Ocean. The highest coconut production is found in Gampaha, Kurunegala and Puttalam districts which belong to the wet, intermediate and dry zones respectively. An increase in the frequency of extreme weather events has been observed during the recent past. This study, the first of its kind, was undertaken to assess the impact of extreme events on coconut productivity. Meteorological and coconut productivity data were obtained for the period 1995–2015 from six estates, two estates representing each of the above-mentioned districts. Extreme events were defined using maximum daily temperature (Tmax) and daily rainfall. The 90th percentiles of the daily distribution of rainfall and Tmax in the reference period were used to define high rainfall and high temperature days respectively. The days with their rainfall below the 10th percentile were defined as low rainfall days. Regression analyses between coconut productivity and the number of extreme events during the first four months after flowering were performed. In the dry zone the number of high rainfall and high Tmax days during the said period had a negative influence on productivity and the mean rainfall had a positive influence on productivity. In the intermediate zone the number of high rainfall events and the mean Tmax of the same period had a negative impact on coconut productivity. In the wet zone, while the number of extreme weather events had no influence on the coconut productivity, the mean Tmax during the first four months since flowering had a negative impact on coconut productivity.

Environmental and management factors contributing to variability in flesh colour of a red kiwifruit cultivar in New Zealand

Abstract Consistency of flesh colouration is important for commercial acceptance of red-fleshed Actinidia chinensis cultivars, but colour variation between and within orchards is widely reported. Physiological and environmental factors reported to influence this variability include parent cane and shoot type, ploidy of pollen parent, and high temperatures, specifically cumulative time above 25 °C over the growing season. However, the impacts of temperature in a temperate climate (e.g. New Zealand) on colour variability have not been explored. Light, a commonly reported influence on anthocyanin expression in other plants, does not directly influence red kiwifruit colour but the indirect effects of light exposure are unknown. This study explored the colour variability found in eight New Zealand red kiwifruit orchards spread across five regions and examined correlations of environmental conditions (temperature and light exposure) with fruit colour. Two harvests were collected from each orchard in 2014, with two further harvests being conducted in one orchard in 2015. It was found that the variation between orchards and regions was larger than within orchards but no clear regional patterns existed. A significant relationship existed between softer fruit and stronger red colouration, measured by hue angle and outer pericarp colour score. A significant relationship also existed between increased flesh colour and higher number of leaf layers, lower estimated light exposure, and paler skin colour, with skin colour score having the largest effect on flesh colour. No significant correlations between temperature in March and colour expression were found, but three out of the four lower colour orchards had significantly more hours above 25 °C during March. Collectively, these data suggest that full colour development may be promoted directly by carbohydrate supply from a denser canopy and is probably negatively affected by excessive fruit temperatures that may be more common under poorly-developed canopies or in areas with high daily maximum temperatures.

Is extreme climate or moderate climate more conducive to longevity in China?

Climate is closely related to human longevity. In China, there are many climate types. According to national population censuses from 1982 to 2000, most provinces with a high ratio of centenarians are located in western and northwestern China far from the sea; these areas are characterized by a dry, cold climate, very high altitude, very high daily temperature range, strong winds, and partial hypoxia. Meanwhile, provinces with a high ratio of nonagenarians from 1982 to 2000 are located in southern China near the sea. Previous studies have attributed the high ratio of centenarians in western and northwestern China to the extreme local climate. However, centenarians in these areas decreased greatly in 2010, whereas residents in southern China frequently reached 90 to 100years old in 2010. This study aims to explain this strange phenomenon and find whether extreme climate in Tibetan plateau and northwestern China or moderate climate in southern China is more conducive to longevity. The study found that mortality rate in Tibetan plateau is much higher than southern China, then a population evolution experiment was proposed to compare longevity indicators between low mortality rate and high mortality rate and shows that longevity indicators will decrease in the near future and increase above their original levels after several decades when the mortality rate is decreased. Results of this study show individuals in northwestern China do not live as long as those in eastern and southern China. A moderate climate is more conducive to longevity than extreme climate in China. The longevity of a region should be judged by long-term longevity indicators.

Control of growth cessation and floral initiation in red raspberry (Rubus idaeus L.) cultivars of diverse origin in controlled and natural environments

Abstract The aim of the investigation was to assess and compare the environmental limits for growth cessation and floral initiation in a range of new and established biennial-fruiting red raspberry (Rubus idaeus L.) cultivars of diverse origin under phytotron and field conditions. The results confirmed that growth cessation and floral initiation in biennial-fruiting red raspberry are jointly controlled by the interaction of low temperature and short days (SD). When transferred from non-inductive high temperature and long day (LD) conditions to naturally decreasing autumn daylengths at varying phytotron temperatures on 18 August, growth immediately levelled off and ceased completely within 2 weeks in all cultivars at 9 °C. Serial dissections of lateral buds revealed that floral initiation simultaneously took place. At 15 °C on the other hand, the plants continued growing and remained vegetative until around 15 September when the daylength had decreased to approximately 13 h. The change to 9 °C resulted in an immediate but short-lasting floral induction response that did not bring about initiation in buds situated near the base of the canes, as was the case at 15 °C. At 18 °C, marginal floral induction took place only in the cultivars ‘Glen Ample’, ‘Balder’ and ‘Vene’, even at photoperiods down to 10 h, whereas at 21 °C, all cultivars grew vegetatively regardless of daylength conditions. However, exceptions were some plants of ‘Vene’ and ‘Anitra’ that initiated terminal flowers at 18 and 21 °C and flowered directly without chilling (so-called tip flowering). Although some cultivars of Northern origin ceased growing and initiated floral primordia somewhat earlier (at longer photoperiods) than those of more southerly origin, the differences were relatively minor and not consistent (no latitudinal cline). Results obtained in the field under decreasing autumn temperature and daylength conditions agreed closely with the results in the phytotron. We therefore conclude that results obtained with raspberry in properly controlled daylight phytotron experiments are generally applicable to field conditions.

近46年温州市平阳县气温变化特征

利用1971~2016年平阳县国家气象观测站月平均气温、年平均气温、日极端最高、最低气温等观测资料，采用气候倾向率、滑动平均法、M-K趋势检验和突变分析方法对平阳县年均气温和各季节气温的变化特征进行分析。结果表明：平阳县年均气温呈升高趋势，并以20世纪90年代后期为界，经历“冷–暖”两个时期，增温率为0.36℃/10a，低于浙江省平均水平。年平均气温在1997年发生突变现象，由平稳的气温变化转变为显著上升趋势。2003年之后气温呈明显上升趋势；极端最高气温增温趋势显著，增温率为0.069℃/年。高温日数呈显著上升趋势，升幅0.36 d/年，并在2003年发生增加性突变；极端最低气温增温率为0.002℃/年，气温增幅不大。低温日数呈显著下降趋势，降幅0.53 d/年，并在1989年发生减少性突变；四个季节的气温年际变化特征均表现为增温，其中秋季的气温倾向率最大，冬季最小，与年平均气温序列的相关上春季最高，冬季最小。 Based on the observation data of monthly average air temperature, annual mean temperature, extreme maximum and minimum air temperature of the National Meteorological Observatory in Pingyang from 1971 to 2016, the climate change tendency, the average moving average method, the MK trend test and the mutation analysis method were used to analyze the data of the annual average temperature and the seasonal variation of temperature in Pingyang County. The results show that the annual average temperature in Pingyang County is on an upward trend. In the late 1990s, it experienced two periods of “cold-warm”, and the rate of temperature increase was 0.36˚C/10a, lower than the average level of Zhejiang Province. The annual average temperature was abruptly changed in 1997, which was changed from a steady temperature change to a significant upward trend. After 2003, the temperature showed a clear upward trend; extreme maximum temperature warming trend is significant, the rate of warming is 0.069˚C/year. The number of high temperature days showed a significant upward trend, an increase of 0.36 d/year, and in 2003 increased mutations; extreme minimum temperature warming rate of 0.002˚C/year, the temperature increase was not. The number of low temperature days showed a significant downward trend, a decrease of 0.53 d/year, and in 1989 decreased mutation; the inter-annual temperature characteristics of four seasons showed warming, of which the highest temperature in autumn tendency, the smallest in winter. The correlation between mean temperature series is highest in spring and smallest in winter.

Changes in “hotter and wetter” events across China

As global warming intensifies, efforts to understand the changes in extreme climate events have increased in recent years. A combined analysis of the changes in extreme temperature and precipitation events is presented in this paper. Using observational data from 1961 to 2015, a set of hotter and wetter (HW) events is defined, and we examine the changes in these events across China. The results show that more HW events occur in Central and Eastern China than in other subregions, especially in South China (SC). The rate of increase in HW events is 2.7 and 1.9 per decade in SC and East China (EC), respectively. In China, most HW events occurred in the last 20 years of the study period, indicating that China entered a period of high-frequency HW events. Indeed, the range in anomalies in the torrential rain days is greater than that of the high-temperature days in Northwest China (NWC), Central China (CC), and EC after the mid- to late 1990s. The opposite pattern is found in Northeast China (NEC), Southwest China-region 1 (SWC1), Southwest China-region 2 (SWC2), and SC. Finally, the increase in HW events in most regions of China is closely associated with warming.

An alternative protocol to artificially simulate short-term ageing of binders for selected regional condition

This paper presents an alternative method for developing a laboratory short-term ageing procedure for binders that corresponds to the asphalt mixture production practices carried out in a tropical region. In this method, the ASTM D2872 procedure was adapted to artificially short-term age asphalt binders, while ageing time and ageing temperature were evaluated. A statistical technique named response surface method (RSM) was used for the design of experiment, analysis of the test results from the field and laboratory samples, and selection of an appropriate laboratory protocol. An experimental matrix was designed based on the central composite method for two basic independent laboratory factors: ageing times in a range of 85–175 min, and ageing temperatures within 148–178 °C. Several test variables, include softening point, penetration, G∗/sin δ at 64 °C and rotational viscosity at 135 °C of three conventional binders were considered as dependent test factors (responses). The responses were analyzed using RSM to derive mathematical equations, while the corresponding time and temperature were determined from optimization of the test results. The outcome of this study indicated that the conventional short-term ageing protocol in accordance with the ASTM D2872 may not be sufficient to simulate the short-term ageing of asphalt binders in the Malaysian weather condition, where high daily temperatures, humidity, and ultraviolet are concerned. Based on the statistical analyses, both time and temperature have significantly affect the physical and rheological properties of short-term aged binders. Overall, all three binders show quadratic models for the resulting responses with the exception of two binders which show 2FI and linear models for its physical properties. The resulting optimization recommends a short-term ageing procedure at 170 °C for 135 min to appropriately mimic the field binder properties under Malaysian climate.

Wheat Yield Affected by Soil Temperature and Water under Mulching in Dryland

Core Ideas Plastic mulch increased soil temperature and water, thus increased wheat yield. High soil temperature by plastic mulch and planting legume reduced wheat yield. Incorporation of legume increased soil temperature of next wheat growing season. Planting legume increased soil water use in summer and decreased evapotranspiration in wheat season. In the Loess Plateau of northwestern China, soil water shortage is the main factor constraining dryland wheat (Triticum aestivum L.) production. Soil mulching is considered an effective practice to improve wheat yield due to increased soil water storage, but the information related to integrated understanding of soil temperature and water is scarce. We conducted a location‐fixed field experiment with two soil mulching (plastic mulch and planting legume) treatments to confirm the effects of soil temperature and water on wheat yield under different precipitation levels. In 2014–2015 with higher than average precipitation, plastic mulch increased soil water storage by 13% at sowing and average soil temperature by 0.4°C, which in turn increased yield by 13%, compared to the control. In 2012–2013 with extremely lower than average precipitation, the high daily maximum soil temperature during wheat reproductive period decreased grain number per spike and grain weight by 16 and 4%, respectively, thus reduced yield by 16%. For planting legume, the lower soil water storage at sowing and high daily maximum soil temperature during the wheat reproductive period decreased the number of spikes per hectare and grain weight by 29 and 4%, respectively, resulting in a 37% decrease in yield in 2012–2013. In other years with relatively higher precipitation, the proper soil temperature and extra N input under planting legume alleviated the negative impact of yield decline. Overall, planting legume did not show any benefit for wheat yield, while plastic mulch provided an opportunity for increasing wheat yield in dryland.

Projecting temperature-related years of life lost under different climate change scenarios in one temperate megacity, China.

Temperature has been associated with population health, but few studies have projected the future temperature-related years of life lost attributable to climate change. To project future temperature-related disease burden in Tianjin, we selected years of life lost (YLL) as the dependent variable to explore YLL attributable to climate change. A generalized linear model (GLM) and distributed lag non-linear model were combined to assess the non-linear and delayed effects of temperature on the YLL of non-accidental mortality. Then, we calculated the YLL changes attributable to future climate scenarios in 2055 and 2090. The relationships of daily mean temperature with the YLL of non-accident mortality were basically U-shaped. Both the daily mean temperature increase on high-temperature days and its drop on low-temperature days caused an increase of YLL and non-accidental deaths. The temperature-related YLL will worsen if future climate change exceeds 2°C. In addition, the adverse effects of extreme temperature on YLL occurred more quickly than that of the overall temperature. The impact of low temperature was greater than that of high temperature. Men were vulnerable to high temperature compared with women. This analysis highlights that the government should formulate environmental policies to reach the Paris Agreement goal.

High day- and night-time temperatures affect grain growth dynamics in contrasting rice genotypes.

Rice grain yield and quality are predicted to be highly vulnerable to global warming. Five genotypes including heat-tolerant and susceptible checks, a heat-tolerant near-isogenic line and two hybrids were exposed to control (31 °C/23 °C, day/night), high night-time temperature (HNT; 31 °C/30 °C), high day-time temperature (HDT; 38 °C/23 °C) and high day- and night-time temperature (HNDT; 38 °C/30 °C) treatments for 20 consecutive days during the grain-filling stage. Grain-filling dynamics, starch metabolism enzymes, temporal starch accumulation patterns and the process of chalk formation were quantified. Compensation between the rate and duration of grain filling minimized the impact of HNT, but irreversible impacts on seed-set, grain filling and ultimately grain weight were recorded with HDT and HNDT. Scanning electron microscopy demonstrated irregular and smaller starch granule formation affecting amyloplast build-up with HDT and HNDT, while a quicker but normal amylopast build-up was recorded with HNT. Our findings revealed temporal variation in the starch metabolism enzymes in all three stress treatments. Changes in the enzymatic activity did not derail starch accumulation under HNT when assimilates were sufficiently available, while both sucrose supply and the conversion of sucrose into starch were affected by HDT and HNDT. The findings indicate differential mechanisms leading to high day and high night temperature stress-induced loss in yield and quality. Additional genetic improvement is needed to sustain rice productivity and quality under future climates.