Variation in adult stress resistance does not explain vulnerability to climate change in copper butterflies

Ongoing climate change is a major threat to biodiversity. However, although many species clearly suffer from ongoing climate change, others benefit from it, for example, by showing range expansions. However, which specific features determine a species’ vulnerability to climate change? Phenotypic plasticity, which has been described as the first line of defence against environmental change, may be of utmost importance here. Against this background, we here compare plasticity in stress tolerance in 3 copper butterfly species, which differ arguably in their vulnerability to climate change. Specifically, we investigated heat, cold and desiccation resistance after acclimatization to different temperatures in the adult stage. We demonstrate that acclimation at a higher temperature increased heat but decreased cold tolerance and desiccation resistance. Contrary to our predictions, species did not show pronounced variation in stress resistance, though plastic capacities in temperature stress resistance did vary across species. Overall, our results seemed to reflect population—rather than species‐specific patterns. We conclude that the geographical origin of the populations used should be considered even in comparative studies. However, our results suggest that, in the 3 species studied here, vulnerability to climate change is not in the first place determined by stress resistance in the adult stage. As entomological studies focus all too often on adults only, we argue that more research effort should be dedicated to other developmental stages when trying to understand insect responses to environmental change.     

Solar Absorber Gel: Localized Macro‐Nano Heat Channeling for Efficient Plasmonic Au Nanoflowers Photothermic Vaporization and Triboelectric Generation

Plasmonic nanoparticles with outstanding photothermal conversion efficiency are promising for solar vaporization. However, the high cost and the required intense light excitation of noble metals, hinder their practical application. Herein, an inexpensive 3D plasmonic solar absorber gel that embraces all the desirable optical, thermal, and wetting properties for efficient solar vaporization is reported. The broadband absorption and strong near‐field intertip enhancement of the sparsely dispersed gold nanoflowers contribute to efficient light‐to‐heat conversion, while the macro‐nano thermal insulative silica gel retains and channels the plasmonic heat directly to the water pathways contained within the porous gel. The plasmonic‐based solar absorber gel shows a vaporization efficiency of 85% under solar irradiation of 1 sun intensity (1 kW m^?2). Moreover, the porous gel framework exhibits high mechanical stability and antifouling properties, potentially useful for polluted/turbid water evaporation. Complementary water condensation‐induced triboelectricity can be harvested alongside fresh water condensate, granting simultaneous fresh water production and electricity generation functionalities. The facile sol‐gel synthesis at room temperature makes the solar absorber gel highly adaptable for practical large‐scale photothermal applications.     

Skin‐Inspired Low‐Grade Heat Energy Harvesting Using Directed Ionic Flow through Conical Nanochannels

Low‐grade heat energies are ubiquitous, and most of these energies are untapped as heated river water or seawater. Therefore, it is meaningful and valuable to extract the stored energies in the context of the energy crisis by using a simple device with low‐cost effectiveness. Here, a simple thermoelectric conversion system is shown using directed ionic flow through the biomimetic smart nanochannels, inspired by the human skin. The obtained power density of the nanodevice can ideally be 88.8 W m^?2 with a membrane temperature gradient (ΔT) of 40 °C. As proof of concept, it is demonstrated that the principle can be introduced into simple and portable prototypes to harvest low‐grade heat. Such a thermoelectric conversion apparatus provides a new venue for low‐grade heat harvesting. In addition, this self‐powered system may extend the electronic skin field and find applications in skin prosthetics.     

Behavioral and hematological responses of broiler chickens administered with betaine and ascorbic acid during hot-dry season

Heat stress is a major problem in poultry production in tropical regions. Assessing the impact of thermally stressful environmental conditions on the welfare of broiler chickens is of great importance. Behavioral responses in a novel environment and hematology of broiler chickens administered with betaine and/or ascorbic acid (AA) during the hot-dry season were evaluated. Broiler chickens were randomly divided into four groups: Group I (control) was given sterile water, Group II was given betaine, Group III was given AA, and Group IV received betaine + AA orally and daily for 42 days. An open-field test was used to assess behavior. Hematological parameters were obtained using a hematology auto-analyzer. The natural environmental conditions were predominantly outside the thermoneutral zone for broiler chickens. Results demonstrated that treated groups exhibited improved ability to adjust faster to a new environment and better hematological responses than controls, evidenced by enhanced behavioral responses, oxygen-carrying capacity, and immune responses of broiler chickens under unfavorable environmental conditions. Betaine and/or AA administration to broiler chickens improved some behavioral responses, hemoglobin concentrations, packed cell volume, and total leukocyte count during the hot-dry season.     

Impacts of climate change on rice production in Africa and causes of simulated yield changes

This study is the first of its kind to quantify possible effects of climate change on rice production in Africa. We simulated impacts on rice in irrigated systems (dry season and wet season) and rainfed systems (upland and lowland). We simulated the use of rice varieties with a higher temperature sum as adaptation option. We simulated rice yields for 4 RCP climate change scenarios and identified causes of yield declines. Without adaptation, shortening of the growing period due to higher temperatures had a negative impact on yields (?24% in RCP 8.5 in 2070 compared with the baseline year 2000). With varieties that have a high temperature sum, the length of the growing period would remain the same as under the baseline conditions. With this adaptation option rainfed rice yields would increase slightly (+8%) but they remain subject to water availability constraints. Irrigated rice yields in East Africa would increase (+25%) due to more favourable temperatures and due to CO2 fertilization. Wet season irrigated rice yields in West Africa were projected to change by ?21% or +7% (without/with adaptation). Without adaptation irrigated rice yields in West Africa in the dry season would decrease by ?45% with adaptation they would decrease significantly less (?15%). The main cause of this decline was reduced photosynthesis at extremely high temperatures. Simulated heat sterility hardly increased and was not found a major cause for yield decline. The implications for these findings are as follows. For East Africa to benefit from climate change, improved water and nutrient management will be needed to benefit fully from the more favourable temperatures and increased CO2 concentrations. For West Africa, more research is needed on photosynthesis processes at extreme temperatures and on adaptation options such as shifting sowing dates.     

Engineering heat tolerance in potato by temperature‐dependent expression of a specific allele of HEAT‐SHOCK COGNATE 70

For many commercial potato cultivars, tuber yield is optimal at average daytime temperatures in the range of 14–22 °C. Further rises in ambient temperature can reduce or completely inhibit potato tuber production, with damaging consequences for both producer and consumer. The aim of this study was to use a genetic screen based on a model tuberization assay to identify quantitative trait loci (QTL) associated with enhanced tuber yield. A candidate gene encoding HSc70 was identified within one of the three QTL intervals associated with elevated yield in a Phureja–Tuberosum hybrid diploid potato population (06H1). A particular HSc70 allelic variant was linked to elevated yield in the 06H1 progeny. Expression of this allelic variant was much higher than other alleles, particularly on exposure to moderately elevated temperature. Transient expression of this allele in Nicotiana benthamiana resulted in significantly enhanced tolerance to elevated temperature. An TA repeat element was present in the promoter of this allele, but not in other HSc70 alleles identified in the population. Expression of the HSc70 allelic variant under its native promoter in the potato cultivar Desiree resulted in enhanced HSc70 expression at elevated temperature. This was reflected in greater tolerance to heat stress as determined by improved yield under moderately elevated temperature in a model nodal cutting tuberization system and in plants grown from stem cuttings. Our results identify HSc70 expression level as a significant factor influencing yield stability under moderately elevated temperature and identify specific allelic variants of HSc70 for the induction of thermotolerance via conventional introgression or molecular breeding approaches.     

姜黄素预处理对沙漠干热环境中暑大鼠心肌细胞凋亡和Caspase-3活性的影响

目的:研究姜黄素预处理对沙漠干热环境不同阶段中暑大鼠心肌损伤、细胞凋亡及半胱天冬氨酸蛋白酶-3(Caspase-3)活性的影响。方法:选择雄性健康SD大鼠80只,将其随机分为2组(n=40):盐水对照组以及姜黄素预处理组。每组再分为4个亚组(n=10):干热0 min组(即常温组),干热50 min组(轻度中暑组),干热100 min组(中度中暑组),干热150 min组(重度中暑组)。盐水组大鼠给予0.9%生理盐水灌胃,姜黄素组大鼠给予剂量为100 mg/kg姜黄素灌胃,各组大鼠均连续灌胃7天。0 min组置于常温环境中,其余组放置在西北特殊环境人工实验舱内,设置干热环境:温度(41±0.5)℃,湿度(10±1)%,并在相应时间点麻醉大鼠,取血液以及心脏组织。检测血液心肌酶谱磷酸肌酸激酶(CK)、磷酸肌酸激酶同工酶(CK-MB)及乳酸脱氢酶(LDH)水平,用TUNEL法检测心肌细胞凋亡率,Caspase-3比色试剂盒检测Caspase-3活性。结果:随着干热环境时间的延长,大鼠血清CK、CK-MB、LDH水平、心肌细胞凋亡率及心肌组织Caspase-3活性均逐渐升高,而姜黄素预处理组在干热环境放置50 min、100 min和150 min时的血清CK、CK-MB、LDH水平、心肌细胞凋亡率及心肌组织Caspase-3活性均明显低于对照组(P0.01)。结论:姜黄素预处理可通过减少心肌细胞凋亡、增加Caspase-3活性,保护沙漠干热环境中暑大鼠心肌损伤。