• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 119
  • 104
  • 36
  • 11
  • 3
  • 2
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 371
  • 371
  • 83
  • 41
  • 40
  • 33
  • 31
  • 25
  • 24
  • 24
  • 23
  • 22
  • 22
  • 20
  • 19
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
301

Prostorové vzory vazeb mezi teplotními extrémy a úmrtností na kardiovaskulární nemoci v ČR / Spatial patterns of links between temperature extremes and cardiovascular mortality in the Czech Republic

Urban, Aleš January 2016 (has links)
Name of the thesis: Spatial patterns of links between temperature extremes and cardiovascular mortality in the Czech Republic Author: Mgr. Aleš Urban Previous studies have examined relationships of high and low air temperatures to mortality due to cardiovascular diseases (CVDs) in the Czech Republic as a whole. Much less has been understood about possible regional differences in the heat and cold effects on mortality. Within four papers published in international peer-reviewed journals, the author of this thesis investigated links between extreme temperatures and CVD mortality in the Czech Republic while considering in particular differences between (i) urban and rural areas, (ii) regions with different socioeconomic status, and (iii) regions with different physical-environmental conditions. Various biometeorological approaches were compared in order to identify meteorological characteristics affecting heat- and cold-related mortality. Excess mortality was determined as differences between observed and expected daily values, the latter being adjusted for long-term changes, annual and weekly cycles, and epidemics of influenza/acute respiratory infections. Air temperature, biometeorological indices (including the Universal Thermal Climate Index, Apparent Temperature, and Physiologically Equivalent...
302

Identification and Characterisation of Lipid Droplet-Localised Proteins

Krawczyk, Hannah Elisa 12 January 2022 (has links)
No description available.
303

THREE ESSAYS ASSESSING THE ECONOMIC IMPLICATIONS OF HEAT STRESS IN LABOR

Wajiha Saeed (12530830) 13 May 2022 (has links)
<p>  </p> <p>This dissertation assesses three aspects of the economic implications of heat stress-related labor-capacity losses. Given that low-income countries around the tropics are at most risk, our analyses focus on these and the vulnerable households within them. First, we consider the optimal allocation of labor for small-scale agricultural households. We build an agricultural household that takes into consideration that these households will be affected by heat stress as producers, consumers, and workers simultaneously. Using this model and a sample of households from Pakistan, we determine that for most households it would be optimal to increase their supply of family labor to agricultural self-employment. However, if work preferences are also affected, even modestly, then decreased supply of family labor to agriculture would be observed. </p> <p>Next, we turn to country-level welfare losses across the globe focusing on the role of trade in mitigating or exacerbating these. We consider nine West African economies and determine which benefit from international trade, which are made worse-off, and we fully delineate the factors and channels that determine this. Broadly, we find that net exporters of agricultural commodities will benefit via global price changes, and conversely net importers will be made worse off by global price changes. However, countries that experience especially large labor capacity losses in their export sectors can also see loss-mitigating effects from trade as their export prices rise more sharply that the global average. An alternative perspective shows that some countries are affected more by their own heat stress-related productivity losses, while others are affected more due to global changes. </p> <p>Lastly, we consider the poverty impacts of heat stress-induced labor capacity losses in West Africa. Using a macro model, we determine changes in real incomes of households near poverty in seven West African countries, then use household microsimulations to determine poverty impacts. We find that poverty impacts are heterogenous in direction and magnitude across household-types and countries. In five of the seven countries, poverty headcounts increase, ranging from 1.5% in Cote d’Ivoire to 7.8% in Nigeria. In two countries, there is either little change or a decrease in poverty: in Cameroon poverty increases by 0.6% and in Guinea it decreases by 1.7%. The key channel behind this heterogeneity is how loss of labor productivity affects relative returns to factors of production. Returns to unskilled agricultural labor can increase due to increased demand for this labor to dampen losses of agricultural output. </p>
304

Co-Benefits of Global and Domestic Greenhouse Gas Emissions for Air Quality and Human Health

Jason West, J., Zhang, Yuqiang, Smith, Steven J., Silva, Raquel A., Bowden, Jared H., Naik, Vaishali, Li, Ying, Gilfillan, Dennis, Adelman, Zachariah, Fry, Meridith M., Anenberg, Susan C., Horowitz, Larry, Lamarque, Jean Francois 01 January 2017 (has links)
Most co-benefits studies have been conducted on local or national scales. However, we find that for a coordinated international GHG reduction, much of the air quality and health benefits come from GHG reductions in foreign nations. This is particularly true for ozone, which has a longer atmospheric lifetime than PM2.5, and which is affected by methane reductions. Together these findings show that co-benefits for air quality and health are greater when GHG reductions are coordinated with other nations. These results also show that previous co-benefits studies on local or national scale may significantly underestimate the total co-benefits by omitting i.) the benefits of domestic pollutant reductions for regions outside of the domain considered, and ii.) the benefits of foreign GHG reductions if the domestic reduction is coordinated with international action.
305

Thermo and drought tolerance markers and regulation of heat stress proteins for chickpea (Cicer arietinum L.; Fabaceae) production in NE South Africa

Makonya, Givemore Munashe 19 November 2020 (has links)
Chickpea (Cicer arietinum) is an important legume crop globally ranked third after dry bean (Phaseolus vulgaris) and field pea (Pisum sativum). It constitutes 20% of the total global pulse production and around 95% of its production and consumption takes place in developing countries. Major constraints to chickpea production in sub Saharan Africa (SSA) have broadly been related to abiotic stresses, particularly drought and heat stresses, predicted to increase due to the global climatic changes.Dueto the imperativeness of research for identifying heat tolerance markers for potential chickpea genotype selection, in chapter two of the thesis, the response of four chickpea genotypes to a natural temperature gradient in the field was assessed using chlorophyll fluorescence, non-structural carbohydrate, gas exchange and grain yield. Field experiments were carried out in two winter seasons at three locations with known differences in temperature in NE South Africa. Results showed two genotypes (Acc#3 and Acc#7) were tolerant to heat stress with an Fᵥ/Fₘ of 0.83-0.85 at the warmer site, while the two sensitive genotypes (Acc#RR-2 and Acc#8) showed lower Fᵥ/Fₘ of 0.78-0.80. Both chlorophyll fluorescence measurements: dark-adapted Fᵥ/Fₘ and Fq'/Fₘ' (where Fq' =Fₘ'–F) measured at comparable high light levels correlated positively with grain yield. The two tolerant genotypes also showed higher photosynthetic rates,starch, sucrose and grain yield than the sensitive genotypes at the warmer site. However, these parameters were consistently higher at the cooler than at the warmer sites. It was concluded that genotypes Acc#RR-3 and Acc#7 are heat tolerant and chlorophyll fluorescence and leaf carbohydrates are suitable tools for selection of heat tolerant chickpea genotypes under field conditions. The coolest site of Polokwane showed favourable conditions for chickpea production.Heat and drought stresses are two abioticfactors that often occur simultaneously and are predicted to increase, consequently hampering plant growth. Response of different species to either stresses is well documented but information on the response of the same genotypes to both stresses in chickpea is limited. We aimed to determine whether previously noted heat stress tolerant genotype (Acc#7) is drought tolerant and the heat sensitive (Acc#8) is drought sensitive, and whether intermittent moisture supply at vegetative stage would induce priming effect to later drought at flowering. At vegetative stage, plants were divided into three groups, non-stressed (watered to 75% field capacity (FC), severe water stress (moisture-withholding for 14 days) and treated to 40% FC throughout the experiment (mild-stress), with recovery for the severely stressed plants after which they were stressed (double-stress) at flowering. Drought treatments at vegetative and flowering growth stages decreased physiological parameters and biomass accumulation in both genotypesexcept low water supply at 40% FC that decreased biomass in Acc#7 but not Acc#8. Double drought stress resulted in priming effect in Acc#7, having higher biomass, chlorophyll fluorescence, stomatal conductance, net photosynthesis, and relative water content in comparison to the introduction of stress only at flowering growth stage, as well as in comparison to Acc#8. These results showed that both Acc#7 and Acc#8 are sensitive to drought whereas after priming Acc#7 is better acclimated to drought than Acc#8 associated with osmotic adjustment on leaf relative water content (RWC) and higher capacity to protect photosynthetic activity, making Acc#7 potentially ideal for areas associated with intermittent drought spells. This observation, however, disapproved the hypothesis that Acc#7 is more drought tolerant than Acc#8 but is rather better acclimated than Acc#8, because of its superiority only in primed plants and not those stressed only at either vegetative or flowering stages. The findings emphasise the importance of matching chickpea physiological performance to expected rainfall amounts and distribution in drought prone areas during genotype selection. Chapter four of the thesis was an interrogative proteome analysis of the differences in the heat tolerant and sensitive chickpea (Cicer arietinumL.; Fabaceae) genotypes along a temperature gradient under field conditions which will help in identifying the molecular mechanisms involved in the crop's tolerance. Few studies have thus far combined chickpea physiological and proteome analysis to elucidate the changes in abundance and/or activity of relevant enzymes and expression of heat responsive proteins. In this study, analyses of chlorophyll concentrations, gas exchange, flavonoids and anthocyanin concentrations from a chamber experiment, as well as proteomic parameters from field studies in both the heat tolerant and sensitive genotypes are presented. The heat tolerant genotype Acc#7 maintained unaltered physiological performance at flowering growth stage when exposed to high (35/30°C) and moderate (30/25°C) heat stress, under climate chamber conditions compared to the two heat susceptible genotypes (Acc#RR-2 and Acc#8). Results from the proteomic studies showed an up-regulation in proteins related to protein synthesis (e.g. ribulose bisphosphate carboxylase/oxygenase activase), intracellular traffic (e.g. mitochondrial dicarboxylate/tricarboxylate transporter DTC), defence (e.g. HSP70) and transport (e.g. GTP-binding protein SAR1A-like) in heat tolerant Acc#7 compared to the susceptible Acc#8. Results from KEGG analyses support the involvement of probable sucrose-phosphate synthase and sucrose-phosphate phosphatase proteins in the starch and sucrose pathway,that were up-regulated in the heat tolerant genotype Acc#7. This result was in support of our earlier report where tolerant genotype Acc#7 had higher leaf starch and sucrose concentrations in comparison to the susceptible genotype Acc#8. The presence of these differentially regulated proteins including HSP70, ribulose bisphosphate carboxylase/oxygenase activase, plastocyanin and protoporphyrinogen oxidase shows their potential role in field grown chickpea tolerance to heat stress at flowering growth stage. In conclusion, chlorophyll fluorescence (both Fᵥ/Fₘ and Fq'/Fₘ') and leaf carbohydrates were identified as selection markers that can potentially be used for chickpea phenotyping for heat stress under field conditions with the chlorophyll fluorescence parameters correlating positively with seed yield. Due to its higher biomass, chlorophyll fluorescence (Fᵥ/Fₘ), stomatal conductance, net photosynthesis and RWC, heat tolerant genotype Acc#7 was identified to have better adaptive tolerance to drought stress after priming through exposure to intermittent dry spells than Acc#8. Furthermore, under controlled climate chamber conditions, Acc#7 consistently showed characteristics of tolerance to heat stress while Acc#RR-2 and Acc#8 were heat susceptible. Higher chlorophyll fluorescence, grain yield, chlorophyll concentrations, gas exchange, flavonoids and anthocyanin concentrations for Acc#7 compared to Acc#8 in the climate chamber was further validated by the higher up-regulation of proteins involved in protein synthesis, intracellular traffic, defence and transport in Acc#7 compared to Acc#8. The incorporation of proteomics in heat and drought stress studies will potentially help further the understanding of mechanisms by which the crop responds to these stresses.
306

Effects of acute heat stress on glucose metabolism and 5' adenosine monophosphate-activated protein kinase in skeletal muscle / 急性的な熱刺激が骨格筋糖代謝とAMPキナーゼに及ぼす影響

Goto, Ayumi 23 March 2016 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(人間・環境学) / 甲第19806号 / 人博第777号 / 新制||人||187(附属図書館) / 27||人博||777(吉田南総合図書館) / 32842 / 京都大学大学院人間・環境学研究科共生人間学専攻 / (主査)教授 林 達也, 教授 森谷 敏夫, 教授 石原 昭彦 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DGAM
307

Physiological Responses to Heat-stress in a Desert Montane Lizard

Vazquez, Tyara Kiileialohalani January 2018 (has links)
No description available.
308

Heat Stress Inhibits Chloroplast Development in Ivy Geranium

Horton, Anna McLaurin 04 May 2018 (has links)
Pelargonium peltatum, ivy geranium, experiences foliar bleaching at temperatures exceeding 30° C. Contessa™ Red (heat tolerant) and Temprano™ Lavender (heat susceptible) were compared. Established plants underwent temperature treatments of 15/20° C or 25/30° C night/day with moisture treatments of 80% or 30% substrate volumetric water content (VWC). Photosynthesis, leaf greenness and growth data were collected at days 0, 7 and 11. No differences in photosynthetic rate nor a decrease in greenness in developed leaves occured in either cultivar due to high temperature or drought. Contessa™ Red had overall greater growth and leaf greenness than Temprano™ Lavender. Greenness and growth increased similarly for both cultivars at 80% VWC. Any decrease in foliar bleaching due to drought was likely due to a decrease in growth. A second study using Temprano™ Lavender indicated foliar bleaching occurs in newly emerging, developing leaves.
309

Evaluation of heat abatement use, vaginal temperature, and activity of pregnant, lactating Holstein cows housed on pasture with or without the choice between shade and sprinklers for heat abatement.

Braman, Kevin M. 08 August 2023 (has links) (PDF)
The objective of this thesis was to determine how pregnant, lactating Holstein cows on pasture interact with shade and sprinklers when offered a choice or no-choice between methods. Authors hypothesized that cows would use shade more then sprinklers, but sprinklers would be more effective at cooling cows. Additionally, authors predicted cows using shade more would have decreased lying bouts and steps and an increase in time lying, compared to cows choosing sprinkler. Results indicate cows will use both methods when offered alone or together. However, cows will choose to be exposed or in shade at lower temperature humidity index values, but as the heat load increases, cows will shift to using sprinkler just as much as shade, and decrease overall time exposed. Overall, sprinklers were more effective at reducing vaginal temperature in heat stressed cows on pasture. Cows in shade had decreased lying bouts and steps, and increased time lying.
310

Evaporative cooling strategies in urban areas: The potential of vertical greening systems to reduce nocturnal heat stress

Görgen, Fabian, Rossi-Schwarzenbeck, Monica 08 June 2023 (has links)
This research is part of a project that aims to create a simulation workflow to design adaptive facades to not only reduce the energy demand of buildings and provide a good level of indoor comfort, but also to mitigate the urban heat island effect. The anthropogenic climate change results in a steady increase of hot days, tropical nights and heavy rainfall, affecting the quality of human comfort, especially in urban areas not only in hot regions of the world but also in Central Europe. Vertical greening systems are often a first-choice mitigation strategy to im- prove the deteriorating situation. By combining the use of natural resources like rainwater and solar radiation, the greening evaporates water and provides natural cooling. This paper deals with the efficiency and feasibility of vertical greening systems towards a relief in heat stress by sim- ulating different constructions under local circumstances of three climate zones, focusing on the night-time. To carry out the simulations with microclimate simulation tool ENVI-met, an urban apartment complex was designed and provided with different kinds of vertical greening to in- vestigate the various positive effects resulting from the green façade. As a shading device, the greened walls showed a significant decrease of wall surface temperatures of up to 18K. However, restricted transpiration fluxes obstruct exploiting the full potential of evaporative cooling, espe- cially during night-time.

Page generated in 0.0346 seconds