Extreme Temperatures (extreme + temperature)

Distribution by Scientific Domains

Terms modified by Extreme Temperatures

  • extreme temperature event

  • Selected Abstracts


    Trends in daily precipitation and temperature extremes across western Germany in the second half of the 20th century

    INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 9 2005
    Yeshewatesfa Hundecha
    Abstract The evolution of daily extreme precipitation and temperature from 1958 to 2001 was investigated within the German side of the Rhine basin. Trends of a set of extreme precipitation and temperature indices defined on daily time series of precipitation and temperature were calculated at 611 precipitation and 232 temperature stations located within the study area and their corresponding significances were tested using the non-parametric Kendall- tau test. The results obtained indicated that both the daily minimum and maximum extreme temperatures have increased over the investigation period, with the degree of change showing seasonal variability. On an annual basis, the change in the daily minimum extreme temperature was found to be greater than that of the daily maximum extreme temperature. The daily extreme heavy precipitation has shown increasing trends both in magnitude and frequency of occurrence in all seasons except summer, where it showed the opposite trend. The station values of the daily precipitation were also interpolated on a regular grid of 5 km × 5 km so that the changes in the indices could be investigated on areal precipitation by aggregating the interpolated precipitation to any desired scale. This enables assessment of the hydrological consequences of the changes in the extreme precipitation. Although the spatial pattern remained more or less similar with that of the point-scale trends for all indices, the average trend magnitude showed an increase with the scale of the area on which precipitation was aggregated. Copyright © 2005 Royal Meteorological Society [source]


    Trends in extreme daily rainfall and temperature in Southeast Asia and the South Pacific: 1961,1998

    INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 3 2001
    M.J. Manton
    Abstract Trends in extreme daily temperature and rainfall have been analysed from 1961 to 1998 for Southeast Asia and the South Pacific. This 38-year period was chosen to optimize data availability across the region. Using high-quality data from 91 stations in 15 countries, significant increases were detected in the annual number of hot days and warm nights, with significant decreases in the annual number of cool days and cold nights. These trends in extreme temperatures showed considerable consistency across the region. Extreme rainfall trends were generally less spatially coherent than were those for extreme temperature. The number of rain days (with at least 2 mm of rain) has decreased significantly throughout Southeast Asia and the western and central South Pacific, but increased in the north of French Polynesia, in Fiji, and at some stations in Australia. The proportion of annual rainfall from extreme events has increased at a majority of stations. The frequency of extreme rainfall events has declined at most stations (but not significantly), although significant increases were detected in French Polynesia. Trends in the average intensity of the wettest rainfall events each year were generally weak and not significant. Copyright © 2001 Royal Meteorological Society [source]


    Environmental temperature stress on drugs in prehospital emergency medical service

    ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2003
    M. Helm
    Background: Drugs used in prehospital emergency medical service (EMS) in principle are subject to the same storage restrictions as hospital-based medications. The prehospital emergency environment however, often exceeds these storage recommendations. Main stress factors are sunlight, vibration and extreme temperature, which may lead to alteration in chemical and physical stability of stored pharmaceuticals, as well as microbiological contamination and concentration enhancement of pharmacological inserts. Methods: The purpose of this study was to determine the environmental temperature stress upon drugs used in the prehospital EMS under real mission conditions within different types of rescue vehicles (rescue helicopter [HEMS], ambulance [AMB] and emergency physician transport vehicle [EPTV]) during a ,summer' and ,winter' monitoring period (2 months duration each/location: southern Germany). Results: Recorded temperatures varied from ,13.2°C to +50.6°C. The recommended maximum storage temperature (+25°C) was exceeded in all rescue vehicles (33,45% of total exposure time), whereas the recommended minimum storage temperature (0°C) only fell short in the EPTV (19% of total exposure time). The daily maximum temperature variations ranged from 19.0°C (winter) to 32.9°C (summer). Conclusions: These results show that even in a moderate climatic zone, drugs used in prehospital EMS are significantly influenced by temperature stress; furthermore, these results recommend the usage of temperature-controlled drug boxes. [source]


    Extreme temperature 6H-SiC JFET integrated circuit technology

    PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 10 2009
    Philip G. Neudeck
    Abstract Extreme temperature semiconductor integrated circuits (ICs) are being developed for use in the hot sections of aircraft engines and other harsh-environment applications well above the 300 °C effective limit of silicon-on-insulator IC technology. This paper reviews progress by the NASA Glenn Research Center and Case Western Reserve University (CWRU) in the development of extreme temperature (up to 500 °C) integrated circuit technology based on epitaxial 6H-SiC junction field effect transistors (JFETs). Simple analog amplifier and digital logic gate ICs fabricated and packaged by NASA have now demonstrated thousands of hours of continuous 500 °C operation in oxidizing air atmosphere with minimal changes in relevant electrical parameters. Design, modeling, and characterization of transistors and circuits at temperatures from 24 °C to 500 °C are also described. CWRU designs for improved extreme temperature SiC JFET differential amplifier circuits are demonstrated. Areas for further technology maturation, needed prior to beneficial system insertion, are discussed. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Variation in thermal tolerance is linked to phosphoglucose isomerase genotype in a montane leaf beetle

    FUNCTIONAL ECOLOGY, Issue 2 2003
    G. Neargarder
    Summary 1Sierra Nevada populations of the Willow Beetle Chrysomela aeneicollis (Schaeffer) experience extreme elevated and subzero temperatures in nature. In these populations, frequencies of phosphoglucose isomerase (PGI) alleles vary with latitude and altitude and respond to climate change. PGI genotypes differ in expression of a stress-inducible heat shock protein (Hsp70). 2Here, differences in tolerance of elevated and subzero extreme temperatures were compared for field-acclimatized and laboratory-acclimated larvae and adults possessing three common PGI genotypes (PGI 1,1, 1,4 and 4,4). Three indices of thermal tolerance were measured , CTmax, LT50 and Hsp70 expression level. 3Thermal tolerance depended on life stage, prior exposure to sublethal stress and PGI genotype. Larvae were generally less tolerant of thermal extremes than adults. For both adults and larvae, prior exposure to sublethal temperatures increased survival after exposure to subsequent stress. Survival after exposure to thermal extremes was consistently related to PGI genotype (1,1 > 1,4 > 4,4), as were expression levels of Hsp70 (1,1 > 1,4 > 4,4). 4These results suggest that PGI genotypes differ in tolerance of thermal extremes routinely experienced by beetles in nature. A trade-off between thermal tolerance and energy allocation may explain the persistence of the PGI polymorphism. [source]


    Surface air temperature trends in Southern Brazil for 1960,2002

    INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 7 2008
    Jose A. Marengo
    Abstract Trends in minimum and maximum air temperature and in the diurnal thermal range (DTR), and derived indices of extreme temperatures since the 1960's are assessed for southern Brazil. Most meteorological stations show steep increases in the night-time temperatures (depicted by the minimum temperature) as compared to slight increases in the daytime temperature (depicted by the maximum temperature), both year round and at the seasonal level. The warming trends are stronger during winter as compared to summer. Consequently, the observed annual and seasonal negative DTR trends in southern Brazil during the last 40 years are largely due to the greater increase in nighttime temperatures rather than daytime temperatures. At decadal timescales, the presence of more intense and frequent El Niño events during the last 20 years also contributes to warming and explains the steep increase in the air temperature extremes trends during this period, as compared to the relatively colder 1960,1980 period, especially for winter. Indices of temperature extremes defined using fixed limits for maximum and minimum temperatures for colder or warmer days were compared with percentile-based indices defined in the recent literature. The comparison shows that the frequency of warmer days increased during both summer and winter, especially during the last two decades. The observed positive tendencies in minimum temperatures and warmer days during winter occur even though extreme cold events and freezing conditions occurred in 1975, 1994 and 2000. Copyright © 2007 Royal Meteorological Society [source]


    Change in mean temperature as a predictor of extreme temperature change in the Asia,Pacific region

    INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 10 2005
    G. M. Griffiths
    Abstract Trends (1961,2003) in daily maximum and minimum temperatures, extremes and variance were found to be spatially coherent across the Asia,Pacific region. The majority of stations exhibited significant trends: increases in mean maximum and mean minimum temperature, decreases in cold nights and cool days, and increases in warm nights. No station showed a significant increase in cold days or cold nights, but a few sites showed significant decreases in hot days and warm nights. Significant decreases were observed in both maximum and minimum temperature standard deviation in China, Korea and some stations in Japan (probably reflecting urbanization effects), but also for some Thailand and coastal Australian sites. The South Pacific convergence zone (SPCZ) region between Fiji and the Solomon Islands showed a significant increase in maximum temperature variability. Correlations between mean temperature and the frequency of extreme temperatures were strongest in the tropical Pacific Ocean from French Polynesia to Papua New Guinea, Malaysia, the Philippines, Thailand and southern Japan. Correlations were weaker at continental or higher latitude locations, which may partly reflect urbanization. For non-urban stations, the dominant distribution change for both maximum and minimum temperature involved a change in the mean, impacting on one or both extremes, with no change in standard deviation. This occurred from French Polynesia to Papua New Guinea (except for maximum temperature changes near the SPCZ), in Malaysia, the Philippines, and several outlying Japanese islands. For urbanized stations the dominant change was a change in the mean and variance, impacting on one or both extremes. This result was particularly evident for minimum temperature. The results presented here, for non-urban tropical and maritime locations in the Asia,Pacific region, support the hypothesis that changes in mean temperature may be used to predict changes in extreme temperatures. At urbanized or higher latitude locations, changes in variance should be incorporated. Copyright © 2005 Royal Meteorological Society. [source]


    Trends in daily precipitation and temperature extremes across western Germany in the second half of the 20th century

    INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 9 2005
    Yeshewatesfa Hundecha
    Abstract The evolution of daily extreme precipitation and temperature from 1958 to 2001 was investigated within the German side of the Rhine basin. Trends of a set of extreme precipitation and temperature indices defined on daily time series of precipitation and temperature were calculated at 611 precipitation and 232 temperature stations located within the study area and their corresponding significances were tested using the non-parametric Kendall- tau test. The results obtained indicated that both the daily minimum and maximum extreme temperatures have increased over the investigation period, with the degree of change showing seasonal variability. On an annual basis, the change in the daily minimum extreme temperature was found to be greater than that of the daily maximum extreme temperature. The daily extreme heavy precipitation has shown increasing trends both in magnitude and frequency of occurrence in all seasons except summer, where it showed the opposite trend. The station values of the daily precipitation were also interpolated on a regular grid of 5 km × 5 km so that the changes in the indices could be investigated on areal precipitation by aggregating the interpolated precipitation to any desired scale. This enables assessment of the hydrological consequences of the changes in the extreme precipitation. Although the spatial pattern remained more or less similar with that of the point-scale trends for all indices, the average trend magnitude showed an increase with the scale of the area on which precipitation was aggregated. Copyright © 2005 Royal Meteorological Society [source]


    Trends in extreme daily rainfall and temperature in Southeast Asia and the South Pacific: 1961,1998

    INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 3 2001
    M.J. Manton
    Abstract Trends in extreme daily temperature and rainfall have been analysed from 1961 to 1998 for Southeast Asia and the South Pacific. This 38-year period was chosen to optimize data availability across the region. Using high-quality data from 91 stations in 15 countries, significant increases were detected in the annual number of hot days and warm nights, with significant decreases in the annual number of cool days and cold nights. These trends in extreme temperatures showed considerable consistency across the region. Extreme rainfall trends were generally less spatially coherent than were those for extreme temperature. The number of rain days (with at least 2 mm of rain) has decreased significantly throughout Southeast Asia and the western and central South Pacific, but increased in the north of French Polynesia, in Fiji, and at some stations in Australia. The proportion of annual rainfall from extreme events has increased at a majority of stations. The frequency of extreme rainfall events has declined at most stations (but not significantly), although significant increases were detected in French Polynesia. Trends in the average intensity of the wettest rainfall events each year were generally weak and not significant. Copyright © 2001 Royal Meteorological Society [source]


    A grey-box model of next-day building thermal load prediction for energy-efficient control

    INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 15 2008
    Qiang Zhou
    Abstract Accurate building thermal load prediction is essential to many building energy control strategies. To get reliable prediction of the hourly building load of the next day, air temperature/relative humidity and solar radiation prediction modules are integrated with a grey-box model. The regressive solar radiation module predicts the solar radiation using the forecasted cloud amount, sky condition and extreme temperatures from on-line weather stations, while the forecasted sky condition is used to correct the cloud amount forecast. The temperature/relative humidity prediction module uses a dynamic grey model (GM), which is specialized in the grey system with incomplete information. Both weather prediction modules are integrated into a building thermal load model for the on-line prediction of the building thermal load in the next day. The validation of both weather prediction modules and the on-line building thermal load prediction model are presented. Copyright © 2008 John Wiley & Sons, Ltd. [source]


    Lifetime reproductive output of Calliphora vicina and Lucilia sericata in outdoor caged and field populations; flight vs. egg production?

    MEDICAL AND VETERINARY ENTOMOLOGY, Issue 4 2006
    LEWIS DAVIES
    Abstract Females of the blowflies Calliphora vicina (Robineau-Desvoidy) and Lucilia sericata (Meigen) (Diptera: Calliphoridae) maintained in sheltered outdoor cages and supplied with excess food, oviposited later than would have been expected from the temperature-sum. The survival rates of the caged flies was high and the isolation of flies from predation, extreme temperatures and food shortages is likely to have contributed to this. Despite good survival rates, subsequent egg production over the greater part of the adult life span was reduced to ,24% for C. vicina and ,55% for L. sericata, of the potential expected from the published temperature-sums required for the maturation of successive egg batches. The data suggest that under field-cage conditions there is a considerable variation in egg development between individuals of the same age and that this variation should not be overlooked, since it may have significant implications in ecological and forensic investigations; however, the cause of this variability remains unclear. While lower than expected, the reproductive outputs recorded in the cages were nevertheless considerably greater than those that have been estimated for blowflies in the field and illustrate the potential for population increase in these species under favourable conditions. The possibility of a greater energy investment in flight activity relative to reproductive output in C. vicina compared to L. sericata is proposed. [source]


    Cold adaptation in Arctic and Antarctic fungi

    NEW PHYTOLOGIST, Issue 2 2001
    Clare H. Robinson
    Summary Growth and activity at low temperatures and possible physiological and ecological mechanisms underlying survival of fungi isolated from the cold Arctic and Antarctic are reviewed here. Physiological mechanisms conferring cold tolerance in fungi are complex; they include increases in intracellular trehalose and polyol concentrations and unsaturated membrane lipids as well as secretion of antifreeze proteins and enzymes active at low temperatures. A combination of these mechanisms is necessary for the psychrotroph or psychrophile to function. Ecological mechanisms for survival might include cold avoidance; fungal spores may germinate annually in spring and summer, so avoiding the coldest months. Whether spores survive over winter or are dispersed from elsewhere is unknown. There are also few data on persistence of basidiomycete vs microfungal mycelia and on the relationship between low temperatures and the predominance of sterile mycelia in tundra soils. Acclimation of mycelia is a physiological adaptation to subzero temperatures; however, the extent to which this occurs in the natural environment is unclear. Melanin in dark septate hyphae, which predominate in polar soils, could protect hyphae from extreme temperatures and play a significant role in their persistence from year to year. [source]


    CO2 -concentrating mechanisms in Egeria densa, a submersed aquatic plant

    PHYSIOLOGIA PLANTARUM, Issue 4 2002
    María V. Lara
    Egeria densa is an aquatic higher plant which has developed different mechanisms to deal with photosynthesis under conditions of low CO2 availability. On the one hand it shows leaf pH-polarity, which has been proposed to be used for bicarbonate utilization. In this way, at high light intensities and low dissolved carbon concentration, this species generates a low pH at the adaxial leaf surface. This acidification shifts the equilibrium HCO3,/CO2 towards CO2, which enters the cell by passive diffusion. By this means, E. densa increases the concentration of CO2 available for photosynthesis inside the cells, when this gas is limiting. On the other hand, under stress conditions resulting from high temperature and high light intensities, it shows a biochemical adaptation with the induction of a C4 -like mechanism but without Kranz anatomy. Transfer from low to high temperature and light conditions induces increased levels of phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) and NADP-malic enzyme (NADP-ME, EC 1.1.1.40), both key enzymes participating in the Hatch-Slack cycle in plants with C4 metabolism. Moreover, one PEPC isoform, whose synthesis is induced by high temperature and light, is phosphorylated in the light, and changes in kinetic and regulatory properties are correlated with changes in the phosphorylation state of this enzyme. In the present review, we describe these two processes in this submersed angiosperm that appear to help it perform photosynthesis under conditions of extreme temperatures and high light intensities. [source]


    A Multivariate Contextual Analysis of Torture and Cruel, Inhuman, and Degrading Treatments: Implications for an Evidence-Based Definition of Torture

    AMERICAN JOURNAL OF ORTHOPSYCHIATRY, Issue 2 2009
    Metin Ba, lu MD
    Current thinking on what constitutes torture in a detention/interrogation setting focuses solely on particular procedures, without regard for contextual factors that mediate traumatic stress. The present study examined stressor interactions that determined severity and psychological impact of captivity stressors in 432 torture survivors in former Yugoslavia countries and Turkey. A principal components analysis of 46 captivity stressors measured by an Exposure to Torture Scale identified meaningful stressor clusters, which suggested that multiple detention procedures were used in combination to maximize their impact. Perceived torture severity related to ,cruel, inhuman, and degrading' treatments (CIDT) but not to physical torture. Posttraumatic stress disorder related to war-related captivity, deprivation of basic needs, sexual torture, and exposure to extreme temperatures, isolation, and forced stress positions but not to physical torture. CIDT increased posttraumatic stress disorder risk by 71%. Fear- and helplessness-inducing effects of captivity and CIDT appear to be the major determinants of perceived severity of torture and psychological damage in detainees. Considerations on what constitutes torture need to take into account the contextual processes in a captivity setting that mediate these effects. [source]


    Abiotic stress and plant responses from the whole vine to the genes

    AUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 2010
    G.R. CRAMER
    Abstract Drought, salinity and extreme temperatures significantly limit the distribution of grapes around the world. In this review, the literature of grape responses to abiotic stress with particular reference to whole plant and molecular responses observed in recent studies is discussed. A number of short-term and long-term studies on grapevine shoots and berries have been conducted using a systems biology approach. Transcripts, proteins and metabolites were profiled. Water deficit, salinity and chilling altered the steady-state abundance of a large number of transcripts. Common responses to these stresses included changes in hormone metabolism, particularly abscisic acid (ABA), photosynthesis, growth, transcription, protein synthesis, signalling and cellular defences. Some of the transcriptional changes induced by stress were confirmed by proteomic and metabolomic analyses. More than 2000 genes were identified whose transcript abundance was altered by both water deficit and ABA. Different gene sets were used to map molecular pathways regulated by ABA, water deficit, salinity and chilling in grapevine. This work supports the hypothesis that ABA is a central regulator of abiotic stress tolerance mechanisms. ABA affects signalling pathways that trigger important molecular activities involving metabolism, transcription, protein synthesis, and cellular defence and also regulates important physiological responses such as stomatal conductance, photoprotection and growth. Systems biology approaches are providing more comprehensive understanding of the complex plant responses to abiotic stress. The molecular sets generated from mapping the ABA-inducible stress responses provide numerous targets for genetic and cultural manipulation for improved plant protection and grape quality. [source]


    Ydj1 but not Sis1 stabilizes Hsp70 protein under prolonged stress in vitro

    BIOPOLYMERS, Issue 3 2008
    Lütfi Tutar
    Abstract Yeast cytosol has two important co-chaperons; Ydj1 and Sis1. Genetic experiments showed that Ydj1 is not essential for viability; however, cells lacking it grow very poorly at 30°C or unable to grow at extreme temperatures. On the other hand, Sis1 is an essential protein and apparently plays a functional role at assembly or disassembly of protein complexes. Stability experiments revealed that only Ydj1-protected Hsp70 proteins can hydrolyze ATP under prolonged stress. © 2007 Wiley Periodicals, Inc. Biopolymers 89: 171,174, 2008. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source]