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Cool
Terms modified by Cool Selected AbstractsFREQUENCY OF SALMONELLA, CAMPYLOBACTER, LISTERIA AND ENTEROBACTERIACEAE DETECTION IN COMMERCIALLY COOL WATER-WASHED SHELL EGGSJOURNAL OF FOOD SAFETY, Issue 4 2006DEANA R. JONES ABSTRACT The effect of cool water washing on shell egg temperature and pathogen detection was examined. Three temperature schemes were utilized in commercial dual washer systems: (1) HH = 48.9C, 48.9C; (2) HC = 48.9C, 23.9C; and (3) CC = 23.9C, 23.9C. HH eggsmaintainedthe highest surface temperature (26.25C in-line, 20.25C off-line and 23.25C combined, P < 0.05). The lowest temperatures were found in the CC eggs (21.25C in-line, 17.25C off-line and 19.25C combined). The frequency of Enterobacteriaceae detection in shell and membrane emulsions was greatest for the CC eggs (P < 0.05 for in-line and combined). There was no difference in Enterobacteriaceae detection for the off-line facility. Salmonella was detected in three of 384 samples from the in-line facility. They were found in HC (2) and CC (1) shell emulsions. Two of 384 samples were positive for Campylobacter from the in-line facility (CC). Three wash water samples were positive for Listeria in the off-line facility (1 HC, 2 CC). No pathogens were detected in the egg contents during this study. The results of this study indicate that warm followed by cool water washing has the potential of decreasing egg temperature while maintaining surface microbiology at an acceptable level. [source] An analysis of the concept of cool and its marketing implicationsJOURNAL OF CONSUMER BEHAVIOUR, Issue 4 2002Professor Clive Nancarrow Abstract Cool has become the favoured language of popular culture. This paper examines the roots of cool and its evolution with reference to its relevance to marketers. In particular, the work of Bourdieu and the concepts of cultural capital and cultural intermediaries are drawn on. The importance of talking to cultural intermediaries led Seagram to carry out a research programme that examines the process of adoption of alcoholic drinks and ways of reaching ,style leaders'. Given the problem of recruiting and researching ,style leaders', the research employed specialist recruiters and moderators and a combination of direct and indirect questioning. Copyright © 2002 Henry Stewart Publications. [source] Wittgenstein's Temple: Or How Cool Is Philosophy?PHILOSOPHICAL INVESTIGATIONS, Issue 1 2007Michael McGhee How should we understand Wittgenstein's comment in 1929 that his ,ideal' was ,a certain coolness'? Does it have the implication for the practice of philosophy that is suggested by the late Dewi Phillips? Wittgenstein's use of the metaphor of a temple in relation to the passions is curiously reminiscent in its structure of Rilke's first sonnet to Orpheus. In Zettel a similar preoccupation seems to be manifested in the long and unexpected passage that Wittgenstein copies out from Plato, a passage which is juxtaposed to the famous remark that the philosopher is the citizen of no community of ideas. [source] Information behavior in developing countries: Research, issues, and emerging trendsPROCEEDINGS OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE & TECHNOLOGY (ELECTRONIC), Issue 1 2007Dania Bilal Moderator The field of library and information science (LIS) has historically been a leading discipline in studying human information behavior (Spink & Cole, 2006). Information seeking in industrialized nations is grounded in theories and moving towards new directions and evolutionary approaches that often challenge the established paradigms of information behavior studies (see Case, 2007; Spink & Cole, 2006; Fisher, Erdelez, & Mckechnie, 2005; Chelton & Cool, 2004. Information behavior has been conceptualized in a holistic context that draws upon theories from various disciplines such as cognitive science, communication, psychology, and computer science (Nahl & Bilal, 2007; Spink & Cole, 2006). Compared to industrialized nations, most developing countries relegate towards the bottom heap of research on information behavior (Coleman, 2005; Britz, 2005). A panel of researchers, educators, and consultants will address research in information behavior in various contexts in developing countries, particularly in India, South Africa, and the Arab world. Based on their research findings and experiences, the speakers will trace themes, map the intellectual terrain, identify emerging trends and approaches, and frame issues related to information behavior research in these countries. Moreover, they will identify significant knowledge domains, concepts, and topics of application in information behavior research where there can be mutual exchange between developing countries and the industrialized nations (including the United States) to nurture and further growth in this area of study. [source] Arab American Adolescent Perceptions and Experiences with SmokingPUBLIC HEALTH NURSING, Issue 3 2003Anahid Kulwicki R.N., D.N.S. Abstract The purpose of this pilot study was to gather information on Arab American adolescent tobacco use behavior. This information was used to modify the Project Toward No Tobacco Use cessation program so that it would reflect the cultural values of Arab American youths. Focus group interviews were conducted to collect qualitative data from 28 Arab American adolescents between the ages of 14 and 18 years. The number of participants in the focus groups ranged from three to eight; four sessions were conducted. A moderator, fluent in Arabic and English, facilitated the group's interactions. Each group addressed five interview questions. Discussions were audiotaped and transcribed with the expressed permission of study participants. Qualitative analysis consisted of careful reading of the transcripts and of the field notes for the purpose of identifying recurring themes around tobacco use. Those that emerged were Being Cool; Being able to "Nshar ma'a al shabab" (hang out with the guys); Present Orientation; Smoking feels good, tastes good, and keeps your mind off trouble; Availability and Accessibility of tobacco; and Barriers to Smoking Cessation Programs. The results of the focus group discussions provided valuable information about the tobacco use perceptions and behaviors of Arab American adolescents and the youths' need for a culturally relevant smoking cessation program. [source] From Tastes Great to Cool: Children's Food Marketing and the Rise of the SymbolicTHE JOURNAL OF LAW, MEDICINE & ETHICS, Issue 1 2007Juliet B. Schor Children's exposure to food marketing has exploded in recent years, along with rates of obesity and overweight. Children of color and low-income children are disproportionately at risk for both marketing exposure and becoming overweight.Comprehensive reviews of the literature show that advertising is effective in changing children's food preferences and diets. This paper surveys the scope and scale of current marketing practices, and focuses on the growing use of symbolic appeals that are central in food brands to themes such as finding an identity and feeling powerful and in control. These themes are so potent because they are central to children in their development and constitution of self. The paper concludes that reduction of exposure to marketing will be a central part of any successfu anti-obesity strategy. [source] Cool, calm and collected , By Claire Larson & Geoff DubberBRITISH JOURNAL OF EDUCATIONAL TECHNOLOGY, Issue 5 2009Article first published online: 12 AUG 200 No abstract is available for this article. [source] Are azole fungicides losing ground against Septoria wheat disease?PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 7 2008Resistance mechanisms in Mycosphaerella graminicola Abstract There has been a recent rapid decline in the efficacy of some, but not all, azole fungicides in controlling the Septoria leaf blotch pathogen of wheat, Mycosphaerella graminicola. Hans J. Cools and Bart A. Fraaije ask the question: can widespread resistance to all azoles develop in this pathogen? Copyright © 2008 Society of Chemical Industry [source] From small-scale habitat loopholes to decadal cycles: a habitat-based hypothesis explaining fluctuation in pelagic fish populations off PeruFISH AND FISHERIES, Issue 4 2004Arnaud Bertrand Abstract The Peru-Humboldt Current system (HCS) supports the world's largest pelagic fisheries. Among the world's eastern boundary current systems, it is the most exposed to high climatic stress and is directly affected by El Niño and La Niña events. In this volatile ecosystem, fish have been led to develop adaptive strategies in space and time. In this paper, we attempt to understand the mechanisms underlying such strategies, focusing on the El Niño 1997,98 in Peru from which an extensive set of hydrographic, capture and acoustic survey data are available. An integrated analysis of the data is crucial, as each has substantial shortcomings individually; for example, both catch data and acoustic surveys may easily lead to wrong conclusions. Existing hypotheses on anchovy and sardine alternations lead us to a ,habitat-based' synthetic hypothesis. Using our data, an integrated approach evaluated how fish responded to habitat variation, and determined the consequences in terms of fish-population variability. Various factors occurring at a range of different spatio-temporal scales were considered: interdecadal regime (warm ,El Viejo'/cool ,La Vieja' decadal scale); strength and the duration of the El Niño Southern Oscillation event (interannual scale); population condition before the event (interannual scale); fishing pressure and other predation (annual scale); changes in reproductive behaviour (intra-annual scale); presence of local upwelling (local scale). During El Niño 1997,98, anchovy was able to exploit a small-scale temporal and spatial ,loophole' inside the general unfavourable conditions. Moreover, sardine did not do better than anchovy during this El Niño and was not able to take advantage of the ,loophole' opened by this short-term event. Our results question the traditional view that El Niño is bad for anchovy and good for sardine. [source] Configuration Space Control for Wendelstein 7-XCONTRIBUTIONS TO PLASMA PHYSICS, Issue 8 2010T. Dodson Abstract The Wendelstein 7-X stellarator (W7-X) is a superconducting fusion experiment presently under construction at the Greifswald branch of the Max-Planck-Institut für Plasmaphysik in Greifswald, Germany. W7-X is a device with extreme geometrical complexity due to the close-packing of components inside the cryostat and their complex three-dimensional shapes. The task of the Configuration Space Control department is to ensure that these components do not collide with each other under the defined set of configurations such as during assembly, at cool down, or during operation at various coil currents, among others. To fulfill this task, sophisticated tools and procedures were developed and implemented within the realm of a newly founded division that focuses on design, configuration control, and configuration management. This paper will discuss the Configuration Space Control process, explore the advantages to the project resulting from the process, and demonstrate its application in the analysis of the cryogenic cooling pipes of Module 5 (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Predicting the impact of climate change on Australia's most endangered snake, Hoplocephalus bungaroidesDIVERSITY AND DISTRIBUTIONS, Issue 1 2010Trent D. Penman Abstract Aim, To predict how the bioclimatic envelope of the broad-headed snake (BHS) (Hoplocephalus bungaroides) may be redistributed under future climate warming scenarios. Location, South-eastern New South Wales, Australia. Methods, We used 159 independent locations for the species and 35 climatic variables to model the bioclimatic envelope for the BHS using two modelling approaches , Bioclim and Maxent. Predictions were made under current climatic conditions and we also predicted the species distribution under low and high climate change scenarios for 2030 and 2070. Results, Broad-headed snakes currently encompass their entire bioclimatic envelope. Both modelling approaches predict that suitable climate space for BHS will be lost to varying degrees under both climate warming scenarios, and under the worst case, only 14% of known snake populations may persist. Main conclusions, Areas of higher elevation within the current range will be most important for persistence of this species because they will remain relatively moist and cool even under climate change and will match the current climate envelope. Conservation efforts should focus on areas where suitable climate space may persist under climate warming scenarios. Long-term monitoring programs should be established both in these areas and where populations are predicted to become extirpated, so that we can accurately determine changes in the distribution of this species throughout its range. [source] Palaeomonsoon variability in the southern fringe of the Badain Jaran Desert, China, since 130 ka BPEARTH SURFACE PROCESSES AND LANDFORMS, Issue 3 2006Quanzhou Gao Abstract Taking the Chagelebulu Stratigraphic Profile as a typical example, a comprehensive study has been conducted to elucidate the palaeoclimatic and geomorphic evolution patterns in the southern fringe of the Badain Jaran Desert, which were found to be complex and polycyclic in the past 130 ka. However, the fluctuating magnitude is not as remarkable as that in the eastern China sandy region. The shift in climate from interglacial to glacial and the uplift process of the Qinghai,Xizang Plateau are the two leading forces driving the evolution of the climate and desert landforms in this area. Seventeen cycles of cold, dry and warm, humid climatic stages were recognized in the Upper Pleistocene Series of the profile. The sharp uplift of the Qinghai,Xizang Plateau superimposed a cool and arid climatic trend in this area. As a result of the climatic changes, the desert in this area has undergone multiple stages of expansion and contraction since 130 ka bp. The middle Holocene Epoch and the early stage of the Late Pleistocene Period were the main periods when the sand dunes became stabilized, and the early and late phases of the Holocene Epoch and late phase of the Pleistocene Epoch were the main periods when the previously stabilized sand dunes became mobile. The late phase of the Pleistocene Epoch was the most mobile stage, when the aeolian sand activities formed the essential geomorphic pattern of the Badain Jaran Desert. Copyright © 2005 John Wiley & Sons, Ltd. [source] Trout density and health in a stream with variable water temperatures and trace element concentrations: Does a cold-water source attract trout to increased metal exposure?ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2009David D. Harper Abstract A history of hard-rock mining has resulted in elevated concentrations of heavy metals in Prickly Pear Creek (MT, USA). Remediation has improved water quality; however, dissolved zinc and cadmium concentrations still exceed U.S. Environmental Protection Agency water-quality criteria. Physical habitat, salmonid density, fish health, and water quality were assessed, and metal concentrations in fish tissues, biofilm, and macroinvertebrates were determined to evaluate the existing condition in the watershed. Cadmium, zinc, and lead concentrations in fish tissues, biofilm, and invertebrates were significantly greater than those at the upstream reference site and an experimental site farther downstream of the confluence. Fish densities were greatest, and habitat quality for trout was better, downstream of the confluence, where water temperatures were relatively cool (16°C). Measures of fish health (tissue metal residues, histology, metallothionein concentrations, and necropsies), however, indicate that the health of trout at this site was negatively affected. Trout were in colder but more contaminated water and were subjected to increased trace element exposures and associated health effects. Maximum water temperatures in Prickly Pear Creek were significantly lower directly below Spring Creek (16°C) compared to those at an experimental site 10 km downstream (26°C). Trout will avoid dissolved metals at concentrations below those measured in Prickly Pear Creek; however, our results suggest that the preference of trout to use cool water temperatures may supersede behaviors to avoid heavy metals. [source] Retail Store Lighting for Elderly Consumers: An Experimental ApproachFAMILY & CONSUMER SCIENCES RESEARCH JOURNAL, Issue 4 2007Nam-Kyu Park The study presents an investigation of the influence of the color of light on readability by figure to background value contrast, color perception, and overall room-light estimation for elderly consumers in an experimental setting representing a retail store. A factorial design with repeated measures was used to identify the impact of three independent variables: (a) lamp color temperatures, (b) lamp color-rendering properties, and (c) age of the participants. The results show that older adults perceived the higher color temperature light source as less cool than did younger adults. Older adults rated their level of comfort and preference higher than the younger participants under all lighting conditions. Regarding readability, higher color-rendering light sources provide better readability, and older adults have more difficulty with warmer lighting when value contrasts were reduced. Implications from this study can be applied to retail lighting techniques to attract elderly consumers. [source] Larval fish assemblages and water mass structure off the oligotrophic south-western Australian coastFISHERIES OCEANOGRAPHY, Issue 1 2008B. A. MUHLING Abstract Larval fish assemblages were sampled using replicated oblique bongo net tows along a five-station transect extending from inshore (18 m depth) to offshore waters (1000 m depth) off temperate south-western Australia. A total of 148 taxa from 93 teleost families were identified. Larvae of Gobiidae and Blenniidae were abundant inshore, while larvae of pelagic and reef-dwelling families, such as Clupeidae, Engraulidae, Carangidae and Labridae were common in continental shelf waters. Larvae of oceanic families, particularly Myctophidae, Phosichthyidae and Gonostomatidae, dominated offshore assemblages. Multivariate statistical analyses revealed larval fish assemblages to have a strong temporal and spatial structure. Assemblages were distinct among seasons, and among inshore, continental shelf and offshore sampling stations. Inshore larval fish assemblages were the most seasonal, in terms of species composition and abundance, with offshore assemblages the least seasonal. However, larval fish assemblages were most closely correlated to water mass, with species distributions reflecting both cross-shelf and along-shore oceanographic processes and events. Similarity profile (SIMPROF) analysis suggested the presence of twelve distinct larval fish assemblages, largely delineated by water depth and season. The strength and position of the warm, southward flowing Leeuwin Current, and of the cool, seasonal, northward flowing Capes Current, were shown to drive much of the variability in the marine environment, and thus larval fish assemblages. [source] Paleoindian geoarchaeology and paleoenvironments of the western Killpecker Dunes, Wyoming, U.S.A.GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 1 2003James H. Mayer The Killpecker Dunes in southwestern Wyoming have long been known to contain evidence for Paleoindian occupation. This paper presents the results of geoarchaeological investigations in the western, dormant portion of the Killpecker Dunes. Five localities, including the Krmpotich Folsom and Finley Cody Complex sites, were examined in order to better understand the Paleoindian geochronology of the dune field, and to facilitate a late Quaternary paleoenvironmental reconstruction. Age control is provided by radiocarbon, optical, and artifact ages. Four late Quaternary eolian units, designated as strata 1,4, were recognized; strata 1 and 2 are relevant to the Paleoindian record. Aggradation of stratum 1 began by at least 14,690 cal yr (,12,550 14C yr B.P.), probably in the form of a sand sheet under cool, dry conditions. Redoximorphic features are ubiquitous in stratum 1, indicating a rise in the water table during the latest Pleistocene. A buried soil (Calcid) at the top of this unit indicates a period of stability between ca. 12,000 and 11,000 14C yr B.P. and has the potential to yield Clovis (11,200,10,900 14C yr B.P.) artifacts. Unconformably overlying stratum 1 is stratum 2, a latest Pleistocene to early Holocene sand containing Folsom (10,900,10,200 14C yr B.P.) through Cody Complex (9000,8500 14C yr B.P.) occupations. A buried soil characterized by the accumulation of illuvial clay and sodium (Natrargid) occurs at the top of stratum 2 and probably formed in and around interdunal ponds. The association of Paleoindian material with the stratum 2 soil suggests the use of interdunal areas as natural traps for hunting extinct bison. The accumulation of soluble salts indicates increased rates of evaporation during the early Holocene, probably from an increase in summer insolation. Although conditions in the dune field during the early Holocene became increasingly dry, they were probably moister than at present. © 2003 Wiley Periodicals, Inc. [source] Numerical modeling of hydrothermal zinc silicate and sulfide mineralization in the Vazante deposit, BrazilGEOFLUIDS (ELECTRONIC), Issue 2 2009M. S. APPOLD Abstract The Vazante zinc deposit in central Brazil is currently the world's largest known example of a hypogene nonsulfide (i.e. willemite-dominant) zinc deposit. The mineralization is hypothesized to have formed as a result of mixing between a hot, acidic, reducing, metal-rich brine and a cool, more basic and dilute, metal-poor meteoric fluid. The present study sought to investigate this scenario by quantifying the individual effects of temperature, pH, salinity, and oxidation state on willemite and sphalerite solubility, and modeling their combined effects during mixing through reaction path and reactive transport modeling. Solubility calculations showed that in an initially hot, moderately acidic, reducing, metal-rich ore fluid saturated with respect to silica, willemite solubility is relatively insensitive to changes in temperature and log , but highly sensitive to changes in pH and salinity. In contrast, sphalerite solubility was highly sensitive to changes in temperature and log , as well as salinity, and was less sensitive than willemite to changes in pH. Reaction path models sought to extend these observations by modeling the geochemistry of mixing. The results show that mixing is able to produce most of the major zinc ore and gangue minerals observed in the field, though not necessarily at the same paragenetic stages, and that both compositional and temperature changes from mixing are needed. Reactive transport models were formulated to investigate spatial patterns of mineralization. The results showed that sphalerite deposition was strongly controlled by temperature and concentrated in the regions of greatest temperature change. Willemite deposition was concentrated along the interface between the metal-rich ore fluid and the surrounding meteoric fluid. The more rapid transport of solute than heat, in conjunction with the higher concentration of silica than sulfide in both fluids meant that willemite mineralization developed over a broader region and in greater concentrations compared with sphalerite. [source] Soil-atmospheric exchange of CO2, CH4, and N2O in three subtropical forest ecosystems in southern ChinaGLOBAL CHANGE BIOLOGY, Issue 3 2006XULI TANG Abstract The magnitude, temporal, and spatial patterns of soil-atmospheric greenhouse gas (hereafter referred to as GHG) exchanges in forests near the Tropic of Cancer are still highly uncertain. To contribute towards an improvement of actual estimates, soil-atmospheric CO2, CH4, and N2O fluxes were measured in three successional subtropical forests at the Dinghushan Nature Reserve (hereafter referred to as DNR) in southern China. Soils in DNR forests behaved as N2O sources and CH4 sinks. Annual mean CO2, N2O, and CH4 fluxes (mean±SD) were 7.7±4.6 Mg CO2 -C ha,1 yr,1, 3.2±1.2 kg N2O-N ha,1 yr,1, and 3.4±0.9 kg CH4 -C ha,1 yr,1, respectively. The climate was warm and wet from April through September 2003 (the hot-humid season) and became cool and dry from October 2003 through March 2004 (the cool-dry season). The seasonality of soil CO2 emission coincided with the seasonal climate pattern, with high CO2 emission rates in the hot-humid season and low rates in the cool-dry season. In contrast, seasonal patterns of CH4 and N2O fluxes were not clear, although higher CH4 uptake rates were often observed in the cool-dry season and higher N2O emission rates were often observed in the hot-humid season. GHG fluxes measured at these three sites showed a clear increasing trend with the progressive succession. If this trend is representative at the regional scale, CO2 and N2O emissions and CH4 uptake in southern China may increase in the future in light of the projected change in forest age structure. Removal of surface litter reduced soil CO2 effluxes by 17,44% in the three forests but had no significant effect on CH4 absorption and N2O emission rates. This suggests that microbial CH4 uptake and N2O production was mainly related to the mineral soil rather than in the surface litter layer. [source] Is the Sonoran Desert losing its cool?GLOBAL CHANGE BIOLOGY, Issue 12 2005Jeremy L. Weiss Abstract Freezing temperatures strongly influence vegetation in the hottest desert of North America, in part determining both its overall boundary and distributions of plant species within. To evaluate recent variability of freezing temperatures in this context, minimum temperature data from weather stations in the Sonoran Desert are examined. Data show widespread warming trends in winter and spring, decreased frequency of freezing temperatures, lengthening of the freeze-free season, and increased minimum temperatures per winter year. Local land use and multidecadal modes of the global climate system such as the Pacific decadal oscillation and the Atlantic multidecadal oscillation do not appear to be principal drivers of this warming. Minimum temperature variability in the Sonoran Desert does, however, correspond to global temperature variability attributed to human-dominated global warming. With warming expected to continue at faster rates throughout the 21st century, potential ecological responses may include contraction of the overall boundary of the Sonoran Desert in the south-east and expansion northward, eastward, and upward in elevation, as well as changes to distributions of plant species within and other characteristics of Sonoran Desert ecosystems. Potential trajectories of vegetation change in the Sonoran Desert region may be affected or made more difficult to predict by uncertain changes in warm season precipitation variability and fire. Opportunities now exist to investigate ecosystem response to regional climate disturbance, as well as to anticipate and plan for continued warming in the Sonoran Desert region. [source] Plant species richness in continental southern Siberia: effects of pH and climate in the context of the species pool hypothesisGLOBAL ECOLOGY, Issue 5 2007Milan Chytrý ABSTRACT Aim, Many high-latitude floras contain more calcicole than calcifuge vascular plant species. The species pool hypothesis explains this pattern through an historical abundance of high-pH soils in the Pleistocene and an associated opportunity for the evolutionary accumulation of calcicoles. To obtain insights into the history of calcicole/calcifuge patterns, we studied species richness,pH,climate relationships across a climatic gradient, which included cool and dry landscapes resembling the Pleistocene environments of northern Eurasia. Location, Western Sayan Mountains, southern Siberia. Methods, Vegetation and environmental variables were sampled at steppe, forest and tundra sites varying in climate and soil pH, which ranged from 3.7 to 8.6. Species richness was related to pH and other variables using linear models and regression trees. Results, Species richness is higher in areas with warmer winters and at medium altitudes that are warmer than the mountains and wetter than the lowlands. In treeless vegetation, the species richness,pH relationship is unimodal. In tundra vegetation, which occurs on low-pH soils, richness increases with pH, but it decreases in steppes, which have high-pH soils. In forests, where soils are more acidic than in the open landscape, the species richness,pH relationship is monotonic positive. Most species occur on soils with a pH of 6,7. Main conclusions, Soil pH in continental southern Siberia is strongly negatively correlated with precipitation, and species richness is determined by the opposite effects of these two variables. Species richness increases with pH until the soil is very dry. In dry soils, pH is high but species richness decreases due to drought stress. Thus, the species richness,pH relationship is unimodal in treeless vegetation. Trees do not grow on the driest soils, which results in a positive species richness,pH relationship in forests. If modern species richness resulted mainly from the species pool effects, it would suggest that historically common habitats had moderate precipitation and slightly acidic to neutral soils. [source] Climate change and grasslands through the ages: an overviewGRASS & FORAGE SCIENCE, Issue 2 2007L. 't Mannetje Summary Change from cool to warm temperatures and vice versa have occurred throughout geological time. During the Jurassic and Cretaceous periods (206,65 million years ago, Ma) the climate was more uniformly warm and moist than at present and tropical rainforests were widespread. Grasses evolved during the Jurassic period and they expanded greatly as the climate differentiated with reduced rainfall and temperatures. C4 -grasses probably arose during the Oligocene period (24,35 Ma). During the Miocene period (23·8,5·3 Ma) grasslands expanded into huge areas (e.g. prairies in the USA, steppe in Eurasia, and pampas and llanos in South America). During the Quaternary period (1·8 Ma till now) some twenty-two different ice ages with periodicities of about 100 000 years occurred. Eighteen-thousand years ago, north-western Europe had a polar climate with tundra vegetation and the Mediterranean region was covered by steppe. During that time Amazonia was so dry that it was covered in extensive areas of savanna and the Sahara expanded rapidly. Only in the last 10 000 years has a closed rainforest covered the Amazonian region again. However, 9000 years ago a brief period of global warming caused excessive rains, which caused the sea and river levels to rise in north-western Europe with tremendous loss of life. The present period of extreme dryness in the Sahara only started some 5000 years ago and then the desert expanded rapidly into the Sahel. Before that the Sahara was covered by steppe. Global warming took place between about ad 900 and about ad 1200 or 1300 just before the Little Ice Age (1550,1700 ad). The article concludes with a description of temperature and vegetation changes that are occurring in Europe at present. It is predicted that C4 -grasses, which are already present in southern Europe, will further expand but that, in the short term, land abandonment will have much more deleterious effects than temperature change due to increased wild fires, loss of biodiversity and desertification. [source] The potential roles of biological soil crusts in dryland hydrologic cyclesHYDROLOGICAL PROCESSES, Issue 15 2006Jayne Belnap Abstract Biological soil crusts (BSCs) are the dominant living cover in many drylands of the world. They possess many features that can influence different aspects of local hydrologic cycles, including soil porosity, absorptivity, roughness, aggregate stability, texture, pore formation, and water retention. The influence of biological soil crusts on these factors depends on their internal and external structure, which varies with climate, soil, and disturbance history. This paper presents the different types of biological soil crusts, discusses how crust type likely influences various aspects of the hydrologic cycle, and reviews what is known and not known about the influence of biological crusts on sediment production and water infiltration versus runoff in various drylands around the world. Most studies examining the effect of biological soil crusts on local hydrology are done by comparing undisturbed sites with those recently disturbed by the researchers. Unfortunately, this greatly complicates interpretation of the results. Applied disturbances alter many soil features such as soil texture, roughness, aggregate stability, physical crusting, porosity, and bulk density in ways that would not necessarily be the same if crusts were not naturally present. Combined, these studies show little agreement on how biological crusts affect water infiltration or runoff. However, when studies are separated by biological crust type and utilize naturally occurring differences among these types, results indicate that biological crusts in hyperarid regions reduce infiltration and increase runoff, have mixed effects in arid regions, and increase infiltration and reduce runoff in semiarid cool and cold drylands. However, more studies are needed before broad generalizations can be made on how biological crusts affect infiltration and runoff. We especially need studies that control for sub-surface soil features such as bulk density, micro- and macropores, and biological crust structure. Unlike the mixed effects of biological crusts on infiltration and runoff among regions, almost all studies show that biological crusts reduce sediment production, regardless of crust or dryland type.Copyright © 2006 John Wiley & Sons, Ltd. [source] Indoor Air Quality in the 21st Century: Search for ExcellenceINDOOR AIR, Issue 2 2000P. OLE FANGER Abstract Field studies demonstrate that there are substantial numbers of dissatisfied people in many buildings, among them those suffering from sick building syndrome (SBS) symptoms, even though existing standards and guidelines are met. The reason is that the requirements specified in these standards are rather low, allowing a substantial group of people to become dissatisfied and to be adversely affected. A paradigm shift from rather mediocre to excellent indoor environments is foreseen in the 21st century. Based on existing information and on new research results, five principles are suggested as elements behind a new philosophy of excellence: 1) better indoor air quality increases productivity and decreases SBS symptoms; 2) unnecessary indoor pollution sources should be avoided; 3) the air should be served cool and dry to the occupants; 4) "personalized air", i.e. a small amount of clean air, should be served gently, close to the breathing zone of each individual; and 5) individual control of the thermal environment should be provided. These principles of excellence are compatible with energy efficiency and sustainability. [source] Fabrication of Precise Fluidic Structures in LTCCINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 1 2009Fred Barlow A number of emerging applications of low-temperature co-fired ceramic (LTCC) require embedded fluidic structure within the co-fired ceramic and or precise external dimensional tolerances. These structures enable the control of fluids for cooling, sensing, and biomedical applications, and variations in their geometry from the design can have a significant impact on the overall performance of the devices. One example of this type of application is a multilayer cooler developed recently by the authors for cooling laser diode bars. In many laser systems, laser diodes are the primary emitters, or assemblies of these diode bars are used to pump traditional laser crystals such as Nd:YLF. Assemblies of these diodes require large amounts of electrical current for proper operation, and the device operating temperature must be carefully controlled in order to avoid a shift in the output wavelength. These diodes are packaged into water-cooled assemblies and by their nature dissipate enormous amounts of heat, with waste heat fluxes on the order of 2000 W/cm2. The traditional solution to this problem has been the development of copper multilayer coolers. Assemblies of laser diodes are then formed by stacking these diode bars and coolers. Several problems exist with this approach including the erosion of the copper coolers by the coolant, a requirement for the use of deionized water within the system, and a significant CTE mismatch between the diode bar and the metal cooler. Diodes are bonded to these metal structures and liquid coolant is circulated through the metal layers in order to cool the diode bar. In contrast, the coolers developed by the authors utilize fluid channels and jets formed within LTCC as well as embedded cavity structures to control the flow of a high-velocity liquid and actively cool the laser diode bars mounted on the surface of the LTCC., The dimensional tolerances of these cooler assemblies and complex shapes that are used to control the fluid can have a significant impact on the overall performance of the laser system. This paper describes the fabrication process used to create the precise channel and jet structures used in these LTCC-based coolers, as well as some of the challenges associated with these processes. [source] The Gulf Stream and Atlantic sea-surface temperatures in AD1790,1825INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 12 2010G. van der Schrier Abstract We present gridded sea-surface temperatures (SSTs) for the Atlantic basin (45°S,60°N) as averages over the period AD1790,1825, based on early-instrumental SST data. The original measurements were compiled by Major James Rennell and made by numerous British naval vessels on behalf of the British Admiralty. We describe the digitization of this dataset and the reconstruction of spatially coherent, averaged conditions for the boreal cold (November-March) and warm (May,September) season using a reduced space optimal interpolation (RSOI) technique, in which the data is projected on a limited number of empirical orthogonal functions. This approach is validated on modern data that are sampled in a similar way as the early-instrumental data. The reconstruction for the November,March period shows a large area with anomalously high temperatures from the point where the Gulf Stream separates from the coast until ca. 20°W. A tongue of anomalous cool water is found at the eastern side of the North Atlantic basin, along the coast of Europe and northern Africa. In the northeastern South Atlantic, anomalously high temperatures are found, while temperatures in the southwestern South Atlantic are anomalously cool. For the March,September season, anomalous temperatures in the South Atlantic are similar, but stronger, compared with those in the boreal cold season. Over the North Atlantic, there is not much similarity between the current SST reconstructions and those published in the late 1950s. Copyright © 2009 Royal Meteorological Society [source] Simple radiative models for surface warming and upper-troposphere coolingINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 11 2009P. N. Keating Abstract A simple model of greenhouse-gas radiative processes intended to make the surface-warming effect of water-vapour and CO2 absorption more readily understandable leads to a conclusion that the greenhouse gases also cool the upper troposphere. The results from the simple model are compared with experimental observations, and a functional form for the decline of vertical convection and water-vapour radiation near the tropopause is derived from previously unexplained high-altitude cooling-trend data. A possible reason why global climate models do not show the observed upper-troposphere cooling trend is tentatively suggested. Copyright © 2008 Royal Meteorological Society [source] Preliminary climatology and improved modelling of south Indian Ocean and Southern Ocean mid-latitude cyclonesINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 10 2004Bruce W. Buckley Abstract The intense mid-latitude cyclones that traverse the southern waters of the Indian Ocean, between South Africa and southwestern Western Australia, are among the strongest depressions found anywhere in the world, outside tropical waters. Near-surface winds that exceed storm force (i.e. 24 m/s or 48 knots), and central pressures of 960 hPa and lower, are relatively common for these systems. They pose a constant threat to both open ocean and coastal shipping, and regularly generate severe weather over the populated southwestern corner of Australia. Large ocean waves and swell produce extensive coastal inundation and erosion. There were two main aims in this study. The first aim was to develop a preliminary climatology of these intense mid-latitude cyclones, for the region 20,60 °S, 30,130 °E. The climatology, which is the first that we are aware of for this notoriously data-sparse region, is based largely upon satellite observations, particularly scatterometer data, and is supplemented by ship, buoy and all available land observations. The climatology revealed that, historically, the frequency and intensity of the mid-latitude cyclones in this domain have been significantly underestimated. This underestimation has resulted in analyses that have serious flaws, and the resultant operational forecasts provided to the duty forecasters in the regional forecast centre located in Perth, Western Australia, are of highly variable quality. A number of other climatological features of these storms are discussed in this article. The second aim was to identify the factors that can contribute to a significant improvement in model forecasts of these storms. So far, there have been very few studies of explosively developing cyclones over this part of the world. Results are presented here from a series of high-resolution numerical simulations of an intense cool season Southern Ocean cyclone that developed in 2003, using the HIRES numerical weather prediction model developed by L.M. Leslie. Here, we examine the sensitivity of the cyclone predictions to both model resolution and the initial analyses. The predicted variables of most interest are the central pressure, maximum sustained near-surface wind speeds, extent of storm-force winds, and the horizontal and vertical structure of the storm. Increased detail in the initial state is provided mainly by the assimilation into the archived global operational analyses of high-resolution satellite-derived data, including QuikSCAT scatterometer winds and sea-surface temperatures. The combination of increased horizontal and vertical model resolution, and improved initial model states, was found to produce numerical forecasts with significantly more accurate wind speeds than those obtained from the coarser resolution operational models, which also did not have the benefits of all the additional data. Finally, areas of future research are outlined, including coupling the HIRES atmospheric model with ocean and wave models, to improve forecasts of the sea state, including wind wave heights, swell and storm surges. Copyright © 2004 Royal Meteorological Society [source] Sensitivity of the southern African circulation to dipole sea-surface temperature patterns in the south Indian OceanINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 4 2002C. J. C. Reason Abstract Previous observational work suggests that when sea-surface temperature (SST) is warm (cool) in the southwest Indian Ocean and cool (warm) in the southeast Indian Ocean, increased (decreased) summer rains may occur over large areas of southeastern Africa. In this study, an atmospheric general circulation model is used to investigate the sensitivity of the regional circulation and rainfall over southern Africa to these dipole SST anomalies in the subtropical south Indian Ocean. When the model is forced with positive SST anomalies in the west and negative SST anomalies in the east, increased rainfall occurs over southeastern Africa as a result of the enhanced convergence of moister than average air over the region. Enhanced evaporation occurs over the warm pole in the southwest Indian Ocean and this moist air is advected towards southeastern Africa as a result of the low-pressure anomaly generated over this pole, which strengthens the onshore flow. Increased and more intense extra-tropical cyclones occur to the southeast of South Africa, favourable for tropical,temperate trough formation. When the SST poles are reversed in sign, decreased precipitation occurs over southeastern Africa as a result of increased low-level divergence of low-level flow and this flow being drier than average. Weaker and fewer extra-tropical cyclones occur southeast of South Africa in this case. The model results are sensitive to the proximity of the southwest Indian Ocean pole to southeastern Africa. There is also sensitivity in the model low-level wind changes and precipitation anomaly over low-latitude southern Africa (but not over South Africa to any significant extent) to the presence or absence of the SST pole over the southeast Indian Ocean. Although the model resolution does not capture the details of the local SST and topographic gradients as well as one would like, the changes in model circulation and precipitation in the experiments with different SST anomalies are consistent with previous observational and theoretical work, hence increasing confidence in the robustness of the results. Copyright © 2002 Royal Meteorological Society [source] Stay cool in strokeINTERNATIONAL JOURNAL OF STROKE, Issue 1 2006Derk W. Krieger [source] Influence of Soil Temperature on Seedling Emergence and Early Growth of Peanut Cultivars in Field ConditionsJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 3 2006P. V. V. Prasad Abstract Peanut or groundnut (Arachis hypogaea L.) sown in early spring often has poor seed germination and seedling development. The influence of soil temperature on seedling emergence and early growth of six peanut cultivars (Florida MDR98, Southern Runner, Georgia Green, SunOleic 97R, Florunner and C-99R) was studied in natural field soil profiles in temperature-gradient greenhouses. We evaluated the influence of a range of soil temperatures by sowing at eight dates between January 2001 and May 2002 in Gainesville, Florida. On each sowing date, two additional temperature treatments (ambient and ambient +4.5 °C air temperature) were evaluated by sowing on either end of each greenhouse and applying differential heating. In total, 16 different soil temperature treatments were evaluated. Each treatment was replicated four times in four different greenhouses. Mean soil temperature from sowing to final emergence in different treatments ranged from 15 to 32 °C. Sowing date, temperature treatment and cultivar had significant effect on seedling emergence and development (V2 stage). For all cultivars, the lowest germination was observed at the earliest sowing date (coolest soil temperature). Among cultivars, Florida MDR98 was the most sensitive to reduced (cool) temperature with the lowest germination and smallest seedling size at 21 days after sowing, followed by Southern Runner. Georgia Green was the most cold-tolerant with the highest germination, followed by SunOleic 97R. There were no significant differences among cultivars for base temperature, which averaged 11.7 and 9.8 °C for rate of emergence and rate of development to V2 stage respectively. These results imply that cultivar choice and/or genetic improvement of peanut for cold tolerance during emergence and seedling development in regions where cooler soil temperatures persist and/or regions where early sowing is desirable. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||