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Colder Temperatures (colder + temperature)
Selected AbstractsDiagnostic criteria in patients with complex regional pain syndrome assessed in an out-patient clinicACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2010E. A. M. VAN BODEGRAVEN HOF Background: Specific criteria have been described and accepted worldwide for diagnosing patients with complex regional pain syndrome (CRPS). Nevertheless, a clear-cut diagnosis cannot be confirmed in a number of cases. Aim: The objective of this study was to investigate the effectiveness of the described diagnostic criteria used by several clinical disciplines. Methods: We included 195 patients who were referred to our pain clinic within a period of 1 year. Data were collected on patient characteristics, signs, symptoms, disease-related medication, and the background of the referring clinicians. Results: The Harden and Bruehl criteria were confirmed in 95 patients (49%). These patients used a higher than average number of analgesics, opiates, and anti-oxidants, and frequently received prescriptions for benzodiazepines instead of anti-depressants. The mean disease duration was 29 ± 4.6 months and the mean visual analogue score for pain was 8.1 ± 0.19. A subgroup of patients had a colder temperature in the affected extremity compared with the unaffected extremity. This subgroup showed a longer disease duration and higher visual analogue scale pain. Conclusion: The diagnostic criteria used to determine CRPS should be further improved. A large number of referred patients experienced substantial pain, without receiving adequate medication. Disease-related medication is unrelated to CRPS-specific disease activity. Knowledge of underlying mechanisms is warranted before an adequate pharmaceutical intervention can be considered. [source] Is natural selection a plausible explanation for the distribution of Idh- 1 alleles in the cricket Allonemobius socius?ECOLOGICAL ENTOMOLOGY, Issue 1 2006Diana L. Huestis Abstract., 1.,Allozyme alleles in natural populations have been proposed as either neutral markers of genetic diversity or the product of natural selection on enzyme function, as amino acid substitutions that change electrophoretic mobility may also alter enzyme performance. To address these possibilities, researchers have used both correlative analyses and empirical studies. 2.,Here, geographically structured variation of the enzyme isocitrate dehydrogenase (Idh- 1) in the striped ground cricket Allonemobius socius Scudder (Orthoptera: Gryllidae) is examined. The distributions of Idh- 1 alleles appear to be related to environmental gradients, as allele frequencies showed significant relationships with mean annual temperature and precipitation. Specifically, the slowest mobility allele was more frequent at colder temperatures, while the converse occurred for the fastest mobility allele. 3.,An exploratory experiment was performed to examine fitness effects of possessing different Idh- 1 alleles at two temperatures to test the hypothesis that the geographic structure of this locus may reflect environmental adaptation. Results showed that a significant interaction between temperature and Idh- 1 genotype affected the number of eggs laid, with success of homozygous individuals matching environmental expectations. 4.,The above results show that (1) variation in the frequency of Idh- 1 alleles is significantly related to environmental gradients in the eastern U.S.A. and (2) alternative alleles of Idh- 1 appear to influence the egg-laying ability of individuals differently depending on environmental temperature. Together, these results suggest that natural selection is a plausible mechanism underlying the distribution of Idh- 1 alleles in this species, although more detailed studies are needed. [source] Characterization of potential stress responses in ancient Siberian permafrost psychroactive bacteriaFEMS MICROBIOLOGY ECOLOGY, Issue 1 2005Monica A. Ponder Abstract Past studies of cold-acclimated bacteria have focused primarily on organisms not capable of sub-zero growth. Siberian permafrost isolates Exiguobacterium sp. 255-15 and Psychrobacter sp. 273-4, which grow at subzero temperatures, were used to study cold-acclimated physiology. Changes in membrane composition and exopolysaccharides were defined as a function of growth at 24, 4 and ,2.5 °C in the presence and absence of 5% NaCl. As expected, there was a decrease in fatty acid saturation and chain length at the colder temperatures and a further decrease in the degree of saturation at higher osmolarity. A shift in carbon source utilization and antibiotic resistance occurred at 4 versus 24 °C growth, perhaps due to changes in the membrane transport. Some carbon substrates were used uniquely at 4 °C and, in general, increased antibiotic sensitivity was observed at 4 °C. All the permafrost strains tested were resistant to long-term freezing (1 year) and were not particularly unique in their UVC tolerance. Most of the tested isolates had moderate ice nucleation activity, and particularly interesting was the fact that the Gram-positive Exiguobacterium showed some soluble ice nucleation activity. In general the features measured suggest that the Siberian organisms have adapted to the conditions of long-term freezing at least for the temperatures of the Kolyma region which are ,10 to ,12 °C where intracellular water is likely not frozen. [source] Contemporary climate change in the Sonoran Desert favors cold-adapted speciesGLOBAL CHANGE BIOLOGY, Issue 5 2010SARAH KIMBALL Abstract Impacts of long-term climate shifts on the dynamics of intact communities within species ranges are not well understood. Here, we show that warming and drying of the Southwestern United States over the last 25 years has corresponded to a shift in the species composition of Sonoran Desert winter annuals, paradoxically favoring species that germinate and grow best in cold temperatures. Winter rains have been arriving later in the season, during December rather than October, leading to the unexpected result that plants are germinating under colder temperatures, shifting community composition to favor slow growing, water-use efficient, cold-adapted species. Our results demonstrate how detailed ecophysiological knowledge of individual species, combined with long-term demographic data, can reveal complex and sometimes unexpected shifts in community composition in response to climate change. Further, these results highlight the potentially overwhelming impact of changes in phenology on the response of biota to a changing climate. [source] Distribution and phenology of ixodid ticks in southern ZambiaMEDICAL AND VETERINARY ENTOMOLOGY, Issue 4 2002N. Speybroeck Abstract Distribution data for epidemiologically important ticks (Acari: Ixodidae) in the Southern Province of Zambia, one of the main cattle areas of the country, are presented. Boophilus microplus (Canestrini) was not recorded in southern Zambia, whereas Boophilus decoloratus (Koch) is present throughout the area. New distribution patterns for less economically important ixodid ticks are also discussed. Southern Zambia is a transition zone because it is the most northern area in Africa where mixed Rhipicephalus appendiculatus Neumann and Rhipicephalus zambeziensis Walker, Norval & Corwin populations were reported. Although a second generation of adult R. appendiculatus/R. zambeziensis was encountered, simulations indicated that this phenomenon is very rare in southern Zambia, mainly because of the colder temperatures during the early dry season and lower rainfall. These simulations were supported by a development trial under experimental conditions. Tick body size measurements showed that southern Zambian ticks are larger than eastern Zambian R. appendiculatus. It is hypothesized that body size is related to diapausing intensity in this species. The epidemiological consequences are that a different approach to control Theileria parva (Theiler) (Piroplasmida: Theileriidae) and other tick-borne diseases is needed in southern Zambia, compared to the one adopted in eastern Zambia. [source] Estimating Fine Root Turnover in Tropical Forests along an Elevational Transect using MinirhizotronsBIOTROPICA, Issue 5 2008Sophie Graefe ABSTRACT Growth and death of fine roots represent an important carbon sink in forests. Our understanding of the patterns of fine root turnover is limited, in particular in tropical forests, despite its acknowledged importance in the global carbon cycle. We used the minirhizotron technique for studying the changes in fine root longevity and turnover along a 2000-m-elevational transect in the tropical mountain forests of South Ecuador. Fine root growth and loss rates were monitored during a 5-mo period at intervals of four weeks with each 10 minirhizotron tubes in three stands at 1050, 1890, and 3060 m asl. Average root loss rate decreased from 1.07 to 0.72 g/g/yr from 1050 to 1890 m, indicating an increase in mean root longevity with increasing elevation. However average root loss rate increased again toward the uppermost stand at 3060 m (1.30 g/g/yr). Thus, root longevity increased from lower montane to mid-montane elevation as would be expected from an effect of low temperature on root turnover, but it decreased further upslope despite colder temperatures. We suggest that adverse soil conditions may reduce root longevity at high elevations in South Ecuador, and are thus additional factors besides temperature that control root dynamics in tropical mountain forests. [source] Peat multi-proxy data from Männikjärve bog as indicators of late Holocene climate changes in EstoniaBOREAS, Issue 1 2007UULLE SILLASOO Sillasoo, Ü., Mauquoy, D., Blundell, A., Charman, D., Blaauw, M., Daniell, J. R. G., Toms, P., Newberry, J., Chambers, F M. & Karofeld, E. 2007 (January): Peat multi-proxy data from Männikjärve bog as indicators of late Holocene climate changes in Estonia. Boreas, Vol. 36, pp. 20,37. Oslo. ISSN 0300,9483. As part of a wider project on European climate change over the past 4500 years, a 4.5-m peat core was taken from a lawn microform on Männikjärve bog, Estonia. Several methods were used to yield proxy-climate data: (i) a quadrat and leaf-count method for plant macrofossil data, (ii) testate amoebae analysis, and (iii) colorimetric determination of peat humification. These data are provided with an exceptionally high resolution and precise chronology. Changes in bog surface wetness were inferred using Detrended Correspondence Analysis (DCA) and zonation of macrofossil data, particularly concerning the occurrence of Sphagnum balticum, and a transfer function for water-table depth for testate amoebae data. Based on the results, periods of high bog surface wetness appear to have occurred at c. 3100,3010,2990,2300, 1750,1610, 1510, 1410, 1110, 540 and 310 cal. yr BP, during four longer periods between c. 3170 and 2850 cal. yr BP, 2450 and 2000 cal. yr BP, 1770 and 1530 cal. yr BP and in the period from 880 cal. yr BP until the present. In the period between 1770 and 1530 cal. yr BP, the extension or initiation of a hollow microtope occurred, which corresponds with other research results from Mannikjarve bog. This and other changes towards increasing bog surface wetness may be the responses to colder temperatures and the predominance of a more continental climate in the region, which favoured the development of bog micro-depressions and a complex bog microtopography. Located in the border zone of oceanic and continental climatic sectors, in an area almost without land uplift, this study site may provide valuable information about changes in palaeohydrological and palaeoclimatological conditions in the northern parts of the eastern Baltic Sea region. [source] | ||||||||||