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Cold Temperatures (cold + temperature)
Selected AbstractsEffects of Decomposition on Gunshot Wound Characteristics: Under Cold Temperatures with No Insect ActivityJOURNAL OF FORENSIC SCIENCES, Issue 2 2009Lauren E. MacAulay B.Sc. (Hons) Abstract:, Information on gunshot wound characteristics has been well documented; however, there is little documented information on the effects of decomposition or environmental conditions on gunshot wound characteristics. This study was conducted in order to determine if decomposition would obscure or alter the physical surface characteristics of gunshot wounds when exposed to a low temperature environment. The study was conducted from November 2005 to January 2006 in Nova Scotia, Canada in forested and exposed environments, with air temperatures between ,10°C and +10°C. Pigs were used as human models and were shot six times each at three different ranges (contact, 2.5 cm, and 1.5 m). Gunshot wound characteristics persisted until the wounds were covered with ice and snow, after which changes were observed. The changes were recognized as being unique to the different ranges of gunshots and it was concluded that changes due to decomposition under the conditions tested would not affect the collection and interpretation of gunshot wound evidence. [source] Seasonal shifts in dormancy status, carbohydrate metabolism, and related gene expression in crown buds of leafy spurgePLANT CELL & ENVIRONMENT, Issue 12 2005JAMES V. ANDERSON ABSTRACT Crown buds of field-grown leafy spurge (Euphorbia esula L.) were examined to determine relationships between carbohydrate metabolism and gene expression throughout para-, endo-, and eco-dormancy during the transition from summer, autumn, and winter, respectively. The data indicates that endo-dormancy plays a role in preventing new shoot growth during the transition from autumn to winter. Cold temperature was involved in breaking endo-dormancy, inducing flowering competence, and inhibiting shoot growth. An inverse relationship developed between starch and soluble sugar (mainly sucrose) content in buds during the shift from para- to endo-dormancy, which continued through eco-dormancy. Unlike starch content, soluble sugars were lowest in crown buds during para-dormancy but increased over two- to three-fold during the transition to endo-dormancy. Several genes (AGPase, HK, SPS, SuSy, and UGPase) coding for proteins involved in sugar metabolism were differentially regulated in conjunction with well-defined phases of dormancy in crown buds. Marker genes for S-phase progression, cell wall biochemistry, or responsive to auxin were also differentially regulated during transition from para-, endo-, and eco-dormancy. The results were used to develop a model showing potential signalling pathways involved in regulating seasonal dormancy status in leafy spurge crown buds. [source] Intestinal microbiota variation in Senegalese sole (Solea senegalensis) under different feeding regimesAQUACULTURE RESEARCH, Issue 11 2007Beatriz Martin-Antonio Abstract The aim of this study was to determine the influence of the feeding regimes in Senegalese sole (Solea senegalensis) cultured under extensive, semi-extensive and intensive production systems. A total of 254 bacterial isolates from guts of fish cultured under different production systems and feeding regimes were tested. Biochemical tests and genetic analyses based on the 16S rDNA sequence analysis were conduced to identify bacterial strains. Vibrio species were the most represented taxonomic group in the culturable microbiota of S. senegalensis guts tested. Particularly, Vibrio ichthyoenteri was the most frequently isolated Vibrio species. Comparison among diets showed a significant reduction (P<0.05) in vibrio percentages and a higher occurrence of Shewanella species in Senegalese soles fed polychaeta. In addition, a major influence of environmental temperature on microbiota composition was detected. Cold temperatures brought about a change in the percentages of Vibrio species and a higher representation of ,-Proteobacteria in both outdoor systems (extensive and semi-extensive). The significant differences between intestinal bacterial composition in Senegalese soles fed commercial diets and natural preys (polychaeta) reveal the necessity to develop specific optimized diets for the intensive rearing of this fish species. [source] Mutagenesis of ,-tubulin cysteine residues in Saccharomyces cerevisiae: Mutation of cysteine 354 results in cold-stable microtubulesCYTOSKELETON, Issue 2 2001Mohan L. Gupta Jr. Abstract Cysteine residues play important roles in the control of tubulin function. To determine which of the six cysteine residues in ,-tubulin are critical to tubulin function, we mutated the cysteines in Saccharomyces cerevisiae ,-tubulin individually to alanine and serine residues. Of the twelve mutations, only three produced significant effects: C12S, C354A, and C354S. The C12S mutation was lethal in the haploid, but the C12A mutation had no observable phenotype. Based on interactive views of the electron crystallographic structure of tubulin, we suggest that substitution of serine for cysteine at this position has a destabilizing effect on the interaction of tubulin with the exchangeable GTP. The two C354 mutations, although not lethal, produced dramatic effects on microtubules and cellular processes that require microtubules. The C354 mutant cells had decreased growth rates, a slowed mitosis, increased resistance to benomyl, and impaired nuclear migration and spindle assembly. The C354A mutation produced a more severe phenotype than the C354S mutation: the haploid cells had chromosome segregation defects, only 50% of cells in a culture were viable, and a significant percentage of the cells were misshapened. Cytoplasmic microtubules in the C354S and C354A cells were longer than in the control strain and spindle structures appeared shorter and thicker. Both cytoplasmic and spindle microtubules in the two C354 mutants were extremely stable to cold temperature. After 24 h at 4°C, the microtubules were still present and, in fact, very long and thick tubulin polymers had formed. Evidence exists to indicate that the C354 residue in mammalian tubulin is near the colchicine binding site and the electron crystal structure of tubulin places the residue at the interface between the ,- and ,-subunits. The sulfhydryl group is situated in a polar environment, which may explain why the alanine mutation is more severe than the serine mutation. When the C12S and the two C354 mutations were made in a diploid strain, the mutated tubulin was incorporated into microtubules and the resulting heterozygotes had phenotypes that were intermediate between those of the mutated haploids and the wild-type strains. The results suggest that the C12 and C354 residues play important roles in the structure and function of tubulin. Cell Motil. Cytoskeleton 49:67,77, 2001. © 2001 Wiley-Liss, Inc. [source] White muscle 20S proteasome activity is negatively correlated to growth rate at low temperature in the spotted wolffish Anarhichas minorJOURNAL OF FISH BIOLOGY, Issue 7 2010S. G. Lamarre The effect of temperature and mass on specific growth rate (G) was examined in spotted wolffish Anarhichas minor of different size classes (ranging from 60 to 1500 g) acclimated at different temperatures (4, 8 and 12° C). The relationship between G and 20S proteasome activity in heart ventricle, liver and white muscle tissue was then assessed in fish acclimated at 4 and 12° C to determine if protein degradation via the proteasome pathway could be imposing a limitation on somatic growth. Cardiac 20S proteasome activity was not affected by acclimation temperature nor fish mass and had no correlation with G. Hepatic 20S proteasome activity was higher at 12° C but did not show any relationship with G. Partial correlation analysis showed that white muscle 20S proteasome activity was negatively correlated to G (partial Pearson's r = ,0·609) but only at cold acclimation temperature (4° C). It is suggested that acclimation to cold temperature involves compensation of the mitochondrial oxidative capacity which would in turn lead to increased production of oxidatively damaged proteins that are degraded by the proteasome pathway and ultimately negatively affects G at cold temperature. [source] Submillimetre observations of z > 6 quasarsMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2004Ian Robson ABSTRACT We report on submillimetre (submm) observations of three high-redshift quasars (z > 6) made using the SCUBA camera on the James Clerk Maxwell Telescope (JCMT). Only one of the sample was detected (>10, significance) at 850 ,m , SDSS J1148+5251 (z= 6.43). It was also detected at 450 ,m (>3, significance), one of the few quasars at z > 4 for which this has been the case. In combination with existing millimetric data, the 850- and 450-,m detections allow us to place limits on the temperature of the submm-emitting dust. The dust temperature is of no trivial importance given the high redshift of the source, since a cold temperature would signify a large mass of dust to be synthesized in the little time available (as an extreme upper limit in only 0.9 Gyr since z=,). We find, however, that the combined millimetre and submm data for the source cannot simply be characterized using the single-temperature greybody fit that has been used at lower redshifts. We discuss the results of the observing and modelling, and speculate as to the origin of the deviations. [source] Phytochromes differentially regulate seed germination responses to light quality and temperature cues during seed maturationPLANT CELL & ENVIRONMENT, Issue 10 2009JENNIFER M. DECHAINE ABSTRACT The ratio of red to far-red light (R : FR) experienced by seeds during maturation affects germination, but the genetic regulation of this effect is poorly understood. In Arabidopsis thaliana, responses to R : FR are governed by five phytochrome photoreceptors, PHYA,PHYE. PHYA, PHYB and PHYE mediate germination, but their roles in germination response to the seed maturation environment are largely unknown. Seeds of A. thaliana phytochrome mutants and natural accessions were matured in a factorial combination of cold (16 °C) and warm (24 °C) temperatures and high (R : FR = 1) and low (R : FR = 0.6) R : FR environments, resembling sunlight and foliar shade, respectively. Germination was observed in resulting seeds. All five phytochromes mediated germination responses to seed maturation temperature and/or R : FR environment. PHYA suppressed germination in seeds matured under cold temperature, and PHYB promoted germination under the same conditions. PHYD and PHYE promoted germination of seeds matured under warm temperature, but this effect diminished when seeds matured under reduced R : FR. The A. thaliana natural accessions exhibited interesting variation in germination responses to the experimental conditions. Our results suggest that the role of individual PHY loci in regulating plant responses to R : FR varies depending on temperature and provide novel insights into the genetic basis of maternal effects. [source] Temperature and hen harrier productivity: from local mechanisms to geographical patternsECOGRAPHY, Issue 5 2002S. M. Redpath Climate is an important factor limiting demography and distribution patterns in many organisms. For species with a broad geographical distribution, the mechanism by which climate influences demography is likely to vary dramatically from one end of the range to the other. In this paper we first assess, in a Scottish population of hen harriers Circus cyaneus, how temperature and rainfall influence adult behaviour and chick mortality patterns at the nest. We then test for associations between harrier productivity and weather across Scotland, towards the northern edge of the range, and Spain, towards the southern edge of the range. We show that during the nestling period, female brooding time increased in cold weather. Male provisioning rate was negatively related to temperature and rainfall. Chick mortality increased in cold temperatures and was most likely to occur at nests where male prey delivery rates were low relative to temperature. Annual values of harrier fledged brood size across Scotland were positively related to summer temperature suggesting that the patterns seen in one population held at a national scale. In Spain, however, the opposite patterns were observed with fledged brood size being negatively related to temperature. This shows that whilst the impact of weather on productivity may be equally strong at two ends of a geographical range, the mechanisms vary dramatically. Large-scale predictive models need to take such patterns into account. [source] Cold tolerance in obligate and cyclical parthenogens of the peach-potato aphid, Myzus persicaeECOLOGICAL ENTOMOLOGY, Issue 4 2004Christoph Vorburger Abstract., 1. Many aphids form mixed populations of cyclical and obligate parthenogens. This is puzzling, because all else being equal, obligate parthenogens should outcompete cyclical parthenogens due to the two-fold cost of sex. Yet cyclical parthenogens produce frost-resistant, diapausing eggs in autumn, while obligate parthenogens spend the winter as active stages. Frost resistance thus represents a short-term advantage to sexual reproduction mediated by winter temperatures, which may promote this coexistence. 2. Because obligate parthenogens overwinter as active stages, there may be selection for increased cold tolerance compared to cyclical parthenogens. This has the potential to gradually erode the advantage of sexually producing eggs. 3. Four obligately and four cyclically parthenogenetic lines of Myzus persicae (Sulzer) (Hemiptera: Aphididae) were collected from each of two areas differing in winter severity, and their survival after exposure to a severe experimental frost (14 h at ,9 °C), as well as their reproductive performance at a low (10 °C) and a high (20 °C) temperature were compared. 4. There was significant variation among lines in survival after the experimental frost, but this variation was neither related to their reproductive mode, nor to their area of origin. Similarly, neither reproductive mode nor origin had a significant effect on reproductive performance, independent of temperature. The average slope of the response to variation in temperature was also similar for both reproductive modes, despite the fact that slopes differed significantly among lines. 5. Within the limits of extrapolating from laboratory experiments, it is concluded that in M. persicae, the active stages of obligate parthenogens are not better adapted to cold temperatures than those of cyclical parthenogens. [source] The epigenetic calnexin-independent state is induced in response to environmental changesFEMS YEAST RESEARCH, Issue 8 2009Renée Guérin Abstract Yeasts have evolved numerous responsive pathways to survive in fluctuating and stressful environments. The endoplasmic reticulum (ER) is sensitive to adverse conditions, which are detected by response pathways to ensure correct protein folding. Calnexin is an ER transmembrane chaperone acting in both quality control of folding and response to persistent stress. Calnexin is a key protein required for viability in certain organisms such as mammals and the fission yeast Schizosaccharomyces pombe. Nevertheless, S. pombe calnexin-independent (Cin) cells were obtained after transient expression of a particular calnexin mutant. The Cin state is dominant, is stably propagated by an epigenetic mechanism and segregates in a non-Mendelian fashion to the meiotic progeny. The nucleolar protein Cif1p was identified as an inducer of the Cin state in a previous genetic screen. Here, we report the identification of novel inducers isolated in an overexpression genetic screen: pyruvate kinase (Pyk1p) and phosphoglycerate kinase (Pgk1p). Addition of pyruvate, the end product of pyruvate kinase and glycolysis, also induced calnexin independence in a dose-dependent manner. Remarkably, growth in respiration media or cold temperatures induced the appearance of Cin cells at high frequencies. Taken together, our results indicate that the Cin state can be triggered by extracellular changes, suggesting that this state represents an epigenetic adaptative response to environmental modifications. [source] On the climate and weather of mountain and sub-arctic lakes in Europe and their susceptibility to future climate changeFRESHWATER BIOLOGY, Issue 12 2009R. THOMPSON Summary 1.,The complex terrain and heterogeneous nature of the mountain environment coupled with remoteness from major centres of human activity makes mountains challenging locations for meteorological investigations. Mountainous areas tend to have more varied and more extreme weather than lowlands. 2.,The EMERGE program has the primary aim of assessing the status of remote mountain and sub-arctic lakes throughout Europe for the first time. In this study, we describe the main features of the climate, ice-cover durations and recent temperature trends of these areas. The main weather characteristics of European mountain and sub-arctic lakes are their cold temperatures and year-round precipitation. Mean annual temperatures are generally close to 0 °C, and maximum summer temperatures reasonably close to 10 °C. 3.,Maritime versus continental settings determine the main differences in annual-temperature range among lake districts (10.5 °C in Scotland to 26.7 °C in Northern Finland), and a similar factor for ice-cover duration. Radiation ranges from low (120 W m,2) in the high latitude sub-arctic and high (237 W m,2) in the southern ranges of the Pyrenees and Rila. Similarly, precipitation is high in the main Alpine chain (250 cm year,1 in the Central Southern Alps) and low in the continental sub-arctic (65 cm year,1 in Northern Finland). 4.,The main temporal patterns in air temperature follow those of the adjacent lowlands. All the lake districts warmed during the last century. Spring temperature trends were highest in Finland; summer trends were weak everywhere; autumn trends were strongest in the west, in the Pyrenees and western Alps; while winter trends varied markedly, being high in the Pyrenees and Alps, low in Scotland and Norway and negative in Finland. 5.,Two new, limnological case studies on Lake Redon, in the Pyrenees, highlight the sensitivity of remote lakes to projected changes in the global climate. These two case studies involve close linkages between extreme chemical-precipitation events and synoptic wind-patterns, and between thermocline behaviour and features of the large-scale circulation. 6.,Individual lakes can be ultra-responsive to climate change. Even modest changes in future air temperatures will lead to major changes in lake temperatures and ice-cover duration and hence probably affect their ecological status. [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] Dendroclimatic signals in long tree-ring chronologies from the Himalayas of NepalINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 7 2003Edward R. Cook Abstract We describe the development of a tree-ring chronology network in Nepal that is suitable for reconstructing temperature-related climate forcing over the past few hundred years. The network is composed of 32 tree-ring chronologies and is represented by five indigenous tree species. An empirical orthogonal function analysis of the chronologies over the common interval 1796,92 indicates the existence of coherent large-scale signals among the tree-ring chronologies that are hypothesized to reflect, in part, broad-scale climate forcing related to temperatures. A long monthly temperature record for Kathmandu is developed and used to test this hypothesis. In so doing, significant monthly and seasonal temperature responses are identified that provide guidance for the formal reconstruction of two temperature seasons: February,June (1546,91) and October,February (1605,91). Each reconstruction indicates the occurrence of unusually cold temperatures in 1815,22, which coincides with the eruption of Tambora in Indonesia. A novel method is also used to add probable missing multi-centennial temperature variance to each reconstruction. The resulting ,adjusted' reconstructions strongly reflect patterns of temperature variability associated with Little Ice Age cooling and warming into the 20th century, with the October,February season exhibiting the strongest increase in temperature over the past ,400 years. Only the October,February season shows any evidence for late- 20th century warming, whereas February,June temperatures have actually cooled since 1960 (as with the observational series). Copyright © 2003 Royal Meteorological Society [source] Testing Bergmann's rule in the presence of potentially confounding factors: a case study with three species of Galerida larks in MoroccoJOURNAL OF BIOGEOGRAPHY, Issue 4 2008Alban Guillaumet Abstract Aim, To test Bergmann's rule (which predicts a larger body size in colder areas within warm-blooded vertebrate species) in three partially sympatric species of larks (Galerida theklae, Galerida cristata and Galerida randonii) that occur in Morocco. Location, Morocco. Methods, Restriction fragment length polymorphism techniques applied on cytochrome b haplotypes were used to discriminate G. cristata and G. randonii, and to investigate the effects of interspecific hybridization in their contact zone. A comprehensive statistical framework was then designed to test Bergmann's rule in our three Galerida species (using altitude as a proxy for cold temperatures), while controlling for the possible influence of interspecific hybridization and competition and accounting for spatial autocorrelation. The method we propose is conservative in the sense that potentially confounding factors are adjusted so as to maximize their influence on the variable of interest. Results, Bergmann's rule was strongly supported in G. theklae and G. randonii. However, body size did not respond to altitude in G. cristata, a result that was not simply explained by species-specific differences in geographical ranges and altitudinal span. In G. cristata, we detected a tendency for body size to increase with aridity, in agreement with an alternative definition of Bergmann's rule. However, since G. cristata also hybridizes with G. randonii in a contact zone located in the most arid part of the range of G. cristata, we could not tease apart the relative contribution of selection and hybridization in driving this pattern. Main conclusions, This study highlights the need for careful statistical designs that allow meaningful variables to be picked out from large sets of potential factors. When taking these factors into account, we found that Bergmann's rule was still strongly supported in two out of the three species examined. [source] Melanic through nature or nurture: genetic polymorphism and phenotypic plasticity in Harmonia axyridisJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 8 2010L. J. MICHIE Abstract Individuals can adapt to heterogeneity in their environment through either local adaptation or phenotypic plasticity. Colour forms of the ladybird Harmonia axyridis are a classic example of local adaptation, in which the frequency of melanic forms varies greatly between populations. In some populations, there are also large seasonal changes in allele frequency, with melanism being costly in summer and beneficial in winter. We report that the non-melanic morph of H. axyridis dramatically increases its degree of melanization at cold temperatures. Furthermore, there is genetic variation in reaction norms, with different families responding to temperature in different ways. Variation at different spatial and temporal scales appears to have selected for either genetic or phenotypically plastic adaptations, which may be important in thermoregulation. As melanism is known to have a large effect on fitness in H. axyridis, this plasticity of melanization may have hastened its spread as an invasive species. [source] The impact of cold temperatures during grain maturation on selected quality parameters of wheatJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2007Maryke Craven Abstract The influence of sudden cold spells during grain filling of wheat on the quality traits of three South African hard red wheat cultivars (Gariep, Elands and Tugela-DN) was studied, with the emphasis on Hagberg falling number (HFN). Four treatments were used (,1 °C at soft dough stage, , 1 °C at late milk stage, , 4 °C at soft dough stage and , 4 °C at late milk stage) and were administered for one night only. From the results it was concluded that, although limited in duration, such frost conditions did have an effect on the quality of the wheat cultivars. Cultivars differed in their response to the various treatments but also as to what quality traits were affected the most. The , 4 °C at late milk stage resulted in significantly reduced HFN being measured for both Elands and Tugela-DN. A similar effect was observed for Gariep, but was not statistically significant. Although the response was limited to the main tillers only, the conclusion was made that it is probable that the reduced HFN would be visible in the pooled sample of head and side tillers. A screening protocol was suggested that would allow classification of cultivars for frost tolerance. Copyright © 2007 Society of Chemical Industry [source] A biogeographical analysis of the European Atlantic lowland heathlandsJOURNAL OF VEGETATION SCIENCE, Issue 5 2010Javier Loidi Abstract Questions: What is the climatic envelope of European Atlantic heathlands and the relationship between their floristic geographical variability and climatic parameters? Are the biogeographic patterns extracted from genuine heath plants comparable to those extracted from the accompanying flora? To what extent does the species composition extracted from phytosociological data support the current theory of refuge areas of heath vegetation in southern Atlantic Europe during the Pleistocene ice ages? Location: Atlantic Europe and NW Morocco. Methods: The geographical territory in which Atlantic heathlands occur was divided into 23 sectors following geographic and chorological criteria. A presence,absence table with 333 taxa was then constructed with the available phytosociological data. The taxa were classified into different groups according to their phytosociological affinity. Several types of numerical analysis were performed with this matrix and the climatic data obtained from meteorological sources. Results: Heathlands require a humid and oceanic climate and are limited by cold temperatures in the north and by summer droughts in the south. The highest floristic richness of this vegetation type is found in NW Iberia. Ordinations indicate a strong correlation between floristic composition of biogeographic sector and summer drought (Ios) and thermicity (It). Conclusions: The main climatic factors determining lowland heathland floristic distribution are thermicity and summer drought. The current optimal conditions for heath flora in NW Iberia suggest that there were southern refuges during the Pleistocene ice ages from which northward expansion has taken place. [source] Memories of winter: vernalization and the competence to flowerPLANT CELL & ENVIRONMENT, Issue 11 2000S. D. Michaels ABSTRACT The promotion of flowering in response to a prolonged exposure to cold temperatures (i.e. winter) is a useful adaptation for plant species that flower in the spring. This promotion is known as vernalization and results in a permanent memory of cold exposure. While the physiology of vernalization has been extensively studied in many species, the molecular mechanism of vernalization remains largely unknown. Recent studies, however, have revealed some of the molecular events that create the requirement for vernalization. In Arabidopsis, naturally occurring late-flowering ecotypes and plants containing late-flowering mutations in the autonomous floral-promotion pathway are relatively late flowering unless cold treated. The vernalization requirement of these late-flowering ecotypes and autonomous-pathway mutants is largely created by an upregulation of the floral inhibitor FLOWERING LOCUS C (FLC). After cold treatment, as imbibed seeds or young seedlings, FLC transcript levels are downregulated and remain low for the remainder of the plant's life, but return to high levels in the next generation. Plants containing a constitutively expressed 35S:FLC construct remain late flowering after cold treatment, indicating that FLC levels must be downregulated for vernalization to be effective. Thus the epigenetic downregulation of FLC appears to be a major target of the vernalization pathway and provides a molecular marker of the vernalized state. [source] Revegetation Methods for High-Elevation Roadsides at Bryce Canyon National Park, UtahRESTORATION ECOLOGY, Issue 2 2004S. L. Petersen Abstract Establishment of native plant populations on disturbed roadsides was investigated at Bryce Canyon National Park (BCNP) in relation to several revegetation and seedbed preparation techniques. In 1994, the BCNP Rim Road (2,683,2,770 m elevation) was reconstructed resulting in a 23.8-ha roadside disturbance. Revegetation comparisons included the influence of fertilizer on plant establishment and development, the success of indigenous versus commercial seed, seedling response to microsites, methods of erosion control, and shrub transplant growth and survival. Plant density, cover, and biomass were measured 1, 2, and 4 years after revegetation implementation (1995,1998). Seeded native grass cover and density were the highest on plots fertilized with nitrogen and phosphorus, but by the fourth growing season, differences between fertilized and unfertilized plots were minimal. Fertilizers may facilitate more rapid establishment of seeded grasses following disturbance, increasing soil cover and soil stability on steep and unstable slopes. However the benefit of increased soil nutrients favored few of the desired species resulting in lower species richness over time compared to unfertilized sites. Elymus trachycaulus (slender wheatgrass) plants raised from indigenous seed had higher density and cover than those from a commercial seed source 2 and 4 years after sowing. Indigenous materials may exhibit slow establishment immediately following seeding, but they will likely persist during extreme climatic conditions such as cold temperatures and relatively short growing seasons. Seeded grasses established better near stones and logs than on adjacent open microsites, suggesting that a roughened seedbed created before seeding can significantly enhance plant establishment. After two growing seasons, total grass cover between various erosion-control treatments was similar indicating that a variety of erosion reduction techniques can be utilized to reduce erosion. Finally shrub transplants showed minimal differential response to fertilizers, water-absorbing gels, and soil type. Simply planting and watering transplants was sufficient for the greatest plant survival and growth. [source] When exactly can carpal tunnel syndrome be considered work-related?ANZ JOURNAL OF SURGERY, Issue 3 2002Sonja Falkiner Background: Carpal tunnel syndrome (CTS), compression of the median nerve at the wrist, is the most frequently encountered peripheral entrapment neuropathy. Whilst rates of all other work-related conditions have declined, the number of work-related musculoskeletal disorders (which include CTS) has not changed for the past 9 years in the USA. Median days off work are also highest for CTS: 27 compared to 20 for fractures and 18 for amputations. This results in enormous Workers Compensation and other costs to the community. Awareness of CTS as a disorder associated with repeated trauma at work is now so widespread amongst workers that many have diagnosed themselves before being medically assessed, often by means of the Internet. Surprisingly, however, a definite causal relationship has not yet been established for most occupations. Although the quality of research in this area is generally poor, CTS research studies are being used as the basis for acceptance of Workers Compensation claims, substantial expensive ergonomic workplace change and even workplace closures. The fact that the incidence of work-related musculoskeletal disorders has not changed despite these latter measures would suggest that a causal relationship is not proven and that some resources are being misdirected in CTS prevention and treatment. Method: A literature review of 64 articles on CTS was conducted. This included those articles most frequently cited as demonstrating the relationship between CTS and work. Results: Primary risk factors in the development of CTS are: being a woman of menopausal age, obesity or lack of fitness, diabetes or having a family history of diabetes, osteoarthritis of the carpometacarpal joint of the thumb, smoking, and lifetime alcohol intake. In most cases, work acts as the ,last straw' in CTS causation. Conclusion: Except in the case of work that involves very cold temperatures (possibly in conjunction with load and repetition) such as butchery, work is less likely than demographic and disease-related variables to cause CTS. To label other types of work as having caused CTS, therefore, would result in inappropriate allocation of resources. It would also relieve individuals of the responsibility of addressing correctable lifestyle factors and treatable illnesses such as obesity, diabetes, smoking and increased alcohol intake which may have contributed to their CTS more that their work. This results in both avoidable long-term health effects and ongoing costs to the community. [source] The record-breaking cold temperatures during the winter of 2009/2010 in the Northern Hemisphere,ATMOSPHERIC SCIENCE LETTERS, Issue 3 2010Dr Chunzai Wang Abstract In this study, we show that the record-breaking cold temperatures from North America to Europe and Asia during the period of 28 December 2009 to 13 January 2010 are associated with extremely negative values of the North Atlantic Oscillation (NAO) index, which produce northerly surface wind anomalies and cause the southward advection of the cold Arctic air. Corresponded to longer-term variations of Pacific and Atlantic Sea Surface Temperatures (SSTs), the downward trend of the NAO has occurred since the early 1990s. It is speculated that if the downward trend of the NAO continues, more frequent cold outbreaks and heavy snow are likely in the coming years. Published 2010 by John Wiley and Sons, Ltd. [source] | |||||||||||||||||||