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One Site (one + site)
Kinds of One Site Selected AbstractsEffects of environmental perturbations on abundance of subarctic plants after three, seven and ten years of treatmentsECOGRAPHY, Issue 1 2001Enrico Graglia Analyses of changes in vegetation were carried out after three, seven and ten years of fertilizer addition, warming and light attenuation in two subarctic, alpine dwarf shrub heaths. One site was just above the tree line, at ca 450 m a.s.l., and the other at a much colder fell-field at ca 1150 m altitude. The aim was to investigate how the treatments affected the abundance of different species and growth forms over time, including examinations of transient changes. Grasses, which increased in abundance by fertilizer addition, and cryptogams, which, by contrast, decreased by fertilizer addition and warming, were the most sensitive functional groups to the treatments at both sites. Nutrient addition exerted a stronger and more consistent effect than both shading and warming. Warming at the fell-field had slightly greater effect than at the warmer tree line with an increase in deciduous shrubs. The decreased abundance of mosses and lichens to fertilizer addition and/or warming was most likely an indirect treatment effect, caused by competition through increased abundance and overgrowth of grasses. Such changes in species composition are likely to alter decomposition rates and the water and energy exchange at the soil surface. We observed few, if any, transient effects of declining responses during the 10 yr of treatments. Instead, there were many cumulative effects of the treatments for all functional groups and many interactions between time and treatment, suggesting that once a change in community composition is triggered, it will continue with unchanged or accelerated rate for a long period of time. [source] Synthesis, X-ray Crystal Structures and Electrochemistry of (Indenyl)ruthenium Complexes Containing dppf and Heterocyclic Thiolato/Thione LigandsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2008Sin Yee Ng Abstract A number of (indenyl)ruthenium complexes containing dppf [1,1,-bis(diphenylphosphanyl)ferrocene] and heterocyclic thiolato/thione ligands have been synthesized. All the complexes were fully characterized by microanalytical and spectroscopic techniques, together with X-ray diffraction analyses for those containing the benzothiazolato (thiolato) and the thiadiazole (thione) ligands. Cyclic voltammetry (CV) experiments indicated that these complexes can be oxidized in three one-electron processes at positive potentials. Differences in chemical reversibility observed during variable-temperature CV experiments indicated that it was likely that the oxidation processes occurred at two electronically noncommunicating sites within the molecules. One site could be assigned as the oxidation of the Ru ion (two one-electron processes), whilst the second site was assigned as the oxidation of the dppf (one one-electron process). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] Distinguishing multiple chemotaxis Y protein conformations with laser-polarized 129Xe NMRPROTEIN SCIENCE, Issue 4 2005Thomas J. Lowery Abstract The chemical shift of the 129Xe NMR signal has been shown to be extremely sensitive to the local environment around the atom and has been used to follow processes such as ligand binding by bacterial periplasmic binding proteins. Here we show that the 129Xe shift can sense more subtle changes: magnesium binding, BeF3, activation, and peptide binding by the Escherichia coli chemotaxis Y protein. 1H- 15N correlation spectroscopy and X-ray crystallography were used to identify two xenon-binding cavities in CheY that are primarily responsible for the shift changes. One site is near the active site, and the other is near the peptide binding site. [source] Restoration of a Forest Understory After the Removal of an Invasive Shrub, Amur Honeysuckle (Lonicera maackii)RESTORATION ECOLOGY, Issue 2 2004Kurt M. Hartman Abstract The recruitment of native seedlings is often reduced in areas where the invasive Amur honeysuckle (Lonicera maackii) is abundant. To address this recruitment problem, we evaluated the effectiveness of L. maackii eradication methods and restoration efforts using seedlings of six native tree species planted within eradication and unmanipulated (control) plots. Two eradication methods using glyphosate herbicide were evaluated: cut and paint and stem injection with an EZ-Ject lance. Lonicera maackii density and biomass as well as microenvironmental characteristics were measured to study their effects on seedling growth and survivorship. Mean biomass of Amur honeysuckle was 361 ± 69 kg/ha, and density was 21,380 ± 3,171 plants/ha. Both eradication treatments were effective in killing L. maackii (, 94%). The injection treatment was most effective on large L. maackii individuals (>1.5 cm diameter), was 43% faster to apply than cutting and painting and less fatiguing for the operator, decreased operator exposure to herbicide, and minimized impact to nontarget vegetation. Deer browse tree protectors were used on half of the seedlings, but did not affect survivorship or growth. After 3 years, survival of native seedlings was significantly less where L. maackii was left intact (32 ± 3%) compared with the eradication plots (p < 0.002). Seedling survival was significantly different between cut (51 ± 3%) and injected (45 ± 3%) plots. Species had different final percent survival and rates of mortality. Species survival differed greatly by species (in descending order): Fraxinus pennsylvanica > Quercus muehlenbergii , Prunus serotina, Juglans nigra > Cercis canadensis > Cornus florida. Survivorship and growth of native seedlings was affected by a severe first-year drought and by site location. One site exhibited greater spring soil moisture, pH, percent open canopy, and had greater survivorship relative to the other site (55 ± 2 vs. 30 ± 2%). Overall, both L. maackii eradication methods were successful, but restorationists should be aware of the potential for differential survivorship of native seedlings depending on species identity and microenvironmental conditions. [source] Design of a Functional Nitric Oxide Reductase within a Myoglobin ScaffoldCHEMBIOCHEM, Issue 8 2010Valentin Köhler Dr. One site fits all: Yi Lu and co-workers have reported the conversion of sperm-whale myoglobin into a functional nitric oxide reductase. For this purpose, they designed a second metal binding site in the wild-type holo-protein and demonstrated NO reduction with the structurally characterized model, making thereby a significant contribution to the rapidly developing field of artificial metalloenzymes. [source] In-patient comparison of immediate and conventional loaded implants in mandibular molar sites within 12 monthsCLINICAL ORAL IMPLANTS RESEARCH, Issue 4 2008Güncü, M. Bar Abstract Objectives: The aim of this prospective clinical study was to evaluate the clinical outcomes of dental implants placed in the mandibular molar sites and immediately functionally restored compared with conventionally loaded controls in an in-patient study. Material and methods: Twenty-four dental implants were placed in 12 patients who had first molar loss bilaterally in the mandibular area. One site of the patient was determined as immediately loaded (IL) and the other side was conventionally loaded (CL). Resonance frequency analyses for implant stability measurements, radiographic examinations for marginal bone levels and peri-implant evaluations were performed during the clinical follow-up appointments within 12 months. Results: During the 12-month follow-up period, only one implant was lost in the IL group. The mean implant stability quotient values were 74.18±5.72 and 75.18±3.51 for Groups IL and CL at surgery, respectively, and the corresponding values were 75.36±5.88 and 75.64±4.84 at 1-year recall, respectively. The difference was not statistically significant between the two groups during the 12-month study period (P>0.05). When peri-implant parameters were evaluated, excellent peri-implant health was demonstrated during the 1-year observation period and all implants showed less than 1 mm of marginal bone resorption during the first year. Conclusions: In the present study, immediate functionally loading did not negatively affect implant stability, marginal bone levels and peri-implant health when compared with conventional loading of single-tooth implants. [source] Confronting Uncertainty and Missing Values in Environmental Value Transfer as Applied to Species ConservationCONSERVATION BIOLOGY, Issue 5 2010SONIA AKTER conservación de especies; error de transferencia; incertidumbre; transferencia de valor ambiental; valores de no uso Abstract:,The nonuse (or passive) value of nature is important but time-consuming and costly to quantify with direct surveys. In the absence of estimates of these values, there will likely be less investment in conservation actions that generate substantial nonuse benefits, such as conservation of native species. To help overcome decisions about the allocation of conservation dollars that reflect the lack of estimates of nonuse values, these values can be estimated indirectly by environmental value transfer (EVT). EVT uses existing data or information from a study site such that the estimated monetary value of an environmental good is transferred to another location or policy site. A major challenge in the use of EVT is the uncertainty about the sign and size of the error (i.e., the percentage by which transferred value exceeds the actual value) that results from transferring direct estimates of nonuse values from a study to a policy site, the site where the value is transferred. An EVT is most useful if the decision-making framework does not require highly accurate information and when the conservation decision is constrained by time and financial resources. To account for uncertainty in the decision-making process, a decision heuristic that guides the decision process and illustrates the possible decision branches, can be followed. To account for the uncertainty associated with the transfer of values from one site to another, we developed a risk and simulation approach that uses Monte Carlo simulations to evaluate the net benefits of conservation investments and takes into account different possible distributions of transfer error. This method does not reduce transfer error, but it provides a way to account for the effect of transfer error in conservation decision making. Our risk and simulation approach and decision-based framework on when to use EVT offer better-informed decision making in conservation. Resumen:,El valor de no uso (o pasivo) de la naturaleza es importante pero su cuantificación con muestreos pasivos consume tiempo y es costosa. En ausencia de estimaciones de estos valores, es probable que haya menos inversión en acciones de conservación que generen beneficios de no uso sustanciales, tal como la conservación de especies nativas. Para ayudar a superar decisiones respecto a la asignación de dólares para conservación que reflejan la carencia de estimaciones de los valores de no uso, estos valores pueden ser estimados indirectamente por la transferencia de valor ambiental (TVA). La transferencia de valor ambiental utiliza datos existentes o información de un sitio de estudio de tal manera que el valor monetario estimado de un bien ambiental es transferido a otro sitio. Un reto mayor en el uso de TVA es la incertidumbre sobre la señal y el tamaño del error (i.e., el porcentaje en que el valor transferido excede al valor actual) que resulta de la transferencia de estimaciones directas de los valores de no uso de un sitio de estudio a uno político, el sitio adonde el valor es transferido. Una TVA es más útil si el marco de toma de decisiones no requiere información muy precisa y cuando la decisión de conservación está restringida por tiempo y recursos financieros. Para tomar en cuenta la incertidumbre en el proceso de toma de decisiones, se puede seguir una decisión heurística que guie el proceso de decisión e ilustre sobre las posibles ramificaciones de la decisión. Para tomar en cuenta la incertidumbre asociada con la transferencia de valores de un sitio a otro, desarrollamos un método de riesgo y simulación que utiliza simulaciones Monte Carlo para evaluar los beneficios netos de las inversiones de conservación y que considera posibles distribuciones diferentes de la transferencia de error. Este método no reduce el error de transferencia, pero proporciona una manera para considerar el efecto del error de transferencia en la toma de decisiones de conservación. Nuestro método de riesgo y simulación y el marco de referencia basado en decisones sobre cuando utilizar TVA permiten la toma de decisiones en conservación más informadas. [source] Biological Sustainability of Live Shearing of Vicuña in PeruCONSERVATION BIOLOGY, Issue 1 2007CATHERINE TERESA SAHLEY Andes; conservación basada en comunidades; Vicugna vicugna Abstract:,The vicuña's (Vicugna vicugna) fiber is highly valued as an export product that is made into luxury fabric and clothing. The price of fiber in 2004 was $566/kg, which makes the fiber a potentially important source of income for Andean agropastoral communities and serves as an incentive to allow vicuña grazing on high-elevation Andean landscapes. It is presumed that a shorn vicuña has little value for poachers, so shearing vicuñas could serve as a disincentive to poaching. Thus, the supply of vicuña fiber may be sustainable if it is procured through live shearing, which should serve as a powerful conservation tool. We evaluated the effects of capture and shearing on the demography of vicuña in one site located in the Salinas Aguada Blanca Reserve, Arequipa, Peru, where vicuñas were captured and shorn in spring and then returned to the wild. We conducted fixed-width line-transect censuses from 1997 to 2003 of this population. We compared the proportion of young born to females that were shorn versus females that were unshorn for the 3 years in which shearing occurred. We evaluated the effect of capture and shearing on proportion of young born to shorn and unshorn females at a second site, Picotani, Puno. The wild population in Arequipa that underwent capture and shearing showed a steady increase in total population and average density between 1997 and 2003. No significant difference was found between the proportion of young per female for shorn and unshorn females at either site. We conclude that in spring, capture and live shearing of vicuñas can be biologically sustainable. Further research is needed to determine whether shearing during winter months is biologically sustainable. Resumen:,La fibra de vicuña (Vicugna vicugna) tiene gran valor como un producto de exportación que es transformado en tela y ropa de lujo. El precio de la fibra en 2004 era de $566/kg, lo que hace que la fibra sea una fuente de ingreso potencialmente importante para comunidades agropastoriles Andinas y servir como un incentivo para permitir el pastoreo de vicuñas en paisajes Andinos elevados. Se presume que una vicuña trasquilada tiene poco valor para cazadores furtivos, por lo que el trasquilado de vicuñas pudiera servir como un desincentivo para la caza furtiva. Por lo tanto, el abastecimiento de fibra de vicuña puede ser sustentable si se obtiene del trasquilado de animales vivos, y el trasquilado de animales vivos debería ser una poderosa herramienta de conservación. Evaluamos los efectos de la captura y trasquilado sobre la demografía de vicuñas en un sitio localizado en la Reserva Salinas Aguada Blanca, Arequipa, Perú, donde las vicuñas fueron capturadas y trasquiladas en primavera y liberadas. Realizamos censos de esta población en transectos lineales de ancho fijo de 1997 a 2003. Comparamos la proporción de crías de hembras trasquiladas con las de hembras no trasquiladas durante los 3 años en que ocurrió el trasquilado. Evaluamos el efecto de la captura y trasquilado sobre la proporción de crías de hembras trasquiladas y no trasquiladas en un segundo sitio, Picotani, Puno. La población silvestre en Arequipa que fue capturada y trasquilada mostró un incremento constante en la población total y la densidad promedio entre 1997 y 2003. No se encontró diferencia significativa entre la proporción de crías por hembra para hembras trasquiladas y no trasquiladas en ningún sitio. Concluimos que en la primavera, la captura y trasquilado de vicuñas vivas puede ser biológicamente sostenible. Se requiere más investigación para determinar si el trasquilado durante el invierno es biológicamente sostenible. [source] The distribution and prevalence of sponges in relation to environmental gradients within a temperate sea lough: vertical cliff surfacesDIVERSITY AND DISTRIBUTIONS, Issue 6 2000James J. Bell Abstract. The prevalence and distribution of sponges was surveyed on vertical cliff surfaces at Lough Hyne Marine Nature Reserve, Co. Cork, Ireland. The number of sponge species was recorded at 6-metre depth intervals at four sites within Lough Hyne, and at one site on the adjacent Atlantic coastline to examine differences in abundance and zonation patterns. Sites ranged from an exposed turbulent regime to sheltered, sedimented environments. Individual species showed different distributions and prevalence between sites and with increasing depth. Greatest differences were observed between the most- and least-disturbed sites. Distinct sponge zonation patterns were evident at all sites sampled. Twenty-five species were considered dominant at all five sites with the remaining 48 species considered rare. Only four of the 25 most-dominant species occurred at the site experiencing the most turbulent flow conditions, whereas 12 species were found at the site of unidirectional fast flow. At sites of moderate to slight water movement and high sedimentation, between 18 and 24 of the most dominant species were present. Encrusting forms constituted high proportions of sponge communities at all five sites sampled (although consisting of different species). At sites of turbulent and unidirectional fast flow massive forms also dominated whereas at the least turbulent sites, where sedimentation was high, arborescent sponges were abundant. Few species showed exclusive distribution to a single depth and site, but there was some degree of correlation between species distributions and abiotic factors such as sedimentation rate and flow regimes. Sponge distributions and densities are discussed with respect to the suitability of species' morphologies to particular environments, intra-specific and inter-specific competition and physiological adaptations that enable them to survive in different habitats. [source] Edaphic niche differentiation among Polybotrya ferns in western Amazonia: implications for coexistence and speciationECOGRAPHY, Issue 3 2006Hanna TuomistoArticle first published online: 22 FEB 200 To study the degree of edaphic specialization in Amazonian plants, the distribution patterns of seven species of Polybotrya ferns were studied in 109 sites in a climatically uniform area of northwestern Amazonia (Colombia, Ecuador and northern Peru). The two most abundant species of Polybotrya were found in about two-thirds of the sites with almost 7000 individuals each, the rarest species occurred in just one site with 40 individuals. Each of the seven species appeared to have a unique realised niche, when niche dimensions were defined by gradients in soil texture, soil cation content, and inundation. The species also differed in how broadly or narrowly they were distributed along each gradient. Some species were practically never found in the same sites, whereas others co-occurred with a high frequency, in spite of showing clearly different abundance patterns among sites. A single site only contains a small part of the edaphic variation present in the landscape, and a small proportion of any species' niche space, so broad-scale studies are needed to adequately describe and compare species' niches and to assess to what degree niche differences promote species coexistence. The distribution patterns in Polybotrya are consistent with, but do not prove, that ecological speciation may have been important in the radiation of the genus. If such a pattern is found to be common in other Amazonian plants, this would indicate that each evolutionary lineage has adapted to the available habitats largely independently of the others. [source] Interpopulation differences in the mandible size of the coastal tiger beetle Lophyridia angulata associated with different sympatric speciesENTOMOLOGICAL SCIENCE, Issue 3 2004Aya SATOH Abstract The coastal tiger beetle Lophyridia angulata (Fabricius) co-occurs with one or two tiger beetle species at any one locality (in a sandy beach habitat) along the Japan Sea coast of Honshu, from eastern to southern Kyushu, and on Tanega-shima, an island south of Kyushu, in Japan. Lophyridia angulata displays sexual dimorphism in mandible length (the mandible is longer in females), and shows large interpopulation differences in mandible size. We analyzed variation in mandible length between L. angulata populations associated with three different sympatric species, and examined morphological differences that may have resulted from interaction with these other species. Lophyridia angulata showed a significant size shift towards larger mandibles in a population that co-occurred with Cicindela lewisii, which has a similar mandible length to that of L. angulata, as compared to a neighboring population of L. angulata that co-occurred with another species. This pattern may be interpreted as a type of character displacement associated with food resource competition. Males in L. angulata populations co-occurring with Chaetodera laetescripta showed little variation in mandible length, as compared to other populations. These males may experience some pressure from C. laetescripta and from conspecific females. We found no significant changes in mandible length or in size variation of L. angulata before and 20 years after the extinction of Abroscelis anchoralis at one site historically co-inhabited by both species; that is, we did not detect a character release over the 20 years. [source] Evidence for a Role of the Parafascicular Nucleus of the Thalamus in the Control of Epileptic Seizures by the Superior ColliculusEPILEPSIA, Issue 1 2005Karine Nail-Boucherie Summary:,Purpose: The aim of this study was to investigate whether the nucleus parafascicularis (Pf) of the thalamus could be a relay of the control of epileptic seizures by the superior colliculus (SC). The Pf is one of the main ascending projections of the SC, the disinhibition of which has been shown to suppress seizures in different animal models and has been proposed as the main relay of the nigral control of epilepsy. Methods: Rats with genetic absence seizures (generalized absence epilepsy rat from Strasbourg or GAERS) were used in this study. The effect of bilateral microinjection of picrotoxin, a ,-aminobutyric acid (GABA) antagonist, in the SC on the glutamate and GABA extracellular concentration within the Pf was first investigated by using microdialysis. In a second experiment, the effect of direct activation of Pf neurons on the occurrence of absence seizures was examined with microinjection of low doses of kainate, a glutamate agonist. Results: Bilateral injection of picrotoxin (33 pmol/side) in the SC suppressed spike-and-wave discharges for 20 min. This treatment resulted in an increase of glutamate but not GABA levels in the Pf during the same time course. Bilateral injection of kainate (35 pmol/side) into the Pf significantly suppressed spike-and-wave discharges for 20 min, whereas such injections were without effects when at least one site was located outside the Pf. Conclusions: These data suggest that glutamatergic projections to the Pf could be involved in the control of seizures by the SC. Disinhibition of these neurons could lead to seizure suppression and may be involved in the nigral control of epilepsy. [source] Habitat selection as a source of inter-specific differences in recruitment of two diadromous fish speciesFRESHWATER BIOLOGY, Issue 11 2008ROBIN HALE Summary 1For aquatic species with highly dispersive offspring, the addition of new individuals into an area (recruitment) is a key process in determining local population size so understanding the causes of recruitment variability is critical. While three general causative mechanisms have been identified (the supply of individuals, habitat selection and mortality), we have a limited understanding of how variation in each is generated, and the consequences this may have for the spatial and temporal distribution of recruits. 2We examined whether active habitat selection during settlement could be the cause of variability in populations of two diadromous fish species using a field survey and laboratory-based choice experiments. If larval behaviour is important, we predicted there would be inter-specific differences in abundance between sites during the survey, and that larvae would prefer water collected from sites with higher conspecific abundances during the experiments. 3During the field survey, significant differences were detected between two rivers (the Cumberland and Grey), with one species (Galaxias maculatus) found in higher abundances at one site (the Cumberland River) while comparable numbers of a closely related species (Galaxias brevipinnis) were caught at both sites. Laboratory choice experiments were conducted to determine whether larval preferences during settlement could be the cause of these differences. G. maculatus larvae showed a preference for freshwater over saltwater, indicating that the fish may be responding to reduced salinities around river mouths during settlement. The results of a second experiment were consistent with the notion that larval preferences could be the mechanism driving differences in the populations of the two rivers, with G. maculatus preferring water collected from the Cumberland River while G. brevipinnis did not prefer water from either river. 4These results demonstrate that active habitat selection may be important in establishing spatial patterns of larvae at settlement, and that multiple cues are likely to be involved. This study also demonstrates that the behaviours exhibited by individuals can strongly influence the structure and dynamics of populations of aquatic species with complex life cycles. [source] Population structure and its implications for conservation of the great silver beetle Hydrophilus piceus in BritainFRESHWATER BIOLOGY, Issue 11 2007TREVOR J. C. BEEBEE Summary 1. The great silver water beetle Hydrophilus piceus is one of the largest aquatic insects in Europe. In Britain it is rare and endangered, and confined to a small number of low-lying marshes. Very little is known about the beetle populations in any of these areas, or the connectivity between them. 2. To investigate the population structure of H. piceus in Britain, four polymorphic microsatellite loci were identified and characterized. The genome of this beetle seems to have few microsatellites but contains a high proportion of a larger repeated sequence. 3. All six of the main British populations (Somerset, Lewes, Pevensey, Romney, North Kent and Norfolk) showed substantial genetic diversity at the microsatellite loci. However, estimates of effective population size at one site (Pevensey) were remarkably low, at <10 adults for the period 2004,05. 4. Most of the genetic diversity was partitioned within rather than among the populations, although there was, nevertheless, significant genetic sub-structuring. Almost all population pairwise Fst estimates were significantly different from zero, and there was a clear isolation-by-distance effect. Assignment tests and cluster analyses demonstrated interpopulation relationships largely consistent with their geographical separations. 5. Hydrophilus disperses by flight, and records from moth traps indicated that there was no month in which the beetles never flew, but that flight activity was highest in the spring. 6. The genetic data highlight the need to maintain or regenerate habitat connectivity within flying distance for H. piceus, and to sustain large areas of suitable breeding marshes. [source] Comparison of the maritime Sites and Monuments Record with side-scan sonar and diver surveys: A case study from Rathlin Island, IrelandGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 5 2002Rory Quinn Rathlin Island, off the north coast of Ireland, has a history of settlement and seafaring from the Late Mesolithic period to the present day. The maritime Sites and Monuments Record (SMR) for Rathlin indicates many wrecking incidents. In 1999, a reconnaissance side-scan sonar survey confirmed the presence of 46 targets of possible archaeological potential around Rathlin Island. Thirteen of these anomalies were positively identified as shipwrecks. Of the remaining 33 targets, nine were dived on in order to ground-truth the geophysical data. A successful and rapid methodology of ground-truthing side-scan sonar data for archaeological purposes was developed. The results confirmed the presence of a Danforth Anchor at one site, while the remaining anomalies were identified as geological features. The results from the side-scan survey and diver-truthing exercise enhanced the existing maritime SMR. © 2002 Wiley Periodicals, Inc. [source] Surface Heat Balance and Spatially Distributed Ablation Modelling at Koryto Glacier, Kamchatka Peninsula, RussiaGEOGRAFISKA ANNALER SERIES A: PHYSICAL GEOGRAPHY, Issue 4 2004Keiko Konya Abstract To investigate the characteristics of ablation at Koryto Glacier, a mountain glacier under maritime climate in Kamchatka Peninsula, Russia, we made field observations from August to early September 2000. At a site near the equilibrium line, the 31-day average net radiation, sensible heat flux, and latent heat flux were 43, 59 and 31 W,2, respectively. We developed a new distributed ablation model, which only needs measurements of air temperature and global radiation at one site. Hourly ablation rates at this site obtained by the energy balance method are related to measured air temperature and global radiation by linear multiple regression. A different set of multiple regression coefficients is fitted for snow and ice surfaces. Better estimates of ablation rate can be obtained by this approach than by other temperature index models. These equations are then applied to each grid cell of a digital elevation model to estimate spatially distributed hourly melt. Air temperature is extrapolated using a constant temperature lapse rate and global radiation is distributed considering topographic effects. The model enables us to calculate the hourly spatial distribution of ablation rates within the glacier area and could well provide a realistic simulation of ablation over the whole glacier. [source] Ground Water Transfer Initiates Complete Reductive Dechlorination in a PCE-Contaminated AquiferGROUND WATER MONITORING & REMEDIATION, Issue 3 2007R. Lookman We conducted a field test to investigate whether ground water transfer from one site (showing complete natural reductive dechlorination of chlorinated ethenes to ethene) could induce full reductive dechlorination at another site polluted with tetrachloroethene and its partial dechlorination products trichloroethene and cis -dichloroethene (cDCE). Addition of electron donor (lactate) at the test site established low redox conditions but did not stimulate further dechlorination past cDCE. After transferring 2 m3 of ground water from the first site to the test site, full dechlorination commenced and high levels of ethene were measured to distances up to 6 m downstream of the injection location within 7 months. Ground water samples from monitoring wells were analyzed before and after inoculation of the test site for the presence of Dehalococcoides species (16S ribosomal RNA) and vinyl chloride reductase (vCRA) genes using the polymerase chain reaction. These tests showed that Dehalococcoides species were present both before and after ground water transfer, while vCRA genes were detected at the test site only after ground water transfer. The vCRA genes were detected in ground water samples collected 6 m downstream of the injection locations 7 months after ground water transfer, suggesting that the microorganisms carrying the dehalogenase genes were effectively transported in the aquifer. [source] Ground Water Chlorinated Ethenes in Tree Trunks: Case Studies, Influence of Recharge, and Potential Degradation MechanismGROUND WATER MONITORING & REMEDIATION, Issue 3 2004Don A. Vroblesky Trichloroethene (TCE) was detected in cores of trees growing above TCE-contaminated ground at three sites: the Carswell Golf Course in Texas, Air Force Plant PJKS in Colorado, and Naval Weapons Station Charleston in South Carolina. This was true even when the depth to water was 7.9 m or when the contaminated aquifer was confined beneath ,3 m of clay. Additional ground water contaminants detected in the tree cores were cis,1,2-dichloroethene at two sites and tetrachloroethene at one site. Thus, tree coring can be a rapid and effective means of locating shallow subsurface chlorinated ethenes and possibly identifying zones of active TCE dechlorination. Tree cores collected over time were useful in identifying the onset of ground water contamination. Several factors affecting chlorinated ethene concentrations in tree cores were identified in this investigation. The factors include ground water chlorinated ethene concentrations and depth to ground water contamination. In addition, differing TCE concentrations around the trunk of some trees appear to be related to the roots deriving water from differing areas. Opportunistic uptake of infiltrating rainfall can dilute prerain TCE concentrations in the trunk. TCE concentrations in core headspace may differ among some tree species. In some trees, infestation of bacteria in decaying heartwood may provide a TCE dechlorination mechanism within the trunk. [source] Adult Emergency Department Patients with Sickle Cell Pain Crisis: A Learning Collaborative Model to Improve Analgesic ManagementACADEMIC EMERGENCY MEDICINE, Issue 4 2010Paula Tanabe PhD Abstract Objectives:, The objectives were to report the baseline (prior to quality improvement interventions) patient and visit characteristics and analgesic management practices for each site participating in an emergency department (ED) sickle cell learning collaborative. Methods:, A prospective, multisite longitudinal cohort study in the context of a learning-collaborative model was performed in three midwestern EDs. Each site formed a multidisciplinary team charged with improving analgesic management for patients with sickle cell disease (SCD). Each team developed a nurse-initiated analgesic protocol for SCD patients (implemented after a baseline data collection period of 3.5 months at one site and 10 months at the other two sites). All sites prospectively enrolled adults with an acute pain crisis and SCD. All medical records for patients meeting study criteria were reviewed. Demographic, health services, and analgesic management data were abstracted, including ED visit frequency data, ED disposition, arrival and discharge pain score, and name and route of initial analgesic administered. Ten interviews per quarter per site were conducted with patients within 14 days of their ED discharge, and subjects were queried about the highest level of pain acceptable at discharge. The primary outcome variable was the time to initial analgesic administration. Variable data were described as means and standard deviations (SDs) or medians and interquartile ranges (IQR) for nonnormal data. Results:, A total of 155 patients met study criteria (median age = 32 years, IQR = 24,40 years) with a total of 701 ED visits. Eighty-six interviews were conducted. Most patients (71.6%) had between one and three visits to the ED during the study period. However, after removing Site 3 from the analysis because of the short data enrollment period (3.5 months), which influenced the mean number of visits for the entire cohort, 52% of patients had between one and three ED visits over 10 months, 21% had four to nine visits, and 27% had between 10 and 67 visits. Fifty-nine percent of patients were discharged home. The median time to initial analgesic for the cohort was 74 minutes (IQR = 48,135 minutes). Differences between choice of analgesic agent and route selected were evident between sites. For the cohort, 680 initial analgesic doses were given (morphine sulfate, 42%; hydromorphone, 46%; meperidine, 4%; morphine sulfate and ibuprofen or ketorolac, 7%) using the following routes: oral (2%), intravenous (67%), subcutaneous (3%), and intramuscular (28%). Patients reported a significantly lower targeted discharge pain score (mean ± SD = 4.19 ± 1.18) compared to the actual documented discharge pain score within 45 minutes of discharge (mean ± SD = 5.77 ± 2.45; mean difference = 1.58, 95% confidence interval = .723 to 2.44, n = 43). Conclusions:, While half of the patients had one to three ED visits during the study period, many patients had more frequent visits. Delays to receiving an initial analgesic were common, and post-ED interviews reveal that sickle cell pain patients are discharged from the ED with higher pain scores than what they perceive as desirable. ACADEMIC EMERGENCY MEDICINE 2010; 17:399,407 © 2010 by the Society for Academic Emergency Medicine [source] Selective hippocampal damage in rhesus monkeys impairs spatial memory in an open-field test,HIPPOCAMPUS, Issue 7 2004Robert R. Hampton Abstract The hippocampus is critical for remembering locations in a wide variety of species, including humans. However, recent findings from monkeys following selective hippocampal lesions have been equivocal. To approximate more closely the situations in which rodents and birds are tested, we used a spatial memory task in which rhesus monkeys (Macaca mulatta) moved about freely in a large room, on a tether. We used MRI-guided stereotaxic surgery to produce selective hippocampal lesions in five monkeys, and retained five unoperated control monkeys. In the study phase of each trial of the matching-to-location task, monkeys found food in one site in an array of identical foraging sites. During the test, which occurred after a delay, monkeys could return to the site where the food had been found during study to obtain more food. In Experiment 1, normal monkeys showed a small significant tendency to return directly to a site where they had previously found food that day. Operated monkeys showed no such matching tendency. In Experiment 2, further training produced reliable matching-to-location performance in both groups at short delays, but monkeys with selective hippocampal lesions rapidly forgot the location of the food. In Experiment 3, we tested whether monkeys used a "cognitive map" to encode the location of the hidden food, by requiring them to relocate the food from a starting location different from that used during study. As a group, monkeys were more accurate than expected by chance, indicating that they did encode the rewarded location with respect to allocentric landmarks; however, both groups of monkeys were significantly worse at relocating the food when required to approach from a different location. In Experiment 4, probe trials using symmetrical test arrays found no evidence for egocentric coding of the rewarded location. © 2004 Wiley-Liss, Inc. [source] Use of caesium-137 data to evaluate SHETRAN simulated long-term erosion patterns in arable landsHYDROLOGICAL PROCESSES, Issue 10 2004Y. Norouzi Banis Abstract The caesium-137 method of quantifying soil erosion is used to provide field data for validating the capability of the SHETRAN modelling system for predicting long-term (30-year) erosion rates and their spatial variability. Simulations were carried out for two arable farm sites (area 3,5 ha) in central England for which average annual erosion rates of 6·5 and 10·4 t ha,1 year,1 had already been determined using caesium-137 measurements. These rates were compared with a range of simulated values representing the uncertainty in model output derived from uncertainty in the evaluation of model parameters. A successful validation was achieved in that the simulation range contained the measured rate at both sites, whereas the spatial variability was reproduced excellently at one site and partially at the other. The results indicate that, as the caesium-137 technique measures the erosion caused by all the processes acting at a site, it is relevant to hydrologically based models such as SHETRAN only if erosion by wind, agricultural activities and other processes not represented in the model are insignificant. The results also indicate a need to reduce the uncertainty in model parameter evaluation. More generally, the caesium-137 technique is shown to provide field data that improve the severity of the validation procedure (accounting for internal as well as outlet conditions) and that add spatial variability to magnitude as a condition for identifying unrealistic parameter sets when seeking to reduce simulation uncertainty. Copyright © 2004 John Wiley & Sons, Ltd. [source] An examination of skulls from two British sites for possible evidence of scurvyINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 4 2003M. Melikian Abstract Skulls and mandibles from the Romano-British site of Poundbury, Dorset and a medieval site at Abingdon in Oxfordshire were examined for porosity which has been considered to be indicative of the presence of scurvy. In addition, a number of skulls from various locations in Peru were examined. Virtually all the skulls had porosity at at least one site and in all cases the palate was most frequently affected. The rank order of affected sites showed some differences between the three samples but the most striking change was the frequency with which the cranial vault and maxilla were affected in the Peruvian skulls compared with the British. The differences were not statistically significant, however. None of the appearances was consistent with those of known cases of infantile scurvy and we doubt whether scurvy can be diagnosed on the basis of porosity in the skull and mandible unless it conforms to recognized clinical patterns. Copyright © 2003 John Wiley & Sons, Ltd. [source] Evaluating outpatient pharmacy services: a literature review of specialist heart failure servicesINTERNATIONAL JOURNAL OF PHARMACY PRACTICE, Issue 1 2006Tracey-Lea Hargraves Pharmacist (formerly) Objective To identify appropriate methods to evaluate a specialist pharmacy service for heart failure patients in an ambulatory care setting. Method An extensive literature review was undertaken to identify the published data on evaluative studies of specialist pharmacy services, including those directed at heart failure patients in an ambulatory care model of service provision. Key findings Six studies were identified evaluating outpatient pharmacy services for heart failure. The pharmacy services provided in these settings were not well defined. The impact of the pharmacist was compared to ,usual care', that is care delivered without a pharmacist, by either a prospective randomised controlled trial (RCT), or before and after studies. In most cases the service was delivered by one pharmacist at one site. Services were primarily targeted at patients and focused on medication and lifestyle education, adverse drug reaction monitoring, and compliance/adherence. In all studies, there was a trend for improvement in the outcomes measured. Different study endpoints were examined, including process indicators such as compliance and outcome measures such as morbidity (clinical), quality of life (humanistic), and hospital admissions (economic). The ideal evaluative study would be an adequately powered, prospective, randomised controlled trial, comparing the effect of the pharmacist service to usual care (without the specified pharmacy service). Appropriate study endpoints including process indicators and outcome measures are needed. Identification of specific components and the extent of the service that would provide the most benefit to selected patient groups would be of interest. Conclusions Specialist ambulatory care pharmacy services have not been well defined or evaluated in the literature. Limited randomised controlled data exist. [source] Biogeography and microhabitat variation in temperate algal-invertebrate symbioses: zooxanthellae and zoochlorellae in two Pacific intertidal sea anemones, Anthopleura elegantissima and A. xanthogrammicaINVERTEBRATE BIOLOGY, Issue 2 2000David Secord Abstract. Temperate sea anemones in the genus Anthopleura are unique among cnidarians in harboring two phylogenetically distinct symbiotic algae, zooxanthellae (golden-brown dinophytes, Symbiodinium) and zoochlorellae (green chlorophytes). To determine whether their physiological differences generate patterns in anemone habitat and biogeographic distribution, we sampled symbiotic algae in the small clonal A. elegantissima and the large solitary A. xanthogrammica at 8 field sites (and the other large solitary Anthopleura species at one site) spanning 18° of latitude along 2500 km of the Pacific coast of North America. We found that zoochlorellae predominate in low intertidal habitats and northerly latitudes and in A. xanthogrammica, while zooxanthellae constitute the majority of symbionts in high intertidal habitats and more southerly latitudes and in A. elegantissima. These data are consistent with published predictions based on photosynthetic efficiency of the two algae under varied temperature and light regimes in the laboratory. This anemone-algal system provides a potential biological signal of benthic intertidal communities' responses to El Niño events and long-term climate changes in the Pacific. [source] Leaf Carbon Isotope Discrimination and its Relation with Qualitative Root Traits and Harvest Index in Sugar Beet (Beta vulgaris L.)JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 5 2003J. T. Tsialtas Abstract Twenty commercial sugar beet varieties were grown at two sites in central Greece during the 2001 growing season (March to October), in a completely randomized block design with three replications. Carbon isotope discrimination (,) in sugar beet leaves was found to be affected by site and marginally by variety. No relation was found between fresh root yield and ,, but significant correlations were found between , and sucrose content (positive) and between , and root ,-amino-N (negative). Also, the harvest index, determined at one site, was negatively correlated with ,. [source] Musculoskeletal Pain and Risk for Falls in Older Disabled Women Living in the CommunityJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 4 2002Suzanne G. Leveille PhD OBJECTIVES: To determine whether musculoskeletal pain increased risk for falls in older women with disabilities. DESIGN: Prospective population-based cohort study. SETTING: The city and county of the eastern area of Baltimore. PARTICIPANTS: One thousand two women aged 65 and older, participants in the Women's Health and Aging Study, representing the one-third of older women who were living at home with disabilities, followed semiannually for 3 years beginning in 1991. MEASUREMENTS: Pain was categorized into four groups according to severity and location. Widespread pain was defined as pain in the upper and lower extremities and in the axial skeletal region, with moderate to severe pain in at least one region (, 4 on a 10-point numeric rating scale, 10 = excruciating pain). Moderate to severe lower extremity pain that did not meet criteria for widespread pain was the next category. The reference category was no pain or mild pain in one site. The additional category of "other pain" was pain that did not fit into the other three groups. The occurrence of falls and fall-related injuries were assessed at each interview. RESULTS: Of the 940 women who participated in at least one follow-up examination, 39% fell in first year; of the survivors, 36% fell in Year 2, and 39% in Year 3. After adjusting for several major risk factors for falls, women with widespread pain had an increased likelihood of falling during follow-up (adjusted odds ratio (AOR) = 1.66, 95% confidence interval (CI) = 1.25,2.21) compared with those with no or mild pain in only one musculoskeletal site. Women who had other musculoskeletal pain but not widespread pain or lower extremity pain also had an increased risk of falls (AOR = 1.36, 95% CI = 1.02,1.82). Among women with musculoskeletal pain, risk for falls was lower in those who used daily analgesic medication. Risk for recurrent falls and self-reported fractures due to falls was also elevated in women with musculoskeletal pain, most consistently in women with widespread pain. CONCLUSIONS: Musculoskeletal pain, particularly widespread pain, is a substantial risk factor for falls in older women with disabilities. These findings add an important dimension to our understanding of the multifactorial processes leading to falls in older persons. J Am Geriatr Soc 50:671,678, 2002. [source] Dynamics of common wasps in New Zealand beech forests: a model with density dependence and weatherJOURNAL OF ANIMAL ECOLOGY, Issue 4 2002N. D. Barlow Summary 1Nest densities of the common wasp ( Vespula vulgaris (L.)) were monitored at six sites for 13 years in the honeydew-rich southern beech ( Nothofagus spp.) forests of New Zealand's South Island. 2Densities of wasp nests were among the highest in the world, up to 30 ha ,1 , and at any one site varied approximately twofold over the study period. 3Strong but not overcompensating density dependence was identified, together with a negative effect of spring rainfall. 4The density dependence appeared to act from the number of autumn queens produced during one year to the number of mature (autumn) nests the next year, rather than through variations in queen production per nest. The same stage was also responsible for most of the variability in autumn nest numbers from year to year, with queen production per nest contributing less. 5Yearly changes in nest density could be summarized by a simple Ricker model including both density dependence and weather, thereby incorporating both previous hypotheses for the determination of wasp abundance. [source] Isolation of entomopathogenic fungi from the soil and their pathogenicity to two fruit fly species (Diptera: Tephritidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 9-10 2008P. Sookar Abstract The occurrence of deuteromycetous entomopathogenic fungi was determined by examining 224 soil samples from 19 locations in three climatic zones of Mauritius. Three sites were sampled per location: one site under vegetables cultivation, one site under sugar cane plantation and one natural site each within 1 km of each other. Soil samples were baited with the waxmoth larvae Galleria mellonella L. and incubated in the dark at 15, 20, 25 or 30°C for 7, 14 and 21 days. Entomopathogenic fungi were isolated from 77 out of 224 (38.6%) soil samples. Metarhizium anisopliae was isolated from 42 (18.8%) samples, Beauveria bassiana from 24 (10.7%), Metarhizium spp. and Paecilomyces fumosoroseus from 5 (2.2%) each and Beauveria spp. from 1 (0.4%). It was observed that M. anisopliae was isolated more frequently from soils under vegetables as compared to soils under sugarcane or habitat with natural vegetation. Beauveria bassiana was isolated more frequently at the lowest incubation temperature (15°C) while M. anisopliae isolates were recovered more frequently at higher temperatures (25 and 30°C). The pathogenicity of seven isolates of M. anisopliae, five isolates of B. bassiana and two isolates of P. fumosoroseus towards the adults of Bactrocera zonata and Bactrocera cucurbitae was tested by topical application of conidial suspension of 1 × 106 conidia/ml. All the isolates tested were pathogenic to the two fruit fly species. Mortality of B. zonata varied between 12.0 and 98.0% and between 2.0 and 94.0% in B. cucurbitae at 5 days post-treatment. Our results suggest that entomopathogenic fungi present locally, could be integrated for the control of B. zonata and B. cucurbitae. [source] Safe and Effective Ablation of Atrial Fibrillation: Importance of Esophageal Temperature Monitoring to Avoid Periesophageal Nerve Injury as a Complication of Pulmonary Vein IsolationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 1 2009TAISHI KUWAHARA M.D. Introduction: Catheter ablation on the left atrial posterior wall has been reported to potentially damage the esophagus or periesophageal vagal nerve. The aim of this study was to evaluate the efficacy of esophageal temperature monitoring (ETM) in preventing esophageal or periesophageal vagal nerve injury in patients with atrial fibrillation (AF) undergoing pulmonary vein (PV) isolation. Methods: This study included 359 patients with drug-refractory AF who underwent extensive PV isolation. The first 152 patients were treated without ETM (non-ETM) and the last 207 with ETM. In the ETM group, the esophageal temperature (ET) was measured with a deflectable temperature probe that was placed close to the ablation electrode, and the radiofrequency energy applications were stopped when the ET reached 42°C. Results: In all patients in the ETM group, the ET increased to 42°C in at least one site by 28 ± 14 seconds, mostly along the right side of the left PVs, especially near the left inferior PV. Less energy (6.3 ± 1.9 × 104 J) was required for PV isolation in the ETM group than that in the non-ETM (6.8 ± 1.9 ×104 J, P = 0.03). Gastric hypomotility owing to periesophageal nerve damage was observed in three patients in the non-ETM group, but in none in the ETM (P = 0.02). The recurrence rates of AF did not differ between the two groups (non-ETM, 29%; ETM, 27%). Conclusion: Titration of the duration of the ablation energy delivery while monitoring the ET could prevent periesophageal nerve injury due to the AF ablation, without decreasing the success rate of maintaining sinus rhythm. [source] Relationship between betel quid additives and established periodontitis among Bangladeshi subjectsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 1 2008Rahena Akhter Abstract Aim: To determine the relationship between betel quid chewing additives and established periodontitis in Bangladeshi subjects. Material and Methods: A total of 864 subjects participated in this study. Among them, 140 pairs of sex- and age-matched case subjects and control subjects were selected. A case was defined as a person who had at least two sites with a clinical attachment level (CAL)6 mm and at least one site with probing depth (PD)5 mm. Subjects who did not fulfill these criteria were considered as controls. Information on sociodemographic variables, psychological stress, dental health behaviour, smoking and betel quid chewing habits was obtained. Results: Multiple logistic regression analysis showed that current betel quid chewers had greater probabilities of having established periodontal disease than did non-chewers (odds ratio=3.97, p<0.05). Mean PD, mean CAL, mean percentage of bleeding on probing and number of missing teeth were significantly higher in chewers of betel quid with tobacco and masala than in chewers of betel quid without such additives adjusting for age, sex, smoking habit, body mass index, dental visit pattern, stress and plaque index. Higher frequency and longer duration of betel quid chewing showed a significant relation to an increase in periodontal parameters. Conclusion: The results indicate that betel quid additives might significantly enhance periodontitis in the population studied. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||