1,803 research outputs found

    Transmissivity of carbon monoxide in the 2.3 microns band region

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    Line strengths and self and nitrogen broadened half-widths have been determined from high resolution spectroscopic measurements of selected lines in the 2.3 micrometer band region of CO. The CO 0-2 total band strength is estimated to be 2.086 + or - 0.146 cm/1 (ATM-cm)/1 STP which is higher than most previously reported values. The line half-widths are also generally higher than those in the literature

    Coastal Bluff Retreat at Big Lagoon, California

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    Big Lagoon, located 30 miles north of Eureka, California is formed behind a bay barrier built across the mouth of a drowned river valley. To the south of the bay the beach follows rising wave cut slightly cemented sand and gravel sea cliffs and terminates at the south end of Agate Beach. The retreat of these sea cliffs and its effect on property development along the top of the cliff is the focus of the paper. Measurements of bluff retreat in this area have been documented extensively from November 1941 to March 1986 through ground surveys and air photos. Review of the data indicates that the retreat rate is not constant along the cliff but has either been decreasing or remaining the same over the last 45 years. Using information on the rate of retreat, a method is developed to predict the cliff erosion in the future

    Site Specific Seismic/Geologic Hazards Risk Zoning

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    A site specific risk zoning study was conducted on a Junior College Campus near Eureka, California, USA to evaluate the potential seismic/geologic hazards due to the presence of a 1 km wide low angle thrust fault system. Issues addressed to determine the level of risk at any location on the campus include: land sliding, earthquake ground shaking, ground surface rupture and deformation, lateral spreading, liquefaction, differential settlement, and tsunamis. Based on these potential hazards, a micro-zonation model was developed based on 13 different zones and 5 levels of risk. Information for use in this model was collected using a combination of paleo seismic trenches, geophysical surveys and soil borings. This information was then combined to develop a map of risk zones within the campus. This map provides site specific land use recommendations to assist the college in locating appropriate sites for future campus expansion

    Population Characteristics, Morphometry, and Growth of Harvested Gray Wolves and Coyotes in Alaska

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    Few concurrent studies exist of sympatric gray wolf (Canis lupus) and coyote (C. latrans) harvest at far northern latitudes. Moreover, no studies explicitly examine effects of concurrent harvest on phenotypes of wolves and coyotes. We documented changes in sex and age characteristics and morphology of gray wolves and coyotes harvested by hunters near Ptarmigan Lake, east-central Alaska, USA, between 1998 and 2001. We hypothesized that the harvest would result in larger, heavier canids, reduce densities, and increase young to adult ratios in both wolves and coyotes. We generated von Bertalanffy growth curves indicating that wolves and coyotes of both sexes increased in length or weight until 2 or 3 years old. No significant changes in either mean length or weight or length to weight ratios occurred during the 3-year study, except that coyote mean length was longer over the last winter of study. Catch-per-unit effort (CPUE) for wolves ranged from 0.061 to 0.112 killed/day and for coyotes from 0.552 to 0.11 killed/day over the study. CPUE indicated that coyotes but not wolves declined in abundance. Changes in male to female and young to adult ratios did not differ significantly for either canid. We posit that coyote populations were disproportionately affected by the conflation of the severe Arctic environment and sustained harvest. Our findings will be beneficial for managing sympatric canid populations and for understanding demographic responses to density-dependent processes in wolves and coyotes, especially at far northern latitudes.Il existe peu d’études concomitantes sur la récolte du loup gris (Canis lupus) et du coyote (C. latrans) sympatriques dans les hautes latitudes nordiques. Par ailleurs, aucune étude n’examine explicitement les effets de la récolte concomitante sur les phénotypes des loups et des coyotes. Nous avons documenté les changements sur le plan de la morphologie et des caractéristiques du sexe et de l’âge des loups gris et des coyotes récoltés par les chasseurs à proximité du lac Ptarmigan, dans le centre-est de l’Alaska, aux États-Unis, de 1998 à 2001. Nous avons formulé l’hypothèse voulant que la récolte donnerait lieu à des canidés plus gros et plus lourds, réduirait les densités et augmenterait les rapports entre jeunes et adultes, tant chez les loups que chez les coyotes. Nous avons produit des courbes de croissance de von Bertalanffy selon lesquelles la longueur ou le poids des loups et des coyotes des deux sexes augmentait jusqu’à l’âge de deux ou trois ans. Sur le plan de la longueur ou du poids moyen, ou des rapports moyens entre la longueur et le poids, aucun changement important n’a été enregistré pendant l’étude de trois ans, sauf que la longueur moyenne du coyote était plus grande au cours du dernier hiver de l’étude. Pour le loup, la capture par unité d’effort (CPUE) variait de 0,061 à 0,112 bête tuée/jour, tandis que pour le coyote, elle variait de 0,552 à 0,11 bête tuée/jour dans le courant de l’étude. Selon la CPUE, l’abondance des coyotes a chuté, mais pas celle des loups. Pour l’un ou l’autre des canidés, les variations en matière de rapports entre les mâles et les femelles, et entre les jeunes et les adultes n’étaient pas considérables. Nous postulons que les populations de coyotes ont été touchées de manière disproportionnée à la fois par l’environnement arctique rigoureux et par une récolte soutenue. Nos constatations joueront un rôle dans la gestion des populations de canidés sympatriques et dans la compréhension des réponses démographiques aux processus dépendant de la densité chez les loups et les coyotes, surtout dans les hautes latitudes nordiques

    Structural properties of epitaxial {\alpha}-U thin films on Ti, Zr, W and Nb

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    Thin layers of orthorhombic uranium ({\alpha}-U) have been grown onto buffered sapphire substrates by d.c. magnetron sputtering, resulting in the discovery of new epitaxial matches to Ti(00.1) and Zr(00.1) surfaces. These systems have been characterised by X-ray diffraction and reflectivity and the optimal deposition temperatures have been determined. More advanced structural characterisation of the known Nb(110) and W(110) buffered {\alpha}-U systems has also been carried out, showing that past reports of the domain structures of the U layers are incomplete. The ability of this low symmetry structure to form crystalline matches across a range of crystallographic templates highlights the complexity of U metal epitaxy and points naturally toward studies of the low temperature electronic properties of {\alpha}-U as a function of epitaxial strain

    Probabilistic Estimation of Site Specific Fault Displacements

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    The College of the Redwoods (CR) located near Eureka, California would like to upgrade a series of existing buildings that are unfortunately located on secondary faults associated with the active Little Salmon Fault (LSF) zone. In the early 1990’s a deterministic value of the maximum dip-slip displacement that had occurred on one of these secondary faults located beneath the southeast building corner of the former library was measured to be 1.7 feet. This displacement was resolved into approximately 1.5 feet horizontal offset and 0.8 feet of vertical offset, based on the secondary fault plane dip. Geologically, it has not been possible to establish the actual dates of the occurrence of the displacements on the observed faults, therefore it was assumed that they all had occurred within the last 11,000 years. The structural engineer for the project has indicated that it was not possible to design for the observed ground displacement of 1.7 feet. This limited study was undertaken to assess the variation of ground displacements that were observed over the area of ground occupied by CR’s Administration, Science, and former Library buildings. The purpose of this study was to evaluate the reasonableness of using a deterministically determined maximum value of displacement in estimating, and designing mitigations for, the structural response, or whether a probabilistic approach could be utilized. The only data available within the limited time frame allowed for the study was from a series of trench logs made as part of a project for locating building sites on the campus in the early 1990’s. As a first step the frequency distributions of both horizontal and vertical displacements located in a volume of soil comprising the area occupied by the above buildings to a depth of 14 feet were examined. The 14 feet was the maximum depth of the trenches used to provide data for the study. Probability density functions (PDF) versus displacements were developed based on the frequency distributions. The area under the PDF curves between given displacement intervals represents the probability of occurrence (POC) of that displacement. A cumulative probability of occurrence for a displacement interval can be determined by adding the individual POC’s. Based on this it was estimated that a horizontal displacement of ≤ 1.0 foot has a probability of 89% of occurring in the next 11,000 years at the site. In contrast, a vertical displacement of ≤ 1.0 foot has a probability of 88% probability of occurrence

    Reliability and Validity of the Telephone-Based eHealth Literacy Scale Among Older Adults: Cross-Sectional Survey

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    Background: Only a handful of studies have examined reliability and validity evidence of scores produced by the 8-item eHealth literacy Scale (eHEALS) among older adults. Older adults are generally more comfortable responding to survey items when asked by a real person rather than by completing self-administered paper-and-pencil or online questionnaires. However, no studies have explored the psychometrics of this scale when administered to older adults over the telephone. Objective: The objective of our study was to examine the reliability and internal structure of eHEALS data collected from older adults aged 50 years or older responding to items over the telephone. Methods: Respondents (N=283) completed eHEALS as part of a cross-sectional landline telephone survey. Exploratory structural equation modeling (E-SEM) analyses examined model fit of eHEALS scores with 1-, 2-, and 3-factor structures. Subsequent analyses based on the partial credit model explored the internal structure of eHEALS data. Results: Compared with 1- and 2-factor models, the 3-factor eHEALS structure showed the best global E-SEM model fit indices (root mean square error of approximation=.07; comparative fit index=1.0; Tucker-Lewis index=1.0). Nonetheless, the 3 factors were highly correlated (r range .36 to .65). Item analyses revealed that eHEALS items 2 through 5 were overfit to a minor degree (mean square infit/outfit values <1.0; t statistics less than –2.0), but the internal structure of Likert scale response options functioned as expected. Overfitting eHEALS items (2-5) displayed a similar degree of information for respondents at similar points on the latent continuum. Test information curves suggested that eHEALS may capture more information about older adults at the higher end of the latent continuum (ie, those with high eHealth literacy) than at the lower end of the continuum (ie, those with low eHealth literacy). Item reliability (value=.92) and item separation (value=11.31) estimates indicated that eHEALS responses were reliable and stable. Conclusions: Results support administering eHEALS over the telephone when surveying older adults regarding their use of the Internet for health information. eHEALS scores best captured 3 factors (or subscales) to measure eHealth literacy in older adults; however, statistically significant correlations between these 3 factors suggest an overarching unidimensional structure with 3 underlying dimensions. As older adults continue to use the Internet more frequently to find and evaluate health information, it will be important to consider modifying the original eHEALS to adequately measure societal shifts in online health information seeking among aging populations.Open Access Fundin

    Surveillance of RNase P, PMMoV, and CrAssphage in wastewater as indicators of human fecal concentration across urban sewer neighborhoods, Louisville, Kentucky

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    Wastewater surveillance has been widely used as a supplemental method to track the community infection levels of severe acute respiratory syndrome coronavirus 2. A gap exists in standardized reporting for fecal indicator concentrations, which can be used to calibrate the primary outcome concentrations from wastewater monitoring for use in epidemiological models. To address this, measurements of fecal indicator concentration among wastewater samples collected from sewers and treatment centers in four counties of Kentucky (N = 650) were examined. Results from the untransformed wastewater data over 4 months of sampling indicated that the fecal indicator concentration of human ribonuclease P (RNase P) ranged from 5.1 Ă— 101 to 1.15 Ă— 106 copies/ml, pepper mild mottle virus (PMMoV) ranged from 7.23 Ă— 103 to 3.53 Ă— 107 copies/ml, and cross-assembly phage (CrAssphage) ranged from 9.69Ă—103 to 1.85Ă—108 copies/ml. The results showed both regional and temporal variability. If fecal indicators are used as normalization factors, knowing the daily sewer system flow of the sample location may matter more than rainfall. RNase P, while it may be suitable as an internal amplification and sample adequacy control, has less utility than PMMoV and CrAssphage as a fecal indicator in wastewater samples when working at different sizes of catchment area. The choice of fecal indicator will impact the results of surveillance studies using this indicator to represent fecal load. Our results contribute broadly to an applicable standard normalization factor and assist in interpreting wastewater data in epidemiological modeling and monitoring
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