855 research outputs found
The Effects Of An Incentive Program Intervention On Driver Performance In A Private Nonprofit Agency
The purpose of this study was to determine the effects of an incentive program on driver performance. Archival absenteeism, complaint, and at-fault accident data were collected around an incentive program. Results of the study showed partial support of the hypothesis that the incentive program would result in increased driver performance. Limitations of the study and organizational recommendations are presented
Rayleigh wave propagation assessment for transport corridors
Wheel loading from high-speed trains can generate seismic ‘Rayleigh’ waves that propagate in the near surface, causing track and ground displacements. These displacements can increase over low-density, poorly consolidated soils with low wave velocities. Rayleigh wave characteristics were mapped onto soil engineering geological classifications using lithological and density parameters in effective stress-based algorithms that model shear wave velocities with depth. The use of small-scale engineering geological maps and one-dimensional modelling identified low Rayleigh wave velocity profiles associated with alluvial and terrace deposits in river catchments and floodplains along the proposed High Speed 2 route in the UK. Examination of the velocity−depth profiles indicated that sites are especially susceptible to dynamic displacement amplification where train-induced ground motion occurs within an interval of up to half the wavelength of the Rayleigh wave frequency induced by the train load centres. Using the algorithms to attribute density and shear wave velocities to the engineering geological section, a two-dimensional ground model was created for an alluvial-terrace structure at Perivale. Wave propagation modelling using a finite-difference code indicated amplification due to interference effects from wave fronts that propagated along different pathways of up to 2 times on vertical and 2·5 times on the horizontal displacement
Human Apolipoprotein B Transgenic Mice Generated with 207- and 145-Kilobase Pair Bacterial Artificial Chromosomes. Evidence that a distant 5'-element confers appropriate transgene expression in the intestine
We reported previously that ~80-kilobase pair (kb) P1 bacteriophage clones spanning either the human or mouse apoB gene (clones p158 and p649, respectively) confer apoB expression in the liver of transgenic mice, but not in the intestine. We hypothesized that the absence of intestinal expression was due to the fact that these clones lacked a distant DNA element controlling intestinal expression. To test this possibility, transgenic mice were generated with 145- and 207-kb bacterial artificial chromosomes (BACs) that contained the human apoB gene and more extensive 5'- and 3'-flanking sequences. RNase protection, in situ hybridization, immunohistochemical, and genetic complementation studies revealed that the BAC transgenic mice manifested appropriate apoB gene expression in both the intestine and the liver, indicating that both BACs contained the distant intestinal element. To determine whether the regulatory element was located 5' or 3' to the apoB gene, transgenic mice were generated by co-microinjecting embryos with p158 and either the 5'- or 3'-sequences from the 145-kb BAC. Analysis of these mice indicated that the apoB gene's intestinal element is located 5' to the structural gene. Cumulatively, the transgenic mouse studies suggest that the intestinal element is located between -33 and -70 kb 5' to the apoB gene
Assessing the responses of aquatic macrophytes to the application of a lanthanum modified bentonite clay, at Loch Flemington, Scotland, UK
Loch Flemington is a shallow lake of international conservation and scientific importance. In recent decades, its status has declined as a result of eutrophication and the establishment of non-native invasive aquatic macrophytes. As previous research had identified the lake bed sediments as an important source of phosphorus (P), the P-capping material Phoslock® was applied to improve water quality. This article documents the responses of the aquatic macrophyte community by comparing data collected between 1988 and 2011. Summer water-column total P concentrations decreased significantly and water clarity increased following treatment. Aquatic plant colonisation depth increased and plant coverage of the lake bed extended. However, the submerged vegetation remained dominated by the non-native Elodea canadensis Michx. Aquatic macrophyte community metrics indicated no significant change in trophic status. Species richness and the number of ‘natural’ eutrophic characteristic species remained broadly similar with no records of rare species of conservation interest. Loch Flemington is still classified as being in ‘unfavourable no change’ condition based on its aquatic macrophytes despite the water quality improvements. The implications of these results are discussed in relation to the future management of Loch Flemington and in the wider context of trying to improve our understanding of lake restoration processes
Caring for the dying: How well prepared are general practitioners? A questionnaire study in Wales
Visible camera cryostat design and performance for the SuMIRe Prime Focus Spectrograph (PFS)
We describe the design and performance of the SuMIRe Prime Focus Spectrograph
(PFS) visible camera cryostats. SuMIRe PFS is a massively multi-plexed
ground-based spectrograph consisting of four identical spectrograph modules,
each receiving roughly 600 fibers from a 2394 fiber robotic positioner at the
prime focus. Each spectrograph module has three channels covering wavelength
ranges 380~nm -- 640~nm, 640~nm -- 955~nm, and 955~nm -- 1.26~um, with the
dispersed light being imaged in each channel by a f/1.07 vacuum Schmidt camera.
The cameras are very large, having a clear aperture of 300~mm at the entrance
window, and a mass of 280~kg. In this paper we describe the design of the
visible camera cryostats and discuss various aspects of cryostat performance
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