Comparisons of the motivational sources of high school business students

The purpose of this study was to determine and compare the motivational sources of students based on gender, course nature, and grade level. The respondents include a sample of the students in the Business Department at Bearden High School (Knoxville, TN) during the last nine weeks of the spring semester of 2001. Keyboarding classes during the first nine weeks were not included in the sample. Each respondent reported on his or her motivational sources using the survey instrument developed by the researcher. Major findings of the study were (a) that the respondents had an optimal combination of extrinsic and intrinsic motivational sources, which the teacher can foster and build upon within instruction and (b) difference in motivational sources was most pronounced between freshmen and seniors. Teachers who have a combination of these grade levels in the classroom should recognize and accommodate them within business courses

Fabrication techniques developed for small- diameter, thin-wall tungsten and tungsten alloy tubing

Report describes methods for the fabrication of tungsten and tungsten alloys into small-diameter, thin-wall tubing of nuclear quality. The tungsten, or tungsten alloy tube blanks are produced by double extrusion. Plug-drawing has emerged as an excellent secondary fabrication technique for the reduction of the overall tube dimensions

Effect of muscle force during stretch on eccentric contraction-induced muscle damage

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recor

A nonlinear land use regression approach for modelling NO2 concentrations in urban areas—Using data from low-cost sensors and diffusion tubes

Land Use Regression (LUR) based on multiple linear regression model is one of the techniques used most frequently for modelling the spatial variability of air pollution and assessing exposure in urban areas. In this paper, a nonlinear generalised additive model is proposed for LUR and its performance is compared to a linear model in Sheffield, UK for the year 2019. Pollution models were estimated using NO2 measurements obtained from 188 diffusion tubes and 40 low-cost sensors. Performance of the models was assessed by calculating several statistical metrics including correlation coefficient (R) and root mean square error (RMSE). High resolution (100 m × 100 m) maps demonstrated higher levels of NO2 in the city centre, eastern side of the city and on major roads. The results showed that the nonlinear model outperformed the linear counterpart and that the model estimated using NO2 data from diffusion tubes outperformed the models using data from low-cost sensors or both low-cost sensors and diffusion tubes. The proposed method provides a basis for further application of advanced nonlinear modelling approaches to constructing LUR models in urban areas which enable quantifying small scale variability in pollution levels

Traits, habitats, and clades: Identifying traits of potential importance to environmental filtering

Environmental filtering is a fundamental process in the ecological assembly of communities. Recently developed phylogenetic tools identify patterns associated with environmental filtering across whole communities. Here we introduce a novel method that allows the detection of traits involved in the environmental filtering of species from specific clades in specific habitat types. Our approach identifies nonindependent trait/habitat/clade (THC) associations and also provides a framework for detecting clearly defined two‐way trait/clade, trait/habitat, and clade/habitat associations. The THC method relies on exact binomial tests and differentiates THC associations resulting from a three‐way interaction from those that are generated by one or more underlying significant two‐way interactions. It can also detect THC associations for which there are no significant two‐way associations (trait/habitat, trait/clade, clade/habitat). To illustrate the THC method, we examine plant pollination and dispersal traits from six habitat types in a fragmented Costa Rican landscape. Results suggest that these traits are not widely important for the environmental filtering of most clades in this landscape, but animal dispersal and insect pollination are involved in the filtering of monocots and the Piperaceae in rain forest understory

Performance of AAOmega: the AAT multi-purpose fibre-fed spectrograph

AAOmega is the new spectrograph for the 2dF fibre-positioning system on the Anglo-Australian Telescope. It is a bench-mounted, double-beamed design, using volume phase holographic (VPH) gratings and articulating cameras. It is fed by 392 fibres from either of the two 2dF field plates, or by the 512 fibre SPIRAL integral field unit (IFU) at Cassegrain focus. Wavelength coverage is 370 to 950nm and spectral resolution 1,000-8,000 in multi-Object mode, or 1,500-10,000 in IFU mode. Multi-object mode was commissioned in January 2006 and the IFU system will be commissioned in June 2006. The spectrograph is located off the telescope in a thermally isolated room and the 2dF fibres have been replaced by new 38m broadband fibres. Despite the increased fibre length, we have achieved a large increase in throughput by use of VPH gratings, more efficient coatings and new detectors - amounting to a factor of at least 2 in the red. The number of spectral resolution elements and the maximum resolution are both more than doubled, and the stability is an order of magnitude better. The spectrograph comprises: an f/3.15 Schmidt collimator, incorporating a dichroic beam-splitter; interchangeable VPH gratings; and articulating red and blue f/1.3 Schmidt cameras. Pupil size is 190mm, determined by the competing demands of cost, obstruction losses, and maximum resolution. A full suite of VPH gratings has been provided to cover resolutions 1,000 to 7,500, and up to 10,000 at particular wavelengths.Comment: 13 pages, 4 figures; presented at SPIE, Astronomical Telescopes and Instrumentation, 24 - 31 May 2006, Orlando, Florida US

Analysis of air pollution in urban areas with Airviro dispersion model—A case study in the city of Sheffield, United Kingdom

Two air pollutants, oxides of nitrogen (NOx) and particulate matter (PM10), are monitored and modelled employing Airviro air quality dispersion modelling system in Sheffield, United Kingdom. The aim is to determine the most significant emission sources and their spatial variability. NOx emissions (ton/year) from road traffic, point and area sources for the year 2017 were 5370, 6774, and 2425, whereas those of PM10 (ton/year) were 345, 1449, and 281, respectively, which are part of the emission database. The results showed three hotspots of NOx, namely the Sheffield City Centre, Darnall and Tinsley Roundabout (M1 J34S). High PM10 concentrations were shown mainly between Sheffield Forgemasters International (a heavy engineering steel company) and Meadowhall Shopping Centre. Several emission scenarios were tested, which showed that NOx concentrations were mainly controlled by road traffic, whereas PM10 concentrations were controlled by point sources. Spatiotemporal variability and public exposure to air pollution were analysed. NOx concentration was greater than 52 µg/m3 in about 8 km2 area, where more than 66 thousand people lived. Models validated by observations can be used to fill in spatiotemporal gaps in measured data. The approach used presents spatiotemporal situation awareness maps that could be used for decision making and improving the urban infrastructure

Species and functional diversity of native and human-dominated plant communities

Despite growing attention to how human activities alter plant communities, little is known about the ecosystem consequences of these changes. We explore the relationship between species and functional diversity of herbaceous and shrubby plant communities in forested and deforested habitats in three Neotropical landscapes. We focus on six traits: pollination mechanism, dispersal mechanism, growth form, fruit type, fruit size, and seed size. We ask: (1) What is the relationship between species richness and functional diversity (trait state richness)? (2) Do species/functional diversity relationships differ between forested and deforested habitats? and (3) Are observed species/functional diversity patterns more consistent with ecological filtering or differentiation-based assembly processes? We show that species richness is often a weak surrogate for functional diversity, depending on the trait. Species/functional diversity relationships differ significantly between forested and deforested habitats, but the nature of-differences is trait dependent. Dispersal mechanism and fruit type number increased more rapidly in deforested than forested habitats, but the opposite was true for most other traits. Using a null model, we found evidence of ecological filtering for most traits in both habitats. Results demonstrate that deforested habitats do not necessarily contain lower functional diversity than forest but that the ecological assembly processes influencing community function in deforested communities differ dramatically from forest

A bridge between the RNA and protein worlds? Accelerating delivery of chemical reactivity to RNA and DNA by a specific short peptide (AAKK)4

AbstractBackground: RNA can catalyze diverse chemical reactions, leading to the hypothesis that an RNA world existed early in evolution. Today, however, catalysis by naturally occurring RNAs is rare and most chemical transformations within cells require proteins. This has led to interest in the design of small peptides capable of catalyzing chemical transformations.Results: We demonstrate that a short lysine-rich peptide (AAKK)4 can deliver a nucleophile to DNA or RNA and amplify the rate of chemical modification by up to 3400-fold. We also tested similar peptides that contain ornithine or arginine in place of lysine, peptides with altered stereochemistry or orientation, and peptides containing eight lysines but with different spacing. Surprisingly, these similar peptides function much less well, suggesting that specific combinations of amino acids, charge distribution, and stereochemistry are necessary for the rate enhancement by (AAKK)4.Conclusions: By appending other reactive groups to (AAKK)4 it should be possible to greatly expand the potential for small peptides to directly catalyze modification of DNA or RNA or to act as cofactors to promote ribozyme catalysis