Any Time? Any Place? The impact on student learning of an on-line learning environment.

Original paper can be found at: http://www.actapress.com/Content_of_Proceeding.aspx?proceedingID=292#pages Copyright ACTA Press [Full text of this paper is not available in the UHRA]An increasing number of HE institutions are adopting virtual and managed learning environments (VLEs and MLEs), which offer flexible access to on-line learning materials all day and every day. There are multiple claims about e-learning enhancing learning and teaching (eg. [1] Britain and Liber, 1999; [2]Conole, 2002; [4]Allen, 2003; [5]Littlejohn and Higginson, 2003) such as supporting active learning, facilitative rather than didactic teaching and increased student motivation but these are not pre determined outcomes. Much depends on how lecturers use the available technology and how students respond to that use. This paper reports on a research project which has evaluated the students' own experience of on-line learning at the University of Hertfordshire. Using its own institution-wide MLE (StudyNet) academic staff at the university have been able to offer students on-line access to their study material from September 2001. Activities available for students using StudyNet include participating in discussion forums, using formative assessment materials and accessing journal articles as well as viewing and downloading courseware for each of their courses. Students were invited to participate in a questionnaire and focus groups to identify the characteristics of the on-line learning environment which benefited their learning

Orbital payload delivery using hydrogen and hydrocarbon fuelled scramjet engines

This paper compares the performance of two different launch systems; one with a hydrogen fuelled scramjet stage and one with a hydrocarbon fuelled scramjet stage. The two launch systems are optimized with respect to payload delivery capability and then compared, assuming a fixed launch mass. A rocket powered booster is used to achieve the required scramjet ignition conditions and a rocket powered orbital stage is used to accelerate the payload from scramjet shut-down to low earth orbit. The trajectory simulator includes a full spheroidal, rotating earth model, a fourth order gravitation model and an MSISE93 atmosphere model. A gradient projection optimization routine is used to achieve an optimal solution using a set of time referenced vertical accelerations as optimization parameters. Hypersonic engine performance is determined using a quasi-one-dimensional scramjet model. Results show that a hydrogen powered scramjet launch system outperforms a hydrocarbon powered system due to its higher specific impulse and peak Mach number. While payload mass fractions are shown to be favorable, the high structural requirements of the scramjet imply that reusability is a key characteristic to make them financially viable. Trajectories were found to be dominated by their lift requirements, which outweighed any performance advantage for hydrocarbon fuels in terms of their better storage capability.M.R. Tetlow and C.J. Doola

Patient-specific stopping power calibration for proton therapy planning based on single-detector proton radiography.

A simple robust optimizer has been developed that can produce patient-specific calibration curves to convert x-ray computed tomography (CT) numbers to relative stopping powers (HU-RSPs) for proton therapy treatment planning. The difference between a digitally reconstructed radiograph water-equivalent path length (DRRWEPL) map through the x-ray CT dataset and a proton radiograph (set as the ground truth) is minimized by optimizing the HU-RSP calibration curve. The function of the optimizer is validated with synthetic datasets that contain no noise and its robustness is shown against CT noise. Application of the procedure is then demonstrated on a plastic and a real tissue phantom, with proton radiographs produced using a single detector. The mean errors using generic/optimized calibration curves between the DRRWEPL map and the proton radiograph were 1.8/0.4% for a plastic phantom and -2.1/ - 0.2% for a real tissue phantom. It was then demonstrated that these optimized calibration curves offer a better prediction of the water equivalent path length at a therapeutic depth. We believe that these promising results are suggestive that a single proton radiograph could be used to generate a patient-specific calibration curve as part of the current proton treatment planning workflow

Stratigraphy and Structure of the Sutton Area, Southern Quebec: Construction and Destruction of the Western Margin of the Late Precambrian Iapetus

Guidebook for field trips in Vermont: New England Intercollegiate Geological Conference, 79th annual meeting, October 16, 17 and 18, 1987: Trips C-

Aerodynamic sound from a sawtooth plate with different thickness

Acoustic performance of an airfoil can be improved with the serrated leading or trailing edge. A sawtooth plate is one of the serration shapes. In this study, the effect of sawtooth plate thickness on the aerodynamically generated noise in wake-sawtooth plate interaction at a Reynolds number of 150 is numerically investigated. Two types of sawtooth plate thickness hthick=0.2D and hthin=0.02D are investigated. Flow simulations are carried out using direct numerical simulation and the noise calculations are solved using Curle’s equation. It is found that the wake-plate interaction is more prominent for the thicker plate. Consequently, the generated aerodynamic force is bigger for thick plate than the thin plate. Sound generated from the thin plate is approximately 0.34 dB lower than the thick plate. For the sound that is due to the quadrupole source gives ± -70 dB.Keywords: Aerodynamic sound, Bluff body, Serrations, Acoustic analogy

A high-throughput screening RT-qPCR assay for quantifying surrogate markers of immunity from PBMCs

Immunoassays that quantitate cytokines and other surrogate markers of immunity from peripheral blood mononuclear cells (PBMCs), such as flow cytometry or Enzyme-Linked Immunosorbent Spot (ELIspot), allow highly sensitive measurements of immune effector function. However, those assays consume relatively high numbers of cells and expensive reagents, precluding comprehensive analyses and high-throughput screening (HTS). To address this issue, we developed a sensitive and specific reverse transcription-quantitative PCR (RT-qPCR)-based HTS assay, specifically designed to quantify surrogate markers of immunity from very low numbers of PBMCs. We systematically evaluated the volumes and concentrations of critical reagents within the RT-qPCR protocol, miniaturizing the assay and ultimately reducing the cost by almost 90% compared to current standard practice. We assessed the suitability of this cost-optimized RT-qPCR protocol as an HTS tool and determined the assay exceeds HTS uniformity and signal variance testing standards. Furthermore, we demonstrate this technique can effectively delineate a hierarchy of responses from as little as 50,000 PBMCs stimulated with CD4+ or CD8+ T cell peptide epitopes. Finally, we establish that this HTS-optimized protocol has single-cell analytical sensitivity and a diagnostic sensitivity equivalent to detecting 1:10,000 responding cells (i.e., 100 Spot Forming Cells/106 PBMCs by ELIspot) with over 90% accuracy. We anticipate this assay will have widespread applicability in preclinical and clinical studies, especially when samples are limited, and cost is an important consideration

Cross-protection between attenuated Plasmodium berghei and P. yoelii sporozoites

An attenuatedPlasmodium falciparum sporozoite (PfSPZ) vaccine is under development, in part, based on studies in mice withP. berghei. We usedP. berghei andP. yoelii to study vaccine-induced protection against challenge with a species of parasite different from the immunizing parasite in BALB/c mice. One-hundred percent of mice were protected against homologous challenge. Seventy-nine percent immunized with attenuatedP. berghei sporozoite (PbSPZ)(six experiments) were protected against challenge withP. yoelii sporozoite (PySPZ), and 63% immunized with attenuatedPySPZ(three experiments) were protected against challenge withPbSPZ. Antibodies in sera of immunized mice only recognized homologous sporozoites and could not have mediated protection against heterologous challenge. Immunization with attenuatedPySPZ orPbSPZ induced CD8+ T cell-dependent protection against heterologous challenge. Immunization with attenuatedPySPZ induced CD8+ T cell-dependent protection against homologous challenge. However, homologous protection induced by attenuatedPbSPZ was not dependent on CD8+ or CD4+ T cells, and depletion of both populations only reduced protection by 36%. Immunization of C57BL/10 mice withPbSPZ induced CD8+ T cell-dependent protection againstP. berghei, but no protection againstP. yoelii. The cross-protection data in BALB/c mice support testing a human vaccine based on attenuatedPfSPZ for its efficacy againstP. vivax

Epidemic syphilis exhibits diverse manifestations

Copyright to Australian Family Physician. Reproduced with permission. Permission to reproduce must be sought from the publisher, The Royal Australian College of General Practitioners.There are recent reports of a sustained increase in the incidence of syphilis around the world, including in the Australian cities of Sydney and Melbourne. In Queensland, there has been both an increase in the number of notifications and also a change in the epidemiology of the disease. While syphilis was previously predominantly seen in indigenous men and women, it now mostly occurs in nonindigenous men who have sex with other men - although per capita, indigenous Queenslanders remain overrepresented. Efforts to improve screening and treatment have shortened the time from diagnosis to treatment and appear to have been successful in reducing the rates of disease in remote indigenous populations. These efforts have included the establishment of a state wide syphilis register and active encouragement to remote practitioners to offer testing to patients aged 15–39 years as a part of the annual adult health check. Adoption of single dose azithromycin for syndromic treatment of urethritis and cervicitis and their contacts, albeit at a dose of only 1 g, may be having an impact as well.Andrew M Redmond; Craig M Dancer; Andrew R Doolan; Diane F Rowling; Marion L Wood

Reduced order modelling in searches for continuous gravitational waves - I. Barycentring time delays

The frequencies and phases of emission from extra-solar sources measured by Earth-bound observers are modulated by the motions of the observer with respect to the source, and through relativistic effects. These modulations depend critically on the source's sky-location. Precise knowledge of the modulations are required to coherently track the source's phase over long observations, for example, in pulsar timing, or searches for continuous gravitational waves. The modulations can be modelled as sky-location and time-dependent time delays that convert arrival times at the observer to the inertial frame of the source, which can often be the Solar system barycentre. We study the use of reduced order modelling for speeding up the calculation of this time delay for any sky-location. We find that the time delay model can be decomposed into just four basis vectors, and with these the delay for any sky-location can be reconstructed to sub-nanosecond accuracy. When compared to standard routines for time delay calculation in gravitational wave searches, using the reduced basis can lead to speed-ups of 30 times. We have also studied components of time delays for sources in binary systems. Assuming eccentricities <0.25, we can reconstruct the delays to within 100 s of nanoseconds, with best case speed-ups of a factor of 10, or factors of two when interpolating the basis for different orbital periods or time stamps. In long-duration phase-coherent searches for sources with sky-position uncertainties, or binary parameter uncertainties, these speed-ups could allow enhancements in their scopes without large additional computational burdens