A systematic study of Lyman-Alpha transfer through outflowing shells: Model parameter estimation

Outflows promote the escape of Lyman-$\alpha$ (Ly$\alpha$) photons from dusty interstellar media. The process of radiative transfer through interstellar outflows is often modelled by a spherically symmetric, geometrically thin shell of gas that scatters photons emitted by a central Ly$\alpha$ source. Despite its simplified geometry, this `shell model' has been surprisingly successful at reproducing observed Ly$\alpha$ line shapes. In this paper we perform automated line fitting on a set of noisy simulated shell model spectra, in order to determine whether degeneracies exist between the different shell model parameters. While there are some significant degeneracies, we find that most parameters are accurately recovered, especially the HI column density ($N_{\rm HI}$) and outflow velocity ($v_{\rm exp}$). This work represents an important first step in determining how the shell model parameters relate to the actual physical properties of Ly$\alpha$ sources. To aid further exploration of the parameter space, we have made our simulated model spectra available through an interactive online tool.Comment: 10 pages, 6 figures. Matches version published in ApJ. Our grid of Lyman alpha spectra can be accessed at http://bit.ly/man-alpha through an interactive online too

Playing catch-up: investigating public and institutional policies for OER practices in Australia

This article explores many of the most well-known Open Educational Resource (OER) initiatives worldwide and then reports on OER developments in Australia. It also discusses a current research project funded by the Australian Learning and Teaching Council (ALTC), including its design and methods of data collection and analysis. Although the study reported here is ongoing, a survey of the tertiary sector to establish current 'state of play' of OERs in Australia has been completed. The authors examine a preliminary analysis that focuses mostly on OER policies at governmental and institutional levels. The analysis shows that the OER movement remains relatively immature in Australia. Also, according to the survey's participants, the government and educational institutions need to give much greater consideration to a regulatory framework in which the use of OER and Open Educational Practices (OEP) can be fostered and encouraged. Isolated OER activities exist, but there appears to be a great deal of catching up required if Australia is to have coordinated initiatives to foster innovation and a culture of more OEPs

The Effects of Energy Beverages in Counteracting the Symptoms of Mild Hypoxia at Legal General Aviation Altitudes

The purpose of this thesis was to conduct preliminary research, in the form of a pilot study, concerning the natural effects of hypoxia compared to the effects of hypoxia experienced after the consumption of an energy beverage. The study evaluated the effects of hypoxia on FAA certificated pilots at a simulated legal general aviation altitude, utilizing the normobaric High Altitude Lab (HAL) located at Embry Riddle Aeronautical University, Daytona Beach, Florida. The researcher tested 11 subjects, who completed three simulated flight tasks within the HAL using the Frasca International Mentor Advanced Aviation Training Device (AATD). The flight tasks were completed after consuming Red Bull® , Monster® , or a placebo beverage. The researcher derived three test variables from core outputs of the AATD: lateral deviations from the glide slope, vertical deviations from the localizer, and airspeed deviations from the target speed of 100 knots. A repeated-measures ANOVA was carried out to determine effects of the beverages on the test variables. While results were non-significant, the researcher concluded that further research should be conducted with a larger sample

A Review and Case Study of Strategic Carbon Management in the UK Higher Education Sector.

Climate change is arguably one of the greatest environmental challenges facing the world today, bringing organisations under increasing pressure from government, shareholders and stakeholders to reduce carbon emissions. The Higher Education (HE) sector has a significant social and economic impact and is not exempt from challenging carbon reduction targets, in fact, it is argued, should be demonstrating leadership in the field. The term ‘carbon management’ is popular in the literature but strategic carbon management (SCM) is an under-developed and under-researched area as it is an applied concept, especially within the HE sector. Scope 1 and 2 emissions reduction initiatives have received more attention than scope 3 thereby missing a significant opportunity for fully effective carbon reduction. These gaps have been identified through analysis of the academic and practitioner literature, reports, and websites. The study proposed in this paper will look into the gaps and possible future research direction of SCM in the HE sector through a case study of De Montfort University (DMU). It will explore how carbon emissions can be reduced strategically and develop a systematic and comprehensive strategic management approach to doing so. Finally this paper makes some provisional principles for transferable best practices for the HE sector

Vessel calibre and haemoglobin effects on pulse oximetry

Despite its success as a clinical monitoring tool, pulse oximetry may be improved with respect to the need for empirical calibration and the reports of biases in readings associated with peripheral vasoconstriction and haemoglobin concentration. To effect this improvement, this work aims to improve the understanding of the photoplethysmography signal - as used by pulse oximeters, and investigates the effect of vessel calibre and haemoglobin concentration on pulse oximetry. The digital temperature and the transmission of a wide spectrum of light through the fingers of 57 people with known haemoglobin concentrations were measured, and simulations of the transmission of that spectrum of light through finger models were performed. Ratios of pulsatile attenuations of light as used in pulse oximetry were dependent upon peripheral temperature and on blood haemoglobin concentration. In addition, both the simulation and in vivo results showed that the pulsatile attenuation of light through fingers was approximately proportional to the absorption coefficients of blood, only when the absorption coefficients were small. These findings were explained in terms of discrete blood vessels acting as barriers to light transmission through tissue. Due to the influence of discrete blood vessels on light transmission, pulse oximeter outputs tend to be dependent upon haemoglobin concentration and on the calibre of pulsing blood vessels - which are affected by vasoconstriction/vasodilation. The effects of discrete blood vessels may account for part of the difference between the Beer–Lambert pulse oximetry model and empirical calibration

The inheritance of resistance to bacterial leaf spot of lettuce caused by Xanthomonas campestris pv. vitians in three lettuce cultivars.

Lettuce yields can be reduced by the disease bacterial leaf spot (BLS) caused by the pathogen Xanthomonas campestris pv. vitians (Xcv) and host resistance is the most feasible method to reduce disease losses. The cultivars La Brillante, Pavane and Little Gem express an incompatible host-pathogen interaction as a hypersensitive response (HR) to California strains of Xcv resulting in resistance. Little was known about the inheritance of resistance; however, resistance to other lettuce pathogens is often determined by resistance gene candidates (RGCs) encoding nucleotide-binding leucine-rich repeat (NB-LRR) proteins. Therefore, we determined the inheritance of BLS resistance in the cultivars La Brillante, Little Gem and Pavane and mapped it relative to RGCs. The reaction to Xcv was analyzed in nine F1, F2 and recombinant inbred line populations of lettuce from HR×compatible or HR×HR crosses. The HR in La Brillante, Pavane and Little Gem is conditioned by single dominant genes, which are either allelic or closely linked genes. The resistance gene in La Brillante was designated Xanthomonas resistance 1 (Xar1) and mapped to lettuce linkage group 2. Xar1 is present in a genomic region that contains numerous NB-LRR encoding RGCs and functional pathogen resistance loci in the RGC2 family. The Xar1 gene confers a high level of BLS resistance in the greenhouse and field that can be introgressed into commercial lettuce cultivars to reduce BLS losses using molecular markers