SPARKPLUS for Self- and Peer Assessment on Group-Based Honours’ Research Projects

This paper explores an application of an online tool SPARKPLUS (Self and Peer Assessment Resource Kit) for the self and peer assessment on the group-based Honours’ research projects. The Honours’ research projects in School of Civil, Environmental Engineering at University of Adelaide are running in a small group of students (typically four students or less) working with an academic supervisor in a selected area for one year. Since the research project is self-directed study, it is very difficult to fairly assess the contribution of individual students to the group-based research project. The paper-based method of self and peer assessment for the Honour’s research projects was used in the previous years. The same mark was often distributed and no feedback was given. Both the students and academic staff were not satisfied with the paper-based method of self and peer assessment. Thus an online tool SPARK PLUS together with a set of assessment criteria was used for the self and peer assessment of the Honours’ research projects in 2010. Thirty-seven groups participated in the self and peer assessment of using SPARK PLUS in semester one 2010 and a series of results from the online self and peer assessment were obtained and analysed. Feedback sessions were held and substantial feedback was received from students. Based on the feedback, suggestions were made on improving use of the online tool for self and peer assessment on the Honours’ research project.Chengqing Wu, Emmanuel Chanda and John Willisonhttp://www.adelaide.edu.au/erg

Self-Consistent Response of a Galactic Disk to an Elliptical Perturbation Halo Potential

We calculate the self-consistent response of an axisymmetric galactic disk perturbed by an elliptical halo potential of harmonic number m = 2, and obtain the net disk ellipticity. Such a potential is commonly expected to arise due to a galactic tidal encounter and also during the galaxy formation process. The self-gravitational potential corresponding to the self-consistent, non-axisymmetric density response of the disk is obtained by inversion of Poisson equation for a thin disk. This response potential is shown to oppose the perturbation potential, because physically the disk self-gravity resists the imposed potential. This results in a reduction in the net ellipticity of the perturbation halo potential in the disk plane. The reduction factor denoting this decrease is independent of the strength of the perturbation potential, and has a typical minimum value of 0.75 - 0.9 for a wide range of galaxy parameters. The reduction is negligible at all radii for higher harmonics (m > or = 3) of the halo potential. (abridged).Comment: 26 pages (LaTex- aastex style), 3 .eps figures. To appear in the Astrophysical Journal, Vol. 542, Oct. 20, 200

High Frequency Multiplicative Component GARCH

This paper proposes a new way of modeling and forecasting intraday returns. We decompose the volatility of high frequency asset returns into components that may be easily interpreted and estimated. The conditional variance is expressed as a product of daily, diurnal and stochastic intraday volatility components. This model is applied to a comprehensive sample consisting of 10-minute returns on more than 2500 US equities. We apply a number of different specifications. Apart from building a new model, we obtain several interesting forecasting results. In particular, it turns out that forecasts obtained from the pooled cross section of companies seem to outperform the corresponding forecasts from company-by-company estimation

Impacts of Bacillus thuringiensis var. israelensis and Bacillus sphaericus insect larvicides on mosquito larval densities in Lusaka, Zambia

The study assessed the impact of bio-larvicides- Bacillus thuringiensis var. israelensis (Bti) and B. sphaericus (Bs) on anopheline mosquito larval densities in four selected areas of Lusaka urban district. Larval densities were determined using a standard WHO protocol at each study area prior to and after larviciding. Ninety percent (90%) of the collected mosquito larvae and pupae were preserved in 70% ethanol, while 10% were reared to adults for species identification. Prior to larviciding, the largest number of mosquito larvae collected was culicines. Among the anophelines, Anopheles coustani Laveran (13.5%) (n = 111) and An. squamosus Theobald (9.5%) (n = 78) were identified from all the study areas with An. rufipes Gough (1.1%) (n = 9) collected from one study area only. None of the major malaria vector species reported for Zambia were identified. No mosquito larvae were found in freshwater bodies following the larviciding exercise. Possible reasons for the absence of known major malaria vectors could be the re-introduction of effective vector control and loss of suitable breeding grounds. The study highlights the potential of larviciding using Bti and Bs for malaria vector control and its integration with indoor residual spraying and insecticide treated nets

High Frequency Multiplicative Component GARCH

This paper proposes a new way of modeling and forecasting intraday returns. We decompose the volatility of high frequency asset returns into components that may be easily interpreted and estimated. The conditional variance is expressed as a product of daily, diurnal and sto-chastic intraday volatility components. This model is applied to a comprehensive sample consisting of 10-minute returns on more than 2500 US equities. We apply a number of dif-ferent specifications. Apart from building a new model, we obtain several interesting fore-casting results. In particular, it turns out that forecasts obtained from the pooled cross section of companies seem to outperform the corresponding forecasts from company-by-company estimation

A fluorophore attached to nicotinic acetylcholine receptor beta M2 detects productive binding of agonist to the alpha delta site

To study conformational transitions at the muscle nicotinic acetylcholine (ACh) receptor (nAChR), a rhodamine fluorophore was tethered to a Cys side chain introduced at the beta-19' position in the M2 region of the nAChR expressed in Xenopus oocytes. This procedure led to only minor changes in receptor function. During agonist application, fluorescence increased by (Delta-F/F) approximate to 10%, and the emission peak shifted to lower wavelengths, indicating a more hydrophobic environment for the fluorophore. The dose-response relations for Delta-F agreed well with those for epibatidine-induced currents, but were shifted approximate to 100-fold to the left of those for ACh-induced currents. Because (i) epibatidine binds more tightly to the alpha-gamma-binding site than to the alpha-delta site and (ii) ACh binds with reverse-site selectivity, these data suggest that Delta-F monitors an event linked to binding specifically at the alpha-delta-subunit interface. In experiments with flash-applied agonists, the earliest detectable Delta-F occurs within milliseconds, i.e., during activation. At low [ACh] (less than or equal to 10 muM), a phase of Delta-F occurs with the same time constant as desensitization, presumably monitoring an increased population of agonist-bound receptors. However, recovery from Delta-F is complete before the slowest phase of recovery from desensitization (time constant approximate to 250 s), showing that one or more desensitized states have fluorescence like that of the resting channel. That conformational transitions at the alpha-delta-binding site are not tightly coupled to channel activation suggests that sequential rather than fully concerted transitions occur during receptor gating. Thus, time-resolved fluorescence changes provide a powerful probe of nAChR conformational changes

Fast Association Tests for Genes with FAST

Gene-based tests of association can increase the power of a genome-wide association study by aggregating multiple independent effects across a gene or locus into a single stronger signal. Recent gene-based tests have distinct approaches to selecting which variants to aggregate within a locus, modeling the effects of linkage disequilibrium, representing fractional allele counts from imputation, and managing permutation tests for p-values. Implementing these tests in a single, efficient framework has great practical value. Fast ASsociation Tests (Fast) addresses this need by implementing leading gene-based association tests together with conventional SNP-based univariate tests and providing a consolidated, easily interpreted report. Fast scales readily to genome-wide SNP data with millions of SNPs and tens of thousands of individuals, provides implementations that are orders of magnitude faster than original literature reports, and provides a unified framework for performing several gene based association tests concurrently and efficiently on the same data. Availability: https://bitbucket.org/baderlab/fast/downloads/FAST.tar.gz, with documentation at https://bitbucket.org/baderlab/fast/wiki/Hom

Tidally Compressed Gas in Centers of Early Type and Ultraluminous Galaxies

In this paper we propose that the compressive tidal field in the centers of flat-core early type galaxies and ultraluminous galaxies compresses molecular clouds producing dense gas obseved in the centers of these galaxies. The effect of galactic tidal fields is usually considered disruptive in the literature. However, for some galaxies, the mass profile flattens towards the center and the resulting galactic tidal field is not disruptive but instead it is compressive within the flat-core region. We have used the virial theorem to determine the minimum density of a molecular cloud to be stable and gravitationally bound within the tidally compressive region of a galaxy. We have applied the mechanism to determine the mean molecular cloud densities in the centers of a sample of flat-core, early-type galaxies and ultraluminous galaxies.Comment: 18 latex pages and uses aaspp4.sty, accepted for publication in Astrophysical Journa

Scalar dark matter vortex stabilization with black holes

Galaxies and their dark-matter halos are commonly presupposed to spin. But it is an open question how this spin manifests in halos and soliton cores made of scalar dark matter (SDM, including fuzzy/wave/ultralight-axion dark matter). One way spin could manifest in a necessarily irrotational SDM velocity field is with a vortex. But recent results have cast doubt on this scenario, finding that vortices are generally unstable except with substantial repulsive self-interaction. In this paper, we introduce an alternative route to stability: in both (non-relativistic) analytic calculations and simulations, a black hole or other central mass at least as massive as a soliton can stabilize a vortex within it. This conclusion may also apply to AU-scale halos bound to the sun and stellar-mass-scale Bose stars.Comment: Accepted by JCAP. 22 pages, 5 figures. Supplementary animations at https://doi.org/10.5281/zenodo.7675830 or https://www.youtube.com/playlist?list=PLHrf0iQS5SY7Xt2sjqskF3kmHd00Hrdf