The baseline intracluster entropy profile from gravitational structure formation

The radial entropy profile of the hot gas in clusters of galaxies tends to follow a power law in radius outside of the cluster core. Here we present a simple formula giving both the normalization and slope for the power-law entropy profiles of clusters that form in the absence of non-gravitational processes such as radiative cooling and subsequent feedback. It is based on seventy-one clusters drawn from four separate cosmological simulations, two using smoothed-particle hydrodynamics (SPH) and two using adaptive-mesh refinement (AMR), and can be used as a baseline for assessing the impact of non-gravitational processes on the intracluster medium outside of cluster cores. All the simulations produce clusters with self-similar structure in which the normalization of the entropy profile scales linearly with cluster temperature, and these profiles are in excellent agreement outside of 0.2 r_200. Because the observed entropy profiles of clusters do not scale linearly with temperature, our models confirm that non-gravitational processes are necessary to break the self-similarity seen in the simulations. However, the core entropy levels found by the two codes used here significantly differ, with the AMR code producing nearly twice as much entropy at the centre of a cluster.Comment: Accepted to MNRAS, 8 pages, 9 figure

The introduction of ICT in fieldwork to enhance student learning

Report of a CELT project on supporting students through innovation and researchThe aim of the project was to introduce a dedicated ICT package into the fieldwork experience in order to enhance student learning in the field at a range of levels and in a number of subject areas. The field kit consists of a laptop computer, digital camera with multi-card reader, global positioning system (GPS), video camera, portable scanner and printer. The kit is kept in a waterproof portable case specifically for student fieldwork use (Plate 1). A digital microscope and video camera is also separately available. The students have been able to use the equipment in the field in order to produce supporting materials to enhance their fieldwork. For example the IT package has been used in conjunction with a data-logger on mapping equipment allowing maps to be printed in the field for detailed recording of field sites. Also the use of digital and video cameras has allowed students to take responsibility for identifying and recording aspects of fieldwork for their reports

Legislating to address hate crimes against the LGBT community in the Commonwealth

This report, commissioned by the Human Dignity Trust on Behalf of the Equality & Justice Alliance, provides a detailed analysis of the purpose of Hate Crimes laws and assesses how these laws, already enacted in parts of the Commonwealth, are being used to tackle the pervasive violence faced by LGBT communities. The report identifies and assesses the different types and models of legislation that are being used and provides recommendations for other Commonwealth legislators

A Chat with the Dean

Effective college teaching is the answer to the problem of an increasing amount of knowledge in the field of veterinary medicine, stated Dean Kitchell about the mounting concern over how to secure more successful teaching techniques for the future

Scoliosis : lower limb asymmetries during the gait cycle

This research was presented in the form of a poster presentation at the National Symposium of Health Sciences organised by the University of Malta, on the 24th April 2014.Several studies indicate that the gait pattern of subjects suffering from scoliosis differs from the norm. However, there is conflicting evidence regarding the source of this discrepancy. The objective of this study is to evaluate lower limb asymmetries in selected gait variables. Study design: A case–control study on lower limb asymmetries during gait which can be related to scoliosis. 31 subjects with scoliosis (Study Group - SG) and an equal comparative control sample (Control Group – CG) of subjects underwent objective gait analysis with the Vicon® motion caption system whilst walking at a comfortable speed along the gait laboratory walkway. Analysis was performed at three levels: (1) Asymmetry in the SG against asymmetry in the CG, (2) Difference in magnitude of asymmetry between the SG and CG, and (3) Global mean values in the SG vs. CG. The Paired Student T-Test was used for intra-group analysis whilst the Independent Student T-Test was used for inter-group analysis of the selected parameters, which include temporal parameters (stride length, stride time, step length, individual step speed, speed of gait, cadence, swing-to-stance ratio), ground reaction force (peak GRF values during Loading and Propulsion phases, vertical component only) and electromyography (peak EMG values and their time of onset, as a percentage of the gait cycle) of two lower limb muscles (Gastronemius and Vastus Medialis). No intra-group variation was found to be significant. However, the speed of gait was found to be significantly slower (p = 0.03) in scoliotic subjects when compared to the norm, as a result of the shorter stride length (p = 0.002 and longer stride time (p = 0.001) in the SG. Furthermore, there was statistical significance in the time of onset of EMG peaks for the Lateral Gastrocnemius (p = 0.02) with regards to inter-group difference in magnitude of lower limb asymmetry and global mean values. Scoliosis is a tri-planar deformity which has some impact on the gait pattern. This research study concludes that scoliotic subjects have a slower speed of gait due to a shorter stride length and a longer stride time, together with variations in the timing of muscle activation.peer-reviewe

DevA, a GntR-like transcriptional regulator required for development in streptomyces coelicolor

The gram-positive filamentous bacterium Streptomyces coelicolor has a complex developmental cycle with three distinct phases: growth of the substrate mycelium, development of reproductive structures called aerial hyphae, and differentiation of these aerial filaments into long chains of exospores. During a transposon mutagenesis screen, we identified a novel gene (devA) required for proper development. The devA mutant produced only rare aerial hyphae, and those that were produced developed aberrant spore chains that were much shorter than wild-type chains and had misplaced septa. devA encodes a member of the GntR superfamily, a class of transcriptional regulators that typically respond to metabolite effector molecules. devA forms an operon with the downstream gene devB, which encodes a putative hydrolase that is also required for aerial mycelium formation on R5 medium. S1 nuclease protection analysis showed that transcription from the single devA promoter was temporally associated with vegetative growth, and enhanced green fluorescent protein transcriptional fusions showed that transcription was spatially confined to the substrate hyphae in the wild type. In contrast, devAB transcript levels were dramatically upregulated in a devA mutant and the devA promoter was also active in aerial hyphae and spores in this background, suggesting that DevA might negatively regulate its own production. This suggestion was confirmed by gel mobility shift assays that showed that DevA binds its own promoter region in vitro