Large scale structure in the Durham/UKST galaxy Redshift survey

The initial results from the Durham/UKST Galaxy Redshift Survey are presented here. Using this redshift survey the luminosity, clustering and dynamical properties of galaxies in the Universe are investigated. The 3-D distribution of galaxies in the Durham/UKST survey appears "cellular” on 50-100h(^-1) Mpc scales (where h is Hubble's constant in units of 100 kms(^-1) Mpc(^-1)) and is clearly more complex than a simple 1-D periodic pattern. The optical galaxy luminosity function of the Durham/UKST survey is estimated and can be fit by a Schechter function. Comparison with other determinations of the luminosity function shows good agreement, favouring a flat faint end slope to M(_b J) ~ -14.The redshift space 2-point correlation function clustering statistic is estimated from the Durham/UKST survey. Comparison with previous estimates from other redshift surveys again shows good agreement and the Durham/UKST survey gives a detection of large scale power above and beyond that of the standard cold dark matter cosmological model on 10-40h(^-1)Mpc scales. The projected correlation function is also estimated from the Durham/UKST survey and is compared with models for the real space 2-point correlation function. To estimate this real space correlation function directly, a new application of the Richardson-Lucy inversion technique is developed, tested and then applied to the Durham/UKST survey. The effects of redshift space distortions on the 2-point correlation function are investigated and modelled in the non-linear and linear regimes. The 1-D pairwise velocity dispersion of galaxies is measured to be 416 ± 36 kms(^-1) which, while being consistent with the canonical value of ~ 350 kms(^-1) is slightly smaller than recently measured values. However, this value is inconsistent with the ~ 1000 kms(^-1) value as measured in the standard cold dark matter cosmological model at a high level of significance. The ratio of the mean mass density of the Universe, Ω, and the linear bias factor, b (relating the galaxy and light distributions), is then calculated to be Ω(^0.6)/b = 0.45 ± 0.38. This favours either an open (Ω < 1) and unbiased (b = 1) Universe or a flat (Ω = 1) and biased (b ~ 2) Universe

Gluon polarization in the proton

We combine heavy-quark renormalization group arguments with our understanding of the nucleon's wavefunction to deduce a bound on the gluon polarization Delta g in the proton. The bound is consistent with the values extracted from spin experiments at COMPASS and RHIC.Comment: 4 page

A protocol for the aerial survey of penguin colonies using UAVs

Penguins, and many other seabirds, often nest in the open in large colonies, and so are amenable to aerial survey. UAVs offer a flexible and inexpensive method of achieving this but, to date, few published examples are available. We present a protocol for acquiring aerial images of penguin colonies using UAVs and describe simple, open-source tools for processing these into counts. Our approach is demonstrated using a case study for a penguin colony in the Falkland Islands. We discuss the advantages and limitations of UAVs for penguin surveys and make recommendations for their wider application

The mobility of experiential learning pedagogy: transferring ideas and practices from a large- to a small-campus setting

In this article, we examine the development of a new, experiential learning human geography and planning course at a smaller campus in Newfoundland, Canada. Our interest is twofold: to consider how pedagogical approaches can be transferred between a large urban campus and a small-town location; and to examine the benefits and complications of such transfers through a reflective examination of the resulting experiential learning program. The article captures the experiences of students, faculty, and university engagement staff in the deployment of the course. From these perspectives, we situate the decision to transfer an existing program across universities, the nuances of adapting such programs to the local context, and the challenge of meeting student desires for experiential learning amidst experimental pedagogical approaches. The paper concludes by suggesting that transferring pedagogical models across locations requires flexibility in terms of ensuring that new modules fit existing program constraints, and that such transfers have the potential to both challenge and positively transform experiential learning processes

A Modest Addendum to the English Sediment Core Meta-Database

Compilations of previous studies provide researchers with a source of valuable secondary data for re-analysis, an access route to identify relevant literature and an opportunity to systematically evaluate the research which is conducted and published. Recently Suggitt et al. (2015 Veg Hist Archbot 24, 743–747) presented a valuable compilation of core records for England. Here we present an extended version of this English Sediment Core Meta-database which includes data for 100 additional cores and improves the consistency of presentation. Despite these additions there are clearly large gaps remaining. Maximising the value of such meta-databases requires a community effort and we hope that this contribution will be a first step towards achieving this

Neurobehavioral Effects in HIV-Positive Individuals Receiving Highly Active Antiretroviral Therapy (HAART) in Gaborone, Botswana

Objective To explore the prevalence and features of HIV-associated neurocognitive disorders (HANDS) in Botswana, a sub-Saharan country at the center of the HIV epidemic. Design and Methods A cross sectional study of 60 HIV-positive individuals, all receiving highly active antiretroviral therapy (HAART), and 80 demographically matched HIV-seronegative control subjects. We administered a comprehensive neuropsychological test battery and structured psychiatric interview. The lowest 10th percentile of results achieved by control subjects was used to define the lower limit of normal performance on cognitive measures. Subjects who scored abnormal on three or more measures were classified as cognitively impaired. To determine the clinical significance of any cognitive impairment, we assessed medication adherence, employment, and independence in activities of daily living (ADL). Results HIV+ subjects were impaired for all cognitive-motor ability areas compared with matched, uninfected control subjects. Thirty seven percent of HIV+ patients met criteria for cognitive impairment. Conclusion These findings indicate that neurocognitive impairment is likely to be an important feature of HIV infection in resource-limited countries; underscoring the need to develop effective treatments for subjects with, or at risk of developing, cognitive impairment

Neurocognitive impairment among HIV-positive individuals in Botswana: a pilot study

<p>Abstract</p> <p>Background</p> <p>The primary objective of this study was to determine the prevalence of neurocognitive impairment among HIV-positive individuals in Botswana, using the International HIV Dementia Scale (IHDS). We also compared performance on the IHDS with performance on tests of verbal learning/memory and processing speed, and investigated the association between performance on the IHDS and such variables as depression, age, level of education and CD4 count.</p> <p>Methods</p> <p>We conducted a cross-sectional study of 120 HIV-positive individuals randomly selected from an outpatient HIV clinic in Gaborone, Botswana. Patients provided a detailed clinical history and underwent neuropsychological testing; measures of depression, daily activities and subjective cognitive complaints were recorded.</p> <p>Results</p> <p>Despite the fact that 97.5% of subjects were receiving highly active antiretroviral therapy (HAART), 38% met criteria for dementia on the IHDS, and 24% were diagnosed with major depressive disorder. There was a significant association between neurocognitive impairment as measured by the IHDS and performance on the other two cognitive measures of verbal learning/memory and processing speed. Level of education significantly affected performance on all three cognitive measures, and age affected processing speed and performance on the IHDS. Depression and current CD4 count did not affect performance on any of the cognitive measures.</p> <p>Conclusions</p> <p>The prevalence of neurocognitive impairment in HIV-positive individuals in Botswana is higher than expected, especially since almost all of the subjects in this study were prescribed HAART. This suggests the need to reconsider the timing of introduction of antiretroviral therapy in developing countries where HAART is generally not administered until the CD4 cell count has dropped to 200/mm³or below. The contribution of other factors should also be considered, such as poor central nervous system penetration of some antiretrovirals, drug resistance, potential neurotoxicity, and co-morbidities. Memory impairment and poor judgment may be underlying causes for behaviours that contribute to the spread of HIV and to poor adherence. It is important to identify these neurobehavioural complications of HIV so that effective treatments can be developed.</p