The descent of biquaternion algebras in characteristic two

In this paper we associate an invariant to a biquaternion algebra $B$ over a field $K$ with a subfield $F$ such that $K/F$ is a quadratic separable extension and $\operatorname{char}(F)=2$. We show that this invariant is trivial exactly when $B \cong B_0 \otimes K$ for some biquaternion algebra $B_0$ over $F$. We also study the behavior of this invariant under certain field extensions and provide several interesting examples

Comment on : 'multi-element signatures of stream sediments and sources under moderate to low flow conditions' by M.I. Stutter, S.J. Langan, D.G. Lumsdon, L.M. Clark

In a recent paper on ‘Multi-element signatures of stream sediments and sources under moderate to low flow conditions’, Stutter et al., 2009 M.I. Stutter, S.J. Langan, D.G. Lumsdon and L.M. Clark, Multi-element signatures of stream sediments and sources under moderate to low flow conditions, Appl. Geochem. 24 (2009), pp. 800–809. Article | PDF (392 K) | View Record in Scopus | Cited By in Scopus (2)Stutter et al. (2009) presented results of a simple sediment source tracing method based on major and trace elements for a small agricultural catchment in NE Scotland. The authors reported statistically significant, larger concentrations of four trace elements (Ce, Nd, Th and Y) in bank subsoils (n = 5) and stream bed sediments (n = 3) compared to topsoils from both pasture (n = 5) and arable (n = 5) land. They used these differences to aid discrimination between topsoil and subsoil (stream bank erosion) contributions to bed sediment. These elements may be more depleted in topsoil compared to subsoil because the former have been subject to more intense weathering over a longer period. If these naturally occurring trace elements could be used to understand the relative proportions of topsoil and subsoil contributions to headwater bed sediments this approach might be applied more widely to elucidate transport pathways for the transfer of agricultural contaminants such as particulate phosphorus to streams (Walling et al., 2008). This approach warrants further investigation across a range of catchments at different scales with contrasting land use and bedrock types. This can be undertaken using data from regional-scale geochemical surveys (Johnson et al., 2005) which include analyses of both stream bed sediments and subsoil samples. Previous studies have shown that much of lowland central England is at risk of topsoil transfer to watercourses via land drains (Chapman et al., 2003). A geochemical survey across part of central England covering 15 400 km2 was recently undertaken and these data are well-suited to testing whether three of the four trace elements identified by Stutter et al. (2009) might be used to discriminate between topsoil and subsoil in sediments more widely. Specifically, if the concentrations of these elements are significantly smaller in stream bed sediments than in the subsoil, this may be due to mixing with topsoils which have lower concentrations of these elements. Below the regional-scale survey, the methods the author used to compare the geochemical data in subsoil and bed sediments described, and the findings and their implications discussed

Helping and servicing regional small businesses: an evaluation of the Business Grow Program in the South West region of Western Australia

In October 1997 the Edith Cowan University was invited to evaluate the performance of the Business Grow Program. The program commenced on July 1, 1995, and its evaluation, scheduled to be completed by April 1998, has been undertaken to assess the performance of the Program since its instigation. The evaluation team has relied substantially on information provided by small business owners, local government representatives, industry associations, and the manager of the Program. The evaluation team would like to thank Kate Loughton for her assistance in facilitating the administration of this project. The evaluation was undertaken by Small and Medium Enterprise Research Centre (SMERC). The team consisted of Dr Xueli (Charles) Huang, Post-Doctoral Research Fellow at SMERC, Associate Professor Alan Brown, Director of SMERC, Barry Chapman, Graduate and Higher Degree Coordinator, and Robyn Morris, Senior Lecturer in Faculty of Business and Head of Business Program, Bunbury campus. SMERC is the principal research centre in the Faculty of Business at Edith Cowan University and harnesses the SME expertise of the staff in the Faculty

Leadership in the British civil service: an interpretation

This article is essentially a polemic. The argument is that when politicians and officials now talk of ‘leadership’ in the British civil service they do not use that word in the way in which it was previously used. In the past leading civil servants, acting in partnership with ministers and within constitutional constraints, exercised leadership in the sense of setting example, inspiring confidence and encouraging loyalty. The loosening of traditional constitutional patterns, the marginalization of senior officials in the policy process and the emergence of business methods as the preferred model for public ­administration have led to a political and administrative environment in which leadership in the British civil service is now about encouraging patterns of behaviour which fit in with these changes. Leadership skills are now about ‘delivery’; they are not about motivation. It is time for politicians, officials and scholars to be open about this

The dark side of FIRE: predicting the population of dark matter subhaloes around Milky Way-mass galaxies

A variety of observational campaigns seek to test dark-matter models by measuring dark-matter subhaloes at low masses. Despite their predicted lack of stars, these subhaloes may be detectable through gravitational lensing or via their gravitational perturbations on stellar streams. To set measurable expectations for subhalo populations within LambdaCDM, we examine 11 Milky Way (MW)-mass haloes from the FIRE-2 baryonic simulations, quantifying the counts and orbital fluxes for subhaloes with properties relevant to stellar stream interactions: masses down to 10^6 Msun, distances < 50 kpc of the galactic center, across z = 0 - 1 (lookback time 0 - 8 Gyr). We provide fits to our results and their dependence on subhalo mass, distance, and lookback time, for use in (semi)analytic models. A typical MW-mass halo contains ~16 subhaloes >10^7 Msun (~1 subhalo >10^8 Msun) within 50 kpc at z = 0. We compare our results with dark-matter-only versions of the same simulations: because they lack a central galaxy potential, they overpredict subhalo counts by 2-10x, more so at smaller distances. Subhalo counts around a given MW-mass galaxy declined over time, being ~10x higher at z = 1 than at z = 0. Subhaloes have nearly isotropic orbital velocity distributions at z = 0. Across our simulations, we also identified 4 analogs of Large Magellanic Cloud satellite passages; these analogs enhance subhalo counts by 1.4-2.7 times, significantly increasing the expected subhalo population around the MW today. Our results imply an interaction rate of ~5 per Gyr for a stream like GD-1, sufficient to make subhalo-stream interactions a promising method of measuring dark subhaloes.Comment: 13 pages, submitted to MNRA

From conceptual pluralism to practical agreement on policy: global responsibility for global health.

BACKGROUND: As the human cost of the global economic crisis becomes apparent the ongoing discussions surrounding the post-2015 global development framework continue at a frenzied pace. Given the scale and scope of increased globalization moving forward in a post-Millennium Development Goals era, to protect and realize health equity for all people, has never been more challenging or more important. The unprecedented nature of global interdependence underscores the importance of proposing policy solutions that advance realizing global responsibility for global health. DISCUSSION: This article argues for advancing global responsibility for global health through the creation of a Global Fund for Health. It suggests harnessing the power of the exceptional response to the combined epidemics of AIDS, TB and Malaria, embodied in the Global Fund to Fight AIDS, Tuberculosis and Malaria, to realize an expanded, reconceptualized Global Fund for Health. However this proposal creates both an analytical quandary embedded in conceptual pluralism and a practical dilemma for the scope and raison d'etre of a new Global Fund for Health. To address these issues we offer a logical framework for moving from conceptual pluralism in the theories supporting global responsibility for health to practical agreement on policy to realize this end. We examine how the innovations flowing from this exceptional response can be coupled with recent ideas and concepts, for example a global social protection floor, a Global Health Constitution or a Framework Convention for Global Health, that share the global responsibility logic that underpins a Global Fund for Health. CONCLUSIONS: The 2014 Lancet Commission on Global Governance for Health Report asks whether a single global health protection fund would be better for global health than the current patchwork of global and national social transfers. We concur with this suggestion and argue that there is much room for practical agreement on a Global Fund for Health that moves from the conceptual level into policies and practice that advance global health. The issues of shared responsibility and mutual accountability feature widely in the post-2015 discussions and need to be addressed in a coherent manner. Our article argues why and how a Global Fund for Health effectuates this, thus advancing global responsibility for global health

Energetic increases lead to niche packing in deep-sea wood falls

Mechanisms leading to variation in diversity over energetic gradients continue to challenge ecologists. Changes in diversity may reflect the environmental capacity to support species' coexistence through increased niche packing or niche space expansion. Current ecological theory predicts that increases in energy may lead to both scenarios but not their relative strengths. We use experimental deep-sea, wood-fall communities, where energy supply can be controlled, to test for the importance of niche expansion and packing in functional space over an energetic gradient. Invertebrate communities were identified and counted from 16 Acacia sp. logs ranging in size from 0.6 to 20.6 kg in mass (corresponding to energy availability) deployed at 3203 m in the Pacific Ocean for 5 years. We use four fundamental energetic species-level functional traits—food source, trophic category, motility and tiering—to characterize species niches. Increases in energy on wood falls lead to increases in species richness. This higher species richness resulted from a substantial increase in mean niche overlap, suggesting that increases in energy may afford reduced competition

No effect of repeated post-resistance exercise cold or hot water immersion on in-season body composition and performance responses in academy rugby players : A randomised controlled cross-over design

Purpose Following resistance exercise, uncertainty exists as to whether the regular application of cold water immersion attenuates lean muscle mass increases in athletes. The effects of repeated post-resistance exercise cold versus hot water immersion on body composition and neuromuscular jump performance responses in athletes were investigated. Methods Male, academy Super Rugby players (n = 18, 19.9 ± 1.5 y, 1.85 ± 0.06 m, 98.3 ± 10.7 kg) participated in a 12-week (4-week × 3-intervention, i.e., control [CON], cold [CWI] or hot [HWI] water immersion) resistance exercise programme, utilising a randomised cross-over pre–post-design. Body composition measures were collected using dual-energy X-ray absorptiometry prior to commencement and every fourth week thereafter. Neuromuscular squat (SJ) and counter-movement jump (CMJ) performance were measured weekly. Linear mixed-effects models were used to analyse main (treatment, time) and interaction effects. Results There were no changes in lean (p = 0.960) nor fat mass (p = 0.801) between interventions. CON (p = 0.004) and CWI (p = 0.003) increased (g = 0.08–0.19) SJ height, compared to HWI. There were no changes in CMJ height (p = 0.482) between interventions. Conclusion Repeated post-resistance exercise whole-body CWI or HWI does not attenuate (nor promote) increases in lean muscle mass in athletes. Post-resistance exercise CON or CWI results in trivial increases in SJ height, compared to HWI. During an in-season competition phase, our data support the continued use of post-resistance exercise whole-body CWI by athletes as a recovery strategy which does not attenuate body composition increases in lean muscle mass, while promoting trivial increases in neuromuscular concentric-only squat jump performance

No effect of repeated post-resistance exercise cold or hot water immersion on in-season body composition and performance responses in academy rugby players: A randomised controlled cross-over design

Purpose: Following resistance exercise, uncertainty exists as to whether the regular application of cold water immersion attenuates lean muscle mass increases in athletes. The effects of repeated post-resistance exercise cold versus hot water immersion on body composition and neuromuscular jump performance responses in athletes were investigated. Methods: Male, academy Super Rugby players (n = 18, 19.9 ± 1.5 y, 1.85 ± 0.06 m, 98.3 ± 10.7 kg) participated in a 12-week (4-week × 3-intervention, i.e., control [CON], cold [CWI] or hot [HWI] water immersion) resistance exercise programme, utilising a randomised cross-over pre–post-design. Body composition measures were collected using dual-energy X-ray absorptiometry prior to commencement and every fourth week thereafter. Neuromuscular squat (SJ) and counter-movement jump (CMJ) performance were measured weekly. Linear mixed-effects models were used to analyse main (treatment, time) and interaction effects. Results: There were no changes in lean (p = 0.960) nor fat mass (p = 0.801) between interventions. CON (p = 0.004) and CWI (p = 0.003) increased (g = 0.08–0.19) SJ height, compared to HWI. There were no changes in CMJ height (p = 0.482) between interventions. Conclusion: Repeated post-resistance exercise whole-body CWI or HWI does not attenuate (nor promote) increases in lean muscle mass in athletes. Post-resistance exercise CON or CWI results in trivial increases in SJ height, compared to HWI. During an in-season competition phase, our data support the continued use of post-resistance exercise whole-body CWI by athletes as a recovery strategy which does not attenuate body composition increases in lean muscle mass, while promoting trivial increases in neuromuscular concentric-only squat jump performance