Spatial curvature endgame: Reaching the limit of curvature determination

Current constraints on spatial curvature show that it is dynamically negligible: $|\Omega_{\rm K}| \lesssim 5 \times 10^{-3}$ (95% CL). Neglecting it as a cosmological parameter would be premature however, as more stringent constraints on $\Omega_{\rm K}$ at around the $10^{-4}$ level would offer valuable tests of eternal inflation models and probe novel large-scale structure phenomena. This precision also represents the "curvature floor", beyond which constraints cannot be meaningfully improved due to the cosmic variance of horizon-scale perturbations. In this paper, we discuss what future experiments will need to do in order to measure spatial curvature to this maximum accuracy. Our conservative forecasts show that the curvature floor is unreachable - by an order of magnitude - even with Stage IV experiments, unless strong assumptions are made about dark energy evolution and the $\Lambda$CDM parameter values. We also discuss some of the novel problems that arise when attempting to constrain a global cosmological parameter like $\Omega_{\rm K}$ with such high precision. Measuring curvature down to this level would be an important validation of systematics characterisation in high-precision cosmological analyses.Comment: 9 pages, 1 figure. Updated to match version published in Phys. Rev.

Open Networks, Distributed Identities: Cory Doctorow and the Literature of Free Culture

Drawing upon cultural theoretical work on free and open source software and on network cultures, this article considers how Cory Doctorow’s fiction provides a fictional cartography of the obsessions, anxieties, and opportunities that have come to preoccupy digital culture in the 2000s. However, in contrast with the now-familiar notion that the distributed networks are allowing a smooth entry into inclusive informational communities, this essay will claim that Doctorow’s fiction dramatises the emergence of alternative models of subjectivity and social belonging which function as a protest to the proprietary systems that govern the consumption, cultural location, and communication of information

Teach phenomenology the bomb: Starship Troopers, the technologized body, and humanitarian warfare

Paul Verhoeven's SF films are often concerned with how the future body will be reshaped as a technological device. Starship Troopers strangely departs from Verhoeven's own work, other SF films, and current directions in cultural theory by seeing the future body as one that is more organic than mechanical. Drawing upon and challenging ideas developed by Paul Virilio, this article argues that Starship Troopers' departure from the notion of the 'post-human' mechanized body needs to be understood not as a nostalgic reassertion of de-technologized subjectivity. Rather, Verhoeven's film sees the idea of the pure body as a dangerous anachronism. And, this article further argues, Starship Troopers suggests that narratives of human salvation - such as those that arose during Nato's interventions in the Balkans - often conceal an appetite for territorial conquest

On factoring quartics (mod p)

AbstractWe present a simplified proof of a theorem of Skolem. This result describes the factorization of a fourth degree polynomial (mod p), p an odd prime, in terms of its discriminant and the nature of the roots of a related resolvent cubic polynomial

Diels-alder reactions of perfluorocyclohexa-1,3-diene with compounds containing triple bonds

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Monitoring and detection of agitation in dementia: towards real-time and big-data solutions

The changing demographic profile of the population has potentially challenging social, geopolitical, and financial consequences for individuals, families, the wider society, and governments globally. The demographic change will result in a rapidly growing elderly population with healthcare implications which importantly include Alzheimer type conditions (a leading cause of dementia). Dementia requires long term care to manage the negative behavioral symptoms which are primarily exhibited in terms of agitation and aggression as the condition develops. This paper considers the nature of dementia along with the issues and challenges implicit in its management. The Behavioral and Psychological Symptoms of Dementia (BPSD) are introduced with factors (precursors) to the onset of agitation and aggression. Independent living is considered, health monitoring and implementation in context-aware decision-support systems is discussed with consideration of data analytics. Implicit in health monitoring are technical and ethical constraints, we briefly consider these constraints with the ability to generalize to a range of medical conditions. We postulate that health monitoring offers exciting potential opportunities however the challenges lie in the effective realization of independent assisted living while meeting the ethical challenges, achieving this remains an open research question remains.Peer ReviewedPostprint (author's final draft

Interannual variability of Mars South Polar cap

Telescopic data on the twentieth century regressions of Mars' south polar cap were reexamined for evidence of interannual variability. Several regressions, particularly that of 1956, are found to differ significantly from the mean. The possibility of correlations with major dust storms is explored

Horizontal transmission of Escherichia coli O157:H7 during cattle housing, survival kinetics in feces and water of Escherichia coli O157:H7 and characterisation of E. coli O157:H7 isolates from cattle faeces and a feedlot environment

End of project reportTeagasc acknowledges with gratitude the support of European Union Structural Funds (EAGGF) in financing this research projectEscherichia coli O157:H7 can cause severe illness and in some cases leading to death. Cattle are the main reservoir with transmission to humans occurring through contamination of food or the environment. Improved understanding of the survival and transmission and survival of E. coli O157:H7 on the farm is essential for developing future controls of this pathogen. This study showed that transmission of E. coli O157:H7 can occur rapidly in groups of housed cattle, with contamination of the pens and hides occurring in 24 hrs. The inoculation dose for cattle is lower than previously reported. Ingestion of bacteria from the hide through social grooming is important for pathogen transmission in housed cattle along with faecal contamination of the environment. Sampling hide will improve the estimation of prevalence of E. coli O157:H7 in pens