Multiple universes, cosmic coincidences, and other dark matters

Even when completely and consistently formulated, a fundamental theory of physics and cosmological boundary conditions may not give unambiguous and unique predictions for the universe we observe; indeed inflation, string/M theory, and quantum cosmology all arguably suggest that we can observe only one member of an ensemble with diverse properties. How, then, can such theories be tested? It has been variously asserted that in a future measurement we should observe the a priori most probable set of predicted properties (the ``bottom-up'' approach), or the most probable set compatible with all current observations (the ``top-down'' approach), or the most probable set consistent with the existence of observers (the ``anthropic'' approach). These inhabit a spectrum of levels of conditionalization and can lead to qualitatively different predictions. For example, in a context in which the densities of various species of dark matter vary among members of an ensemble of otherwise similar regions, from the top-down or anthropic viewpoints -- but not the bottom-up -- it would be natural for us to observe multiple types of dark matter with similar contributions to the observed dark matter density. In the anthropic approach it is also possible in principle to strengthen this argument and the limit the number of likely dark matter sub-components. In both cases the argument may be extendible to dark energy or primordial density perturbations. This implies that the anthropic approach to cosmology, introduced in part to explain "coincidences" between unrelated constituents of our universe, predicts that more, as-yet-unobserved coincidences should come to light.Comment: 18 JCAP-style pages, accepted by JCAP. Revised version adds references and some clarification

Between the Post and the Com-Post:Examining the Postdigital ‘Work’ of a Prefix

In examining the work of the prefix ‘post’, we aim to contribute to the current postdigital dialogue. Our paper does not provide a rationale for the use of ‘postdigital’ in the title of this journal: that has been thoroughly explored elsewhere. We want instead to consider the work the prefix might do. We look at ‘post’, as it appears to ‘act’ in the terms of ‘postmodernism’ and ‘posthumanism’, suggesting that modernism and humanism are in need of questioning and reworking. We also examine what gets ‘post-ed’, or sometimes ‘com-posted’. (Com- is another interesting prefix, meaning ‘with’.) We then consider how these inquiries inform our understanding of a ‘postdigital reality’ that humans now inhabit. We understand this as a space of learning, struggle, and hope, where ‘old’ and ‘new’ media are now ‘cohabiting artefacts’ that enmesh with the economy, politics and culture. In entering this postdigital age, there really is no turning back from a convergence of the traditional and the digital. However, this is not simply a debate about technological and non-technological media. The postdigital throws up new challenges and possibilities across all aspects of social life. We believe this opens up new avenues too, for considering ways that discourse (language-in-use) shapes how we experience the postdigital

Increasing response to a postal survey of sedentary patients – a randomised controlled trial [ISRCTN45665423]

BACKGROUND: A systematic review identified a range of methods, which can influence response rates. However, analysis specific to a healthcare setting, and in particular, involving people expected to be poor responders, was missing, We examined the effect of pre-warning letters on response rates to a postal survey of sedentary patients whom we expected a low rate of response. METHODS: Participants were randomised to receive a pre-warning letter or no pre-warning letter, seven days before sending the main questionnaire. The main questionnaire included a covering letter and pre-paid return envelope. After seven days, non-responders were sent a reminder letter and seven days later, another reminder letter with a further copy of the questionnaire and return envelope. RESULTS: 627 adults, with a mean age of 48 years (SD 13, range 18 to 78) of whom 69.2% (434/627) were women, were randomised. 49.0% (307/627) of patients were allocated to receive a pre-warning letter and 51.0% (320/627) no pre-warning letter, seven days in advance of posting the main questionnaire. The final response rate to the main questionnaire was 30.0% (92/307) amongst those sent a pre-warning letter and 20.9% (67/320) not sent a pre-warning letter, with an adjusted odds ratio of 1.60 (95% CI 1.1, 2.30). CONCLUSIONS: The relatively low cost method of sending a pre-warning letter had a modest impact on increasing response rates to a postal questionnaire sent to a group of patients for whom a low response rate was anticipated. Investigators should consider incorporating this simple intervention when conducting postal surveys, to reduce the potential for nonresponse bias and to increase the study power. Methods other than postal surveys may be needed however when a low response rate to postal surveys is likely

Research information in nurses' clinical decision-making: What is useful?

AIM: To examine those sources of information which nurses find useful for reducing the uncertainty associated with their clinical decisions. BACKGROUND: Nursing research has concentrated almost exclusively on the concept of research implementation. Few, if any, papers examine the use of research knowledge in the context of clinical decision-making. There is a need to establish how useful nurses perceive information sources are, for reducing the uncertainties they face when making clinical decisions. DESIGN: Cross-case analysis involving qualitative interviews, observation, documentary audit and Q methodological modelling of shared subjectivities amongst nurses. The case sites were three large acute hospitals in the north of England, United Kingdom. One hundred and eight nurses were interviewed, 61 of whom were also observed for a total of 180 hours and 122 nurses were involved in the Q modelling exercise. RESULTS: Text-based and electronic sources of research-based information yielded only small amounts of utility for practising clinicians. Despite isolating four significantly different perspectives on what sources were useful for clinical decision-making, it was human sources of information for practice that were overwhelmingly perceived as the most useful in reducing the clinical uncertainties of nurse decision-makers. CONCLUSIONS: It is not research knowledge per se that carries little weight in the clinical decisions of nurses, but rather the medium through which it is delivered. Specifically, text-based and electronic resources are not viewed as useful by nurses engaged in making decisions in real time, in real practice, but those individuals who represent a trusted and clinically credible source are. More research needs to be carried out on the qualities of people regarded as clinically important information agents (specifically, those in clinical nurse specialist and associated roles) whose messages for practice appear so useful for clinicians

Developing immunity to flight security risk: prospective benefits from considering aviation security as a socio-technical eco-system

Since 9/11, preventing similar terrorist disasters has been the predominant goal of aviation security. Yet, in this paper we seek to explore why it is that despite our increased knowledge of disaster causation - aviation security systems still remain vulnerable to future exploitation by adaptive terrorists and other threat groups. We adopt a novel approach, and present early directions of how we apply the benefits of high level appreciations of socio-technical and biological eco-systems to existing complex aviation transportation security systems. We propose that by approaching aviation security as a complex socio-technical eco-system, it offers an opportunity to think beyond conventional methodologies to improve system performance in a way that, hitherto, would not have been possible. The paper concerns itself with the ability for aviation socio-technical eco-systems to hold the capacity to proactively identify and mitigate pathogenic errors and violations. This narrow view is juxtaposed with identifying methods of reducing error creation ‘before’ they become system vulnerabilities. To address this problem, the paper concludes that a fresh approach, both conceptually and operationally, is required to understand that ‘true’ foresight of latent vulnerabilities can only be achieved by a system which is ‘intelligent’ and ‘self-aware’, in other words to identify and modify hostile pathogens before they are exploited. The development of true foresight in aviation security systems is critical to the prevention of future terrorist attacks