Alternative realities : from augmented reality to mobile mixed reality

This thesis provides an overview of (mobile) augmented and mixed reality by clarifying the different concepts of reality, briefly covering the technology behind mobile augmented and mixed reality systems, conducting a concise survey of existing and emerging mobile augmented and mixed reality applications and devices. Based on the previous analysis and the survey, this work will next attempt to assess what mobile augmented and mixed reality could make possible, and what related applications and environments could offer to users, if tapped into their full potential. Additionally, this work briefly discusses what might be the cause for mobile augmented reality not yet being widely adopted to everyday use, even though many such applications already exist for the smartphone platform, and smartglass systems slowly becoming increasingly common. Other related topics and issues that are briefly covered include information security and privacy issues related to mobile augmented and mixed reality systems, the link between mobile mixed reality and ubiquitous computing, previously conducted user studies, as well as user needs and user experience issues. The overall purpose of this thesis is to demonstrate what is already possible to implement on the mobile platform (including both hand-held devices and head-mounted configurations) by using augmented and mixed reality interfaces, and to consider how mobile mixed reality systems could be improved, based on existing products, studies and lessons learned from the survey conducted in this thesis

Spherical models of star clusters with potential escapers

An increasing number of observations of the outer regions of globular clusters (GCs) have shown a flattening of the velocity dispersion profile and an extended surface density profile. Formation scenarios of GCs can lead to different explanations of these peculiarities, therefore the dynamics of stars in the outskirts of GCs are an important tool in tracing back the evolutionary history and formation of star clusters. One possible explanation for these features is that GCs are embedded in dark matter haloes. Alternatively, these features are the result of a population of energetically unbound stars that can be spatially trapped within the cluster, known as potential escapers (PEs). We present a prescription for the contribution of these energetically unbound members to a family of self-consistent, distribution function-based models, which, for brevity, we call the Spherical Potential Escapers Stitched (SPES) models. We show that, when fitting to mock data of bound and unbound stars from an N-body model of a tidally limited star cluster, the SPES models correctly reproduce the density and velocity dispersion profiles up to the Jacobi radius, and they are able to recover the value of the Jacobi radius itself to within 20 per cent. We also provide a comparison to the number density and velocity dispersion profiles of the Galactic cluster 47 Tucanae. Such a case offers a proof of concept that an appropriate modelling of PEs is essential to accurately interpret current and forthcoming Gaia data in the outskirts of GCs, and, in turn, to formulate meaningful present-day constraints for GC formation scenarios in the early Universe

Diagnostic criteria for initial orthostatic hypotension:a narrative review

Abnormalities in orthostatic blood pressure changes upon active standing are associated with morbidity, mortality, and reduced quality of life. However, over the last decade, several population-based cohort studies have reported a remarkably high prevalence (between 25 and 70%) of initial orthostatic hypotension (IOH) among elderly individuals. This has raised the question as to whether the orthostatic blood pressure patterns in these community-dwelling elderly should truly be considered as pathological. If not, redefining of the systolic cutoff values for IOH (i.e., a value ≥ 40 mmHg in systolic blood pressure in the first 15 s after standing up) might be necessary to differ between normal aging and true pathology. Therefore, in this narrative review, we provide a critical analysis of the current reference values for the changes in systolic BP in the first 60 s after standing up and discuss how these values should be applied to large population studies. We will address factors that influence the magnitude of the systolic blood pressure changes following active standing and the importance of standardization of the stand-up test, which is a prerequisite for quantitative, between-subject comparisons of the postural hemodynamic response

Citizen Journalism at the Margins

Amidst burgeoning literature on citizen journalism, we still know relatively little about how and why genuinely marginalised groups seek to use this form of reporting to challenge their exclusion. In this article, we aim to address this gap by analysing two UK citizen journalism initiatives emanating from The Big Issue Foundation, a national homeless organisation, and Access Dorset, a regional charity for disabled and elderly people. These case studies are united by the authors’ involvement in both instances, primarily through designing and delivering bespoke citizen journalism education and mentoring. Based on over 40 hours of interviews with participants of the workshops and 36 hours of participant observation, we analyse the challenges participants faced in their journey to become citizen journalists. This included: low self-esteem, physical health and mental wellbeing, the need for accessible and adaptable technology, and overcoming fear associated with assuming a public voice. We also analyse marginalised groups’ attitudes to professional journalism and education, and its role in shaping journalistic identity and self-empowerment. Whilst demonstrably empowering and esteem building,our participants were acutely aware of societal power relations that were seemingly still beyond their ability to influence. Those who are marginalised are, nevertheless, in the best position to use citizen journalism as a conduit for social change, we argue - though challenges remain even at the grassroots level to foster and sustain participatory practices

The inner lives of early modern travel

This article assesses the role of memory, interiority, and intergenerational relations in the framing of early modern experiences and narratives of travel. It adopts as its focus three generations of the Clerk family of Penicuik, Scotland, whose travels through Europe from the mid-seventeenth century onward proved formative in the creation of varied ‘cosmopolitan’ stances within the family. While such widely studied practices as the ‘Grand Tour’ have drawn on discourses of encounter and cultural engagement within the broader narratives of the ‘long’ eighteenth century, this article reveals a family made deeply anxious by the consequences of travel, both during and after the act. Using diaries, manuscript correspondence, memoirs, and material objects, this article reveals the many ways in which travel was fashioned before, during, and long after it was undertaken. By shifting focus away from the act of travel itself and towards its subsequent afterlives, it explores the ways in which these individuals internalized what they experienced in the course of travel, how they reconciled it with the familiar, quotidian world to which they returned, and how the ‘cosmopolitan’ worldviews they brought home were made to inform the generations that followed

Probing dark matter with star clusters: a dark matter core in the ultra-faint dwarf Eridanus II

We present a new technique to probe the central dark matter (DM) density profile of galaxies that harnesses both the survival and observed properties of star clusters. As a first application, we apply our method to the `ultra-faint' dwarf Eridanus II (Eri II) that has a lone star cluster ~45 pc from its centre. Using a grid of collisional $N$-body simulations, incorporating the effects of stellar evolution, external tides and dynamical friction, we show that a DM core for Eri II naturally reproduces the size and the projected position of its star cluster. By contrast, a dense cusped galaxy requires the cluster to lie implausibly far from the centre of Eri II (>1 kpc), with a high inclination orbit that must be observed at a particular orbital phase. Our results, therefore, favour a dark matter core. This implies that either a cold DM cusp was `heated up' at the centre of Eri II by bursty star formation, or we are seeing an evidence for physics beyond cold DM.Comment: Minor changes to match the version in press in MNRA

Consensus statement on abusive head trauma in infants and young children

Abusive head trauma (AHT) is the leading cause of fatal head injuries in children younger than 2 years. A multidisciplinary team bases this diagnosis on history, physical examination, imaging and laboratory findings. Because the etiology of the injury is multifactorial (shaking, shaking and impact, impact, etc.) the current best and inclusive term is AHT. There is no controversy concerning the medical validity of the existence of AHT, with multiple components including subdural hematoma, intracranial and spinal changes, complex retinal hemorrhages, and rib and other fractures that are inconsistent with the provided mechanism of trauma. The workup must exclude medical diseases that can mimic AHT. However, the courtroom has become a forum for speculative theories that cannot be reconciled with generally accepted medical literature. There is no reliable medical evidence that the following processes are causative in the constellation of injuries of AHT: cerebral sinovenous thrombosis, hypoxic-ischemic injury, lumbar puncture or dysphagic choking/vomiting. There is no substantiation, at a time remote from birth, that an asymptomatic birth-related subdural hemorrhage can result in rebleeding and sudden collapse. Further, a diagnosis of AHT is a medical conclusion, not a legal determination of the intent of the perpetrator or a diagnosis of murder. We hope that this consensus document reduces confusion by recommending to judges and jurors the tools necessary to distinguish genuine evidence-based opinions of the relevant medical community from legal arguments or etiological speculations that are unwarranted by the clinical findings, medical evidence and evidence-based literature

Alternative realities : from augmented reality to mobile mixed reality

This thesis provides an overview of (mobile) augmented and mixed reality by clarifying the different concepts of reality, briefly covering the technology behind mobile augmented and mixed reality systems, conducting a concise survey of existing and emerging mobile augmented and mixed reality applications and devices. Based on the previous analysis and the survey, this work will next attempt to assess what mobile augmented and mixed reality could make possible, and what related applications and environments could offer to users, if tapped into their full potential. Additionally, this work briefly discusses what might be the cause for mobile augmented reality not yet being widely adopted to everyday use, even though many such applications already exist for the smartphone platform, and smartglass systems slowly becoming increasingly common. Other related topics and issues that are briefly covered include information security and privacy issues related to mobile augmented and mixed reality systems, the link between mobile mixed reality and ubiquitous computing, previously conducted user studies, as well as user needs and user experience issues. The overall purpose of this thesis is to demonstrate what is already possible to implement on the mobile platform (including both hand-held devices and head-mounted configurations) by using augmented and mixed reality interfaces, and to consider how mobile mixed reality systems could be improved, based on existing products, studies and lessons learned from the survey conducted in this thesis