New Symmetries in Crystals and Handed Structures

For over a century, the structure of materials has been described by a combination of rotations, rotation-inversions and translational symmetries. By recognizing the reversal of static structural rotations between clockwise and counterclockwise directions as a distinct symmetry operation, here we show that there are many more structural symmetries than are currently recognized in right- or left-handed handed helices, spirals, and in antidistorted structures composed equally of rotations of both handedness. For example, though a helix or spiral cannot possess conventional mirror or inversion symmetries, they can possess them in combination with the rotation reversal symmetry. Similarly, we show that many antidistorted perovskites possess twice the number of symmetry elements as conventionally identified. These new symmetries predict new forms for "roto" properties that relate to static rotations, such as rotoelectricity, piezorotation, and rotomagnetism. They also enable symmetry-based search for new phenomena, such as multiferroicity involving a coupling of spins, electric polarization and static rotations. This work is relevant to structure-property relationships in all material structures with static rotations such as minerals, polymers, proteins, and engineered structures.Comment: 15 Pages, 4 figures, 3 Tables; Fig. 2b has error

Coupled structural and magnetic properties of ferric fluoride nanostructures part I: a Metropolis atomistic study

A modified Metropolis atomistic simulation is proposed to model the structure of grain boundaries (GBs) and interfaces in ionic nanostructured systems and is applied to the magnetically interesting case of iron trifluoride (FeF3). We chose long-range interatomic potentials adjusted on experimental results, and adapted a previously established Monte Carlo scheme consisting of various modifications of the simulated annealing/ Metropolis algorithm. Atomic structures of twisted and tilted GBs as a function of the relative disorientation of the grains have been achieved yielding close to experimentally measured properties. This approach takes into account the structure of the grains far from the interface in order to constrain the relative orientation of the grains, without any periodic boundary conditions. One concludes that a long-range coulombic falloff of the interatomic potentials is necessary to obtain GB structures presenting a correct local topology but with a smooth transition from crystalline to amorphous states. The structural features are finally discussed in terms of topological aspects and local magnetic structure.Comment: submitted to JMM

Digital Inequality and Second-Order Disasters: Social Media in the Typhoon Haiyan Recovery

This article investigates the intersection of digital and social inequality in the context of disaster recovery. In doing so, the article responds to the optimism present in recent claims about “humanitarian technology” which refers to the empowering uses and applications of interactive technologies by disaster-affected people. Drawing on a long-term ethnography with affected communities recovering from Typhoon Haiyan that hit the Philippines in 2013 triggering a massive humanitarian response, the article offers a grounded assessment of the role of social media in disaster recovery. In particular, the article focuses on whether any positive consequences associated with digital media use are equally spread among better off and socially marginalized participants. The analysis reveals sharp digital inequalities which map onto existing social inequalities. While some of our already better-off participants have access to a rich media landscape which they are able to navigate often reaping significant benefits, low-income participants are trapped in a delayed recovery with diminished social media opportunities. The fact that some participants are using social media to recover at a rapid pace while others are languishing behind represents a deepening of social inequalities. In this sense, digital inequality can amplify social inequalities leading to a potential “second-order disaster.” This refers to humanly perpetuated disasters that can even surpass the effects of the natural disaster

Modelling trust formation in health information contexts

This study explores trust formation in the context of health information. Trust as an interpersonal notion, when formed in a vulnerable state, is a response or belief about how the trusted will behave towards the trustor. This study focuses on the process of assessing the trustworthiness of information, in a dependency state of information need, through the identification of the many factors influencing this assessment. A set of propositions are developed to suggest the criteria by which trustworthiness is assessed as well as the factors that influence these judgements. The proposed model is tested in a large-scale survey using a trust inventory with factor analysis to explore the constructs of trust formation. Structural equation modelling is used to explore the relationship among the identified criteria and their influencing factors. The resulting framework contributes to the understanding of trust formation in digital information contexts on the criteria of usefulness and credibility and further research into the influencing factors is recommended

Health information seeking on the Internet: a double divide? Results from a representative survey in the Paris metropolitan area, France, 2005–2006

<p>Abstract</p> <p>Background</p> <p>The Internet is a major source of information for professionals and the general public, especially in the field of health. However, despite ever-increasing connection rates, a digital divide persists in the industrialised countries. The objective of this study was to assess the determinants involved in: 1) having or not having Internet access; and 2) using or not using the Internet to obtain health information.</p> <p>Methods</p> <p>A cross-sectional survey of a representative random sample was conducted in the Paris metropolitan area, France, in the fall of 2005 (n = 3023).</p> <p>Results</p> <p>Close to 70% of the adult population had Internet access, and 49% of Internet users had previously searched for medical information. Economic and social disparities observed in online health information seeking are reinforced by the economic and social disparities in Internet access, hence a double divide. While individuals who reported having a recent health problem were less likely to have Internet access (odds ratio (OR): 0.72, 95% confidence interval (CI): 0.53–0.98), it is they who, when they have Internet access, are the most likely to search for health information (OR = 1.44, 95% CI = 1.11–1.87).</p> <p>Conclusion</p> <p>In the French context of universal health insurance, access to the Internet varies according to social and socioeconomic status and health status, and its use for health information seeking varies also with health beliefs, but not to health insurance coverage or health-care utilisation. Certain economic and social inequalities seem to impact cumulatively on Internet access and on the use of the Internet for health information seeking. It is not obvious that the Internet is a special information tool for primary prevention in people who are the furthest removed from health concerns. However, the Internet appears to be a useful complement for secondary prevention, especially for better understanding health problems or enhancing therapeutic compliance.</p

Students' trust judgements in online health information seeking

As one of the most active groups of Internet users, students and other young people are active users of digital health information. Yet, research into young people’s evaluation of health information is limited, and no previous studies have focused on trust formation. In addition, prior studies on adults’ use of digital information do not reach a consensus regarding the key factors in trust formation. This study seeks to address this gap. A questionnaire-based survey was used to collect data from undergraduate students studying a variety of disciplines in one UK university. The Trust in Online Health Information Scale is proposed, and it includes the following dimensions: authority, style, content, usefulness, brand, ease of use, recommendation, credibility, and verification. In addition, inspection of responses to specific items/questions provides further insights into aspects of the information that were of specific importance in influencing trust judgements

Study of Radiologic Technologists’ Perceptions of Picture Archiving and Communication System (PACS) Competence and Educational Issues in Western Australia

Although the implementation of picture archiving and communication system (PACS) could increase productivity of radiology departments, this depends on factors such as the PACS competence of radiologic technologists (RTs). The purpose of this study was to investigate the RTs’ perceptions of PACS competence and educational issues in Western Australia (WA). A hardcopy questionnaire was distributed to WA RTs for obtaining their perceptions of PACS competence and educational issues. Descriptive (percentage of frequency, mean and standard deviation) and inferential statistics (t test and analysis of variance) were used to analyze the responses of the multiple choice and five-point scale questions from the returned questionnaires. The questionnaire response rate was 57.7 % (173 out of 300). The mean values of all PACS competence questions except questions 2e–g are in the range of 3.9–4.9, i.e., around competent to very competent. Participants indicated they received adequate PACS training (mean 3.8). Statistically significant variables influencing RTs’ perceptions of their PACS competence and educational issues including the age (p < 0.01), gender (p < 0.05), years of practice (p < 0.005–0.05), primary duty (p < 0.05), medical imaging qualification (p < 0.001), general computer skills (p < 0.001), and type of PACS education received (p < 0.001–0.05). The WA RTs indicated that they were competent in using the modality workstation, PACS and radiology information system, and received adequate training. However, future PACS education programs should be tailored to different RTs’ groups. For example, multiple training modules might be necessary to support the PACS competence development of older RTs and those with lower general computer literacy

Information Rx: Prescribing Good Consumerism and Responsible Citizenship

Recent medical informatics and sociological literature has painted the image of a new type of patient—one that is reflexive and informed, with highly specified information needs and perceptions, as well as highly developed skills and tactics for acquiring information. Patients have been re-named “reflexive consumers.” At the same time, literature about the questionable reliability of web-based information has suggested the need to create both user tools that have pre-selected information and special guidelines for individuals to use to check the individual characteristics of the information they encounter. In this article, we examine suggestions that individuals must be assisted in developing skills for “reflexive consumerism” and what these particular skills should be. Using two types of data (discursive data from websites and promotional items, and supplementary data from interviews and ethnographic observations carried out with those working to sustain these initiatives), we examine how users are directly addressed and discussed. We argue that these initiatives prescribe skills and practices that extend beyond finding and assessing information on the internet and demonstrate that they include ideals of consumerism and citizenship

Networked learning, stepping beyond the net generation and digital natives

This chapter critically examines the idea that young people have undergone a change in which exposure to digital and networked technologies has caused a step change in the character of a whole generation. The empirical and theoretical basis for this argument is reviewed and critical theoretical perspectives are assessed. Evidence from earlier research is compared and contrasted with evidence gathered from students who are said to be part of the new generation. The chapter explores the consequences of these ideas from the standpoint of networked learning. One aim of the chapter is to suggest ways in which the changes that have taken can be more adequately theorized in relation to the idea of networked learning. Arguments used to support generational change rely on a technological determinism and alternative accounts understand young people as active agents. I suggest ex-panding the notion of the agent to include persons enacting roles in collective or-ganizations. Overall the importance of the debate is that determinist arguments can close down debate and networked learning would be impoverished if this occurs