Impactite and pseudotachylite from Roter Kamm Crater, Namibia

Pseudotachylite is known to occur in a variety of geologic settings including thrust belts (e.g., the Alps and the Himalayas) and impact craters such as Roter Kamm, Namibia. Controversy exists, however, as to whether pseudotachylite can be produced by shock brecciation as well as by tectonic frictional melting. Also open to debate is the question of whether pseudotachylites form by frictional fusion or by cataclasis. It was speculated that the pseudotachylite at Roter Kamm was formed by extensional settling and adjustment of basement blocks during 'late modification stage' of impact. The occurrence of pseudotachylite in association with rocks resembling quenched glass bombs and melt breccias in a relatively young crater of known impact origin offers a rare opportunity to compare features of these materials. Petrographic, x-ray diffraction, and electron microprobe analyses of the impactites and pseudotachylites are being employed to determine the modes of deformation and to assess the role of frictional melting and comminution of adjacent target rocks

Invisible Pixels Are Dead, Long Live Invisible Pixels!

Privacy has deteriorated in the world wide web ever since the 1990s. The tracking of browsing habits by different third-parties has been at the center of this deterioration. Web cookies and so-called web beacons have been the classical ways to implement third-party tracking. Due to the introduction of more sophisticated technical tracking solutions and other fundamental transformations, the use of classical image-based web beacons might be expected to have lost their appeal. According to a sample of over thirty thousand images collected from popular websites, this paper shows that such an assumption is a fallacy: classical 1 x 1 images are still commonly used for third-party tracking in the contemporary world wide web. While it seems that ad-blockers are unable to fully block these classical image-based tracking beacons, the paper further demonstrates that even limited information can be used to accurately classify the third-party 1 x 1 images from other images. An average classification accuracy of 0.956 is reached in the empirical experiment. With these results the paper contributes to the ongoing attempts to better understand the lack of privacy in the world wide web, and the means by which the situation might be eventually improved.Comment: Forthcoming in the 17th Workshop on Privacy in the Electronic Society (WPES 2018), Toronto, AC

Health and cancer prevention: knowledge and beliefs of children and young people

Objective: To collect information from children and young people about their knowledge of and attitudes towards cancer and their understanding of health and health related behaviours to inform future health promotion work. Design: Questionnaire survey of 15-16 year olds, and interviews with play materials with 9-10 year old children. Setting: Six inner city, suburban, and rural schools. Subjects: 226 children aged 15-16 years and 100 aged 9-10 years. Main outcome measures: Knowledge about different types of cancer; beliefs about health; sources of information; quality of research data obtainable from young children about cancer and health. Results: Both samples knew most about lung cancer, but there was also some knowledge of breast and skin cancer and leukaemia. Smoking, together with pollution and other environmental factors, were seen as the dominant causes of cancer. Environmental factors were mentioned more often by the inner city samples. Television and the media were the most important sources of information. Young people were more worried about unemployment than about ill health. More than half the young people did not describe their health as good, and most said they did not have a healthy lifestyle. Children were able to provide detailed information about their knowledge and understanding by using drawings as well as interviews. Conclusions: Children and young people possess considerable knowledge about cancer, especially about lung cancer and smoking, and show considerable awareness of predominant health education messages. Despite this knowledge, many lead less than healthy lifestyles. Health is not seen as the most important goal in life by many young people; the circumstances in which many children and young people live are not experienced as health promoting

Poor understanding? Challenges to global development education

© 2018 Cosmopolitan Civil Societies. All rights reserved. As members of a global community, we cohabit a metaphorically shrinking physical environment, and are increasingly connected one to another, and to the world, by ties of culture, economics, politics, communication and the like. Education is an essential component in addressing inequalities and injustices concerning global rights and responsibilities. The increasing multicultural nature of societies locally, enhanced access to distal information, and the work of charitable organisations worldwide are some of the factors that have contributed to the interest in, and need for, understanding global development education. The project on which this paper reports sought answers to the question: to what extent and in what ways can a semester-long subject enhance and extend teacher education students’ understandings of and responses to global inequalities and global development aid? In the course of the project, a continuum model emerged, as follows: Indifference or ignorance ➝ pity and charity ➝ partnership and development among equals. In particular, this paper reports on some of the challenges and obstacles that need to be addressed in order to enhance pre-service teachers’ understandings of global development education. The study, conducted in Australia, has implications for global development education in other developed nations

Any small change?: Teacher education, compassion, understandings and perspectives on global development education

Increased migration of people(s), goods, ideas and ideologies necessitate global understanding, empathies and responses on the part of teachers and their students. This paper investigates the effects on 100 primary pre-service teachers' understandings of and attitudes toward a semester-long course exploring, inter alia, global development. The research was undertaken in Sydney, Australia. Near-identical surveys were administered at the course's beginning and end, for comparison. Additionally, four students volunteered to participate in a focus group for further discussion. Students' understandings, including misunderstandings, are examined in the context of their future professional responsibilities and of the related literature. While attitudes to those in underdeveloped countries appeared generally empathetic, this was premised on relatively limited or inaccurate 'knowledge'. The paper questions the adequacy of compassion as a motivating factor in global development education and action, and related subject shortcomings. Moreover, it examines the contribution of compassion as an enabler or impediment to global equities and justices, and considers other approaches. The paper also explores implications for teacher education and accordingly posits some recommendations

Non-linear vortex dynamics and transient effects in ferromagnetic disks

We report a time resolved imaging and micromagnetic simulation study of the relaxation dynamics of a magnetic vortex in the non-linear regime. We use time-resolved photoemission electron microscopy and micromagnetic calculations to examine the emergence of non-linear vortex dynamics in patterned Ni80Fe20 disks in the limit of long field pulses. We show for core shifts beyond ~20-25% of the disk radius, the initial motion is characterized by distortions of the vortex, a transient cross-tie wall state, and instabilities in the core polarization that influence the core trajectories.Comment: 11 pages, 3 figures, submitted to Phys. Rev. Let

Changing course: The paradox of the career change student-teacher

© 2018 International Professional Development Association (IPDA). The article reports on career change student-teachers’ (CCSTs) views and experiences regarding their teacher education programs in Australia. Data were collected through an online survey distributed to universities for dissemination to enrolled CCSTs in teacher education programs. The responses from over 500 CCSTs were analysed using an interpretive lens of inquiry and analysis. Over 80% of the responses indicated tensions and paradoxes that exist in CCSTs’ lives as they come to terms with being students again. The article explores the impact on their student lives of the characteristics, experiences and expectations they bring to their studies, mediated by their previous careers and current circumstances. The findings discuss their perceptions of their teacher education programs and consider implications for CCSTs’ professional learning needs in the light of the paradoxes that emerge from the data