Twinning in bcc metals under shock loading: a challenge to empirical potentials

Using density functional theory (DFT), we found that high pressures intrinsically favor twinning in niobium by reducing the thickness of a stable twin. Five empirical interatomic potentials for niobium were considered in molecular dynamics (MD) shock simulations. The results show that two potentials exhibit the experimentally observed twinning behavior. Comparing with DFT under high pressure, we found that these two potentials are capable of reproducing the generalized stacking fault (GSF) curve, but the others predict several artificial metastable states along the GSF curve resulting in an artificial structural transformation.     

Cyberbullying: the challenge to define

Cyberbullying is a reality of the digital age. To address this phenomenon, it becomes imperative to understand exactly what cyberbullying is. Thus, establishing a workable and theoretically sound definition is essential. This article contributes to the existing literature in relation to the definition of cyberbullying. The specific elements of repetition, power imbalance, intention, and aggression, regarded as essential criteria of traditional face-to-face bullying, are considered in the cyber context. It is posited that the core bullying elements retain their importance and applicability in relation to cyberbullying. The element of repetition is in need of redefining, given the public nature of material in the online environment. In this article, a clear distinction between direct and indirect cyberbullying is made and a model definition of cyberbullying is offered. Overall, the analysis provided lends insight into how the essential bullying elements have evolved and should apply in our parallel cyber universe.     

Pentecostalism in Brazil: A Brief History

Pentecostalism is a popular, fast-growing and politically active force in Brazilian society. It constitutes the greater part of what is now one of the largest practising Protestant communities in the world. However, there have been virtually no academic histories of the phenomenon. The current article, drawing heavily on the author's doctoral thesis, examines the six most important Pentecostal churches as dynamically evolving institutions. They are studied in terms of three waves of institutional creation, emphasizing the flexibility of Pentecostalism's relationship to Brazilian culture and the historical constraints on the development of each group.     

Faith and the literary imagination: the educational challenge

Divided into four parts, the article explores the relationship between literature and faith. The first part examines the connection between literature and the pursuit of truth and the second shows that literature can offer a challenging encounter with different beliefs. Part three examines some examples of the imagination at work in illuminating faith and the final section considers the educational challenge for teachers in enabling students to respond in an informed and sensitive way to literary encounters with faith.     

Humanistic education: The challenge to the counsellor

Counselling has long been considered to be an ancillary service in American education, its general purpose being to assure that the student is free enough from personal concerns and emotional problems to concentrate upon the objective of education, which is the development of the intellect (or cognitive abilities). Humanistic education questions this goal, and proposes that the objective of education should be the development of the student as a whole person, or the development of self-actualising persons. Counsellors, ideally, have always held this as their goal. When education adopts it also, then counselling will not be an ancillary activity, but will be central to the educative process.     

Ecumenism and Renewal in Brazil: an Appraisal

The ecumenical experience is a call to an experience of renewal, as it makes a challenge for a new form of being-a-church to all of the ecclesiastical proposals crystallized over the centuries. For this reason it demands a decisive opening to cultural, political and religious experiences. These do not always correspond to the criteria maintained by the ecclesiastical institutions, but they contain and manifest in their own way the fundamental values of the gospel.     

Affirming patterns of adolescent sexual identity: the challenge

Issues concerning sexual identity are not uncommon in therapy with adolescents, although they may manifest in a variety of ways. For young people who have experienced same-gender attractions or sexual experiences there is the question of how to absorb these experiences within the construction of a coherent sexual identity. In many cases the family context plays an important role in sexual identity formation and acceptance. Therapists too may play an important role in terms of two key aspects of sexual identity formation: self-definition and disclosure. Family therapists in particular occupy a unique position with respect to the adolescent and his or her family, opening up not only potential opportunities but also potential risks in practice. Practice issues are identified and explored in this paper.