An explanation for the low-temperature H evolution peak in hydrogenated amorphous silicon films deposited 'on the edge of crystallinity'

The puzzling existence of a sharp low-temperature (T = 400°C) H evolution peak in compact hydrogenated amorphous silicon (a-Si : H) films deposited 'on the edge of crystallinity' is examined. From infrared absorption and X-ray diffraction (XRD) measurements, we show that none of the standard methods used to explain the existence of this peak in a-Si : H materials is applicable to the present films. From the Si-H wag-mode peak frequency, we postulate the existence of very small Si crystallites contained within the amorphous matrix. While the crystallite volume fraction is too small to be detected by XRD in the as-grown films, crystallization is observed for this material at anneal temperatures as low as 500°C. It is proposed that these crystallites catalyse the crystallization of the remainder of the amorphous matrix upon moderate annealing, enabling H surface desorption and H₂ out-diffusion to the sample surface along newly formed grain boundaries at low anneal temperatures.     

The Ethics of Ambition: A Pedagogy of the Spirit

This article presents an overview of a course entitled ‘The Ethics of Ambition’ which over the period of the last fifteen years the author has taught to undergraduates and seminarians, as well as in church-sponsored adult education programs. It summarizes and describes a number of pedagogical strategies that have evolved over time in response to the exigencies of these varying educational environments. More topically, the article offers a brief criticism of certain ‘neo-conservative’ assumptions regarding the pedagogical efficacy of the Christian narrative as these impinge upon the actual teaching situation.     

Stable negative social exchanges and health

Negative social exchanges with family, friends, and neighbors are known to be an important source of stress in daily life, and chronic stress is theorized to have especially potent impacts on health. Little is known about the health effects of stably high levels of negative social exchanges, however. In a national, longitudinal study of older adults (N = 666), we examined the association between stable negative social exchanges and health over a 2-year period. Trait-state-error models indicated that higher levels of stable negative social exchanges were significantly predictive of lower self-rated health, greater functional limitations, and a higher number of health conditions over 2 years after controlling for initial levels of health and sociodemographic variables. These results highlight the importance of examining continual and recurring interpersonal problems in efforts to understand the health effects of social relationships.     

Interbehavioral Perspectives: On Act Psychologies and the Psychological Nouns

In a recent paper, Lee contrasted “act psychologies” with cognitive psychology, alleging that the former are incomplete in their coverage of what most people consider really psychological. By including the contextual interactionist approach of J. R. Kantor with B. F. Skinner’s behaviorism under the “act psychology” umbrella, Lee has shown that she is unfamiliar with the fact that Kantor, during his 60-odd years of active writing, covered virtually every aspect of psychology. She is particularly concerned about the neglect of those psychological nouns that are meaningful abstractions without being aware that contextual interactionism (interbehavioral psychology) uses the very terms which she mentions as long as they are used in reference to interactions and not to faculties or other psychic entities.

     

Do Humans Really Learn AnBn Artificial Grammars From Exemplars?

An important topic in the evolution of language is the kinds of grammars that can be computed by humans and other animals. Fitch and Hauser (F&H; 2004) approached this question by assessing the ability of different species to learn 2 grammars, (AB)(n) and A(n) B(n) . A(n) B(n) was taken to indicate a phrase structure grammar, eliciting a center-embedded pattern. (AB)(n) indicates a grammar whose strings entail only local relations between the categories of constituents. F&H's data suggest that humans, but not tamarin monkeys, learn an A(n) B(n) grammar, whereas both learn a simpler (AB)(n) grammar (Fitch & Hauser, 2004). In their experiments, the A constituents were syllables pronounced by a female voice, whereas the B constituents were syllables pronounced by a male voice. This study proposes that what characterizes the A(n) B(n) exemplars is the distributional regularities of the syllables pronounced by either a male or a female rather than the underlying, more abstract patterns. This article replicates F&H's data and reports new controls using either categories similar to those in F&H or less salient ones. This article shows that distributional regularities explain the data better than grammar learning. Indeed, when familiarized with A(n) B(n) exemplars, participants failed to discriminate A(3) B(2) and A(2) B(3) from A(n) B(n) items, missing the crucial feature that the number of As must equal the number of Bs. Therefore, contrary to F&H, this study concludes that no syntactic rules implementing embedded nonadjacent dependencies were learned in these experiments. The difference between human linguistic abilities and the putative precursors in monkeys deserves further exploration.     

Student Therapists Grapple with Modern and Postmodern Ideas: One Program’s Approach to Training

Postmodern ideas have significantly challenged and expanded the marriage and family therapy field. Students in many training programs must grapple with models and training experiences influenced by both postmodern and modern orientations. The authors describe a particular programs training process and focus on the ways past students reflect on their professional development guided by the postmodernist-based perspective of Narrative Therapy and the modernist-based perspective of Bowen Family Systems Theory, two of the models emphasized by this program. The authors propose that these divergent philosophical orientations can interact together to support meaningful development in trainees experiences.     

Establishing the Measurement Equivalence of Online Selection Assessments Delivered on Mobile versus Nonmobile Devices

Recent usage data suggest job applicants are completing online selection assessments using mobile devices (e.g., smartphones) in greater numbers. To determine the appropriateness of this new technology, this study examined the measurement equivalence of selection assessments delivered on mobile and nonmobile devices (e.g., personal computers). Measurement invariance tests conducted with multigroup confirmatory factor analysis suggest mobile versions of a cognitive ability‐type assessment, two biodata assessments, a multimedia work simulation, and a text‐based situational judgment test appear to be equivalent to nonmobile versions. However, mobile device user latent means were half a standard deviation lower than their nonmobile counterparts for the situational judgment test. Implications for mobile device usage within selection and assessment are discussed.     

Investigating Iranian English Learners’ Private Speech Across Proficiency Levels and Gender Based on Vygotsky’s Sociocultural Theory

Journal of Psycholinguistic Research - This study was an attempt to investigate Iranian EFL learners’ private speech across proficiency levels and gender while doing reading comprehension...