Discrimination and representation of relative numerosity in a bisection task by pigeons

We trained 4 pigeons in a numerical bisection task to discriminate between pairs of keylight flashes with a ratio of 1∶3 (2 vs. 6, 4 vs. 12, and 8 vs. 24) that were presented in a sample phase. Responses to the blue key were reinforced after a sequence of a larger number of flashes, and responses to the white key were reinforced after a sequence of a smaller number of flashes. The intervals between flashes in the sample phase were randomized to attenuate the covariation of temporal cues with flash number. Pigeons responded accurately in each of the discriminations, with typically 85%–90% correct responses. Transfer tests showed that the proportion of large responses increased with number and performance generalized to larger values outside the training ranges. Psychometric functions superposed when plotted on a relative scale, and estimates of Weber fractions were approximately constant, suggesting that variability was scalar. However, contrary to previous research in nonhumans, bisection points were located at the arithmetic, not geometric, mean. Hierarchical logistic regressions confirmed significant control over responding by number beyond that attributable to temporal cues. These results show that pigeons are able to respond accurately in a relative numerosity discrimination with successively presented visual stimuli, although the nature of the numerical representation and response rule remains unclear.     

Teachers' Perspectives on Working with Children Experiencing Loss

This paper investigates one aspect of the teacher's role which is likely to cause stress and in many cases some personal grief. A significant number of teachers at some point in their career find themselves offering support to pupils who have experienced loss. Using a small-scale questionnaire, the writers investigate teachers' personal perspectives on this work. The results showed the personal distress that teachers can experience and the high self-expectations they are likely to have of themselves. The kind of support that the teachers felt they needed is described, as is the proactive work which teachers might undertake.     

An Exploratory Examination and Critique of Academic Law Librarian Blogs: A Look into an Evolving Reference Communication Practice

This study is an exploratory qualitative investigation of academic library blogs with the purpose of examining how the technology of blogging is evolving for reference and research purposes at particular academic law libraries. This study uses anthropological archive research methods to study the blogs’ posts and triangulates the study with librarian blogger interviews. It provides a look into possible future directions for blogging in academic law libraries that may serve as a model for other academic libraries.     

Retraction policies of top scientific journals ranked by impact factor

Objective

This study gathered information about the retraction policies of the top 200 scientific journals, ranked by impact factor.

Methods

Editors of the top 200 science journals for the year 2012 were contacted by email.

Results

One hundred forty-seven journals (74%) responded to a request for information. Of these, 95 (65%) had a retraction policy. Of journals with a retraction policy, 94% had a policy that allows the editors to retract articles without authors’ consent.

Conclusions

The majority of journals in this sample had a retraction policy, and almost all of them would retract an article without the authors’ permission.     

Promoting effective e-learning practices through the constructivist pedagogy

Although rapid advances in technology has allowed for the growth of collaborative e-learning experiences unconstrained by time and space, technology has not been heavily infused in the activities of teaching and learning. This article examines the theory of constructivism as well as the design of e-learning activities using constructivist principles. The manner in which constructivist theory supports e-Learning is explored, and extrapolating from this pedagogical theory, some implications are provided to model effective practices of the characteristics and capacities of this powerful learning environment.     

Dielectrophoretic manipulation of ribosomal RNA

The manipulation of ribosomal RNA (rRNA) extracted from E. coli cells by dielectrophoresis (DEP) has been demonstrated over the range of 3 kHz-50 MHz using interdigitated microelectrodes. Quantitative measurement using total internal reflection fluorescence microscopy of the time dependent collection indicated a positive DEP response characterized by a plateau between 3 kHz and 1 MHz followed by a decrease in response at higher frequencies. Negative DEP was observed above 9 MHz. The positive DEP response below 1 MHz is described by the Clausius-Mossotti model and corresponds to an induced dipole moment of 3300 D with a polarizability of 7.8×10(-32) F m(2). The negative DEP response above 9 MHz indicates that the rRNA molecules exhibit a net moment of -250 D, to give an effective permittivity value of 78.5 ε(0), close to that of the aqueous suspending medium, and a relatively small surface conductance value of ～0.1 nS. This suggests that our rRNA samples have a fairly open structure accessible to the surrounding water molecules, with counterions strongly bound to the charged phosphate groups in the rRNA backbone. These results are the first demonstration of DEP for fast capture and release of rRNA units, opening new opportunities for rRNA-based biosensing devices.     

Enabling transformation through critical engagement and reflexivity: a case study of South African academics

ABSTRACT

Scholars writing on agency argue that normally, individuals who experience social structures as comfortable will tend to want to reproduce them while those who experience these structures as oppressive will want to change them. This is a bleak outlook because it suggests that those in positions of power and influence are less likely to seek to overhaul the very system of rewards and punishments that benefits them. However, there are exceptions to this pattern: instances where those who experience the structures as comfortable, nevertheless, work at transforming them. This article introduces an alternative perspective to current transformation discourses by seeking to understand why such exceptions exist. It argues that critical engagement is an important dimension of such transformation, and examines how it interacts with reflexivity to shape individual choices and reformulate interest. Drawing on a hermeneutic phenomenological analysis of in-depth interviews with 10 academics who have been identified as agents of change at one university in South Africa, we reveal how individuals are able to shift their understanding of what is or is not in their interest in a context where raced, gendered and classed interests are deeply embedded in the fabric of the society. In such contexts, reflexivity and critical personal engagement with one’s context can lead to a shift in interest and then consciousness as the individual comes to see and experience things from a different vantage point, opening up the possibility for a changed relationship with the social structure and its constraints and determining influence.     

Adolescent Perceptions of Help-Seeking Resources for Substance Abuse

Adolescent perceptions of help-seeking social resources (e.g., parents, friends, school counselor, clergyman) they would utilize if they were having substance abuse difficulties were investigated for samples of early and middle adolescents. 8 different perceived help-seeking categories were identified, and intergroup comparisons were made with regard to gender and ethnic/racial group and with regard to alcohol consumption, substance-related problems, and school misconduct. 2 perceived help-seeking categories had the highest levels of problem behaviors. The first category consisted of adolescents who identified friends as the only social resource they would utilize if they were having substance abuse problems. The second category, referred to as social isolates, indicated that they would not utilize any social resource if they were having substance abuse problems. There were approximately twice as many male social isolates as female social isolates, and blacks and Hispanics were highly overrepresented in the social isolate category.