A group of educators' stance on the implementation of South Africa's further education and training curriculum

In their dealings with educators in the Southern Cape region of South Africa, the researchers observed among them a degree of negativity and pessimism about the implementation of the Further Education and Training (FET) policy and curriculum during 2006. Exploratory discussions supported the surmise that a gap existed between policy formulation and the actual implementation of the policy in secondary schools. A qualitative research project confirmed this surmise, and served as the basis for a theoretical examination of the dynamics behind the stance adopted by the participants.     

Video production as a tool for raising educator awareness about collaborative teacher–parent partnerships

Background:?This article describes research undertaken with teachers working in a South African township school, where parental involvement is a persistent problematic issue.

Purpose:?The purpose of the study was to explore the use of video production as a tool for assisting teachers to explore their perceptions about parental involvement in education and how these perceptions impact on their relationships with parents.

Sample:?Nine teachers participated voluntarily in the study, seven from two different primary schools and two from the high school in the township. All the teachers were isiXhosa speaking and had grown up in communities similar to the one in which the school was situated.

Design and methods:?Following a participatory research approach, we guided the participating teachers to design and produce short videos about issues that they perceived to impact negatively on their teaching and learning. We then facilitated critical reflection on these videos, specifically exploring how they had portrayed the teacher–parent relationship in each case.

Results:?Through a content analysis of a structured focus group and their written responses to questions, we identified emergent themes that made it apparent that the participating teachers viewed parents in a negative light, indicating a lack of the respect that would be required for the formation and sustainment of co-operative relationships. These themes were then used to facilitate discussion to raise teacher awareness of how the teachers' perceptions of parents could hinder meaningful parental involvement.

Conclusion:?The article offers an example of how visual methodologies can be useful tools for beginning to raise teacher awareness around issues, as a precursor to helping teachers to take action to improve a given situation.     

Single cell rheometry with a microfluidic constriction: Quantitative control of friction and fluid leaks between cell and channel walls

We report how cell rheology measurements can be performed by monitoring the deformation of a cell in a microfluidic constriction, provided that friction and fluid leaks effects between the cell and the walls of the microchannels are correctly taken into account. Indeed, the mismatch between the rounded shapes of cells and the angular cross-section of standard microfluidic channels hampers efficient obstruction of the channel by an incoming cell. Moreover, friction forces between a cell and channels walls have never been characterized. Both effects impede a quantitative determination of forces experienced by cells in a constriction. Our study is based on a new microfluidic device composed of two successive constrictions, combined with optical interference microscopy measurements to characterize the contact zone between the cell and the walls of the channel. A cell squeezed in a first constriction obstructs most of the channel cross-section, which strongly limits leaks around cells. The rheological properties of the cell are subsequently probed during its entry in a second narrower constriction. The pressure force is determined from the pressure drop across the device, the cell velocity, and the width of the gutters formed between the cell and the corners of the channel. The additional friction force, which has never been analyzed for moving and constrained cells before, is found to involve both hydrodynamic lubrication and surface forces. This friction results in the existence of a threshold for moving the cells and leads to a non-linear behavior at low velocity. The friction force can nevertheless be assessed in the linear regime. Finally, an apparent viscosity of single cells can be estimated from a numerical prediction of the viscous dissipation induced by a small step in the channel. A preliminary application of our method yields an apparent loss modulus on the order of 100 Pa s for leukocytes THP-1 cells, in agreement with the literature data.     

Gradient descent optimization of smoothed information retrieval metrics

Most ranking algorithms are based on the optimization of some loss functions, such as the pairwise loss. However, these loss functions are often different from the criteria that are adopted to measure the quality of the web page ranking results. To overcome this problem, we propose an algorithm which aims at directly optimizing popular measures such as the Normalized Discounted Cumulative Gain and the Average Precision. The basic idea is to minimize a smooth approximation of these measures with gradient descent. Crucial to this kind of approach is the choice of the smoothing factor. We provide various theoretical analysis on that choice and propose an annealing algorithm to iteratively minimize a less and less smoothed approximation of the measure of interest. Results on the Letor benchmark datasets show that the proposed algorithm achieves state-of-the-art performances.     

Measuring teachers’ self-efficacy beliefs: Development and use of the TEBS-Self

This paper distinguishes between teacher efficacy and teacher self-efficacy beliefs and describes a need for theory and research-based measures of teachers’ self-efficacy beliefs that are grounded in the context of the classroom. To meet this need, a new measure of teacher self-efficacy beliefs, the Teachers’ Efficacy Beliefs System-Self (TEBS-Self), is described by the authors. Principal components analysis results are presented from three independent studies performed in the United States (n=2373 K-6 teachers) using the TEBS-Self.     

Firm technological responses to regulatory changes: A longitudinal study in the Le Mans Prototype racing

Despite the critical role of regulations on competition and innovation, little is known about firm responses and related effects on performance under regulatory contingencies that are permissive or restrictive. By longitudinally investigating hybrid cars competing in the Le Mans Prototype racing (LMP1), we counter-intuitively suggest that permissive regulations increase technological uncertainty and thus decrease the firms’ likelihood of shifting their technological trajectory, while restrictive regulations lead to the opposite outcome. Further, we suggest that permissive regulations favour firms that innovate their products by sequentially upgrading core and peripheral subsystems, while restrictive regulations (in the long term) favour firms upgrading them simultaneously. Implications for theory and practice are discussed.