Teachers as mediators: an exploration of situated English teaching

Within the context of lower secondary English teaching in South West England, this study identifies in broad terms the competing goals between which English teachers mediate and the explicit and hidden tensions that result. To understand the interactions of competing goals, teachers’ goal-oriented behaviours are referenced to a set of idealised ‘role types’ based on the dimensions of goals, norms, discourses and practices. It is asserted that competing goals, significant to particular educational circumstances, emanate from various sometimes contradictory local, national and perhaps broader social and cultural influences on practice. Yet the teachers observed moved smoothly between goal-oriented behaviours in a continuous and comfortable style, easily and without reflecting any tensions between them. Thus, this article elaborates an account of situated English teaching

Bistable Gradient Networks II: Storage Capacity and Behaviour Near Saturation

We examine numerically the storage capacity and the behaviour near saturation of an attractor neural network consisting of bistable elements with an adjustable coupling strength, the Bistable Gradient Network (BGN). For strong coupling, we find evidence of a first-order "memory blackout" phase transition as in the Hopfield network. For weak coupling, on the other hand, there is no evidence of such a transition and memorized patterns can be stable even at high levels of loading. The enhanced storage capacity comes, however, at the cost of imperfect retrieval of the patterns from corrupted versions.Comment: 15 pages, 12 eps figures. Submitted to Phys. Rev. E. Sequel to cond-mat/020356

Time-Resolved Temperature Measurements in a Shock Tube Facility

This paper presents non-intrusive, time-resolved temperature measurements in the post-shock flow within a shock tube. We detail the technique, characterise its sensitivity to noise at various pressures, and present temperature measurements after the incident shock wave. Comparisons of experimental measurements with analytical correlations show good agreement with calculated post-shock temperatures at measurement rates of 1 kHz, but systematic errors occur at scan frequencies of 3 kHz, due to the limited bandwidth of our current detector system

Phase locking below rate threshold in noisy model neurons

The property of a neuron to phase-lock to an oscillatory stimulus before adapting its spike rate to the stimulus frequency plays an important role for the auditory system. We investigate under which conditions neurons exhibit this phase locking below rate threshold. To this end, we simulate neurons employing the widely used leaky integrate-and-fire (LIF) model. Tuning parameters, we can arrange either an irregular spontaneous or a tonic spiking mode. When the neuron is stimulated in both modes, a significant rise of vector strength prior to a noticeable change of the spike rate can be observed. Combining analytic reasoning with numerical simulations, we trace this observation back to a modulation of interspike intervals, which itself requires spikes to be only loosely coupled. We test the limits of this conception by simulating an LIF model with threshold fatigue, which generates pronounced anticorrelations between subsequent interspike intervals. In addition we evaluate the LIF response for harmonic stimuli of various frequencies and discuss the extension to more complex stimuli. It seems that phase locking below rate threshold occurs generically for all zero mean stimuli. Finally, we discuss our findings in the context of stimulus detection

Health-related motor testing of children in primary school: A systematic review of criterion-referenced standards

Being physically fit in younger years prevents several diseases in the presence as well as in the life course. Therefore, monitoring physical fitness and motor competence through motor testing is essential for determining developmental status and identifying health-related risks. The main objectives of this systematic review were (1) to identify currently available health-related criterion-referenced standards and cut-off points for physical fitness and motor competence test items, (2) to frame the methodological background on setting health-related criterion-referenced standards and (3) to give implications for a health-related evaluation system for physical fitness and motor competence tests. The electronic data base search (PubMed, Web of Science and SURF) yielded 2062 records in total and identified six empirical studies reporting cut-off points of motor test items for children (7–10 years), as well as 30 methodological papers discussing determination approaches to health-related criterion-referenced standards. Data collection, selection and analyses followed the PRISMA guidelines. Health-related motor test standards need to be gender- and age-specific but should refer to an absolute cut-off point rather than to relative performance in the reference group. Due to the lack of data on health-related criterion referenced standards, receiver-operating-characteristic (ROC) curves provide a tool for the determination of cut-off points and criterion referenced standards for physical fitness and motor competence tests. A standardized approach forms the fundamental base for a globally applicable evaluation of health-related fitness tests

Managing patient expectations at emergency department triage

Emergency departments (ED) overcrowding, long wait, and uncomfortable waiting room conditions may lower perceived quality of the patient experience and satisfaction. This study investigates the relationship between patient satisfaction and communication of expected wait times, at the point of triage. A pre-post (11/4/ 2008 – 2/5/2009) group design with convenience sample (n=1,209) of all discharge adult ED patients was utilized for this study. A static expected wait time model (i.e., average wait time + one standard deviation) based on time of the day, day of the week and triage levels was employed to communicating expected wait time at triage while an in-house survey with five-point Likert-scale patient satisfaction questions (satisfied with wait time in triage, informed about delays, and overall rating of ED visit) was administrated at the discharge desk. The communication of delays intervention was significant for only overall rating of ED, while binary communication status was significantly associated with all three patient satisfaction questions. The patients who didn’t receive any communication about delays, were between 1.42 to 5.48 times more likely to rate the three satisfaction questions lower than very good. With communication about delays, the percentage of patients responding very good and very poor/poor were 14.6% higher and 5.9% lower, respectively, for the satisfied with wait time in triage question. Although communication of delays intervention was not significant, the patients who received wait times information were significantly more satisfied. This indicates that patients are more likely to accept longer wait times provided their expectations are managed via communication. Future studies should explore technological solutions for communication of delays and operational improvement initiatives along with alignment of incentives for ED staff to further improve the patient experience. Experience Framework This article is associated with the Culture & Leadership lens of The Beryl Institute Experience Framework. (http://bit.ly/ExperienceFramework) Access other PXJ articles related to this lens. Access other resources related to this len

Life extension of structural components via an improved nondestructive testing methodology

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 337-355).An experimental study was performed to determine the flaw detection sensitivity of advanced nondestructive testing (NDT) techniques with respect to structural applications. The techniques analyzed exemplify the incorporation of digital technology into NDT and includes the following: meandering winding magnetometer array (MWM-array@) eddy current, phased-array ultrasonic (PA-UT), three dimensional computed tomography (3DCT), and digital radiography (DR). The three classes of samples inspected with these techniques consisted of alloy block specimens containing flat bottom hole (FBH) arrays, probability of detection (POD) wedding cake samples, and actual airplane engine components. Results from the sensitivity analyses were compared to current NDT techniques used industrially. An image analysis program called Cellprofiler was used to optimize the threshold correction factor for selected results. The Cellprofiler output was analyzed in conjunction with POD software, and the integration of digitally advanced NDT techniques with image analysis software resulted in approximately a threefold improvement in the minimum detectable flaw size at the 90/95 POD/CL level. An improved inspection methodology was presented which incorporated redundancy in the in-service inspection plan with the use of Bayesian updating techniques to forecast remnant life. Reliability block diagrams for structural disk and blade aircraft engine components were presented as examples of the methodology. Implementation of the proposed NDT methodology significantly increases the feasibility of a retirement-forcause (RFC) approach to be applied to aging structural components in a cost-effective manner.by Brian P. Hohmann.Sc.D

Mechanical behavior of dip-brazed aluminum sandwich panels

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2007."February 2007." Vita.Includes bibliographical references (leaves 158-160).An experimental study was carried out to determine the mechanical behavior of sandwich panels containing cellular cores of varying shape. Compression and four point bend tests were performed on sandwich panels with square and triangular honeycomb cores. These honeycombs were made of perforated aluminum sheet of repeating diamond and hexagonal patterns. The sandwich panel assemblies were joined via dip brazing. Defects were introduced into some panels to quantify the effect on strength and stiffness. Hybrid sandwich panels, consisting of foam material in the void spaces of the square and triangular cells were evaluated for the effect on the defect tolerance of the structures. The results showed that sandwich panels with diamond shaped cores had compressive strengths approximately four times greater than hexagonal shaped cores. In four point bending the diamond cores were approximately twice as stiff as cores made from hexagonal patterned sheet. The introduction of defects lowered strength by about 30% for diamond cores in compression, and about 15% for hexagonal cores. In four point bending this strength reduction was not as significant due to shear stresses damaging periodicity at a faster rate than in compression.(cont.) The use of foam within the cells resulted in higher absolute peak compression and flexure loads, however the Load/Density ratios demonstrated cases where the added weight of the foam did not result in a better panel. A difference of nearly an order of magnitude between the highest and lowest compressive and flexure loads is evident when the presence of defects and foam are taken into account.by Brian P. Hohmann.S.M