Context sensitivity of conditioned suppression following preexposure to the conditioned stimulus

Conditioned suppression in rats is often unaffected when the context (or set of background stimuli) is changed following conditioning. This suggests that responding to the conditioned stimulus (CS) can be relatively insensitive to the context in which the CS is presented. In two experiments, we examined whether sensitivity to contextual stimuli is affected by preexposure to the CS. In Experiment 1, when the CS was novel at the outset of conditioning, conditioned suppression was not affected when the context was changed following conditioning. However, when the CS had been preexposed, responding was weaker when extinction occurred outside of the conditioning context. In Experiment 2, responding was again sensitive to the test context, regardless of whether preexposure occurred in the conditioning context or in an alternate context. These results suggest that the extent to which responding is sensitive to context can depend on the conditioning history of the CS.     

Introducing the use of a semi-structured video diary room to investigate students’ learning experiences during an outdoor adventure education groupwork skills course

Outdoor adventure education courses are used in higher education to develop transferable skills such as groupwork and problem-solving skills. There is a need for exploratory investigation into students’ perceptions of this experience. This study aimed to develop an innovative qualitative data collection method, and to use it to explore students’ perceived learning processes and developmental outcomes when taking part in an outdoor groupwork skills course. Participants (n = 40) were undergraduate engineering students who were taking part in the 3 day residential course as part of their degree course. Students’ experiences were captured whilst immersed in the course, using a semi-structured video diary room. Participants entered the diary room at different time points throughout the course and responded to openended questions. Following a thematic analysis, students were found to arrive on the course with mixed feelings towards groupwork and expected learning outcomes. Activities were enjoyable yet challenging, revealing students’ weaknesses and demanding a range of skills and coping methods. The outdoor environment added novelty, risk and natural consequences. Students reported developing a range of skills in groupwork, adaptability, persistence, planning, problem-solving, time-management, communication, leadership, cooperation, group reflection and team spirit, as well as benefits to physical activity, self-confidence, self-awareness, peer and staff relationships and internationalisation. These findings provide a base for future investigation into the long-term impact on student development and skill transfer. The semi-structured video diary room yielded rich data, contributing to the literature by offering a simple, yet effective, qualitative research method that can be implemented in a variety of contexts.     

Lack of reinstatement of an extinguished taste aversion

Three experiments with rat subjects were designed to investigate the possibility that an extinguished saccharin aversion might be reinstated if the animals are made ill with lithium chloride (in the absence of saccharin) following extinction. Although reinstatement can be obtained when the unconditioned stimulus is presented following the extinction of other kinds of conditioned behaviors, the present experiments provided no evidence that an extinguished taste aversion can be reinstated. No reinstatement was observed, even when the aversion had been only partially extinguished and when multiple injections of lithium chloride were administered in an attempt to reinstate the aversion.     

The diffusion of moisture in sorbent solids part II. activated alumina

Ordinary and thermal diffusion of moisture in activated alumina are investigated using a new diffusion cell design and scheme of analysis reported earlier. The specific form of the mass flux equation has a pronounced effect on the magnitude of the associated thermal diffusion ratio. In the case of activated alumina-moist air, if a partial pressure gradient is used, then the thermal diffusion term is small if not zero.Free, Knudsen and surface diffusion all play a part in the diffusion through activated alumina. However, surface diffusion makes the major contribution and for this reason the model in this case can be simplified to a two parameter surface model.The activation energy for surface diffusion is constant and is approximately equal to the mean isosteric heat of absorption. In addition, mean pore radius, turtuosity, and other physical constants are computed from the least square fit of experimental data. Furthermore, the model is theoretically consistent over the entire concentration range (0≦ C_A ≦ C_Asat).A new fact about activated alumina (Grade F1) it that it does not transfer moisture in a nonisothermal condition so long as the partial pressures of moisture on the two sides of the pellet are the same. There appears to be no previous report of this fact in the periodical literature.     

Resistive pulse sensing of magnetic beads and supraparticle structures using tunable pores

Tunable pores (TPs) have been used for resistive pulse sensing of 1 μm superparamagnetic beads, both dispersed and within a magnetic field. Upon application of this field, magnetic supraparticle structures (SPSs) were observed. Onset of aggregation was most effectively indicated by an increase in the mean event magnitude, with data collected using an automated thresholding method. Simulations enabled discrimination between resistive pulses caused by dimers and individual particles. Distinct but time-correlated peaks were often observed, suggesting that SPSs became separated in pressure-driven flow focused at the pore constriction. The distinct properties of magnetophoretic and pressure-driven transport mechanisms can explain variations in the event rate when particles move through an asymmetric pore in either direction, with or without a magnetic field applied. Use of TPs for resistive pulse sensing holds potential for efficient, versatile analysis and measurement of nano- and microparticles, while magnetic beads and particle aggregation play important roles in many prospective biosensing applications.     

Evaluating epistemic uncertainty under incomplete assessments

The thesis of this study is to propose an extended methodology for laboratory based Information Retrieval evaluation under incomplete relevance assessments. This new methodology aims to identify potential uncertainty during system comparison that may result from incompleteness. The adoption of this methodology is advantageous, because the detection of epistemic uncertainty – the amount of knowledge (or ignorance) we have about the estimate of a system’s performance – during the evaluation process can guide and direct researchers when evaluating new systems over existing and future test collections. Across a series of experiments we demonstrate how this methodology can lead towards a finer grained analysis of systems. In particular, we show through experimentation how the current practice in Information Retrieval evaluation of using a measurement depth larger than the pooling depth increases uncertainty during system comparison.     

Teaching and Learning Science for Transformative, Aesthetic Experience

Drawing from the Deweyan theory of experience (1934, 1938), the goal of teaching and learning for transformative, aesthetic experience is contrasted against teaching and learning from a cognitive, rational framework. A quasi-experimental design was used to investigate teaching and learning of fifth grade science from each perspective across an entire school year including three major units of instruction. Detailed comparisons of teaching are given and pre and post measures of interest in learning science, science identity affiliation, and efficacy beliefs are investigated. Tests of conceptual understanding before, after, and one month after instruction reveal teaching for transformative, aesthetic experience fosters more, and more enduring, learning of science concepts. Investigations of transfer also suggest students learning for transformative, aesthetic experiences learn to see the world differently and find more interest and excitement in the world outside of school.     

The effects of reading speed and reading patterns on the understanding of text read from screen

With increasing use of the World Wide Web, rapid scanning or skimming of material on screen has become a frequent activity. However, the outcome of this method of reading has not been thoroughly investigated. Using a range of question types, comprehension was measured after reading from screen at both a normal and fast reading speed. In addition, by automatically recording how readers scrolled through each document, reading patterns were explored. A speed‐accuracy trade‐off was found and, in general, the recall of specific details was less accurate than responses to ‘higher order’ questions. However, questions that addressed the structure of the text were hardest. Analysis of the scrolling movements showed that the overall time spent pausing between movements was the best predictor of comprehension. At a normal reading speed, the most effective readers, in terms of higher comprehension scores, were those who spent more time between scrolling movements, which were fast and frequent.