Harold H. Kelley (1921-2003).

This obituary reports the death of Harold Harding Kelley, Professor Emeritus of Psychology at University of California (1921-2003). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Towers on the steppe: compact city plans and local perceptions of urban densification in Ulaanbaatar,Mongolia

This paper examines how plans for urban densification, particularly those supported by international organisations, intersect with local residents’ perceptions of housing and land use in the developing world. The study focuses on ger districts in Ulaanbaatar, the site of numerous plans for large-scale urban transformation. Ger districts are rapidly growing areas named for the felt tents that are considered their typical housing mode. This study interviewed 120 ger district residents across central, middle and outer areas of the city. The results reveal migration patterns different from those typically reported, with the highest proportions of migrants and renters living in the central district. Interviewees generally held positive views of apartment living, while preferring low-density land use. Residents’ views of density were strongly influenced by Mongolian attitudes to land and open space. The paper concludes by discussing the reasons for, and consequences of, residents’ and international policy-makers’ different framings of urban density.     

Hypermedia and learning: Contrasting interfaces to hypermedia systems

This study explores selected theoretical and design issues associated with the use of hypermedia learning environments to promote the recall, synthesis, integration and retention of information. The study contrasts two different hypermedia systems that contain resources on a complex historical domain. The experimental condition incorporates design features related to complexity, context-dependency and interconnectedness in order to highlight different aspects of its instructional content. The experimental condition was hypothesized to foster greater achievement on tests for synthesis, integration and retention of knowledge and to be more favorably rated by users. The control condition incorporates simple linear design features including several features that are antithetical to those of the experimental condition. The control condition presents the same instructional content in a more rigid and decontextualized manner and was hypothesized to foster greater mastery of factual recall but less synthesis, integration and retention of knowledge. Results however demonstrated that participants in the control condition were able to recall more facts, make more connections between themes in the test for synthesis and retain more facts than participants in the experimental condition. However, differences in overall performance for both hypermedia systems were not statistically significant: neither system had a different effect on learning.     

Comparison of the reinforcing and anxiogenic effects of intravenous cocaine.

People report that ethanol improves the experience produced by cocaine. This effect may be attributable to cocaethylene (CE), a cocaine metabolite formed only in the presence of ethanol. To test this, rats were trained to run an alley for a single intravenous dose of either cocaine (0.5–2.0 mg/kg) or an equimolar dose of CE (0.75–2.88 mg/kg). The rats' start latency and running speed measured the reinforcing effects of the drugs and the number of times rats approached but failed to enter the goal box (i.e., approach-avoidance retreats) indexed anxiety. Rats reinforced with CE had shorter start latencies and faster running speeds and exhibited fewer "retreats" than cocaine-reinforced rats. These results suggest that CE is more reinforcing and less anxiogenic than cocaine and hence may account for the combined effects of cocaine and ethanol in humans. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Technological learning in bioenergy systems

The main goal of this article is to determine whether cost reductions in different bioenergy systems can be quantified using the experience curve approach, and how specific issues (arising from the complexity of biomass energy systems) can be addressed. This is pursued by case studies on biofuelled combined heat and power (CHP) plants in Sweden, global development of fluidized bed boilers and Danish biogas plants. As secondary goal, the aim is to identify learning mechanisms behind technology development and cost reduction for the biomass energy systems investigated. The case studies reveal large difficulties to devise empirical experience curves for investment costs of biomass-fuelled power plants. To some extent, this is due to lack of (detailed) data. The main reason, however, are varying plant costs due to differences in scale, fuel type, plant layout, region etc. For fluidized bed boiler plants built on a global level, progress ratios (PRs) for the price of entire plants lies approximately between 90–93% (which is typical for large plant-like technologies). The costs for the boiler section alone was found to decline much faster. The experience curve approach delivers better results, when the production costs of the final energy carrier are analyzed. Electricity from biofuelled CHP-plants yields PRs of 91–92%, i.e. an 8–9% reduction of electricity production costs with each cumulative doubling of electricity production. The experience curve for biogas production displays a PR of 85% from 1984 to the beginning of 1990, and then levels to approximately 100% until 2002. For technologies developed on a local level (e.g. biogas plants), learning-by-using and learning-by-interacting are important learning mechanism, while for CHP plants utilizing fluidized bed boilers, upscaling is probably one of the main mechanisms behind cost reductions.     

Niche accumulation and hybridisation strategies in transition processes towards a sustainable energy system: An assessment of differences and pitfalls

This paper assesses two patterns in transition processes for using them as strategies towards a sustainable energy system, i.e., niche accumulation and hybridisation. Both play important but different roles in transitions. The expected success of these strategies depends on the innovation's history and the innovation context. The different strategies are illustrated with several examples from the energy domain.     

Oxygen consumption during fire suppression: error of heart rate estimation.

Ten male firefighters were tested on a treadmill to determine their heart rate (HR) x oxygen consumption (VO2) relationship. These men then performed a simulated fire suppression protocol during which HR and VO2 were measured simultaneously by a portable physiological monitoring system. Average VO2 in the simulated setting was 31.0 +/- 7.0 ml.kg-1.min-1 at a HR of 176 +/- 9 bpm. This VO2 was significantly (p less than or equal to 0.05) less than the VO2 that would have been predicted by treadmill testing (38.9 +/- 5.0 ml.kg-1.min-1) at a corresponding HR. Fifty-nine per cent of this variability could be accounted for by regression analysis. Firefighters worked on average at 73 +/- 10% VO2 max with a range of 54% to 88%. There was a significant (-0.82; p less than or equal to 0.05) inverse relationship between performance time of the fire suppression protocol and the relative intensity of VO2 max at which the firefighters worked. These findings indicate that the prediction of energy expenditure from HR is not straightforward in fire suppression settings. Furthermore, the relative intensity of work firefighters self-select is variable and should be considered as an additional physiological determinant of work behaviour.