Social impacts of road traffic: perceptions and priorities of local residents

The assessment of the social impacts of road traffic is usually based on objective indicators or on expert judgement, without input from the affected communities. This paper considers the perceptions and priorities of local residents about traffic impacts and possible mitigation measures, using as a case study a rural area that will be affected by traffic associated with the construction of a nuclear power station. The study consisted of a qualitative phase followed by a stated preference survey. Econometric models were used to measure the relative priority of different impacts and mitigation measures. The most impactful aspects were noise, vibration and increased car or bus travel times. The most preferred measures were night-time restrictions to HGVs, parking restrictions and safety measures for pedestrians and cyclists. There were significant differences in preferences according to residence location, gender, employment status and household composition. The results provide information about aspects that tend to be aggregated in existing assessment frameworks, separating the reduction in the utility of some activities (like walking and driving) and the suppression of those activities.     

Factors influencing the national distribution of polycyclic aromatic hydrocarbons and polychlorinated biphenyls in British soils

The polycyclic aromatic hydrocarbons (PAHs) naphthalene, acenaphthylene, acenaphthene, fluorene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, ideno[1,2,3,-cd]-pyrene, dibenz[a,h]anthracene, benzo[g,h,i]perylene and the polychlorinated biphenyls (PCBs) 8, 18, 28, 29, 31, 52, 77, 101, 105, 114, 118, 123, 126, 128, 138, 141, 149, 153, 156, 157, 163, 169, 170, 171, 180, 183, 187, 189, 194, 199, 201, 206, and 209 were measured in -200 rural soils across Great Britain (GB). Dominance of soil PAH profiles by heavier compounds (4-6 rings) provided initial evidence for the importance of source in governing soil PAH concentrations. No relationship was found between soil organic matter (SOM) and sum concentration of total and "heavy" PAHs, although there was a weak positive relationship with lighter compounds. A spatial statistical technique showed that highest soil PAH concentrations were usually found close to industrial/urban centers where presumably source intensity is highest. PCBs clustered into seven groups, five of which contained a single "dioxin like" PCB, one contained lighter congeners (2-4 chlorines), and one contained heavy congeners (5-10 chlorines). Linear regressions with SOM explained up to 24.3% of variation for the sum concentration of penta- to deca- congeners, but <1% for the lighter congener groups. No significant relationships were found with latitude. Spatial statistical techniques showed clusters of high soil PCB concentrations predominantly in west and south east GB, either associated with urbanized areas or on the West coast.     

Dynamic page based crossover in linear genetic programming

Page-based linear genetic programming (GP) is proposed in which individuals are described in terms of a number of pages. Pages are expressed in terms of a fixed number of instructions, which is constant for all individuals in the population. Pairwise crossover results in the swapping of single pages, and thus, individuals are of a fixed number of instructions. Head-to-head comparison with Tree-structured GP and block-based linear GP indicates that the page-based approach evolves succinct solutions without penalizing generalization ability.     

Retinal detachment in the rat

Retinal detachment is uncommon in the rat. Retinal atrophy, rosette formation and folding of the retina are some of the sequelae following reattachment.     

Sequential entry and merger in spatial price discrimination

This paper newly introduces sequential entry into previous models of spatial price discrimination that examine location choices made in anticipation of a potential merger. While merger with simultaneous entry routinely reduces social welfare, we show that mergers frequently improve welfare. The extent of welfare improving mergers varies inversely with the timing advantage of an excluded rival. When the rival locates alone in the first stage, the merger harms welfare. When the rival locates alone in the last stage, the merger improves welfare. These results hold true when allocating three firms across either two or three location stages. Thus, allowing staged entry dramatically alters and often reverses the conclusion previously drawn on the basis of simultaneous entry.     

Poverty and disrepair: Challenging the myth of ignorance in private sector housing

As private home ownership grows in Europe, so do the problems of maintenance and repair for poorer owners. In England, it has been believed that one obstacle is the owners' apparent satisfaction with poor conditions. This paper deconstructs the questions in the English House Condition Survey 1981 on which that assumption has been based. By reference to other EHCSs and to a research methodology offering a more differentiated approach to establishing residents' views, it suggests that the problem is not ignorance at all. A more subtle understanding of the validity of housing satisfaction questionnaires is needed to develop effective policies of urban renewal.     

Coherent Optical Recognition and Counting of Reticulated Red Blood Cells

A coherent optical data-processing system for identifying and counting blood cells has been developed. Optical Weiner-Kolmogorov (minimum mean-square error) linear filtering is employed to estimate the density per unit area of a given cell type present in a sample blood smear. The Weiner filter is designed to recognize the characteristics of an ensemble of cells of a type rather than specific individual cells. In this way the system is made insensitive to minor variations in shape, size, or orientation of the cells. A Poisson shot-noise model for blood cells as a spatial random process is employed to calculate the far-field scattering from the cells. Results of experiments in which the percentage of reticulated (immature) red cells present in a smear has been determined are presented. The identification and counting accuracies compare favorably with those obtained by laboratory technicians with a microscope. The potential time saving of instantaneous estimation for the entire smear is significant.