Managing error on the open road: The contribution of human error models and methods

Despite the provision of various theoretical models and error management methods, error and error-causing conditions remain omnipresent within road transport. This article presents a review of human error models and selected error management approaches, and their applications in a road transport context. The review indicates that such applications, although extant, are limited, and that, compared to other domains, the impact of the models and methods discussed has been only minimal. Reasons for this are discussed, and potential ways in which the models and methods can contribute to road safety are proposed. In conclusion, it is argued that human error models and management methods, although already well integrated within most safety critical domains, still have much to offer to the enhancement of road safety. Further, it is argued that advances in the area, in terms of theoretical and methodological development and validation, are still to be made, and that applications of the error management methods discussed are required to enable such advances.     

The rise of the eco-preneur and the messy world of environmental innovation

Media and academic debates about the environment have increasingly made reference to the so-called 'eco-preneur' ('green entrepreneur' or 'environmental entrepreneur'). These discussions encourage us to see the potential of such figures to act as drivers of environmental innovation. Their combination of entrepreneurial zeal and green motivations is seen as providing them with the ability to transcend the usual tensions between business and the environment. In academic circles a new literature is beginning to emerge around this perspective, 'eco-preneurship'. In this paper we investigate the usefulness of eco-preneurship for understanding environmental innovation. In particular we ask where this literature, supported by popular images in the media, fixes our gaze when we think about environmental innovation in society. And, crucially, what might we be missing by concentrating our attention on these eco-preneurs? The paper concludes by suggesting that environmental innovation is better understood as an inherently messy and complex institutional process, which cannot be reduced to the psychology of entrepreneurial personalities.     

A field investigation of scrounging in semipalmated sandpipers

Animals that forage in groups can produce their own food patches or scrounge the food discoveries of their companions. Mean tactic payoffs are expected to be the same at equilibrium for phenotypically equal foragers. Scrounging is also typically viewed as a risk-averse foraging strategy that provides a more even food intake rate over time. The occurrence of scrounging and the payoffs from different foraging modes have rarely been investigated in the field. Over two field seasons, I examined patch sharing in semipalmated sandpipers (Calidris pusilla) foraging on minute food items at the surface of the substrate. Birds could find patches on their own, a producing event, or join the food patches discovered by others, a scrounging event. I found that the average search time per patch did not differ between producing and scrounging but that the average time spent exploiting a patch was reduced nearly by half when scrounging. As a result, the proportion of time spent exploiting a patch, a measure of foraging payoffs, was significantly lower when scrounging. The variance in payoffs was similar for producing and scrounging. When producing their own patches, individuals that scrounged spent the same proportion of time exploiting a patch as those that only produced. However, within the same individuals, the search time for a scrounged patch was longer than the search time for a produced patch. The results show unequal payoffs for producing and scrounging in this system and suggest that low success in finding patches elicited scrounging.     

Impact of Animal Welfare on Costs and Viability of Pig Production in the UK

The European Union welfare standardsfor intensively kept pigs have steadilyincreased over the past few years and areproposed to continue in the future. It isimportant that the cost implications of thesechanges in welfare standards are assessed. Theaim of this study was to determine theprofitability of rearing pigs in a range ofhousing systems with different standards forpig welfare. Models were constructed tocalculate the cost of pig rearing (6–95 kg) in afully-slatted system (fulfilling minimum EUspace requirements, Directive 91630/EEC); apartly-slatted system; a high-welfare,straw-based system (complying with the UK-basedRoyal Society for the Prevention of Cruelty toAnimals, Freedom Food standards) and afree-range system. The models were also used toassess the consequences of potential increasesin space allowance, and to estimate the cost ofrearing pigs under organic standards.The cost of rearing pigs ranged from92.0 p/kg carcass weight (cw) and 94.6 p/kgcw forthe partly-slatted and fully-slatted systems,to 98.8 p/kgcw and 99.3 p/kgcw for the FreedomFood and free-range systems respectively. Whenspace allowance was increased by 60% to levelsin a recent proposal to revise pig welfareDirective (91/630/EEC), the rearing costs wereunchanged for the free-range system but rose by4.6 p/kgcw for the fully-slatted system. Rearingcosts under organic standards were 31% higherthan in the free-range system. These resultssuggest that improved pig welfare can beachieved with a modest increase in costAt present, price premiums received for meatproduced under high welfare systems in the UKoffset the higher costs of production in thesesystems. To ensure profitability in the longterm, it is important that these premiums aremaintained.     

The reversible process concept applied to the environmental management of large river systems

The wetland ecosystems occurring within alluvial floodplains change rapidly. Within the ecological successions, the life span of pioneer and transient stages may be measured in several years or decades depending on the respective influences of allogenic (water dynamics, erosion, and deposition) and autogenic developmental processes (population dynamics, eutrophication, and terrestrialization). This article emphasizes the mechanisms that are responsible for the ecosystem changes and their importance to environmental management. Two case studies exemplify reversible and irreversible successional processes in reference to different spatial and temporal scales. On the scale of the former channels, the standing-water ecosystems with low homeostasis may recover their previous status after human action on the allogenic processes. On the scale of a whole reach of the floodplain, erosion and deposition appear as reversible processes that regenerate the ecological successions. The concepts of stability and reversibility are discussed in relation to different spatiotemporal referential frameworks and different levels of integration. The reversible process concept is also considered with reference to the energy inputs into the involved subsystems. To estimate the probability of ecosystem regeneration or the cost of restoration, a concept of degrees of reversibility is proposed.     

Climate change impacts in the Middle East and Northern Africa (MENA) region and their implications for vulnerable population groups

Regional Environmental Change - The Middle East and North Africa (MENA) region emerges as one of the hot spots for worsening extreme heat, drought and aridity conditions under climate change. A...     

Regulation of reproduction by dominant workers in bumblebee (Bombus terrestris) queenright colonies

The mechanisms of regulating worker reproduction in bumblebees were studied by direct behavioral observations and by measuring ovarian development and juvenile hormone (JH) biosynthesis rates in workers under different social conditions. Workers in the last stage of Bombus terrestris colony development (the competition phase) had the lowest ovarian development and JH biosynthesis rates. Callows introduced into colonies immediately after queen removal (dequeened colonies) demonstrated a significant increase in ovarian development before, but not during, the competition phase. These findings differ from the higher ovarian development in colonies during the competition phase predicted by the prevailing hypothesis that worker reproduction starts in response to a decrease in queen inhibition. Reproduction of callows housed with dominant workers in small queenless groups was inhibited as in queenright colonies. This suggests that the reduced ovarian development and JH biosynthesis rates observed in dequeened and normally developing colonies during the competition phase also reflect inhibition by dominant workers. Thus, two distinct stages of inhibition of reproduction seem to exist: (1) before the competition phase, when the queen slows down worker ovarian development and prevents oviposition; (2) during the competition phase, when dominant workers inhibit ovarian development of other workers. Between these stages there seems to be a temporal “window” of enhanced worker reproductive development. The queen's typical switch to haploid egg production was not associated with changes in worker ovarian development or JH biosynthesis rates. These findings suggest that regulation of worker reproduction in B. terrestris is not determined by simple changes in the queen's inhibition capacity or by the sex of offspring and that the worker's role is more important than previously believed. Received: 18 March 1998 / Accepted after revision: 18 July 1998