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Florida's weakened motorcycle helmet law: effects on death rates in motorcycle crashes

OBJECTIVES: Effective July 1, 2000, Florida's universal helmet law was amended to exclude riders ages 21 and older with insurance coverage providing at least 10,000 US dollars in medical benefits for injuries sustained in a motorcycle crash. Observed helmet use in Florida was reported to have declined from nearly 100% in 1998, before the law change, to 53% after. This study examined the effects of the law change on the likelihood of death, given involvement in a motorcycle crash. METHODS: Rates of motorcyclist deaths per crash involvement in Florida for 2001-2002 (after the law change) were compared with those for 1998-1999 (before the law change). Before/after death rate ratios (95% CIs) were examined, and logistic regression models estimated the effect of the helmet law change on the odds of death in a crash, while controlling for rider gender, age, and seating position, and number of vehicles. RESULTS: The motorcyclist death rate increased significantly after the law change, from 30.8 to 38.8 deaths per 1,000 crash involvements. Motorcyclist death rates increased for single- and multiple-vehicle crashes, for male and female operators, and for riders of all ages including those younger than 21. After controlling for gender and age, the likelihood of death given involvement in a motorcycle crash was 25% higher than expected after the law change. It is estimated that 117 motorcyclist deaths could have been avoided during 2001-2002 if Florida's universal helmet law had remained in place. CONCLUSIONS: This study provides evidence of the life-saving benefits of universal helmet laws. The results also suggest that age-specific helmet laws are not effective in protecting the youngest drivers. This is not surprising, as these laws are largely unenforceable.     

The risk assessment-policy gap: an example from the UK contaminated land regime

Risk-based regulation assumes that risk assessment can evaluate risks against policy objectives. However, policy goals are often ambiguous and require risk assessors to interpret them for use in risk assessment. This risk assessment-policy gap stems partly from normative and imprecise policy language but is rooted more fundamentally in society's uncertain expectations for the environment. Until this uncertainty is resolved, the democratic and regulatory effectiveness of risk regulation will be undermined by ad hoc policy decisions abdicated to risk assessors.     

Beyond depletion: Daily self-control motivation as an explanation of self-control failure at work

The organizational self-control literature usually applies resource perspectives that explain self-control failure at work by depletion of self-control resources. However, these perspectives neglect the role of self-control motivation. On a daily level, we examine several self-control aspects (resources, motivation, demands, and effort) as predictors of a manifestation of self-control failure at work, namely, daily counterproductive work behavior toward the organization (CWB-O). Additionally, we investigate self-control effort as a mechanism predicting the depletion of self-control resources throughout the day. We analyzed data from 155 employees in a 2-week diary study with 2 daily measurement points. Multilevel path modeling showed that self-control motivation and self-control demands, but not self-control resource depletion, predicted self-control effort. There was an indirect effect from self-control motivation on CWB-O via self-control effort but no indirect effect from self-control demands on self-control resource depletion throughout the day via self-control effort. Findings suggest that self-control motivation is a crucial factor explaining self-control failure at work and cast further doubt on the idea that exerted self-control effort is the only mechanism leading to self-control resource depletion.     

Possible causes of temporal fluctuations in primary production of the microphytobenthos in the Danish Wadden Sea

The effects of prior exposure to unlabelled naphthalene on the processes of uptake, tissue distribution and elimination of [1-¹⁴C] naphthalene by mussels (Mytilus edulis) were examined. Mussels collected from Whitsand Bay (S. W. England) in October 1980 were either held unexposed or exposed to unlabelled naphthalene (0.5 μg 1^?1) for 4 wk, prior to receiving a 4 h pulse of [1-¹⁴C] naphthalene in the medium (7 μg 1^?1). After 4 h exposure to [1-¹⁴C] naphthalene, the major tissues (digestive gland, gills, kidneys, mantle and remaining tissue) showed exponential depuration curves which could be resolved into two statistically significant components. The kinetics of elimination and the biological half-times of [1-¹⁴C] naphthalene in the tissues were determined. Mussels pre-exposed to unlabelled naphthalene had a significantly higher rate of elimination of [1-¹⁴C] naphthalene from the gills and kidneys. These results indicate that the toxicant, naphthalene, is actively excreted from the body by the gills and kidneys and the process is enhanced by prior exposure to the toxicant.     

Divorce in common murres (Uria aalge): relationship to parental quality

Behavioral precursors of 12 divorces were examined in 30 color-banded pairs of common murres (Uria aalge) over six breeding seasons. Common murres are long-lived seabirds that typically return each year to the same mate and nest site in dense colonies. At least one parent is present continuously from egg lay to chick fledging. Murres, therefore, have considerable opportunities to compare their mates parental behavior with that of several familiar neighbors. Previous reproductive success was lower for divorcing birds than for reuniting pairs. As predicted by the better option hypothesis, there were clear choosers (seven females and five males) that initiated divorce by moving to a new birds site or by courting a new partner at their current site. Choosers improved their reproductive success after the divorce, whereas their previous partners, the victims did not. Yearly divorce rates (average 8.2% per year) were significantly correlated with yearly mortality rates. Divorces appear to be opportunistic: pairs divorced after varying numbers of reproductive failures with the immediate precursor usually being the disappearance (death) of a murre from a successful neighboring site. In contrast to the delays experienced by victims, choosers formed new pairs quickly and laid their eggs no later than reuniting pairs. Prior to the divorce, victims fed their chicks less often than choosers, and some engaged in other behaviors that compromised egg or chick survival. These observations suggest that deficiencies in parental behavior were precursors to the divorce. This report is one of the first cases where reproductive failure of divorcing pairs has been linked to deficits in the parental behavior of the subsequent divorce victim.Communicated by C. Brown     

Testosterone treatment suppresses paternal care in superb fairy-wrens, Malurus cyaneus, despite their concurrent investment in courtship

Courtship displays and paternal care in male birds are generally thought to be mutually exclusive, because testosterone, necessary for stimulation of sexual behaviours, suppresses paternal behaviours. Superb fairy-wrens, Malurus cyaneus, are unusual in that males concurrently engage in courtship and paternal care. Fairy-wrens live in stable socially monogamous pairs with 0-4 subordinate male helpers. Both helper and dominant males provide care whenever it is required but continue courtship throughout the period of care as most fertilisations are extra-group and females are multi-brooded. To examine the role of testosterone in this trade-off, we compared testosterone levels in males of different social status, while they had dependent nestlings, and determined the effect of testosterone treatment on provisioning rates of pairs. Testosterone levels were lower in subordinate helpers, although these do not provide more paternal care than dominant males. Conversely, testosterone levels were similar in dominant males with or without helpers, although as the number of helpers increases males invest substantially less in nestling care and more in extra-group courtship. Although testosterone levels are high, irrespective of paternal duties, experimental testosterone treatment of males resulted in a large (65%) reduction in nestling feeding rates. Surprisingly, there was no indication that females compensated for this reduction in provisioning, suggesting that females might assume a constant male contribution to offspring care. We conclude that during nestling provisioning, male fairy-wrens maintain testosterone at an individual level that does not interfere with parental duties, while allowing high investment in extra-group courtship.     

Predator inspection behaviour in minnow shoals: differences between populations and individuals

Summary When minnows (Phoxinus phoxinus) detect a stalking pike (Esox lucius) one of their first responses is to perform inspection behaviour during which individuals or small groups approach the predator. This paper compares the inspection behaviour of two contrasting groups of minnows: Dorset minnows which have been heavily predated by pike for many thousands of years and Gwynedd minnows which have spent an equivalent period of time in a pike free environment. Minnows sympatric with pike inspected a realistic model pike more frequently and in larger shoals. Although they commenced inspection earlier they were more timid and kept a greater distance between themselves and the predator. After an inspection they were less likely to recommence foraging than minnows from the Gwynedd population. Individual differences in inspection found within the two populations suggest that selfish behaviour was present.