Determinants of a GP visit and cervical cancer screening examination in Great Britain.

Objective: In the UK, women are requested to attend a cervical cancer test every 3 years as part of the NHS Cervical Screening Programme. This analysis compares the determinants of a cervical cancer screening examination with the determinants of a GP visit in the same year and investigates if cervical cancer screening participation is more likely for women who visit their GP. Methods: A recursive probit model was used to analyse the determinants of GP visits and cervical cancer screening examinations. GP visits were considered to be endogenous in the cervical cancer screening examination. The analysed sample consisted of 52,551 observations from 8,386 women of the British Household Panel Survey. Results: The analysis showed that a higher education level and a worsening self-perceived health status increased the probability of a GP visit, whereas smoking decreased the probability of a GP visit. GP visits enhanced the uptake of a cervical cancer screening examination in the same period. The only variables which had the same positive effect on both dependent variables were higher education and living with a partner. The probability of a cervical cancer screening examination increased also with previous cervical cancer screening examinations and being in the recommended age groups. All other variables had different results for the uptake of a GP visit or a cervical cancer screening examination. Conclusions: Most of the determinants of visiting a GP and cervical cancer screening examination differ from each other and a GP visit enhances the uptake of a smear test

Individual differences in first- and second-order temporal judgment

The ability of subjects to identify and reproduce brief temporal intervals is influenced by many factors whether they be stimulus-based, task-based or subject-based. The current study examines the role individual differences play in subsecond and suprasecond timing judgments, using the schizoptypy personality scale as a test- case approach for quantifying a broad range of individual differences. In two experiments, 129 (Experiment 1) and 141 (Experiment 2) subjects completed the O-LIFE personality questionnaire prior to performing a modified temporal-bisect ion task. In the bisection task, subjects responded to two identical instantiations of a luminance grating presented in a 4deg window, 4deg above fixation for 1.5 s Experiment 1) or 3 s (Experiment 2). Subjects initiated presentation with a button- press, and released the button when they considered the stimulus to be half-way through (750/1500 ms). Subjects were then asked to indicate their ‘most accurate estimate’ of the two intervals. In this way we measure both performance on the task (a first-order measure) and the subjects’ knowledge of their performance (a second-order measure). In Experiment 1 the effect of grating-drift and feedback on performance was also examined. Experiment 2 focused on the static/no-feedback condition. For the group data, Experiment 1 showed a significant effect of presentation order in the baseline condition (no feedback), which disappeared when feedback was provided. Moving the stimulus had no effect on perceived duration. Experiment 2 showed no effect of stimulus presentation order. This elimination of the subsecond order-effect was at the expense of accuracy, as the mid-point of the suprasecond interval was generally underestimated. Response precision increased as a proportion of total duration, reducing the variance below that predicted by Weber’s law. This result is consistent with a breakdown of the scalar properties of time perception in the early suprasecond range. All subjects showed good insight into their own performance, though that insight did not necessarily correlate with the veridical bisection point. In terms of personality, we found evidence of significant differences in performance along the Unusual Experiences subscale, of most theoretical interest here, in the subsecond condition only. There was also significant correlation with Impulsive Nonconformity and Cognitive Disorganisation in the sub- and suprasecond conditions, respectively. Overall, these data support a partial dissocation of timing mechanisms at very short and slightly longer intervals. Further, these results suggest that perception is not the only critical mitigator of confidence in temporal experience, since individuals can effectively compensate for differences in perception at the level of metacognition in early suprasecond time. Though there are individual differences in performance, these are perhaps less than expected from previous reports and indicate an effective timing mechanism dealing with brief durations independent of the influence of significant personality trait differences

On the contingent valuation of mortality risk reduction in developing countries

Using the contingent valuation method in developing countries to value mortality risk reduction is particularly challenging because of the low level education of the respondents. In this article, we investigate whether some brief training regarding probability and risk concepts has any significant effect on the willingness-to-pay (WTP) responses. We elicit individuals’ risk perceptions by providing information on age specific mortality risks and find that people on average overestimate the mortality risk at younger ages and underestimate it at older ages. Our results indicate a significantly higher WTP for the trained sub-sample and WTP is sensitive to the magnitude of risk reduction for both the sub-samples.

Health damage of air pollution and benefits and costs of ammonia control in the Netherlands

The paper gives a benefit-cost analysis of ammonia emission control policy in TheNetherlands. Particular care has been given to calculation of the health benefits. Adose-response relationship between air pollution and the number of work loss dayshas been estimated by applying the one-way fixed-effects method to data on workloss days due to illness and average year concentrations of air pollution in 29districts. A significant relationship is found between ammonia (NH3) and thenumber of work loss days (WLDs) and also for sulphate aerosol(SO4). The dose-responserelationship for ammonia has been used to calculate the health benefits ofreducing ammonia deposition in The Netherlands in the periods 1987-1995 and1995-2000. Together with information on other benefits and costs of ammoniaemission control the health benefits are incorporated in a benefit-cost analysis ofrecent and current ammonia control policy in The Netherlands. The benefit cost ratioturns out to be 1/3 from a national point of view and 2/3 if transfrontier benefits areincluded.

Development Of The Science Of Thermodynamics

[No abstract available]The author is grateful to the Turkish Academy of Sciences for financial support and to his assistant Berk Cevrim for participation in editing

{SLD}-Resolution Reduction of Second-Order {H}orn Fragments

We present the derivation reduction problem for SLD-resolution, the undecidable problem of finding a finite subset of a set of clauses from which the whole set can be derived using SLD-resolution. We study the reducibility of various fragments of second-order Horn logic with particular applications in Inductive Logic Programming. We also discuss how these results extend to standard resolution

On the willingness to pay to reduce risks of small losses

Willingness to pay, Small loss, Risk aversion, Background risk, D81,