Overestimation of Skills Affects Drivers’ Adaptation to Task Demands

Inadequate self-assessment, and specifically, overestimation of skill, results in insufficient adaptation to task demands, which can manifest itself on different levels of the driving task. A total of 130 drivers (83 novice and 47 experienced drivers) participated in an on-road driving assessment. Their performance in this assessment (i.e., fail or pass) was compared to the participants’ reported confidence in their driving skills (i.e., high or low confidence), resulting in three calibration groups: a) well-calibrated drivers (reported confidence matched performance on assessment), b) overconfident drivers (high confidence but failed assessment) and c) insecure drivers (low confidence but passed assessment). Furthermore, participants completed a questionnaire which focused on choices made on the strategic and manoeuvring level of the driving task. No significant difference was found between the calibration groups for the strategic level. Overconfident drivers reported significantly more violating behaviour than the well-calibrated and the insecure drivers. At the manoeuvring level, overconfident drivers showed significantly less instances of adaptation to traffic complexity. In conclusion, the current study suggests that overconfidence is related to inadequate adaptation to task demands

Politiewerking in multiculturele buurten: de beeldvorming bij burgers en agenten over de gemeenschapsgerichte politiezorg

In deze bijdrage wordt een antwoord geformuleerd op de vraag hoe politiemensen omgaan met etnisch-culturele minderheden op basis van data verzameld in het kader van een 34 maand durend beleidsgericht onderzoek naar de toepassing van de gemeenschapsgerichte politiezorg in multiculturele buurten (in opdracht van Federaal Wetenschapsbeleid). Daarbij werden in vijf Belgische politiezones observaties uitgevoerd bij wijk- en interventieagenten die in multiculturele buurten werkzaam zijn. Het onderzoek beoogt inzicht te verwerven in de manier waarop interacties tussen politie en etnisch-culturele minderheden verlopen en de elementen die deze interacties beïnvloeden. Percepties, betekenisverlening en verwachtingen werden in kaart gebracht. Concreet zal de bijdrage ingaan op de beeldvorming over etnische culturele minderheden bij wijk- en interventieagenten met aandacht voor de inhoud ervan, de totstandkoming en de factoren die erop van invloed zijn. Vervolgens wordt de vraag beantwoord in welke mate en op welke manier beelden en attitudes ook het gedrag van de politiemensen op het terrein beïnvloeden met aandacht voor de situationele, contextuele, persoonlijke en organisatorische factoren die daarop van invloed zijn

Adrenergic and myogenic regulation of viscoelasticity in the vascular bed of the human forearm

This study tested the hypothesis that the compliance (C) and viscoelasticity (K) of the forearm vascular bed are controlled by myogenic and/or α-adrenergic receptor (αAR) activation. Heart rate (HR) and waveforms of brachial artery blood pressure (Finometer) and forearm blood flow (Doppler ultrasound) were measured in baseline conditions and during infusion of noradrenaline (NA; αAR agonist), with and without phentolamine (αAR antagonist; n= 10; 6 men and 4 women). These baseline and αAR-agonist-based measures were repeated when the arm was positioned above or below the heart to modify the myogenic stimulus. A lumped Windkessel model was used to quantify the values of forearm C and K in each set of conditions. Baseline forearm C was inversely, and K directly, related to the myogenic load (P \u3c 0.001). Compared with saline infusion, C was increased, but K was unaffected, with phentolanine, but only in the \u27above\u27 position. Compliance was reduced (P \u3c 0.001) and K increased (P= 0.06) with NA infusion (main effects of NA) across arm positions; phentolamine minimized these NA-induced changes in C and K for both arm positions. Examination of conditions with and without NA infusion at similar forearm intravascular pressures indicated that the NA-induced changes in C and K were due largely to the concurrent changes in blood pressure. Therefore, within the range of arm positions used, it was concluded that vascular stiffness and vessel wall viscoelastic properties are acutely affected by myogenic stimuli. Additionally, forearm vascular compliance is sensitive to baseline levels of αAR activation when transmural pressure is low. © 2011 The Physiological Society

Handgrip strength at midlife and familial longevity

Low handgrip strength has been linked with premature mortality in diverse samples of middle-aged and elderly subjects. The value of handgrip strength as marker of "exceptional" human longevity has not been previously explored. We postulated that the genetic influence on extreme survival might also be involved in the muscular strength determination pathway. Therefore, the objective of this study was to assess the muscle strength in a sample of middle-aged adults who are genetically enriched for exceptional survival and comparing them to a control group. We included 336 offspring of the nonagenarian from the Leiden Longevity Study who were enriched for heritable exceptional longevity, and 336 of their partners were used as controls. The Leiden Longevity study was a prospective follow up study of long-living siblings pairs together with their offspring and their partners. Handgrip strength was used as a proxy for overall muscle strength. No significant difference in handgrip strength was seen between the offspring of the nonagenarian and their partners after adjustment for potential confounders including body compositions, sum score of comorbidities, medication use, smoking and alcohol history. The main determinants of midlife handgrip strength were age, gender, total body percentage fat and relative appendicular lean mass. Although midlife handgrip strength has previously been shown to be an important prognostic indicator of survival, it is not a marker of exceptional familial longevity in middleaged adults. This finding suggests that genetic component of susceptibility to extreme survival is likely to be separate from that of muscular strength

The effect of cognitive impairment on the predictive value of multimorbidity for the increase in disability in the oldest old: the Leiden 85-plus Study

Background: prevention of disability is an important aim of healthcare for older persons. Selection of persons at risk is a first crucial step in this process

Randomised Controlled Trial of Unsolicited Occupational Therapy in Community-Dwelling Elderly People: The LOTIS Trial

OBJECTIVE: The objective of this trial, the Leiden 85-Plus Occupational Therapy Intervention Study (LOTIS), was to assess whether unsolicited occupational therapy, as compared to no therapy, can decelerate the increase in disability in high-risk elderly people. DESIGN: This was a randomised controlled trial with 2-y follow-up. SETTING: The study took place in the municipality of Leiden in the Netherlands. PARTICIPANTS: The participants were 402 community-dwelling 85-y-old people, with a Mini-Mental State Examination score of >18 points at baseline. INTERVENTIONS: Participants in the intervention group were visited by an occupational therapist who provided training and education about assistive devices that were already present and who gave recommendations and information about procedures, possibilities, and costs of assistive devices and community-based services. Control participants were not visited by an occupational therapist. OUTCOME MEASURES: The primary outcome measure was the score achieved on the Groningen Activity Restriction Scale. Secondary outcome measures included self-evaluations of well-being and feelings of loneliness. RESULTS: The participants were evenly divided between the two groups: 202 participants were allocated to the intervention group and 200 participants to the control group. Of the 202 participants randomised to occupational therapy, 55 participants declined the proposed intervention. An occupational therapist indicated that of the remaining 147 participants, 66 (45%) needed an occupational therapy intervention. A total of 44 new assistive devices and five community-based services were implemented. During follow-up there was a progressive increase in disability in the intervention group (mean annual increase, 2.0 points; SE 0.2; p < 0.001) and control group (mean annual increase, 2.1 points; SE 0.2; p < 0.001). The increase in disability was not significantly different between study groups (0.08 points; 95% CI, −1.1–1.2; p = 0.75). There was also no difference between study groups for any of the secondary outcome measures. CONCLUSION: Unsolicited occupational therapy in high-risk elderly participants does not decelerate the increase in disability over time

Effects of study design and allocation on participant behaviour-ESDA: study protocol for a randomized controlled trial

Background: What study participants think about the nature of a study has been hypothesised to affect subsequent behaviour and to potentially bias study findings. In this trial we examine the impact of awareness of study design and allocation on participant drinking behaviour. Methods/Design: A three-arm parallel group randomised controlled trial design will be used. All recruitment, screening, randomisation, and follow-up will be conducted on-line among university students. Participants who indicate a hazardous level of alcohol consumption will be randomly assigned to one of three groups. Group A will be informed their drinking will be assessed at baseline and again in one month (as in a cohort study design). Group B will be told the study is an intervention trial and they are in the control group. Group C will be told the study is an intervention trial and they are in the intervention group. All will receive exactly the same brief educational material to read. After one month, alcohol intake for the past 4 weeks will be assessed. Discussion: The experimental manipulations address subtle and previously unexplored ways in which participant behaviour may be unwittingly influenced by standard practice in trials. Given the necessity of relying on self-reported outcome, it will not be possible to distinguish true behaviour change from reporting artefact. This does not matter in the present study, as any effects of awareness of study design or allocation involve bias that is not well understood. There has been little research on awareness effects, and our outcomes will provide an indication of the possible value of further studies of this type and inform hypothesis generation

Serum triiodothyronine levels and inflammatory cytokine production capacity

Increasing evidence suggests that pro-inflammatory cytokines are at play in lowering peripheral thyroid hormone levels during critical illness. Conversely, thyroid hormones have been suggested to enhance production of inflammatory cytokines. In view of these considerations, we hypothesized a mutual association between triiodothyronine and pro-inflammatory cytokines. Therefore we evaluated the relation between both circulating and induced inflammatory markers and serum thyroid function parameters in the Leiden 85-plus Study. We found that higher circulating levels of inflammatory markers were associated with lower levels of free serum triiodothyronine. In turn, higher serum free triiodothyronine levels were related to higher production capacity of pro-inflammatory cytokines after stimulation with lipopolysaccharide. By combining in vivo and ex vivo data, we were able to demonstrate for the first time the existence of a potential feedback mechanism between thyroid function and immune production capacity. We conclude that maintenance of normal thyroid function might be important for a preserved immune response in elderly human populations