It is premature to test older drivers with the SIMARD-MD

Background

A new tool, the SIMARD-MD, has been proposed to help physicians identify cognitively impaired drivers who may be unfit to drive, but little empirical evidence is available to justify its use. We analyzed data from a cohort of older Canadian drivers who had undergone cognitive testing to: (1) correlate the SIMARD-MD with other tools that measure cognition (e.g., trail-making test), (2) identify how many drivers, using published cut-offs on the SIMARD-MD, would be recommended to lose their license, or be considered fit to drive, or be required to undergo further driving assessment, and (3) determine if the SIMARD-MD is biased by level of education as many cognitive tools are.

Methods

Cross-sectional data from 841 drivers aged 70 and over from seven Canadian sites who are enrolled in a 5-year cohort study were used for the analyses. Scores on the SIMARD-MD were correlated with scores on the other cognitive measures. The recommendations that would be made based on the SIMARD-MD scores were based on published cut-off values suggested by the authors of the tool. The impact of education status was examined using linear regression controlling for age.

Results

Correlations between the SIMARD-MD and other cognitive measures ranged from .15 to .86. Using published cut-off scores, 21 participants (2.5%) would have been recommended to relinquish their licenses, 428 (50.9%) would have been deemed fit to drive, and 392 (46.6%) would have been required to undergo further testing. We found a difference of 8.19 points (95% CI = 4.99, 11.40, p < .001) in favor of drivers with post-secondary education versus those without, representing over 11% of the mean score.

Discussion

The SIMARD-MD is unlikely to be valuable to clinicians because it lacks sufficient precision to provide clear recommendations about fitness-to-drive. Recommendations based solely on the SIMARD-MD may place many seniors at risk of losing their transportation mobility or incurring unnecessary stress and costs to prove they are safe to drive. Furthermore, the education bias may create an unwanted structural inequity. Hence, adoption of the SIMARD-MD as a tool to determine fitness-to-drive appears premature.     

Two-dimensional elastoplasticity: Approximation by mixed finite elements

Two-dimensional elastoplastic problems are used to assess the performance of a family of mixed finite elements in the non-linear regime. In particular, four-node bilinear quadrilateral elements that exhibit high accuracy in coarse meshes are used to simulate plane stress, plane strain, axisymmetric and (shear-deformable) plate bending problems. The excellent performance of these elements is demonstrated with a number of discriminating examples selected from the literature. In addition, agreement is observed in the limit load predicted by the axisymmetric solid and plate bending elements.     

Radical functions in vivo: a critical review of current concepts and hypotheses

Most of the basic knowledge about radical reactions comes from radiation chemical studies in vitro. In view of the rapidly increasing knowledge on radical reaction in vivo, it is important to reconcile the fundamental physico-chemical reaction characteristics of radicals with the need to explain their alleged biological effects. Severe problems in the understanding of their in vivo action remain unsolved. An example is phagocytosis, which seems to be a paradigm of a 'deleterious' radical process. The exact mechanism is not clear; so it is an open question whether the intruder is eventually killed by radicals (like OH) or by endproducts of radical reactions (like H2O2 and/or HOCl). It is even more difficult to understand signalling by radicals: owing to their chemical nature they are 'unspecifically' reacting species--they withdraw or add electrons--and thus their reactions are governed by redox-properties. Since all radicals have different redox characteristics and different molecular shapes, the usual key-and-keyhole picture for molecular interaction does not apply, as there, is no reactive site conceivable which has the property of reacting with radicals 'specifically. Our intent in this article is: (i) to briefly review some fundamental characteristics of in vitro radical reactions, (ii) to extrapolate from this to the conditions in vivo, and (iii) to discuss current hypotheses concerning the redox-regulation of cellular signalling. This leads us to the tentative conclusion that radicals per se must be tolerated by the cell and do not threaten its life, if they stay below a certain concentration limit. The main biological implication of radical-reactions seems to be that the cell derives signals from the balance of oxidative versus reductive processes and that radicals may interact with pathways of intra- and intercellular communication.     

Prediction by means of endogenous and exogenous evoked potentials of the favorable evolution of a prolonged coma

A neurophysiological follow-up (EEG, exogenous and endogenous evoked potentials--EP) was performed over a 4-month period in a patient who presented a long-lasting coma following a cardiac arrest and an amniotic embolism. A pure anoxic aetiology was ruled out starting from the second day on the basis of a dissociation between mildly altered flash visual EP and markedly altered somatosensory EP, indicating focal brain-stem pathology. Endogenous EP reappeared after 12 days. This patient recovered consciousness after 51 days. Despite the absence of MRI abnormalities, we put forward the hypothesis that a brain-stem embolism had, in fact, worsened the clinical picture of an actually moderate anoxia. This case exemplifies the interest of an integrated neurophysiological approach (EEG, exogenous three-modality EP and endogenous EP) in the early evaluation of coma. It also illustrates the complement between structural imaging and functional assessment of the nervous system.     

The oxygen defect perovskite BaLa4Cu5O13.4, a metallic conductor

A new oxygen defect perovskite BaLa₄Cu₅O_13.4, characterized by a mixed valence of copper has been isolated; the parameters of the tetragonal cell are closely related to that of the cubic perovskite:a = 8.644(4)$\text{A}\text{?}\text{=}\text{a}{}_{\mathrm{p}}\text{5√}$ and c = 3.867(3) $\text{A}\text{?}\text{=}\text{a}{}_{\mathrm{p}}$. The X-ray diffraction study shows that the atoms are displaced from their ideal positions in the cubic cell, owing to the presence of ordered oxygen vacancies. The study of conductivity, magnetic susceptibility and thermoelectric power versus temperature shows that this oxide is a very good metallic conductor.     

Long-term functional outcome following transient middle cerebral artery occlusion in the rat: Correlation between brain damage and behavioral impairment.

The assessment of both histological and functional long-term outcomes after cerebral ischemia is increasingly recommended for preclinical studies. Whereas correlations between behavioral impairments and primary ischemic lesion are documented, little is known about their relationships with remote nonischemic regions that undergo secondary degeneration, such as the thalamus. Anesthetized rats were subjected to mild (30 min) or severe (60 min) occlusion of the middle cerebral artery. Two months after ischemia, sensorimotor behavior was assessed according to the neurological score, limb-placing, adhesive-removal, and staircase tests; the final histological lesion was measured after this assessment. Cortical damage was correlated to all transient and long-lasting sensorimotor deficits, whereas striatal lesion was more consistently reflected by the forelimb-placing reflexes and adhesive-removal motor deficits. By contrast, the thalamic atrophy was not correlated to early neurological impairment, but rather to the late sensory deficit at the adhesive-removal test and to the skilled forepaw reaching alteration at the staircase test. This suggests that thalamus contributes, albeit moderately, to the ischemia-induced long-lasting sensorimotor deficits, some of which represent relevant targets for therapeutic interventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prognostic factors in advanced stage non-small cell bronchial cancer: experiences of the European Lung Cancer Working Party

The European Lung Cancer Working Party has investigated prognostic factors for response, overall survival, long term survival in a population with advanced non small cell lung cancer registered in a clinical trial evaluating platinum derivatives-containing chemotherapy regimens. Various factors have been identified in multivariate analyses and were classified using RECPAM methodology. In addition to the clinical factors such as disease extent and performance status were shown, as significant predictors, rarely studied biological factors like pretherapeutic leucocyte and polynuclear levels. The obtention of an objective response to chemotherapy appeared to be a major prognostic factor for further survival.     

VIRCON: Interactive System for Teaching Construction Management

The focus in this paper is on a system, developed by the writers, called VIRCON (short for VIRtual CONstruction), in which the traditional construction planning is combined with 3D∕4D models of the project. To facilitate current best practices with 3D∕4D models of the project, VIRCON has been implemented using object-oriented programming, client/server configuration, database management information, and CAD systems. The real innovation in the design of VIRCON is associated with the unique scheduling and simulation engine developed to integrate cost planning and scheduling and accommodate integrated cross-impact analysis. VIRCON has been validated by means of student group projects on a course where many of the project management techniques are being taught. The teaching approach conducted with the utilization of VIRCON has shown the way forward in creating a dynamic and interactive learning atmosphere. This paper also outlines the experience gained from teaching construction planning fundamentals by means of the VIRCON system.