Evaluation of 2 cognitive abilities tests in a dual-task environment

Most real world operators are required to perform multiple tasks simultaneously. In some cases, such as flying a high performance aircraft or trouble shooting a failing nuclear power plant, the operator's ability to time share or process in parallel" can be driven to extremes. This has created interest in selection tests of cognitive abilities. Two tests that have been suggested are the Dichotic Listening Task and the Cognitive Failures Questionnaire. Correlations between these test results and time sharing performance were obtained and the validity of these tests were examined. The primary task was a tracking task with dynamically varying bandwidth. This was performed either alone or concurrently with either another tracking task or a spatial transformation task. The results were: (1) An unexpected negative correlation was detected between the two tests; (2) The lack of correlation between either test and task performance made the predictive utility of the tests scores appear questionable; (3) Pilots made more errors on the Dichotic Listening Task than college students

The effects of stimulus modality and task integrality: Predicting dual-task performance and workload from single-task levels

The influence of stimulus modality and task difficulty on workload and performance was investigated. The goal was to quantify the cost (in terms of response time and experienced workload) incurred when essentially serial task components shared common elements (e.g., the response to one initiated the other) which could be accomplished in parallel. The experimental tasks were based on the Fittsberg paradigm; the solution to a SternBERG-type memory task determines which of two identical FITTS targets are acquired. Previous research suggested that such functionally integrated dual tasks are performed with substantially less workload and faster response times than would be predicted by suming single-task components when both are presented in the same stimulus modality (visual). The physical integration of task elements was varied (although their functional relationship remained the same) to determine whether dual-task facilitation would persist if task components were presented in different sensory modalities. Again, it was found that the cost of performing the two-stage task was considerably less than the sum of component single-task levels when both were presented visually. Less facilitation was found when task elements were presented in different sensory modalities. These results suggest the importance of distinguishing between concurrent tasks that complete for limited resources from those that beneficially share common resources when selecting the stimulus modalities for information displays

Prótese Nasal Para Uso Noturno

O Autor, neste trabalho, salienta os problemas inerentes à confecção de uma prótese facial, destacando aqueles referentes ao seu uso durante o período "noturno". Propõe método de confecção de prótese nasal de recobrimento em PVC resiliente, utilizando aparelho Omnivac IV, usado em prótese dental na construção de vários aparelhos. Após a descrição do método, conclui que este ofereceu uma série de vantagens. Os portadores destas próteses mostraram-se satisfeitos, e sob o ponto de vista do autor o único inconveniente é ser o material incolor

Current socio-economic measures, and not those measured during infancy, affect bone mass in poor urban South african children.

Understanding the impact of socio-economic status (SES) on physical development in children is important, especially in developing countries where considerable inequalities persist. This is the first study to examine the association between SES on bone development at the whole body, femoral neck, and lumbar spine in black children living in Soweto and Johannesburg, South Africa. Linear regression models were used to study associations between SES during infancy and current SES, anthropometric, and DXA-derived bone mass in 9/10-yr-old children (n = 309). Findings suggest that current SES measures, rather than SES during infancy, are stronger predictors of current whole body bone area (BA) and whole body BMC after adjusting for body size, pubertal development, physical activity, habitual dietary calcium intake, and body composition. SES had no significant effect on either hip or spine bone mass. Caregiver's marital/cohabiting status (indicator of social support) and whether there was a television in the home (indicator of greater income) at age 9/10 yr were the most important socio-economic determinants of whole body BA and BMC. SES has a significant independent effect on whole body BMC through its impact on BA. This suggests that poverty alleviation policies in South Africa could have a positive effect on bone health

On the Mental Workload Assessment of Uplift Mapping Representations in Linked Data

Self-reporting procedures have been largely employed in literature to measure the mental workload experienced by users when executing a specific task. This research proposes the adoption of these mental workload assessment techniques to the task of creating uplift mappings in Linked Data. A user study has been performed to compare the mental workload of “manually” creating such mappings, using a formal mapping language and a text editor, to the use of a visual representation, based on the block metaphor, that generate these mappings. Two subjective mental workload instruments, namely the NASA Task Load Index and the Workload Profile, were applied in this study. Preliminary results show the reliability of these instruments in measuring the perceived mental workload for the task of creating uplift mappings. Results also indicate that participants using the visual representation achieved smaller and more consistent scores of mental workload

Hazard prediction discriminates between novice and experienced drivers

Typical hazard perception tests often confound multiple processes in their responses. The current study tested hazard prediction in isolation to assess whether this component can discriminate between novice and experienced drivers. A variant of the hazard perception test, based on the Situation Awareness Global Assessment Technique, found experienced drivers to outperform novices across three experiments suggesting that the act of predicting an imminent hazard is a crucial part of the hazard-perception process. Furthermore three additional hypotheses were tested in these experiments. First, performance was compared across clips of different length. There was marginal evidence that novice drivers' performance suffered with the longest clips, but experienced drivers’ performance did not, suggesting that experienced drivers find hazard prediction less effortful. Secondly, predictive accuracy was found to be dependent on the temporal proximity of visual precursors to the hazard. Thirdly the relationship between the hazard and its precursor was found to be important, with less obvious precursors improving the discrimination between novice and experience drivers. These findings demonstrate that a measure of hazard prediction, which is less confounded by the influence of risk appraisal than simple response time measures, can still discriminate between novice and experienced drivers. Application of this methodology under different conditions can produce insights into the underlying processes that may be at work, whilst also providing an alternative test of driver skill in relation to the detection of hazards

A Multilevel Approach to Relating Subjective Workload to Performance After Shifts in Task Demand

Objective: The aim of this laboratory experiment was to demonstrate how taking a longitudinal, multilevel approach can be used to examine the dynamic relationship between subjective workload and performance over a given period of activity involving shifts in task demand.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Extended conformations of polypeptides and proteins in urea and guanidine hydrochloride

By analyzing the effect of urea and guanidine hydrochloride on the circular dichroism of many polypeptides and proteins, it is concluded that under conditions of high concentration of the perturbant and at low temperatures the resultant state approached is that of a local extended helix structure instead of a completely random coil. Intensification by urea and guanidine hydrochloride of the circular dichroism bands of poly- L -proline II leads to the proof that the mechanism of interaction of urea and guanidine hydrochloride with proteins is through hydrogen bonding to the backbone carbonyl group.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37834/1/360120310_ftp.pd