Age and Attentional Capacity

Accident and fatality rates begin to increase after age 55. Previous research indicated only weak relationships between crash involvement and poor acuity. The other factor that may influence driving performance is impaired attentional function. Green and Bavelier (2003) showed that action-video-game players have greater attention capacity than non-video-game players. More important, non-video-game players can be trained to enhance the capacity of visual attention and its spatial distribution. In that study, all participants were young adults (aged from 18 to 23). It is not clear whether the reduced driving capability of older adults is due to a decreased attention capacity. In this paper, attention capacity of young and older drivers was examined using a flanker task paradigm. Participants were asked to respond to two shapes (diamond/square) in one of six circles arranged in a ring. At the same time, a distractor (a square/a diamond) was displayed on the left or the right of the ring. The workload of the task was manipulated by presenting different shapes in all the other circles or only one shape was present in the ring. The influence of the irrelevant shape on the performance (flanker effect) under different load conditions was compared between older and younger drivers. Consistent with previous research, the reaction time under the high-load condition was longer than in the low-load condition and older drivers’ reaction time was slower than younger drivers’. However, for both age groups, flanker effect only existed for the low-load condition and tends to disappear in the high-load condition

Performance on Cue Recognition and Evasive Action Skills as Predictors of Effective Driving in College-Age Drivers

Two experiments compared self-reported driving effectiveness oflicensed drivers (mean age 19 years) to their performance on two simulateddriving tasks. For both experiments, drivers first completed a driving historyquestionnaire. In Experiment 1, they then performed Cue Recognition, whichuses stationary line drawings of vehicles as stimuli and requires a turning orbraking response to an appropriate stimulus. Males responded faster than females,especially for the most complex choice responses, and reported more tickets.Drivers reporting no tickets responded slower than those reporting at least oneticket, and they reported fewer accidents. In Experiment 2, drivers also performedEvasive Action Skills, which uses more realistic recorded driving scenarios inwhich the appearance of a hazard is the imperative stimulus that commands theappropriate turn or brake response. Number of errors on Evasive Action Skillscorrelated significantly with number of self-reported accidents. Response timeson Cue Recognition and Evasive Action Skills were correlated, but there was norelation between response times on Cue Recognition and errors on EvasiveAction Skills. However, a comparison of the 10 fastest and 10 slowest drivers onCue Recognition showed that the fastest responders committed significantly moreerrors on Evasive Action Skills than did the slowest responders. The data in bothexperiments reflect a speed-accuracy tradeoff

Stimulus-Response Compatibilitiy Effects for Warning Signals and Steering Responses

Stimulus-response compatibility is relevant to the way a collision avoidance system signals a hazard. Using the location of a warning tone as the signal, standard spatial compatibility effects predict that it would be most beneficial to have the tone correspond to the desired response direction. However, because drivers typically turn away from sounds created by hazards, they may adopt a frame of reference where turning away from the warning tone is more compatible than responding toward it. This issue was examined in an experiment in which subjects responded to tones in the left or right ear by turning a steering wheel clockwise or counterclockwise, with the meaning of the tones manipulated to simulate warning signals. Two groups received typical compatibility instructions (tone instructions), and two received instructions specifying that the tone was a warning signal (warning instructions) indicating either the location of the danger (from which they were to turn away) or the escape direction (toward which they were to turn). The compatibility effect was in the same direction and of the same magnitude for both the warning instructions and the tone instructions. This outcome implies that instructions to turn away from danger did not cause subjects to adopt an avoidance frame of reference and that spatial correspondence was the overriding factor. The results suggest that collision avoidance systems should signal the escape direction, but these results need to be verified in simulated and actual driving conditions

Effect of Listening to Music as a Function of Driving Complexity: A Simulator Study on the Differing Effects of Music on Different Driving Tasks

Research in regards to music’s effects on driving performance has been mixed. Previous research has found that music adds to mental workload. Other research has found that high mental workload is related to poorer driving performance in simulation. In this study, mental workload was manipulated by varying visual complexity and type of task (i.e., car-following or braking for unexpected obstacles). It was found that steering variance and delay in carfollowing response were reduced by music under low-workload conditions, while number of collisions with cars and number of lane excursions were increased under high-workload conditions. A practice effect was also found, with participants performing better when listening to music with more practice

Effect of a Side Collision-Avoidance Signal on Simulated Driving with a Navigation System

Effects of a side collision-avoidance system (SCAS) signal on driving behavior were examined in an environment in which a nagivation signal was also used. Sixteen undergraduate students participated in this study, and a computerbased STISIM driving simulator was used in the project. Subjects were asked to respond to two signals, a visually displayed directional signal generated by a simulated navigation system (NAS) and a monaural auditory tone from a simulated SCAS presented after a NAS signal. Subjects were instructed that the SCAS signal conveyed directional information about an impending threat (the location of the danger from which they were to turn, or the escape direction toward which they were to turn). Contrary to previous findings in a non-driving environment (Wang et al., 2003), response time (RT) was significantly shorter for the group in which the location of the SCAS signal was spatially compatible with the location of the danger than for the group in which the SCAS signal location was incompatible with the location of the danger. Mean RT was not significantly shorter when the direction of the NAS signal and the location of the SCAS signal corresponded than when they did not. Given that subjects tended to withhold responding until they perceived the encroaching car, the benefit of a SCAS may be to direct a driver’s attention in the direction of an impending threat before the driver would ordinarily detect it

Perinatal paracetamol exposure in mice does not affect the development of allergic airways disease in early life

Background Current data concerning maternal paracetamol intake during pregnancy, or intake during infancy and risk of wheezing or asthma in childhood is inconclusive based on epidemiological studies. We have investigated whether there is a causal link between maternal paracetamol intake during pregnancy and lactation and the development of house dust mite (HDM) induced allergic airways disease (AAD) in offspring using a neonatal mouse model. Methods Pregnant mice were administered paracetamol or saline by oral gavage from the day of mating throughout pregnancy and/or lactation. Subsequently, their pups were exposed to intranasal HDM or saline from day 3 of life for up to 6 weeks. Assessments of airway hyper-responsiveness, inflammation and remodelling were made at weaning (3 weeks) and 6 weeks of age. Results Maternal paracetamol exposure either during pregnancy and/or lactation did not affect development of AAD in offspring at weaning or at 6 weeks. There were no effects of maternal paracetamol at any time point on airway remodelling or IgE levels. Conclusions Maternal paracetamol did not enhance HDM induced AAD in offspring. Our mechanistic data do not support the hypothesis that prenatal paracetamol exposure increases the risk of childhood asthma

Plasma Zonulin Levels in Childhood Nephrotic Syndrome

Objective: We conducted this study to test the hypothesis that plasma zonulin levels are elevated in pediatric patients with nephrotic syndrome compared to healthy controls.Study Design: Plasma zonulin levels were measured by ELISA in 114 children enrolled in the NEPTUNE study. Clinical and laboratory data were retrieved from the NEPTUNE database.Results: The median age of the patients was 10 (IQR = 5 to 14) years, 59 were male, 64 had minimal change disease, 47 focal segmental glomerulosclerosis, median eGFR was 96 (IQR = 80 to 114) ml/min/1.73 m2, and median urine protein:creatinine ratio was 0.5 (IQR = 0.1 to 3.4) (g:g). The plasma zonulin level was 14.2 ± 5.0 vs. 10.2 ± 2.5 ng/ml in healthy adults in a report using the same assay kit, P = 0.0025. These findings were confirmed in an independent cohort of children with nephrotic syndrome compared to healthy age-matched controls, P = 0.01. Zonulin concentrations did not differ in children with minimal change disease vs. focal segmental glomerulosclerosis, frequently relapsing vs. steroid-dependent vs. steroid-resistant clinical course, and were not influenced by the immunosuppressive treatment regimen. There was no relationship between plasma zonulin levels and the absolute or percentage change in proteinuria from enrollment until the time of the zonulin assay.Conclusion: Plasma zonulin levels are elevated in childhood nephrotic syndrome regardless of level of proteinuria or specific treatment. The cause of the high plasma zonulin levels and whether zonulin contributes to glomerular injury requires further study

Challenges in quantifying changes in the global water cycle

Human influences have likely already impacted the large-scale water cycle but natural variability and observational uncertainty are substantial. It is essential to maintain and improve observational capabilities to better characterize changes. Understanding observed changes to the global water cycle is key to predicting future climate changes and their impacts. While many datasets document crucial variables such as precipitation, ocean salinity, runoff, and humidity, most are uncertain for determining long-term changes. In situ networks provide long time-series over land but are sparse in many regions, particularly the tropics. Satellite and reanalysis datasets provide global coverage, but their long-term stability is lacking. However, comparisons of changes among related variables can give insights into the robustness of observed changes. For example, ocean salinity, interpreted with an understanding of ocean processes, can help cross-validate precipitation. Observational evidence for human influences on the water cycle is emerging, but uncertainties resulting from internal variability and observational errors are too large to determine whether the observed and simulated changes are consistent. Improvements to the in situ and satellite observing networks that monitor the changing water cycle are required, yet continued data coverage is threatened by funding reductions. Uncertainty both in the role of anthropogenic aerosols, and due to large climate variability presently limits confidence in attribution of observed changes

Extracellular loops 2 and 3 of the calcitonin receptor selectively modify agonist binding and efficacy.

Class B peptide hormone GPCRs are targets for the treatment of major chronic disease. Peptide ligands of these receptors display biased agonism and this may provide future therapeutic advantage. Recent active structures of the calcitonin (CT) and glucagon-like peptide-1 (GLP-1) receptors reveal distinct engagement of peptides with extracellular loops (ECLs) 2 and 3, and mutagenesis of the GLP-1R has implicated these loops in dynamics of receptor activation. In the current study, we have mutated ECLs 2 and 3 of the human CT receptor (CTR), to interrogate receptor expression, peptide affinity and efficacy. Integration of these data with insights from the CTR and GLP-1R active structures, revealed marked diversity in mechanisms of peptide engagement and receptor activation between the CTR and GLP-1R. While the CTR ECL2 played a key role in conformational propagation linked to Gs/cAMP signalling this was mechanistically distinct from that of GLP-1R ECL2. Moreover, ECL3 was a hotspot for distinct ligand- and pathway- specific effects, and this has implications for the future design of biased agonists of class B GPCRs

Revisiting the Effect of Acute P. falciparum Malaria on Epstein-Barr Virus: Host Balance in the Setting of Reduced Malaria Endemicity

Burkitt's lymphoma (BL), an EBV-associated tumour, occurs at high incidence in populations where malaria is holoendemic. Previous studies in one such population suggested that acute P.falciparum infection impairs EBV-specific T-cell surveillance, allowing expansion of EBV infected B-cells from which BL derives. We re-examined the situation in the same area, The Gambia, after a reduction in malaria endemicity. Cellular immune responses to EBV were measured in children with uncomplicated malaria before (day 0) and after treatment (day 28), comparing EBV genome loads in blood and EBV-specific CD8+ T-cell numbers (assayed by MHC Class I tetramers and IFNγ ELISPOTS) with those seen in age- and sex-matched healthy controls. No significant changes were seen in EBV genome loads, percentage of EBV-specific CD8+ T-cells and IFNγ producing T-cells in acute versus convalescent samples, nor any difference versus controls. Regression assays performed also no longer detected any impairment of EBV-specific T-cell surveillance. Acute uncomplicated malaria infection no longer alters EBV-specific immune responses in children in The Gambia. Given the recent decline in malaria incidence in that country, we hypothesise that gross disturbance of the EBV-host balance may be a specific effect of acute malaria only in children with a history of chronic/recurrent malaria challenge