29 research outputs found

    Age and Attentional Capacity

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    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

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    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

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    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

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    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

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    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

    Identification of PLCL1 Gene for Hip Bone Size Variation in Females in a Genome-Wide Association Study

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    Osteoporosis, the most prevalent metabolic bone disease among older people, increases risk for low trauma hip fractures (HF) that are associated with high morbidity and mortality. Hip bone size (BS) has been identified as one of the key measurable risk factors for HF. Although hip BS is highly genetically determined, genetic factors underlying the trait are still poorly defined. Here, we performed the first genome-wide association study (GWAS) of hip BS interrogating ∼380,000 SNPs on the Affymetrix platform in 1,000 homogeneous unrelated Caucasian subjects, including 501 females and 499 males. We identified a gene, PLCL1 (phospholipase c-like 1), that had four SNPs associated with hip BS at, or approaching, a genome-wide significance level in our female subjects; the most significant SNP, rs7595412, achieved a p value of 3.72×10−7. The gene's importance to hip BS was replicated using the Illumina genotyping platform in an independent UK cohort containing 1,216 Caucasian females. Two SNPs of the PLCL1 gene, rs892515 and rs9789480, surrounded by the four SNPs identified in our GWAS, achieved p values of 8.62×10−3 and 2.44×10−3, respectively, for association with hip BS. Imputation analyses on our GWAS and the UK samples further confirmed the replication signals; eight SNPs of the gene achieved combined imputed p values<10−5 in the two samples. The PLCL1 gene's relevance to HF was also observed in a Chinese sample containing 403 females, including 266 with HF and 177 control subjects. A SNP of the PLCL1 gene, rs3771362 that is only ∼0.6 kb apart from the most significant SNP detected in our GWAS (rs7595412), achieved a p value of 7.66×10−3 (odds ratio = 0.26) for association with HF. Additional biological support for the role of PLCL1 in BS comes from previous demonstrations that the PLCL1 protein inhibits IP3 (inositol 1,4,5-trisphosphate)-mediated calcium signaling, an important pathway regulating mechanical sensing of bone cells. Our findings suggest that PLCL1 is a novel gene associated with variation in hip BS, and provide new insights into the pathogenesis of HF

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    New genetic loci link adipose and insulin biology to body fat distribution.

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    Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

    Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

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    BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to &lt;90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], &gt;300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of &lt;15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P&lt;0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P&lt;0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
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