1,326 research outputs found

    The Influence of Passenger-Driver Interaction on Young Drivers

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    The mechanisms for young drivers being at increased risk of collision with peer aged passengers in the car are not well understood. Most studies infer a link between passenger distraction and the number of passengers, but a causal link has not been previously shown. A group of young drivers with their full Ontario, Canada G license were tested in a simulated driving environment in three conditions. The first condition involved a peer aged female passenger who asked the driver questions as they navigated a course. The second condition involved the same passenger sitting silently in the passenger seat while the driver navigated a course. The third condition involved the passenger being absent, and the driver was alone in the car while they navigated a course. Speed and way finding behaviours were found to deteriorate in the first condition compared to the other two, and standard deviation of lane position and reaction times were found to improve in the first condition compared to the other two, indicating that the drivers were moving their eyes around the environment less with conversation. This highlights the importance of reducing passenger distractions for younger drivers

    The Influence of Passengers on Driving in Young Drivers with Varying Levels of Experience

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    Young drivers are at disproportionate risk of collision. It is unclear whether it is age or lack of driving experience that is the problem because age and experience are confounded in most studies (experienced drivers are typically much older). This study focused on drivers who were about the same age: all within the critical first years of skill development. We compared drivers just starting to drive (learner’s license) with those with a full license. Young drivers are especially at risk when driving with passengers. Consequently, we were interested in how the ability to drive with passengers changes in these first years. Driving performance was measured in a driving simulator when the passenger was absent (Absent condition), and when there was a passenger who was either asking the driver questions or was silent (Talking and Silent conditions). As predicted, the experienced young drivers had lower hazard response times and fewer collisions. Similarly, as predicted, performance was worse in the Talking condition, insofar as more drivers missed their turnoff in the way-finding task (where they were required to arrive at a certain destination using signs and landmarks). However, there were also interactive effects of experience and condition. In-vehicle conversation had an especially negative effect on the least experienced drivers, producing more collisions. Conversely, the more experienced young drivers sped up when they were driving with a passenger who talked with them. There was little difference between Silent and Absent conditions for all measures. This suggests in-vehicle conversation may be the critical factor

    Definition of spacecraft standard interfaces by the NASA Space Assembly and Servicing Working Group (SASWG)

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    The purpose of the NASA Space Assembly and Servicing Working Group (SASWG) is to study enabling technologies for on-orbit spacecraft maintenance and servicing. One key technology required for effective space logistics activity is the development of standard spacecraft interfaces, including the 'Basic Set' defined by NASA, the U.S. Space Command, and industry panelists to be the following: (1) navigation aids; (2) grasping, berthing, and docking; and (3) utility connections for power, data, and fluids. Draft standards have been prepared and referred to professional standards organizations, including the AIAA, EIA, and SAE space standards committee. The objective of the SASWG is to support these committees with the technical expertise required to prepare standards, guidelines, and recommended practices which will be accepted by the ANSI and international standards organizations, including the ISO, IEC, and PASC

    Impaired Endothelial Function in Coronary Heart Disease Patients With Depressive Symptomatology

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    OBJECTIVES The purpose of this study was to assess whether depressive symptomatology was associated with vascular endothelial dysfunction in patients with coronary heart disease (CHD). BACKGROUND In patients with CHD, the presence of depression is associated with a two to four times increased risk of mortality, but the disease pathways involved are uncertain. Endothelial dysfunction is an established risk factor for cardiovascular events in patients with CHD. METHODS Flow-mediated dilation (FMD) of the brachial artery, a measure of endothelial function, was assessed in 143 patients (99 men, 44 women), ages 40 to 84 years (mean age, 63 ± 10 years), with documented CHD. RESULTS Patients with significant depressive symptomatology, as indicated by a Beck Depression Inventory (BDI) score ≥10 (n = 47) showed attenuated FMD (p = 0.001) compared with patients that were not depressed (BDI <10 n = 96). The use of antidepressant medication was associated with improved FMD (p < 0.05). CONCLUSIONS The increased risk of cardiovascular events in CHD patients with elevated symptoms of depression may be mediated, in part, by endothelial dysfunction

    Correlation harvesting between particle detectors in uniform motion

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    We investigate the correlation harvesting protocol using two Unruh-DeWitt particle detectors moving along four classes of uniformly accelerated trajectories categorized by Letaw: linear, catenary, cusped, and circular motions. For each trajectory, two types of configurations are carried out: one possesses a stationary (time-translation invariant) Wightman function and the other is nonstationary. We find that detectors undergoing linear, catenary, and cusped motions gain fewer correlations in the nonstationary configurations compared to those in stationary configurations. Detectors in circular motion have similar behavior in both configurations. We discuss the relative suppression of correlation harvesting due to high acceleration for each case. Remarkably we find that under certain circumstances detectors in both linear and circular states of motion can harvest genuine (non-communication assisted) entanglement even though they are in causal contact.Comment: 16 pages, 7 figure

    The contribution of evolutionarily volatile promoters to molecular phenotypes and human trait variation

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    BACKGROUND: Promoters are sites of transcription initiation that harbour a high concentration of phenotype-associated genetic variation. The evolutionary gain and loss of promoters between species (collectively, termed turnover) is pervasive across mammalian genomes and may play a prominent role in driving human phenotypic diversity. RESULTS: We classified human promoters by their evolutionary history during the divergence of mouse and human lineages from a common ancestor. This defined conserved, human-inserted and mouse-deleted promoters, and a class of functional-turnover promoters that align between species but are only active in humans. We show that promoters of all evolutionary categories are hotspots for substitution and often, insertion mutations. Loci with a history of insertion and deletion continue that mode of evolution within contemporary humans. The presence of an evolutionary volatile promoter within a gene is associated with increased expression variance between individuals, but only in the case of human-inserted and mouse-deleted promoters does that correspond to an enrichment of promoter-proximal genetic effects. Despite the enrichment of these molecular quantitative trait loci (QTL) at evolutionarily volatile promoters, this does not translate into a corresponding enrichment of phenotypic traits mapping to these loci. CONCLUSIONS: Promoter turnover is pervasive in the human genome, and these promoters are rich in molecularly quantifiable but phenotypically inconsequential variation in gene expression. However, since evolutionarily volatile promoters show evidence of selection, coupled with high mutation rates and enrichment of QTLs, this implicates them as a source of evolutionary innovation and phenotypic variation, albeit with a high background of selectively neutral expression variation. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13059-022-02634-w

    Performance of a novel system for high-resolution tracking of marine fish societies

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    Recent advances in tracking systems have revolutionized our ability to study animal movement in the wild. In aquatic environments, high-resolution acoustic telemetry systems make it technically possible to simultaneously monitor large amounts of individuals at unprecedented spatial and temporal resolutions, providing a unique opportunity to study the behaviour and social interactions using a reality mining approach. Despite the potential, high-resolution telemetry systems have had very limited use in coastal marine areas due to the limitations that these environments pose to the transmission of acoustic signals. This study aims at designing and testing a high-resolution acoustic telemetry system to monitor, for the first time, a natural fish population in an open marine area. First, we conducted preliminary range tests and a computer simulation study to identify the optimal design of the telemetry system. Then, we performed a series of stationary and moving tests to characterize the performance of the system in terms of positioning efficiency and precision. Finally, we obtained a dataset corresponding to the movements of 170 concurrently tagged individuals to demonstrate the overall functioning of the system with a real study case of the behaviour of a small-bodied coastal species. Our results show that high-resolution acoustic telemetry systems efficiently generate positional data in marine systems, providing a precision of few meters, a temporal resolution of few seconds, and the possibility of tracking hundreds of individuals simultaneously. Data post-processing using a trajectory filter and movement models proved to be key to achieve a sub-meter positioning precision. The main limitation detected for our system was the restricted detection range, which was negatively affected by the stratification of the water column. Our work demonstrates that high-resolution acoustic telemetry systems are an effective method to monitor the movements of free-ranging individuals at the population level in coastal sites. By providing highly precise positioning estimates of large amounts of individuals, these systems represent a powerful tool to study key ecological processes regarding the social interactions of individuals, including social dynamics, collective movements, or responses to environmental perturbations, and to extend the studies to poorly studied small-sized species or life-stages.The telemetry system was financed by the German Federal Ministry of Education and Research (grant no. #033W024A). EA was supported by a Margalida Comas postdoctoral grant from the Government of the Balearic Islands and the European Social Fund (Grant No. PD/023/2018). JA was supported by a Ramon y Cajal Grant (Grant No. RYC2018-024488-I) and received funding from the CLOCKS R&D Project (Grant No. PID2019-104940GA-I00) and the intramural research project JSATS (Grant No. PIE 202030E002) funded by the Spanish Ministry of Science and Innovation and the Spanish National Research Council. GFB was supported by a Ph.D. fellowship (FPI-INIA 2015–0013-CPD2015-0084) from the National Institute for Agricultural and Food Research and Technology.Peer reviewe

    Heightened inflammasome activation is linked to age-related cognitive impairment in Fischer 344 rats

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    <p>Abstract</p> <p>Background</p> <p>Members of the mammalian nucleotide binding domain, leucine-rich repeat (LRR)-containing receptor (NLR) family of proteins are key modulators of innate immunity regulating inflammation. Our previous work has shown that among the members of this family, NLRP1/NALP1, present in neurons, plays a crucial role in inflammasome formation and the production of the inflammatory cytokines interleukin (IL) -1β and IL-18 after various types of central nervous system injury.</p> <p>Results</p> <p>We investigated whether age-related cognitive decline may involve a heightened inflammatory response associated with activation of the NLRP1 inflammasome in the hippocampus. Young (3 months) and aged (18 months) male Fischer 344 rats were tested in a spatial acquisition task via Morris water maze. Following behavioral testing, hippocampal lysates were assayed for expression of NLRP1 inflammasome components and inflammatory cytokines. Hippocampal lysates from aged rats showed significantly higher levels of NLRP1 inflammasome constituents, caspase-1, caspase-11, the purinergic receptor P2X7, pannexin-1 and X-linked inhibitor of apoptosis (XIAP) than lysates from younger animals. Following treatment with probenecid, an inhibitor or pannexin-1, aged animals demonstrated reduction in inflammasome activation and improvement in spatial learning performance.</p> <p>Conclusions</p> <p>Our behavioral findings are consistent with increases in IL-1β and IL-18 that have been previously shown to correlate with spatial learning deficits. Probenecid reduced activated caspase-1 and ameliorated spatial learning deficits in aged rats. Thus, aging processes stimulate activation of the NLRP1 inflammasome and secretion of IL-1β and IL-18 that may contribute to age-related cognitive decline in the growing elderly population. Moreover, probenecid may be potentially useful as a therapy to improve cognitive outcomes in the aging population.</p
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