Are train horns improving road safety? Road users' perspective.

Train horns are used as a control at railway level crossing for safety. Despite their wide use, limited information exists on their actual safety benefits. This study used focus groups with road users to understand their perceptions of the usefulness of train horns. This study showed that the message heard by road users is very simple and contrasts with the amount of information train drivers want to convey. The perceived benefits of the train horn were: (i) an additional layer of protection at active crossings; (ii) an important safety feature at rural/passive crossings; (iii) an increased safety benefit for vulnerable road users; and (iv) a greater safety benefit at night. The disadvantages of the use of train horns were perceived as outweighed by the safety benefits. This study highlights that reducing train horns, if safe to do so, could face resistance from road users and the rail industry.

The safety benefits of train horns at railway level crossings are not well-researched, despite their negative effects on health. This focus group study investigated road users' perceptions of the usefulness of train horns. It showed that reducing the use of train horns could face resistance from road users.

Risk mitigation at train stations: underlying causes of slips, trips, and falls for passengers with reduced mobility.

Slips, trips, and falls (STFs) occur frequently at train stations and on trains, and result in passengers injuries. STFs underlying causes focussing on passengers with reduced mobility (PRM) were investigated. Mixed methods combining observation and retrospective interviews were used. Thirty-seven participants between 24 and 87 years of age completed the protocol. They navigated between three selected stations while wearing the Tobii eye tracker. In retrospective interviews, they were asked to explain their actions in selected video segments. The research identified the dominant risky locations and risk-taking behaviour in risky locations. For example: (i) risky locations were the vicinity of obstacles, (ii) risky behaviour was not looking at the gap between the platform and train. The dominant risky locations and behaviours could be considered as underlying causes of slips, trips, and falls for PRMs. They can be applied during planning and design of rail infrastructure to predict and mitigate STFs.Practitioner summary: A significant number of slips, trips, and falls (STFs) occurs at railway stations, and often result in personal injury. This research identified the dominant risky locations and behaviour as underlying causes of STFs for people with reduced mobility (PRMs). The recommendations presented could be implemented to mitigate such risk.

Voluntary running attenuates behavioural signs of low back pain: dimorphic regulation of intervertebral disc inflammation in male and female SPARC-null mice.

OBJECTIVE: To examine the effect of running exercise on behavioral measures of pain and intervertebral disc (IVD) inflammation in the SPARC-null mouse model. METHODS: Male and female 8-month old SPARC-null and age-matched control mice received a home cage running wheel or a control, fixed wheel for 6 months. Behavioral assays were performed to assess axial discomfort (grip test) and radiating leg pain (von Frey, acetone tests) and voluntary running was confirmed. Expression of inflammatory mediators (TNF-α, IL-1ß, IL-2, IL-10, CCL5, CXCL1, CXCL5, RANKL, M-CSF, and VEGF) in IVDs was determined. Additional inflammatory (IL-1ß, IL-1Ra, CXCR1, CXCR2) and macrophage phenotypic markers (ITGAM, CD80, CD86, CD206, Arg1) in IVDs were investigated by qPCR. RESULTS: Voluntary running attenuated behavioral measures of pain in male and female SPARC-null mice. Increases in mediators including IL-1ß, CXCL1 and CXCL5 were observed in SPARC-null compared to control IVDs. After 6 months of running, increases in M-CSF and VEGF were observed in male SPARC-null IVDs. In females, pro-inflammatory mediators, including CXCL1 and CXCL5 were downregulated by running in SPARC-null mice. qPCR analysis further confirmed the anti-inflammatory effect of running in female IVDs with increased IL-1Ra mRNA. Running induced upregulation of the macrophage marker ITGAM mRNA in males. CONCLUSIONS: Voluntary running reversed behavioral signs of pain in male and female mice and reduced inflammatory mediators in females, but not males. Thus, the therapeutic mechanism of action may be sex-specific.

Low levels of refractive blur increase the risk of colour misperception of red train signals.

PURPOSE: Red signals signify danger in a range of situations, including train operations. Importantly, misperception of a red signal as yellow can have serious safety implications. This study investigated the effects of lens blur on incorrect colour perception of red signals, which has been implicated in previous train crashes. METHODS: Participants included 15 young (26.6 ± 4.6 years) and 15 older (55.8 ± 3.1 years) visually normal adults. Red and yellow wayside train signals were simulated for two brightness levels (dim, bright) using a custom-built projection system. The effect of blur (best-corrected refraction [No Blur], +0.25 DS, +0.50 DS, +0.75 DS, +1.00 DS, +1.25 DS) on the number of incorrect colour perception responses of the signals was recorded. The order of conditions was randomised between participants. RESULTS: For incorrect responses to the red signal, there were significant main effects of blur (p < 0.001) and signal brightness (p < 0.001) and a significant interaction between blur and brightness (p < 0.001). The effects of blur were greater for the dim compared to the bright signals, with significantly higher colour misperceptions for the dim signal for +0.50 DS blur and higher, compared with No Blur. Colour misperceptions of the yellow signals were low compared with that of the red signals, with only +1.25 DS blur resulting in a significantly higher number of incorrect responses than No Blur (p < 0.001). There were no effects of age for the red or yellow colour misperceptions (p > 0.19). CONCLUSIONS: Low levels of blur (+0.50 DS to +1.25 DS) resulted in a significant misperception of the red signals as orange-yellow, particularly for dim signals. The findings have implications for vision testing and refractive correction of train drivers to minimise the possibility of colour misperception of red train signals.

Comparison of the metabolism of 10 chemicals in human and pig skin explants.

Skin metabolism is important to consider when assessing local toxicity and/or penetration of chemicals and their metabolites. If human skin supply is limited, pig skin can be used as an alternative. To identify any species differences, we have investigated the metabolism of 10 chemicals in a pig and human skin explant model. Phase I metabolic pathways in skin from both species included those known to occur via cytochrome P450s, esterases, alcohol dehydrogenases and aldehyde dehydrogenases. Common Phase II pathways were glucuronidation and sulfation but other conjugation pathways were also identified. Chemicals not metabolized by pig skin (caffeine, IQ and 4-chloroaniline) were also not metabolized by human skin. Six chemicals metabolized by pig skin were metabolized to a similar extent (percentage parent remaining) by human skin. Human skin metabolites were also detected in pig skin incubations, except for one unidentified minor vanillin metabolite. Three cinnamyl alcohol metabolites were unique to pig skin but represented minor metabolites. There were notable species differences in the relative amounts of common metabolites. The difference in the abundance of the sulfate conjugates of resorcinol and 4-amino-3-nitrophenol was in accordance with the known lack of aryl sulfotransferase activity in pigs. In conclusion, while qualitative comparisons of metabolic profiles were consistent between pig and human skin, there were some quantitative differences in the percentage of metabolites formed. This preliminary assessment suggests that pig skin is metabolically competent and could be a useful tool for evaluating potential first-pass metabolism before testing in human-derived tissues.

Dietary omega-3 deficiency exacerbates inflammation and reveals spatial memory deficits in mice exposed to lipopolysaccharide during gestation.

Maternal immune activation (MIA) is a common environmental insult on the developing brain and represents a risk factor for neurodevelopmental disorders. Animal models of in utero inflammation further revealed a causal link between maternal inflammatory activation during pregnancy and behavioural impairment relevant to neurodevelopmental disorders in the offspring. Accumulating evidence point out that proinflammatory cytokines produced both in the maternal and fetal compartments are responsible for social, cognitive and emotional behavioral deficits in the offspring. Polyunsaturated fatty acids (PUFAs) are essential fatty acids with potent immunomodulatory activities. PUFAs and their bioactive derivatives can promote or inhibit many aspects of the immune and inflammatory response. PUFAs of the n-3 series ('n-3 PUFAs', also known as omega-3) exhibit anti-inflammatory/pro-resolution properties and promote immune functions, while PUFAs of the n-6 series ('n-6 PUFAs' or omega-6) favor pro-inflammatory responses. The present study aimed at providing insight into the effects of n-3 PUFAs on the consequences of MIA on brain development. We hypothesized that a reduction in n-3 PUFAs exacerbates both maternal and fetal inflammatory responses to MIA and later-life defects in memory in the offspring. Based on a lipopolysaccharide (LPS) model of MIA (LPS injection at embryonic day 17), we showed that n-3 PUFA deficiency 1) alters fatty acid composition of the fetal and adult offspring brain; 2) exacerbates maternal and fetal inflammatory processes with no significant alteration of microglia phenotype, and 3) induces spatial memory deficits in the adult offspring. We also showed a strong negative correlation between brain content in n-3 PUFA and cytokine production in MIA-exposed fetuses. Overall, our study is the first to address the deleterious effects of n-3 PUFA deficiency on brain lipid composition, inflammation and memory performances in MIA-exposed animals and indicates that it should be considered as a potent environmental risk factor for the apparition of neurodevelopmental disorders.

Validation of a Driving Simulator Study on Driver Behavior at Passive Rail Level Crossings.

OBJECTIVE: The behavioral validation of an advanced driving simulator for its use in evaluating passive level crossing countermeasures was performed for stopping compliance and speed profile. BACKGROUND: Despite the fact that most research on emerging interventions for improving level crossing safety is conducted in a driving simulator, no study has validated the use of a simulator for this type of research. METHOD: We monitored driver behavior at a selected passive level crossing in the Brisbane region in Australia for 3 months ( N = 916). The level crossing was then replicated in an advanced driving simulator, and we familiarized participant drivers ( N = 54) with traversing this crossing, characterized by low road and rail traffic. RESULTS: We established relative validity for the stopping compliance and the approach speed. CONCLUSION: This validation study suggests that driving simulators are an appropriate tool to study the effects of interventions at passive level crossing with low road and rail traffic, which are prone to reduced compliance due to familiarity. APPLICATION: This study also provides support for the findings of previous driving simulator studies conducted to evaluate compliance and approach speeds of passive level crossings.

Comparison of protocols measuring diffusion and partition coefficients in the stratum corneum.

Partition (K) and diffusion (D) coefficients are important to measure for the modelling of skin penetration of chemicals through the stratum corneum (SC). We compared the feasibility of three protocols for the testing of 50 chemicals in our main studies, using three cosmetics-relevant model chemicals with a wide range of logP values. Protocol 1: SC concentration-depth profile using tape-stripping (measures KSC/v and DSC /HSC2 , where HSC is the SC thickness); Protocol 2A: incubation of isolated SC with chemical (direct measurement of KSC/v only) and Protocol 2B: diffusion through isolated SC mounted on a Franz cell (measures KSC/v and DSC /HSC2 , and is based on Fick's laws). KSC/v values for caffeine and resorcinol using Protocol 1 and 2B were within 30% of each other, values using Protocol 2A were ~two-fold higher, and all values were within 10-fold of each other. Only indirect determination of KSC/v by Protocol 2B was different from the direct measurement of KSC/v by Protocol 2A and Protocol 1 for 7-EC. The variability of KSC/v for all three chemicals using Protocol 2B was higher compared to Protocol 1 and 2A. DSC /HSC2 values for the three chemicals were of the same order of magnitude using all three protocols. Additionally, using Protocol 1, there was very little difference between parameters measured in pig and human SC. In conclusion, KSC/v, and DSC values were comparable using different methods. Pig skin might be a good surrogate for human skin for the three chemicals tested. Copyright © 2017 The Authors Journal of Applied Toxicology published by John Wiley & Sons Ltd.

Looking back in the rearview: Insights into Queensland's rear-end crashes.

OBJECTIVE: Rear-end crashes cost the most out of any crash type to the Compulsory Third Party insurance scheme of Queensland. Rear-end crashes are also one of the most common types of crashes, peaking as the most common type of crash in Queensland in 2019. This study investigated the environmental, driver, and vehicle characteristics associated with rear-end collisions in Queensland, Australia. METHODS: A totle of 367,230 crashes in the Queensland crash database between 2001 and 2021 were used to identify crash trends in Queensland, particularly related to rear-end crashes. For crashes between 2015 and 2021, additional information was gathered and allowed further analysis of factors contributing to rear-end crashes using the quasi-induced exposure method. Two binary classification tree models were used. Model 1 investigated the environmental characteristics that predicted a crash being a rear-end or not. Model 2 investigated the controller and vehicle characteristics that predict a rear-end crash-involved vehicle to be either the striking (at-fault) or struck (not-at-fault) vehicle. RESULTS: Model 1 indicated that rear-end crashes were overrepresented in urban areas and major cities and where speed limits exceeded 50 km/h. Model 2 indicated that occupants of struck vehicles (not at-fault) were more likely to be severely injured than the striking (at-fault) vehicles in rear-end crashes. License type and vehicle type also influenced the frequency and severity of rear-end crashes. CONCLUSION: Rear-end crashes can be unjust in that the not-at-fault party is typically more severely injured. Results from the current study suggest that keeping speed limits no higher than 50 km/h could help reduce the severity of rear-end crashes. Increased enforcement of safe following distances could also assist in preventing road trauma as a result of rear-end crashes.

Effectiveness of interventions for mobile phone distracted pedestrians: A systematic review.

INTRODUCTION: Mobile phones are used universally due to their versatility and easy-to-use features; this includes when users are walking and when crossing streets. At intersections, using a mobile phone is a secondary task that can distract from the primary task of scanning the road environment and ensuring it is safe to traverse. Such a distraction has been shown to increase risky pedestrian behavior compared to non-distracted behavior. Developing an intervention to make distracted pedestrians aware of imminent danger is a promising approach to refocus pedestrians on their primary task and avoid incidents. Interventions have already been developed in different parts of the world, such as in-ground flashing lights, painted crosswalks, and mobile phone app-based warning systems. METHOD: A systematic review of 42 articles was performed to determine the effectiveness of such interventions. This review found that three types of interventions are currently developed, with differing evaluations. Interventions based on infrastructure tend to be evaluated based on behavioral change. Mobile phone-based apps tend to be evaluated on their ability to detect obstacles. Legislative changes and education campaigns are not currently evaluated. Further, technological development often occurs independently of pedestrians' needs, reducing the likely safety benefits of such interventions. The interventions related to infrastructure mainly focus on warning pedestrians without considering pedestrian mobile phone use, potentially leading to numerous irrelevant warnings and reduced user acceptance. The lack of a comprehensive and systematic approach to evaluating these interventions is also an issue requiring consideration. PRACTICAL APPLICATIONS: This review demonstrates that despite significant recent progress surrounding pedestrian distraction, more work is required to identify the most effective interventions to implement. Future studies with a well-designed experimental framework are necessary to compare the different approaches, and warning messages, and ensure the best guidance for road safety agencies.

The prototype willingness model: An application to adolescent driver speeding.

INTRODUCTION: Many young drivers are involved in crashes due to speeding. Some studies have used the Prototype Willingness Model (PWM) to explain the risky driving behavior of young people. However, many have measured PWM constructs in a manner inconsistent with its formulation. The PWM asserts that the social reaction pathway is underpinned by a heuristic comparison of oneself with a cognitive prototype of someone who engages in a risky behavior. This proposition has not been comprehensively examined and few PWM studies specifically examine social comparison. The current study investigates intentions, expectations, and willingness to speed by teen drivers using operationalizations of PWM constructs more aligned with their original conceptualizations. Additionally, the influence of dispositional social comparison tendency on the social reaction pathway is examined to further test the original propositions underpinning the PWM. METHOD: Two hundred and eleven independently driving adolescents completed an online survey including items measuring PWM constructs and social comparison tendency. Hierarchical multiple regression was used to investigate the influence of perceived vulnerability, descriptive and injunctive norms, and prototypes on speeding intentions, expectations, and willingness. A moderation analysis examined the effect of social comparison tendency on the association between prototype perceptions and willingness. RESULTS: The regression models explained substantial amounts of variance in intentions (39%), expectations (49%), and willingness (30%) to speed. There was no evidence that social comparison tendency influences the relationship between prototypes and willingness. CONCLUSIONS: The PWM is useful for predicting teenage risky driving. More studies should confirm that social comparison tendency does not moderate the social reaction pathway. However, there may be need for further theoretical development of the PWM. PRACTICAL APPLICATIONS: The study suggests that it may be possible to develop interventions to reduce adolescent driver speeding based on manipulation of PWM constructs such as speeding driver prototypes.

Factors reducing the detectability of train horns by road users: A laboratory study.

Level crossing safety is a well-researched safety issue worldwide, but little attention has been placed on the safety benefits of using train horns when a train approaches a level crossing. Given train horns' adverse effects on the health and well-being of residents living near rail tracks, the use of train horns must be beneficial to safety. The current study sought to determine in a laboratory environment whether road users (N = 31) can detect the range of train horns observed in Australia in terms of loudness and duration, using high-definition audio recordings from railway crossings. A repeated measures design was used to evaluate the effects of key factors likely to influence the detectability of train horns, including, visual and auditory distractive tasks, hearing loss and environmental noise (crossing bells). Train horn detectability was assessed based on participants' accuracy and reaction times. Results indicated the duration of the train horn had the most influential effect on the detectability of train horns, with short-duration train horns less likely to be detected. The presence of bells at a crossing was the second most important factor that limited train horn detection. Train horn loudness also affected detectability: faint blasts were less likely to be noticed, while loudest blasts were more likely to be noticed. However, loud horns reduced the ability to detect the side from which the train was approaching and may result in longer times to detect the train, in the field. The auditory distractive task reduced the train horn detection accuracy and increased reaction time. However, the visual distractive task and medium to severe hearing loss were not found to affect train horn detection. This laboratory study is the first to provide a broad understanding of the factors that affect the detectability of Australian train horns by road users. The findings from this study provide important insights into ways to reduce the use and modify the practice to mitigate the negative effects of train horns while maintaining the safety of road users.

Cerebral microbleeds and long-term cognitive outcome: longitudinal cohort study of stroke clinic patients.

BACKGROUND: Vascular cognitive impairment causes significant disability in the elderly and is common following ischaemic stroke. Although the underlying mechanisms and prognostic factors remain unclear, small vessel diseases are known to contribute. Cerebral microbleeds (CMBs) are a magnetic resonance imaging (MRI) manifestation of small vessel diseases and may contribute to vascular cognitive impairment, particularly frontal-executive functions. We hypothesized that baseline CMBs would predict long-term cognitive outcome, specifically frontal-executive function. METHODS: A cohort of consecutive patients found to have CMBs when first referred to a stroke clinic, together with a CMB-free control group matched for age, gender and clinicoradiological characteristics, were invited for follow-up cognitive assessment a median of 5.7 years later. MRI and detailed cognitive assessment (including current intellectual function, verbal memory, visual memory, naming skills, perceptual functions, frontal-executive functions; and speed and attention) were performed at baseline and follow-up. Patients were classified (blinded to MRI and clinical data) as impaired or unimpaired in each domain using predefined criteria. We compared the prevalence of cognitive impairments in each domain at baseline and follow-up and investigated clinical and radiological predictors [including baseline CMBs and white matter changes (WMCs)] of frontal-executive cognitive impairment. RESULTS: Of the original cohort of 55 patients, 13 died without follow-up. Twenty-six of the surviving patients (9 with, 17 without baseline CMBs) agreed to follow-up neuropsychological assessment; 21 of these patients had a repeat MRI scan. The median number of cognitive domains impaired increased, regardless of the presence of baseline CMBs (with baseline CMBs: median 3, range 0-5 at follow-up vs. median 2, range 0-2 at baseline, p = 0.016; without CMBs: median 1.0, range 0-5 at follow-up vs. median 0, range 0-5 at baseline, p = 0.035). Frontal-executive impairment at follow-up was more prevalent in patients with baseline CMBs than in those without (78 vs. 29%, p = 0.038). The presence of baseline CMBs predicted frontal-executive impairment at follow-up (OR 8.40, 95% CI 1.27-55.39, p = 0.027). Fifty percent of patients with CMBs versus 8% of patients without baseline CMBs developed new CMBs (p = 0.047). The severity of WMCs increased; the difference was statistically significant only in patients without baseline CMBs (p = 0.027). There were no new cortical infarcts. CONCLUSION: In stroke clinic patients, CMBs are consistently associated with frontal-executive impairment; baseline CMBs are associated with frontal-executive impairment at follow-up after 5.7 years. The presence of CMBs has prognostic relevance for long-term cognitive outcome in stroke clinic patients, and may help to optimally target preventive strategies in individuals at highest risk of cognitive decline.

Physiological signal-based drowsiness detection using machine learning: Singular and hybrid signal approaches.

INTRODUCTION: Drowsiness is one of the main contributors to road-related crashes and fatalities worldwide. To address this pressing global issue, researchers are continuing to develop driver drowsiness detection systems that use a variety of measures. However, most research on drowsiness detection uses approaches based on a singular metric and, as a result, fail to attain satisfactory reliability and validity to be implemented in vehicles. METHOD: This study examines the utility of drowsiness detection based on singular and a hybrid approach. This approach considered a range of metrics from three physiological signals - electroencephalography (EEG), electrooculography (EOG), and electrocardiography (ECG) - and used subjective sleepiness indices (assessed via the Karolinska Sleepiness Scale) as ground truth. The methodology consisted of signal recording with a psychomotor vigilance test (PVT), pre-processing, extracting, and determining the important features from the physiological signals for drowsiness detection. Finally, four supervised machine learning models were developed based on the subjective sleepiness responses using the extracted physiological features to detect drowsiness levels. RESULTS: The results illustrate that the singular physiological measures show a specific performance metric pattern, with higher sensitivity and lower specificity or vice versa. In contrast, the hybrid biosignal-based models provide a better performance profile, reducing the disparity between the two metrics. CONCLUSIONS: The outcome of the study indicates that the selected features provided higher performance in the hybrid approaches than the singular approaches, which could be useful for future research implications. Practical Applications: Use of a hybrid approach seems warranted to improve in-vehicle driver drowsiness detection system. Practical applications will need to consider factors such as intrusiveness, ergonomics, cost-effectiveness, and user-friendliness of any driver drowsiness detection system.

Prevalence and dynamics of distracted pedestrian behaviour at railway level crossings: Emerging issues.

Recent increases in pedestrian collisions have led to several studies investigating the effects of distraction on pedestrian behaviour at road intersections. Although distraction has been identified as a contributing factor to pedestrian crashes at railway crossings, only limited research is available regarding the prevalence of this behaviour occurring at railway level crossings. It is, therefore, essential to better understand distraction prevalence at railway crossings to support the use of countermeasures to improve safety outcomes. We conducted field observations at a railway crossing in Brisbane, Australia and its adjacent road intersection to gauge the prevalence of distracted pedestrians. Overall, 585 pedestrians were observed and video recorded during the daytime. The video recordings were coded to estimate the prevalence of distraction behaviour that road users engaged in, factors that affected these proportions, and dynamic changes in behaviour. Compliance with signals was also analysed. We found distraction behaviours such as talking and looking at the mobile screen (41.9%) while walking to be prevalent and affected by age. Highly distractive tasks were found to be less commonplace at the railway crossing, accounting for 3% of the observations. Still, pedestrians at the railway crossing engaged in these highly distractive tasks on their phones for a much longer period of time. While most non-compliances (with traffic lights) occurred among attentive pedestrians and are likely to be intentional, non-compliances by distracted pedestrians were also observed, highlighting that distraction can lead to unsafe decisions or lack of decisions that result in unsafe behaviours. Finally, distraction was found to be a dynamic phenomenon as a few pedestrians stopped engaging in distractive tasks once they reached the crossing, while others engaged in more distractive tasks once they were on the road or crossing. Our study shows that pedestrian distraction is a prevalent issue at railway crossings and future research is required to further understand and mitigate this changing behaviour.

An on-road examination of daytime and evening driving on rural roads: physiological, subjective, eye gaze, and driving performance outcomes.

Experiencing sleepiness when driving is associated with increased crash risk. An increasing number of studies have examined on-road driver sleepiness; however, these studies typically assess the effect of sleepiness during the late night or early morning hours when sleep pressure is approaching its greatest. An on-road driving study was performed to assess how a range of physiological and sleepiness measures are impacted when driving during the daytime and evening when moderate sleepiness is experienced. In total, 27 participants (14 women and 13 men) completed a driving session in a rural town lasting approximately 60 minutes, while physiological sleepiness (heart rate variability), subjective sleepiness, eye tracking data, vehicle kinematic data and GPS speed data were recorded. Daytime driving sessions began at 12:00 or 14:00, with the evening sessions beginning at 19:30 or 20:30; only a subset of participants (n = 11) completing the evening sessions (daytime and evening order counterbalanced). The results suggest reductions in the horizontal and vertical scanning ranges occurred during the initial 40 minutes of driving for both daytime and evening sessions, but with evening sessions reductions in scanning ranges occurred across the entire driving session. Moreover, during evening driving there was an increase in physiological and subjective sleepiness levels. The results demonstrate meaningful increases in sleepiness and reductions in eye scanning when driving during both the daytime and particularly in the evening. Thus, drivers need to remain vigilant when driving during the daytime and the evening.

Role of glucosyltransferase B in interactions of Candida albicans with Streptococcus mutans and with an experimental pellicle on hydroxyapatite surfaces.

Candida albicans and mutans streptococci are frequently detected in dental plaque biofilms from toddlers afflicted with early childhood caries. Glucosyltransferases (Gtfs) secreted by Streptococcus mutans bind to saliva-coated apatite (sHA) and to bacterial surfaces, synthesizing exopolymers in situ, which promote cell clustering and adherence to tooth enamel. We investigated the potential role Gtfs may play in mediating the interactions between C. albicans SC5314 and S. mutans UA159, both with each other and with the sHA surface. GtfB adhered effectively to the C. albicans yeast cell surface in an enzymatically active form, as determined by scintillation spectroscopy and fluorescence imaging. The glucans formed on the yeast cell surface were more susceptible to dextranase than those synthesized in solution or on sHA and bacterial cell surfaces (P < 0.05), indicating an elevated α-1,6-linked glucose content. Fluorescence imaging revealed that larger numbers of S. mutans cells bound to C. albicans cells with glucans present on their surface than to yeast cells without surface glucans (uncoated). The glucans formed in situ also enhanced C. albicans interactions with sHA, as determined by a novel single-cell micromechanical method. Furthermore, the presence of glucan-coated yeast cells significantly increased the accumulation of S. mutans on the sHA surface (versus S. mutans incubated alone or mixed with uncoated C. albicans; P < 0.05). These data reveal a novel cross-kingdom interaction that is mediated by bacterial GtfB, which readily attaches to the yeast cell surface. Surface-bound GtfB promotes the formation of a glucan-rich matrix in situ and may enhance the accumulation of S. mutans on the tooth enamel surface, thereby modulating the development of virulent biofilms.

Evaluating the effects of automated monitoring on driver non-compliance at active railway level crossings.

Collisions between road users and trains at urban railway level crossings persist, despite active protection. The number of railway level crossings in most settings render their removal unfeasible. To effectively reduce or manage risk, alternative treatments are required. Increases in road and rail traffic invariably result in congestion issues at urban railway level crossings, which influences non-compliances by road users. Automated enforcement is one form of treatment that is being considered to reduce such non-compliances. This study conceptualised and adopted a before-after design to evaluate the effect of a conspicuous monitoring system on non-compliances by vehicular road users at an active level crossing. Baseline measurements of vehicle movements and level crossing status were recorded for two months. Conspicuous cameras and radar were subsequently installed, and a further month of data was recorded. Non-compliances with flashing lights were extracted and arranged into "must stop" and "should stop if safe to do so" categories, aligning with road rules at traffic lights. Non-compliances frequently occurred (N = 1,086) with most (94%) of the latter category and ascribed to a lack of an advanced warning before crossing closure. Analysis with Generalised Linear Models revealed that non-compliances where drivers must stop reduced by 36% (from 13.4% to 8.6%) following the introduction of a conspicuous automated monitoring system, even though no actual enforcement was performed. This study suggests that non-compliances at railway level crossings have the potential to be reduced through the introduction of automated enforcement similar to the one used at traffic lights.

Sensitivity and specificity of the driver sleepiness detection methods using physiological signals: A systematic review.

Driver sleepiness is a major contributor to road crashes. A system that monitors and warns the driver at a certain, critical level of arousal, could aid in reducing sleep-related crashes. To determine how driver sleepiness detection systems perform, a systematic review of the sensitivity and specificity outcomes was performed. In total, 21 studies were located that met inclusion criteria for the review. The range of sensitivity outcomes was between 39.0-98.8 % and between 73.0-98.9 % for specificity outcomes. There was considerable variation in the outcomes of the studies employing only one physiological measure (mono-signal approach), whereas, a poly-signal approach with multiple physiological signals resulted in more consistency with higher outcomes on both sensitivity and specificity metrics. Only six of the 21 studies had both sensitivity and specificity outcomes above 90.0 %, which included mono- and poly-signal approaches. Moreover, increases in the number of features used in the sleepiness detection system did not result in higher sensitivity and specificity outcomes. Overall, there was considerable variability between the studies reviewed, including measures of ground truth, the features employed and the machine learning approach of the systems. A critical need for progressing any system is a revalidation of the system on a new sample of users. These aspects indicate considerable progress is needed with physiological-based driver sleepiness systems before they are at a sufficient standard to be deployed on-road.

Improving the safety of distracted pedestrians with in-ground flashing lights. A railway crossing field study.

INTRODUCTION: Current signage at intersections is designed for attentive pedestrians who are looking ahead. Such signage may not be sufficient when distracted by smartphones. Illuminated in-ground LED lights at crossings are an innovative solution to alert distracted pedestrians. METHOD: We conducted a field study at a railway crossing equipped with in-ground lights to assess whether distracted pedestrians (N = 34, Mean age 33.6 ±â€¯8.6 years) could detect these lights and how this impacted on their visual scanning and crossing behaviour. This involved a 2 × 3 repeated measures design exploring the impact of the presence (treatment) or absence (control) of in-ground lights (treatment) at a crossing, and a distractor task presented through a mobile device (none, visual, and audio) on eye movements recorded using an eye tracker, and verbal reporting of when participants detected the lights. RESULTS: Participants engaged in the distraction tasks as evidenced by their accuracy and reaction times in all conditions. With both the audio and visual distraction tasks, participants looked at the in-ground LEDs and detected their activation as accurately as when not distracted (95%). While most participants detected the lights at their activation, visual distraction resulted in 10% of the detections occurring as participants entered the rail corridor, suggesting effectiveness in gaining pedestrians' attention. Further, participants were significantly less likely to check for trains when visually distracted (70%), a 10% reduction compared to the no or audio distractor conditions (80% and 78% respectively). The introduction of the in-ground lights resulted in appropriate scanning of the rail tracks (77% and 78% for the visual and auditory distractor tasks respectively) similar to that of non-distracted participants for the crossing without lights (80%). CONCLUSIONS: Our findings indicate that illuminated in-ground lights could be useful in attracting the attention of distracted pedestrians at railway level crossings, and possibly at other road intersections. Practical Applications: Illuminated in-ground lights can be installed at rail and road intersections with known pedestrian distraction as a countermeasure. Further research is necessary to understand their long-term effects.