10 research outputs found

    Embryonic Hypoxia Alters Exploratory Movement in Adult Geckos

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    Environmental changes, such as temporary hypoxia, during the embryonic stage can impair brain development in leopard geckos (Eublepharis macularius). We therefore tested whether this early brain damage produces behavioral deficits that persist into adulthood. The organization and kinematic properties of non-visual exploration between normal (n = 14) and hypoxia (n = 3) geckos were compared. Geckos were individually placed on a circular table (diam=91cm) and allowed to explore darkness for 60min while being recorded. The gecko\u27s coordinates were calculated at 5frames/second. Movement properties within each trial were evaluated across five 10min epochs. Total distance, peak speed, movement scaling (correlation between path length and peak speed), distance ratio, heading error, total stop time, mean stop time, number of stops, number of progressions, and progression distance were compared between groups and across epochs with a mixed Group X Epoch ANOVA. Movement properties did not differ across time epochs. However, hypoxia animals showed significantly lower peak speed [F(1,15) = 6.18, p = .025], and greater movement scaling [F(1,15) = 5.78, p = .03] scores, compared to controls. These results indicate that brain damage caused by early hypoxia causes adult geckos to move slowly, but they retain the ability to move normally and accurately estimate distance. Thus, the reduced speed is not caused by a general movement deficit. These preliminary results suggest that embryonic hypoxia alters exploratory behavior that persists into adulthood. This on-going study will continue to evaluate exploratory movement, and data will be added to the presentation as they become available

    Neuronal Density in Navigation-Related Regions of the Adult Leopard Gecko Brain

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    Hypoxic conditions disrupt brain development in many species, but oxygen deprivation may be particularly detrimental to ectotherms such as reptiles. Our preliminary data suggest the brains of embryonic leopard geckos (Eublepharis macularius) are damaged following brief hypoxic conditions in ovo, and these developmental changes are associated with altered exploratory behavior in adulthood. The objective of this study is to understand the effects of such hypoxic conditions neuronally once the geckos have reached adulthood. However, no previous studies have evaluated the neuronal density of navigation-related brain regions in normal adult geckos, or whether these regions are sensitive to early hypoxia. Here, we present the optical density measurements from the medial cortex, the dorsal and lateral cortex, the dorsal lateral thalamus, and the septal region of adult geckos (n=2) that developed in normoxic conditions, to establish a baseline measure of cell density. Mean (SEM) optical density values are shown in the Table. These optical density values provide an important baseline for our on-going evaluation of neuronal sensitivity to hypoxic conditions in ovo. We anticipate that neuronal density values from hypoxic geckos will be reduced, relative to those of geckos that develop in normoxic conditions

    Protocol update for a randomised controlled feasibility trial of exercise rehabilitation for people with postural tachycardia syndrome: the PULSE study

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    BACKGROUND: The PULSE (PostUraL tachycardia Syndrome Exercise) study is a randomised controlled trial assessing the feasibility of conducting a multicentre RCT testing supervised exercise rehabilitation with behavioural and motivational support, compared to best-practice usual care, for people with Postural Tachycardia Syndrome (PoTS). The original trial protocol was published in BMC Pilot & Feasibility Studies (accessible at https://doi.org/10.1186/s40814-020-00702-1 ). The PULSE intervention consists of (1) individual assessment; (2) 12-week, twice-weekly, supervised exercise training; (3) behavioural and motivational support; and (4) guided lifestyle physical activity. The control intervention is best-practice usual care with a single 30-min, one-to-one practitioner appointment, and general advice on safe and effective physical activity. Sixty-two people (aged 18-60 years) with a confirmed diagnosis of PoTS will be invited to enrol on a feasibility RCT with an embedded qualitative study. The primary outcome will be feasibility; process-related measures will include eligibility, recruitment, randomisation and withdrawal rates, along with indicators of exercise programme adherence and acceptability. Secondary physiological, clinical and health-related outcomes will be assessed. In response to the COVID-19 pandemic, here we describe amendments to the trial protocol. METHODS: Restrictions imposed by the COVID-19 pandemic meant it was necessary to change the delivery of the PULSE and control interventions. These changes reflected the need to limit the risk of COVID-19 transmission in a clinical population, some of whom were at increased risk of contracting the virus and suffering serious illness. The major change was that the originally intended centre-based PULSE and control interventions would now be delivered remotely on-line. Subsequently, there were minor changes to the participant eligibility criteria. These decisions followed an on-line co-creation session with people affected by PoTS, and relevant public and professional stakeholders. CONCLUSIONS: We present an update of the original trial protocol in response to the COVID-19 pandemic. No participants were recruited to the original protocol; thus, results will reflect the on-line delivery of the intervention. PULSE will be the first randomised trial to assess the feasibility of conducting a definitive multi-centre RCT testing supervised on-line exercise rehabilitation with behavioural and motivational support, compared to best-practice usual care, for people with PoTS. TRIAL REGISTRATION: ISRCTN45323485 registered on 7 April 2020

    Protocol update for a randomised controlled feasibility trial of exercise rehabilitation for people with postural tachycardia syndrome: the PULSE study

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    BACKGROUND: The PULSE (PostUraL tachycardia Syndrome Exercise) study is a randomised controlled trial assessing the feasibility of conducting a multicentre RCT testing supervised exercise rehabilitation with behavioural and motivational support, compared to best-practice usual care, for people with Postural Tachycardia Syndrome (PoTS). The original trial protocol was published in BMC Pilot & Feasibility Studies (accessible at https://doi.org/10.1186/s40814-020-00702-1 ). The PULSE intervention consists of (1) individual assessment; (2) 12-week, twice-weekly, supervised exercise training; (3) behavioural and motivational support; and (4) guided lifestyle physical activity. The control intervention is best-practice usual care with a single 30-min, one-to-one practitioner appointment, and general advice on safe and effective physical activity. Sixty-two people (aged 18-60 years) with a confirmed diagnosis of PoTS will be invited to enrol on a feasibility RCT with an embedded qualitative study. The primary outcome will be feasibility; process-related measures will include eligibility, recruitment, randomisation and withdrawal rates, along with indicators of exercise programme adherence and acceptability. Secondary physiological, clinical and health-related outcomes will be assessed. In response to the COVID-19 pandemic, here we describe amendments to the trial protocol. METHODS: Restrictions imposed by the COVID-19 pandemic meant it was necessary to change the delivery of the PULSE and control interventions. These changes reflected the need to limit the risk of COVID-19 transmission in a clinical population, some of whom were at increased risk of contracting the virus and suffering serious illness. The major change was that the originally intended centre-based PULSE and control interventions would now be delivered remotely on-line. Subsequently, there were minor changes to the participant eligibility criteria. These decisions followed an on-line co-creation session with people affected by PoTS, and relevant public and professional stakeholders. CONCLUSIONS: We present an update of the original trial protocol in response to the COVID-19 pandemic. No participants were recruited to the original protocol; thus, results will reflect the on-line delivery of the intervention. PULSE will be the first randomised trial to assess the feasibility of conducting a definitive multi-centre RCT testing supervised on-line exercise rehabilitation with behavioural and motivational support, compared to best-practice usual care, for people with PoTS. TRIAL REGISTRATION: ISRCTN45323485 registered on 7 April 2020

    Estimating Probability Distributions of Travel Times by Fitting a Markovian Velocity Model

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    To improve the routing decisions of individual drivers and the management policies designed by traffic operators, one needs reliable estimates of travel time distributions. Since congestion caused by both recurrent patterns (e.g., rush hours) and non-recurrent events (e.g., traffic incidents) leads to potentially substantial delays in highway travel times, we focus on a framework capable of incorporating both effects. To this end, we propose to work with the Markovian velocity model, based on an environmental background process that tracks both random and (semi-)predictable events affecting the vehicle speeds in a highway network. We show how to operationalize this flexible data-driven model in order to obtain the travel time distribution for a vehicle departing at a known day and time to traverse a given path. Specifically, we detail how to structure the background process and set the speed levels corresponding to the different states of this process. First, for the inclusion of non-recurrent events, we study incident data to describe the random durations of the incident and inter-incident times for different periods of day. Second, for an estimation of the speed patterns in both incident and inter-incident regime, loop detector data for each of these periods is studied. In numerical examples that use road network detector data of the Dutch highway network, we obtain the travel time distribution estimates that arise under different traffic regimes, and illustrate the advantages compared to deterministic travel time prediction methods, or methods that only take recurrent patterns into account.</p

    A framework for efficient dynamic routing under stochastically varying conditions

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    Despite measures to reduce congestion, occurrences of both recurrent and non-recurrent congestion cause large delays in road networks with important economic implications. Educated use of Intelligent Transportation Systems (ITS) can significantly reduce travel times. We focus on a dynamic stochastic shortest path problem: our objective is to minimize the expected travel time of a vehicle, assuming the vehicle may adapt the chosen route while driving. We introduce a new stochastic process that incorporates ITS information to model the uncertainties affecting congestion in road networks. A Markov-modulated background process tracks traffic events that affect the speed of travelers. The resulting continuous-time routing model allows for correlation between velocities on the arcs and incorporates both recurrent and non-recurrent congestion. Obtaining the optimal routing policy in the resulting semi-Markov decision process using dynamic programming is computationally intractable for realistic network sizes. To overcome this, we present the edsger⋆ algorithm, a Dijkstra-like shortest path algorithm that can be used dynamically with real-time response. We develop additional speed-up techniques that reduce the size of the network model. We quantify the performance of the algorithms by providing numerical examples that use road network detector data for The Netherlands

    A framework for efficient dynamic routing under stochastically varying conditions

    Get PDF
    Despite measures to reduce congestion, occurrences of both recurrent and non-recurrent congestion cause large delays in road networks with important economic implications. Educated use of Intelligent Transportation Systems (ITS) can significantly reduce travel times. We focus on a dynamic stochastic shortest path problem: our objective is to minimize the expected travel time of a vehicle, assuming the vehicle may adapt the chosen route while driving. We introduce a new stochastic process that incorporates ITS information to model the uncertainties affecting congestion in road networks. A Markov-modulated background process tracks traffic events that affect the speed of travelers. The resulting continuous-time routing model allows for correlation between velocities on the arcs and incorporates both recurrent and non-recurrent congestion. Obtaining the optimal routing policy in the resulting semi-Markov decision process using dynamic programming is computationally intractable for realistic network sizes. To overcome this, we present the edsger⋆ algorithm, a Dijkstra-like shortest path algorithm that can be used dynamically with real-time response. We develop additional speed-up techniques that reduce the size of the network model. We quantify the performance of the algorithms by providing numerical examples that use road network detector data for The Netherlands

    Supporting dataset for the bachelor thesis: Simulating the Spread of COVID-19 in the Netherlands

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    These files are videos generated by a stochastic simulation that was created by Nikki Steenbakkers under the supervision of Marko Boon and Bert Zwart (all affiliated with Eindhoven University of Technology) for her bachelor final project "Simulating the Spread of COVID-19 in the Netherlands". The report can be found in the TU/e repository of bachelor project reports: https://research.tue.nl/en/studentTheses/simulating-the-spread-of-covid-19-in-the-netherlands The report contains more information about the project and the simulation. It explicitly refers to these files

    An interactive mobile app game to address aggression (RegnaTales) : pilot quantitative study

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    Background: The rapid advancement in media technology has radically changed the way we learn and interact with one another. Games, with their engaging and interactive approach, hold promise in the delivery of knowledge and building of skills. This has potential in child and adolescent mental health work, where the lack of insight and motivation for therapy are major barriers to treatment. However, research on the use of serious games in mental health interventions for children and adolescents is still in its infancy. Objective: This study adds to the research on serious games in mental health interventions through the development and evaluation of RegnaTales, a series of 6 mobile apps designed to help children and adolescents manage anger. We examined the usability and playability of RegnaTales, as well as children’s aggression levels before and after the game play. Methods: A total of 72 children aged between 6 and 12 years were recruited for the study. Thirty-five participants had a clinical diagnosis of disruptive behavior disorders (DBD), whereas 37 were typically developing (TD) children. Each child played 1 of the 6 RegnaTales apps for approximately 50 min before completing the Playability and Usability Questionnaire. The Reactive-Proactive Aggression Questionnaire was completed before and after the game play. Results: The overall results showed high levels of enjoyment and playability. TD children and children with DBD had similar experienced fun and perceived playability scores on all 6 mobile apps. All 6 mobile apps garnered comparable experienced fun and perceived playability scores. Furthermore, 42% (5/12) to 67% (8/12) of the children indicated that they would like to play the games again. Importantly, children felt that they acquired skills in anger management, were motivated to use them in their daily lives, and felt confident that the skills would help them better manage their anger. Children reported significantly lower reactive aggression after playing the mobile apps Rage Raver (P=.001), Abaddon (P=.008), and RegnaTools (P=.03). These apps focused on the psychoeducation of the link between thoughts and emotions, as well as equipping the participants with various emotion regulation strategies such as relaxation and cognitive restructuring. Conclusions: This study presents evidence to support RegnaTales as a feasible serious game. The preliminary findings associated with reduction in reactive aggression, coupled with future research to further establish its efficacy, could warrant RegnaTales as a potential intervention for anger issues among clinical and community populations.NMRC (Natl Medical Research Council, S’pore)Published versio
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