268 research outputs found

    Research in the general area of non-linear dynamical systems Final report, 8 Jun. 1965 - 8 Jun. 1967

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    Nonlinear dynamical systems research on systems stability, invariance principles, Liapunov functions, and Volterra and functional integral equation

    Physiological Measures of Risk Perception in Highly Automated Driving

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    Highly automated driving will likely result in drivers being out-of-the-loop during specific scenarios and engaging in a wide range of non-driving related tasks. Manifesting in lower levels of risk perception to emerging events, and thus affect drivers' availability to take-over manual control in safety-critical scenarios. In this empirical research, we measured drivers' (N = 20) risk perception with cardiac and skin conductance indicators through a series of high-fidelity, simulated highly automated driving scenarios. By manipulating the presence of surrounding traffic and changing driving conditions as long-term risk modulators, and including a driving hazard event as a short-term risk modulator, we hypothesised that an increase in risk perception would induce greater physiological arousal. Our results demonstrate that heart rate variability features are superior at capturing arousal variations from these long-term, low to moderate risk scenarios. In contrast, skin conductance responses are more sensitive to rapidly evolving situations associated with moderate to high risk. Based on this research, future driver state monitoring systems should adopt multiple physiological measures to capture changes in the long and short term, modulation of risk perception. This will enable enhanced perception of driver readiness and improved availability to safely deal with take-over events when requested by an automated vehicle.</p

    Nonextensive statistical features of the Polish stock market fluctuations

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    The statistics of return distributions on various time scales constitutes one of the most informative characteristics of the financial dynamics. Here we present a systematic study of such characteristics for the Polish stock market index WIG20 over the period 04.01.1999 - 31.10.2005 for the time lags ranging from one minute up to one hour. This market is commonly classified as emerging. Still on the shortest time scales studied we find that the tails of the return distributions are consistent with the inverse cubic power-law, as identified previously for majority of the mature markets. Within the time scales studied a quick and considerable departure from this law towards a Gaussian can however be traced. Interestingly, all the forms of the distributions observed can be comprised by the single qq-Gaussians which provide a satisfactory and at the same time compact representation of the distribution of return fluctuations over all magnitudes of their variation. The corresponding nonextensivity parameter qq is found to systematically decrease when increasing the time scales.Comment: 14 pages. Physica A in prin

    Using fNIRS to Verify Trust in Highly Automated Driving

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    Trust in automation is crucial for the safe and appropriate adoption of automated driving technology. Current research methods to measure trust mainly rely on subjective scales, with several intrinsic limitations. This empirical experiment proposes a novel method to measure trust objectively, using functional near-infrared spectroscopy (fNIRS). Through manipulating participants’ expectations regarding driving automation credibility, we have induced and successfully measured opposing levels of trust in automation. Most notably, our results evidence two separate yet interrelated cortical mechanisms for trust and distrust. Trust is demonstrably linked to decreased monitoring and working memory, whereas distrust is event-related and strongly tied to affective (or emotional) mechanisms. This paper evidence that trust in automation and situation awareness are strongly interrelated during driving automation usage. Our findings are crucial for developing future driver state monitoring technology that mitigates the impact of inappropriate reliance, or over trust, in automated driving systems

    Arcuate AgRP, but not POMC neurons, modulate paraventricular CRF synthesis and release in response to fasting

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    Background: The activation of the hypothalamic–pituitary–adrenal (HPA) axis is essential for metabolic adaptation in response to fasting. However, the neurocircuitry connecting changes in the peripheral energy stores to the activity of hypothalamic paraventricular corticotrophin-releasing factor (CRFPVN) neurons, the master controller of the HPA axis activity, is not completely understood. Our main goal was to determine if hypothalamic arcuate nucleus (ARC) POMC and AgRP neurons can communicate fasting-induced changes in peripheral energy stores, associated to a fall in plasma leptin levels, to CRFPVN neurons to modulate the HPA axis activity in mice. Results: We observed increased plasma corticosterone levels associate with increased CRFPVN mRNA expression and increased CRFPVN neuronal activity in 36 h fasted mice. These responses were associated with a fall in plasma leptin levels and changes in the mRNA expression of Agrp and Pomc in the ARC. Fasting-induced decrease in plasma leptin partially modulated these responses through a change in the activity of ARC neurons. The chemogenetic activation of POMCARC by DREADDs did not affect fasting-induced activation of the HPA axis. DREADDs inhibition of AgRPARC neurons reduced the content of CRFPVN and increased its accumulation in the median eminence but had no effect on corticosterone secretion induced by fasting. Conclusion: Our data indicate that AgRPARC neurons are part of the neurocircuitry involved in the coupling of PVNCRF activity to changes in peripheral energy stores induced by prolonged fasting.Fil: Alves Fernandes, Alan Carlos. University Of Ribeirao Preto; BrasilFil: Pereira de Oliveira, Franciane. Universidade Federal de Sao Paulo.; BrasilFil: Fernandez, Gimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: da Guia Vieira, Luane. University Of Ribeirao Preto; BrasilFil: Gugelmin Rosa, Cristiane. University Of Ribeirao Preto; BrasilFil: do Nascimento, Taís. University Of Ribeirao Preto; BrasilFil: de Castro França, Suzelei. University Of Ribeirao Preto; BrasilFil: Donato Jr, Jose. Universidade de Sao Paulo. Departamento de Fisiología; BrasilFil: Vella, Kristen R.. Weill Cornell Medical College; Estados UnidosFil: Antunes Rodrigues, Jose. University Of Ribeirao Preto; BrasilFil: Mecawi , André. Universidade Federal de Sao Paulo.; BrasilFil: Perello, Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Leico Kagohara Elias, Lucila. University Of Ribeirao Preto; BrasilFil: Rorato, Rodrigo. Universidade Federal de Sao Paulo.; Brasi

    Leaf yellowing of the wheat cultivar Mace in the absence of yellowspot disease

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    The wheat variety Mace is currently dominating the southern wheat growing regions of Australia. It is high yielding in most environments and resistant to many diseases including yellow spot (also known as tan spot). However, observations of foliar yellowing of Mace have recently been reported in the field. This has raised concerns over a possible breakdown of resistance to yellow spot, which is caused by the necrotrophic fungal pathogen Pyrenophora triticirepentis. West Australian field samples of yellowing Mace leaves were evaluated for P. triticirepentis infection, and this pathogen was determined to be absent. Instead, Alternaria spp. were isolated from the wheat leaves. Pathogenicity assays showed that the recovered Alternaria spp. were unable to cause disease symptoms on Mace. Furthermore, spontaneous foliar lesions were observed in Mace grown in the absence of pathogens. It is therefore likely that such yellowing is a physiological trait, which will not respond to fungicide application. A marginal impact on yield cannot be excluded

    Low spin spectroscopy of neutron-rich 43,44,45Cl via {\beta} and (\beta}n decay

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    {\beta} decay of neutron-rich isotopes 43,45 S,studied at the National Superconducting Cyclotron Laboratory is reported here. {\beta} delayed {\gamma} transitions were detected by an array of 16 clover detectors surrounding the Beta Counting Station which consists of a 40x40 Double Sided Silicon Strip Detector followed by a Single Sided Silicon Strip Detector. {\beta} decay half-lives have been extracted for 43,45 S by correlating implants and decays in the pixelated implant detector with further coincidence with {\gamma} transitions in the daughter nucleus. The level structure of 43,45 Cl is expanded by the addition of 20 new {\gamma} transitions in 43Cl and 8 in 45 Cl with the observation of core excited negative-parity states for the first time. For 45 S decay, a large fraction of the {\beta} decay strength goes to delayed neutron emission populating states in 44 Cl which are also presented. Comparison of experimental observations is made to detailed shell-model calculations using the SDPFSDG-MU interaction to highlight the role of the diminished N = 28 neutron shell gap and the near degeneracy of the proton s 1/2 and d 3/2 orbitals on the structure of the neutron-rich Cl isotopes. The current work also provides further support to a ground state spin-parity assignment of 3/2 + in 45 Cl

    Vector capabilities in GRASS GIS

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    Vector capabilities in GRASS GIS: an overview of vector topology and its application in network analysi

    Toward enhanced clinical decision support for patients undergoing a hip or knee replacement: focus group and interview study with surgeons

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    Background: The current assessment of recovery after total hip or knee replacement is largely based on the measurement of health outcomes through self-report and clinical observations at follow-up appointments in clinical settings. Home activity-based monitoring may improve assessment of recovery by enabling the collection of more holistic information on a continuous basis. Objective: This study aimed to introduce orthopedic surgeons to time-series analyses of patient activity data generated from a platform of sensors deployed in the homes of patients who have undergone primary total hip or knee replacement and understand the potential role of these data in postoperative clinical decision-making. Methods: Orthopedic surgeons and registrars were recruited through a combination of convenience and snowball sampling. Inclusion criteria were a minimum required experience in total joint replacement surgery specific to the hip or knee or familiarity with postoperative recovery assessment. Exclusion criteria included a lack of specific experience in the field. Of the 9 approached participants, 6 (67%) orthopedic surgeons and 3 (33%) registrars took part in either 1 of 3 focus groups or 1 of 2 interviews. Data were collected using an action-based approach in which stimulus materials (mock data visualizations) provided imaginative and creative interactions with the data. The data were analyzed using a thematic analysis approach. Results: Each data visualization was presented sequentially followed by a discussion of key illustrative commentary from participants, ending with a summary of key themes emerging across the focus group and interview data set. Conclusions: The limitations of the evidence are as follows. The data presented are from 1 English hospital. However, all data reflect the views of surgeons following standard national approaches and training. Although convenience sampling was used, participants’ background, skills, and experience were considered heterogeneous. Passively collected home monitoring data offered a real opportunity to more objectively characterize patients’ recovery from surgery. However, orthopedic surgeons highlighted the considerable difficulty in navigating large amounts of complex data within short medical consultations with patients. Orthopedic surgeons thought that a proposed dashboard presenting information and decision support alerts would fit best with existing clinical workflows. From this, the following guidelines for system design were developed: minimize the risk of misinterpreting data, express a level of confidence in the data, support clinicians in developing relevant skills as time-series data are often unfamiliar, and consider the impact of patient engagement with data in the future
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