1,080 research outputs found

    The effects of a steer assist system on bicycle postural control in real-life safety challenges

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    With aging, the sensory, motor, and central nervous system deficiencies lead to inadequate bicycle postural control in older cyclists. Similarly, variety in riding skills leads to different bicycle postural control strategies. Cycling seems to be an automated task but keeping the bicycle stable at low speed, pedaling, and steering requires continuous physical and cognitive effort, and in long term may lead to fatigue induced by steering and stabilizing the e-bike at low forward speeds especially in older cyclists. E-bikes enables riders to cycle for langer duration and distance by reducing the physical fatigue. There is an increasing societal interest in electric bicycles where in 2021, 26. 73 billion US dollars worldwide have been invested on e-bikes and by 2027 this global market size will increase to 53.53 billion US dollars (Statista). However, with increased numbers of e-bikes, bicycle accidents due to inadequate steering and balance control by older cyclists have increased, which suggests needs for extra safety measures to maintain balance on a bicycle for challenging situation such as facing undesired disturbances or low forward speeds. We developed a prototype steering assist which aims to increase safety and improve the user experience, by reducing the steering effort and enhancing the bicycle postural control (rider-bike balance control). We investigated the potential effectiveness ofthe steering assist technology in real life challenging situations. Our present study should be considered exploratory research to find the potential effectiveness of the steering assist technology in improving the user experience and safety compared to a non-assistive e-bike. The improved bicycle postural control is validated by smaller range, variability, and rate of steering and roll trajectories when the rider is subjected to an unwanted disturbance. Improved bicycle postural control is expected based on the reduced need for compensatory behavior in the presence of assistive technology. Decreased steering effort is expected due to reduced demand for acute steering control in the anticipatory control strategy

    Pharmacologic and clinical evaluation of posaconazole.

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    Posaconazole, a broad-spectrum triazole antifungal agent, is approved for the prevention of invasive aspergillosis and candidiasis in addition to the treatment of oropharyngeal candidiasis. There is evidence of efficacy in the treatment and prevention of rarer, more difficult-to-treat fungal infections. Posaconazole oral suspension solution has shown limitations with respect to fasting state absorption, elevated gastrointestinal pH and increased motility. The newly approved delayed-release oral tablet and intravenous solution formulations provide an attractive treatment option by reducing interpatient variability and providing flexibility in critically ill patients. On the basis of clinical experience and further clinical studies, posaconazole was found to be a valuable pharmaceutical agent for the treatment of life-threatening fungal infections. This review will examine the development history of posaconazole and highlight the most recent advances

    Measuring the Mechanical Properties of Bicycle Tyres to Help Predict and Minimize Wobble for Enhanced Safety

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    Wobble, also known as speed wobble or shimmy, and the hazard it can cause to cyclists, is a well-known behavior of some bicycles. lt is a relatively high-frequency oscillation, 4-10 Hz. of the front fork and wheel assembly about the steering axis, and it can result in loss of control if left unaddressed. The importance of tyre mechanical properties, specifically conering stiffness, to the wobble motion of bicycles has been shown. Some tyres can make a bicycle more likely to wobble, while others can make the same bicycle less likely to wobble. There are only a few facilities in the world, however, capable of measuring these properties of bicycle tyres, and facilities for testing motorcycle and automobile tyres are not designed to work with bicycle wheels and/or are prohibitively expensive to use. We introduce and characterize an inexpensive, table-top device for measuring the necessary mechanical properties of bicycle tyres

    A Tilting Trike with Rider Tuneable Stability and Handling for lmproved Safety

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    The potential advantages of tilting trikes have been tantalizing for years: they can lean like a bike so that they do not have to be low, wide, or slow in turns; and they can keep the rider upright like a trike when stopped or going slow. Implementing this functionality, however, has been somewhat problematic. Many tilting trikes have been built in which the extra wheel only offers some redundant traction, in the case of inconsistent friction with the road surface. Some have been built with a so-called ''tilt-lock', in which the third wheel can also act as a kickstand to hold the trike rigid when stopped. A few tilting trikes have been built with sophisticated sensors, actuators, and control algorithms to assume the proper tilt angle in every situation, and the motorcycle press breathlessly announces the latest patent filings in this area from major motorcycle manufacturers. [from Introduction

    opty: Software for Trajectory Optimization and Parameter Identification Using Direct Collocation

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    opty is a tool for describing and solving trajectory optimization and parameter identification problems based on symbolic descriptions of ordinary differential equations and differential algebraic equations that describe a dynamical system. The motivation for its development resides in the need to solve optimal control problems of biomechanical systems. The target audience is engineers and scientists interested in solving nonlinear optimal control and parameter identification problems with minimal computational overhead

    Impact of the Journey: IS Employee Attitudes and Perceptions as Organizations Climb the CMM Ladder

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    We surveyed 736 IS professionals in organizations at varying levels of the Capability Maturity Model (CMM) to investigate job attitudes and perceptions. Although anecdotal reports and the scant preliminary empirical studies to-date suggest job attitudes and perceptions improve for employees as organizations climb the CMM ladder, we found evidence of a more complex picture. IS workers reported significantly lower professional efficacy and affective commitment in organizations at CMM Level 3 than in organizations at Level 1, and reports of cynicism were higher in organizations at upper levels of the CMM

    Adaptive smartphone-based sensor fusion for estimating competitive rowing kinematic metrics.

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    Competitive rowing highly values boat position and velocity data for real-time feedback during training, racing and post-training analysis. The ubiquity of smartphones with embedded position (GPS) and motion (accelerometer) sensors motivates their possible use in these tasks. In this paper, we investigate the use of two real-time digital filters to achieve highly accurate yet reasonably priced measurements of boat speed and distance traveled. Both filters combine acceleration and location data to estimate boat distance and speed; the first using a complementary frequency response-based filter technique, the second with a Kalman filter formalism that includes adaptive, real-time estimates of effective accelerometer bias. The estimates of distance and speed from both filters were validated and compared with accurate reference data from a differential GPS system with better than 1 cm precision and a 5 Hz update rate, in experiments using two subjects (an experienced club-level rower and an elite rower) in two different boats on a 300 m course. Compared with single channel (smartphone GPS only) measures of distance and speed, the complementary filter improved the accuracy and precision of boat speed, boat distance traveled, and distance per stroke by 44%, 42%, and 73%, respectively, while the Kalman filter improved the accuracy and precision of boat speed, boat distance traveled, and distance per stroke by 48%, 22%, and 82%, respectively. Both filters demonstrate promise as general purpose methods to substantially improve estimates of important rowing performance metrics

    An Elaborate Data Set on Human Gait and the Effect of Mechanical Perturbations

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    Here we share a rich gait data set collected from fifteen subjects walking at three speeds on an instrumented treadmill. Each trial consists of 120 s of normal walking and 480 s of walking while being longitudinally perturbed during each stance phase with pseudo-random fluctuations in the speed of the treadmill belt. A total of approximately 1.5 h of normal walking (\u3e5000 gait cycles) and 6 h of perturbed walking (\u3e20,000 gait cycles) is included in the data set. We provide full body marker trajectories and ground reaction loads in addition to a presentation of processed data that includes gait events, 2D joint angles, angular rates, and joint torques along with the open source software used for the computations. The protocol is described in detail and supported with additional elaborate meta data for each trial. This data can likely be useful for validating or generating mathematical models that are capable of simulating normal periodic gait and non-periodic, perturbed gaits

    Population Pharmacokinetic and Pharmacodynamic Analysis of Buprenorphine for the Treatment of Neonatal Abstinence Syndrome

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    Neonatal abstinence syndrome (NAS) is a condition affecting newborns exposed to an opioid in utero. Symptoms of NAS include excessive crying, poor feeding, and disordered autonomic control. Up to 2/3 of infants will require pharmacologic therapies to reach symptom control. Opioids including morphine and methadone are the current first-line treatments. Buprenorphine is being investigated as a treatment of NAS. The purpose of this analysis was to evaluate the pharmacokinetics (PK) and pharmacodynamics (PD) of BUP in infants with NAS. Poster presented at American Society for Clinical Pharmacology and Therapeutics (ASCPT) 2017 Annual Meeting, March 15-18, 2017 in Washington DC.https://jdc.jefferson.edu/petposters/1004/thumbnail.jp

    Semi-field evaluation of freestanding transfluthrin passive emanators and the BG sentinel trap as a "push-pull control strategy" against Aedes aegypti mosquitoes

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    Spatial repellents that drive mosquitoes away from treated areas, and odour-baited traps, that attract and kill mosquitoes, can be combined and work synergistically in a push-pull system. Push-pull systems have been shown to reduce house entry and outdoor biting rates of malaria vectors and so have the potential to control other outdoor biting mosquitoes such as Aedes aegypti that transmit arboviral diseases. In this study, semi-field experiments were conducted to evaluate whether a push-pull system could be used to reduce bites from Aedes mosquitoes.; The push and pull under investigation consisted of two freestanding transfluthrin passive emanators (FTPE) and a BG sentinel trap (BGS) respectively. The FTPE contained hessian strips treated with 5.25 g of transfluthrin active ingredient. The efficacies of FTPE and BGS alone and in combination were evaluated by human landing catch in a large semi-field system in Tanzania. We also investigated the protection of FTPE over six months. The data were analyzed using generalized linear mixed models with binomial distribution.; Two FTPE had a protective efficacy (PE) of 61.2% (95% confidence interval (CI): 52.2-69.9%) against the human landing of Ae. aegypti. The BGS did not significantly reduce mosquito landings; the PE was 2.1% (95% CI: -2.9-7.2%). The push-pull provided a PE of 64.5% (95% CI: 59.1-69.9%). However, there was no significant difference in the PE between the push-pull and the two FTPE against Ae. aegypti (P = 0.30). The FTPE offered significant protection against Ae. aegypti at month three, with a PE of 46.4% (95% CI: 41.1-51.8%), but not at six months with a PE of 2.2% (95% CI: -9.0-14.0%).; The PE of the FTPE and the full push-pull are similar, indicative that bite prevention is primarily due to the activity of the FTPE. While these results are encouraging for the FTPE, further work is needed for a push-pull system to be recommended for Ae. aegypti control. The three-month protection against Ae. aegypti bites suggests that FTPE would be a useful additional control tool during dengue outbreaks, that does not require regular user compliance
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