1,028 research outputs found

    Place peripheral : place-based development in rural, island, and remote regions

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    Place Peripheral offers, a compelling overview of rural, island, and remote regional practices the world over, though with a clear focus on the North Atlantic. In this grand sweep, we have sought to effectively counter the dominant paradigm and discourses of development with a re-articulation of place, location, leadership, and identity. We o(er these as key assets or resources, and as the bases for timely strategies that reconceptualize the future of these places, and perhaps in this way assure them of a future. In unabashedly championing place-based development, Place Peripheral offers an opportune counterpoint to the narratives of marginalization, inferiority, victimization, and dependency that often dominate the study of rural and small island development in Canada, the North Atlantic, and beyond. There are other stories to be told.peer-reviewe

    A half-step in quantized conductance for low-density electrons in a quantum wire

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    We investigated the effect due to perpendicular magnetic field on quantum wires where spin-orbit interaction (SOI) of electrons is not neglected. Based on the calculated energy dispersion, the nonlinear ballistic conductance (GG) and electron-diffusion thermoelectric power (SdS_d) are calculated as functions of electron density, temperature and applied bias voltage. A low-temperature half-step feature in GG, which was observed experimentally by Quay et al. [see Nature Physics {\bf 6}, 336 (2010)], as well as a new peak in SdS_d are reproduced here in the low density regime. These phenomena are related to the occurrence of the Zeeman splitting and SOI induced saddle point in the band structure, where the channel chemical potential lies within an anticrossing gap between the saddle point of the lower subband and the bottom of the upper subband. Additionally, side peaks in GG far away from the zero bias for the nonlinear transport, as well as a quadratic bias-voltage dependence of GG near zero voltage, are predicted and discussed.Comment: 7 figure

    Evaluating Small UAS Near Midair Collision Risk Using AeroScope and ADS-B

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    As small unmanned aircraft systems (sUAS) continue to proliferate in the National Airspace System (NAS), near midair collisions are becoming more common. In late 2017, the National Transportation Safety Board released a report detailing the first confirmed midair collision between a sUAS and manned aircraft in the United States. In February 2018, a video of a sUAS maneuvering around a passenger jetliner on approach to a Las Vegas airport went viral on YouTube. Just months later, a helicopter instructor pilot reported performing evasive maneuvers to avoid colliding with a sUAS, resulting in a non-fatal crash. From 2014 to 2018 the Federal Aviation Administration (FAA) recorded 6,117 reports of near encounters between manned and unmanned aircraft within the NAS (Government Accountability Office [GAO], 2018). In their report, the GAO (2018) highlighted the need for additional operational data to aid the FAA’s management of safety risks posed by unmanned aircraft. The purpose of this study was to evaluate aviation interference and safety hazards caused by unmanned aircraft at an airport in Class C airspace. Using a passive RF sUAS detection device known as the AeroScope, the authors collected sUAS operations data for 13 days at Daytona Beach International Airport in Florida. While the study was limited to DJI-manufactured sUAS, the results yielded detailed operational information on 190 sUAS flights that had been conducted during the sampling period. The authors identified several operator behaviors including preferred sUAS models, flight days and times, common operating locations, and operational altitudes. Operational data was compared against published FAA UAS Facility Maps (UASFM) to examine potential risk areas. Additionally, sUAS detections were compared against historical ADS-B information to examine for potential midair collisions, yielding several notable case studies. The authors evaluated the effectiveness of existing geofencing infrastructure and provided recommendations for integration with the Low Altitude Authorization and Notification Capability (LAANC) system. The paper culminates with a proposal for integrating LAANC usage data into existing aviation information sharing infrastructure to improve manned pilot situational awareness of sUAS activity within the NAS

    Case Report: Optimizing Daily Function for People with Below-elbow Limb Deficiency with the SoftHand Pro

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    Background: Innovation in prosthetic devices for adults with upper limb loss is necessary to meet the demand for effective devices to optimize participation in daily activity. We evaluate the SoftHand Pro (SHP) as a terminal device to determine the application of this biologically-inspired prosthetic hand for use for a person with transradial limb deficiency. Method: This case study describes and measures the first use of the SHP by an individual with transradial limb deficiency in their home environment. This paper reports the features and functionality of the SHP prototype and provides recommendations for changes to further optimize function. Results: The participant found the simple mechanics, durability, and ease of use of the SHP to be beneficial. She praised the SHP’s positive impact on quality of life and suggested areas for optimization. Objective assessments of dexterity and function showed improvements. Conclusion: Using a biologically-inspired myoelectric hand provides an opportunity for intuitively controlled grasp of common large and small objects. The simplicity of use and the lightweight, durable design of the SHP has the potential to provide a positive impact on quality of life, and this case study has provided valuable feedback to further improve the hand and enable larger at-home trials

    The SoftHand Pro: Functional evaluation of a novel, flexible, and robust myoelectric prosthesis

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    Roughly one quarter of active upper limb prosthetic technology is rejected by the user, and user surveys have identified key areas requiring improvement: function, comfort, cost, durability, and appearance. Here we present the first systematic, clinical assessment of a novel prosthetic hand, the SoftHand Pro (SHP), in participants with transradial amputation and age-matched, limb-intact participants. The SHP is a robust and functional prosthetic hand that minimizes cost and weight using an underactuated design with a single motor. Participants with limb loss were evaluated on functional clinical measures before and after a 6-8 hour training period with the SHP as well as with their own prosthesis; limb-intact participants were tested only before and after SHP training. Participants with limb loss also evaluated their own prosthesis and the SHP (following training) using subjective questionnaires. Both objective and subjective results were positive and illuminated the strengths and weaknesses of the SHP. In particular, results pre-training show the SHP is easy to use, and significant improvement in the Activities Measure for Upper Limb Amputees in both groups following a 6-8 hour training highlights the ease of learning the unique features of the SHP (median improvement: 4.71 and 3.26 and p = 0.009 and 0.036 for limb loss and limb-intact groups, respectively). Further, we found no difference in performance compared to participant's own commercial devices in several clinical measures and found performance surpassing these devices on two functional tasks, buttoning a shirt and using a cell phone, suggesting a functional prosthetic design. Finally, improvements are needed in the SHP design and/or training in light of poor results in small object manipulation. Taken together, these results show the promise of the SHP, a flexible and adaptive prosthetic hand, and pave a path forward to ensuring higher functionality in future

    Fingerprinting the Cretaceous-Paleogene boundary impact with Zn isotopes

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    Numerous geochemical anomalies exist at the K-Pg boundary that indicate the addition of extraterrestrial materials; however, none fingerprint volatilization, a key process that occurs during large bolide impacts. Stable Zn isotopes are an exceptional indicator of volatility-related processes, where partial vaporization of Zn leaves the residuum enriched in its heavy isotopes. Here, we present Zn isotope data for sedimentary rock layers of the K-Pg boundary, which display heavier Zn isotope compositions and lower Zn concentrations relative to surrounding sedimentary rocks, the carbonate platform at the impact site, and most carbonaceous chondrites. Neither volcanic events nor secondary alteration during weathering and diagenesis can explain the Zn concentration and isotope signatures present. The systematically higher Zn isotope values within the boundary layer sediments provide an isotopic fingerprint of partially evaporated material within the K-Pg boundary layer, thus earmarking Zn volatilization during impact and subsequent ejecta transport associated with an impact at the K-Pg

    The SoftHand Pro: Translation from Robotic Hand to Prosthetic Prototype

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    This work presents the translation from a humanoid robotic hand to a prosthetic prototype and its first evaluation in a set of 9 persons with amputation. The Pisa/IIT SoftHand is an underactuated hand built on the neuroscientific principle of motor synergies enabling it to perform natural, human-like movements and mold around grasped objects with minimal control input. These features motivated the development of the SoftHand Pro, a prosthetic version of the SoftHand built to interface with a prosthetic socket. The results of the preliminary testing of the SoftHand Pro showed it to be a highly functional design with an intuitive control system. Present results warrant further testing to develop the SoftHand Pro

    Retention of mothers and infants in the prevention of mother-to-child transmission of HIV programme is associated with individual and facility-level factors in Rwanda.

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    OBJECTIVES: Investigate levels of retention at specified time periods along the prevention of mother-to-child transmission (PMTCT) cascade among mother-infant pairs as well as individual- and facility-level factors associated with retention. METHODS: A retrospective cohort of HIV-positive pregnant women and their infants attending five health centres from November 2010 to February 2012 in the Option B programme in Rwanda was established. Data were collected from several health registers and patient follow-up files. Additionally, informant interviews were conducted to ascertain health facility characteristics. Generalized estimating equation methods and modelling were utilized to estimate the number of mothers attending each antenatal care visit and assess factors associated with retention. RESULTS: Data from 457 pregnant women and 462 infants were collected at five different health centres (three urban and two rural facilities). Retention at 30 days after registration and retention at 6 weeks, 3, 6, 9 and 12 months post-delivery were analyzed. Based on an analytical sample of 348, we found that 58% of women and 81% of infants were retained in care within the same health facility at 12 months post-delivery, respectively. However, for mother-infant paired mothers, retention at 12 months was 74% and 79% for their infants. Loss to facility occurred early, with 26% to 33% being lost within 30 days post-registration. In a multivariable model retention was associated with being married, adjusted relative risk (ARR): 1.26, (95% confidence intervals: 1.11, 1.43); antiretroviral therapy eligible, ARR: 1.39, (1.12, 1.73) and CD4 count per 50 mm(3), ARR: 1.02, (1.01, 1.03). CONCLUSIONS: These findings demonstrate varying retention levels among mother-infant pairs along the PMTCT cascade in addition to potential determinants of retention to such programmes. Unmarried, apparently healthy, HIV-positive pregnant women need additional support for programme retention. With the significantly increased workload resulting from lifelong antiretroviral treatment for all HIV-positive pregnant women, strategies need to be developed to identify, provide support and trace these women at risk of loss to follow-up. This study provides further evidence for the need for such a targeted supportive approach

    Validity, practical utility, and reliability of the activPAL in preschool children

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    <p>Purpose: With the increasing global prevalence of childhood obesity, it is important to have appropriate measurement tools for investigating factors (e.g. sedentary time) contributing to positive energy balance in early childhood. For pre-school children, single unit monitors such as the activPALTM are promising. However, validation is required as activity patterns differ from adults.</p> <p>Methods: Thirty pre-school children participated in a validation study. Children were videoed for one hour undertaking usual nursery activity while wearing an activPALTM. Video (criterion method) was analyzed on a second-by-second basis to categorise posture and activity. This was compared with the corresponding activPALTM output. In a subsequent sub-study investigating practical utility and reliability, 20 children wore an activPALTM for seven consecutive 24-hour periods.</p> <p>Results: A total of 97,750 seconds of direct observation from 30 children were categorized as sit/lie (46%), stand (35%), walk (16%); with 3% of time in nonsit/lie/upright postures (e.g. crawl/crouch/kneel-up). Sensitivity for the overall total time matched seconds detected as activPALTM ‘sit/lie’ was 86.7%, specificity 97.1%, and positive predictive value (PPV) 96.3%. For individual children, the median (interquartile range) sensitivity for activPALTM sit/lie was 92.8% (76.1-97.4), specificity 97.3% (94.9-99.2), PPV 97.0% (91.5-99.1). The activPALTM underestimated total time spent sitting (mean difference -4.4%, p<0.01), and overestimated time standing (mean difference 7.1%, p<0.01). There was no difference in overall % time categorised as ‘walk’ (p=0.2). The monitors were well tolerated by children during a seven day period of free-living activity. In the reliability study, at least five days of monitoring were required to obtain an intraclass correlation coefficient of ≥0.8 for time spent sit/lie according to activPALTM output.</p> <p>Conclusion: The activPAL had acceptable validity, practical utility, and reliability for the measurement of posture and activity during freeliving activities in pre-school children.</p&gt
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