519 research outputs found

    Effects of a selected motor skill task on the development of stereopsis

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    One would expect visual-perceptual abilities to be quite important in sport skills. Donna Mae Miller (1960) substantiated this idea when she examined a battery of eight tests she felt were important in responding quickly and accurately to visual cues. Highly skilled athletes scored considerably higher in areas of static balance, stereopsis, blocks response and mutilated words than did lower skilled athletes. Williams (1968) in a similar study looked at visu&l-perceptual judgments in a more dynamic approach. Subjects were asked to catch tennis balls after they had been projected into the air and bounced off of a canvas. The results found highly skilled performers significantly superior in visual perception to individuals classified as poorly skilled

    Reforming fossil fuel subsidies: drivers, barriers and the state of progress

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    This article outlines the current state of affairs in fossil fuel subsidy reform, and highlights its contribution at the nexus of climate policy, fiscal stability and sustainable development. It discusses common definitions, provides quantitative estimates, and presents the evidence for key arguments in favour of subsidy reform. The main drivers and barriers for reform are also discussed, including the role of (low) oil prices and political economy challenges. Commitments to subsidy reform by the international community are reviewed, as well as the progress at the country level. Although fossil fuel subsidy reform indeed plays a critical role in climate policy, experience shows that the rationale for such reforms is determined in a complex environment of political economy challenges, macro-economic, fiscal and social factors, as well as external drivers such as energy prices. The article synthesizes the key principles for designing effective reforms and emphasizes that subsidy reforms cannot only yield fiscal relief, but should also contribute to long-term sustainable development objectives. Areas for future research are also identified

    Modular and Cooperative Medical Devices and Related Systems and Methods

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    The various embodiments disclosed herein relate to modular medical devices, including various devices with detachable modular components and various devices with pivotally attached modular components. Additional embodiments relate to procedures in which various of the devices are used cooperatively. Certain embodiments of the medical devices are robotic in vivo devices

    Mirror-image relations in category learning

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    The discrimination of patterns that are mirror-symmetric counterparts of each other is difficult and requires substantial training. We explored whether mirror-image discrimination during expertise acquisition is based on associative learning strategies or involves a representational shift towards configural pattern descriptions that permit resolution of symmetry relations. Subjects were trained to discriminate between sets of unfamiliar grey-level patterns in two conditions, which either required the separation of mirror images or not. Both groups were subsequently tested in a 4-class category-learning task employing the same set of stimuli. The results show that subjects who had successfully learned to discriminate between mirror-symmetric counterparts were distinctly faster in the categorization task, indicating a transfer of conceptual knowledge between the two tasks. Additional computer simulations suggest that the development of such symmetry concepts involves the construction of configural, protoholistic descriptions, in which positions of pattern parts are encoded relative to a spatial frame of reference

    METHODS, SYSTEMS, AND DEVICES FOR SURGICAL ACCESS AND PROCEDURES

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    The embodiments disclosed herein relate to various medical device components, including components that can be incorporated into robotic and/or in vivo medical devices. Certain embodiments include various actuation system embodiments, including fluid actuation systems, drive train actuation systems, and motorless actuation systems. Additional embodiments include a reversibly lockable tube that can provide access for a medical device to a patient\u27s cavity and further provides a reversible rigidity or stability during operation of the device. Further embodiments include various operational components for medical devices, including medical device arm mechanisms that have both axial and rotational movement while maintaining a relatively compact structure. medical device winch components, medical device biopsy/stapler/clamp mechanisms, and medical device adjustable focus mechanisms

    Localized electronic states and photoemission superconducting condensate in Bi2_{2}Sr2_{2}Ca1_{1}Cu2_{2}O8+x_{8+x}

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    We present the first detailed angle-resolved photoemission evidence that there are two types of carriers that contribute to the photoemission superconducting condensate in Bi2Sr2Ca1Cu2O8+xBi_{2}Sr_{2}Ca_{1}Cu_{2}O_{8+x}. Our data indicate that both itinerant and somewhat localized normal state carriers can contribute to the formation of Cooper pairs.Comment: APS_Revtex, 11 pages, including 3 figures, available upon request. UW-Madison preprint#

    Wireless Tissue Palpation for Intraoperative Detection of Lumps in the Soft Tissue

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    In an open surgery, identification of precise margins for curative tissue resection is performed by manual palpation. This is not the case for minimally invasive and robotic procedures, where tactile feedback is either distorted or not available. In this paper, we introduce the concept of intraoperative wireless tissue palpation. The wireless palpation probe (WPP) is a cylindrical device (15 mm in diameter, 60 mm in length) that can be deployed through a trocar incision and directly controlled by the surgeon to create a volumetric stiffness distribution map of the region of interest. This map can then be used to guide the tissue resection to minimize healthy tissue loss. The wireless operation prevents the need for a dedicated port and reduces the chance of instrument clashing in the operating field. The WPP is able to measure in real time the indentation pressure with a sensitivity of 34 Pa, the indentation depth with an accuracy of 0.68 mm, and the probe position with a maximum error of 11.3 mm in a tridimensional workspace. The WPP was assessed on the benchtop in detecting the local stiffness of two different silicone tissue simulators (elastic modulus ranging from 45 to 220 kPa), showing a maximum relative error below 5%. Then, in vivo trials were aimed to identify an agar-gel lump injected into a porcine liver and to assess the device usability within the frame of a laparoscopic procedure. The stiffness map created intraoperatively by the WPP was compared with a map generated ex vivo by a standard uniaxial material tester, showing less than 8% local stiffness error at the site of the lump

    In vivo laparoscopic robotics

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    AbstractRobotic laparoscopic surgery is evolving to include in vivo robotic assistants. The impetus for the development of this technology is to provide surgeons with additional viewpoints and unconstrained manipulators that improve safety and reduce patient trauma. A family of these robots have been developed to provide vision and task assistance. Fixed-base and mobile robots have been designed and tested in animal models with much success. A cholecystectomy, prostatectomy, and nephrectomy have all been performed with the assistance of these robots. These early successful tests show how in vivo laparoscopic robotics may be part of the next advancement in surgical technology
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