1,720,967 research outputs found

    Using UHF RFID properties to develop and optimize an upper-limb rehabilitation system

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    Rehabilitation of the upper limb is an important aspect of the therapy for people affected by neuromotor diseases for the recovery of the capability to perform activities of daily living (ADLs). Nonetheless, the costs associated with the administration of rehabilitation therapy and the increasing number of patients highlight the need for new solutions. Technology-based solutions and, in particular, telerehabilitation could strongly impact in this field. In this paper, a new system based on radiofrequency (RF) technology is presented which is able to effectively provide home-based telerehabilitation and extract meaningful information on the therapy execution performance. The technology has been tuned to the needs of the rehabilitation system, optimizing the hardware, the communication protocol and the software control. A methodology for extracting the execution time of the rehabilitation tasks, the distance covered by the patient’s hand in each subtask and the velocity profile is presented. The results show that a highly usable system for the rehabilitation of the upper limb has been developed using the RF technology and that performance metrics can be reliably extracted by the acquired signals

    Kinematic Evidence of Root-to-Shoot Signaling for the Coding of Support Thickness in Pea Plants

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    Plants such as climbers characterized by stems or tendrils need to find a potential support (e.g., pole, stick, other plants or trees) to reach greater light exposure. Since the time when Darwin carried out research on climbing plants, several studies on plants’ searching and attachment behaviors have demonstrated their unique ability to process some features of a support to modulate their movements accordingly. Nevertheless, the strategies underlying this ability have yet to be uncovered. The present research tries to fill this gap by investigating how the interaction between above-(i.e., stems, tendrils, ... ) and below-ground (i.e., the root system) plant organs influences the kinematics of their approach-to-grasp movements. Using three-dimensional (3D) kinematic analysis, we characterized the movements of pea plants (Pisum sativum L.) as they leaned towards supports whose below-and above-ground parts were characterized by different thicknesses (i.e., thin belowthick above-ground, or the opposite). As a control condition, the plants were placed next to supports with the same thickness below and above ground (i.e., either entirely thin or thick). The results suggest that the information regarding below-and above-ground parts of a support appears to be integrated and modulates the reach-to-grasp behavior of the plant. Information about the support conveyed by the root system seems to be particularly important to achieve the end-goal of movement

    On-line control of movement in plants

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    At first glance, plants seem relatively immobile and, unlike animals, unable to interact with the surroundings or escape stressful environments. But, although markedly different from those of animals, movement pervades all aspects of plant behaviour. Here, we focused our investigation on the approaching movement of climbing plants, that is the movement they perform to reach-to-climb a support. In particular, we examined whether climbing plants evolved a motor accuracy mechanism as to improve the precision of their movement and how this eventually differs from animal species. For this purpose, by means of three-dimensional kinematical analysis, we investigated whether climbing plants have the ability to correct online their movement by means of secondary submovements, and if their frequency production is influenced by the difficulty of the task. Results showed, not only that plants correct their movement in flight, but also that they strategically increase the production of secondary submovements when the task requires more precision, exactly as humans do. These findings support the hypothesis that the movement of plants is far cry from being a simple cause-effect mechanism, but rather is appropriately planned, controlled and eventually corrected

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    The Coding of Object Thickness in Plants: When Roots Matter

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    Tendrils are clasping structures used by climbing plants to anchor and support their vines that coil around suitable hosts to achieve the greatest exposure to sunlight. Although recent evidence suggeststhat climbing plants are able to sense the presence of a potential stimulus in the environment and to planthe tendrils’ movements depending on properties such as its thickness, the mechanisms underlyingthickness sensing in climbing plants have yet to be uncovered. The current research set out to use threedimensionalkinematical analysis to investigate if and in what way the root system contributed to thicknesssensing. Experiment 1 was designed to confirm that the movement of the tendrils of pea plants(Pisum sativum L.) is planned and controlled on the basis of stimulus thickness when the stimulus isinserted into the substrate. Experiment 2 was designed to investigate what happens when the stimulus islifted to the ground so as to impede the root system from sensing it. The results confirmed that tendrils’kinematics depend on thickness when the stimulus is available to the root system but not when it isunavailable to it. These findings suggest that the root system plays a pivotal role in sensing the presenceand the thickness of a stimulus and that the information perceived affects the planning and the executionof the climbing plants’ reach-to-grasp movement

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods
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