1,720,981 research outputs found
Subjective perception of body sway
No full textOBJECTIVES AND METHOD: The relation between body sway recorded through a
stabilometric platform and the subjective report of steadiness was studied in 20
young and 20 elderly subjects and 20 neuropathic and 20 parkinsonian patients
standing upright. The trials were performed under two stances (feet apart, feet
together) and two visual conditions (eyes open, eyes closed). At the end of each
trial, subjects scored their performance on a scale from 10 (complete steadiness)
to 0 (fall).
RESULTS: In all subjects, independently of the stance conditions, the larger the
body sway the smaller the reported score. The function best fitting this relation
was linear when sway was expressed on a logarithmic scale. The scoring
reproducibility proved high both within and across subjects. Despite the
different body sways and scores recorded under the different visual and postural
conditions (eyes closed>eyes open, feet together>feet apart) in all groups of
subjects and patients, the slopes of the relations between sway and score were
broadly superimposable. In the normal subjects, the scores were slightly higher
during eyes open than eyes closed trials for corresponding body sways. This was
interpreted as a sign of perception of greater stability when vision was allowed.
Parkinsonian patients swayed to a similar extent as normal subjects, and their
scores were accordingly similar, both with eyes open and eyes closed. Neuropathic
patients swayed to a larger extent than normal subjects, and their scores were
matched appropriately. Although the slope of their relation with eyes closed was
not different from that of normal subjects, with eyes open it was steeper and
similar to that with eyes closed, suggesting that these patients did not feel
more stable when they could take advantage of vision.
CONCLUSIONS: The subjective evaluation of body sway, irrespective of stance
condition, age, neuropathy, and basal ganglia disease, reflects the actual sway,
and is inversely proportional to the logarithm of the sway value. The remarkable
similarity of the relation between score and sway across the various groups of
subjects with eyes closed indicates a common mode of sway evaluation, possibly
based on integration of several sensory inputs. All groups except neuropathic
patients seem to take advantage of the redundancy of the inputs. Basal ganglia
integrity does not seem to have a role in the evaluation of sway
Technical-economic analysis of processes for the production of levulinic acid
Full text linkNowadays most of energy supply and chemicals are produced from fossil fuels. However, environmental concerns like global warming, depletion of non-renewable resources and pollution, force to search for more sustainable alternative feedstocks. In this framework, the valorization of renewable resources is currently one of the most promising strategies for the next future. In particular, the use of biomass is ranked first for production of chemicals. One of the most attractive compounds that can be obtained from lignocellulosic biomass is Levulinic acid (LA). The present work analyses, from a technical, economic and safety standpoint, the valorization of waste biomass (OPEFB, oil palm empty fruit bunch) to LA with different methodologies. Energy demand of the plant and the separation efficiency are evaluated carrying out process simulations by the commercial software Aspen HYSYS V10. The obtained results allowed an economic analysis of the alternatives, based on the evaluation of investment and main operating costs. The alternatives were screened on the basis of net present value (NPV) of costs. Safety performance was investigated by an inherent safety assessment method. This considered toxic dispersion and fire scenarios, calculating the damage distances associated with the potential outcomes of an accident and allowing for the evaluation of a potential hazard index for each main process equipment. The choice of the optimal layout configuration for the production of LA in early phases of design allowed to address, in a time and cost-effective way, further design activities in reducing the energy demand and ensuring potentially safer plants making the whole process more sustainable
Human stance stability improves with the repetition of the task: effect of foot position and visual condition
No full textThe effects of repetition of quiet stance trials on body sway, recorded through a
stabilometric platform, were studied in 12 normal subjects. With feet together,
both with eyes open (EO) and closed (EC), a progressive shift forward of the
centre of foot pressure (CFP) occurred with repetition. In addition, with EC, but
not with EO, a significant progressive reduction in sway area (SA) and sway path
(SP) occurred. With feet 10 cm apart, initial SA and SP values were significantly
smaller than with feet together, regardless of the visual condition, but
repetition of trials induced no significant effects on either position of CFP or
body sway under either visual condition. Results indicate the occurrence of a
learning phenomenon in this simple postural task, whereby the body shifts towards
a 'safer' position with a minimum energy expenditure due to reduced corrections
of sway. Forward leaning and decrease in sway are two independently-occurring
processes, each possibly due to a better central integration of proprioceptive
input with repetition of trials
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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