1,720,963 research outputs found
Validity of ultrasound imaging versus magnetic resonance imaging for measuring anterior thigh muscle, subcutaneous fat, and fascia thickness
No full textThe aim of the present study was to determine the validity of ultrasound (US) imaging versus magnetic resonance imaging (MRI) for measuring anterior thigh muscle, subcutaneous adipose tissue (SAT), and fascia thickness. Twenty healthy, moderately active participants (aged 49.1 ± 9.74 (36–64) years), underwent imaging of the anterior thigh, using ultrasound and MRI modalities on the same day. Images were analyzed offline to assess the level of agreement between US and MRI measurements. Pearson’s correlation coefficient showed an excellent relationship between US imaging and MRI for measuring muscle (r = 0.99, p < 0.01), SAT (r = 0.99, p < 0.01), and non-contractile tissue (SAT combined with perimuscular fascia) thickness (r = 0.99, p < 0.01). Perimuscular fascia thickness measurement showed a poor correlation between modalities (r = 0.39, p < 0.01). Intra-class correlation coefficients (ICC3,1) also showed excellent correlation of the measurements with ICC = 0.99 for muscle thickness, SAT, and non-contractile tissue, but not for perimuscular fascia, which showed poor agreement ICC = 0.36. Bland and Altman plots demonstrated excellent agreement between US imaging and MRI measurements. Criterion validity was demonstrated for US imaging against MRI, for measuring thickness of muscle and SAT, but not perimuscular fascia alone on the anterior thigh. The US imaging technique is therefore applicable for research and clinical purposes for muscle and SAT
Ultrasound imaging for measuring muscle and subcutaneous fat tissue thickness of the anterior thigh: A two-year longitudinal study in middle age
No full textBackground Ultrasound (US) imaging technique is widely used in research and clinical settings to assess the morphology and morphometry of neuromusculoskeletal structures. The technique has reported validity and reliability in measuring the size of various muscles under controlled conditions. The aim of the present study was to assess anterior thigh thickness using US imaging, in a healthy cohort of middle-aged older adults.Methods Participants included seventeen healthy older adults involved in regular moderate-vigorous activities (age range 39-66 years). US imaging scans of the anterior thighs two years since baseline measurements were performed. Images were analyzed off-line to compare US imaging measurements of muscle thickness and subcutaneous fat (SF) of the anterior thigh taken at baseline and after two years.Results There was no significant difference between muscle thickness measurements taken at baseline and after two years (Mean, standard deviation; baseline=2.80±0.71cm; follow-up=2.77±0.72cm, p=0.33). There was also no significant change in SF thickness (baseline=1.04±0.41cm; follow-up=1.06±0.40, p=0.33).Conclusions The results show there was no decline in anterior thigh muscle thickness or increase in SF in the healthy cohort studied using US imaging over a two-year period. These findings demonstrate the robustness of US imaging measurements over time
Inter-rater and intra-rater reliability of ultrasound imaging for measuring quadriceps muscle and non-contractile tissue thickness of the anterior thigh
No full textObjective: To determine intra-rater and inter-rater reliability of ultrasound imaging for measuring muscle and non-contractile (subcutaneous fat and perimuscular fascia) tissue thickness of the anterior thigh. Approach: Ultrasound imaging has been used for clinical research to assess the morphology and cross-sectional area of muscles and other musculoskeletal structures. Repeatability of measurements with the ultrasound imaging technique between operators and test re-test reliability are important and need to be established for specific muscles. Twenty-four healthy moderately active adults (aged 36–64 years), underwent B-mode ultrasound imaging by two investigators. The anterior thighs were scanned at a site two-thirds of the distance between the antero-superior iliac spine and the superior pole of the patella. Intraclass Correlation Coefficients (ICCs, model 3, 1 for inter-rater and 3, 2 for intra-rater reliability between-days) with 95% confidence intervals (CI) was used to assess reliability. Main results: Inter-rater reliability of ultrasound imaging measurements were ICC3, 1 of 0.98 (95% CI: 0.95–0.99) for muscle thickness, 0.81 (95% CI: 0.60–0.91) for subcutaneous fat, 0.78 (95% CI: 0.56–0.90) for non-contractile tissue (subcutaneous fat combined with perimuscular fascia), and 0.70 (95% CI: 0.42–0.86) for perimuscular fascia. Intra-rater reliability values were ICC3, 2 0.96 (95% CI: 0.90–0.98) for muscle thickness, 0.99 (95% CI: 0.97–0.99) for subcutaneous fat, 0.98 (95% CI: 0.96–0.99) for non-contractile tissue, and −0.02 (95% CI: −0.41–0.38) for perimuscular fascia. Significance: The present findings indicate very high inter-rater and intra-rater reliability of ultrasound imaging thickness measurements of the quadriceps muscles and non-contractile tissue of the anterior thigh, while perimuscular fascia measurements alone were not reliable between days
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
Clinical utility of ultrasound imaging for measuring anterior thigh thickness after anterior cruciate ligament injury in an individual patient to assess post-surgery outcome
Full text linkThe present study investigated the clinical utility of ultrasound imaging (USI) for assessing changes in an individual’s quadriceps muscle and subcutaneous fat (SF) thickness of the anterior thigh and their relative proportions. A patient was studied prior to and after anterior cruciate ligament reconstruction (ACLR) surgery and during rehabilitation. This case study involved an 18-year-old female recreational athlete with a complete tear of the anterior cruciate ligament (ACL). Tissue thickness (SF and quadriceps muscle) was measured from transverse USI of the anterior thigh before surgery, at weekly intervals during 12 weeks of postsurgery, and then every 2 weeks for the following 12 weeks (total of 21 measurement sets). Statistically significant differences presurgery to postrehabilitation were found for muscle thickness (p=0.04) and SF tissue thickness (p=0.04) measurements. There was no difference in muscle to fat ratio (p=0.08). Changes in measurements greater than the reported minimal detectable change (MDC) demonstrate the sensitivity of the USI technique as an objective tool to assess clinically useful changes in an individual’s anterior thigh muscle thickness post-ACLR surgery and during rehabilitation
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
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