1,720,960 research outputs found
The 'Gastrocnemius-Achilles Tendon-Calcaneus complex': Different responses after percutaneous versus vulpius achilles tendon lengthening in New Zealand white rabbits
No full textBackground: This study aimed to describe the clinical, radiological, biomechanical, electromyographic, and histoenzymologic modifications in the 'Gastrocnemius-Achilles Tendon-Calcaneus complex' caused by percutaneous Achilles tendon lengthening (PATL) versus Vulpius Achilles tendon lengthening (VATL) in New Zealand White (NZW) rabbits. Materials and Methods: Eight female NZW rabbits were used at 7 months of age. Two rabbits were euthanized before surgery for anatomical dissection, three underwent PATL (two bilateral and one unilateral), and the three others underwent VATL (two bilateral and one unilateral). Clinical examination, biomechanics, electromyography, standard radiographs and magnetic resonance imaging (MRI), and histology and histoenzymology were assessed after surgery. Results: At the end of the experiment, the subjects showed good clinical status but different functional outcomes of surgery: rabbits submitted to PATL developed permanent limp and lost their capacity to jump compared to rabbits submitted to VATL which remained able to ambulate and jump normally. Standard radiographs and MRI showed that PATL led to significantly greater increase in dorsal or anterior flexion of the tibiotarsal angle (TT angle) compared to VATL, whereas electromyographic and histoenzymologic observations of muscle unit showed little or no variation between the two groups of operated rabbits. Conclusions: Although PATL leads to greater improvement in dorsal or anterior flexion (TT angle) of the rabbit ankle compared to VATL, it has negative effects on functional outcome as it reduces the contractile capacity of the rabbit muscle unit, ultimately impairing the ability to ambulate and jump
Effect of thoracic arthrodesis in prepubertal New Zealand white rabbits on cardio-pulmonary function
No full textBackground: This experimental study was aimed at evaluating the type of cardiac and pulmonary involvement, in relation to changes of the thoracic spine and cage in prepubertal rabbits with nondeformed spine following dorsal arthrodesis. The hypothesis was that T1-T12 arthrodesis modified thoracic dimensions, but would not modify cardiopulmonary function once skeletal maturity was reached. Materials and Methods: The study was conducted in 16 female New Zealand White (NZW) rabbits. Nine rabbits were subjected to T1-T12 dorsal arthrodesis while seven were sham-operated. Echocardiographic images were obtained at 12 months after surgery and parameters for 2-dimensional and M-mode echocardiographic variables were assessed. One week before echocardiographic examination, blood samples were withdrawn from the animals' central artery of the left ear to obtain blood gas values. One week after echocardiographic assessment, a thoracic CT scan was performed under general anesthesia. Chest depth (CD) and width (CW), thoracic kyphosis (ThK) and sternal length (StL) were measured; thoracic index (ThI), expressed as CD/CW ratio. All subjects were euthanized after the CT scan. Heart and lungs were subsequently removed to measure weight and volume. Results: The values for 2-dimensional and M-mode echocardiographic variables were found to be uniformly and significantly higher, compared to those reported in anesthetized rabbits. CD, ThK, and StL were considerably lower in operated rabbits, as compared to the ones that were sham-operated. Similarly, the ThI was lower in operated rabbits than in sham-operated ones. Conclusion: Irregularities in thoracic cage growth resulting from thoracic spine arthrodesis did not alter blood and echocardiographic parameters in NZW rabbits
Radiologic and histological observations in experimental T1-T12 dorsal arthrodesis: A qualitative description of T1-T12 segment and other body parts involved, between prepubertal age and skeletal maturityxs
No full textBackground: This experimental study provides a qualitative description and the morpho-structural features of the fusions taking place in the thoracic spine between prepubertal age and skeletal maturity. There is a lack of informations regarding the influence of partial or total dorso-thoracic vertebral arthrodesis on the development of the thoracic cage as well as its potential effects on different intra and extra-thoracic organs. This study admits the hypothesis that vertebral arthrodesis may have influence on other body areas and so, it intends to verify the possible secondary involvement of other body parts, such as intervertebral discs, cervical and thoracic spinal ganglia, sternocostal cartilage, ovaries and lungs. Materials and Methods: Fifty-four female New Zealand white rabbits were submitted to dorsal arthrodesis. The radiologic imaging and light microscopy histological pictures were taken and studied in all. Computed tomography (CT) scan measurements were performed in operated and sham operated rabbits at different time. Similarly, histological specimens of intervertebral discs, cervical and thoracic spinal ganglia, sternocostal cartilage, ovaries and lungs were analyzed at different times. The study ended at the age of 17-18 months. Results: Most rabbits had formed a fusion mass, which was only fibrous at first, then osteofibrous and finally, in the older subjects, structured in lamellar-osteon tissue. Intervertebral foramens were negatively involved in vertebral arthrodesis, as shown by CT scans. Intervertebral discs showed irregular aspects. The increase of atresic follicles and the reduction of primordial follicles in operated rabbits led to the hypothesis of a cause-effect relationship between arthrodesis and modified hormonal status. Dorsal root ganglia showed microscopic alterations in operated rabbits especially. Conclusions: The process of fusion mass and bone formation, associated with the arthrodesis, involves at different degrees of the vertebral bodies, discs and intervertebral foramens, ganglia and spinal nerve roots. © 2016 Indian Journal of Orthopaedics | Published by Wolters Kluwer - Medknow
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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