1,720,956 research outputs found
Tomographic imaging in companion avian species
Get PDFBackground In the last decades an increasing number of publications, proposing both clinical trials and diagnostic tests, have become available on avian medicine. Despite all the new technical advances the diagnosis and treatment of avian patients is still challenging for the veterinary clinician because birds often display only vague and non-specific symptoms of disease and the investigation of the underlying causes is often very frustrating. In such a scenario diagnostic imaging plays a fundamental role in the clinical evaluation of avian patients. Results The result of this PhD research is an atlas of the tomographic anatomy of three avian species. Most of the clinically relevant structures of the head were visible in both the cross-sections and corresponding CT images. The thin trabeculae characterizing the avian skull were optimally visible on CT images when a standard soft tissue filter and pulmonary window was used. The same CT settings allowed clear visualization of the nostrils, operculum, infraorbital sinus, and cervicocephalic air sacs. The nasal septum, conchae, scleral ossicles, interorbital septum, auditory meatus, and hyoid skeleton were clearly identifiable when a high-resolution filter and bone window were used. Reconstruction of CT images in a dorsal plane enabled a more comprehensive visual examination of some complex structures of the head, such as the diverticula of the infraorbital sinus and the periorbital muscles and glands.
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Structures of the inner ear were not visible in the anatomic cross-sections nor in the CT scans of any of the examined parrot species. A standard soft tissue filter with a soft tissue window allowed a good visibility of the eyes and related structures in all examined species. The cerebral hemispheres, cerebellum, and medulla oblongata were distinguishable only on anatomic cross-sections, and all had the same soft tissue attenuation. All the main organs of the respiratory, digestive, urinary (including the ureters) and reproductive systems were visible both in the anatomical sections and in the corresponding CT images. Conclusions CT is a fast, safe and reliable diagnostic test for avian patients. The possibility to scan the entire body, avoiding the superimposition of the radiography is a great improvement in the diagnostic process. Furthermore, the use of contrast medium allowed optimal visibility of the soft tissues. Those findings suggested that the complex nature of the avian anatomy make CT the diagnostic imaging technique of choice for the evaluation of both the coelomic cavity and the head of avian patients. The matched anatomical cross-sections and CT images presented in this study are a useful reference for the interpretation of CT examination of the blue-and-gold macaw, African grey parrot and monk parakeet. This atlas can be used also for the interpretation of CT images obtained in other psittacine species but the clinicians should be aware of the anatomical differences occurring between the species investigated in these studies and the species object of the investigation. For this reason, further studies, including a larger number of both
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psittacine and non-psittacine species are desirable for a more comprehensive description of the CT anatomy of avian patients.Background In the last decades an increasing number of publications, proposing both clinical trials and diagnostic tests, have become available on avian medicine. Despite all the new technical advances the diagnosis and treatment of avian patients is still challenging for the veterinary clinician because birds often display only vague and non-specific symptoms of disease and the investigation of the underlying causes is often very frustrating. In such a scenario diagnostic imaging plays a fundamental role in the clinical evaluation of avian patients. Results The result of this PhD research is an atlas of the tomographic anatomy of three avian species. Most of the clinically relevant structures of the head were visible in both the cross-sections and corresponding CT images. The thin trabeculae characterizing the avian skull were optimally visible on CT images when a standard soft tissue filter and pulmonary window was used. The same CT settings allowed clear visualization of the nostrils, operculum, infraorbital sinus, and cervicocephalic air sacs. The nasal septum, conchae, scleral ossicles, interorbital septum, auditory meatus, and hyoid skeleton were clearly identifiable when a high-resolution filter and bone window were used. Reconstruction of CT images in a dorsal plane enabled a more comprehensive visual examination of some complex structures of the head, such as the diverticula of the infraorbital sinus and the periorbital muscles and glands.
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Structures of the inner ear were not visible in the anatomic cross-sections nor in the CT scans of any of the examined parrot species. A standard soft tissue filter with a soft tissue window allowed a good visibility of the eyes and related structures in all examined species. The cerebral hemispheres, cerebellum, and medulla oblongata were distinguishable only on anatomic cross-sections, and all had the same soft tissue attenuation. All the main organs of the respiratory, digestive, urinary (including the ureters) and reproductive systems were visible both in the anatomical sections and in the corresponding CT images. Conclusions CT is a fast, safe and reliable diagnostic test for avian patients. The possibility to scan the entire body, avoiding the superimposition of the radiography is a great improvement in the diagnostic process. Furthermore, the use of contrast medium allowed optimal visibility of the soft tissues. Those findings suggested that the complex nature of the avian anatomy make CT the diagnostic imaging technique of choice for the evaluation of both the coelomic cavity and the head of avian patients. The matched anatomical cross-sections and CT images presented in this study are a useful reference for the interpretation of CT examination of the blue-and-gold macaw, African grey parrot and monk parakeet. This atlas can be used also for the interpretation of CT images obtained in other psittacine species but the clinicians should be aware of the anatomical differences occurring between the species investigated in these studies and the species object of the investigation. For this reason, further studies, including a larger number of both
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psittacine and non-psittacine species are desirable for a more comprehensive description of the CT anatomy of avian patients
Computed tomographic anatomy of the heads of blue-and-gold macaws (Ara ararauna), African grey parrots (Psittacus erithacus) and monk parakeets (Myopsitta monachus)
No full textNormal computed tomographic features and reference values for the coelomic cavity in pet parrots
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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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