1,720,966 research outputs found
Studio comparativo sullo sviluppo dell'Organo Adiposo nell'uomo e nel topo. Potenziali correlazioni morfo-funzionali
Full text linkI tessuti principali che costituiscono l’organo adiposo sono due: il tessuto adiposo bianco (WAT) e il tessuto adiposo bruno (BAT). Essi sono costituiti da cellule assai differenti per caratteristiche morfologiche, biochimiche e funzionali; tuttavia sono entrambi presenti nello stesso organo all’interno del quale cooperano funzionalmente per il mantenimento dell’omeostasi energetica. Si trovano inoltre zone miste nelle quali si è identificato un terzo tipo cellulare chiamato pauciloculare o brite/beige. Gli adipociti in questione presentano caratteristiche morfologiche e funzionali intermedie tra i tipici adipociti bianchi e quelli bruni, risultando scarsamente positivi per l’UCP1 e con una morfologia multiloculare ma con una goccia lipidica prevalente nel citoplasma.
Il presente studio ha lo scopo di caratterizzare i modelli di sviluppo del BAT e del WAT in specifiche sedi anatomiche, confrontando i depositi di grasso umano fetali con gli stessi dei soggetti umani adulti. A tal fine sono stati analizzati diversi depositi in sedi anatomiche dei compartimenti sottocutanei e viscerali prelevati in 12 soggetti umani durante lo sviluppo fetale (da 16 fino a 39 settimane) utilizzando tecniche di immunoistologia e la TEM. I primi accumuli lipidici si riscontrano nelle isole vascolo-adipocitiche localizzate nella parte superiore del tronco a livello sottocutaneo. In particolare abbiamo studiato il deposito cervicale che mostra una struttura a strati dove la stragrande maggioranza degli adipociti presenti nei livelli superficiali così come in quelli profondi, è caratterizzata da un chiaro aspetto multiloculare e UCP1-positivo. Anche il deposito interscapolare di BAT è visualizzabile in fasi precosi di sviluppo e comunque prima degli accumuli di grasso viscerale presi in esame come il peri-renale ed il para-aortico (mediastinico). In tutti i depositi analizzati, le fibre adrenergiche appaiono nelle isole adipocitiche solo nella fase finale dello sviluppo e solo dopo l’espressione della proteina UCP1. Nei depositi presi in considerazione, in corrispondenza di diversi momenti dello sviluppo, è stato testato lo Zic1, un marker del fenotipo bruno. I risultati suggeriscono che la conversione fenotipica e/o altri meccanismi possono guidare il "whitening” di alcuni depositi, che porta alla scomparsa del BAT negli esseri umani adulti. Scoprire i meccanismi coinvolti nel reclutamento degli adipociti bruni / Brite e il loro mantenimento negli esseri umani adulti avrebbe il potenziale per ispirare strategie terapeutiche che aumentano la spesa energetica nonché per frenare l'obesità e le malattie metaboliche.The main tissues forming the parenchyma of the Adipose Organ are White Adipose Tissue (WAT) and Brown Adipose Tissue (BAT). Both white and brown adipocytes are found together at discrete anatomical locations and they cooperate functionally to maintain energy homeostasis. The multilocular UCP1-positive adipocytes that are interspersed among white adipocytes, are also known as brite or beige adipocytes. This study aims to characterize developmental patterns of BAT and WAT in specific anatomical locations by comparing fetal and adult human fat depots. Several anatomical locations of the subcutaneous and visceral compartments were evaluated in 12 human subjects during fetal development (from 16 up to 39 weeks) using immunohistology and TEM. Lipid accumulation was first detected in the vasculo-adipocytic anlages in the upper portion of the subcutaneous area. In particular, the cervical depot had a layered structure where the vast majority of adipocytes in deep as well as superficial layers, had a clear multilocular UCP1-positive aspects. Interscapular BAT was also detected quite early in development before the accumulation of the visceral fat depots such as the peri-renal and the mediastinal (para-aortic) fat. IN all the depots analyzed, adrenergic fibers appeared in the fat anlages only in the final stage of development and after UCP1 protein expression. Zic1, used as brown adipocyte marker, have been tested in different depots and at different time points of development. Findings suggest that phenotypic conversion and/or other mechanisms may drive the “whitening” of some depots, leading to BAT disappearance in adult humans. Uncovering the mechanisms involved in brown/brite adipocyte recruitment and maintenance in adult humans, would have the potential to inspire therapeutic strategies that increase energy expenditure and to curb obesity and metabolic diseases
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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