1,720,989 research outputs found
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
Advanced Glycation End Products: Link between Diet and Ovulatory Dysfunction in PCOS?
No full textPCOS is the most common cause of anovulation in reproductive-aged women with 70% experiencing ovulatory problems. Advanced glycation end products are highly reactive molecules that are formed by non-enzymatic reactions of sugars with proteins, nucleic acids and lipids. AGEs are also present in a variety of diet where substantial increase in AGEs can result due to thermal processing and modifications of food. Elevation in bodily AGEs, produced endogenously or absorbed exogenously from high-AGE diets, is further exaggerated in women with PCOS and is associated with ovulatory dysfunction. Additionally, increased expression of AGEs as pro-inflammatory receptors in the ovarian tissue has been observed in women with PCOS. In this review, we summarize the role of dietary AGEs as mediators of metabolic and reproductive alterations in PCOS. Once a mechanistic understanding of the relationship between AGEs and anovulation is established, there is a promise that such knowledge will contribute to the subsequent development of targeted pharmacological therapies that will treat anovulation and improve ovarian health in women with PCOS
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
Acute Abdominal Pain as the Presenting Symptom of Isolated Iliac Vein Thrombosis in Pregnancy
No full textImpact of dramatic weight loss with the new injectable medications on reproduction in healthy non–polycystic ovary syndrome obese women
No full textThe intake of glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) in obese women with polycystic ovary syndrome (PCOS) demonstrated improvement in metabolic and reproductive symptoms; however, their impact in non-PCOS state is unclear. This review critically analyzes data pertaining to GLP-1 RAs in non-PCOS females in both humans and animals, with a focus on their impact on the hypothalamic-pituitary-ovarian axis and the uterine function. In animal models, studies showed controversial results. The intracerebroventricular GLP-1 administration caused stimulatory reproductive effects, where it increased the amplitude of the luteinizing hormone surge, follicle-stimulating hormone (FSH) secretion, serum progesterone levels, up-regulation in Kiss-1r expression in the hypothalamus, and increase in ovarian Graafian follicles and corpora lutea. However, the intracerebroventricular GLP-1 RA Exendin-4 and the subcutaneous GLP-1 RA liraglutide resulted in opposite effects. Even though GLP-1 up-regulated FSH receptor messenger ribonucleic acid expression in granulosa cells, it led to a suppression in FSH-induced progesterone synthesis. The effect of GLP-1 RA on the uterus also showed controversial findings. Although some data showed that GLP-1 RA had a beneficial antifibrotic effect in intrauterine adhesions model by reducing the deposition area of collagen fibers, other data showed that exposure to GLP-1 RA resulted in destruction of the luminal epithelium with shrinkage in muscle fiber. It is unclear how these GLP-1 RA medications impact future fertility in humans because most studies to date had significant limitations and were performed in animals with contentious findings. There is a clear need to study this relationship because many reproductive-aged women without PCOS are resorting to these medications for weight loss purposes
Relationship between Advanced Glycation End Products and Steroidogenesis in PCOS
No full textAbstract Background Women with PCOS have elevated levels of the harmful Advanced Glycation End Products (AGEs), which are highly reactive molecules formed after glycation of lipids and proteins. Additionally, AGEs accumulate in the ovaries of women with PCOS potentially contributing to the well-documented abnormal steroidogenesis and folliculogenesis. Main body A systematic review of articles and abstracts available in PubMed was conducted and presented in a systemic manner. This article reports changes in steroidogenic enzyme activity in granulosa and theca cells in PCOS and PCOS-models. It also described the changes in AGEs and their receptors in the ovaries of women with PCOS and presents the underlying mechanism(s) whereby AGEs could be responsible for the PCOS-related changes in granulosa and theca cell function thus adversely impacting steroidogenesis and follicular development. AGEs are associated with hyperandrogenism in PCOS possibly by altering the activity of various enzymes such as cholesterol side-chain cleavage enzyme cytochrome P450, steroidogenic acute regulatory protein, 17α-hydroxylase, and 3β-hydroxysteroid dehydrogenase. AGEs also affect luteinizing hormone receptor and anti-Mullerian hormone receptor expression as well as their signaling pathways in granulosa cells. Conclusions A better understanding of how AGEs alter granulosa and theca cell function is likely to contribute meaningfully to a conceptual framework whereby new interventions to prevent and/or treat ovarian dysfunction in PCOS can ultimately be developed
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