1,721,511 research outputs found
Polycystic ovary syndrome as a diabetes risk factor
No full textPolycystic ovary syndrome (PCOS) is a very common disorder, affecting at least 6-8% of women in the reproductive age. Interestingly, a large body of evidence suggests PCOS is also a metabolic disease, with potential increase of cardiovascular risk. Several data indicate that up to 50-70% of PCOS subjects are insulin resistant, and it was hypothesized they may have specific abnormalities responsible for the impairment of insulin action. Insulin resistance is a well established pathogenic factor for type 2 diabetes mellitus. In addition, beta-cell dysfunction has been also reported in these women. Based on these findings, it is not surprising that abnormalities of glucose metabolism are considered a common feature of PCOS and that several scientific societies have identified PCOS as a significant nonmodifiable risk factor for DM. Nevertheless, literature on this issue is still limited. This paper review available evidence on this topic
Insulin resistance and PCOS: chicken or egg?
No full textPCOS is a common and heterogeneous endocrine disorder in women of reproductive age, frequently associated with metabolic abnormalities. It was estimated that about 75% of these subjects have an impairment of insulin action, as measured by gold standard methods. While the relationship between insulin resistance and PCOS is consistently shown by a number of studies, the mechanisms underlying its primary origin still remains an unsolved issue. Insulin resistance and the associated hyperinsulinemia can induce both the endocrine and reproductive traits of PCOS. However, androgen excess, in turn, can impair insulin action, directly and/or through several changes occurring in different tissues. Body fat excess, which is another common feature in these women, can contribute to worsening the whole picture. Nevertheless, insulin resistance may also be found in many normal-weight individuals. Endocrine and metabolic abnormalities can develop in different moments, and probably there is fetal programming of these alterations. However, a number of vicious circles, with bidirectional relationships between androgen excess and insulin resistance, and with the contribution of several other factors, make it extremely difficult to understand where this process really originates. This review summarizes available evidence on this topic, in order to better understand the complex relationships linking hyperandrogenism and impaired insulin action in women with PCOS
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
A new perspective on the irregular satellites of Saturn - II. Dynamical and physical origin
No full textThe origin of the irregular satellites of the giant planets has been long debated since their discovery. Their dynamical features argue against an in situ formation suggesting that they are captured bodies, yet there is no global consensus on the physical process at the basis of their capture. In this paper, we explore the collisional capture scenario, where the actual satellites originated from impacts occurred within Saturn's influence sphere. By modelling the inverse capture problem, we estimated the families of orbits of the possible parent bodies and the specific impulse needed for their capture. The orbits of these putative parent bodies are compared to those of the minor bodies of the outer Solar system to outline their possible region of formation. Finally, we tested the collisional capture hypothesis on Phoebe by taking advantage of the data supplied by Cassini on its major crater, Jason. Our results presented a realistic range of solutions matching the observational and dynamical data
Individual skills and student mobility in Italy: a regional perspective
No full textInvestigating how qualified human capital is spatially redistributed within a country, and what drives such process in the first place, is essential to understand which regions benefit from its concentration in terms of enhanced productivity and potential for growth. Applying structural equations modelling to the Italian National Institute of Statistics’ (ISTAT) Survey on Educational and Professional Paths of Upper Secondary School Graduates 2011, this paper evaluates the relationship between the propensity to experience interregional student mobility and individual skills in Italy. Findings confirm that the positive link between the two holds also controlling for family background and the characteristics of the region of origin
Il ceto imprenditoriale nel primo decennio repubblicano. Anticipazioni su un campione di ricerca
No full textFerratini Tosi F., Grassi G., Legnani M., Maffeis M., Pirzio P., Zancanaro A. Il ceto imprenditoriale nel primo decennio repubblicano. Anticipazioni su un campione di ricerca. In: Mélanges de l'Ecole française de Rome. Moyen-Age, Temps modernes, tome 95, n°2. 1983. pp. 165-181
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