1,720,962 research outputs found
Do patients with hypospadias and cryptorchidism share a common phenotype? Case-control study of an Italian paediatric population
No full textOBJECTIVE:
A large number of children affected by hypospadias and undescended testis (UDT) are characterized facially by a large forehead with frontal bossing, telecanthus and broad flat nasal bridge. These traits are classically part of the clinical spectrum of the Opitz-GBBB and other syndromes. The aim of this study was to test the hypothesis that the presence of these features in isolated hypospadias and UDT is not correlated with chromosomal anomalies and/or syndromes, but defines a distinct morphology.
PATIENTS AND METHODS:
Two hundred patients affected by isolated hypospadias and 100 presenting with a UDT were evaluated for facial biometric indices. An age-matched group of patients was used as control. The parameters inter-pupillary/inner canthal ratio and glabella-nose tip/nasion distance were then calculated.
RESULTS:
The glabella-nose tip/nasion distance was significantly different between hypospadias and control groups, but was not different between UDT and control groups. There was no difference in inter-pupillary/inner canthal ratio.
CONCLUSION:
Children affected by hypospadias and/or UDT frequently present peculiar phenotypic features making it possible to recognize them 'at first glance'. This association needs to be explained in future studies
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
Environmental, parental and gestational factors that influence the occurrence of hypospadias in male patients.
No full textOBJECTIVE:
Hypospadias is a congenital defect, which affects normal development of the male urogenital external tract. In this malformation, the urethral orifice of the penis is positioned ventrally, thus interfering with normal urination and creating, in some adults, problems during sexual intercourse. Heritability of hypospadias has been shown in some reports, and the abnormality has been associated with the presence of mutations in one of the genes involved in urogenital development. However, even for patients who were born in families with a higher incidence rate of this defect, no evident genetic alteration could be identified in known genes, indicating that the list of loci involved is still incomplete. To further complicate matters, recent reports also underline that epigenetic changes, without any identifiable gene sequence mutation, may be involved in gene function impairment. Therefore, the inheritance of most hypospadias cases is not evident, suggesting that the genetic background is not the only cause of this malformation; indeed, the majority of hypospadias cases are classified as sporadic and idiopathic.
MATERIALS AND METHODS:
Evidence has accumulated highlighting the role of the environment and of its relationships with the genome in the etiology of this abnormality. In particular, the interaction between some chemicals, which are able to mimic endogenous molecules such as sexual hormones - for this reason called endocrine disrupting compounds (EDC) - and specific receptors has been extensively investigated during the pregnancy. Additionally, several articles have shown that parental and gestational factors play a significant role too. Indeed, physiological alterations, such as body weight of the mother and/or of the newborn, mother's diabetes, impaired father fertility, and exposure of one parent to job-related pollutants, show in many cases a direct correlation with hypospadias incidence. The overall prevalence of this condition has been studied in many countries, suggesting that at least in some periods and/or in specific populations there are detectable fluctuations, probably mirroring the different natural environments. However, many articles present data that do not agree with these findings and, consequently, most causes of hypospadias are still highly debated.
RESULTS:
In this review, we summarize the developmental steps involved in urogenital tract formation, with a particular emphasis on the genes that most frequently are associated with this condition, or that are subject to environmental stress, or that may be the targets of hormone-like, exogenous molecules. Then, we make an overview of the identified factors able to impair the function of important genes, even in the absence of their mutations, including those for which contradictory reports have been published. Finally, we propose an explanation of sporadic cases of hypospadias that reconciles these contradictions and suggest some steps for moving forward in the research focused on this condition.
CONCLUSION:
We hypothesize that most patients develop hypospadias because of gene-environment interactions acting on polymorphic genes that, in the absence of environmental stimuli, would otherwise cause no developmental anomaly during urogenital development
Lichen sclerosus of the male genitalia and urethral stricture disease
No full textIntroduction: The true incidence of urethral involvement in patients with genital lichen sclerosus (LS) is unknown. We review the epidemiology and discuss the pathogenesis of LS and urethral stricture diseases. Materials and Methods: During the period 1991-2002, of 925 patients who underwent urethroplasty for anterior urethral stricture, 130 patients (14%) received the diagnosis of LS. In all patients with LS the histology was re-examined to confirm the clinical diagnosis. Retrograde and voiding urethrography was used to establish urethral involvement in the disease. Results: In 106 patients (82%) the histology provided the classical features of LS, and 24 patients (18%) showed some histological variations. In 49 patients (37%) the LS involved the pendolous urethra (meatus-navicularis-penile), and in 53 cases (41%) a panurethral stricture was evident. Conclusions: LS urethral involvement appears to be a much more common and extensive disease than previously reported, and requires particular care in its early diagnosis
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