1,720,965 research outputs found
Bone and Body Composition by Dual-Energy X-ray Absorptiometry Across a Spectrum: From Precocious to Physiological Puberty
No full textBackground: In recent years, a rising incidence of central precocious puberty (CPP) has been reported, with a notable increase during the COVID-19 pandemic. The onset of puberty is influenced by a multifactorial interplay of genetic, nutritional, environmental, and psychosocial factors. Since puberty is marked by significant changes in body composition and bone mineral accrual, dual-energy X-ray absorptiometry (DXA) represents a valuable tool for accurately assessing fat and lean mass distribution, as well as skeletal development, offering more detailed insights than conventional anthropometric measures.
Aim: To evaluate the clinical, auxological, metabolic, and densitometric characteristics of girls with early pubertal development and to explore potential associations with lifestyle factors and body composition.
Methods: We conducted a retrospective, single-center study including 184 girls with early breast development (before age 9), referred for suspected precocious puberty between 2011 and 2024. Girls were categorized as having central precocious or early puberty (Group P, n=108) or premature thelarche (Group T, n=76), and were compared with age-matched prepubertal controls (Group C, n=47). Data collection included anthropometric measurements, hormonal and metabolic profiles, pelvic ultrasound, and whole-body DXA scans for the assessment of both body composition and bone mineral status. Participants also completed standardized lifestyle questionnaires (KIDMED, PAQ-C, SDSC, and screen time).
Results: Compared to Group T, girls in Group P showed significantly higher delta height-target heigh (ΔH-TH) SDS (p = 0.005), bone age, IGF-1 SDS (adjusted for both chronological and bone age), and uterine dimensions (p < 0.001). In contrast, Group T exhibited significantly higher height SDS, weight, BMI SDS, ΔH-TH SDS (p < 0.05), and IGF-1 SDS (adjusted for both chronological and bone age) compared to Group C (p < 0.001). Additionally, girls in Group P had a significantly lower android-to-gynoid fat ratio and greater total free fat mass than those in Group T (p < 0.05). Compared to controls, girls in Group T showed significantly increased fat and lean mass, as well as higher BMD Z-scores at both the lumbar spine and total body level (p < 0.05). Within Group T, girls presenting with pubarche as the initial pubertal sign had significantly higher weight and BMI SDS (p < 0.001), greater android and gynoid adiposity, total and free fat mass, limb lean mass, , and lumbar spine BMD Z-score than those with thelarche (p < 0.01). In Group T, pubarche-onset girls showed higher Fat-to-Lean Ratio (p < 0.01), indicating greater metabolic risk than those with thelarche.
Lifestyle data (n=100) showed:
• Low adherence to the Mediterranean diet in 21.7% of Group P and 16.1% of T;
• 46.2% reported low physical activity (no difference between groups P and T);
• 28% had sleep disturbances (no intergroup difference);
• 37.2% exceeded 2 hours/day of screen time, more common in Group P.
Conclusions: Significant differences in anthropometry, IGF-1, bone age, and DXA-derived fat and lean mass were observed between groups. Notably, girls with pubarche as the first pubertal sign showed more adverse body composition profiles.
Lifestyle data highlighted suboptimal diet, reduced physical activity, and excessive screen use as modifiable risk factors. These findings underscore the importance of early identification, lifestyle interventions, and individualized management to mitigate long-term health risks associated with early pubertal development
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Approach to the Pediatric Patient: Central Diabetes Insipidus
No full text: Central diabetes insipidus (CDI) is a complex disorder in which large volumes of dilute urine are excreted due to arginine-vasopressin deficiency, and it is caused by a variety of disorders affecting the hypothalamic-posterior pituitary network. The differential diagnosis is challenging and requires a detailed medical history, physical examination, biochemical approach, imaging studies, and, in some cases, histological confirmation. Magnetic resonance imaging is the gold standard method for evaluating congenital or acquired cerebral and pituitary stalk lesions. Pituitary stalk size at presentation could be normal, but it may change over time, depending on the underlying condition, while other brain areas or organs may become involved during follow-up. Early diagnosis and treatment are crucial to avoid central nervous system damage and germ cell tumor dissemination and to minimize complications of multiple pituitary hormone defects. We provide a practical update on the diagnosis and management of patients with CDI and highlight several pitfalls that may complicate the differential diagnosis of conditions presenting with polyuria and polydipsia. The need for a careful and close follow-up of patients with apparently idiopathic CDI is particularly emphasized because the underlying condition may be recognized over time. The clinical scenario that we outline at the beginning of this article represents the basis for the discussion about how the etiological diagnosis of CDI can be overlooked and demonstrates how a water intake and urine output improvement can be a sign of progressive damage of both hypothalamus and anterior pituitary gland with associated pituitary hormonal deficiencies.Central diabetes insipidus (CDI) is a complex disorder in which large volumes of dilute urine are excreted due to arginine-vasopressin deficiency, and it is caused by a variety of disorders affecting the hypothalamic-posterior pituitary network. The differential diagnosis is challenging and requires a detailed medical history, physical examination, biochemical approach, imaging studies, and, in some cases, histological confirmation. Magnetic resonance imaging is the gold standard method for evaluating congenital or acquired cerebral and pituitary stalk lesions. Pituitary stalk size at presentation could be normal, but it may change over time, depending on the underlying condition, while other brain areas or organs may become involved during follow-up. Early diagnosis and treatment are crucial to avoid central nervous system damage and germ cell tumor dissemination and to minimize complications of multiple pituitary hormone defects. We provide a practical update on the diagnosis and management of patients with CDI and highlight several pitfalls that may complicate the differential diagnosis of conditions presenting with polyuria and polydipsia. The need for a careful and close follow-up of patients with apparently idiopathic CDI is particularly emphasized because the underlying condition may be recognized over time. The clinical scenario that we outline at the beginning of this article represents the basis for the discussion about how the etiological diagnosis of CDI can be overlooked and demonstrates how a water intake and urine output improvement can be a sign of progressive damage of both hypothalamus and anterior pituitary gland with associated pituitary hormonal deficiencies
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