1,720,962 research outputs found
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
Vitamin D levels and bone mineral density: are LH levels involved in the pathogenesis of bone impairment in hypogonadal men?
No full textBACKGROUND:
Osteoporosis is a major public health problem also in men and it recognizes hypogonadism as a major cause.
AIMS:
To investigate the possible pathogenetic mechanisms on bone impairment in male hypogonadism and on its improvement in response to testosterone replacement treatment (TRT).
METHODS:
We retrospectively investigated the hormonal profile and bone mineral density (BMD), evaluated by DXA, in 17 middle-aged hypogonadal men treated for at least 5 years with TRT, compared with 21 recently diagnosed untreated hypogonadal males and 18 age- and BMI-matched healthy subjects.
RESULTS:
No significant differences in clinical, biochemical and densitometric parameters were found among the three groups, with the exception of 25-OH vitamin D levels that were significantly higher in healthy subjects compared with hypogonadal patients. Untreated patients affected by central hypogonadism, despite similar hormonal levels, displayed significantly lower BMD and decreased LH and 25-OH vitamin D levels, compared with patients with primary hypogonadism. Among the treated patients, BMD parameters were similar regardless of the formulation of TRT.
CONCLUSIONS:
A recent history of central hypogonadism, compared with primary hypogonadism, appears to adversely affect bone health independently of gonadal steroids levels. This could be due to lower LH levels and consequent reduction of vitamin D 25-hydroxylation in the testis
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
Fracture risk assessment before and after resolution of endogenous hypercortisolism: Is the FRAX(®) algorithm useful?
No full textPurpose Fracture risk data following curative treatment of Cushing's syndrome (CS) are scarce and the role of bisphosphonates in bone recovery after remission is controversial. We evaluated the effects of hypercortisolism remission in bone recovery in CS. Then, we assessed if the FRAX (R) algorithm calculated before the cure can predict fracture risk after cure.
Methods Thirty-six patients with CS were retrospectively investigated. Bone turnover markers, bone mineral density (BMD) at the lumbar spine (L1-L4) and left femur (both neck and total hip were considered), and fracture risk using FRAX (R) algorithm with femoral neck BMD were evaluated at diagnosis and after a median follow-up of 24 months (range 12-108 months) from hypercortisolism remission. Data about bone active therapy were analyzed.
Results Hypercortisolism remission was associated with the improvement of all densitometric parameters and with the reduction of fracture risk. The percentage change in BMD and the fracture risk were not significantly different in bisphosphonate-treated vs. untreated patients. During follow-up, three fractured patients at baseline exhibited a new vertebral fracture. A baseline 10-year probability of major osteoporotic fractures (FRAX (R) Major) of 17 % was able to predict the occurrence of a new vertebral fracture during follow-up after cure with 100 % sensitivity, 77 % specificity, 81 % positive predictive value and 100 % negative predictive value.
Conclusions Osteoporosis and fracture risk may be reversible after curative treatment of CS, regardless of bisphosphonate therapy. We suggest applying the FRAX (R) algorithm to all active CS patients using a baseline FRAX (R) Major of 17 % as "intervention threshold"
Primary aldosteronism and essential hypertension: assessment of cardiovascular risk at diagnosis and after treatment.
No full textBACKGROUND AND AIMS:
Primary aldosteronism (PA), the most frequent form of secondary hypertension, is characterized by a higher rate of cardiovascular (CV) events than essential hypertension (EH). Aim of the study was to evaluate the cardiovascular risk according to the ESH/ESC 2007 guidelines, in patients with PA and with EH, at diagnosis and after treatment.
METHODS AND RESULTS:
We prospectively studied 102 PA patients (40 with aldosterone producing adenoma-APA and 62 with idiopathic hyperaldosteronism-IHA) and 132 essential hypertensives at basal and after surgical or medical treatment (mean follow-up period 44 months for PA and 42 months for EH). At baseline evaluation the stratification of CV risk was significantly different: the predominant risk category was the high CV risk (50% in total PA, 53% in PA matched for blood pressure values and 55% in EH), but the very high risk category was twice in PA than in EH patients (36% in total PA and 33% in matched PA vs. 17% in EH, p < 0.05). The worse risk profile of PA was due to a higher prevalence of glycemic alterations, metabolic syndrome and left ventricular hypertrophy (LVH) (p < 0.05). After adequate treatment, the CV risk was significantly reduced becoming comparable in PA and in EH patient due to a reduction of hypertension grading, prevalence of metabolic syndrome, hypertension persistence and LVH (p < 0.05).
CONCLUSION:
Patients with PA present a high CV risk, which is in part reversible after specific treatment, due both to the reduced blood pressure values and to the improvement of end-organ damage
Asymptomatic primary hyperparathyroidism: surgical and medical management
No full textPrimary hyperparathyroidism (PHPT) is a common endocrine disorder, frequently asymptomatic. Notwithstanding, mild PHPT may cause adverse skeletal effects that include high bone remodeling, reduced bone mineral density (BMD), and increased fracture risk. The definitive therapy for symptomatic and asymptomatic PHPT (aPHPT) is parathyroidectomy, which has been shown to increase BMD. In patients who choose not to be treated surgically or have contraindications for surgery, medical therapy should include drugs designed to protect the skeleton and/or to lower serum calcium, such as bisphosphonates, hormone replacement, and/or calcimimetic agents. However, there are currently no fracture data for any of these options. Obviously, there is the need for larger randomized controlled trials with fractures as end-points to evaluate the efficacy of medical treatment
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