1,721,003 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
Bone metabolism and vitamin D levels in carbamazepine-treated patients.
No full textTo the Editor:
I read with great interest the paper by Mintzer et al. (1)
about the vitaminDand bone turnover in epileptic patients
receiving carbamazepine (CBZ) or oxcarbazepine (OXC)
and found an increase in bone metabolism with low serum
25-hydroxyvitamin D (25-OHD).
In our experience (2,3), patients treated by CBZ
monotherapy showed a significant increase of bone
turnover: in fact, we found higher values of markers
of bone formation (serum bone alkaline phosphatase,
osteocalcin, and propetides of types I and III procollagen)
and of bone resorption (serum telopeptide of type I collagen
and urineN-telopeptides of type I collagen) in patients
than in controls. These data confirm the results of Mintzer
et al. (1) who demonstrated significant increase in the bone
formation markers. It is possible that these abnormalities
were secondary to induction of hepatic microsomal enzymes.
In contrast with the results of these authors (1),
in our patients we did not find any significant changes in
serum 25-OHD levels.
There is a great debate about whether this increase in
bone turnover is really due to decrease in 25-OHD. The absence
of relationship between serum 25-OHD and serum
concentration of CBZ shows that the increase of bone
turnover can be independent of the effect of this antiepileptic
drug on vitaminDmetabolism, as previously suggested
(4,5). Moreover, very recently, also Pack et al. (6) found
numerous abnormalities in bone turnover markers with
25-OHD normal levels in their CBZ treated patients. Although
biochemical changes in the metabolism of vitamin
D are observed during treatment with CBZ, whether clinically
apparent and/or histological osteomalacia develops
during treatment with the drug is still controversial; in
fact, no difference in bone mineral density between patients
and controls has been reported. Therefore, we do
not agree with the suggestion of Mintzer et al. (1) who
encourage 25-OHD replacement in patients receiving this
drug, because this preventive treatment could not be always
indicated
L'adolescente epilettico: Aspetti ormonali
No full textEpilepsy is one of the most frequent disease in children, particularly in adolescents. Some types of epilepsy begin typically in the peripubertal period and many studies found changes in frequency or features of seizures in adolescents. This is probably related to sex hormone effects on neuronal excitability. Estrogens seem to decrease neuronal electric threshold with proconvulsant effects. On the contrary progesterone seems to have anticonvulsivant action, as well as testosterone. Changes in hormone serum levels that occur during pubertal period are probably related to modifications in seizure features and are involved in some types of epilepsy that begin typically in adolescence
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
Increased oxidative stress in epileptic children treated with valproic acid.
No full textPURPOSE: To determine influence of Valproic Acid (VPA) treatment on oxidative status in non-obese and overweight epileptic children. METHODS: A prospective study was conducted at the Departments of Pediatrics, University of Chieti and Bologna. Thirty-one epileptic children were studied before and after 1 year of therapy with VPA. Also 31 sex-, age- and BMI-matched healthy controls were evaluated. Insulin and glucose serum levels and plasma Vitamin E, Lag phase and Malondialdehyde (MDA) levels were determined. RESULTS: Before the beginning of VPA therapy, insulin and glucose serum values and plasma Vitamin E, Lag phase and MDA levels were normal in all subjects. At the end of follow-up, 11 (35.5%) epileptic patients developed obesity. In obese VPA treated patients, we found lower serum levels of antioxidant (Vitamin E, p<0.001) and higher levels of oxidant markers (MDA, p<0.001; Lag phase, p<0.001) compared to VPA-treated non-obese patients and controls. CONCLUSION: After 1 year of VPA therapy oxidative stress occurs only in overweight children. This increase in the levels of oxidant markers, probably caused by obesity, might contribute to the development of endothelial dysfunction and atherosclerosis later in life
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
Antiepileptic drugs and visual function.
No full textAntiepileptic drugs are known to result in visual disturbances. A number of antiepileptic drugs have recently been reported to result in various abnormalities of vision, particularly deficiencies in visual fields and color vision. Moreover, there has been a marked improvement in the diagnosis and understanding of the pathophysiology of visual disturbance. This review collects evidence for visual adverse effects induced by the older antiepileptic drugs (barbiturates, benzodiazepine, carbamazepine, valproic acid, ethosuximide, and phenytoin) and the newer ones (vigabatrin, topiramate, tiagabine, levetiracetam, lamotrigine, gabapentin, felbamate, and oxcarbazepine)
Comparative analysis of genomic- and EST-SSRs in European plum (Prunus domestica L.): implications for the diversity analysis of polyploids
No full textSimple sequence repeats (SSRs) are among the most useful DNA markers in plant science. The aim of this study was to compare the features and usefulness of genomic SSR (gSSR) and EST-SSRs in European plum (Prunus domestica L.), an economically important, hexaploid stone fruit crop globally cultivated to produce fleshy fruits and derived foodstuff. The analysis of an ample set of morphologically diverse varieties indicated that gSSRs and EST-SSRs provide different estimates of some of the locus-based indicators of diversity. Moreover, the two classes of SSRs gave different, weakly correlated, estimations of distance-based parameters with gSSRs being more powerful for discriminating purposes. The two SSR classes provide complementary information in European plum, making the contribution of EST-SSRs useful not only as non-neutral markers. The differences between SSR classes are discussed considering the neutral and non-neutral evolution, and the polyploidy and asexual propagation of the cultivated tree varieties
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