1,720,964 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
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
Risk for obstetric complications and schizophrenia
No full textThe goal of this study was to determine whether cases with schizophrenia or related disorders show a history of obstetric complications significantly more often than control subjects and, if so, whether the enhanced risk of a negative pregnancy outcome also extends to the non-schizophrenic offspring of cases. Data based on the obstetric birth case-notes of patients with diagnosed schizophrenia or related disorders were compared to those of normal 'healthy' control subjects; each case/control pair was individually matched by gender, time and parity of birth, maternal age and marital status. Forty-four case/control pairs born in Padova (Italy) between 1964 and 1978 were assessed for prenatal and perinatal complications, including abnormal gestational age or birthweight. No significant differences were observed between cases and control subjects in the general characteristics of birth; gestational age and birthweight in particular were strictly comparable between cases and control subjects. The schizophrenia spectrum patients (75%) were more likely than control subjects (59%) to have experienced at least one definite obstetric complication: odds ratio=2.07 (95% CI: 0.83-5. 15). Cases also suffered more complications per birth than control subjects (average 2:1). In particular, obstetric complications involving a clear damaging potential were seen significantly more often among cases than control subjects: 34% vs. 9%, Fisher's exact test, P=0.008 (odds ratio=5.17, 95% CI: 1.55-17.21). Moreover, severe obstetric complications were noted more often among males (n=13, 41%) than females (n=2, 15%). When any previous pregnancies of the mothers of patients were compared with those of the mothers of control subjects, mothers of cases were seen to have suffered unfavorable pregnancy outcomes significantly more often. In particular mothers of cases were seen to have had more miscarriages (OR=4.66), and pre-term births (OR=2.58) than control subects' mothers. Severe, brain-damaging obstetric complications would seem to be a possible antecedent to a diagnosis of schizophrenia or a related disorder in adulthood. Indeed, some early onset cases may be accounted for by prenatal brain lesions. This enhanced risk of negative pregnancy outcome may be under genetic control, contributing to the persistence of schizophrenia in the general population. The 'healthy' status of control subjects was ascertained indirectly, not by individual assessment of the subjects. The sample size limits the statistical power of calculations
Obstetric complications in patients with depression--a population-based case-control study
No full textBACKGROUND:
To examine whether sufferers of affective disorders are more likely to be subject to obstetric complications than normal healthy people.
METHOD:
Data based on prospectively recorded birth case-notes for patients with a diagnosis of depression (or related disorders) with early onset were compared to those of normal healthy controls, individually matched by gender, time and parity of birth, maternal age and marital status.
RESULTS:
Forty-one case-controls pairs born between 1964 and 1978 were compared. No differences between cases and controls in gestational age or birthweight were significant, though depressive patients on average weighed 200 g less than controls at birth. Patients were more likely than controls to be small for their gestational age (22 vs. 1: chi(2)=4.34, P=0.03). They were significantly more likely than controls to have suffered at least one obstetric complication: 35 (85%) vs. 25 (60%), chi(2)=5.03, P=0.02; or more than one (two on average, as opposed to one on average among controls). No obstetric complication was seen significantly more among cases than controls, apart from bleeding during gestation, which was observed for four cases and no controls. The prevalence of complications with a clear brain damaging potential did not differ significantly between cases and controls: 11 (26%) vs. 8 (19%).
CONCLUSIONS:
A developmental deficit, as indicated by lower birthweight and gestational age, may contribute to the risk of depressive breakdowns and affective disorders in later life. Severe, brain damaging obstetric complications are unlikely to be a significant risk factor for affective disorders, though some early onset cases may be accounted for by prenatal brain lesions. Limitations: Sample size limits statistical power for isolation of a rare, single risk factor
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
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