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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Depression and Anemia
No full textBackground: Depression exists in mild, moderate, and severe depressive attacks.Evidence suggests that depression is linked to anemia. Several studies have establisheda correlation between depression and anemia. In previous studies, a venous blood samplewas normally used to analyze the average value of hemoglobin and parameters oferythrocytes. The current study examined full blood count (FBC) in different populationsof erythrocytes in individuals with depression (DE) compared to a healthy control group(CON). Material and Methods: All DE, n=24 were diagnosed with DSM-IV and ICD-10. CON,n=54 served as controls. A Percoll™ gradient was used to separate erythrocytes intodifferent density fractions. In all fractions, FBC, i.e., red blood cell count (RBC),hemoglobin concentration (Hb), mean corpuscular hemoglobin (MCH), mean bodyhemoglobin concentration (MCHC) and mean body volume (MCV) were analyzed usinga CELL-DYN 4000. As a comparison, a second blood sample was also taken, where themean values of FBC were analyzed. Results: When the mean value of FBC was analyzed, no significant difference was foundbetween the groups. In contrast, when erythrocytes were separated by density, a lesseramount of Hb was found amongst the smaller erythrocytes, i.e. fractions nos. 8-17 (p <0.05). No significant difference was found when measuring MCH and MCHC in the samedensity fractions. Conclusion: The current study provides evidence that smaller erythrocytes that weredivided by density have less hemoglobin. However, erythrocytes which were notseparated by density i.e. mean values of hemoglobin showed no difference between thegroups. For that reason, it may be of value to perform an extended analysis oferythrocytes and hemoglobin as a complement to the average value of hemoglobin. Thismay be of value when DE patients are investigated for anemia
Platelets : with special reference to platelet density subpopulations, stable coronary heart disease and atrial fibrillation
No full textThe current thesis was divided into two parts. Basic platelet research is the topic of the first section. The subsequent clinical part examines platelet reactivity in stable angina pectoris (AP) and in atrial fibrillation. Platelet heterogeneity was investigated in the first section (papers 1 and 2). The cells were separated according to density using linear Percoll™ (a density medium) gradients. The latter contained EDTA, prostaglandin E1 and theophylline to prevent platelet in vitro activity. The platelet population was then divided into density subpopulations (n = 16 - 20). Membrane attached fibrinogen was determined with a flow cytometer technique and used as a marker reflecting platelet in vivo activity. Platelet P-Selectin content was employed to estimate the quantity of platelet α-granules. Paper I examined healthy blood donors (n = 3). The second report (paper II) compared healthy volunteers (n = 2) and subjects with essential thrombocythemia (ET) (n = 2). The latter is a clonal disease being characterized by an excessive platelet production. Platelet counts were determined in all fractions. In manuscripts I and II determination of surface bound fibrinogen and intracellular P-Selectin was carried out in 12 and 16 platelet density fractions, respectively. High density platelets displayed more surface bound fibrinogen indicating in vivo activity. They also contained less P-Selectin. The latter finding implies platelet in vivo release reactions. Low density platelets circulated with more surface bound fibrinogen as well. Compared with peak density platelets, lighter cells contained more P-Selectin. ET was characterized by a similar platelet density pattern in that high and low density platelets displayed more surface bound fibrinogen. The similarity may explain why severe bleedings do not occur more frequently in ET. It is also obvious from the current thesis that the significance of platelet heterogeneity remains unclear and stimulates to further research. In particular, future work must involve more patients. The second part (papers III-VI) of the thesis was devoted to stable AP and atrial fibrillation. Determination of platelet reactivity i.e. platelet bound fibrinogen after stimulation was carried out in whole blood. A flow cytometer technique was employed (papers III-VI). Adenosine diphosphate (ADP) (1.7 and 8.5 μmol/L) and a thrombin-receptor activating peptide (TRAP-6) (57 and 74 μmol/L) were used as stimulating agents. Determination of peak platelet density (kg/L) was utilized as a further measure reflecting platelet reactivity (paper V). Surface bound and soluble P-Selectin were employed as platelet activity markers (paper VI). Gender differences with respect to platelet reactivity were investigated in paper III. Paper IV examined platelets in stable AP without significant coronary flow obstruction(s) as determined by coronary angiography. In a following study platelet reactivity was analysed in diabetes type II complicated by stable AP (paper V). Finally, long-term (more than 2 years) outcome of atrial fibrillation was related to platelet reactivity and activity (paper VI). In this study the subjects were investigated at the initial electrical cardioversion and the analysis were repeated after more than 2 years. Postmenopausal women with stable AP demonstrated more reactive platelets when stimulating with TRAP-6. They had higher platelet counts (paper III) as well. Stable AP without significant coronary flow obstruction(s) was associated with elevated platelet reactivity (paper IV). Diabetes type II was linked to higher peak platelet density and elevated platelet reactivity (paper V). Augmented platelet reactivity proved to be a feature of subjects remaining in atrial fibrillation more than 2 years after the electrical cardioversion (paper VI). In contrast, the irregular heart rhythm did not affect platelet activity. It is to assume that platelets at least partly are responsible for the sometimes atypical symptoms of females with stable AP. It is also conceivable to speculate that platelets contribute to chest pain in AP free from significant coronary flow obstruction(s). Theoretically, enhanced platelet reactivity could at least partly explain why diabetes type II affects the prognosis of coronary heart disease. The thesis further shows a possible theoretical link between atrial fibrillation, increased platelet reactivity and clot formation
Depression and Anemia
No full textBackground: Depression exists in mild, moderate, and severe depressive attacks.Evidence suggests that depression is linked to anemia. Several studies have establisheda correlation between depression and anemia. In previous studies, a venous blood samplewas normally used to analyze the average value of hemoglobin and parameters oferythrocytes. The current study examined full blood count (FBC) in different populationsof erythrocytes in individuals with depression (DE) compared to a healthy control group(CON). Material and Methods: All DE, n=24 were diagnosed with DSM-IV and ICD-10. CON,n=54 served as controls. A Percoll™ gradient was used to separate erythrocytes intodifferent density fractions. In all fractions, FBC, i.e., red blood cell count (RBC),hemoglobin concentration (Hb), mean corpuscular hemoglobin (MCH), mean bodyhemoglobin concentration (MCHC) and mean body volume (MCV) were analyzed usinga CELL-DYN 4000. As a comparison, a second blood sample was also taken, where themean values of FBC were analyzed. Results: When the mean value of FBC was analyzed, no significant difference was foundbetween the groups. In contrast, when erythrocytes were separated by density, a lesseramount of Hb was found amongst the smaller erythrocytes, i.e. fractions nos. 8-17 (p <0.05). No significant difference was found when measuring MCH and MCHC in the samedensity fractions. Conclusion: The current study provides evidence that smaller erythrocytes that weredivided by density have less hemoglobin. However, erythrocytes which were notseparated by density i.e. mean values of hemoglobin showed no difference between thegroups. For that reason, it may be of value to perform an extended analysis oferythrocytes and hemoglobin as a complement to the average value of hemoglobin. Thismay be of value when DE patients are investigated for anemia
Depression and Anemia [Elektronisk resurs]
No full textBackground: Depression exists in mild, moderate, and severe depressive attacks.Evidence suggests that depression is linked to anemia. Several studies have establisheda correlation between depression and anemia. In previous studies, a venous blood samplewas normally used to analyze the average value of hemoglobin and parameters oferythrocytes. The current study examined full blood count (FBC) in different populationsof erythrocytes in individuals with depression (DE) compared to a healthy control group(CON).Material and Methods: All DE, n=24 were diagnosed with DSM-IV and ICD-10. CON,n=54 served as controls. A Percoll™ gradient was used to separate erythrocytes intodifferent density fractions. In all fractions, FBC, i.e., red blood cell count (RBC),hemoglobin concentration (Hb), mean corpuscular hemoglobin (MCH), mean bodyhemoglobin concentration (MCHC) and mean body volume (MCV) were analyzed usinga CELL-DYN 4000. As a comparison, a second blood sample was also taken, where themean values of FBC were analyzed.Results: When the mean value of FBC was analyzed, no significant difference was foundbetween the groups. In contrast, when erythrocytes were separated by density, a lesseramount of Hb was found amongst the smaller erythrocytes, i.e. fractions nos. 8-17 (p <0.05). No significant difference was found when measuring MCH and MCHC in the samedensity fractions.Conclusion: The current study provides evidence that smaller erythrocytes that weredivided by density have less hemoglobin. However, erythrocytes which were notseparated by density i.e. mean values of hemoglobin showed no difference between thegroups. For that reason, it may be of value to perform an extended analysis oferythrocytes and hemoglobin as a complement to the average value of hemoglobin. Thismay be of value when DE patients are investigated for anemia.</p
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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