1,721,011 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
Preeclampsia/eclampsia: the conceptual evolution of a syndrome
No full textPreeclampsia, one of the most enigmatic complications of pregnancy, is considered a pregnancy-specific disorder caused by the placenta and cured only by delivery. This article traces the condition from its origin—once thought to be a disease of the central nervous system, recognized by the occurrence of seizures (ie eclampsia)—to the present time when preeclampsia is conceptualized primarily as a vascular disorder. We review the epidemiologic data that led to the recommendation to use diastolic hypertension and proteinuria as diagnostic criteria, given that their combined presence was associated with an increased risk of fetal death and the birth of small-for-gestational-age neonates. However, preeclampsia is a multi-systemic disorder with protean manifestations, and the condition can be present even in the absence of hypertension and proteinuria. Toxin(s) that gain access to the maternal circulation have been proposed to mediate the clinical manifestations—hence, the term “toxemia of pregnancy,” which was used for several decades. The search for putative toxins has challenged investigators for more than a century, and a growing body of evidence suggests that products of an ischemic or a stressed placenta are responsible for the vascular changes that characterize the syndrome. The discovery that the placenta can produce anti-angiogenic factors, which regulate endothelial cell function and induce intravascular inflammation, has been a major step forward in the understanding of preeclampsia. We view the release of anti-angiogenic factors by the placenta as an adaptive response to improve uterine perfusion by modulating endothelial function and maternal blood pressure. However, this homeostatic response can become maladaptive and lead to the damage of target organs during pregnancy or the postpartum period. Early-onset preeclampsia has many features in common with atherosclerosis, while late-onset disease appears to result from a mismatch of fetal demands and maternal supply: in other words, a metabolic crisis. Preeclampsia, as it is understood today, is essentially vascular dysfunction unmasked, or caused, by pregnancy that results in a multi-systemic disorder. A subset of patients diagnosed with preeclampsia are at greater risk for the subsequent development of hypertension, ischemic heart diseases, heart failure, vascular dementia, and end-stage renal disease. However, these adverse events may be the result of a preexisting vascular pathologic process; it is not known if the occurrence of preeclampsia by itself increases the baseline risk. The understanding of preeclampsia is a healthcare priority
Disseminated intravascular coagulation in obstetric and gynecologic disorders.
No full textDisseminated intravascular coagulation (DIC) is a syndrome characterized by a massive, widespread, and ongoing activation of the coagulation system, secondary to a variety of clinical conditions. Many obstetric complications, such as abruptio placentae, amniotic fluid embolism, endotoxin sepsis, retained dead fetus, post-hemorrhagic shock, hydatidiform mole, and gynecologic malignancies, might trigger DIC. In these gynecologic and obstetric settings, DIC is usually associated with high mortality and morbidity rates. No single laboratory test is sensitive or specific enough to diagnose DIC definitively, but it can be diagnosed by using a combination of multiple clinical and laboratory tests that reflect the pathophysiology of the syndrome. At present, the therapeutical approach to pregnancy- and gynecologic-related DIC comprises the specific and aggressive treatment of the underlying disease, eventually followed by a supportive blood product replacement therapy and restoration of physiological anticoagulant pathways. This article reviews the etiopathogenesis, clinical manifestations, laboratory diagnosis, and therapy of pregnancy- and gynecologic-related DIC. © 2010 by Thieme Medical Publishers, Inc.Disseminated intravascular coagulation (DIC) is a syndrome characterized by a massive, widespread, and ongoing activation of the coagulation system, secondary to a variety of clinical conditions. Many obstetric complications, such as abruptio placentae, amniotic fluid embolism, endotoxin sepsis, retained dead fetus, post-hemorrhagic shock, hydatidiform mole, and gynecologic malignancies, might trigger DIC. In these gynecologic and obstetric settings, DIC is usually associated with high mortality and morbidity rates. No single laboratory test is sensitive or specific enough to diagnose DIC definitively, but it can be diagnosed by using a combination of multiple clinical and laboratory tests that reflect the pathophysiology of the syndrome. At present, the therapeutical approach to pregnancy-and gynecologic-related DIC comprises the specific and aggressive treatment of the underlying disease, eventually followed by a supportive blood product replacement therapy and restoration of physiological anticoagulant pathways. This article reviews the etiopathogenesis, clinical manifestations, laboratory diagnosis, and therapy of pregnancy- and gynecologic-related DIC
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
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