1,721,042 research outputs found
Anterior cingulate activation and error processing during interferon-alpha treatment
No full textBACKGROUND: There has been increasing interest in the role of immunologic processes, notably cytokines, in the development of behavioral alterations, especially in medically ill patients. Interferon (IFN)-alpha is notorious for causing behavioral symptoms, including depression, fatigue, and cognitive dysfunction, and has been used to investigate the effects of cytokines on the brain. METHODS: In the present study we assessed the effects of low-dose IFN-alpha on brain activity, using functional magnetic resonance imaging during a task of visuospatial attention in patients infected with hepatitis C virus (HCV). RESULTS: Despite endorsing symptoms of impaired concentration and fatigue, IFN-alpha-treated patients (n = 10) exhibited task performance and activation of parietal and occipital brain regions similar to that seen in HCV-infected control subjects (n = 11). Interestingly, however, in contrast to control subjects, IFN-alpha-treated patients exhibited significant activation in the dorsal part of the anterior cingulate cortex (ACC), which highly correlated with the number of task-related errors. No such correlation was found in control subjects. CONCLUSIONS: Consistent with the role of the ACC in conflict monitoring, ACC activation during IFN-alpha administration suggests that cytokines might increase processing conflict or reduce the threshold for conflict detection, thereby signaling the need to exert greater mental effort to maintain performance. Such alterations in ACC activity might in turn contribute to cytokine-induced behavioral changes
Basal Ganglia Hypermetabolism and Symptoms of Fatigue during Interferon-alpha Therapy
No full textInterferon (IFN)-alpha is a cytokine of the innate immune response that is well known for inducing behavioral alterations and has been used to study effects of cytokines on the nervous system. Limited data, however, are available on the sites of action of IFN-alpha within the brain and their relationship with specific IFN-alpha-induced symptoms. Using a longitudinal design, whole-brain metabolic activity as assessed by fluorine-18-labeled fluorodeoxyglucose uptake and positron emission tomography was examined before and 4 weeks after IFN-alpha administration in patients with malignant melanoma. Changes in metabolic activity in relevant brain regions were then correlated with IFN-alpha-induced behavioral changes. IFN-alpha administration was associated with widespread bilateral increases in glucose metabolism in subcortical regions including the basal ganglia and cerebellum. Decreases in dorsal prefrontal cortex glucose metabolism were also observed. Prominent IFN-alpha-induced behavioral changes included lassitude, inability to feel, and fatigue. Correlational analyses revealed that self-reported fatigue (specifically as assessed by the 'energy' subscale of the Visual Analog Scale of Fatigue) was associated with increased glucose metabolism in the left nucleus accumbens and putamen. These data indicate that IFN-alpha as well as other cytokines of the innate immune response may target basal ganglia nuclei, thereby contributing to fatigue-related symptoms in medically ill patients
Biochemical and Neuroendocrine Studies in Psychotic and Nonpsychotic Depressions
No full textRothschild AJ, Schatzberg AF. Biochemical and neuroendocrine studies in psychotic and nonpsychotic depressions. In: Schatzberg AF, Nemeroff CB, eds. The hypothalamic pituitary adrenal axis: Physiology, pathophysiology, and psychiatric implications. New York: Raven Press, 1988:187-200
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
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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