1,720,953 research outputs found
Imaging genetic risk and episodic memory in psychosis
Get PDFA key feature of many psychiatric disorders, including schizophrenia and bipolar disorder,
are pervasive deficits in several domains of cognition. Episodic memory is one of the most
consistently observed cognitive deficits exhibited by patients with schizophrenia, and can
be a predictor of overall functional outcome. Several neuroimaging studies have assessed
episodic memory in psychosis, however the neural mechanisms underlying this deficit
remain somewhat unclear. Studying the impact of rare genetic variants of large effect can
offer a powerful method to further our understanding of the pathophysiology of psychiatric
disorders. One such gene, DISC1 (Disrupted in Schizophrenia 1) is a putative susceptibility
gene for a spectrum of major psychiatric disorders such as schizophrenia, bipolar disorder
and major depression. DISC1 was originally identified in a large Scottish pedigree, in
which it is disrupted by a balanced translocation between chromosomes 1 and 11, and this
translocation confers a dramatically increased risk of major psychiatric disorder. However,
the impact of this translocation on brain imaging measures is largely unknown. The rarity
of this variation results in small group numbers for analysis, however rare variants are likely
to have large neural effects. This thesis offers a unique investigation into the effects of the
t(1;11) translocation, by examining fMRI of members of the original Scottish pedigree.
Four groups of participants; 19 family members (8 with the translocation, 11 without), 30
patients with schizophrenia, 11 patients with bipolar disorder and 40 healthy controls
underwent a functional MRI episodic memory encoding and recognition paradigm. Data
processing and statistical analyses were performed using the standard approach in SPM8.
The primary aim of this work was to investigate functional activation during episodic memory in individuals with and without the translocation, to examine the impact of the
t(1;11) translocation. Analyses were also performed to examine differences between
controls and patients with schizophrenia and bipolar disorder, to compare the effects of the
translocation to the effects of a having a psychotic illness.
During encoding of neutral scenes, translocation carriers showed greater activation of the
left posterior cingulate, right fusiform gyrus and right superior frontal gyrus compared to
non-carriers. During recognition, carriers showed greater activation in the right fusiform
gyrus, left posterior cerebellum, right superior temporal gyrus, left anterior cingulate, right
ventrolateral prefrontal cortex (VLPFC) and right dorsolateral prefrontal cortex (DLPFC).
For both contrasts, no regions were found to be more active in family members without the
translocation when compared to carriers. There were no significant differences between the
groups in terms of their performance or reaction time on encoding and recognition
conditions.
Compared to healthy controls, patients with schizophrenia demonstrated increased
activation during encoding in the inferior parietal lobe bilaterally, and decreased activation
during recognition in a region encompassing the caudate nucleus and anterior cingulate
cortex. Patients with bipolar disorder showed no difference in activation compared to
controls during encoding, and increased activation during recognition in a region
encompassing the caudate and anterior cingulate, extending to the inferior frontal lobe and
insula. There was also a significant difference between patients with schizophrenia and
bipolar disorder during recognition, with patients with bipolar disorder again showing
increased activation in the caudate extending to the anterior cingulate cortex. These findings support previous research suggesting overactivation of fronto-limbic and striatal
structures including the anterior cingulate and caudate in bipolar disorder, with a relative
underactivation in schizophrenia.
This thesis presents the first evidence of functional alterations during episodic memory in
association with the translocation, primarily in fronto-temporal regions. Brain regions that
were over activated in translocation carriers have been shown to be involved in memory
encoding and recognition, and are known to be affected in patients with major psychiatric
disorders and unaffected relatives. Family members with the translocation demonstrated a
more similar pattern of activation during recognition to patients with bipolar disorder
compared to schizophrenia, perhaps due to the fact that most diagnoses in the carriers were
of an affective disorder rather than a schizophrenia-related psychosis. Based on these
findings it can be argued that the translocation has an influence on brain activations in areas
associated with episodic memory processes. These findings begin to provide a better
understanding of the neural effects of the t(1;11) translocation, and highlight the
significance of rare but biologically informative genetic variants in understanding
psychosis
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
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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