1,720,967 research outputs found
Defining the onset of prion infection and neurodegeneration in healthy individuals at risk of prion disease
Get PDFHealthy individuals at risk of prion disease are expected to exhibit subclinical prion replication followed by emergence of toxicity, heralding proximity to clinical onset, based on mouse inoculation studies. This silent incubation period, if recapitulated in humans, will be amenable to fluid biomarker discovery which may inform study designs for preventative strategies.
The central output of this thesis revolves around testing a longitudinal biofluid archive assembled from individuals with high lifetime risk of prion disease, including 16 whom subsequently developed inherited prion disease (IPD), using real-time quaking-induced conversion (RT-QuIC) assay and single molecule array platforms. Two distinct biomarker trajectories, depending on speed of clinical evolution, were discerned. CSF RT-QuIC seeding activity was detectable with over three years’ follow-up in asymptomatic E200K (fast IPD) mutation carriers, but with no definable presymptomatic neurodegenerative phase in one converter. In contrast, P102L (slow IPD) mutation carriers showed sequential rises in plasma glial fibrillary acidic protein followed by neurofilament light up to four years pre-conversion; a bespoke P102L RT-QuIC assay was only partially sensitive. Consequently, we propose a new preclinical staging system featuring clinical, seeding and neurodegeneration components, for validation with larger prion at-risk cohorts, and with potential application to other neurodegenerative proteopathies.
Additionally, we tackled uncertainties that exist over disease penetrance for specific at-risk populations, with implications on epidemiological case definition, and study/trial enrolment eligibility. Firstly, we highlighted the clinical resemblance to sporadic CJD, and necessity of autopsy confirmation, in the first definite case of variant CJD in an individual heterozygous at PRNP codon 129, raising concerns over disease surveillance accuracy and ascertainment of population risk. Secondly, we interrogated multiple lines of evidence to resolve ambiguities over the penetrance of rare PRNP variants – T201S and 2-OPRI, resulting in their reclassification as either benign or low-risk variants, thus avoiding erroneous inclusion into primary prevention studies/trials
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
Fabrication of PSS/PDADMAC polyelectrolyte membrane via layer-by-layer (LbL) technique for forward osmosis (FO) application
Get PDFIn this study, FO membrane was fabricated by Layer-by-Layer (LbL) coating technique using Poly (sodium 4-styrene-sulfonate)(PSS) and Poly (diallyl-dimethylammoniumchloride) (PDADMAC) as the active polyelectrolytes. Different concentrations of polyelectrolytes and deposition time of polyelectrolytes were investigated. The success of the coated layer was confirmed using ATR-FTIR and FESEM images. The membrane performance was determined by water flux and reverse solute diffusion (RSD) using pure water and 1.75M Na2SO4 as feed and draw solution, respectively. It was observed that the highest water flux, 6.76 L/m2∙h was recorded at the lowest polyelectrolytes concentration and longer deposition time. Meanwhile, the minimum RSD was achieved by the membrane fabricated at the longest deposition time and highest polyelectrolyte concentration
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
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