170,647 research outputs found
Convective–reactive nucleosynthesis of K, Sc, Cl and p-process isotopes in O–C shell mergers
Get PDF© 2017 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. We address the deficiency of odd-Z elements P, Cl, K and Sc in Galactic chemical evolution models through an investigation of the nucleosynthesis of interacting convective O and C shells in massive stars. 3D hydrodynamic simulations of O-shell convection with moderate C-ingestion rates show no dramatic deviation from spherical symmetry. We derive a spherically averaged diffusion coefficient for 1D nucleosynthesis simulations, which show that such convective-reactive ingestion events can be a production site for P, Cl, K and Sc. An entrainment rate of 10-3M⊙s-1features overproduction factors OPs≈ 7. Full O-C shell mergers in our 1D stellar evolution massive star models have overproduction factors OPm> 1 dex but for such cases 3D hydrodynamic simulations suggest deviations from spherical symmetry. γ - process species can be produced with overproduction factors of OPm> 1 dex, for example, for130, 132Ba. Using the uncertain prediction of the 15M⊙, Z = 0.02 massive star model (OPm≈ 15) as representative for merger or entrainment convective-reactive events involving O- and C-burning shells, and assume that such events occur in more than 50 per cent of all stars, our chemical evolution models reproduce the observed Galactic trends of the odd-Z elements
Omai, Otaitiano condotto in Inghilterra [picture] /
No full textAfter pl. no. LVII, v.1, of: A voyage towards the South Pole and round the world, by J. Caldwall after William Hodges.; Exhibited:'Cook & Omai: The Cult of the South Seas', NLA 2001; Rex Nan Kivell Collection NK11277.; U3045
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
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
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
Eles não disseram tudo: por um suplemento do suplemento de Ana Cristina Cesar em Carlos Drummond de Andrade
Get PDFDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão. Programa de Pós-Graduação em LiteraturaA dissertação que aqui se apresenta consta da análise de comentários feitos por Ana Cristina Cesar às bordas de seu exemplar do livro Reunião, de Carlos Drummond de Andrade. A intenção foi trabalhar as marginálias a partir de uma lógica do suplemento derridiano em um esforço de determinação que pretendeu voltar sempre para a poesia, especialmente de Ana C.. O procedimento se justifica como método escolhido para possibilitar uma abertura das escrituras pelo atrito e em direção oposta àquilo que se identificaria como influência do cânone. Alguns pressupostos teóricos foram estabelecidos para que se pudesse minimamente (e no que concerne a uma dissertação de mestrado) "dar conta" do trabalho, sem pretensões de esvaziar o objeto; esta pesquisa continua (e permanecerá) aberta a novas significações.La dissertation ici présentée comprend une analyse des commentaires faits par Ana Cristina Cesar à propos de son exemplaire du livre Reunião, de Carlos Drummond de Andrade. La démarche a été de travailler les aspects marginaux à partir d'une logique du supplément derridien dans un effort de détermination qui a toujours prétendu revenir à la poésie, surtout celle de Ana C. La procédure se justifie comme méthode choisie car celle-là permet une ouverture des écritures par la confrontation et en direction opposée à ce qui pourrait être identifié comme une influence du canon. Certains concepts théoriques préalables ont été établis pour rendre minimalement possible (en ce qui concerne une dissertation de master) "une procédure complète"; sans prétention de vider l'objet ; cette recherche continue (et perdurera) ouverte à des nouvelles significations
Hypertrophic donavanosis in a young pregnant woman
No full textBACKGROUND:
Donovanosis is a chronic bacterial illness, progressive and indolent, which normally attacks the skin and mucous membranes in the genital and perigenital regions.
CASE:
An 18-year-old pregnant female presented with large, hypertrophic lesions in the ano-genital region. HIV serology was negative. Pap smear revealed a CIN 1 associated with HPV infection. Biopsy yielded macrophages laden with Gram-negative Donovan bodies.
SUMMARY AND CONCLUSION:
A diagnosis of vulvar and perianal donovanosis was reached; the patient decided to terminate the pregnancy and was treated with azithromycin, which led to clinical resolution
Gene Expression Analysis in Human Fetal Endothelial Cells in Physiological Pregnancy and in Intra-Uterine Growth Restriction (IUGR)
No full textHigher mitochondrial dna content in human IUGR placenta
No full textIUGR has been associated to a specific placental phenotype with reduced uptake of specific nutrients. Recently, it has been hypothesized that IUGR may be determined during early gestation. This period is characterized by decidual trophoblast invasion and by intense cellular growth, replication and differentiation. Since a huge energetic availability is required during gestation, we hypothesize that mitochondria may play a crucial role in this process being the main energetic producer in the cell. The aim of this study was to investigate the role of mitochondria in IUGR pathogenesis, evaluating the number of mitochondrial DNA copies (mtDNA) in IUGR placentae compared to controls. Placental samples were collected from 50 singleton pregnancies at the time of elective caesarean section. Twenty-six pregnancies were controls with normal intrauterine growth (AGA) and 24 were studied after the in utero diagnosis of IUGR. All samples were analyzed by real-time quantitative PCR and statistical analysis was performed by non-parametric tests. The median value of mitochondrial DNA content (IQR) in AGA and IUGR placentae was significantly different (455 and 698, respectively, p = 0.004). The cell types responsible for the difference observed is unknown and it is possible that changes observed in the proportion of cell types may influence this measurement. Moreover, a significant negative relationship was observed between mtDNA and umbilical venous pO2, with the highest levels detected in the most severe IUGR cases according to Doppler findings and to the presence of preeclampsia. These data suggest a relationship between the pathogenesis of IUGR and increased placental mtDNA copies. From our results we can speculate that increased mtDNA represents an adaptation of the metabolic placental mechanism to the calorie restriction of the fetus. Furthermore, we found that this rise was inversely related to oxygen tension in the umbilical vein. Although no specific pathogenetic role can be implied, mtDNA increases with hypoxia in placentas of IUGR
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
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