170,372 research outputs found
Population balance modelling of bubble columns under the heterogeneous regime
No full textPopulation Balance Modeling Conference 2018 (PBM 2018
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
EMD-Based Filtering Using Similarity Measure Between Probability Density Functions of IMFs
No full textThis paper introduces a new signal-filtering which combines the empirical mode decomposition (EMD) and a similarity measure. A noisy signal is adaptively broken down into oscillatory components called intrinsic mode functions (IMFs) by EMD followed by an estimation of the probability density function (pdf) of each extracted mode. The key idea of this paper is to make use of partial reconstruction, the relevant modes being selected on the basis of a striking similarity between the pdf of the input signal and that of each mode. Different similarity measures are investigated and compared. The obtained results, on simulated and real signals, show the effectiveness of the pdf-based filtering strategy for removing both white Gaussian and colored noises and demonstrate its superior performance over partial reconstruction approaches reported in the literature
Receipt to Priscilla C. Jemison from Roullier-Augier, August 9, 1860
No full textThis item is from the Robert Jemison, Jr. Papers. The collection spans the period from 1797 to 1960 and includes both the personal and business papers of Robert Jemison, Jr., along with papers of Robert Jemison (grandfather), William Jemison (father), Priscilla Jemison (wife), Cherokee Jemison Hargrove (daughter), and Andrew Coleman Hargrove (son-in-law), and Robert Jemison, Jr. (IV) of Birmingham (1878-1973). Included are the records of his grist and lumber mills, plantations, stage line, the Tuskaloosa Plank Road, toll bridges, ferries, postal contracts, and the North East and South West Railroad
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Sapho : opéra en 3 actes. [Paris, Opéra, 16 avril 1851] / par Émile Augier ; musique de Charles Gounod
No full textAvec mode text
Nicotine increases alcohol self-administration in male rats via a μ-opioid mechanism within the mesolimbic pathway
No full textBackground and Purpose: Alcohol and nicotine use disorders are commonly comorbid. Both alcohol and nicotine can activate opioid systems in reward-related brain regions, leading to adaptive changes in opioid signalling upon chronic exposure. The potential role of these adaptations for comorbidity is presently unknown. Here, we examined the contribution of μ and κ-opioid receptors to nicotine-induced escalation of alcohol self-administration in rats. Experimental Approach: Chronic nicotine was tested on alcohol self-administration and motivation to obtain alcohol. We then tested the effect of the κ antagonist CERC-501 and the preferential μ receptor antagonist naltrexone on basal and nicotine-escalated alcohol self-administration. To probe μ or κ receptor adaptations, receptor binding and G-protein coupling assays were performed in reward-related brain regions. Finally, dopaminergic activity in response to alcohol was examined, using phosphorylation of DARPP-32 in nucleus accumbens as a biomarker. Key Results: Nicotine robustly induced escalation of alcohol self-administration and motivation to obtain alcohol. This was blocked by naltrexone but not by CERC-501. Escalation of alcohol self-administration was associated with decreased DAMGO-stimulated μ receptor signalling in the ventral tegmental area (VTA) and decreased pDARPP-32 in the nucleus accumbens shell in response to alcohol. Conclusions and Implications: Collectively, these results suggest that nicotine contributes to escalate alcohol self-administration through a dysregulation of μ receptor activity in the VTA. These data imply that targeting μ rather than κ receptors may be the preferred pharmacotherapeutic approach for the treatment of alcohol use disorder when nicotine use contributes to alcohol consumption
Hydrodynamics and bubble size in bubble columns: Effects of contaminants and spargers
No full textThe simulation of bubble columns operating under the heterogeneous regime is an ambitious challenge, due to the difficulty of predicting accurately hydrodynamics and bubble size distributions, that requires experimental data for model validation. Gas fraction distributions, liquid and gas velocity profiles and bubble size distributions across bubble columns are deeply interconnected in these systems and only a comprehensive study allows the links between them to be understood. This work reports experimental data obtained by measuring bubble sizes with an innovative technique based on the cross correlation between two optical probes. Particular attention is given to the role of additives and impurities with a view to suppressing bubble coalescence. Initially experiments are carried out with demineralized water; subsequently they are repeated with tap water and adding small quantities of ethanol. Results show that contaminants and alcohol addition suppress bubble coalescence and induces a decrease of mean bubble sizes. Furthermore, alcohol addition delays the transition from homogeneous to heterogeneous regimes and increases the gas hold-up under the heterogeneous regime. Gas distribution is studied through two different perforated spargers. Changing the sparger it is possible to modify the bubble size in the lowest part of the column significantly. A perforated sparger with big holes causes the formation of big bubbles close to the holes of the sparger and promotes bubble breakage in the lower part of the column. By combining ethanol addition and sparger modification, bubble coalescence and bubble breakage can be decoupled in a controlled manner and interesting conclusions concerning these processes can be drawn. Beyond the novelty of bubble size measurements at high gas fraction, the experimental data collected are very useful to validate and develop computational fluid dynamics simulations coupled with population balance models suitable for heterogeneous bubbly flows
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