131,325 research outputs found
Assessing the Influence of Polymer-Based Anti-Drift Adjuvants on the Photolysis, Volatilization, and Secondary Drift of Pesticides after Application
No full textOne practice to reduce spray drift during pesticide application is the addition of certain chemical adjuvants to spraying solutions, which change their physicochemical properties and result in larger droplets. The environmental impact of these agrochemicals continues however also after application, depending on surface processes occurring upon treated surfaces. While the impact of anti-drift adjuvants has been studied regarding spray drift, their impact on the fate of deposited pesticides has received little attention. Here, the effect of a polymer-based adjuvant (polyacrylamide) on the photolysis and evaporation rates of pyrimethanil (common fungicide) from dry films were investigated under controlled laboratory conditions and during two field studies. The laboratory results indicate that the adjuvant enhances the volatilization and photolysis rate both on hydrophobic lemon leaves and hydrophilic glass substrates. These results can be attributed to an increase in the geometrical area of residual film and a widening of its circumference rim, where solutes are likely to concentrate, when generated from adjuvant-containing droplets. Such morphological differences may enhance the exposure of deposited pesticides to interact with the overlaying atmosphere and incident radiation. The field data was less conclusive, suggesting a small impact of the anti-drift adjuvant on the fungicide’s secondary drift from crops and an even lower effect on volatilization from bare soil
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The Epidemiology of Dementia and Alzheimer's Disease
No full textOur understanding of the epidemiology of Alzheimer disease (AD) has advanced rapidly during the past
decade. Community (population) studies in many countries have confirmed that the prevalence of AD
(and of vascular dementia) rises exponential fashion at least between ages 65 and 85, doubling with every 5 years of age; comparison of population studies between different countries has shown
age-specific prevalence rates to be similar within a factor of two among countries as diverse as China, Japan, Great Britain, France, Italy, and the United States. From these population studies other demographic factors, including gender (women may be more susceptible to AD than men), poor education, and perhaps certain occupations have emerged as important putative risk factors. Moreover, case-control and longitudinal studies have confirmed the importance of family history as a major risk factor, and other, somewhat unexpected risk factors, such as head trauma and coronary artery disease, have been identified. From these findings, together with current knowledge of molecular, genetic, and pathological features of AD, a picture emerges of the interaction over time of these risk factors with the biological factors that lead to the development of the Alzheimer process
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
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
sj-docx-1-caj-10.1177_08465371231220885 – Supplemental material for Deep Learning for Pneumothorax Detection on Chest Radiograph: A Diagnostic Test Accuracy Systematic Review and Meta Analysis
No full textSupplemental material, sj-docx-1-caj-10.1177_08465371231220885 for Deep Learning for Pneumothorax Detection on Chest Radiograph: A Diagnostic Test Accuracy Systematic Review and Meta Analysis by Benjamin D. Katzman, Mostafa Alabousi, Nabil Islam, Nanxi Zha and Michael N. Patlas in Canadian Association of Radiologists Journal</p
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
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
Scholarly Communication and Publishing Lunch and Learn Talk #11: The ULS Open Access Author Fee Fund
No full textAt the May 2014 talk, you will learn about the ULS Open Access Author Fee Fund--what it is, why we do it, how it works, and how the program is going so far
Frobenius test exponents for parameter ideals in generalized Cohen-Macaulay local rings
No full textThis paper studies Frobenius powers of parameter ideals in a commutative Noetherian local ring R of prime characteristic p. For a given ideal a of R, there is a power Q of p, depending on a, such that the Qth Frobenius power of the Frobenius closure of a is equal to the Qth Frobenius power of a. The paper addresses the question as to whether there exists a uniform Q(0) which 'works' in this context for all parameter ideals of R simultaneously.
In a recent paper, Katzman and Sharp proved that there does exists such a uniform Q(0) when R is Cohen-Macaulay. The purpose of this paper is to show that such a uniform Q(0) exists when R is a generalized Cohen-Macaulay local ring. A variety of concepts and techniques from commutative algebra are used, including unconditioned strong d-sequences, cohomological annihilators, modules of generalized fractions, and the Hartshome-Speiser-Lyubeznik Theorem employed by Katzman and Sharp in the Cohen-Macaulay case. (c) 2006 Elsevier Inc. All rights reserved
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