1,721,107 research outputs found
Climate variability and international migration: an empirical analysis
Full text linkIs international migration an adaptation strategy to sudden or gradual climatic shocks? In this paper we investigate the direct and the indirect role of climatic shocks in developing countries as a determinant of out-migration flows toward rich OECD countries in the period 1990–2001. Contrarily to the bulk of existing studies, we use a macro approach and explicitly consider the heterogeneity of climatic shocks (type, size, sign of shocks and seasonal effects). Our results show that the occurrence of adverse climatic events in origin countries has significative direct and indirect effects on out-migration from poor to rich countries
Scanning electrochemical microscopy: using the potentiometric mode of SECM to study the mixed potential arising from two independent redox processes
No full textThis study demonstrates how the potentiometric mode of the scanning electrochemical microscope (SECM) can be used to sensitively probe and alter the mixed potential due to two independent redox processes provided that the transport of one of the species involved is controlled by diffusion. This is illustrated with the discharge of hydrogen from nanostructured Pd hydride films deposited on the SECM tip. In deareated buffered solutions the open circuit potential of the PdH in equilibrium between its ? and ? phases (OCP???) does not depend on the tip–substrate distance while in aerated conditions it is found to be controlled by hindered diffusion of oxygen. Chronopotentiometric and amperometric measurements at several tip–substrate distances reveal how the flux of oxygen toward the Pd hydride film determines its potential. Linear sweep voltammetry shows that the polarization resistance increases when the tip approaches an inert substrate. The SECM methodology also demonstrates how dissolved oxygen affects the rate of hydrogen extraction from the Pd lattice. Over a wide potential window, the highly reactive nanostructure promotes the reduction of oxygen which rapidly discharges hydrogen from the PdH. The flux of oxygen toward the tip can be adjusted via hindered diffusion. Approaching the substrate decreases the flux of oxygen, lengthens the hydrogen discharge, and shifts OCP??? negatively. The results are consistent with a mixed potential due to the rate of oxygen reduction balancing that of the hydride oxidation. The methodology is generic and applicable to other mixed potential processes in corrosion or catalysi
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
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