1,720,981 research outputs found
Sea-level rise in the Mediterranean Sea by 2050: Roles of terrestrial ice melt, steric effects and glacial isostatic adjustment
No full textTo assess the regional pattern of future low-frequency sea-level variations in the Mediterranean Sea, we combine the terrestrial ice melt, the glacio-isostatic and the steric sea-level components. The first is obtained from global scenarios for the future mass balance of the Greenland and Antarctica ice sheets, glaciers and ice caps. The second is based on modeling, using different assumptions about the Earth's rheology and the chronology of deglaciation since the Last Glacial Maximum. The third is obtained from published simulations based on regional atmosphere–ocean coupled models. From a minimum and a maximum scenario by 2040–2050, we find that the total, basin averaged sea-level rise will be 9.8 and 25.6 cm. The terrestrial ice melt component will exceed the steric contribution, which however will show the strongest regional imprint. Glacial isostatic adjustment will have comparatively minor effects. According to our estimates, at the Mediterranean Sea tide gauges, the rate of sea-level change will increase, by 2050, by a factor of ~ 1–6 relative to the observed long-term rates
Modeling sea level changes and geodetic variations by glacial isostasy: the improved SELEN code
No full textWe describe the basic features of SELEN, an open source Fortran 90 program
for the numerical solution of the so-called "Sea Level Equation" for a
spherical, layered, non-rotating Earth with Maxwell viscoelastic rheology. The
Sea Level Equation was introduced in the 70s to model the sea level variations
in response to the melting of late-Pleistocene ice-sheets, but it can be also
employed for predictions of geodetic quantities such as vertical and horizontal
surface displacements and gravity variations on a global and a regional scale.
SELEN (acronym of SEa Level EquatioN solver) is particularly oriented to
scientists at their first approach to the glacial isostatic adjustment problem
and, according to our experience, it can be successfully used in teaching. The
current release (2.9) considerably improves the previous versions of the code
in terms of computational efficiency, portability and versatility. In this
paper we describe the essentials of the theory behind the Sea Level Equation,
the purposes of SELEN and its implementation, and we provide practical
guidelines for the use of the program. Various examples showing how SELEN can
be configured to solve geodynamical problems involving past and present sea
level changes and current geodetic variations are also presented and discussed
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
Post-LGM coastline evolution of the NW Sicilian Channel: Comparing high-resolution geophysical data with Glacial Isostatic Adjustment modeling
Full text linkSince about 20,000 years ago, the geography of the Earth has been profoundly modified by the gradual sea-level rise caused by the melting of continental ice sheets. Flat areas and regions characterized by very low gradients experienced, more than others, rapid flooding, with the progressive disappearance of vast coastal territories. Here we present a recon- struction of the late Quaternary coastline evolution of the north-western sector of the Sicilian Channel, constrained by high-resolution seismic profiles where the marker of the post-Last Glacial Maximum (LGM) marine transgression has been clearly identified and mapped. The locations of the post-LGM seismic horizon have been compared with predictions of a Glacial Isostatic Adjustment (GIA) model, which accounts for the migration of the shorelines in response to sea-level rise and for Earth’s rotational and deformational effects associated with deglaciation. We have verified that most of the points mapped through seismic data interpretation fall along the palaeo-coastline that the GIA model predicts for the 21 kyrs B.P. time frame. However, the model shows a misfit in the marine sector between Mazara del Vallo and Sciacca, where the available data indicate a Quaternary tectonic uplift. The analy- sis of the seismic profiles provides useful constraints to current GIA models. These add on existing histories of relative sea level in the Mediterranean Sea, allowing to gain new insight into the evolution of the palaeo-geography of the region of study and of the whole Sicilian Channel since the LGM, even in areas where direct geophysical observations are not avail- able yet. In this respect, one of the most attractive implications of the ancient coastline evo- lution is linked with the underwater archaeology. The sea-level rise heavily impacted the distribution of human settlements, possibly forcing site abandonment and migrations, and this is particularly relevant in the Mediterranean basin, the cradle of the western civilization. The underwater traces left by these ancient populations represent the fundamental proofs to reconstruct the early history of our precursors
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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