1,720,987 research outputs found
Evidences of carbonate preservation on the outer continental slope in the Western Ross Sea (Hallett Ridge and Central Basin, Antarctica)
No full textLate Quaternary Antarctic Ice Sheet (AIS) changes can be investigated by analyzing marine sediments (gravity and box cores) collected on the continental shelves and along the continental margins of Antarctica. These sites are strongly influenced by the ice sheet/shelf sediment drainage and inflow/outflow of polar water masses. In this respect, the continental slope of the Western Ross Sea (WRS) is still poorly studied, in particular its history is affected by uncertainties due to the scarcity of well-preserved calcareous foraminifera preventing the production of reliable age models.
We present the results of a study made on one gravity core (KI13-C2; Melis et al., 2021) and three box-cores (KI13-bc2, bc3 and bc4; Torricella et al., 2021) located on the Hallett Ridge and in the Central Basin where the presence of carbonate-rich intervals offers the opportunity, to time-reconstruct the AIS evolving changes since the Marine Isotopic Stage (MIS) 2. These intervals correlated with other carbonate layers identified in cores collected along the WRS continental slope provide important insights about a large-scale break-up of the ice shelf/sea ice system.
This study has been conducted in the framework of the STREAM Project (Late Quaternary evolution of the ocean-ice sheet interactions: the record from the Ross Sea continental margin, Antarctica; period 2019-2021), funded by the Italian Ministry of Foreign Affairs and International Cooperation and the National Research Foundation of Korea, and thanks to a grant approved by the Department of Mathematics and Geoscience, University of Trieste.
Bibliographic references
Melis R., Capotondi L., Torricella F., Ferretti P., Geniram A., Hong J.K., Kuhn G., Khim B.-K., Kim S., Malinverno E., Yoo K.C. and Colizza E. (2021) - Last Glacial Maximum to Holocene: paleoceanography of the northwestern Ross Sea inferred from sediment core geochemistry and micropaleontology at Hallett Ridge. J. of Micropal., 40, 15-35.
Torricella F., Melis R., Malinverno E., Fontolan G., Bussi M., Capotondi L., Del Carlo P., Di Roberto A., Geniram A., Kuhn G., Khim B.-K., Morigi C., Scateni B. and Colizza E. (2021) – Environmental and Oceanographic Conditions at the Continental Margin of the Central Basin, Northwestern Ross Sea (Antarctica) Since the Last Glacial Maximum. Geosciences, 11, 155
3° Convegno Nazionale per Giovani Ricercatori in Paleontologia - IVP Day 2020 – Abstract Booklet
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Contemporary ground-based and satellite precipitating system characterization for desertification studies in Southern Italy
No full textDuring the research project RIADE (Ricerca Integrata per l'Applicazione di tecnologie e processi innovativi per la lotta alla DEsertificazione), devoted to the study on the potential risk of desertification in Southern Italy, a particular attention has been paid also to the analysis of precipitations from three surface stations (Licata, Sicily; Rotondella, Basilicata; Surigheddu, Sardinia) in order to improve the knowledge derived from the most modern climatological studies related to this subject. The point of view adopted is to better define the precipitation microphysical properties (in particular, the Drop Size Distribution, DSD, and its moments), which are deeply related to the cloud system that generates the precipitation events. In particular we have used a newly introduced Convective Stratiform discrimination technique, that allowed us to observe a prevalence of events, concentrated along Winter (Wi) season, of different microphysical nature. In fact the prevailing Stratiform nature is related to Licata station, while for Surigheddu and for Rotondella the nature is mainly Convective. This distinction is related to the presence of drops of bigger dimensions and more intense precipitations in the latter case, while, in the former case, a prevalence of smaller drops and a less intense precipitation is recorded. This confirms the distinctive belonging to three different climatic regions, as indicated in the study by Brunetti et al. (2006). Our findings are important in the framework of desertification studies, because the cause of desertification can be related either to fertile soils removal (in the case of Convective events) or to lack of precipitated water (in the case of Stratiform events). We have also analysed a sub-set of ten events, with contemporary presence of data from VIS/IR channels of METEOSAT-7, SSM/I data from F13 and MODIS data from Terra platform. This has been done both to confirm the findings of PLUDIX data analysis (which is, in fact, confirmed) and to show the capability of PLUDIX to detect the fast local variations related to the temporal evolution of more extended systems. The potentiality of PLUDIX as a real-time detector of precipitation events, together with the development of an adequate number of algorithms, that give a complete microphysical description of the observed events, finally, opens the way for developing a new Present Weather Sensor
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
High resolution analytical forward model to be applied to high resolution sensors working in the ultraviolet and near infrared mounted onboard satellites
No full textVariations 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
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