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Late-Quaternary Meltwater Pulses investigated through sedimentological, micropaleontological and geochemical approach: preliminary results
No full textClimate changes and sea level rise during the next century are two of the main environmental challenges
to face by the modern society. Sea level change responds to a variety of processes including ocean thermal
expansion and ice sheet melting in the polar areas. The latter have been responsible for past abrupt relative
sea level rises known as meltwater pulses that deeply changed the Earth’s physiography after Last Glacial
Maximum by submerging the paleo coastal areas. Meltwater pulses are short-lived global acceleration in sealevel
rise resulting from intense glacial melting, surge of large ice streams into oceans and intense iceberg
discharge during ice sheet disintegration (Blanchon, 2011). The main concerns related to the present fast
global climate changing is the possibility that sudden drastic ice loss from Greenland and/or in the West
Antarctic Ice Sheet would lead to a new abrupt acceleration of the relative sea level rise with consequent
inundation of vast coastal areas and/or to cause an abrupt slowdown of the Atlantic Meridional Overturning
Circulation (i.e. Golledge et al., 2014). To better understand the dynamics and risks associated with the onset
of past meltwater pulses, their impact on thermohaline ocean circulation and climate it is pivotal the geological
study of the well preserved and most recent meltwater pulses events occurred during the Late Quaternary,
particularly those occurred during the Last Glacial Termination. Here, we present some preliminary results of
the sedimentological, micropaleontological and geochemical investigation of 4 sediment cores collected on the
Western margin of the Svalbard archipelago, next to the Fram Strait in the Artic
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
Paleoenviromental changes during the last 2 ka BP in the Eastern Side of Fram Strait.
No full textPolar regions regulate the climate through the heat exchange between ocean and atmosphere, the sea ice
formation or melting, and bottom water formation. Lately, the scientific community has been focusing on the
study of the last 2000 years. This interval gives information about climate natural variability versus change
induced by human activity. Moreover, the studies of environmental changes recorded in this period offer the
possibility to understand how our climate may evolve in the near future. This study is focused on the last 2 ka
BP and has the aim to understand the paleoenvironmental variations in the eastern side of Fram Strait, through
multidisciplinary micropaleontological and sedimentological analyses, focussing on the diatom assemblages.
Two long Calypso cores GS191-01 PC (19.68 m) and GS191-02 PC (17.37 m) were collected on the Bellsund
and Isfjorden Drift, during the expedition of RV G.O. Sars (5th–15th June 2014), in the framework of the
project Eurofleets-2 PREPARED. Here we present the study of the first 80 cm for core GS191-01PC and
the first 18 cm for core GS191-02 PC corresponding to the last 2 ka years BP. The investigated sedimentary
sequence is dominated by muddy, bioturbated sediments with very rare/sparse IRD (Ice Rafted Debris). The
Diatom assemblage was analysed every 2-cm, corresponding to a resolution of 30 years for GS191-01PC and
at every 1-cm in core GS191-02PC, corresponding to a resolution of 126 year. On the basis of the age model
proposed by Caricchi et al. (2019), the multi-proxy analyses on the diatoms and foraminifera assemblages, and
sedimentological data, allowed us to distinguish in the record four different climatic periods indicated as Units.
Unit A (2000 - 1500 cal yr BP) is the older, and indicates relatively warm conditions, suggesting the influence
of warm water with a cooling period between between 1800 to 1700 cal yr BP, characterized by increased sea
ice coverage and the presence of cold water masses.
In unit B (1500 - 1300 cal yr BP) is period of cooler conditions compared with the previous one, and it is
characterized by the presence of extended sea ice and a minor inflow of the warm water.
Unit C (1300- 700 cal yr BP) records a warming surface water with presence of freshwater of continentally
origin. Unit C ends with the worsening of climatic conditions characterized by a progressive cooling.
Unit D (700 cal yr BP to recent) represents a cooling period characterized by extended sea ice coverage and
an increased distribution of cold-water taxa
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
Tracking Late Quaternary ice sheet dynamics by multi-proxy detrital mineral U-Pb analysis: A case study from the Odyssea contourite, Ross Sea, Antarctica.
Full text linkL ate Quaternary Antarctic ice-sheet instability is recorded by ice-rafted debris (IRD) in mid- to highlatitude
marine sediment, especially during marine isotope stages (MIS) 2-3, but drivers of this
instability remain enigmatic (Labeyrie et al., 1986). A key step in resolving this puzzle is to
determine the location of iceberg calving sites, thus highlighting ice sheet sectors exhibiting
repeated instability. Single-grain U-Pb provenance analysis applied to clastic IRD provides a
suitable high-resolution tool for this task, and also permits discrimination of continental IRD from
volcanic material. The application of multiple proxies (apatite, rutile, and zircon) is critical in order
to reduce source area fertility biases: for example, the near exclusive occurrence of zircon in felsicintermediate
igneous rocks (e.g., Hietpas et al., 2010).
Here, we present detrital apatite, zircon, and rutile U-Pb data from samples taken from a gravity
core from the Odyssea contourite drift system, located on the margin of the Ross Sea (Rebesco et
al., 2018) and deposited during MIS2-3. Contourites are marine clastic sediment deposits forming
by along-slope, bottom currents reworking of fine-grained (clay-silt) sediments delivered by downslope
sedimentary processes (e.g. meltwaters, turbidity currents, debris flows). Crucially,
contourite targetting eliminates the challenge of distinguishing IRD from coarse (sand-gravel)
turbidite material in basin deposits, as ice-sheet instability is also associated with turbidite
production at glaciated shelf margins (e.g., Bart et al., 1999).
We couple our analysis with the multi-proxy sediment analyses previously performed by Lucchi et
al. (2019). We consider the implications of our data for the advance and retreat of the Antarctic Ice
Sheet during MIS 2-3, and discuss the further applicability of our multi-proxy approach around
Antarctica
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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