1,720,990 research outputs found
Multisensor monitoring of plume dynamics in the north-western Mediterranean
No full textWe used data from various space-borne sensors to monitor the marine ecosystem in the northwestern Mediterranean Sea, at the Costa Dorada, between the City of Barcelona and the estuary of the river Ebro. The aim of this study was to demonstrate that the combination of different remote sensing data (acquired at different electromagnetic frequencies) allows for an improved monitoring system, in particular for a better monitoring of the marine ecosystem and, hence, a better coastal zone management. We present remote sensing data acquired by the Synthetic Aperture Radar (SAR) and the Along-Track Scanning Radiometer (ATSR) aboard the Second European Remote Sensing Satellite (ERS-2), and by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) on the SeaStar satellite. By combining the different data we are able to overcome specific drawbacks of the single sensors, like an insufficient temporal coverage, or a strong dependence on weather and daylight conditions. Within the study area two main features have been selected as examples, which are well visible on many of the analysed images. The first one exhibits a higher load of chlorophyll-a and surface-active compounds and a lower sea surface temperature (SST), which is likely to be caused by the plume of the river Llobregat, southwest of Barcelona. It can clearly be seen from the imagery how the river plume is driven along the coast by the local currents. The second feature can be related to cooling water being released from a nuclear power plant and causing turbulence in the water body, which in turn gives rise to signatures visible on the ERS-SAR imagery
Analisi dei campi di colore, temperatura e vento per la classificazione delle province geografiche del Mare Mediterraneo
Full text linkWater constituents in the north-western Black Sea from optical remote sensing and In situ data
No full textBiogeochemical transformations of inorganic nutrients were studied in the mixing zone between the Danube and the north-western Black Sea in July 1995 and in the winter–spring transition period of 1997. Inorganic nutrients, phytoplankton carbon-biomass and biogenic silica were analysed at 10 different locations across the entire salinity gradient in combination with parallel measurements of phytoplankton carbon and inorganic nutrient uptake rates, making use of different tracers (14C, 15N, 32Si and 32P). The quantitative and qualitative nutrient signature of the Danube outflow into the Black Sea varied seasonally, depending on upwards processes of consumption, remineralization, transformation and elimination. Danube DSi (dissolved silicon) and DIN concentrations decreased from winter to summer, although PO4 remained constant for the whole season. The winter distribution of inorganic nutrients along the salinity gradient was conservative, and phytoplankton biomasses and activities were very low due to strong light limitation. However, significant phytoplankton carbon and inorganic nutrient uptake rates were measured in early spring and during summer at salinities depending on the hydrodynamics of the Danube and Black Sea mixing. Between a salinity of 0 and 10 (using the Practical Salinity Scale), phytoplankton (diatom) growth and mortality processes have been evidenced, which at first strongly lower the inputs of inorganic nutrients to the coastal zone, but also affect the balance among which nutrients are spread over the shelf. These modifications have important consequences for phytoplankton dynamics and species dominance at salinities above 10; diatom growth being apparently P-limited during spring and N-limited during summer. Surprisingly, no DSi limitation of diatom growth has been shown during this study, and a background DSi level of 2–3 M was measured in the entire shelf area. Causes for such an observation appear to be (1) an efficient biotic and abiotic removal of PO4 during mixing, (2) an important denitrification in the upper estuary and (3) an important recycling of Si, both in the water column and at the sediment–water interface. The negative long-term effect of the quantitative and qualitative (deficiency in DSi) changes of the Danube inputs on the functioning of the Black Sea pelagic and benthic food-webs have been clearly reported in the literature and cannot be questioned by the present data set. Rather, this study simply highlights the complexity of the mechanisms by which propagation of the Danube eutrophication beyond the river plume possibly occurs
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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