1,720,961 research outputs found
Integrating field survey on geo-environmental factors and orthophoto information to monitor coastal dune habitats – A pilot study to evaluate coastal dune vulnerability
No full textPlants play a crucial role in coastal sand dune development, because they interact directly with wind action, preventing sand movement. Vegetation works like an obstacle, in fact it deforms air flow and prevents sediment transport causing the decrease of the energy transfer. The interaction between vegetation, sand and wind shapes the coastal landscape, which is characterised by a sequence of different plant communities in accordance to a sea-inland ecological gradient mainly determined by salt spray, substrate incoherence, nutrient scarcity, water deficit, and high irradiance. Coastal ecosystems can be difficult to monitor effectively in the field because of the heterogeneity and discontinuity of these habitats. Integrating field analysis on several environmental variables with vegetation coverage obtained by orthophotos can be a challenging method to monitor coastal dune habitats. In particular, the aim of the present research is to integrate abiotic and biotic information to develop a vulnerability index in order to determine the conservation status of coastal dunes. This study has been planned in two pilot sites: Migliarino - San Rossore - Massaciuccoli Regional Park in Italy (Mediterranean Sea), and Acarai National Park in Brazil (Atlantic Ocean). In both sites, the following data will be collected: a) distribution and coverage of the different plant communities classified in three natural cover types (pioneer annual vegetation, herbaceous vegetation growing on embryonic and mobile dunes, shrub and woody vegetation of fixed dunes); b) geomorphological and sedimentological information (such as topography and sediment transport rate); c) acquisition of a set of environmental parameters (wind speed and direction, ground temperature and humidity) by means of wireless sensor technology. Relationships between plant communities coverage, geomorphological and sedimentological data, and environmental variables are investigated through Canonical Correspondence Analysis (CCA). An index of coastal dune vulnerability will be built integrating vegetation condition, geomorphological and sedimentological information, wind influence, and soil parameters. Results from the two pilot studies can be used for management and conservation planning
A wireless sensor network for the real-time remote measurement of aeolian sand transport on sandy beaches and dunes
Full text linkDirect measurements of aeolian sand transport on coastal dunes and beaches is of
paramount importance to make correct decisions about coast management. As most of the existing
studies are mainly based on a statistical approach, the solution presented in this paper proposes
a sensing structure able to orient itself according to wind direction and directly calculate the
amount of wind-transported sand by collecting it and by measuring its weight. Measurements
are performed remotely without requiring human action because the structure is equipped with
a ZigBee radio module, which periodically sends readings to a local gateway. Here data are
processed by a microcontroller and then transferred to a remote data collection centre, through
GSM technology. The ease of installation, the reduced power consumption and the low maintenance
required, make the proposed solution able to work independently, limiting human intervention, for all
the duration of the expected experimental campaign. In order to analyze the cause-effect relationship
between the transported sand and the wind, the sensing structure is integrated with a multi-layer
anemoscope-anemometer structure. The overall sensor network has been developed and tested in
the laboratory, and its operation has been validated in field through a 48 h measurement campaign
A technical solution to assess multiple data collection on beach dunes: the pilot site of Migliarino San Rossore Regional Park (Tuscany, Italy)
Full text linkCoastal dunes are a complex environment characterized
by several biotic and abiotic factors that concur to their evolution
and development. A whole comprehension of the interplay
between those factors is paramount to a wider definition of dune
systems: in some cases focusing on a factor at once is not suffice to
get satisfying insights. Here is proposed an integrated solution involving
different disciplines in order to collect in-depth datasets within
a short span of time on a selected site located in the Migliarino – San
Rossore – Massaciuccoli Regional Park (Tuscany, Italy). Geological
(geomorphology, sedimentology, and geophysics) and biological
aspects of the coastal dunes will be assessed using traditional survey
analyses and integrated with state-of-the-art technologies (UAV
flights, wireless sensors) to get an all-around characterization of the
ecosystem. A Wireless Sensor Network will be set up on the selected
site to measure in real-time physical parameters such as wind speed
and direction, soil moisture and sand dune volume and height variations.
The ensuing data will be stored to create a database that
might be used for management purposes. The aim of the paper is
to provide a modern, inexpensive, and easy to reproduce system to
monitor the evolution of any coastal dune field
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
Multidisciplinary study of the coastal dune system stability through the analysis of abiotic and biotic factors: a comparison between the Mediterranean (Italy) and Atlantic Ocean (Brazil).
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
Morpho-sedimentological and vegetational characterization of Grande beach at São Francisco do Sul Island (Santa Catarina, Brazil)
Full text linkA multidisciplinary study based on several digital (geology, lithology, shoreline evolution, photo-interpretation of aerial and ortho-photographs) and field (topographic and vegetational surveys, grain-size analysis) datasets prompted new insights to a better definition of the processes in action at the Grande beach at São Francisco do Sul Island (Santa Catarina, Brazil). The resulting data enabled us to produce a multi-thematic map at 1:50,000 scale that might be useful in assisting decision-makers to manage the coastal system, taking into account involved factors at once and not separately. In addition, the map may be implemented and integrated with new information, since the database is provided in geographical information system. The results confirmed the importance of addressing coastal systems with a multi-faceted approach that can be applied everywhere, not only in settings similar to São Francisco do Sul Island.</p
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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