1,720,965 research outputs found
Perceived benefits of littoral wetlands in Uganda: a focus on the Nabugabo wetlands
No full textWetlands, commonly called swamps in
Uganda, are estimated to cover about 13% of the total
land surface area (about 30,000 km2) of the country
and represent a considerable ecological, social and
economic value. In 1989, the Ugandan government
formerly recognised that wetlands need to be conserved
and contribute considerably to the National
economy and rural livelihood. The present analysis is
focused on the Nabugabo wetland ecosystem.
Located in Central Uganda, it is an important part
of the extensive system of wetlands that surround
Lake Victoria. The Nabugabo wetland is a source of
important resources that are basic to the local
economy, including fishing, water utilization, agriculture,
livestock, wetland plants for construction and
more recently, tourism. Investment in the area is low
and a large percentage of the local community
depends on the wetland resources for basic sustenance
needs. After achieving Ramsar status,
demarcation and conservation activities were initiated
by the local and national leaders. However, these conservation efforts have provoked conflicts between
the land owners and the policy makers, in particular
to the demarcation of areas for conservation In the
present analysis, we examine the benefits, perceived
by local leaders and community members, of the
wetland and its services, as well as views towards its
conservation and management. The results show that
differences between the community leaders and
member exist regarding the perceived benefits of
the wetlands. Tourism, while providing some opportunities
for local persons is not always viewed
positively. Conservation activities are viewed positively
but some questions remain as to whether such
efforts help or hinder the local population, in
particular regarding access to basic resources
Anthropogenic impacts on the Orbetello lagoon ecosystem
No full textThe aim of the present study was to assess the environmental quality of Orbetello lagoon (Tyrrhenian coast, Italy), using a biomonitoring method based on measuring organochlorinated pollutants in the Anguilla anguilla, chosen as sentinel organism, and remote sensing data obtained by elaboration of Landsat 7 Enhanced Thematic Mapper (ETM) data of 2002. Polychlorinated biphenyls and organochlorine pesticides were determined by gas chromatography/mass spectrometry in muscle of European eels captured in seven sites having different levels of pollution in Orbetello lagoon.
Remote sensing data and chemical analysis showed the Albegna river as a probable vehicle of
pesticides (hexachlorocyclohexanes)
Determination of acrylamide in local and commercial cultivar of potatoes from biological farm
No full textThis paper reports the results of a preliminary study on the characterization of parameters influencing formation of acrylamide in fried potatoes, from biological cultivation. The formation of acrylamide was investigated in relation to frying in biological extra virgin olive oil and commercial seed oil. Three different cultivars (Rossa di Colfiorito, Quarantina bianca genovese and Kennebec) were chosen. Asparagine, glucose, fructose and sucrose concentrations were determined in potato slice before frying, while acrylamide content was analysed by LC-ESI-MS/MS in the slices fried in seed and extra virgin olive oil. The Kennebec cultivar showed differences in its potential for acrylamide formation, which was primarily related to its relatively high asparagine and reducing sugars contents, respect the other local cultivars (particulary Quarantina). Values of acrylamide below detection limit (LOD) were found in Quarantina bianca genovese cultivar samples fried in extra virgin olive oil and peanuts seed oil and higher in peanuts seed oil fried potatoes of Kennebec cultivar
A combinated approach to investigate the biochemistry and hydrography of a shallow bay in the South Adriatic Sea: The Gulf of Manfredonia (Italy)
No full textThe main goal of this study is to understand the hydrological and biochemical set up and processes of a marine coastal area located in the western side of the south Adriatic sea (the gulf of Manfredonia) by the use of both satellite images and in situ investigations A water sampling in the gulf of Manfredonia was performed at 18 fixed stations in June 2003; physico-chemical and biological parameters (temperature, salinity, dissolved oxygen and fluorescence) were measured along the water column and water samples were collected to analyse dissolved nutrients (ammonia, nitrite, nitrate, phosphate and silicate), total nutrients (nitrogen and phosphorus), chlorophyll a and total suspended solids. Surface spatial distributions of field collected data were examined to characterize biochemical and hydrographic conditions of the Gulf of Manfredonia and these results were related with the remote sensing analysis data. Remote sensed data (obtained by Landsat 7 TM and Modis Terra) were processed to obtain maps of chlorophyll a, temperature and optical characteristics of the gulf; these maps were compared to in situ data. From physico-chemical measurements no stratification was observed in the water column except for the south-eastern area. High concentrations of silicate and ammonia were observed in the northern zone of the gulf, while nitrate, phosphate, chlorophyll a and total suspended solids distributions showed higher values in the central coastal zone. These results were confirmed by remote sensing analysis; Modis elaboration showed a distribution with higher concentrations of chlorophyll a near the coast and Landsat images highlighted the extension of the surrounding agricultural areas crossed by the two main rivers which discharge into the gulf. The integration between field data with the remote sensing analysis showed to be a valid support in coastal zone management
Production of bio-diesel from macro-algae of the Orbetello lagoon by various extraction methods
No full textIn the last few years, there has been a significant increase in finding alternative energy sources to fossil fuel. Bio-diesel derived from vegetable oils has been shown to be a potential alternative. Presently, most of the available bio-diesel is made from edible oils, but it is believed that with a large-scale production of bio-diesel these stocks may cause an imbalance to the food supply. Algae and aquatic bio-mass have the potential to provide a new range of third generation bio-fuels. Recently, there has been substantial increase in attention to the possibility of using aquatic bio-mass. The aim of this study was to evaluate the macro-algae oil yield and lipid composition in order to produce bio-diesel from waste bio-mass. The algal bio-mass comes from the Orbetello lagoon (Southern Tuscany, Italy), where macro-algae grow naturally due to eutrophication and are harvested and stored in a landfill as a special waste product. Lipid extraction was carried out according to the Bligh and Dyer method and also by using a Dionex ASE200 (accelerated solvent extractor). The total lipid content was determined by micro-gravimetry and the fatty acids (FAs) by GC-FID and GC-MS after acid transesterification. Chaetomorpha linum was the most abundant species and had the highest lipid content. Lipid concentrations and profiles of the Orbetello lagoon's macro-algae were comparable with those reported in the literature for the same species or genus. Algal FAs corresponded to those that normally constitute bio-diesel. Thus, the results indicate that bio-diesel could be produced from the harvested algal bio-mass. © 2013 Taylor & Francis
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
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