1,721,042 research outputs found
Which future for Italian high altitude lakes?
No full textAbstract: High altitude lakes and their fauna are one of the most threatened and less
investigated ecosystems in Italy. Alpine lakes are highly influenced by climate harshness
and by air pollution, and because of their small dimensions are extremely vulnerable to
global climate warming. Italy, in addition to the Alps, hosts another mountain range: the
Apennines, reaching in some cases comparable altitudes, and therefore subject to the
same risks. Moreover, the gentler slope of the Apennines makes them extremely
vulnerable even to direct human impacts. In the present work, for the first time, high
altitude lakes belonging to the Alps and to the Apennines are compared to highlight which
meteo-climatic or chemical characteristics could be considered key drivers for their
macrinvertebrate structure. The study area was explicitly focused on natural lakes placed
above 1300 m of altitude and above the 44° parallel, thus in the alpine area and subject to
a continental climate. 25 lakes were chosen (19 in the central-western Alps and 6 in the
Modenese Apennines) with surface areas lower than 1 km2 and with maximum depths
lower than 15 m. Physico-chemical parameters and macroinvertebrates were studied and
compared. Samples were taken through the use of an hand-net (250 μm mesh size) along
the littorals on different substrates following standardised methodologies during the richerfauna
season to allow an easier identification of species. Parallel to that, water samples
were collected and analysed. Species richness and the Taxonomic Distinctness Indices
were applied to underline the different complexity of the community structure of the two
areas. Results showed different macroinvertebrates communities with peculiar
characteristics and highlighted a more structured and diverse composition on the
Apennines. Predictive models on the future climate scenarios show how the peninsular
portion of Italy will be even more affected by the increase in temperatures than the Alpine
area. Thus, this work could be highly informative, mainly for central Italy, where proximity
to towns encourage tourists to reach these type of lakes, even if placed in protected areas
or parks. Therefore, protection and management plans, and conservation efforts of high
altitudes cannot overlooked a thorough understanding of the biological diversity of these
environments, which still appears fragmented and limited to some sector of the Alps.
Furthermore, the fundamental role of high altitude lakes as water resource needs a
specific management regime, as they are not included under the monitoring programs of
the Water Framework Directive legislation
Status quo of knowledges on Italian high altitude lacustrine macroinvertebrates
No full textHigh altitude lakes and their fauna are one of the most threatened and less investigated
ecosystems in Italy. Alpine lakes are highly influenced by climate harshness and by air
pollution, and because of their small dimensions are extremely vulnerable to global climate
warming. Italy, in addition to the Alps, hosts another mountain range: the Apennines,
reaching in some cases comparable altitudes, and therefore subject to the same risks.
Moreover, the gentler slope of the Apennines makes them extremely vulnerable even to
direct human impacts. In the present work, for the first time, high altitude lakes belonging
to the Alps and to the Apennines are compared to highlight which meteo-climatic or
chemical characteristics could be considered key drivers for their macroinvertebrate
structure. The study area was explicitly focused on natural lakes placed above 1300 m of
altitude and above the 44° parallel, thus in the alpine area and subject to a continental
climate. 25 lakes were chosen (19 in the central-western Alps and 6 in the Modenese
Apennines) with surface areas lower than 1 km2 and with maximum depths lower than 15
m. Physico-chemical parameters and macroinvertebrates were studied and compared.
Samples were taken through the use of a hand-net (250 μm mesh size) along the littorals
on different substrates following standardised methodologies during the richer-fauna
season to allow an easier identification of species. Parallel to that, water samples were
collected and analysed. Species richness and the Taxonomic Distinctness Indices were
applied to underline the different complexity of the community structure of the two areas.
Results showed different macroinvertebrates communities with peculiar characteristics and
highlighted a more structured and diverse composition on the Apennines. Predictive
models on the future climate scenarios show how the peninsular portion of Italy will be
even more affected by the increase in temperatures than the Alpine area. Thus, this work
could be highly informative, mainly for central Italy, where proximity to towns encourage
tourists to reach these type of lakes, even if placed in protected areas or parks. Therefore,
protection and management plans, and conservation efforts of high altitudes cannot
overlooked a thorough understanding of the biological diversity of these environments,
which still appears fragmented and limited to some sector of the Alps. Furthermore, the
fundamental role of high altitude lakes as water resource needs a specific management
regime, as they are not included under the monitoring programs of the Water Framework
Directive legislation
Alien and native species in Italian marine and transitional waters
No full textBiological invasions are one of the major threats to the ecosystem structure and functioning. After the initial introduction, frequently mediated by human activities, alien species can overcome different biogeographical and ecological barriers and determine severe impacts on native biodiversity and socio-economic activities. The Italian peninsula is located at the intersection of large trade routes within the Mediterranean Sea. Such position, along with the intense commercial activity and the high population density of the Italian coast, are considered important drivers of alien species in Italian marine and transitional ecosystems. The Italian peninsula, however, is also one of the regions with the highest native species richness within the Mediterranean Sea and, therefore, it is crucial to account for both alien and native species diversity when estimating the impact of biological invasion. Yet, such comprehensive information is frequently scattered across several biodiversity information systems and databases.Here, two datasets with alien and native species records in Italian marine and transitional waters are described. These datasets, created for the LifeWatch Italy case study on alien species, are the result of a large-scale collaboration involving experts working across the whole range of taxonomic diversity. The marine dataset includes a total of 12,219 records belonging to 3,772 species gathered from 91 investigated sites and seven EUNIS habitats. The dataset on transitional waters biodiversity includes 3,838 records belonging to 2,019 species found in 23 locations and four EUNIS habitats. Alien species were recorded in both marine and transitional waters, accounting respectively for 140 and 171 biological records belonging to 59 and 97 species. These occurrence data can be used for further research studies or management purposes, including the evaluation of the invasion risk and the formulation of alien species control and management plans. Furthermore, these compiled datasets can be used as input data for the Biotope vulnerability case study of LifeWatch ERIC, which offers a number of ICT services for the calculation of the incidence and of the impact of alien species on European biotopes
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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