1,721,040 research outputs found
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
Modeling distribution of Mediterranean beech forests and soil carbon stock under climate change scenarios
No full textClimate change is forecasted to alter forest species distributions and the organic carbon cycle, particularly in the Mediterranean region. In this context, one of the most important carbon reservoirs, both in terms of living biomass and soil organic matter, is represented by beech forests, which are highly vulnerable to global warming. Accordingly, we investigated how the effects of climate change predicted for 2070 could affect both beech distribution and soil carbon stocks in Italy. In order to achieve this goal, we predicted beech distribution using state of the art ecological niche modeling, projecting its potential range under climate change scenarios. Moreover, a field survey was carried out to quantify the proportion of organic carbon in the first 5 cm of soil, which are the most sensitive to climate effects. The latter results were used to explore the relationship between organic carbon and ecogeographical variables, projecting this relationship onto the predicted beech distribution. Our outcomes showed a substantial reduction in beech distribution, especially at its southern range limits, along with a remarkable shift towards higher elevations and latitudes. The organic carbon in beech forests was significantly related to temperature seasonality and elevation, showing a decrease between 64.5 and 98.8% under different IPCC scenarios
Field and microcosms decomposition dynamics of European beech leaf litter: Influence of climate, plant material and soil with focus on N and Mn
No full textLeaf litter decomposition is one of the key phenomena in forest ecology. The patterns and trends of
decomposition are related to the complex interaction of climate, soil biota and litter quality. The decay
dynamics for the European beech are well-known for middle Europe, but lesser investigated in the
Mediterranean area. In this study, we investigated mass loss and nutrient dynamics, especially nitrogen
and manganese, in two Mediterranean beech forest located in northern and southern Italy. We used a
litterbag experiment with leaves of each forest incubated in their own area of origin and vice versa.
Moreover, we also used microcosms to follow early stages of decomposition under controlled conditions.
The aims of this study were to investigate the role of climate and soil/litter quality at the different stages
of decomposition and assess the response of diverse soils to changes in temperature and humidity. The
results showed a faster field decomposition for the southern (warmer) site compared to the northern
(colder) site, whereas under stable conditions in microcosms this trend reversed, implying different
microbial adaptations to climate. Moreover, changes in temperature and humidity triggered complex
microbial response during litter decay. Additionally, whereas our results showed trends of nitrogen
concentration comparable to previous studies, the role of manganese in decomposition was very relevant
even from the early stages. Noticeably, manganese was generally lower in both sites compared to middle
Europe, but it was higher in the northern site than in the southern one. Manganese concentration,
however, strongly increased for those leaves that had a lower initial content in all conditions, giving
evidence of a strong mobilization of this nutrient and its essential role for decomposition in
Mediterranean beech forests.Leaf litter decomposition is one of the key phenomena in forest ecology. The patterns and trends of decomposition are related to the complex interaction of climate, soil biota and litter quality. The decay dynamics for the European beech are well-known for middle Europe, but lesser investigated in the Mediterranean area. In this study, we investigated mass loss and nutrient dynamics, especially nitrogen and manganese, in two Mediterranean beech forest located in northern and southern Italy. We used a litterbag experiment with leaves of each forest incubated in their own area of origin and vice versa. Moreover, we also used microcosms to follow early stages of decomposition under controlled conditions. The aims of this study were to investigate the role of climate and soil/litter quality at the different stages of decomposition and assess the response of diverse soils to changes in temperature and humidity. The results showed a faster field decomposition for the southern (warmer) site compared to the northern (colder) site, whereas under stable conditions in microcosms this trend reversed, implying different microbial adaptations to climate. Moreover, changes in temperature and humidity triggered complex microbial response during litter decay. Additionally, whereas our results showed trends of nitrogen concentration comparable to previous studies, the role of manganese in decomposition was very relevant even from the early stages. Noticeably, manganese was generally lower in both sites compared to middle Europe, but it was higher in the northern site than in the southern one. Manganese concentration, however, strongly increased for those leaves that had a lower initial content in all conditions, giving evidence of a strong mobilization of this nutrient and its essential role for decomposition in Mediterranean beech forests. (C) 2015 Elsevier B.V. All rights reserved
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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