1,721,303 research outputs found
VibEuroNet - Viburnum lantana observation Network in Europe: manual to implement a pilot study
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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
Extension of the Swiss Lateglacial tree-ring chronologies
No full textFossil wood finds reveal a high resolution paleoclimatic proxy record of Lateglacial and Early Holocene. Eighty-one
buried fossil pine stumps have been excavated on the construction site (Gaenziloo) of the A4-highway tunnel through
Uetliberg near Zurich (Switzerland). The trees were buried during their lifetime by loamy alluvia washed down from
the upper part of the slopes. The stumps have remained well preserved for more than 13,500 years. The cross sections
of the trunks were analyzed dendrochronologically. The sections were dated by 14C, and 14C age vs. ring number were
obtained from decadal sample segments.
Three floating chronologies were built. They cover a time span of 428 years in the Mid-Allerød (GAEALLCH_A),
561 years in the Late-Allerød (GAEALLCH_D) and 212 years in the Younger Dryas (GAEYD_A). Visual
synchronization, t-values, percentages of parallel variation (‘Gleichlaeufigkeit’) and radiocarbon wiggle matching
(14C age determinations on a decadal scale) as well as a check by the program Cofecha support the validity of the
resulting chronologies.
The two Allerød-chronologies from Gaenziloo were linked with two chronologies from Daettnau (DAEALCH_1
and DAEALCH_2) published by Kaiser, K.F. (1993. Beitra ̈ ge zur Klimageschichte vom Hochglazial bis ins fru ̈ he
Holoza ̈ n, rekonstruiert mit Jahrringen und Molluskenschalen aus verschiedenen Vereisungsgebieten. Ziegler Druck-
und Verlags-AG, Winterthur. 206pp). They extend the existing floating Swiss chronology in the Late-Allerød by a total
of 186 years. Unfortunately independent chronology GAEYD_A does not overlap with the actual absolute chronology
developed by the tree-ring laboratory of the University of Hohenheim (Friedrich, M. et al., 2004. The 12,460 year
Hohenheim oak and pine tree-ring chronology from Central Europe – A unique annual record for radiocarbon
calibration and paleo-environment reconstructions. Radiocarbon 46(3), 1111–22.)
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
Temporal and spatial distribution of ozone symptoms across Europe from 2002 to 2014
No full textOne of the aims of ICP Forest is to estimate the potential risk of ozone on European forest
ecosystems. In this respect, ozone-induced, visible foliar injury is one of the most considered
response indicator to assess ozone impact on vegetation. In the present study, we analyze
visible injury data from the Light Exposed Sampling Sites (LESS) installed close to the Level
II monitoring plots, and where ozone concentration and meteorological parameters are also
measured.
Over the period of 2002-2014, nineteen European countries participated in the field
assessment of ozone visible injury according to the ICP Forests standardized methodology
(Schaub et al., 2010). Overall, 295 woody species were recorded, of which 28% are being
reported as symptomatic*. In 2009, the year with the highest number of countries
participating in the field campaign, 60% of the countries reported the presence of ozone
symptoms in some plants. In the same year, 12.4% (24 out of 194) of the woody species
were symptomatic.
Preliminary results for temporal trends reveal that four out of five countries with at least eight
years of data show a decreasing trend in frequency of symptomatic woody species,
statistically significant for two countries. Enhanced data quality control is being carried out to
perform further analyses to better quantify the spatial and temporal distribution of ozone
symptoms across European forests, also in relation to ozone exposure (cf. Schaub et al.,
2015)
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