124,793 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
Palaeobotanical and geochronological evidence for the Alpine age of the metamorphism in the Sesia-Zone
No full textDas Alter der letzten Metamorphose der Sesia-Zone wurde lange Zeit für herzynisch oder älter gehalten. Als Argument dienten Grundgebirgseinschlüsse in den Trachyandesiten bis Andesiten der Sesia-Zone. Diese Vulkanite hielt man in Analogie zu den permischen Vulkaniten der Südalpen für permisch. In jüngster Zeit wurden in Tuffiten der Sesia-Vulkanite Pflanzenreste gefunden, die als oberkarbonisch beschrieben wurden. Diese Schlüsse standen in Diskrepanz zu strukturgeologischen Beobachtungen und zu den zahlreichen radiometrischen Altersbestimmungen in der Sesia-Zone und zwangen zur nochmaligen überprüfung der paläobotanischen Evidenzen. Die von uns gefundene Flora weist sehr moderne Züge auf und läßt sich mit Sicherheit ins Tertiär einstufen. Kein einziges paläozoisches Fossil wurde gefunden. Das durch die Pflanzenreste bestätigte tertiäre Alter der Vulkanite konnte mit radiometrischen K-Ar-Gesamtgesteinsaltern auf 29–33 m.y. präzisiert werden. Die letzte Hochdruck-Metamorphose in der Sesia-Zone fand nach K-Ar-Altersbestimmungen an Glimmern zwischen 60 und 90 m. y. statt. Vor ca. 38 m. y. wurden die alpeneinwärts liegenden Partien der Sesia-Zone von der lepontinischen Kristallisationsphase in Grünschieferfazies überprägt.For a long time the age of the last metamorphism of the Sesia-zone was considered to be Hercynian or older. Basement inclusions in basic volcanics were the main argument for this interpretation. The Trachyandesites — Andesites of the Sesia-zone were regarded as Permian, analogoues to the widespread Permian volcanics of the Southern Alps. Recently, plant remnants have been found in tuffitic interlayers of the Sesia volcanics. These fossils have been described as palaeozoic plants, in contradiction to structual observations and to the numerous radiometric data acquired in the region. To check the age of the fossils a detailed palaeobotanical study was carried out. Our samples contained a very modern flora of definitely Tertiary age. Not one palaeozoic fossil was detected. The Tertiary age found on palaeobotanical evidence proved to be between 29 and 33 m. y. on the basis of total rock K-Ar ages. The last high pressure metamorphism of the Sesia-zone occurred between 90 and 60 m. y. as has been shown by radiometric ages on micas. The external part of the zone was overprinted by the Lepontine phase of metamorphism in greenschist facies 38 m. y. ago
Species positions and extinction dynamics in simple food webs
No full textRecent investigations on the structure of complex networks have provided interesting results for ecologists. Being inspired by these studies, we analyse a well-defined set of small model food webs. The extinction probability caused by internal Lotka-Volterra dynamics is compared to the position of species. Simulations have revealed that some global properties of these food webs (e.g. the homogeneity of connectedness) and the positions of species therein (e.g. interaction pattern) make them prone to modelled biotic extinction caused by population dynamical effects. We found that: (a) homogeneity in the connectedness structure increases the probability of extinction events; (b) in addition to the number of interactions, their orientations also influence the future of species in a web. Since species in characteristic network positions are prone to extinction, results could also be interpreted as describing the properties of preferred states of food webs during community assembly. Our results may contribute to understanding the intimate relationship between pattern and process in ecology. © 2002 Elsevier Science Ltd. All rights reserved
Structure of the core complex of Blastochloris viridis and of Rhodobacter sphaeroides
No full textIn purple photosynthetic bacteria, two light harvesting complexes
(LH), LH2 and LH1, ensure the collection of light. Then, the excitation
energy is funneled towards the reaction center (RC), where after
two photoreactions and proton captures, ubiquinol (QH2) formed
at the QB site of the RC dissociates into the membrane. The cytochrome
(cyt) bc1 complex utilizes QH2 and oxidized cytochrome c2
as reductant and oxidant, respectively. The net result is a cyclic
electron transfer that promotes the formation of a proton gradient
across the membrane, which is utilized for ATP synthesis by
F1F0ATPsynthase (for review see Hu 2002, #1264). The description
of the bacterial photosynthetic apparatus at atomic level is nearly
complete with the structures of two RC, two LH2, and the cytochrome
bc1 complex (see http://blanco.biomol.uci.edu/Membrane_
Proteins_xtal.html). The last component not yet solved is the core
complex formed by the LH1 and the RC, in which the transformation
of light energy into charge separation occurs. A central
question is the coupling between the RC and the cytochrome bc1
complex, or how the quinones produced by the RC are transferred
through the LH1 fence to reach the cytochrome bc1 complex.
Here we present the structural analysis of two different core complexes,
from Blastochloris (Blc.) viridis and from Rhodobacter (Rb)
sphaeroides
Pragmatic Case Studies as a Source of Unity in Applied Psychology
No full textTo unify or not to unify applied psychology: that is the question. In this article we review pendulum swings in the historical efforts to answer this question—from a comprehensive, positivist, “top-down,” deductive yes between the 1930s and the early 60s, to a postmodern no since then. A rationale and proposal for a limited, “bottom-up,” inductive yes in applied psychology is then presented, employing a case-based paradigm that integrates both positivist and postmodern themes and components. This paradigm is labeled “pragmatic psychology” and, its specific use of case studies, the “Pragmatic Case Study Method” (“PCS Method”). We call for the creation of peer-reviewed journal-databases of pragmatic case studies as a foundational source of unifying applied knowledge in our discipline. As one example, the potential of the PCS Method for unifying different angles of theoretical regard is illustrated in an area of applied psychology, psychotherapy, via the case of Mrs. B. The article then turns to the broader historical and epistemological arguments for the unifying nature of the PCS Method in both applied and basic psychology.Peer reviewe
Dr. Edwin Wright Collection: Author Unknown
Get PDFNotes - The author relates several short stories about his neighbours including Alex McDonell, homesteading and life around Meanook and Athabasca (1 page
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe 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
Measurement of the ratio of branching fractions B(B0→K∗0γ )/B(B0s→φγ ) and the directCP asymmetry inB 0→K∗0γ
Get PDFThe ratio of branching fractions of the radiative B decays B0→K⁎0γ and B0s→ϕγ has been measured using an integrated luminosity of 1.0 fb−1 of pp collision data collected by the LHCb experiment at a centre-of-mass energy of s√=7TeV. The value obtained is
B(B0→K⁎0γ)B(B0s→ϕγ)=1.23±0.06(stat.)±0.04(syst.)±0.10(fs/fd),
where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is associated with the ratio of fragmentation fractions fs/fd. Using the world average value for B(B0→K⁎0γ), the branching fraction B(B0s→ϕγ) is measured to be (3.5±0.4)×10−5.
The direct CP asymmetry in B0→K⁎0γ decays has also been measured with the same data and found to be
ACP(B0→K⁎0γ)=(0.8±1.7(stat.)±0.9(syst.))%.
Both measurements are the most precise to date and are in agreement with the previous experimental results and theoretical expectations
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
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