1,721,103 research outputs found
From the last EuroPrevent towards the first ESC Preventive Cardiology Congress
No full textNo abstract availabl
Recupero di un impianto sperimentale di farnia soggetto a deperimento
No full textNella primavera del 2008, un grave deperimento è stato osservato in una piantagione di farnia,
messa a dimora nel 1989 dal Centro Nazionale per la Biodiversità Forestale di Peri in
collaborazione con l’Istituto Sperimentale per la Selvicoltura di Arezzo presso il campus
dell’Università di Parma. Il fenomeno ha portato nel giro di cinque anni alla morte di 227 individui
sui 1000 presenti. Nell’esame delle cause si è potuto escludere da subito l’effetto della siccità, per
la presenza di regolari irrigazioni. Le piante apparivano colonizzate da Biscogniauxia
mediterranea a cui rapidamente subentravano altri funghi lignicoli e numerosi insetti xilofagi. Dal
suolo si è potuto isolare Phytophthora quercina in prossimità delle piante sofferenti. Per
contrastare la moria fin dal 2009 si sono eseguite regolari concimazioni con pollina commerciale: i
risultati sono stati una forte riduzione della mortalità ed un buona ripresa vegetativa di piante già
sofferenti. Attualmente l’impianto appare in buono stato vegetativo anche se persistono alcune
piante sintomatiche. La possibilità di recuperare gli scopi sperimentali dell’impianto appare
concreta così come la sua possibile evoluzione verso una valenza socio ricreativa adatta al
contest
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
Mutation analysis of Lhca1 antenna complex. Low energy absorption forms originate from pigment-pigment interactions.
No full textThe light harvesting complex Lhca1, one of the four gene products comprising the photosystem I antenna system, has been analyzed by site-directed mutagenesis with the aim of determining the chromophore(s) responsible for its long wavelength chlorophyll spectral form, a specific characteristic of the LHCI antenna complex. A family of mutant proteins, each carrying a mutation at a single chlorophyll-binding residue, was obtained and characterized by biochemical and spectroscopic methods. A map of the chromophores bound to each of the 10 chlorophyll-binding sites was drawn, and the energy levels of the Q(y) transition were determined in most cases. When compared with Lhcb proteins previously analyzed, Lhca1 is characterized by stronger interactions between individual chromophores as detected by both biochemical and spectroscopic methods; most mutations, although targeted to a single residue, lead to the loss of more than one chromophore and of conservative CD signals typical of chlorophyll-chlorophyll interactions. The lower energy absorption form (686 nm at 100K, 688 nm at room temperature), which is responsible for the red-shifted emission components at 690 and 701 nm, typical of Lhca1, is associated with a chlorophyll a/chlorophyll a excitonic interaction originating from a pigment cluster localized in the protein domain situated between helix C and the helix A/helix B cross. This cluster includes chlorophylls bound to sites A5-B5-B6 and a xanthophyll bound to site L2
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
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