1,721,013 research outputs found
Vegetative propagation of Solidago canadensis from populations in Eastern Norway
Get PDFSolidago canadensis is a well-established invasive alien plant species in the lowlands and coastal areas from Østfold to Agder in Norway, with an expanding range. It spreads with small wind-dispersed seeds, and rhizomes. It is commonly found on cultivated land and road verges, where it alters the landscape and displaces native species.
Rhizomes and cuttings from S. canadensis were collected from three populations in Eastern Norway. The rhizomes and cuttings were planted in a pot experiment to examine their ability to propagate vegetatively, and thereby use this knowledge in managing their spreading. The rhizomes were buried at 0, 10 and 30cm, at two fragment lengths: 5 and 10cm. The cuttings were planted as 15cm stems, where the bottom 5cm where pushed into the soil. The experiment lasted from June 17th to August 12th. The probability of surviving, attaining a well-developed root system and attaining inflorescence for rhizomes was estimated statistically using ‘integrated nested Laplace approximations’ (INLA).
The results showed that increasing burial depth has a significant negative effect on rhizome survivability, although sprouting occurred at all burial depths. In addition, there was a significant difference in survivability between the populations. However, rhizome length did not have a significant effect on survivability. The number of aerial shoots had a significant positive effect towards attaining a well-developed root system, and the height of the tallest shoot increased with increasing root development. Many of the tallest shoots developed inflorescence, and the probability of inflorescence was estimated to be 90% at 600mm shoot length. The results suggest that if the rhizomes manage to sprout, they have a high likelihood of attaining a well-developed root system and thereby develop inflorescence.Solidago canadensis er en godt etablert fremmed invaderende planteart i lavlandet og kystområder fra Østfold til Agder, med økende utbredelsesområde. Den spres med små vindspredte frø, samt rhizomer. Den vokser vanligvis i kulturmark og langs veikanter, hvor den endrer tilstanden i landskapet og fortrenger stedegne arter.
Rhizomer og stiklinger fra S. canadensis ble samlet fra tre populasjoner i Øst-Norge. Rhizomene og stiklingene ble plantet i et potteeksperiment for å undersøke deres evne til vegetativ formering, i det øyemed å bruke denne kunnskapen til å begrense dens spredning. Rhizomene ble begravet på 0, 10 og 30cm, med to fragmentlengder: 5 og 10 cm. Stiklingene ble plantet som 15cm lange stengler, hvor de nederste 5cm ble dyttet ned i jorda. Eksperimentet varte fra 17. juni til 14. august. Sannsynligheten for å overleve, å oppnå et velutviklet rotsystem samt å oppnå blomstring for rhizomene ble estimert statistisk ved hjelp av ‘integrated nested Laplace approximations’ (INLA).
Resultatene viste at økende jorddybde hadde en signifikant negativ effekt på rhizomenes overlevelse, selv om spiring forekom på alle jorddybdene. Det var også en signifikant forskjell i overlevelse mellom populasjonene. Rhizomenes fragmentlengde viste seg å ikke ha noen signifikant effekt på overlevelse. Antallet overflateskudd hadde en signifikant positiv effekt på oppnåelsen av et velutviklet rotsystem, og høyden på det høyeste skuddet økte med økende rotutvikling. Mange av de høyeste skuddene utviklet blomstring, og sannsynligheten for blomstring ble estimert til å være 90% ved 600mm skuddlengde. Resultatene tyder på at dersom rhizomene klarer å spire, har de en høy sannsynlighet for å få et velutviklet rotsystem og dermed utvikle blomstring. M-P
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
Variations on the Author
Get PDF“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
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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