1,721,135 research outputs found
Disease data of Triphragmium ulmariae on Filipendula ulmaria in the Skeppsvik archipelago
No full textThe data set provides information on the incidence, prevalence and severity of a rust fungus Triphragmium ulmariae occurring in populations of the herbaceous perennial Filipendula ulmaria growing on a range of islands in the Skeppsvik archipelago, northern Sweden. These data, together with information on the size of individual host populations, has been used to monitor the impact of the disease on host population growth rates and temporal and spatial dynamics in a natural plant pathogen - host metapopulation system. See Zhan, J., Ericson, L., González-Jiménez, J. & Burdon, J.J. (202*). Disease affecting host population growth rates in a natural wild plant-pathogen association over a 30-year period. Journal of Ecology, accepted. And Smith, David L., Ericson, Lars & Burdon, Jeremy J. (2003) Epidemiological patterns at multiple spatial scales: an 11-year study of a Triphragmium ulmariae– Filipendula ulmaria metapopulation. Journal of Ecology 91 (5), 890-903. for further details
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
Environmental stresses mediate endophyte–grass interactions in a boreal archipelago
No full textSummary
1. Both evolutionary theory and empirical evidence from agricultural research support the view that asexual, vertically transmitted fungal endophytes are typically plant mutualists that develop high infection frequencies within host grass populations. In contrast, endophyte–grass interactions in natural ecosystems are more variable, spanning the range from mutualism to antagonism and comparatively little is known about their range of response to environmental stress.
2. We examined patterns in endophyte prevalence and endophyte–grass interactions across nutrient and grazing (from Greylag and Canada geese) gradients in 15 sites with different soil moisture levels in 13 island populations of the widespread grass Festuca rubra in a boreal archipelago in Sweden.
3. In the field, endophyte prevalence levels were generally low (range = 10–53%) compared with those reported from agricultural systems. Under mesic‐moist conditions endophyte prevalence was constantly low (mean prevalence = 15%) and was not affected by grazing pressure or nutrient availability. In contrast, under conditions of drought, endophyte prevalence increased from 10% to 53% with increasing nutrient availability and increasing grazing pressure.
4. In the field, we measured the production of flowering culms, as a proxy for host fitness, to determine how endophyte‐infected plants differed from uninfected plants. At dry sites, endophyte infection did not affect flowering culm production. In contrast, at mesic‐moist sites production of flowering culms in endophyte‐infected plants increased with the covarying effects of increasing nutrient availability and grazing pressure, indicating that the interaction switched from antagonistic to mutualistic.
5. A concurrent glasshouse experiment showed that in most situations, the host appears to incur some costs for harbouring endophytes. Uninfected grasses generally outperformed infected grasses (antagonistic interaction), while infected grasses outperformed uninfected grasses (mutualistic interaction) only in dry, nutrient‐rich conditions. Nutrient and water addition affected tiller production, leaf number and leaf length differently, suggesting that tillers responded with different strategies. This emphasizes that several response variables are needed to evaluate the interaction.
6. Synthesis. This study found complex patterns in endophyte prevalence that were not always correlated with culm production. These contrasting patterns suggest that the direction and strength of selection on infected plants is highly variable and depends upon a suite of interacting environmental variables that may fluctuate in the intensity of their impact, during the course of the host life cycle.Peer reviewedfinal article publishedantagonist–mutualist continuumwater stresssymbiosisSwedennutrient stressherbivorygrassFestuca rubraEpichloë festucaeendophyt
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
Hemmaproducerat foder ökad lönsamhet och klimatsmartare produktion
Full text linkÅterigen är det dags för Regionala jordbrukskonferensen för norra Sverige att slå upp portarna och hälsa välkommen till ett, som vi hoppas, intressant och lärorikt program. Detta är den 13:e konferensen sedan starten i mitten av 1970-talet. Konferensen har i år fokus på grödor som kan hjälpa oss att öka andelen hemmaproducerat foder. Stigande priser på världsmarknaden gör det inköpta fodret dyrare. Önskan om en mer resurssnål och miljövänlig produktion ställer krav på en större andel hemmaproducerat foder. Inom KRAV-produktionen finns kravet på 100 % ekologiskt. Vi tar även upp den så aktuella klimatfrågan, med fokus på odling och matproduktion. De posters som visas ger en översikt över olika projekt med inriktning på jordbruk i norr. Vi som står för arrangemanget är Stiftelsen lantbruksforskning (SLF), SLU, norrländsk jordbruksvetenskap och Regional Jordbruksforskning för norra Sverige (RJN)
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
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