1,720,965 research outputs found
Alberi e pavimentazioni
Get PDFLa presentazione illustrerà gli effetti di una sperimentazione in corso dal 2011 finalizzata a studiare gli effetti di diverse tipologie di pavimentazioni sulla crescita e la fisiologia di due specie arboree, oltre che su alcuni parametri fisici del suolo. Verranno illustrate le principali problematiche derivanti dall'impermeabilizzazione del suolo e possibili metodo per porvi rimedio, tra cui pavimentazioni alternative e il verde urbano. Infine, sarà chiarito quali siano gli stress tipici che possono ridurre i servizi ecosistemici degli alberi in ambienti pavimentati
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
Improving transplant success: algae extracts and mycorrhiza
Get PDFTwo experiments were performed to evaluate if inoculation in the nursery with an algae extract or mycorrhiza can result in sturdy plants better able to tolerate transplant stress. Experiment 1 was conducted at the Ersaf forest nursery (Curno, BG, Italy). To test the hypothesis that algae extract can improve root growth and morphology, seeds of 5 woody species were seeded in containers using a growing media enriched with 0x, 1x, 2x and 3x the label dose (1 kg/m3) of a pure Ascophyllum nodosum extract. After germination, 6400 seedlings were arranged according to a randomized complete block design with 10 blocks and grown under nursery conditions for 2 years. Plant, root, stem, and leaf dry weights were monitored by destructive measurements. Total plant leaf area was measured by scanning all leaves with an A3 scanner and performing image analysis using ImageJ software. Total root length was measured using the root line intersect method. Specific root length was calculated as root length/root dry biomass. Leaf gas exchange and chlorophyll content were measured using an infra-red gas analyser and a spad-meter, respectively. All measurements were conducted on 2, 6, 12, 24, 48, and 72 weeks after germination. During the first growing season, biostimulants improved plant growth, root length, root density, net photosynthesis, and chlorophyll content only when applied at 3x label dose. Minor effects, instead, were observed on root-shoot ratio and stomatal conductance. Growth-improvements, however, were not confirmed in the second growing season. Results suggest that substrate amendment with Ascophyllum extracts may have short-term positive effects on plant and root growth, likely due to a nutritional boost. However, it failed to trigger structural changes in plant traits that can enhance transplant tolerance in the long run, as also observed in other studies conducted with commercial biostimulants or mycorrhiza inocula. Experiment 2 was conducted at Fondazione Minoprio (Vertemate con Minoprio, CO) to test the hypothesis that species-specific mycorrhizal inocula can improve transplant success in Acer campestre and Tilia cordata. Two-year seedlings were obtained from a local nursery into 0.4L containers and re-potted into 3L containers. At repotting, half of the plants were inoculated with species-specific mycorrhizal fungi, obtained through a controlled mycorrhization approach, while the remaining half was not inoculated. The inocula contained endo- (Acer) or both endo- and ecto- (Tilia) mycorrhizal fungi. Plants were grown under nursery conditions for two years (avoiding any fungicide treatment). Then, 144 plants (36 per species and treatment) were transplanted in an experimental field characterized by a loam soil according to a randomized complete block design with 6 blocks. Leaf gas exchange, water relations, and growth were measured for 34 months after transplant. Inoculated A. campestre showed higher survival and growth, and more favourable water relations and leaf gas exchange than non-inoculated plants after transplanting. By contrast, survival, growth and physiology of Tilia cordata were little affected by inoculation, because the inoculum failed to improve root mycorrhizal colonization after transplanting. The overall results suggest that nursery mycorrhizal inoculation can affect post-transplant performances, although its effectiveness depends on species
Foreste urbane : il ruolo degli alberi oltre l'estetica
No full textLa presentazione illustra alcuni dei principali servizi ecosistemici di regolazione ambientale offerti da alberi ed arbusti in città ed i risultati preliminari di una sperimentazione in corso dal 2018 finalizzata a quantificare tali benefici. Viene messo in luce come le Foreste Urbane possano rappresentare non solo elementi estetici ma potenziali mezzi di mitigazione e adattamento degli agglomerati urbani a inquinamento e cambiamenti climatici
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
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