1,720,964 research outputs found
Impact of climate change on agricultural productivity and food security in the Himalayas: A case study in Nepal
Full text linkThe paradigmatic Dudh Koshi basin laid at the toe of Mt. Everest is largely visited by tourists every year, and yet agricultural productivity and food security therein are at stake under climate change. Agricultural yield in the area recently decreased, and the question arose whether cropping at higher altitudes may help adaptation. We investigated here the present, and future (until 2100) patterns of productivity of three main rain-fed crops in the catchment (wheat Triticum L., rice Oryza L., and maize Zea Mais L.). We explored food security using a nutritional index, given by the ratio of the caloric content from our target cereals, to daily caloric demand. We preliminary investigated whether vertical extension of the cropped area may increase food security. We did so by (i) mapping crops area using remote sensing, (ii) setting up the agronomic model Poly-Crop, (iii) feeding Poly-Crop with downscaled outputs from global climate models, and (iv) projecting vertical land occupation for cropping, population projections, and nutritional requirements. We estimated crop yield and food security at half century (2040–2050), and end of century (2090–2100), against a control run decade CR (2003−2013), under constant land use, and projected land occupation. On average, specific wheat yield would decrease against CR by −25% (rice −42%, maize −46%) at 2100, with largely yearly variability for unchanged land use scenario. Under modified land use scenario, wheat yield would decrease by −38%, while rice and maize yield would improve, maize very slightly (−22%, and −45%, against CR) in response to occupation of higher altitudes than now. Our food security index would decrease under all scenarios (111% in 2010, 49% on average at 2050, under a population peak, and 51% at 2100), and become more variable, however with potential for adaptation by colonization of higher lands (75%, 62%, at 2050, 2100). Very large expansion of one cereal (i.e. maize), may make food security more unstable, as mostly depending on erratic yield of that cereal only
Competitività, Infrastrutture e Politiche di Crescita: l'Effetto Moltiplicativo della Prossimità alle Infrastrutture di Trasporto e sulla Performance delle Imprese
No full textLo studio si inserisce all’interno di un vivo dibattito di politica economica: porta migliori risultati investire direttamente nella competitività delle imprese o nello sviluppo delle risorse territoriali?
Per rispondere a questa domanda di ricerca, nell’articolo si analizzano gli effetti mediatori della dotazione infrastrutturale sugli impatti delle politiche a sostegno diretto delle imprese. Per farlo, si utilizza un approccio innovativo basato sulla determinazione mediante geo-codificazione delle posizioni di imprese ed infrastrutture.
Lo studio integra intuizioni, metodologie e tecniche da tre diversi filoni di letteratura scientifica che, finora, erano rimasti separati: gli studi sui fattori di condizionamento delle politiche regionali, quelli sull’impatto delle politiche a livello di impresa e sulle misure di localizzazione basate su micro-dati.
I risultati indicano che, al netto dell’importanza di entrambi gli ambiti di investimento pubblico, l’impatto e l’efficienza delle politiche di supporto diretto alle imprese varia di intensità a seconda del territorio e delle sue caratteristiche infrastrutturali. L’analisi mostra una chiara complementarità tra la presenza di infrastrutture e l’impatto delle politiche di assistenza alle imprese, complementarità che diventa ancor più rilevante per quei territori, quali il Mezzogiorno, meno dotati di infrastrutture
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
Automatic Co-registration of Copernicus Time Series via Synchronization
No full textThis paper presents a satellite image co-registration procedure aiming at simultaneously estimating multiple affine transformations between a set of multi-temporal or multi-source satellite images, reducing error accumulation and improving metric precision. The approach is based on synchronization, a method that seeks to infer the unknown states of a network of nodes, where only the ratio (or difference) between node pairs can be measured. In our case states represent affine transformations. The proposed method globally combines via synchronization pairwise transformations computed for all the image combinations of the multi-temporal sequence, beyond the traditional image-to-base approach available in remote sensing and GIS packages. Results obtained with Landsat and Sentinel-2 images reveal that the algorithm can be used not only to perform the actual co-registration, but also as a diagnostic tool to evaluate the quality of transformation parameters through a comparison with basic co-registration methods, as well as with global least squares adjustment
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
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
- …
