44,551 research outputs found
The value of local community knowledge in species distribution modelling for a threatened Neotropical parrot
Get PDFSpecies distribution models are widely used in conservation planning, but obtaining the necessary occurrence data can be challenging, particularly for rare species. In these cases, citizen science may provide insight into species distributions. To understand the distribution of the newly described and Critically Endangered Amazona lilacina, we collated species observations and reliable eBird records from 2010–2020. We combined these with environmental predictors and either randomly generated background points or absence points generated from eBird checklists, to build distribution models using MaxEnt. We also conducted interviews with people local to the species’ range to gather community-sourced occurrence data. We grouped these data according to perceived expertise of the observer, based on the ability to identify A. lilacina and its distinguishing features, knowledge of its ecology, overall awareness of parrot biodiversity, and the observation type. We evaluated all models using AUC and Tjur R . Field data models built using background points performed better than those using eBird absence points (AUC = 0.80 ± 0.02, Tjur R = 0.46 ± 0.01 compared to AUC = 0.78 ± 0.03, Tjur R = 0.43 ± 0.21). The best performing community data model used presence records from people who were able recognise a photograph of A. lilacina and correctly describe its distinguishing physical or behavioural characteristics (AUC = 0.84 ± 0.05, Tjur R = 0.51± 0.01). There was up to 92% overlap between the field data and community data models, which when combined, predicted 17,772 km of suitable habitat. Use of community knowledge offers a cost-efficient method to obtain data for species distribution modelling; we offer recommendations on how to assess its performance and present a final map of potential distribution for A. lilacina. 2 2 2 2
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
Get PDFThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
Splitting hares: Current and future ecological niches predicted as distinctly different for two congeneric lagomorphs
Get PDFThe congeneric lagomorphs Lepus timidus and L. europaeus share allopatric distributions in many areas of Europe characterised by competitive exclusion and hybridisation. We investigated prospects for these species under climate change in northern England uplands. We created ensemble models predicting niche realisation for these species, influenced by abiotic and biotic factors, estimating niche overlap in geo-environmental space. The two species occupy distinctly different niches, influenced more by vegetation preferences than climatic differences. The current climate niche for L. timidus featured higher elevations with cooler temperatures and 168km2 range extent. Its current habitat niche scale was larger at 269km2 , comprised entirely of upland dwarf shrubs: heather, cotton grass, moorland grasses. By contrast, the current climate niche predicted L. europaeus occupying lowland areas with a milder climate and range extent of 252km2. Its current habitat niche was also greater, 401km2, being mostly improved grassland. Competition was presently limited. The current niche predictions showed very little geographic overlap between the species. Niche overlap measured by Schoener Index was low: current climate niche 0.16; current habitat niche 0.07. The future climate niches for 2050 (IPCC RCP2.6), predicted L. timidus range contracting to 19km2, on hilltops and L. europaeus range expanding to 765km2. Consequently L. timidus range would be wholly within the L. europaeus range. In many contact zones throughout Europe, L. europaeus outcompetes L. timidus; however, in the Peak District their distributions are largely distinct. Future replacement of L. timidus by L. europaeus may be engendered by dietary convergence, should a warmer climate cause a transition of upland dwarf shrub vegetation to grasses
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
Get PDFBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
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
Erratum to: Effect of moderate red wine intake on cardiac prognosis after recent acute myocardial infarction of subjects with Type 2 diabetes mellitus (Diabetic Medicine, (2006), 23, 9, (974-981), 10.1111/j.1464-5491.2006.01886.x)
No full textIn an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola.In an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola
Molecular structure of highly excited resonant states in Mg-24 and the corresponding Be-8+O-16 and C-12+C-12 decays
No full textExotic Be-8 and C-12 decays from high-lying resonances in Mg-24 are analyzed in terms of a cluster model. The calculated quantities agree well with the corresponding experimental data. It is found that the calculated decay widths are very sensitive to the angular momentum carried by the outgoing cluster. It is shown that this property makes cluster decay a powerful tool to determine the spin as well as the molecular structures of the resonances.Physics, NuclearSCI(E)7ARTICLE5null8
‹‹Una scherma amorosa››: Bufalino e il lettore
No full textIl saggio indaga le modalità con cui Bufalino indirizza e controlla a distanza il processo di lettura delle proprie opere, Congegnando un intrigante gioco di specchi, di rifrazioni e di mise en abyme, l’autore inserisce all’interno della narrazione episodi e apologhi allegorici, che compendiano in sé l’intero senso del racconto e mettono in scene figure di lettori. L’attenzione del lettore, messa in allerta dalle spie disseminate a bella posta nel testo, è convogliata spesso su una traiettoria per certi versi ‘obbligata’: muovendo dagli indizi predisposti con avvedutezza dal narratore l’interpretazione si concentra giocoforza su certi nodi significativi, mettendo da parte gli altri, eventuali spunti percorribili.The essay investigates the ways in which Bufalino directs and remotely controls the process of reading his own works. By assigning an intriguing game of mirrors, refractions and mise en abyme, the author inserts allegorical episodes and apologues into the narration, that summarize in themselves the whole sense of the story and bring together figures of readers. The attention of the reader, put on alert by the spies disseminated in the text, is often conveyed on a trajectory in some ways 'obliged': moving from the clues predisposed with shrewdness by the narrator the interpretation is concentrated on certain significant nodes, setting aside the others, any possible hints
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
Self-archiving practice and the influence of publisher policies in the social sciences
No full textAuthors in different disciplines exhibit very different behaviours on the so-called ‘green’ road to open access, i.e. self-archiving. This study looks at the self-archiving behaviour of authors publishing in leading journals in six social science disciplines. It tests the hypothesis that authors are self-archiving according to the norms of their respective disciplines rather than following self-archiving policies of publishers, and that, as a result, they are self-archiving significant numbers of publisher PDF versions. It finds significant levels of
self-archiving, as well as significant self-archiving of
the publisher PDF version, in all the disciplines
investigated. Publishers’ self-archiving policies have
no influence on author self-archiving practice
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