1,720,989 research outputs found
Pollinator shortage and global crop yield
Full text linkFil: Garibaldi, Lucas Alejandro. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio Ecotono; Argentina.Fil: Aizen, Marcelo A. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio Ecotono; Argentina.Fil: Cunningham, Saul A. CSIRO Entomology; Australia.Fil: Klein, Alexandra M. University of California; USA.Fil: Klein, Alexandra M. University of Goettingen; Alemania.Fil: Aizen, Marcelo A. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.Fil: Aizen, Marcelo A. Instituto de Investigaciones en Biodiversidad y Medioambiente (INIBIOMA); Argentina.Fil: Garibaldi, Lucas Alejandro. Universidad de Buenos Aires (UBA). Facultad de Agronomía; Argentina.A pollinator decline caused by environmental degradation might be compromising the production of pollinator-dependent crops. In a recent article, we compared 45 year series (1961–2006) in yield, production, and cultivated area of pollinator-dependent and nondependent crop around the world. If pollinator shortage is occurring globally, we expected a lower annual growth rate in yield for pollinator-dependent than nondependent crops, but a higher growth in cultivated area to compensate the lower yield. We have found little evidence for the first “yield” prediction but strong evidence for the second “area” prediction. Here, we present an additional analysis to show that the first and second predictions are both supported for crops that vary in dependency levels from nondependent to moderate dependence (i.e. up to 65% average yield reduction without pollinators). However, those crops for which animal pollination is essential (i.e. 95% average yield reduction without pollinators) showed higher growth in yield and lower expansion in area than expected in a pollination shortage scenario. We propose that pollination management for highly pollinator-dependent crops, such us renting hives or hand pollination, might have compensated for pollinator limitation of yield
Incremental contribution of pollination and other ecosystem services to agricultural productivity: effects of service quantity and quality
No full textFil: Garibaldi, Lucas A. Universidad Nacional de Río Negro. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural. Río Negro, Argentina.Fil: Garibaldi, Lucas A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural. Río Negro, Argentina.Fil: Aizen, Marcelo A. Universidad Nacional del Comahue. Instituto de Investigaciones en Biodiversidad y Medioambiente. Río Negro, Argentina.Fil: Cunningham, Saul A. Australian National University. Australia.Fil: Harder, Lawrence. University of Calgary. Canada.Fil: Klein, Alexandra M. University of Freiburg. Alemania.
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
Services from plant-pollinator interactions in the Neotropics.
Full text linkFil: Garibaldi, Lucas Alejandro. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Laboratorio Ecotono; Argentina.Fil: Klein, Alexandra M. University of California; USA.Fil: Garibaldi, Lucas Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina.Fil: Klein, Alexandra M. University of Goettingen; Alemania.Fil: Muchhala, Nathan. University of Missouri; St. LouisFil: Motzke, Iris. Universidad de Berna; SuizaFil: Bravo Monroy, Liliana. Universidad de Reading; Reino UnidoFil: Olschewski, Roland. Instituto Federal Suizo para la Investigación de Bosques, Nieve y Paisaje; SuizaAgricultural systems are no longer evaluated solely on the basis of the food they provide, but also on their capacity to limit impacts on the environment, such as soil conservation, water quality and biodiversity conservation, as well as their contribution to mitigating and adapting to climate change. In order to cope with these multiple service functions, they must internalize the costs and benefits of their environmental impact. Payments for ecosystem services are hoped to encourage and promote sustainable practices via financial incentives. The authors show that while the principle is straightforward, the practice is much more complicated. Whereas scenic beauty and protection of water sources provide benefits to the local population, carbon sequestration and biodiversity conservation can be considered international public goods, rendering potential payment schemes more complex. Few examples exist where national or international bodies have been able to set up viable mechanisms that compensate agricultural systems for the environmental services they provide. However this book provides several examples of successful programs, and aims to transfer them to other regions of the world. The authors show that a product can be sold if it is clearly quantified, there exists a means to determine the service's values, and there is a willing buyer. The first two sections of the book present methodological issues related to the quantification and marketing of ecosystem services from agriculture, including agroforestry. The third and final section presents case studies of practical payments for ecosystem services and experiences in Central and South America, and draws some lessons learnt for effective and sustainable development of ecosystem services compensation mechanisms
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
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
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