1,721,032 research outputs found
Uso de plaguicidas y estimación del costo en bienestar de regulaciones ambientales agrícolas.
No full textTesis presentada para optar al grado de Magíster en Economía de Recursos Naturales y del Medio Ambiente.El uso de plaguicidas es considerado un ejemplo típico de contaminación no puntual. Dados los problemas de información relacionados a dicho tipo de contaminación, la selección e implementación de políticas para su control es usualmente compleja. El objetivo de esta investigación consiste en estudiar el uso de plaguicidas y estimar el impacto en términos de costos en bienestar asociado a regulaciones de agrotóxicos en la cuenca hidrográfica del río Chillán (VIII Región, Chile). Utilizando la metodología propuesta por Sunding (1996), se obtiene una estimación del impacto económico en términos de costos en bienestar de la implementación de regulaciones ambientales agrícolas. Los tipos de regulaciones incluyen: a) sustitución de plaguicidas individuales, b) sustitución de grupos de plaguicidas, y c) restricción total de plaguicidas. En relación al uso de plaguicidas, los resultados obtenidos, muestran que 82% de los productores encuestados utilizan agrotóxicos como práctica habitual, siendo los meses de julio a septiembre los de mayor aplicación. Los herbicidas son el grupo de plaguicidas más utilizados en la zona de estudio, y finalmente, en relación a la fiscalización sobre el uso de plaguicidas, se detectó que 17% de los productores es fiscalizado fundamentalmente por organismos privados (IANSA) y estatales. En términos del impacto en costos del bienestar bruto de las políticas de regulación, se determinó que políticas consistentes en sustitución de los mismos generan un impacto estimado entre el 15,7 y 23,1% del valor bruto de la producción dependiendo del tipo de regulación y sistema productivo afectado. Adicionalmente, y de manera específica, el impacto en bienestar de una política de sustitución de herbicidas del grupo químico de las Triazinas, utilizados en maíz y frutales, ascendería a alrededor de $ 114,2 millones, lo que representa aproximadamente un 12% del valor bruto de producción de los sistemas involucrados. Desde el punto de vista de tecnológico el mayor impacto regulatorio se presenta en los sistemas de producción de secano. En términos de impacto distributivo se detectó que una política de cancelación de plaguicidas resulta en mayor desigualdad, cuando se compara con una política de sustitución individual.Facultad de Ciencias Económicas y AdministrativasDepartamento de EconomíaConcepció
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
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
Remaining in rural areas: towards a rural entrepreneur’s analysis framework
Full text linkThis research employs an empirical approach to understand aspects defining why young people remain in their rural territories. Utilising a rural region of Caldas, Colombia as a case study and based on an agricultural education program for entrepreneurship, information from 368 rural young people was obtained. The study explored a conceptual model shaped by four dimensions and 34 variables. Using a Probit method, we identify significant variables regarding permanence in rural areas. We identify 11 key variables that determine the categories of socio-demographic profile, profile of entrepreneur characteristics, and category of motivations and territory. Our study contributes to literature on rural entrepreneurship from an empirical approach. Additionally, we propose a new analytical framework to address major problems in agriculture and rural territories, particularly in developing countries, such as Latin America.
Highlights:
This paper proposes an analysis model of the rural entrepreneur, which seeks to understand the aspects that determine the interest of rural young people wanting to stay within their own rural territories.
The categories and variables determining the permanence of rural youth in their territory based on entrepreneurship can be divided into an internal environment such as the dimensions of the profile and skills for entrepreneurship, as well as an external environment based on what determines the territory as a motivational factor.
The model shows the relevance of the interrelation of dimensions and environments, as even when rural young people have entrepreneurial skills, there are other aspects that promote permanence in the territories.This research employs an empirical approach to understand aspects defining why young people remain in their rural territories. Utilising a rural region of Caldas, Colombia as a case study and based on an agricultural education program for entrepreneurship, information from 368 rural young people was obtained. The study explored a conceptual model shaped by four dimensions and 34 variables. Using a Probit method, we identify significant variables regarding permanence in rural areas. We identify 11 key variables that determine the categories of socio-demographic profile, profile of entrepreneur characteristics, and category of motivations and territory. Our study contributes to literature on rural entrepreneurship from an empirical approach. Additionally, we propose a new analytical framework to address major problems in agriculture and rural territories, particularly in developing countries, such as Latin America.
Highlights:
This paper proposes an analysis model of the rural entrepreneur, which seeks to understand the aspects that determine the interest of rural young people wanting to stay within their own rural territories.
The categories and variables determining the permanence of rural youth in their territory based on entrepreneurship can be divided into an internal environment such as the dimensions of the profile and skills for entrepreneurship, as well as an external environment based on what determines the territory as a motivational factor.
The model shows the relevance of the interrelation of dimensions and environments, as even when rural young people have entrepreneurial skills, there are other aspects that promote permanence in the territories
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
Redes de información y sistemas de innovación agrícolas: hacia un nuevo enfoque de la extensión rural local
No full textRural extension has evolved from a traditional linear approach, towards a systemic model that involves the participation of public and private actors, configuring innovation systems. In this systemic interaction, information network structures are formed where producers establish links with various actors, both local and external to the territory. From the analysis of these networks, it was possible to identify key actors, determining the roles of promoter of innovations, opinion leader, facilitator intermediary and broker intermediary. The identification of actors and their function allows the implementation of a rural extension model at a local scale.La extensión rural ha evolucionado desde enfoque lineal tradicional, hacia un modelo sistémico que involucra la participación de actores públicos y privados, configurando sistemas de innovación. En esta interacción sistémica se conforman estructuras de redes de información donde los productores establecen vínculos con diversos actores tanto locales como externos al territorio. A partir del análisis de estas redes, fue posible identificar actores clave, determinando los roles de promotor de innovaciones, líder de opinión, intermediario facilitador e intermediario bróker. La identificación de actores y su función, permite la implementación de un modelo de extensión rural a escala local
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