1,720,958 research outputs found
Efecto de Prosopis flexuosa sobre las especies del sotobosque y su importancia para el manejo pastoril de los algarrobales del desierto del Monte Central
No full textIn the Monte Biogeographic Province, located
in the arid region of Argentina, the presence
of Prosopis flexuosa DC. produces spatial
heterogeneity through edaphic modifications and
microclimate changes. This results in vegetation
patches differing in species composition and
abundance. However, this interaction can be
modified by the occurrence of gradients of biotic
stress or disturbance intensity. In particular,
grazing has been observed to enhance or reduce
vegetation heterogeneity. Such complex of
interactions could determine forage availability for
cattle in one of the driest areas of the Monte Desert.
We assessed the effect of Prosopis on understory
species and analyzed whether the outcomes of this
interaction differed with distance to watering points,
as a proxy of grazing intensity, in the Northeast of
Mendoza Province, Argentina. We used a two-way
factorial design including the following factors:
1) microsite (under the cover of P. flexuosa trees
and in intercanopy microsites) and 2) distance
to watering points ("near the watering point",
500-700 m away, and "far from the watering
point", 3-4 km away). Cover of each species,
total cover, bare soil, and litter were recorded,
and plant diversity, richness, and evenness were
estimated with the modified Point Quadrat method.
Results showed that P. flexuosa cover, distance
from watering points, and the interaction between
them determined species composition, abundance
and spatial distribution of understory species, and
were, consequently, a determining factor for forage
availability. The presence of P. flexuosa enhances
carrying capacity by supporting higher abundance
of grasses under its canopy. Near watering
points, high grazing intensity appears to disrupt
the patches formed under P. flexuosa canopies,
reducing the differences between microsites.En la Provincia Biogeográfica del Monte,
ubicada en la zona árida de Argentina, la presencia
de Prosopis flexuosa DC. genera heterogeneidad
espacial a través de modificaciones edáficas y
cambios microclimáticos, lo que genera parches
de vegetación con distinta composición florística
y abundancia de especies. Sin embargo,
esta interacción puede ser modificada por la
presencia de gradientes de estrés biótico o
de intensidad de disturbio. En particular, se ha
observado que el pastoreo puede incrementar
o disminuir la heterogeneidad espacial. Este
complejo de interacciones puede determinar la
disponibilidad de forraje en una de las zonas
más áridas del Monte. Este estudio analiza la
influencia de P. flexuosa sobre el patrón espacial
del resto de las especies de la comunidad y
cómo esta interacción es modificada según
la distancia a la aguada, tomada como un
indicador de la intensidad de pastoreo, en el
Noreste de la Provincia de Mendoza, Argentina.
Fue realizado un diseño bifactorial, incluyendo
los siguientes factores: 1) micrositio ("bajo la
cobertura de P. flexuosa" y "áreas expuestas") y
2) distancia a la aguada ("cerca de la aguada",
desde 500 hasta 700 m, y "lejos de la aguada",
entre 3 y 4 km). Se registró la cobertura de
cada especie, cobertura total, suelo desnudo
y mantillo, y se estimó la diversidad, riqueza
y equitatividad a través del método de Point
Quadrat modificado. Los resultados muestran
que la cobertura de P. flexuosa, la distancia a la
aguada y la interacción entre ambas determinan
la composición, abundancia y distribución
espacial de las especies en la comunidad
y, consecuentemente, la disponibilidad de
forraje. La presencia de P. flexuosa aumenta
la capacidad de carga incrementando la
abundancia de pastos bajo su dosel, aportando
por lo tanto a la cobertura forrajera. Cerca de la
aguada, la alta intensidad ganadera disminuye
el efecto de P. flexuosa al disminuir la diferencia
entre los micrositios.Fil: Cesca, Erica M..
Instituto Argentino de Nivología, Glaciología y Ciencias AmbientalesFil: Villagra, Pablo.
Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Passera, Carlos B..
Instituto Argentino de Investigaciones de las Zonas Áridas Fil: Álvarez, Juan.
Instituto Argentino de Nivología, Glaciología y Ciencias Ambientale
Socioeconomic and spatial processes in the use of forest resources in Mendoza since the late nineteenth century to the mid-twentieth
Get PDFEn este estudio se apunta a describir e interpretar los procesos de uso de los bosques de algarrobo en Mendoza entre 1900 y 1942, asociados al proceso de modernización capitalista que se instaló en la provincia hacia fines de siglo XIX. Se analiza cómo en el marco de este nuevo modelo de acumulación, los ferrocarriles cumplieron un rol trascendental en torno al aprovechamiento intensivo del recurso forestal, como así la satisfacción de la demanda de madera de la industria
vitivinícola en auge y de una población urbana en franco ascenso, justamente como se desprende de lo expresado en el presente trabajo, realizado a partir de estadísticas ferroviarias y fuentes históricas. De esta manera, se aportan nuevas perspectivas socio-territoriales sobre dichos procesos ambientales, ampliando estudios anteriores. Con el aporte de información inédita y resaltando particularidades locales y territoriales, se reconstruyen algunos aspectos de la historia
ambiental regional de suma importancia para comprender los procesos de construcción de estos espacios.The present study aims to describe and interpret the processes of the algarrobo (Prosopis) woods use in Mendoza between 1900 and 1942, associated to the capitalist modernization process installed in the province at the turn of the 19th century. In this work we analyze how within the frame of this new accumulation model the railways accomplished a transcendental rol regarding the intensive use of the wood resource, also to satisfy the wood demanded by the increasing
wine industry as well as by an also growing urban population. This is inferred from the railway statistics and historical sources in which the paper is based. Therefor, we provide new socio - territorial perspectives over the mentioned environmental processes enlarging previous studies. By contributing unpublished information and stressing local and territorial particularities we rebuilt some aspects of the regional environmental history, extremely important for understanding the construction processes of such spaces.Fil: Rojas, Juan Facundo.
Instituto Argentino de Nivología, Glaciología y Ciencias AmbientalesFil: Prieto, María del Rosario.
Instituto Argentino de Nivología, Glaciología y Ciencias AmbientalesFil: Álvarez, Juan.
Instituto Argentino de Nivología, Glaciología y Ciencias AmbientalesFil: Cesca, Erica M..
Instituto Argentino de Nivología, Glaciología y Ciencias Ambientale
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
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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