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The phenomenon of cavitation in grapevine… Unravelling implicated mechanisms = El fenómeno de la cavitación en vid… Descifrando los mecanismos implicados
Get PDFCavitation is a physiological dysfunction that takes place in the xylem of water stressed plants. It leads to a loss of hydraulic conductance (kL)as the vessels are filled with air. This impacts water supply, water potential (ΨL) and canopy hydration. Stomatal clossure is an effective response upon diminishing momentary or seasonal foliar hydraulic contents. Depending on each type of plant, stomata may close preventing catastrophic cavitations. This research intended to understand how stomatal control acts upon cavitation events in two contrasting grapevine varieties, Syrah and Grenache. A mechanistic was developed model based on the water and vapour fluxes, kL, stomata conductance (gs), and the vulnerability to cavitation of the xylematic tissue. The theoretical model explains how plants respond to drought and avoid catastrophic cavitation. Water stressed grapevines couple their gs with their kL in order to avoid embolism. It is not stomatal closure, by istself, the controlling mechanism. Grapevines under mild water stress, do not need to completely close their stomata in order to avoid cavitation, therefore, photosynthesis is not completely impeded, and the cost in terms of carbon assimilation is less than expected for other species.La cavitación es una disfunción fisiológica que ocurre en el xilema de las plantas bajo déficit hídrico, y que entraña una pérdida de su conductancia hidráulica (kL), cuando algunos vasos se llenan de aire. Esto incide negativamente sobre la oferta de agua y afecta el potencial hídrico foliar (ΨL) y la hidratación de la canopia. El cierre estomático es una respuesta efectiva ante la disminución del contenido hídrico. Dependiendo de la especie vegetal, los estomas suelen cerrase para evitar la cavitación catastrófica. Mediante un modelo mecanístico, que se construyó teniendo en cuenta los flujos de agua y vapor, las kL y conductancia estomática (gs), y la vulnerabilidad del xilema a cavitar; se probó que gs no es la única variable responsable de frenar la embolia. Se determinó que gs y kL están íntimamente asociadas y que este acople entre ambas conductancias es lo que frena la embolia. Se concluyó que, en la vid y bajo niveles de estrés hídrico moderado, no es necesario un cierre estomático para controlar la cavitación. Por esto, el mecanismo de control de la cavitación en la vid no conlleva un costo en términos de intercambio gaseoso.EEA MendozaFil: Hugalde, Ines Pilar. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Bonada, Marcos. South Australian Research & Development Institute; AustraliaFil: Vila, Hernan Felix. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentin
Recent advances in biocontrol and other alternative strategies for the management of postharvest decay in table grapes
No full textDuring postharvest, table grapes are often spoiled by molds. Aspergillus sp., Alternaria sp., Botrytis sp., Cladosporium sp. and Penicillium sp. are different mold genera frequently related to table grape rot. Fungal spoilage affects nutritional value and organoleptic properties while also producing health hazards, such as mycotoxins. Traditionally, synthetic fungicides have been employed to control fungal diseases. However, possible negative effects on health and the environment are a serious concern for consumers and government entities. This review summarized data on innovative strategies proposed to diminish postharvest losses and extend table grape shelf life. Among physical, chemical, and biological strategies, either alone or in combination, the integrated management of fungal diseases is a sustainable alternative to synthetic fungicides. However, to date, only a few alternative technologies have succeeded on a commercial scale. Recent research aimed at increasing the competitiveness of alternative technologies has led to the development of integrated management strategies to prevent postharvest decay and increase the safety and quality of table grapes.Fil: Torres Palazzolo, Carolina Andrea. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza; Argentina. Universidad Nacional de Cuyo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Ferreyra, Susana Gisela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Hugalde, Ines Pilar. Universidad Nacional de Cuyo; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Kuhn, Yamila Gisele. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Combina, Mariana. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Ponsone, Maria Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad Nacional de Cuyo; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza; Argentin
Studying growth and vigor as quantitative traits in grapevine populations
Get PDFVigor is considered as a propensity to assimilate, store, and/or use nonstructural carbohydrates for producing large canopies, and it is associated with high metabolism and fast growth. Growth involves cell expansion and cell division. Cell division depends on hormonal and metabolic processes. Cell expansion occurs because cell walls are extensible, meaning they deform under the action of tensile forces, generally caused by turgor. There is increasing interest in understanding the genetic basis of vigor and biomass production. It is well established that growth and vigor are quantitative traits and their genetic architecture consists of a big number of genes with small individual effects. The search for groups of genes with small individual effects, which control a specific quantitative trait, is performed by QTL analysis and genetic mapping. Today, several linkage maps are available, like “Syrah” × “grenache,” “Riesling” × “Cabernet Sauvignon,” and “Ramsey” × Vitis riparia. This last progeny segregates for vigor and constituted an interesting tool for our genetic studies on growth.EEA MendozaFil: Hugalde, Ines Pilar. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentina. University of California at Davis. Department of Viticulture and Enology; Estados UnidosFil: Riaz, Summaira. University of California at Davis. Department of Viticulture and Enology; Estados UnidosFil: Agüero, Cecilia B. University of California at Davis. Department of Viticulture and Enology; Estados UnidosFil: Vila, Hernan Felix. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Gomez Talquenca, Gonzalo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Walker, M. Andrew. University of California at Davis. Department of Viticulture and Enology; Estados Unido
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
A dynamic model for sodium intoxication unravels salt tolerance in grapevine (Vitis vinifera L.) rootstocks
Get PDFA correct selection of salt-tolerant plants should consider the relative effects of the various existing tolerance mechanisms. When toxic ions, like Na+, reach the leaves, they affect the photosynthetic apparatus, reducing plant growth and performance. Leaf concentration of toxic ions depends on exclusion efficiencies at root level, or compartmentation in organs other than leaves. On the other hand, flow within the plant depends on leaf area, transpiration rate, and soil ion concentrations. From this perspective, in a feedback process, leaf area may be, simultaneously, cause and consequence of salt toxicity. To unravel how this feedback process influences salinity damage in grapevines, a dynamic model of Na+ toxicity was developed. The theoretical model proposed a way to estimate plant exclusion and compartmentation efficiencies. Parametrization was based on a 60-days trial with potted cv. Malbec vines (Vitis vinifera L.), own-rooted and grafted onto 101-14Mgt, 1103P and Cereza, under three soil NaCl levels (0, 50 and 100 mM). The model simulated different grapevine rootstock responses to different salinity levels. These simulations evidenced the key role of Na+ exclusion in long-term tolerance. Stomatal adjustment, compartmentation and rootstock conferred vigor showed relatively minor effects.Una correcta selección de plantas tolerantes a la sal requiere una evaluación del peso relativo de los diferentes mecanismos de tolerancia. Cuando los iones tóxicos, como el
Na+, alcanzan el tejido foliar, causan lesiones en el aparato fotosintético, lo que afecta el crecimiento y el rendimiento de la planta. La concentración foliar de iones tóxicos depende de la eficiencia de la planta para excluir el flujo de iones tóxicos desde el suelo a nivel de la raíz, o para compartimentar estos iones en órganos distintos a las hojas. Por otro lado, el flujo de sustancias tóxicas dentro de la planta también depende, entre otros factores, del área foliar, la velocidad de transpiración y la concentración de los iones tóxicos en la solución del suelo. Desde esta perspectiva, en un proceso de retroalimentación, el área foliar puede ser simultáneamente una causa y consecuencia de la toxicidad de la sal. Para dilucidar cómo este proceso de retroalimentación influye en el daño por salinidad en las vides, se desarrolló un modelo dinámico de toxicidad para Na+. El modelo tuvo en cuenta este marco
teórico y propuso una forma de calcular las eficiencias de exclusión y compartimentación de tóxicos de la planta. Para parametrizar el modelo, se llevó a cabo un ensayo de 60 días de cv. Malbec (Vitis vinifera L.) a pie franco e injertadas en 101-14Mgt, 1103P y Cereza, bajo tres niveles de NaCl (0, 50 y 100 mM). El modelo se usó para simular el comportamiento de distintos portainjertos de vid bajo diferentes niveles de salinidad. Estas simulaciones nos permitieron comprender el papel clave de la exclusión de Na + en la tolerancia a la salinidad a largo plazo. El ajuste estomático, la compartimentación y el vigor conferido por el portainjerto mostraron menores efectos.EEA MendozaFil: Vila, Hernan Felix. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Di Filippo, Marina Laura. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Venier, Matias. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Cátedra de Química Agrícola; ArgentinaFil: Hugalde, Ines Pilar. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Filippini, Maria Flavia. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Cátedra de Química Agrícola; Argentin
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
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