962 research outputs found

    LIGHT PROPAGATION THROUGH A TURBULENT CLOUD: COMPARISON OF MEASURED AND COMPUTED EXTINCTION

    Get PDF
    Remote sensing techniques used for measurement of atmospheric cloud properties operate under the notion that light extinction caused by scattering and absorption is exponential due to Beer-Lambert law. This is expected to be valid for a uni-form medium with no spatial correlations between particle position. The aim of this research was to show that under turbulent conditions, cloud droplets cannot be interpreted as non-correlated, and in turn will exhibit a lower than exponential light decay from scattering. The research took place at the MTU π-Chamber laboratory. A temperature difference between the floor and ceiling of the chamber was applied to create convection-driven turbulence. When turbulent cloud conditions were achieved, it’s optical depth properties was analyzed. This was done by deriving the optical depth by computational means through the acquisition of its droplet size distribution, and processing it through Mie scattering theory, while simultaneously acquiring direct measurement of optical depth using a Laser-Hygrometer. Results showed that there is a trend where larger temperature differences inside the chamber caused the direct extinction of light to deviate more strongly from the computed extinction. This less then exponential extinction parameter allows us to understand the significant effect that a turbulent cloud cover has on radar and satellite signals

    Advances in the etiology of sweet potato (Ipomoea batatas (L.) Lam) yellow curling disease in Argentina

    Get PDF
    Sweet potato yellow curling (YC), the most severe disease of sweet potato detected in Argentina, causes symptoms and damage to sweet potato crops in all cultivated regions. Since 2010/11, the presence of four viruses has been detected in symptomatic cv. Arapey INIA: two potyviruses non-persistently transmitted by Myzus persicae (sweet potato feathery mottle virus, SPFMV and sweet potato virus G, SPVG); a closterovirus, sweet potato chlorotic stunt virus (SPCSV) and a geminivirus, sweet potato leaf curl virus (SPLCV), both transmitted by Bemisia tabaci in a semi-persistent and persistent manner, respectively. All the plants were collected from fields in Colonia Caroya, Córdoba province, Argentina. The objectives of the present work are to isolate and identify the virus or viruses involved in YC disease of sweet potato, and to elucidate the viral combination that reproduces YC symptoms. The most severe YC symptoms for this genotype in the field were only reproduced by a combination of the four viruses. The symptoms include chlorosis, stunting, mosaic, blistering, leaf curling, chlorotic spots, chlorotic patterns, leaf area reduction and distortion, and upward curling of leaf edges. The presence of each virus was detected by serological (DAS, NCM and TAS-ELISA) and molecular (PCR) tests. It is concluded that the interaction of SPFMV, SPVG, SPCSV and SPLCV is needed for the development of YC symptoms.El encrespamiento amarillo (EA), la enfermedad más severa detectada en Argentina, causa síntomas y daños en cultivos de batata en toda la región productora. Desde 2010/11 se ha detectado la presencia de cuatro virus en plantas sintomáticas del cv. Arapey INIA recolectadas en lotes de Colonia Caroya, provincia de Córdoba. Los virus son sweet potato feathery mottle virus (SPFMV) y sweet potato virus G (SPVG), dos potyvirus transmitidos de forma no persistente por Myzus persicae; un closterovirus: sweet potato chlorotic stunt virus (SPCSV) y un geminivirus: sweet potato leaf curl virus (SPLCV), ambos transmitidos por Bemisia tacabi de manera semipersistente y persistente, respectivamente. Los objetivos de este trabajo fueron aislar e identificar el o los virus involucrados en la enfermedad EA de la batata y determinar la combinación de virus que reproduce la sintomatología de EA Solo la combinación de los cuatro virus permitió reproducir la sintomatología más severa del encrespamiento amarillo observada a campo en dicho genotipo. Los síntomas incluyen clorosis, achaparramiento, mosaico, ampollado, enrulado de la hoja, manchas cloróticas, diseños cloróticos, reducción y distorsión del área foliar, bordes de la hoja curvados hacia arriba. La presencia de cada uno de los virus se detectó mediante pruebas serológicas (DAS, NCM y TAS-ELISA) y moleculares (PCR). Se concluye que la interacción de SPFMV, SPVG, SPCSV y SPLCV es necesaria para el desarrollo de EA.Fil: Flamarique, Sofía Solange. Fondo para la Investigación Científica y Tecnológica; ArgentinaFil: Flamarique, Sofía Solange. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Vilanova Perez, Antonella. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Luque, Andres Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Luque, Andres Vicente. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Rodriguez Pardina, Patricia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Rodriguez Pardina, Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Di Feo, Liliana Del Valle. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Di Feo, Liliana Del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); Argentin

    Cassava common mosaic virus infection causes alterations in chloroplast ultrastructure, function, and carbohydrate metabolism of cassava plants

    Get PDF
    Cassava common mosaic virus (CsCMV) is a potexvirus that causes systemic infections in cassava plants, leading to chlorotic mosaic and producing significant yield losses. To date, the physiological alterations and the mechanism underlying biotic stress during the cassava–CsCMV compatible interaction remains unknown. In this study, we found that CsCMV infection adversely modified chloroplast structure and had functional effects on chloroplasts in source leaves during the course of viral infection. Extrusion of the chloroplast membrane with amoeboid-shaped appearance and disorganized grana stacks were observed in infected mesophyll cells. These alterations were associated with up to 35% reduction of relative chlorophyll content, and a decline of CO2 fixation (13.5% and 24.2% at 90 and 210 days after planting, respectively). The effects of CsCMV infection on the performance index on absorption basis dropped up to 37%. The analysis of chlorophyll a fluorescence showed a progressive loss of both oxygen evolving complex activity and “connectivity” within the tripartite system (core antenna-LHCII-reaction centre). Here, we report the latter phenomenon for the first time in a viral infection. The oxidative stress process was observed in CsCMV-infected plants (20.8% reduction of antioxidant capacity with respect to noninfected plants). Other effects of the pathogen included reduction of starch and maltose content in source leaves, and a significant increase (24.7%) of the sucrose:starch ratio, which indicates an altered pattern of carbon allocation. Our results suggest that CsCMV induces chloroplast distortion associated with progressive chloroplast function loss and diversion of carbon flux in source leaf tissue, leading to the loss of cassava tuber yield.Fil: Zanini, Andrea Alejandra. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Fisiología y Recursos Genéticos Vegetales; Argentina. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Estudios Agropecuarios. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Unidad de Estudios Agropecuarios.; ArgentinaFil: Di Feo, Liliana del Valle. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatología y Modelización Agrícola - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Fitopatología y Modelización Agrícola; ArgentinaFil: Luna, Dario Fernando. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Fisiología y Recursos Genéticos Vegetales; Argentina. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Estudios Agropecuarios. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Unidad de Estudios Agropecuarios.; ArgentinaFil: Paccioretti, Pablo Ariel. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatologia y Modelizacion Agricola. Grupo Vinculado Catedra de Estadistica y Biometria de la Facultad de Ciencias Agropecuarias de la Universidad Nacional de Cordoba Al Ufyma | Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Unidad de Fitopatologia y Modelizacion Agricola. Grupo Vinculado Catedra de Estadistica y Biometria de la Facultad de Ciencias Agropecuarias de la Universidad Nacional de Cordoba Al Ufyma.; ArgentinaFil: Collavino, Agostina Antonella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Formosa. Provincia de Formosa. Centro de Investigaciones y Transferencia de Formosa. Universidad Nacional de Formosa. Centro de Investigaciones y Transferencia de Formosa; ArgentinaFil: Rodriguez, Marianela Soledad. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Fisiología y Recursos Genéticos Vegetales; Argentina. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Estudios Agropecuarios. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Cordoba. Unidad de Estudios Agropecuarios.; Argentin

    Primer reporte de Sweet potato leaf curl virus en las provincias de Córdoba y Santiago del Estero de Argentina

    Get PDF
    La superficie con batata en Argentina experimentó notable reducción, causada por virosis que ocasionan daños en todas las regiones productoras, debido al intercambio indiscriminado de material de propagación y consiguiente ingreso de virus antes no citados, tales como los begomovirus de batata (sweepovirus), recientemente caracterizados en Bella Vista, Corrientes. En este trabajo, se analizaron secuencias parciales del genoma de dos aislamientos del Centro de Argentina, con las de uno previamente caracterizado en nuestro país (Bella Vista) y con las de otros begomovirus citados globalmente. Ambos aislamientos mostraron 97-99% de identidad de nucleótidos con Sweet potato leaf curl virus, de Bella Vista (JQ349087.1), por lo que según lo establecido por el International Committee on Virus Taxonomy (ICTV), ambos pertenecen a la misma raza. Sin embargo, es la primera vez que se caracteriza a este patogéno en la provincia de Córdoba y Santiago del Estero, Argentina; por lo que este trabajo es un aporte al esclarecimiento del complejo panorama de virosis en cultivo de batata en nuestro país.The surface with sweet potato in Argentina experienced a significant reduction produced by an important loss of yield due to virus diseases. The introduction of virus, such as sweepoviruses (sweet potato begomoviruses), is generally caused by the indiscriminate exchange of propagation material between different regions. In this paper we analyzed partial sequences of the genome of two begomovirus isolates collected in the Central región of Argentina. These sequences were compared with those of one previously characterized in our country (Bella Vista) (JQ349087.1), and with other begomoviruses cited globally. Both isolates showed 97-99% homology with Sweet potato leaf curl virus, Bella Vista, so that according to what is established by the International Committee on Virus Taxonomy (ICTV), both isolates belong to the same strain. However, this is the first time that this pathogen is characterized in Cordoba and Santiago del Estero, Argentina; so this work is a contribution to the elucidation of the complex panorama of viruses in of sweet potatoes crops in our country.Instituto de Patología VegetalFil: Martino, Julia Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales; ArgentinaFil: Di Feo, Liliana Del Valle. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Rodriguez Pardina, Patricia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; Argentin

    Geotechnical and geomechanical characterization of the fault gouge of the Alhama de Murcia active fault, SE Spain

    Get PDF
    Here we present the results of the mechanical and mineralogical study of the fault rock of the Alhama de Murcia fault. This fault is one of the most active faults in the Iberian Peninsula. It shows segments partially formed by exhumed fine grained fault rocks (fault gouge FG) with a thickness of more than 50 m developed mainly in a brittle regime. Several strength and strain tests have been carried out, both in-situ and in laboratory, considering different stress orientations in relation to the tectonic fabric. Undisturbed samples encountered from two fault observatory boreholes drilled near Lorca, (FAM-1 and FAMSIS-IGN, of 174 and 40 m depth, respectively) has been used for the laboratory tests. The FG shows a hard soil and soft rock like mechanical behavior with uniaxial compressive strength 1.19) for planes unfavourably oriente

    Etiología del encrespamiento amarillo de la batata en Argentina

    Get PDF
    El “encrespamiento amarillo”, una enfermedad detectada recientemente, causa síntomas y daños en cultivos de batata de todas las regiones cultivadas de la Argentina. En plantas del cv. Arapey INIA con síntomas evidentes de la virosis recolectadas en lotes de Colonia Caroya, Provincia de Córdoba desde la campaña 2010/11, pudo determinarse la presencia de dos potyvirus, Sweet potato feathery mottle virus y Sweet potato virus G, transmitidos de manera no persistente por áfidos (Myzus persicae), un crinivirus (Sweet potato chlorotic stunt virus) y un geminivirus (Sweet potato leaf curl virus), cuyo vector es la mosca blanca Bemisia tabaci (transmisión semipersistente y no persistente, respectivamente). El objetivo fue corroborar, a través del cumplimiento de los postulados de Koch, que las mencionadas entidades virales son los responsables de esta nueva patología. Sólo la combinación (injertos cuádruples de plantas del cv. Arapey INIA libres de virus con púas infectadas con cada uno de los virus mencionados) permitió reproducir la sintomatología más severa de “encrespamiento amarillo” observada en el campo en dicho genotipo: clorosis, achaparramiento, mosaico, ampollado, enrulado de la hoja, manchas cloróticas, diseños cloróticos, reducción y distorsión del área foliar, bordes de la hoja curvados hacia arriba. La presencia de cada uno de los virus en las plantas de batata injertadas fue determinada mediante pruebas serológicas (DAS- ELISA, NCM-ELISA y TAS-ELISA) y moleculares (PCR). Se concluye que la interacción de SPFMV, SPVG, SPCSV y SPLCV es suficiente para la manifestación del EA, si bien en cultivos de algunas regiones del país también se encontraron involucrados en la enfermedad otros dos geminivirus, un begomovirus: Sweet potato leaf curl Georgia virus y un mastrevirus: Sweet potato symptomless virus 1.Fil: Vilanova Pérez, A.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; ArgentinaFil: Flamarique, Sofia Solange. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; ArgentinaFil: Luque, Andres Vicente. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatología y Modelización Agrícola - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Fitopatología y Modelización Agrícola; ArgentinaFil: Rodriguez Pardina, P.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; ArgentinaFil: Di Feo, Liliana del Valle. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Unidad de Fitopatología y Modelización Agrícola - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Fitopatología y Modelización Agrícola; Argentina41º Congreso Argentino de HorticulturaLa PlataArgentinaAsociación Argentina de Horticultur

    Atherosclerotic Progression Attenuates the Expression of Nogo-B in Autopsied Coronary Artery: Pathology and Virtual Histology Intravascular Ultrasound Analysis

    Get PDF
    The relation of Nogo-B to atherosclerotic plaque progression is not well understood. Thus, the purpose of this study was to assess the expression of Nogo-B in fibroatheromas (FA) of different stages, classified using virtual histology intravascular ultrasound (VH-IVUS) analysis in 19 autopsied cases of non-sudden cardiac death. VH-IVUS imaging analysis was performed 30 mm from the ostium of each coronary artery. VH-IVUS revealed 11 early FAs (34.5±8.3 yr), 12 late FAs (42.6±16.6 yr), 8 thick-cap FAs (TkCFAs) (46.4±11.1 yr), and 6 thin-cap FAs (TCFAs) (51.8±6.8 yr). TkCFAs and TCFAs were defined as advanced FA. FA progression advanced with age (P=0.04). VH-IVUS analysis of small, early FAs showed smaller necrotic cores and relatively less calcium compared to more advanced FAs with large necrotic cores (P<0.001). Histopathology and immunohistochemical stains demonstrated that early or late FAs had smaller necrotic cores, less empty space of decalcification, and greater Nogo-B expression compared to advanced FAs (vs. early FA, P=0.013; vs. late FA, P=0.008, respectively). These findings suggest that FA progression is inversely associated with Nogo-B expression. Local reduction of Nogo-B may contribute to plaque formation and/or instability

    Identity-by-descent filtering as a tool for the identification of disease alleles in exome sequence data from distant relatives

    Get PDF
    Large-scale, deep resequencing may be the next logical step in the genetic investigation of common complex diseases. Because each individual is likely to carry many thousands of variants, the identification of causal alleles requires an efficient strategy to reduce the number of candidate variants. Under many genetic models, causal alleles can be expected to reside within identity-by-descent (IBD) regions shared by affected relatives. In distant relatives, IBD regions constitute a small portion of the genome and can thus greatly reduce the search space for causal alleles. However, the effectiveness of this strategy is unknown. We test the simulated mini-exome data set in extended pedigrees provided by Genetic Analysis Workshop 17. At the fourth- and fifth-degree level of relatedness, case-case pairs shared between 1% and 9% of the genome identical by descent. As expected, no genes were shared identical by descent by all case subjects, but 43 genes were shared by many case subjects across at least 50 replicates. We filtered variants in these genes based on population frequency, function, informativeness, and evidence of association using the family-based association test. This analysis highlighted five genes previously implicated in triglyceride, lipid, and cholesterol metabolism. Comparison with the list of true risk alleles revealed that strict IBD filtering followed by association testing of the rarest alleles was the most sensitive strategy. IBD filtering may be a useful strategy for narrowing down the list of candidate variants in exome data, but the optimal degree of relatedness of affected pairs will depend on the genetic architecture of the disease under study

    Nogo-B regulates migration and contraction of airway smooth muscle cells by decreasing ARPC 2/3 and increasing MYL-9 expression

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Abnormal proliferation, apoptosis, migration and contraction of airway smooth muscle (ASM) cells in airway remodeling in asthma are basically excessive repair responses to a network of inflammatory mediators such as PDGF, but the mechanisms of such responses remain unclear. Nogo-B, a member of the reticulum family 4(RTN4), is known to play a key role in arteriogenesis and tissue repair. Further studies are needed to elucidate the role of Nogo-B in airway smooth muscle abnormalities.</p> <p>Methods</p> <p>A mouse model of chronic asthma was established by repeated OVA inhalation and subjected to Nogo-B expression analysis using immunohistochemistry and Western Blotting. Then, primary human bronchial smooth muscle cells (HBSMCs) were cultured <it>in vitro </it>and a siRNA interference was performed to knockdown the expression of Nogo-B in the cells. The effects of Nogo-B inhibition on PDGF-induced HBSMCs proliferation, migration and contraction were evaluated. Finally, a proteomic analysis was conducted to unveil the underlying mechanisms responsible for the function of Nogo-B.</p> <p>Results</p> <p>Total Nogo-B expression was approximately 3.08-fold lower in chronic asthmatic mice compared to naïve mice, which was obvious in the smooth muscle layer of the airways. Interference of Nogo-B expression by siRNA resulted nearly 96% reduction in mRNA in cultured HBSMCs. In addition, knockdown of Nogo-B using specific siRNA significantly decreased PDGF-induced migration of HBSMCs by 2.3-fold, and increased the cellular contraction by 16% compared to negative controls, but had limited effects on PDGF-induced proliferation. Furthermore, using proteomic analysis, we demonstrate that the expression of actin related protein 2/3 complex subunit 5 (ARPC 2/3) decreased and, myosin regulatory light chain 9 isoform a (MYL-9) increased after Nogo-B knockdown.</p> <p>Conclusions</p> <p>These data define a novel role for Nogo-B in airway remodeling in chronic asthma. Endogenous Nogo-B, which may exert its effects through ARPC 2/3 and MYL-9, is necessary for the migration and contraction of airway smooth muscle cells.</p
    corecore