Acaciapollenites acaciae sp. nov., una nueva políade de mimosoidea del neógeno, en la Cuenca del Colorado, Argentina

Fossil mimosoid polyads have been recently recovered from Neogene deposits in the Colorado Basin, Argentina, and the new species Acaciapollenites acaciae sp. nov. is described, which is closely similar to polyads of species included in Acacia Miller subgenus Acacia Vassal. It is characterized by colporate apertures on the distal face of the pollen grains, a typical polyad of the subgenus Acacia species. The new polyad species is very similar to those of the extant Acacia curvifructa Burkart. Comparing the habitat of subgenus Acacia extant species, the Acaciapollenites acaciae occurrence suggests drier and warmer paleoclimatic conditions than today for the Late Miocene-Early Pliocene in the Colorado Basin. Paleogeographic data of Acacia pollen diversity are discussed. A similar early diversification and distribution of Acacia genus is recognized for the new and old worldPolíades afines a Mimoisoideas fueron recuperadas de depósitos del Neógeno de la cuenca del Colorado, Argentina. Por sus detalles morfológicos es reconocida una nueva especie con afinidad botánica a las especies actuales del género Acacia, subgénero Acacia. Acaciapollenites acaciae sp. nov. se distingue por presentar aperturas colporadas sobre la superficie distal de sus granos de polen, políade típica de las especies del subgénero Acacia. La nueva especie de políade se compara con las de la especie actual Acacia curvifructa. Comparando el hábitat de las actuales especies del subgénero Acacia, la presencia de Acaciapollenites acaciae en el Neógeno de la cuenca del Colorado, sugiere condiciones paleoclimáticas mas áridas y cálidas que las de hoy día. Se discuten los datos paleogeográficos de la diversidad de Acacia. Es reconocida tanto para el nuevo como para el viejo mundo, una temprana diversificación y dispersión del género.Fil: Caccavari, Marta Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina. Universidad Nacional del Sur. Departamento de Geología; ArgentinaFil: Guler, Maria Veronica. Universidad Nacional del Sur. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Características palinológicas y fisicoquímicas de tres tipos de mieles uniflorales del centro de Argentina

Se estudiaron las características de 59 mieles monoflorales de Condalia microphylla Cav. (“piquillín”), Centaurea solstitialis L. (“abrepuño amarillo”) y Prosopis spp., provenientes de La Pampa, Argentina. Se determinaron caracteres polínicos (abundancia y frecuencia de tipos polínicos) y algunos parámetros fisicoquímicos (color, conductividad eléctrica, acidez libre, contenido de glucosa, relación glucosa-agua, humedad y pH). Se utilizaron dos tipos de análisis estadísticos: análisis de varianza de un factor y análisis multiJ T* -0.000aaaaléct.omponentes principales yléct.onglomer0aaa. Los análisis de varianza y multivariados permitieron distinguir las tres clases de mieles de acuerdo a las propiedades fisicoquímicaa. Las variables que mejor explicaron esta diferenciación fueron pH, conductividad eléctrica, color, glucosa y relación glucosaagua. El análisis polínico demostró que la frecuencia de polen tradicionalmente utilizada para definir una miel monofloral (> 45%) no es válido para las mieles estudiadas. Por ello, el análisis polínico relacionado con las propiedades físico-químicas mencionadas permitiría una adecuada clasificación en estas mieles monoflorales.The characteristics of 59 unifloral honeys of Condalia microphylla Cav. ("piquillín"), Centaurea solstitialis L. ("yellow starthistle") and Prosopis spp., from La Pampa, Argentina, were studied. Pollen features (abundance and frequency of pollen types) and some physicochemical parameters (colour, electrical conductivity, free acidity, glucose content, glucose: water ratio, moisture and pH) were determined. Two different but related sets of calculations were done: the first involved single-factor variance analysis, while the second set involved two multivariate methods, principal component analysis and cluster analysis. Variance and multivariate analysis allowed differentiation of the three honey types according to their physicochemical properties. The variables that best explained this differentiation were pH, electrical conductivity, colour, glucose content and the glucose:water ratio. Pollen analysis showed that the pollen frequency traditionally used (> 45%) for a botanical origin assignment in honey was not valid for the unifloral honeys studied. Therefore, pollen analysis should be combined with the above physicochemical analysis order to obtain a successful classification of these unifloral honeys.Fil: Naab, O.A.. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: Tamame, Maria Angelica. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: Caccavari, Marta Alicia. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentin

Características palinológicas y fisicoquímicas de tres tipos de mieles uniflorales del centro de Argentina

Se estudiaron las características de 59 mieles monoflorales de Condalia microphylla Cav. (“piquillín”), Centaurea solstitialis L. (“abrepuño amarillo”) y Prosopis spp., provenientes de La Pampa, Argentina. Se determinaron caracteres polínicos (abundancia y frecuencia de tipos polínicos) y algunos parámetros fisicoquímicos (color, conductividad eléctrica, acidez libre, contenido de glucosa, relación glucosa-agua, humedad y pH). Se utilizaron dos tipos de análisis estadísticos: análisis de varianza de un factor y análisis multiJ T* -0.000aaaaléct.omponentes principales yléct.onglomer0aaa. Los análisis de varianza y multivariados permitieron distinguir las tres clases de mieles de acuerdo a las propiedades fisicoquímicaa. Las variables que mejor explicaron esta diferenciación fueron pH, conductividad eléctrica, color, glucosa y relación glucosaagua. El análisis polínico demostró que la frecuencia de polen tradicionalmente utilizada para definir una miel monofloral (> 45%) no es válido para las mieles estudiadas. Por ello, el análisis polínico relacionado con las propiedades físico-químicas mencionadas permitiría una adecuada clasificación en estas mieles monoflorales.The characteristics of 59 unifloral honeys of Condalia microphylla Cav. ("piquillín"), Centaurea solstitialis L. ("yellow starthistle") and Prosopis spp., from La Pampa, Argentina, were studied. Pollen features (abundance and frequency of pollen types) and some physicochemical parameters (colour, electrical conductivity, free acidity, glucose content, glucose: water ratio, moisture and pH) were determined. Two different but related sets of calculations were done: the first involved single-factor variance analysis, while the second set involved two multivariate methods, principal component analysis and cluster analysis. Variance and multivariate analysis allowed differentiation of the three honey types according to their physicochemical properties. The variables that best explained this differentiation were pH, electrical conductivity, colour, glucose content and the glucose:water ratio. Pollen analysis showed that the pollen frequency traditionally used (> 45%) for a botanical origin assignment in honey was not valid for the unifloral honeys studied. Therefore, pollen analysis should be combined with the above physicochemical analysis order to obtain a successful classification of these unifloral honeys.Fil: Naab, O.A.. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: Tamame, Maria Angelica. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: Caccavari, Marta Alicia. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentin

Morphology and tructure of the pollen cone and pollen grain of the Araucaria species from Argentina

The pollen cone and the pollen grain of the two Argentinean species of Araucaria are described with LM, SEM and TEM. Primordia of pollen cones are formed in April and May and reach maturity by mid-October in A. angustifolia (Bert.) O. Kuntze and by mid-November in A. araucana. (Mol.) K. Koch. Characters of the mature pollen cones and microsporophylls between both taxa are clearly differentiated. Pollen grains are spheroidal-subspheroidal, inaperturate, and asaccate with granulate exine and a subequatorial annular area that corresponds to the sexine thickness. Sculpturing consists of irregularly dispersed granules that are sometimes fused to each other (A. angustifolia) or forming microrugulae (A. araucana). Microgranules and microspinules are also present. The pollen wall ultrastructure is formed by a granular ectexine and lamellated endexine. Granular elements in A. angustifolia are more loosely disposed, form more interstices, and are gradually smaller towards the endexine than in A. araucana. To asses the probable relationships within the family, we compared the pollen grains of the two Araucaria species with those of other extant genera (Agathis, Wollemia) and also with fossil pollen (Araucariacites, Balmeiopsis, Cyclusphaera, Dilwynites) attributed to Araucariaceae.Fil: del Fueyo, Georgina Marisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Caccavari, Marta Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; ArgentinaFil: Dome, Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentin

Diversidad polínica en el aire de Diamante (Entre Ríos, Argentina)

Se realizó el primer análisis aerobiológico de la atmósfera de Diamante (Entre Ríos, Argentina). Se presentan los resultados preliminares de un año de monitoreo, cuyos objetivos principales fueron: determinar la diversidad de la vegetación local y regional, y su dinámica fenológica. Los datos polínicos provienen de un muestreador volumétrico y continuo del tipo Hirst (Lanzoni), que permite obtener resultados comparables con el resto del mundo, además de su directa aplicación en medicina alergológica. Los tipos polínicos más abundantes fueron, en orden decreciente: Moraceae (con 60% del polen total anual, PTA), Poaceae, Cupressaceae, Fraxinus, Salix, Asteraceae Asteroideae, Celtis, Ambrosia, Artemisia, Urticaceae y Cyperaceae. Cada uno de estos taxones alcanzó al menos 2% del PTA. Sin considerar a Moraceae, los taxones anteriores más Platanus, reúnen el 76% del PTA. La relación entre el polen y la temperatura fue positiva, y entre el polen y las humedad relativa fue negativa. Se discute si existe una representación diferencial de las especies nativas (regionales) en relación a las plantas exóticas (locales), y la posibilidad de un transporte de media o larga distancia.The first aerobiological survey of Diamante atmosphere (Entre Ríos, Argentina) was performed. We present here the preliminary results of one year analysis whose main objective was to determine the diversity of local and regional vegetation and the dynamics of floral phenology. Pollen data were obtained with a continuous, and volumetric methodology using a Hirst type sampler (Lanzoni), which allows the aerobiologic comparison with any site around the world, besides of its direct application in allergological medicine. The most abundant pollen types in the air in decreassing order of importance were: Moraceae (with 60% of the annual total pollen, ATP), Poaceae, Cupressaceae, Fraxinus, Salix, Asteraceae Asteroideae, Celtis, Ambrosia, Artemisia, Urticaceae and Cyperaceae. Each one of these taxa reached at least 2% of the ATP. If Moraceae is not considering, all the above taxa including Platanus account for 76% of ATP. Relationship between pollen and temperature was positive, and between pollen and humidity was negative. It is discussed if it exists differential representativity of the native species (regional) in relation to exotics ones (local) in the pollen spectrum, and the possibility of transport from medium or long distances.Fil: Latorre, Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Caccavari, Marta Alicia. Provincia de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Universidad Autónoma de Entre Ríos. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción; Argentin

Remoción química como nueva alternativa a la remoción mecánica para el estudio del polen transportado en las escopas de abejas silvestres

255-262Taxonomic recognition and quantification of the different pollen types collected by bees offer the most direct method to study the diet. To determine the importance of each plant taxon, it is necessary to separate the pollen deposited only in the collecting structures in order to minimize contamination of grains collected passively in other parts of the body. The technique currently applied is based on the mechanical removal of the pollen loads with dissecting needles and repeated washings with ethanol. Metathoracic scopae that underwent this procedure showed traces of pollen in varying amounts when observed under the microscope. As an alternative to this technique chemical removal using HOK is proposed. The leg is removed and treated separatedly to avoid contamination. The deflocculant properties of HOK successfully allowed to separate the pollen adhered to the scopae, which can be then returned to the individual, unaffected by the procedure. Suspend the pollen in a know quantity of mounting fluid permit take the subsamples and determine the total number of pollen grains of each taxon. In this paper, the new technique is presented and its effectiveness is compared to the technique currenty used

Remoción química como nueva alternativa a la remoción mecánica para el estudio del polen transportado en las escopas de abejas silvestres

255-262Taxonomic recognition and quantification of the different pollen types collected by bees offer the most direct method to study the diet. To determine the importance of each plant taxon, it is necessary to separate the pollen deposited only in the collecting structures in order to minimize contamination of grains collected passively in other parts of the body. The technique currently applied is based on the mechanical removal of the pollen loads with dissecting needles and repeated washings with ethanol. Metathoracic scopae that underwent this procedure showed traces of pollen in varying amounts when observed under the microscope. As an alternative to this technique chemical removal using HOK is proposed. The leg is removed and treated separatedly to avoid contamination. The deflocculant properties of HOK successfully allowed to separate the pollen adhered to the scopae, which can be then returned to the individual, unaffected by the procedure. Suspend the pollen in a know quantity of mounting fluid permit take the subsamples and determine the total number of pollen grains of each taxon. In this paper, the new technique is presented and its effectiveness is compared to the technique currenty used

Temporal and spatial modulation of Rho GTPases during in vitro formation of capillary vascular network. Adherens junctions and myosin light chain as targets of Rac1 and RhoA

Endothelial cells (ECs) self-organize into capillary networks when plated on extracellular matrix. In this process, Rho GTPases-mediated cytoskeletal dynamics control cell movement and organization of cell-to-matrix and cell-to-cell contacts. Time course analysis of RhoA and Rac1 activation matches specific morphological aspects of nascent pattern. RhoA-GTP increases early during EC adhesion and accumulates at sites of membrane ruffling. Rac1 is activated later and localizes in lamellipodia and at cell-to-cell contacts of organized cell chains. When ECs stretch and remodel to form capillary structures, RhoA-GTP increases again and associates with stress fibers running along the major cell axis. N17Rac1 and N19RhoA mutants impair pattern formation. Cell-to-cell contacts and myosin light chains (MLC) are targets of Rac1 and RhoA, respectively. N17Rac1 reduces the shift of beta-catenin and vascular endothelial cadherin to Triton X-100-insoluble fraction and impairs beta-catenin distribution at adherens junctions, suggesting that Rac1 controls the dynamics of cadherin-catenin complex with F-actin. During the remodeling phase of network formation, ECs show an intense staining for phosphorylated MLC along the plasma membrane; in contrast, MLC is less phosphorylated and widely diffused in N19RhoA ECs. Both N17Rac1 and N19RhoA have been used to investigate the role of wild type molecules in the main steps characterizing in vitro angiogenesis: (i) cell adhesion to the substrate, (ii) cell movement, and (iii) mechanical remodeling of matrix. N17Rac1 has a striking inhibitory effect on haptotaxis, whereas N19RhoA slightly inhibits EC adhesion and motility but more markedly Matrigel contraction. We conclude that different Rho GTPases control distinct morphogenetic aspects of vascular morphogenesis

The Extreme Space Weather Event in 1903 October/November: An Outburst from the Quiet Sun

While the Sun is generally more eruptive during its maximum and declining phases, observational evidence shows certain cases of powerful solar eruptions during the quiet phase of the solar activity. Occurring in the weak Solar Cycle 14 just after its minimum, the extreme space weather event in 1903 October -- November was one of these cases. Here, we reconstruct the time series of geomagnetic activity based on contemporary observational records. With the mid-latitude magnetograms, the 1903 magnetic storm is thought to be caused by a fast coronal mass ejection (~1500 km/s) and is regarded as an intense event with an estimated minimum Dst' of ~-513 nT The reconstructed time series has been compared with the equatorward extension of auroral oval (~44.1{\deg} in invariant latitude) and the time series of telegraphic disturbances. This case study shows that potential threats posed by extreme space weather events exist even during weak solar cycles or near their minima.Comment: 20 pages, 5 figures, 1 table, and accepted for publication in the ApJ