Abstract:

The aim of this study was to investigate the influence of copper (Cu) during in vitro maturation (IVM) on apoptosis and DNA integrity of cumulus cells (CC); and oocyte viability. Also, the role of CC in the transport of Cu during IVM was evaluated on oocyte developmental capacity. Damage of DNA was higher in CC matured without Cu (0 µg/dl Cu, P < 0.01) with respect to cells treated with Cu for cumulus–oocyte complexes (COCs) exposed to 0, 20, 40, or 60 µg/dl Cu). The percentage of apoptotic cells was higher in CC matured without Cu than in CC matured with Cu. Cumulus expansion and viability of CC did not show differences in COC treated with 0, 20, 40, or 60 µg/dl Cu during IVM. After in vitro fertilization (IVF), cleavage rates were higher in COC and DO + CC (denuded oocytes + CC) with or without Cu than in DO. Independently of CC presence (COC, DO + CC or DO) the blastocyst rates were higher when 60 µg/dl Cu was added to IVM medium compared to medium alone. These results indicate that Cu supplementation to IVM medium: (i) decreased DNA damage and apoptosis in CC; (ii) did not modify oocyte viability and cumulus expansion; and (iii) improved subsequent embryo development up to blastocyst stage regardless of CC presence during IVM.

Author affiliation: Rosa, Diana Esther. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Anchordoquy, Juan Mateo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina

Author affiliation: Anchordoquy, Juan Patricio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina

Author affiliation: Sirini, Matias Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina

Author affiliation: Testa, Juan Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina

Author affiliation: Mattioli, Guillermo Alberto. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina

Author affiliation: Furnus, Cecilia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina

Abstract:

This study was designed to evaluate changes on variables in blood, urine and water balance in horses in response to a single dose of electrolyte supplementation. The essay was conducted on a randomised 3×3 Latin Square design repeated over time, with three animals and three treatments: Treatment 1: control group (without supplementation); Treatment 2: supplementation with a medium dose of electrolytes composed of: 0.25 g of NaCl + 0.125 g of KCl + 0.05 g of CaCl + 0.025 g of MgCl per kg of BW; Treatment 3: supplementation with a high dose of electrolytes composed of: 0.625 g of NaCl + 0.3125 g of KCl + 0.125 g of CaCl + 0.0625 g of MgCl per kg of BW, equivalent to 2.5 times the medium dose of supplementation. The electrolytes were supplied through a nasogastric tube 4 h after the morning meal. The diet provided had a forage:concentrate ratio of 70:30, composed of coastcross hay and commercial concentrate, with an estimated consumption of 2% of body weigth (BW). Horses received 116 mg/kg of BW of commercial mineral salt mixed in the concentrate. Samples of blood, urine and digesta were collected over a 12 h period after supplementation for analysis of sodium, potassium, chloride, calcium and magnesium concentration. Water intake and urine output were also measured. Electrolytic supplementation enhanced (P<0.05) the water intake, water retention and urine output. Blood variables were not altered by electrolyte supplementation (P≯0.05). The supplementation also influenced the sodium and chloride excretion in urine (P<0.05). Urine physicochemical characteristics and the concentration of electrolytes excreted with time were significantly altered as a function of the electrolytes supplementation.

Author affiliation: Martins, J. A.. Universidade Federal Rural do Rio de Janeiro; Brasil

Author affiliation: Ramos, M. T.. Universidade Federal Rural do Rio de Janeiro; Brasil

Author affiliation: Miranda, A. C. T.. Universidade Federal Rural do Rio de Janeiro; Brasil

Author affiliation: Dimache, L. A. G.. Universidade Federal Rural do Rio de Janeiro; Brasil

Author affiliation: Silva, A. T.. Universidade Federal Rural do Rio de Janeiro; Brasil

Author affiliation: Azevedo, J. F.. Universidade Federal Rural do Rio de Janeiro; Brasil

Author affiliation: Oliveira, C. A. A.. Universidade Federal Rural do Rio de Janeiro; Brasil

Author affiliation: Silva, V. P.. Universidade Federal Rural do Rio de Janeiro; Brasil

Author affiliation: Trigo, Pablo Ignacio. Universidade Federal Rural do Rio de Janeiro; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Almeida, F. Q.. Universidade Federal Rural do Rio de Janeiro; Brasil

Abstract:

This study was designed to evaluate changes on variables in blood, urine and water balance in horses in response to a single dose of electrolyte supplementation. The essay was conducted on a randomised 3×3 Latin Square design repeated over time, with three animals and three treatments: Treatment 1: control group (without supplementation); Treatment 2: supplementation with a medium dose of electrolytes composed of: 0.25 g of NaCl + 0.125 g of KCl + 0.05 g of CaCl + 0.025 g of MgCl per kg of BW; Treatment 3: supplementation with a high dose of electrolytes composed of: 0.625 g of NaCl + 0.3125 g of KCl + 0.125 g of CaCl + 0.0625 g of MgCl per kg of BW, equivalent to 2.5 times the medium dose of supplementation. The electrolytes were supplied through a nasogastric tube 4 h after the morning meal. The diet provided had a forage:concentrate ratio of 70:30, composed of coastcross hay and commercial concentrate, with an estimated consumption of 2% of body weigth (BW). Horses received 116 mg/kg of BW of commercial mineral salt mixed in the concentrate. Samples of blood, urine and digesta were collected over a 12 h period after supplementation for analysis of sodium, potassium, chloride, calcium and magnesium concentration. Water intake and urine output were also measured. Electrolytic supplementation enhanced (P<0.05) the water intake, water retention and urine output. Blood variables were not altered by electrolyte supplementation (P≯0.05). The supplementation also influenced the sodium and chloride excretion in urine (P<0.05). Urine physicochemical characteristics and the concentration of electrolytes excreted with time were significantly altered as a function of the electrolytes supplementation.

Author affiliation: Martins, J.A.. Universidade Federal do Rio de Janeiro; Brasil

Author affiliation: Ramos, M.T.. Universidade Federal do Rio de Janeiro; Brasil

Author affiliation: Miranda, A.C.T.. Universidade Federal do Rio de Janeiro; Brasil

Author affiliation: Dimache, L.A.G.. Universidade Federal do Rio de Janeiro; Brasil

Author affiliation: Silva, A.T.. Universidade Federal do Rio de Janeiro; Brasil

Author affiliation: Azevedo, J.F.. Universidade Federal do Rio de Janeiro; Brasil

Author affiliation: Oliveira, C.A.A.. Universidade Federal do Rio de Janeiro; Brasil

Author affiliation: Silva, V.P.. Universidade Federal do Rio de Janeiro; Brasil

Author affiliation: Trigo, Pablo Ignacio. Universidade Federal do Rio de Janeiro; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Almeida, F.Q.. Universidade Federal do Rio de Janeiro; Brasil

Abstract:

Los minerales son nutrientes esenciales que representan un 5% del peso vivo en el bovino. Las carencias y desequilibrios de minerales en la nutrición animal afectan la producción, reproducción y la salud. El ganado lechero cumple una destacada función productiva dentro de la economía de la región central de Santa Fe, principal cuenca lechera Argentina. Se pudo observar p<0,05 para las variables Cu, Zn, Fe, Mg, Ca, Na y K en suero entre los valores de los distintos campos, debido al manejo nutricional distinto y en el caso del campo C a la presencia de animales de la cruza Holstein- Jersey que están más adaptados a las elevadas temperaturas y a la humedad de la región. En los tres establecimientos se evidenció hiponatremia durante el período de lactación y no se diagnostico anemia. A lo largo de los estados fisiológicos en los distintos campos, se observó heterogeneidad en la leche. Las grandes concentraciones de cinc en la composición mineral del pasto, antagoniza ante la presencia de altas concentraciones de hierro y molibdeno de la dieta, caso que se observo en el campo A. Los resultados obtenidos brindan información a los productores y profesionales asesores de tambos.

Minerals are essential nutrients that represent 5% of live weight in the bovine. Lacks and disorders of minerals in animal nutrition affect the production, reproduction and health. Dairy cattle performs an outstanding productive function in the economy of the central region of Santa Fe, which is the principal milkshed in Argentina. There were significant differences (p <0,05) for the variables Cu, Zn, Faith, Mg, Ca, Na and K in serum among the values of the different fields due to different nutritional management. In the case of field C it was due to the presence of animals of Holstein-Jersey crosses, which are more adapted to the high temperatures and the humidity of the region. In the three fields hiponatremia was evidenced during the period of lactation but anemia wasn’t diagnosed. During the physiologic states in the different fields, heterogeneity was observed in the milk. The big concentrations of zinc in the mineral composition of the grass, antagonizes with the presence of high iron concentrations and molybdenum in the diet, which was observed in field A. The results obtained offer information to the producers and professional advisors in dairy farms.

Universidad Nacional del Litoral

Abstract:

The occurrence of smectite-illite and smectite-chlorite minerals series was studied along a thick clay cap (~300 m) drilled in the Cerro Pabellón geothermal field (northern Andes, Chile). X-ray diffraction (XRD) and scanning electronic microscopy (SEM) were used to characterize the alteration mineralogy and clay mineral assemblages and their changes with depth. Cerro Pabellón is a high-enthalpy blind geothermal system, with a reservoir zone from ~500 m to 2000 m depth, with temperatures of 200-250°C. Three main hydrothermal alteration zones were identified: (1) argillic; (2) sub-propylitic, and (3) propylitic, with variable amounts of smectite, illite-smectite, chlorite-smectite, mixed-layer chlorite-corrensite, illite and chlorite appearing in the groundmass and filling amygdales and veinlets. Chemical and XRD data of smectites, I-S and illites show, with some exceptions, a progressive illitization with depth. The evolution of I-S with depth, shows a sigmoidal variation in the percentage of illite layers, with the conversion of smectite to R1 I-S at ~180-185°C. These temperatures are greater than those reported for other similar geothermal fields and might indicate, at least in part, the efficiency of the clay cap in terms of restricting the circulation of hydrothermal fluids in low-permeability rocks. Our results highlight the importance of a better understanding of clay-mineral evolution in active geothermal systems, not only as a direct (or indirect) way to control temperature evolution, but also as a control on permeability/porosity efficiency of the clay cap.

Author affiliation: Maza, S.N.. Universidad de Chile. Facultad de Ciencias Físicas y Matemáticas. Department of Geology and Andean Geothermal Center of Excellence; Chile

Author affiliation: Collo, Gilda. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina

Author affiliation: Morata, D.. Universidad de Chile. Facultad de Ciencias Físicas y Matemáticas. Department of Geology and Andean Geothermal Center of Excellence; Chile

Author affiliation: Lizana, C.. Universidad de Chile. Facultad de Ciencias Físicas y Matemáticas. Department of Geology and Andean Geothermal Center of Excellence; Chile

Author affiliation: Camus, E.. Universidad de Chile. Facultad de Ciencias Físicas y Matemáticas. Department of Geology and Andean Geothermal Center of Excellence; Chile

Author affiliation: Taussi, M.. Universita Degli Studi Di Urbino Carlo Bo; Italia

Author affiliation: Renzulli, A.. Universita Degli Studi Di Urbino Carlo Bo; Italia

Author affiliation: Mattioli, M.. Universita Degli Studi Di Urbino Carlo Bo; Italia

Author affiliation: Godoy, B.. Centro de Excelencia En Geotermia de Los Andes (cega); Chile

Author affiliation: Alvear, B.. Centro de Excelencia En Geotermia de Los Andes (cega); Chile

Author affiliation: Pizarro, M.. Universidad de Chile. Facultad de Ciencias Físicas y Matemáticas. Department of Geology and Andean Geothermal Center of Excellence; Chile

Author affiliation: Ramírez, C.. Enel Green Power Chile And Andean Countries; Chile

Author affiliation: Rivera, G.. Enel Green Power Chile And Andean Countries; Chile. Universidad de Chile. Facultad de Ciencias Físicas y Matemáticas. Department of Geology and Andean Geothermal Center of Excellence; Chile

Abstract:

Clay minerals are layered materials with a number of peculiar properties, which find many relevant applications in various industries. Since they are easily found everywhere, they are particularly attractive due to their economic viability. In the cosmetic industry, clay minerals are often used as excipients to stabilize emulsions or suspensions and to modify the rheological behavior of these systems. They also play an important role as adsorbents or absorbents, not only in cosmetics but also in other industries, such as pharmaceuticals. This reviewer believes that since this manuscript is presented as covering topical applications that include pharmaceuticals, some types of clay minerals should be considered as a potential material to be used as drug delivery systems. We review several applications of clay minerals to dermocosmetic products, relating them to the underlying properties of these materials and exemplifying with a number of clay minerals available in the market. We also discuss the use of clay minerals in topically-applied products for therapeutic purposes, specially for skin treatment and protection.

Author affiliation: Moraes, Jemima Daniela Dias. Federal University of São Paulo, Graduate Program in Translational Medicine, Medicine Department; Brasil

Author affiliation: Bertolino, Silvana Raquel Alina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina

Author affiliation: Cuffini, Silvia Lucia. Federal University of São Paulo, Graduate Program in Material Science Engineering; Brasil

Author affiliation: Ducart, Diego Fernando. University of Campinas - Unicamp, Institute of de Geosciences; Brasil

Author affiliation: Bretzke, Pedro Eriberto. University of Vale do Itajaí, Graduate Program in Pharmaceutical Science, Nucleus of Chemical-Pharmaceutical Investigations; Brasil

Author affiliation: Leonardi, Gislaine Ricci. University of Campinas, Faculty of Pharmaceutical Science; Brasil. Federal University of São Paulo, Graduate Program in Translational Medicine, Medicine Department; Brasil

Abstract:

Minerals affect the nutritional, rheological, and safety features of food products. Soybeans represent a good source of minerals. The objective of this study was to evaluate the effect of the environment on the variability of mineral elements in Argentinean soybeans in field experiments. Climatic variables (maximum, mean, and minimum air temperature; solar radiation; precipitation; and potential evapotranspiration) were recorded daily during the seed filling period; soil properties were also reported. Minerals in soybeans were determined by inductively coupled plasma?mass spectrometry. Selenium was determined by hydride generation coupled to an atomic absorption spectrophotometer. Molybdenum and selenium were significantly increased (over 100%) in soybeans grown at higher soil pH with high available molybdenum. Air temperature was the climatic variable that best predicted changes in the soybean seed mineral composition. Optimum weather conditions (OWC) were defined by thresholds of the climatic variables by regression trees for desirable mineral composition. Maximum and minimum daily air temperatures during the seed filling period (30.1 and 17.1°C, respectively) were the OWC for maximizing calcium, magnesium, and manganese contents. A maximum daily air temperature over 28.0°C resulted in higher iron and cobalt levels (p < 0.001). Maximum zinc content was observed when solar radiation exceeded 18.1 MJ m−2 during seed filling (p < 0.001). Results from this study showed variation in the mineral composition of soybeans. Environmental features during the seed filling period should be considered when desired mineral composition is expected in soybean according to the end uses.

Author affiliation: Marioli Nobile, Carla Georgina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Instituto de Tecnología Agroindustrial del Noroeste Argentino. Provincia de Tucuman. Ministerio de Desarrollo Productivo. Estación Exp.agroindustr. "obispo Colombres"(p). Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina

Author affiliation: Balzarini, Monica Graciela. Universidad Nacional de Córdoba. Facultad de Cs.agropecuarias. Departamento de Desarrollo Rural; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Aguate, Fernando Matías. Universidad Nacional de Córdoba. Facultad de Cs.agropecuarias. Departamento de Desarrollo Rural; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Grosso, Nelson. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Author affiliation: Soldini, Diego. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Marcos Juarez; Argentina

Author affiliation: Huawei, Zeng. Grand Forks USDA Human Nutrition Research Center; Estados Unidos

Author affiliation: Wen-Hsing, Chen. Dep. of Food Science. Nutrition and Health Promotion; Estados Unidos

Author affiliation: Martinez, Maria Jose. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Manfredi; Argentina

Abstract:

Author affiliation: Brem, J.J. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina.

Author affiliation: Ortiz, M.L. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina.

Author affiliation: Trulls, H.E. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina.

Author affiliation: Zach, A. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina.

Author affiliation: Brem, J.C. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina.

El 10% del ganado caprino de Argentina se cría en la región nordeste, bajo un sistema familiar agroforestal, con bajos índices de producción. Un mecanismo para lograr mayores impactos productivos es incorporar alguna tecnología de proceso, tal como el mejoramiento nutricional de la majada. La vinculación entre arbustos forrajeros y animales generalmente se practica en pequeños rumiantes conformando lo que se conoce como sistema agrosilvopastoril, el cual demostró ser socialmente deseable y económicamente viable. El contenido de minerales en el follaje de la planta de morera (Morus alba) es alto y hasta ahora no se han encontrado compuestos tóxicos ni factores antinutricionales. El objetivo del ensayo fue obtener información estacional del contenido de minerales en las hojas de moreras cultivadas en Corrientes (Argentina). Se comunican resultados de los análisis realizados en otoño, primavera y verano 2011-2012. La estación invernal fue excluida debido a la falta de crecimiento foliar de esta especie. Las muestras se secaron en estufa durante 36 horas a 56ºC, 12 horas a 105ºC y luego a 550ºC. Sobre las cenizas se determinaron concentraciones de calcio, magnesio, hierro, cobre, manganeso y cinc por espectrofotometría de absorción atómica. El fósforo inorgánico se determinó según técnica fotocolorimétrica del molibdato de amonio con lectura a 620 nm. Se presentan valores de tendencia central y dispersión obtenidos estacionalmente sobre 3 pools de muestras foliares homogeneizadas y tomadas a partir de 8 ejemplares existentes en el predio de cultivo. Se concluye que los valores de P, Fe y Mn son más bajos durante primavera y verano; el nivel de Ca disminuye en verano y otoño; el de Zn declina en otoño y los de Cu y Mg se mantienen constantes en las tres estaciones.

Ten percent of Argentina’s goat farming takes place in the northeast region of the country under farm-household system with low production rates. One mechanism for achieving greater impact on regional production is to incorporate some process technology such as nutritional enhancement of the flock. Linkage between fodder shrubs and animals has usually been used for small ruminants production, situation known as agroforestry system, considered desirable and economically viable. A high mineral content in leaves of Morus alba has been found. On the contrary, no toxic or anti-nutritional factors are present in the plant. The objective of this work was to obtain information regarding seasonal mineral content in the leaves of mulberry trees for the area of Corrientes, northeastern Argentina. We report the results of the analysis of the leaves samples gathered in fall, spring and summer from 2011 to 2012. Cold season was not considered for the assay as no foliar growth takes place during this time of the year. The samples were placed in a drying oven for 36 hours at 56°C, 12 hours at 105°C and then at 550ºC. Calcium, magnesium, iron, copper, manganese and zinc were determined from ashes dissolutions by atomic absorption spectrophotometry, and inorganic phosphorus by photocolorimetrical method with ammonium molybdate at 620 nm. We present average seasonal values and their dispersion from three main pools of homogenized leaf samples gathered from eight plants of the cultivation area. We conclude that during spring and summer lower values of P, Fe and Mn are present on the plants; Ca decreased in summer and autumn, as well as Zn but only in fall. Cu and Mg values remained constant for the three seasons.

Abstract:

Se caracterizó la composición química en la especie Tajibo Morado, (Tabebuia impetiginosa "Mart. ex DC) Standley, procedente de la Comunidad Campesina Ocho Hermanos, del Municipio Carmen Rivero Torrez, del Departamento de Santa Cruz de la Sierra, aplicando metodologías y protocolos normalizados (TAPPI). Se extrajeron 3 trozas de 30 cm de alto por cada árbol de muestreo, obteniéndose un total de 9 rodajas. Los resultados muestran una media de 45,22% de Celulosa, lignina 32,07% y hemicelulosa 22,69%, en los extractos con etanol-benceno fue de 2,27%. La valoración del contenido de humedad dio una media de 15,44% y un pH de 5,22. En ceniza se obtuvo un valor medio de 1,31%, los porcentajes de minerales fueron: fósforo 0,011%, calcio 0,22%, magnesio 0,12%, potasio 0,013%, sodio 0,060%. La determinación de nitrógeno tuvo una media de 0,47% y de proteínas 2,96%. A partir de los resultados obtenidos se puede inferir que la especie Tabebuia impetiginosa (Mart. ex DC) Standley presenta un potencial importante desde el punto de vista químico, para el aprovechamiento de residuos, pudiendo ser utilizada en la obtención de; pellets, briquetas, bioetanol, alimento para ganado, carbón, adhesivos entre otros derivados.

The chemical composition of Tabebuia impetiginosa (Mart. ex DC) Standley, was characterized by applying standard analytical methodologies (TAPPI). The species also known as Tajibo Morado was collected in the rural community "Ocho Hermanos" from the "El Carmen Rivero Torrez" county of the Santa Cruz Department in Bolivia. Three samples of 30 cm long were extracted for each tree affording a total of nine wood slices. The obtained results show an average of 45.22% of cellulose, 32.07% of lignine and 22.69% of hemicellulose, in the etanol-benzene extracts with 2.27%. The evaluation of the moisture contents gave an average of 15.44%; the pH was 5.22. The ashes afforded an average of 1.31% and the minerals were estimated as: phosphor 0.011%, calcium 0.22%, magnesium 0.12%, potasium 0.013%, sodium 0.060%. The nitrogen determination afforded the average valué of 0.47%. Finally, the proteins were in an average of 2.96%. As a conclusión we can infer that the species Tabebuia impetiginosa (Mart. ex DC) Standley has an important potential as a source for the exploitation of wood waste, as well as for the obtaining of: pellets, briquettes, bioethanol, cattle food, carbón, adhesive and other derivatives.

Author affiliation: Urrelo, David Fernando. Universidad Autónoma Gabriel Rene Moreno; Bolivia

Author affiliation: Leal, Laura Evelyn. Universidad Nacional de Salta. Facultad de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Bozo, Carmen. Universidad Autónoma Gabriel Rene Moreno; Bolivia

Abstract:

The distribution of the clay minerals of the Banco Negro Inferior-Río Chico Group succession (BNI-RC), a middle Danian–middle Eocene mainly continental epiclastic–pyroclastic succession exposed in the Golfo San Jorge Basin, extra-Andean Patagonia (∼46° LS), is assessed in order to determine the possible origin of clay and specific non-clay minerals using X-ray diffraction and scanning electron microscopy analyses. The control over the clay mineralogy of the sedimentary settings, contemporary volcanism, paleoclimate and weathering conditions is considered. A paleoclimatic reconstruction is provided and correlated with the main global warming events that occurred during the early Paleogene. Mineralogical analyses of BNI-RC demonstrate that smectite and kaolin minerals (kaolinite, halloysite and kaolinite/smectite mixed layers) are the main clay minerals, whereas silica polymorphs (volcanic glass and opal) are common non-clay minerals. Throughout the succession, smectite and kaolin minerals are arranged in different proportions in the three clay–mineral assemblages. These show a general vertical trend in which the smectite-dominated assemblage (S1) is replaced by the smectite-dominated assemblage associated with other clays (S2) and the kaolinite-dominated assemblage (K), and finally by S2 up-section. The detailed micromorphological analysis of the clay and non-clay minerals allows us to establish that the origins of these are by volcanic ash weathering, authigenic and pedogenic, and that different stages in the evolution of mineral transformations have occurred. The supply of labile pyroclastic material from an active volcanic area located to the northwest of the study area could have acted as precursor of the authigenic and volcanogenic minerals of the analyzed succession. Diverse fine-grained lithological facies (muddy and tuffaceous facies) and sedimentary settings (coastal swamp and transitional environments, and different fluvial systems) together with variable climate and weathering conditions controlled the mineralogical transformations and the arrangement of clay–mineral assemblages. The paleoclimatic reconstruction suggests a general warm and humid climate. However, the temporal trend of the clay–mineral assemblages, the ratios between smectite and kaolinite and the micromorphological analysis of clay minerals contrasted with evidence from sedimentological analyses suggest a warm and seasonal climate for the basal part of the unit, a warm and humid climate with a relatively more perennial rainfall regime in the middle part of the unit, and a warm and less humid, probably subhumid, climate up-section. Such a reconstruction makes it possible to establish a correlation with some of the hyperthermal events of the Early Paleogene Global Warming (EPGW) and, consequently, constitute one of the most complete time records of the EPGW in South America.

Author affiliation: Raigemborn, María Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; Argentina

Author affiliation: Gómez Peral, Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; Argentina

Author affiliation: Krause, Javier Marcelo. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Matheos, Sergio Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; Argentina