An Improved Method for Obtaining Small Pressed Powder Pellets for the Analysis by XRF

A rapid, very low cost of instrumentation and simple approach to specimen preparation for the analysis by X-ray fluorescence spectrometry is presented. This technique requires a few mg of powdered samples, which are compressed to produce pellets. This procedure is employed for determining major, minor and trace elements in muscovites and K-feldspars. Factors affecting measured intensities, such as particle size and distribution, surface texture, pelletizing pressure, etc, are considered. A description of the new sample preparation device, including technical characteristics, is also given. It is demonstrated that suitable specimen presentation to the X-ray beam is obtained by using our procedure.Fil: D`angelo, José Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Strasser, Edgardo. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; ArgentinaFil: Marchevsky, Eduardo Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Química de San Luis. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Química de San Luis; ArgentinaFil: Perino, Ernesto. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentin

Chemotaxonomic comparison of the seed ferns Odontopteris cantabrica and Odontopteris schlotheimii, Middle Pennsylvanian Sydney Coalfield, Canada

We present the first comparative spectrochemical data in the study history of Odontopteris schlotheimii Brongniart, 1828–1831 and Odontopteris cantabrica Wagner, 1969. These fossils co-occur in the shaley roof of the Lloyd Cove seam (Ro% = 0.65; Sydney Coalfield, Canada). Fourier transform-infrared spectra show that the sampled pinnules of both species are preserved as fossilized-cuticles. They are prominently aliphatic with distinct methylene and methyl peaks (at 2922 cm–1 and 2852 cm–1); with relatively high contents of carbonyl groups (peaks at 1700 cm–1) that indicate a high degree of molecular cross linking; and with smaller amounts of aromatics (peaks at 820 cm–1 and 750 cm–1) with a low condensation degree of benzene rings. No differences among respective pinnules are inferred from the 3D chemometric model and associate significance tests by the analysis of variance (α = 0.05). At the same time, this method provides new, chemical parameters that, in conjunction with morphological features, could be used to efficiently distinguish species.Fil: D`angelo, José Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentina. Cape Breton University; CanadáFil: Zodrow, Erwin L.. Cape Breton University; Canad

Sterile foliage of fertile Sydneia manleyi and synangial chemistry (eusporangiate fern, Late Asturian, Canada): A new subfamily Sydneideae

Typification of Sydneia manleyi Psenicka et al. 2003 is based entirely on fertile foliage. Of late,attached sterile-fertile segments have been found which are illustrated and described, together with cuticular preparations. A new subfamily, Sydneideae subfam. nov. is erected for the monotypytic species. The synangial chemistry is compared with marattialean  synangia/sporangia from the Czech Republic and from Canada.Fil: Psenicka, Josef. West Bohemian Museum in Pilsen. Palaeontological Department; República ChecaFil: Zodrow, Erwin L.. Cape Breton Universit. Palaeobiology Laboratory; CanadáFil: D` Angelo, José Alejandro. Cape Breton Universit. Palaeobiology Laboratory; Canadá. Consejo Nacional de Investigaciones Científicas y Técnicas. Científico Tecnológico Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentin

The Neuropteris ovata frond and its cyclopteroids: Micromorphology-spectrochemistry-fractal taxonomy. Propositions for restructuring and taxonomy (Pennsylvanian, Canada)

The primary study material consists of the 65-cm frond Neuropteris ovata (Hoffmann) var. simonii, associate petiole with organically attached cyclopteroid leaflets and trunk. Ancillary N. ovata material is used, all from the Asturian-Cantabrian strata of the Sydney Coalfield, Canada. This material is appropriate for the objective of the study to present an ovata-frond Aufbau in terms of micromorphology coupled with chemistry using an holistic sampling design (co-ordinating epidermal microscopy with chemistry per sample location). Chemical analyses were obtained by the reliable FTIR technique (Fourier transform infrared spectroscopy) and interpreted via chemometrics by methods of principal component analysis. Fractal geometry is introduced as a promising taxonomic parameter. The main conclusions include that the N. ovata plant can be characterized by three distinct epidermal structures: (1) rectangular elongate (trunk and petiole), (2) elongate (rachides of three orders), and (3) undulate (pinnule), which to a certain extent agrees with the chemistry of the frond Aufbau. The frond was also complex - architecturally, histologically, physiologically, chemically and autecologically. It was photosynthetic, had secretory organs (implying a characteristic plant aroma), supporting rodlets, divers epicuticular features, and a distinct chemical composition/structure. The frond was likely 4 m long with complex-pinnate cyclopteroid leaflets, fimbriate or entire-margined, below and above the main bifurcation, which begs the question of cyclopteroid definition and function. The overall results will be beneficial to taxonomy/systematics, and guide pteridospermous reconstruction into a new paradigm.Fil: Zodrow, E. L.. Cape Breton University; CanadáFil: D`angelo, José Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Cleal, C.. National Museum Wales; Reino Unid

3D chemometric model simulating the Acitheca polymorpha frond: implications for reconstructing carboniferous ferns (Marattiales, Canada)

Reported are results of an initial approximate imitation of a Carboniferous fern frond, i.e., marattialean Acitheca polymorpha (Schimper), Middle Pennsylvanian Sydney Coalfield, Canada. The simulation experiment is based on the analysis of 14 infrared spectra obtained by means of Fourier Transform Infrared spectroscopy from four detached fragments of sterile polymorphic penultimate-pinna compressions. The calculated relative, semi-quantitative, chemical data from the infrared spectra are the input for principal component analysis deriving a 3D (three-dimensional) chemometric model. To interpret it, the four specimens are placed in hypothetical-frond positions simulating a tripinnate frond, based on diminishing penultimate-rachial widths from 1-mm (distal) to 10-mm (proximal). Hypothetical conclusions include position-dependent chemistries, specifically that of opposing trends of aromaticity vs. aliphaticity in pinnules-rachises. This, in turn, would suggest potential for (i) fern-frond reconstruction, and (ii) for determination of a most likely frond position of fragmentary specimens by “chemical classification”; the predictive aspect. However, further experimental refinement is necessary particularly based on larger frond segments to confirm or disconfirm the overall hypothetical results.Fil: D`angelo, José Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Cape Breton University; CanadáFil: Zodrow, Erwin L.. Cape Breton University; CanadáFil: Psenicka, Josef. West Bohemian Museum ; República Chec

SEM-EDS characterization of pyroclastic and opaque inclusions of Viluco pottery, Mendoza, Argentina

Realizamos una aproximación exploratoria a la caracterización por SEM-EDS de las inclusiones de 10 fragmentos de cerámica Viluco recuperados de contextos datados entre el siglo XV y XVII del norte de Mendoza y dos tiestos producidos durante la dominación incaica procedentes de un alero precordillerano mendocino (Centro Oeste argentino). Analizamos inclusiones piroclásticas y otras ricas en Fe, para conocer su microestructura y composición química (semicuantitativa). Los resultados permiten documentar sobre algunas de las tecnologías y posibles fuentes de materias primas usadas por las poblaciones locales de Mendoza en un período que abarca la dominación incaica y los primeros años de la colonia.Results of a pilot study are reported on in which SEM-EDS was used to characterize inclusions in Late Agroceramic Period ceramic fragments from the north of Mendoza (Center West of Argentina). Ten Viluco pottery fragments were analyzed that had been recovered from piedemonte zone contexts dated between 1400 and 1700, and two samples from Inca tambos recovered from a cave in the pre-Cordillera. Pyroclastic inclusions and others rich in Fe were the focus of study; both their microstructure and their chemistry were characterized (the latter was determined semi-quantitatively). The results document technologies and ceramic resource choices made by local potters during the period of Inca domination and the early Colonial period.Fil: Prieto Olavarría, Cristina Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Científico Tecnológico Mendoza. Instituto Argentino de Nivologia, Glaciologia y Ciencias Ambientales; Argentina. Universidad Nacional de Cuyo. Facultad de Filosofia y Letras; ArgentinaFil: D`angelo, José Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Científico Tecnológico Mendoza. Instituto Argentino de Nivologia, Glaciologia y Ciencias Ambientales; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentin

Propiedades fisico-químicas de sedimentos condicionan la asociación de contaminantes : un estudio multivariado de éteres bifenilos polibromados en áreas de irrigación del Río Mendoza

This work is a multidisciplinary environmental study that provides new insights into the relationships between sediment-organic matter characteristics and polybrominated diphenyl ethers (PBDEs) concentration. The aim of the present multivariate study was to correlate factors influencing PBDEs accumulation in sediment by using principal component analysis (PCA). Organic matter studies by Fourier Transform-Infrared spectroscopy and physicochemical analyses (Total Organic Carbon, pH, electrical conductivity) of sediment samples were considered for PCA. Samples were collected from an artificial irrigation network on the Mendoza River irrigation areas. PCA provided a comprehensive analysis of the studied variables, identifying two components that explained 63% of the data variance. Those factors were mainly associated to organic matter degradation degree, which represent a new insight into the relationships between organic matter in sediments and PBDEs fate. In this sense it was possible to determine that not only the content but also the type of organic matter (chemical structure) could be relevant when evaluating PBDEs accumulation and transport in the environment. Typification of organic matter may be a useful tool to predict more feasible areas where PBDE, may accumulate, as well as sediment transportation capability.Este trabajo es un estudio ambiental multidisciplinario que proporciona nuevos conocimientos sobre las relaciones entre las características de la materia orgánica presente en sedimentos y la concentración de éteres difenilos polibromados (PBDEs). Se buscó correlacionar características físico-químicas de muestras de sedimento usando análisis de componentes principales (PCA). Las muestras fueron caracterizadas por su contenido de materia orgánica total, pH y conductividad eléctrica. Adicionalmente, la materia orgánica de dichas muestras fue analizada mediante Espectroscopía de Infrarrojos con Transformada de Fourier. Las muestras fueron colectadas en diferentes canales de irrigación de la red alimentada por el Río Mendoza. El PCA proporcionó un análisis exhaustivo de las variables estudiadas y su vinculación, resultando dos componentes que explicarían el 63% de la varianza de los datos. Ambas componentes se asociaron al estado de degradación de la materia orgánica. En este sentido, fue posible determinar que tanto la cantidad de materia orgánica de los sedimentos como el tipo (estructura química) de materia orgánica estarían condicionando la acumulación y el transporte de PBDEs en el ambiente. A partir de los resultados es posible proponer a la tipificación de la materia orgánica de sedimento como herramienta útil y efectiva para predecir áreas donde es más factible que se acumule PBDE, así como la capacidad de transporte en los sedimentos.Fil: Lana, Nerina Belén. Instituto Argentino de Nivología, Glaciología y Ciencias AmbientalesFil: Koch, Eduardo.Fil: D' Angelo, José Alejandro. Instituto Argentino de Nivología, Glaciología y Ciencias AmbientalesFil: Ciocco, Nestor Fernando.Fil: Altamirano, Jorgelina Cecilia. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientale

Fossilization model for squamastrobus tigrensis foliage in a volcanic-Ash deposit: Implications for preservation and taphonomy (podocarpaceae, lower cretaceous, Argentina)

The present study is a holistic approach to the relationship between volcaniclastic host rock characteristics and the fossilization processes of short leafy coniferous branches of Squamastrobus tigrensis, preserved as fossilized-cuticles (Lower Cretaceous, Baqueró Group, Patagonia, Argentina). The question of diagenetic influences of Aptian volcaniclastic sedimentation on preservation chemistry and taphonomic processes is addressed. Whereas infrared spectroscopy provided chemical information on the leaves, vitrinite reflectance and complementary thermal indicators provided data on the thermal maturity of the dispersed organic matter in the host rock. Three sample types were analyzed: Fossilized-cuticle, macerated fossilized-cuticle (by infrared spectroscopy), and associated organic host rock matter (by light microscopy). Results clearly show chemical variability between, and within the fossilized-cuticle and cuticle, as well as a similarity to type I/II kerogen, i.e., high contents of both aliphatic groups and oxygencontaining compounds. Combined with the lower maturity of the host rock, the importance of the depositional environment during burial and taphonomic conditions that affected the fossilization of S. tigrensis are summarized in a general fossilization model.Fil: Lafuente Diaz, Maiten Amalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: D`angelo, José Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Cape Breton University; CanadáFil: 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: Zodrow, Erwin L.. Cape Breton University; Canad

Propiedades fisico-químicas de sedimentos condicionan la asociación de contaminantes: un estudio multivariado de éteres bifenilos polibromados en áreas de irrigación del Río Mendoza

This work is a multidisciplinary environmental study that provides new insights into the relationships between sediment-organic matter characteristics and polybrominated diphenyl ethers (PBDEs) concentration. The aim of the present multivariate study was to correlate factors influencing PBDEs accumulation in sediment by using principal component analysis (PCA). Organic matter studies by Fourier Transform-Infrared spectroscopy and physicochemical analyses (Total Organic Carbon, pH, electrical conductivity) of sediment samples were considered for PCA. Samples were collected from an artificial irrigation network on the Mendoza River irrigation areas. PCA provided a comprehensive analysis of the studied variables, identifying two components that explained 63% of the data variance. Those factors were mainly associated to organic matter degradation degree, which represent a new insight into the relationships between organic matter in sediments and PBDEs fate. In this sense it was possible to determine that not only the content but also the type of organic matter (chemical structure) could be relevant when evaluating PBDEs accumulation and transport in the environment. Typification of organic matter may be a useful tool to predict more feasible areas where PBDE, may accumulate, as well as sediment transportation capability.Este trabajo es un estudio ambiental multidisciplinario que proporciona nuevos conocimientos sobre las relaciones entre las características de la materia orgánica presente en sedimentos y la concentración de éteres difenilos polibromados (PBDEs). Se buscó correlacionar características físico-químicas de muestras de sedimento usando análisis de componentes principales (PCA). Las muestras fueron caracterizadas por su contenido de materia orgánica total, pH y conductividad eléctrica. Adicionalmente, la materia orgánica de dichas muestras fue analizada mediante Espectroscopía de Infrarrojos con Transformada de Fourier. Las muestras fueron colectadas en diferentes canales de irrigación de la red alimentada por el Río Mendoza. El PCA proporcionó un análisis exhaustivo de las variables estudiadas y su vinculación, resultando dos componentes que explicarían el 63% de la varianza de los datos. Ambas componentes se asociaron al estado de degradación de la materia orgánica. En este sentido, fue posible determinar que tanto la cantidad de materia orgánica de los sedimentos como el tipo (estructura química) de materia orgánica estarían condicionando la acumulación y el transporte de PBDEs en el ambiente. A partir de los resultados es posible proponer a la tipificación de la materia orgánica de sedimento como herramienta útil y efectiva para predecir áreas donde es más factible que se acumule PBDE, así como la capacidad de transporte en los sedimentos

Estimating the global conservation status of more than 15,000 Amazonian tree species

Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century