New U-Pb zircon age constraints for the emplacement of the Reguengos de Monsaraz Massif (Ossa Morena Zone)

The Reguengos de Monsaraz massif is located in the Portuguese sector of the Ossa Morena Zone (ZOM), one of the major geotectonic units of the Iberian Variscan Belt. It intruded Lower Paleozoic metasediments, strongly affected by deformation and metamorphism during the Varis-can orogeny. Pluton emplacement was responsible for the development of a contact metamor-phism aureole in the surrounding country rocks. Based on regional constraints, the intrusion was included in the group of the late-post-tectonic granitoids. The pluton shows an inversely zoned pattern and consists of tonalitic to granodioritic rocks with abundant mafic microgranular enclaves, occupying most of the presently exposed intrusion area and minor bodies of gabbro-diorites in the east and centre. Field, petrographical and geo-chemical data reveal that mixing / mingling between mantle- and crustally-derived magmas and fractional crystallization played a major role in the genesis and evolution of these granitoids 1. Early attempts to date the Reguengos de Monsaraz intrusion, using Rb-Sr isotopic data for a feldspar-amphibole pair from one granodiorite sample, yielded an age of 297.5 ± 2.9 Ma. This age was interpreted as a cooling age and provided a minimum estimate for the timing of mag-matic crystallization. In order to better constrain the age and emplacement sequence of the mas-sif, five samples representing the different magmatic units (gabbro diorites, tonalites and mafic microgranular enclaves) were selected for determination of U-Pb zircon ages by isotope dilution techniques. The zircon populations from two samples of the gabbro diorites (one from the central sector and the other from the easternmost body) yielded overlapping 206Pb/238U average ages of 337.4 1.1 Ma and 338.6 ± 0.7 Ma, respectively. Similar ages were obtained in two samples from the main tonalite-granodiorite facies (337.3 ± 2.3 Ma; 337.8 ± 0.7 Ma). Finally, the zircons from the microgranular enclave yielded a 206Pb/238U average age of 336.5 ± 0.5 Ma. A slightly younger age was obtained in two fractions of titanite from the enclave (333.6 ± 2.5 Ma), suggesting either resetting of their original magmatic ages or late stage crystallization. The new U-Pb age data support a coeval emplacement for all the members of this suite, at ap-proximately 337-338 Ma. Such a close space-time association between mafic and felsic grani-toids is consistent with the proposed mixing model. According to recent studies, this sector of the OMZ was affected by three Variscan deforma-tion events 2. The earlier deformation phases (D1 and D2) occurred in Late Devonian ( 380-360 Ma) and Early Carboniferous times ( 360-345 Ma), whilst the latter (D3) has a Pennsylva-nian age (305-295 Ma). Based on the available geochronological information, the emplacement of the Reguengos de Monsaraz magmas took place at a time of tectonic quiescence between D2 and D3. The relatively young Rb-Sr age recorded in the feldspar-amphibole pair may therefore reflect the effects of the last tectonothermal event, also documented by the replacement of horn-blende crystals by actinolite

Geochronology and Isotope Geochemistry of Felsic Marginal Facies of the Reguengos de Monsaraz Pluton (OMZ)

No sector sueste do maciço de Reguengos de Monsaraz (Zona de Ossa-Morena), ocorrem rochas félsicas quer em continuidade espacial com as litologias principais do plutonito quer em pequenos corpos aparentemente separados. Neste trabalho, estudou-se o granito marginal da zona de Arraieiras, bem como o tonalito da zona do ribeiro dos Gagos. Datações U-Pb (em zircão e monazite) revelam que estas litologias são, no essencial, contemporâneas entre si, bem como relativamente às fácies mais comuns do maciço de Reguengos, e que os processos de instalação magmática deverão ter decorrido há 337-338 Ma. Do ponto de vista geoquímico, o granito de Arraieiras parece ter uma relação genética forte com o resto do plutonito, através de processos de mistura de líquidos (de origens mantélica e de anatexia de metassedimentos) e diferenciação magmática, a que se terão seguido fenómenos locais de assimilação do encaixante no nível de instalação final. O paradoxo de haver rochas mais máficas do que o granito com assinaturas isotópicas mais “crustais” poderá ser explicado pela intervenção final destes processos de assimilação. Quanto ao tonalito de Gagos, as suas características geoquímicas, e em particular as razões isotópicas de Sr e Nd, requerem uma origem distinta, com contribuição de fonte infracrustal.Felsic rocks occur in the SE sector of the Reguengos de Monsaraz massif either as a border zone of the pluton or as small satellite bodies. In this work, the Arraieiras granite (from the border zone) and the Gagos tonalite (from a satellite body) were studied for geochronology and geochemistry. The obtained zircon and monazite U-Pb ages show that the two felsic lithologies and the main units of the Reguengos pluton are essentially contemporaneous to each other and that magma emplacement took place at 337-338 Ma. Geochemical features of the Arraieiras granite suggest that it has a strong genetic link with the other lithologies of the pluton, through magma mixing (from mantle and metasedimentary sources) and differentiation processes; in a late evolutionary stage, at the final emplacement level, assimilation of country rock material also took place. The paradox of some more mafic rocks displaying isotope signatures more “crustal” than those revealed by the Arraieiras granite is probably a consequence of late assimilation events. In contrast, the Gagos tonalite, according to the Sr and Nd isotope fingerprints, seems to be related to a different sequence of processes and, in particular, it requires the contribution of an infracrustal source

EPIC-PHASE: a model to explore irrigation strategies

bstract The erosion productivity impact calculator phase (EPIC-PHASE) model has been used to simulate, using 1972 to 1994 climatic date, two irrigation strategies with a non-limited water supply: (1) a standard strategy based on simple decision rules advisable for moderately deep soils of the Lauragais region (France) and in the Alentejo region (Portugal); and (2) a model strategy based on the daily development of soil water depletion and daily water stress intensity predicted by the model. At Lauragais, the results show that for the same level of yield it would have been possible with the model to save 73 mm on average, equivalent of two irrigations per year, compared to the standard strategy. These savings are due to an increased soil water contribution during the cycle and to an earlier end of the irrigation supply. At Alentejo, the results show that for the same level of yield as obtained with the standard strategy, it would have been possible with EPIC-PHASE model to save 100 mm of water on average, equivalent of two irrigations per year due to an increased use of soil water during the cycle. Although the results are from simulations it is proved that the standard strategy is inadequate. Regarding the environmental impact, the model management allows for an increase in the level of water depletion at harvest, delaying the risk of percolation and nitrogen losses during the refill period. The EPIC-PHASE model proved to be a tool capable of defining an irrigation schedule better adapted to the Mediterranean region

Sr isotopic signatures of Portuguese bottled mineral waters, their relationships with the geological setting and potential use for product authentication

The Sr isotopic ratios of nine bottled natural mineral waters from Portugal were measured in the Laboratory of Isotope Geology of the University of Aveiro (LGIUA). The results obtained show that the Sr isotopic variability of these waters is strongly correlated with the age and mineralogical composition of the aquifer source rocks. The lowest 87Sr/86Sr ratios are found in water samples from the Monchique aquifer (87Sr/86Sr = 0,70447), located in Late Cretaceous alkaline magmatic rocks of mantle origin. The Vimeiro waters are hosted in carbonate and evaporite formations of Jurassic age and have 87Sr/86Sr values of 0,70808, whereas the waters sourced in Cenozoic siliciclastic sediments tend to exhibit higher 87Sr/86Sr ratios, close to the rainwater value (São Silvestre; 87Sr/86Sr = 0,71078). Finally, the waters coming from granitic and/or metamorphic terrains of the Iberian Variscan basement (Vitalis, Luso, Carvalhelhos, Fastio, Serra da Estrela) display the most radiogenic Sr isotopic signatures (87Sr/86Sr > 0,7136). In the modern commercial context, the differences encountered provide a powerful tool for fingerprinting the mineral water origin and may be used for purposes of mineral water authentication. The use of 87Sr/86Sr ratios may also be extended to studies on the provenance of some foods and beverages, taking into account the influence of the geological / pedological factor on the Sr isotopic composition recorded by the plants

Utilização agrícola e compostagem de lamas de origem têxtil

Utilização agrícola e compostagem de lamas de origem têxtil

Valorização agrícola de lamas de origem têxtil

Valorização agrícola de lamas de origem têxtil

Conjugated Linoleic Acid Supplementation: Lipid Content And Hepatic Histology In Healthy Wistar Rats [suplementação Com ácido Linoleico Conjugado: Conteúdo De Lípides E Histologia Hepática De Ratos Wistar Saudáveis]

This work aimed to evaluate the effects of the consumption of two commercial conjugated linoleic acid (CLA) mixtures on lipid content and liver histology of healthy rats. The investigation was carried out using thirty rats divided into three groups: C (control), AE (AdvantEdge®CLA), and CO (CLA One®). The concentration of CLA was 2% of feed consumption, and the animals were supplemented daily for 42 days. The total lipid content of the liver was determined, and the histology of the organ was examined by Transmission Electronic Microscopy. The results of total liver lipid contents did not exhibit significant differences between the groups. With regard to hepatic histology, it was observed that although fat globules were visibly present in higher numbers and bigger size in the CLA groups, the organ histology was considered normal since both cytoplasm and organelles showed integrity. It was concluded that even though liver microscopic images indicated the presence of fat globules in the liver, from a statistical point of view, the supplementation for 42 days did not bring about lipid accumulation, nor did it alter hepatic histology.311141146Adams, L.A., Angulo, P., Lindor, K.D., Nonalcoholic fatty liver disease (2005) Canadian Medical Association Journal, 172 (7), pp. 899-905Akbiyik, F., Ligand-induced expression of peroxissome proliferators activated receptor α and activation of fatty oxidation enzymes in fatty liver (2004) European Journal of Clinical Investigation, 34 (6), pp. 429-435Akyüz, F., What is the best indicator for evaluating treatment response in nonalcoholic fatty liver disease: Histology or aminotransferase levels? (2005) Journal of Gastroenterology and Hepatology, 20 (1), pp. 167-168Basu, S., Smedman, A., Vesby, B., Conjugated linoleic acid induces lipid peroxidation in humans (2000) FEBS Letters, 468 (1), pp. 33-36Belury, M.A., Conjugated linoleic acid is na activator and ligand for peroxissome proliferator-activated receptor-gama (PPARγ) (2002) Nutrition Research, 22 (7), pp. 817-824Belury, M.A., Kempa-Steczko, A., Conjugated linoleic acid modulates hepatic lipid composition in mice (1997) Lipids, 32 (2), pp. 199-204Bligh, E.G., Dyer, W.J., A rapid method of total lipid extration and purification (1959) Canadian Journal of Biochemistry and Physiology, 37 (8), pp. 911-917Brown, J.M., McIntosh, M.K., Conjugated linoleic acid in humans: Regulation of adiposity and insulin sensitivity (2003) Journal of Nutrition, 133 (10), pp. 3041-3046Brunt, E.M., Nonalcoholic steatohepatitis: Definition and pathology (2001) Seminars in Liver Disease, 21 (1), pp. 3-16Cherian, G., Dietary CLA alters yolk and tissue FA composition and hepatic histopathology of laying hens (2002) Lipids, 37 (8), pp. 751-757Cherian, G., Goeger, M.P., Hepatic lipid characteristics and histopathology of laying hens fed CLA or n-3 fatty acids (2004) Lipids, 39 (1), pp. 31-36Chituri, S., Farel, G.C., Etiopathogenesis of nonalcoholic steatohepatitis (2001) Seminars in Liver Disease, 21 (1), pp. 27-41Choi, J.S., Song, J., Conjugated linoleic acid, obesity, and insulin resistance: Waiting for the day of liberation from chronic disease (2005) Nutrition, 21 (11), pp. 1170-1172Clement, L., Dietary trans-10, cis-12 conjugated linoleic acid induces hyperinsulinemia and fatty liver in the mouse (2002) Journal Lipid Research, 43 (9), pp. 1400-1409Elitsur, Y., Treatment for NASH: The value of histology (2005) Journal Gastroenterology: A Journal of Clinical Gastroenterology, 100 (1), pp. 250-251Goena, M., Effect of the raw legume Vicia ervilha on muscle and liver protein metabolism in growing rats (1989) Revista Española de Fisiologia, 45 (SUPPL.), pp. 55-60Granlund, L., Trans10, cis12-conjugated linoleic acid prevents triacylglycerol accumulation in adipocytes by acting as a PPARγ modulator (2003) Journal of Lipid Research, 44 (8), pp. 1441-1452Haddad, A., (1998) Técnicas básicas de microscopia eletrônica aplicadas às ciências biológicas, , Rio de Janeiro: Sociedade Brasileira de MicroscopiaHoek, B.V., Non-alcoholic fatty liver disease: A brief review (2004) Scandinavian Journal of Gastroenterology, 39 (SUPPL.), pp. 56-59Kang, K., Trans-10, cis-12 CLA inhibits differentiation of 3T3-L1 adipocytes and decreases PPARγ expression (2003) Biochemical and Biophysical Research Communications, 303 (3), pp. 795-799Lavine, J.E., Vitamin E treatment of nonalcoholic steatohepatitis in children: A pilot study (2000) Journal of Pediatrics, 136 (6), pp. 734-738Ludwig, J., Nonalcoholic steatohepatitis. Mayo Clinic experience with a hitherto unnamed disease (1980) Mayo Clinic Procedings, 55 (7), pp. 434-438McArulla, M.T., Effects of conjugated linoleic acid on liver composition and fatty acid oxidation are isomer-dependent in hamster (2005) Nutrition, 21 (4), pp. 512-519Moya-Camarena, S.Y., Conjugated linoleic acid is a potent naturally occurring ligand and activator of PPARα (1999) Journal Lipid Research, 40 (8), pp. 1426-1433Oustrowska, E., Milk conjugated linoleic and trans-vaccenic acids are highest in Spring in grazing cows (2004) Asian Pacific Journal of Clinical Nutrition, 13 (SUPPL.), pp. S53Pariza, M.W., Effects of temperature and time on mutagen formation in pan-fried hamburger (1979) Cancer Letter, 7 (2-3), p. 63Pariza, M.W., Hargraves, W.A., A beef-derived mutagenesis modulator inhibits initiation of mouse epidermal tumors by 7,12-dimethylbenz[a]anthracene (1985) Carcinogenesis, 6 (4), p. 591Parodi, P.W., Conjugated octadecadienoic acids of milk fat (1977) Journal of Dairy Science, 60 (10), pp. 1550-1553Reeves, P.G., Nielsen, F.H., Fahey Jr., G.C., AIN-93 Purified diets for laboratory rodents: Final report of the American Institute of Nutrition Ad Hoc Writing Committee on the Reformulation of the AIN-76A rodent diet (1993) Journal of Nutrition, 123 (11), pp. 1939-1951Risérus, U., Effects of cis-9, trans-11 conjugated linoleic acid supplementation on insulin sensitivity, lipid peroxidation, and proinflamatory markers in obese men (2004) American Journal of Clinical Nutrition, 80 (2), pp. 279-283Salas-Salvadó, J., Marquez-Sandoval, F., Bulló, M., Conjugated linoleic acid intake in humans: A systematic review focusing on its effects on body composition, glucose, and lipid metabolism (2006) Critical Reviews in Food Science and Nutritio, 46 (6), pp. 479-488Santos-Zago, L.F., Botelho, A.P., Oliveira, A.C., Supplementation with commercial mixtures of conjugated linoleic acid in association with vitamin E and the process of lipid autoxidation in rats (2007) Lipids, 42 (9), pp. 845-854Sato, S., Ultrastructural and morphometric studies of normal rat hepatocytes (2004) Journal of Submicroscopic Cytology and Pathology, 36 (2), pp. 131-140Sehat, N., Identification of conjugated linoleic acid isomers in cheese by gas chromatography, silver ion high performance liquid chromatography and mass spectral reconstructed ion profiles. Comparison of chromatographic elution sequences (1998) Lipids, 33 (10), pp. 963-971(2003) Institute Project for Windows: User's guide: Statistics, , STATISTICAL ANALYSIS SYSTEM-SAS, Version 8.0. Cary: USA instVidela, L.A., Oxidative stress-related parameters in the liver of non-alcoholic fatty liver disease patients (2004) Clinical Science, 106 (3), pp. 261-268Yamasaki, M., Effect of Dietary Conjugated Linoleic Acid on Lipid Peroxidation and Histological Change in Rat Liver Tissues (2000) Journal of Agriculture and Food Chemistry, 48 (12), pp. 6367-637

Energy Conditions in f(G)f(G) Modified Gravity with Non-minimal Coupling to Matter

In this paper we study a model of modified gravity with non-minimal coupling between a general function of the Gauss-Bonnet invariant, $f(G)$, and matter Lagrangian from the point of view of the energy conditions. Such model has been introduced in Ref. [21] for description of early inflation and late-time cosmic acceleration. We present the suitable energy conditions for the above mentioned model and then, we use the estimated values of the Hubble, deceleration and jerk parameters to apply the obtained energy conditions to the specific class of modified Gauss-Bonnet models.Comment: 12 pages, no figur, Accepted for publication in Astrophysics and Space Scienc

In vitro cultivation of Brosimum gaudichaudii Tréc. (Moraceae)

O objetivo desta pesquisa foi avaliar o potencial organogenético de entrenós, discos foliares, e raízes de Brosimum gaudichaudii utilizando 12 diferentes combinações dos fitorreguladores 6-benzilaminopurina e ácido naftaleno acético, em meio MS (diluído à metade), sólido (6,5 g de ágar), e com 20 g.L-1 de sacarose. Independentemente das combinações hormonais testadas verificou-se a formação de calos friáveis (2 a 20 mm de diâmetro) em 90% dos entrenós usados como explantes. No entanto, os tratamentos testados não foram capazes induzir calos ou gemas em raízes e em discos foliares. O estudo anatômico revelou a formação de meristemóides nas regiões mais externa e mais interna dos calos. Os resultados obtidos poderão servir de base para novos testes de indução de calos na espécie.The objective of this research was to evaluate the organogenic potential of internodes, leaf discs and roots of Brosimum gaudichaudii using 12 different combinations of the plant growth regulators 6-benzylaminopurine and naphthalene acetic acid in MS medium (half strength), solid medium (6.5 g agar) and sucrose medium (20 g.L-1). Regardless the hormonal combination tested, we observed the formation of friable calluses (2 - 20 mm wide) in 90% of the internode explants. However, the treatments were not able to induce callus or buds on roots and leaf discs. The anatomical analysis revealed meristemoid formation in the outer and inner regions of the calluses. The results may serve as the basis for further testing of callus induction in this species