Impact of coal mining on water quality of three artificial lakes in Morozini River Basin (Treviso, Santa Catarina State, Brazil)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Thermodynamic properties of water sorption of jackfruit (Artocarpus heterophyllus Lam.) as a function of moisture content

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Study of the enthalpy-entropy mechanism from water sorption of orange seeds (C. sinensis cv. Brazilian) for the use of agro-industrial residues as a possible source of vegetable oil production

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Vertical distribution of zooplankton in the water column of Lago Amapá, Rio Branco, Acre, Brazil

O objetivo desta investigação foi observar a distribuição vertical da comunidade do zooplâncton no Lago Amapá (10º2'36S e 67º50'24W), localizado na planície de inundação do Rio Acre. Amostragens foram conduzidas em três diferentes profundidades da coluna da água, considerando aspectos sazonais do zooplâncton, parâmetros físicos, químicos e biológicos. Coletas foram realizadas semanalmente com Garrafa de Van Dorn. As espécies apresentaram maiores concentrações no meio da coluna da água. Foram encontradas 38 espécies, assim distribuídas: Rotifera (30), Cladocera (5) e Cyclopoida (3). A temperatura da coluna da água em geral apresentou-se alta, em torno de 30ºC, com pequena variação, resultando em baixa viscosidade. O índice de Jaccard, comparando-se as três estações de coletas, demonstrou que durante a fase de águas baixas, as estações 1 e 3 foram as mais similares (Cj = 0.7058), especialmente no meio da coluna da água. Lago Amapá apresentou características em conformidade com o Modelo do Distúrbio Intermediário, favorecendo a colonização de grupos oportunistas, tais como rotíferos.

Species richness of pteridophytes in a montane Atlantic rain forest plot of Southern Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Swarming of millipedes, a new case noticed in the District of Patrocinio-MG-Brazil

A population boom of the millipede Plusioporus setigerhas been recorded in coffee crops in the district of Patrocinio-MG, Brazil on the last five years. The millipedes spread over dwelling houses and to vegetable gardens, orchards and small plantations. It was suggested that population increase occurred as a consequence of the organic materials in high scale and also periodic irrigation in the coffee crop.

Terrane transfer during the Grenville orogeny: tracing the Amazonian ancestry of southern Appalachian basement through Pb and Nd isotopes

Whole rock Pb isotope data can be used to determine the provenance of different blocks within the Rodinia supercontinent, providing a test for paleogeographic reconstructions. Calculated isotopic values for the source region of the Grenville-deformed SW Amazon craton (Rondonia, Brazil), anchored by published U-Pb zircon ages, are compared to those from the Grenville belt of North America and Grenvillian basement inliers in the southern Appalachians. Both the SW Amazon craton and the allochthonous Blue Ridge/Mars Hill terrane are defined by a similar Pb isotopic signature, indicating derivation from an ancient source region with an elevated U/Pb ratio. In contrast, the Grenville Province of Laurentia (extending from Labrador to the Llano Uplift of Texas) is characterized by a source region with a distinctly lower, time-integrated U/Pb ratio. Published U-Pb zircon ages (ca. 1.8 Ga) and Nd model ages (1.4-2.2 Ga) for the Blue Ridge/Mars Hill terrane also suggest an ancient provenance very different from the rest of the adjacent Grenville belt, which is dominated by juvenile 1.3-1.5 Ga rocks. The presence of mature continental material in rocks older than 1.15 Ga in the Blue Ridge/ Mars Hill terrane is consistent with characteristics of basement rocks from the SW Amazon craton. High-grade metamorphism of the Blue Ridge/Mars Hill basement resulted in purging of U, consistent with observations of the rest of the North American Grenville province. In contrast, the Grenvillian metamorphic history of the Amazon appears to have been much more heterogeneous, with both U enrichment and U depletion recorded locally. We propose that the Blue Ridge/ Mars Hill portion of the Appalachian basement is of Amazonian provenance and was transferred to Laurentia during Grenvillian orogenesis after similar to1.15 Ga. The presence of these Amazonian rocks in southeastern Laurentia records the northward passage of the Amazon craton along the Laurentian margin, following the original collision with southernmost Laurentia at ca. 1.2 Ga. (C) 2004 Elsevier B.V. All rights reserved.

Mechanical properties, hydrophilicity and water activity of starch-gum film: effect of additives and deacetylated xanthan gum

The effect of deacetylated xanthan gum, additives (sucrose, soybean oil, sodium phosphate and propylene glycol) and pH modifications on mechanical properties, hydrophilicity and water activity of cassava starch-xanthan gum films has been studied. Sucrose addition resulted in the highest effect observed on cassava starch films elongation at break. The deacetylated xanthan gum had higher effect on elongation at break when comparing to the acetylated gum, although both gums presented an inferior effect in relation to the obtained with sucrose. However, when comparing to the control and PVC films, lower tensile strength resistance values were observed when adding sucrose. Increased water activity was observed for films added with sucrose, thus, increasing the material biodegradation. Sucrose and deacetylated xanthan gum addition resulted in a slight hydrophilicity increase. (C) 2004 Elsevier Ltd. All rights reserved.

Small mammals in the diet of barn owls (Tyto alba) in agroecosystems of southern Brazil

We studied the diet of the Barn Owl (Tyto alba) in an agricultural area of southern Brazil (29degrees36'S, 52degrees11'W), based on analysis of regurgitated remains. The results clearly showed that the diet of the Barn Owl reflects the human impact on its habitat. The cosmopolitan house mouse (Mus musculus) was the most preyed upon small mammal (81.9%) and the most important in terms of the Barn Owl ingested biomass (69%). This rodent, due to its small size, is also responsible for the relatively low me-an weight off small mammal prey in the owl diet (19.6 g). In southern Brazilian agroecosystems, the Barn Owl probably feeds mainly on mice due to their great abundance in crop fields and grain storage areas of the region.

Study on the initial stages of water corrosion of fluorozirconate glasses

The surface corrosion process associated with the hydrolysis of fluorozirconate glass, ZBLAN (53ZrF(4), 20BaF(2), 20NaF, 4LaF(2), 3AlF(3)) was investigated using X-ray photoelectron spectroscopy (XPS), grazing-incidence small angle X-ray scattering (GISAXS), X-ray reflectivity (XRR) and scanning electron microscopy (SEM). After a short exposure period (25 min) of the glass surface to deionized water the XPS data indicate an increase of the oxygen content accompanied by a decrease of fluorine concentration. The analysis of the chemical bonding structure identified the predominant surface reaction products as zirconium hydroxyfluoride and oxyfluoride species. The second most abundant glass component, bariumfluoride, remains almost unaffected by oxygen, while sodium fluoride is completely removed from the attacked surface region. The detected structural and compositional changes are related to the selective dissolution of the glass components leading to the formation of a new surface phase. This process is accompanied by a visible surface roughening caused by reprecipitated species, observed by SEM. The modification of the glass surface is responsible for an increase of the GISAXS intensity. The scattering was attributed to nanovoids formed at the surface region of the glass with an average size of 2.4 +/- 0.05 nm. (C) 2004 Elsevier B.V. All rights reserved.

Precipitation chemistry in semi-arid areas of Southern Africa: A case study of a rural and an industrial site

Experimental data on the precipitation chemistry in the semi-arid savanna of South Africa is presented in this paper. A total of 901 rainwater samples were collected with automatic wet-only samplers at a rural site, Louis Trichardt, and at an industrial site, Amersfoort, from July 1986 to June 1999. The chemical composition of precipitation was analysed for seven inorganic and two organic ions, using ion chromatography. The most abundant ion was SO(4)(2-) and a large proportion of the precipitation is acidic, with 98% of samples at Amersfoort and 94% at Louis Trichardt having a pH below 5.6 ( average pH of 4.4 and 4.9, respectively). This acidity results from a mixture of mineral and organic acids, with mineral acids being the primary contributors to the precipitation acidity in Amersfoort, while at Louis Trichardt, organic and mineral acids contribute equal amounts of acidity. It was found that the composition of rainwater is controlled by five sources: marine, terrigenous, nitrogenous, biomass burning and anthropogenic sources. The relative contributions of these sources at the two sites were calculated. Anthropogenic sources dominate at Amersfoort and biomass burning at Louis Trichardt. Most ions exhibit a seasonal pattern at Louis Trichardt, with the highest concentrations occurring during the austral spring as a result of agricultural activities and biomass combustion, while at Amersfoort it is less pronounced due to the dominance of relatively constant industrial emissions. The results are compared to observations from other African regions.

XPS study on water corrosion of fluorzirconate glasses and their protection by a layer of surface modified tin dioxide nanoparticles

The surface corrosion process associated with the hydrolysis of fluorozirconate glass, Z-BLAN (53ZrF(4), 20BaF(2), 20NaF, 4LaF(2), 3AlF(3)), and the corrosion protection efficiency of a nanocrystalline transparent SnO2 layer were investigated by X-ray photoelectron spectroscopy. The tin oxide film was deposited by the sol-gel dip-coating process in the presence of Tiron(R) as particle surface modifier agent. The chemical bonding structure and composition of the surface region of coated and non-coated ZBLAN were studied before water contact and after different immersion periods (5-30 min). In contrast to the effects occurring for non-coated glass, where the surface undergoes a rapid selective dissolution of the most soluble species inducing the formation of a new surface phase consisting of stable zirconium oxyfluoride, barium fluoride and lanthanum fluoride species, the results for the SnO2-coated glass showed that the hydrolytic attack induces a filling of the film nanopores by dissolved glass material and the formation of tin oxylluoride and zirconium oxyfluoride species. This process results in a modified film, which acts as a hermetic diffusion barrier protecting efficiently the glass surface. (C) 2006 Elsevier B.V. All rights reserved.

Water regulation of actinomycin-D binding to DNA: the interplay among drug affinity, DNA long-range conformation, and hydration

Actiaomycin-D (actD) binds to natural DNA at two different classes of binding sites, weak and strong. The affinity for these sites is highly dependent on DNA se(sequence and solution conditions, and the interaction appears to be purely entropic driven Although the entropic character of this reaction has been attributed to the release of water molecules upon drug to DNA complex formation, the mechanism by which hydration regulates actD binding and discrimination between different classes of binding sites on natural DNA is still unknown. In this work, we investigate the role of hydration on this reaction using the osmotic stress method. We skew that the decrease of solution water activity, due to the addition of sucrose, glycerol ethylene glycol, and betaine, favors drug binding to the strong binding sites on DNA by increasing both the apparent binding affinity Delta G, and the number of DNA base pairs apparently occupied by the bound drug n(bp/actD). These binding parameters vary linearly with the logarithm of the molar fraction of water in solution log(X-w), which indicates the contribution of water binding to the energetic of the reaction. It is demonstrated that the hydration change measured upon binding increases proportionally to the apparent size of the binding site n(bp/uctD). This indicates that n(bp/actD) measured from the Scatchard plod is a measure of the size of the DNA molecule changing conformation due to ligand binding. We also find that the contribution of DNA deformation, gauged by n(bp/act) to the total free energy of binding Delta G, is given by Delta G = Delta G(local) + n(bp/actD) x delta G(DNA), where Delta G(local), = -8020 +/- 51 cal/mol of actD bound and delta G(DNa) = -24.1 +/- 1.7cal/mol of base pair at 25 degrees C. We interpret Delta G(local), as the energetic contribution due to the direct interactions of actD with the actual tetranucleotide binding site, and it n(bp/actB) X delta G(DNA) as that due to change inconformation, induced by binding, of it n(bp/actD) DNA base pairs flanking the local site. This interpretation is supported by the agreement found between the value of delta G(DNA) and the torsional free energy change measured independently. We conclude suggesting an allosteric model for ligand binding to DNA, such that the increase in binding affinity is achieved by increasing the relaxation of the unfavorable free energy of binding storage at the local site through a larger number of DNA base pairs. The new aspect on this model is that the size of the complex is not fixed but determined by solutions conditions, such as water activity, which modulate the energetic barrier to change helix conformation. These results may suggest that long-range allosteric transitions of duplex DNA are involved in the inhibition of RNA synthesis by actD, and more generally, in the regulation of transcription. (C) 2000 John Wiley & Sons, Inc.

Comparing emergy accounting with well-known sustainability metrics: The case of Southern Cone Common Market, Mercosur

The quality and the power of human activities affect the external environment in different ways that can be measured and evaluated by means of several approaches and indicators. While the scientific community has been publishing several proposals for sustainable development indicators, there is still no consensus regarding the best approach to the use of these indicators and their reliability to measure sustainability. It is important, therefore, to question the effectiveness of sustainable development indicators in an effort to continue in the search for sustainability. This paper compares the results obtained with emergy accounting with five global Sustainability Metrics (SMs) proposed in the literature to verify if metrics are communicating coherent and similar information to guide decision makers towards sustainable development. Results obtained using emergy indices are discussed with the aid of emergy ternary diagrams. Metrics are confronted with emergy results, and the degree of variability among them is analyzed using a correlation matrix created for the Mercosur nations. The contrast of results clearly shows that metrics arrive at different interpretations about the sustainability of the nations studied, but also that some metrics may be grouped and used more prudently. Mercosur is presented as a case study to highlight and explain the discrepancies and similarities among Sustainability Metrics, and to expose the extent of emergy accounting. (C) 2010 Elsevier Ltd. All rights reserved.