Fisiologia, qualidade e produtividade da videira cv Syrah em diferentes estratégias de irrigação no semiárido

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Da fonte à bacia: interação continente-oceano no sistema sedimentar Rio São Francisco, Brasil

Pós-graduação em Geociências e Meio Ambiente - IGCE

Oscilações climáticas Plio-Pleistocênicas e sua influência na prospecção de ouro na área do garimpo do Manelão (PA)

No garimpo do Manelão, o ouro está associado a veios de quartzo encaixados na seqüência metavulcano-sedimentar São Manoel. No período Plio-Pleistoceno, sob um clima úmido, desenvolveu-se sobre a seqüência São Manoel uma cobertura laterítica autóctone e imatura. Essa cobertura residual contém partículas de ouro com elevada pureza, sugerindo processos de lixiviação da liga Au-Ag ou de remobilização e redeposição do Au em ambiente laterítico. Durante o Pleistoceno, o clima tornou-se árido a semi-árido, favorecendo a erosão parcial da cobertura laterítica, através dos processos coluviais associados a enxurradas periódicas. Esse depósito coluvial recobre o perfíl laterítico, destruindo um possível padrão de dispersão geoquímica do ouro supergênico e prejudicando a prospecção geoquímica de superfície. No final do Pleistoceno e início do Holoceno, o clima úmido retorna, juntamente com os processos de intemperismo, formando stone line e latossolos. As coberturas laterítica e coluvial serviram de área-fonte para os aluviões atuais a subatuais do igarapé São Manoel, onde o ouro ocorre livre nos estratos sedimentares mais basais, formando concentrações da ordem de 10 g/ton.

Estrutura populacional e análise de variabilidade genética em rebanhos ovinos brasileiros

Pós-graduação em Ciência e Tecnologia Animal - FEIS

Fisiologia, qualidade e produtividade da videira cv Syrah em diferentes estratégias de irrigação no semiárido

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Da fonte à bacia: interação continente-oceano no sistema sedimentar Rio São Francisco, Brasil

Pós-graduação em Geociências e Meio Ambiente - IGCE

Comparative analysis of rating curve and ADP estimates of instantaneous water discharge through estuaries in two contrasting Brazilian rivers

This work quantifies, using ADP and rating curve techniques, the instantaneous outflows at estuarine interfaces: higher to middle estuary and middle to lower estuary, in two medium-sized watersheds (72 000 and 66 000 km(2) of area, respectively), the Jaguaribe and Contas Rivers located in the northeastern (semi-arid) and eastern (tropical humid) Brazilian coasts, respectively. Results from ADP showed that the net water balances show the Contas River as a net water exporter, whereas the Jaguaribe River Estuary is a net water importer. At the Jaguaribe Estuary, water retention during flood tide contributes to 58% of the total volume transferred during the ebb tide from the middle to lower estuary. However, 42% of the total water volume (452 m(3) s(-1)) that entered during flood tide is retained in the middle estuary. In the Contas River, 90% of the total water is retained during the flood tide contributing to the volume transported in the ebb tide from the middle to the lower estuary. Outflows obtained with the rating curve method for the Contas and Jaguaribe Rivers were uniform through time due to river flow normalization by dams in both basins. Estimated outflows with this method are about 65% (Contas) and 95% (Jaguaribe) lower compared to outflows obtained with ADP. This suggests that the outflows obtained with the rating curve method underestimate the net water balance in both systems, particularly in the Jaguaribe River under a semi-arid climate. This underestimation is somewhat decreased due to wetter conditions in the Contas River basin. Copyright. (C) 2011 John Wiley & Sons, Ltd.

Flexible and conservative features of social systems in tufted capuchin monkeys: comparing the socioecology of Sapajus libidinosus and Sapajus nigritus

Socioecological models assume that primates adapt their social behavior to ecological conditions, and predict that food availability and distribution, predation risk and risk of infanticide by males affect patterns of social organization, social structure and mating system of primates. However, adaptability and variation of social behavior may be constrained by conservative adaptations and by phylogenetic inertia. The comparative study of closely related species can help to identify the relative contribution of ecological and of genetic determinants to primate social systems. We compared ecological features and social behavior of two species of the genus Sapajus, S. nigritus in Carlos Botelho State Park, an area of Atlantic Forest in Sao Paulo state, and S. libidinosus in Fazenda Boa Vista, a semi-arid habitat in Piaui state, Brazil. S. libidinosus perceived higher predation risk and fed on clumped, high quality, and usurpable resources (fruits) all year round, whereas S. nigritus perceived lower predation risk and relied on evenly distributed, low-quality food sources (leaves) during periods of fruit shortage. As predicted by socioecology models, S. libidinosus females were philopatric and established linear and stable dominance hierarchies, coalitions, and grooming relationships. S. nigritus females competed less often, and could transfer between groups, which might explain the lack of coalitions and grooming bonds among them. Both populations presented similar group size and composition and the same polygynous mating system. The species differed from each other in accordance with differences in the characteristics of their main food sources, as predicted by socioecological models, suggesting that phylogenetic inertia does not constrain social relationships established among female Sapajus. The similarity in mating systems indicates that this element of the social system is not affected by ecological variables and thus, is a more conservative behavioral feature of the genus Sapajus. Am. J. Primatol. 74:315331, 2012. (c) 2011 Wiley Periodicals, Inc.

The First Occurrence in the Fossil Record of an Aquatic Avian Twig-Nest with Phoenicopteriformes Eggs: Evolutionary Implications

Background: We describe the first occurrence in the fossil record of an aquatic avian twig-nest with five eggs in situ (Early Miocene Tudela Formation, Ebro Basin, Spain). Extensive outcrops of this formation reveal autochthonous avian osteological and oological fossils that represent a single taxon identified as a basal phoenicopterid. Although the eggshell structure is definitively phoenicopterid, the characteristics of both the nest and the eggs are similar to those of modern grebes. These observations allow us to address the origin of the disparities between the sister taxa Podicipedidae and Phoenicopteridae crown clades, and traces the evolution of the nesting and reproductive environments for phoenicopteriforms. Methodology/Principal Findings: Multi-disciplinary analyses performed on fossilized vegetation and eggshells from the eggs in the nest and its embedding sediments indicate that this new phoenicopterid thrived under a semi-arid climate in an oligohaline (seasonally mesohaline) shallow endorheic lacustine environment. High-end microcharacterizations including SEM, TEM, and EBSD techniques were pivotal to identifying these phoenicopterid eggshells. Anatomical comparisons of the fossil bones with those of Phoenicopteriformes and Podicipediformes crown clades and extinct palaelodids confirm that this avian fossil assemblage belongs to a new and basal phoenicopterid. Conclusions/Significance: Although the Podicipediformes-Phoenicopteriformes sister group relationship is now well supported, flamingos and grebes exhibit feeding, reproductive, and nesting strategies that diverge significantly. Our multi-disciplinary study is the first to reveal that the phoenicopteriform reproductive behaviour, nesting ecology and nest characteristics derived from grebe-like type strategies to reach the extremely specialized conditions observed in modern flamingo crown groups. Furthermore, our study enables us to map ecological and reproductive characters on the Phoenicopteriformes evolutionary lineage. Our results demonstrate that the nesting paleoenvironments of flamingos were closely linked to the unique ecology of this locality, which is a direct result of special climatic (high evaporitic regime) and geological (fault system) conditions.

Cellulolytic bacteria from soils in harsh environments

It is believed that the exposure of organisms to harsh climate conditions may select for differential enzymatic activities, making the surviving organisms a very promising source for bioprospecting. Soil bacteria play an important role in degradation of organic matter, which is mostly due to their ability to decompose cellulose-based materials. This work focuses on the isolation and identification of cellulolytic bacteria from soil found in two environments with stressful climate conditions (Antarctica and the Brazilian semi-arid caatinga). Cellulolytic bacteria were selected using enrichments at high and low temperatures (4 or 60A degrees C) in liquid media (trypic soy broth-TSB and minimum salt medium-MM) supplemented with cellulose (1%). Many of the isolates (119 out of 254-46.9%) displayed the ability to degrade carboxymethyl-cellulose, indicating the presence of endoglucolytic activity, while only a minority of these isolates (23 out of 254-9.1%) showed exoglucolytic activity (degradation of avicel). The obtained isolates revealed a preferential endoglucolytic activity according to the temperature of enrichments. Also, the identification of some isolates by partial sequencing of the 16S rRNA gene indicated that the Bacteroidetes (e.g., Pedobacter, Chryseobacterium and Flavobacterium) were the main phylum of cellulolytic bacteria isolated from soil in Antarctica; the Firmicutes (e.g., Bacillus) were more commonly isolated from samples from the caatinga; and Actinobacteria were found in both types of soil (e.g., Microbacterium and Arthrobacter). In conclusion, this work reports the isolation of bacteria able to degrade cellulose-based material from soil at very low or very high temperatures, a finding that should be further explored in the search for cellulolytic enzymes to be used in the bioenergy industry.

Taxonomical study on a sample of pulmonates from Santa Maria da Vitória, Bahia, Brazil, with description of a new genus and four new species (Mollusca: Orthalicidae and Megalobulimidae)

A sample of Pulmonata collected in Santa Maria da Vitória, interior of Bahia, Brazil, in Caatinga semi-arid environment, is studied taxonomically. From the five species, four are revealed as new, including a new genus. The new taxa are the Bulimulidae (1) Kora corallina gen. et sp. n. characterized by the elongated shell with aperture somewhat dislocated from the shell axis, and an oblique tooth in middle level of inner lip; (2) Spixia coltrorum, mainly characterized by an uneven spire, delicate sculpture and peristome with 4 equidistant teeth; (3) Anostoma tessa, mainly characterized by a broad spire and well-developed anal canal; and the Megalobulimidae (4) Megalobulimus amandus, mainly characterized by pointed protoconch sculptured by dense quantity of axial cords. Rhinus suturalis is the only previously known species, but its geographic distribution is expanded southwards to Bahia state. A discussion with respect to necessity for improving the study on the malacofauna from the interior region of the Brazilian Northeast and the importance for preservation of the Caatinga biome is also provided.

Estoques de carbono e nitrogênio no solo cultivado com mamona na Caatinga

Grande parte da produção brasileira de mamona encontra-se no Nordeste, como opção de cultura para a região semiárida no bioma Caatinga. O objetivo deste estudo foi avaliar as alterações nos estoques de C e N devido à mudança de uso do solo de vegetação natural para o cultivo de mamona no bioma Caatinga. Este trabalho foi realizado na Fazenda Floresta, no município de Irecê, no centro-norte baiano. O clima da região é do tipo BSwh (Köppen) - clima semiárido de altitude. O solo foi classificado em Latossolo Vermelho de textura argilosa. As situações avaliadas foram: três áreas cultivadas com mamona com diferentes tempos de implantação: (i) com 10 anos, (ii) com 20 anos e (iii) com 50 anos; e uma área de referência (vegetação nativa de Caatinga) contígua às situações avaliadas. Os estoques de C e N foram determinados em amostras de solo coletadas em cinco minitrincheiras, nas camadas de 0-5, 5-10, 10-20 e 20-30 cm. Os resultados mostraram que o constante aporte de resíduos vegetais na Caatinga promoveu a manutenção dos estoques de C (90 Mg ha-1) e N (10 Mg ha-1) para a camada de 0-30 cm. A mudança de uso da terra para o cultivo da mamona ocasiona redução em aproximadamente 50 % nos estoques de C e N do solo em relação à vegetação nativa nos primeiros 10 anos de implantação da cultura. A meia-vida da matéria orgânica do solo (MOS) calculada para essa situação na região do semiárido foi de 4,7 anos. O fator de emissão de C do solo, devido à mudança de uso da terra após 20 anos, conforme proposto pelo método do IPCC (2006), foi de 2,47 Mg C ano-1. Por meio do conjunto dos resultados, observa-se a fragilidade do solo do bioma Caatinga no que se refere à perda de MOS devido à mudança de uso da terra.

La explotación del acuífero de la Aldea (Gran Canaria) desde el punto de vista de la directiva marco del agua

[ES] El valle de La Aldea, al oeste de Gran Canaria, se dedica a la agricultura intensiva en un clima semi-árido. El agua de riego proviene de aguas superficiales y subterráneas. El acuífero está aislado del resto de la isla por el borde impermeable de la Caldera de Tejeda. El aluvial principal de La Aldea se comporta como un depósito de almacenamiento de agua que se llena y vacía, con un tiempo medio de renovación de aproximadamente 2 años. Las aguas subterráneas muestran una alta salinidad de origen natural, debido a la evapoconcentración de la deposición atmosférica y la interacción agua-roca, y antropogénica debida a los retornos de riego que producen contenidos en nitratos que pueden alcanzar los 700 mg/L. Se ha establecido un modelo conceptual de funcionamiento del acuífero y se han cuantificado los términos del balance de agua. El uso actual del acuífero está en conflicto con los requerimientos de la Directiva Marco del Agua (DMA). Sin embargo, dado que su uso es clave para el desarrollo económico del valle de La Aldea en particular, cabe plantear las excepciones legales específicas previstas en la DMA.

The ecological and socio-economic role of Prosopis juliflora in Eritrea

In Eritrea findet eine rasche Verbreitung von Prosopis (juliflora) statt, die sich negativ auf die Naturresourcen als auch die sozio-ökonomische Lage der ländlichen Bevölkerung auswirkt. Die Landbevölkerung Eritrea's ist davon überzeugt, dass die Pflanze vor allem die Ernährungssicherung beeinträchtigt und will deshalb, dass sie ausgerottet wird. Die vorliegende Dissertation beschreibt die Auswirkung von Posopis auf lokale Öko- und Wirtschaftssysteme und zieht Vergleiche mit der diesbezüglichen Situation in anderen Ländern. Im Weiteren stellt sie einen Prosopis Management-Plan vor, dessen Ziel es ist, die zunehmende Verbreitung zu verhindern. Auch liefert sie eine Gegenüberstellung der Ansichten von wissenschaftlichen Experten einerseits und Bauern und Nomaden andrerseits. Sie zeigt auf, dass die weit verbreitete Annahme der Experten das Problem Prosopis durch ökonomische Nutzung ("eradication by utilisation") in Schach halten zu können, fraglich ist.

Microscopic and spectroscopic analysis of biogenic aerosols

Aerosol particles are important actors in the Earth’s atmosphere and climate system. They scatter and absorb sunlight, serve as nuclei for water droplets and ice crystals in clouds and precipitation, and are a subject of concern for public health. Atmospheric aerosols originate from both natural and anthropogenic sources, and emissions resulting from human activities have the potential to influence the hydrological cycle and climate. An assessment of the extent and impacts of this human force requires a sound understanding of the natural aerosol background. This dissertation addresses the composition, properties, and atmospheric cycling of biogenic aerosol particles, which represent a major fraction of the natural aerosol burden. The main focal points are: (i) Studies of the autofluo-rescence of primary biological aerosol particles (PBAP) and its application in ambient measure-ments, and (ii) X-ray microscopic and spectroscopic investigations of biogenic secondary organic aerosols (SOA) from the Amazonian rainforest.rnAutofluorescence of biological material has received increasing attention in atmospheric science because it allows real-time monitoring of PBAP in ambient air, however it is associated with high uncertainty. This work aims at reducing the uncertainty through a comprehensive characterization of the autofluorescence properties of relevant biological materials. Fluorescence spectroscopy and microscopy were applied to analyze the fluorescence signatures of pure biological fluorophores, potential non-biological interferences, and various types of reference PBAP. Characteristic features and fingerprint patterns were found and provide support for the operation, interpretation, and further development of PBAP autofluorescence measurements. Online fluorescence detection and offline fluorescence microscopy were jointly applied in a comprehensive bioaerosol field measurement campaign that provided unprecedented insights into PBAP-linked biosphere-atmosphere interactions in a North-American semi-arid forest environment. Rain showers were found to trigger massive bursts of PBAP, including high concentrations of biological ice nucleators that may promote further precipitation and can be regarded as part of a bioprecipitation feedback cycle in the climate system. rnIn the pristine tropical rainforest air of the Amazon, most cloud and fog droplets form on bio-genic SOA particles, but the composition, morphology, mixing state and origin of these particles is hardly known. X-ray microscopy and spectroscopy (STXM-NEXAFS) revealed distinctly different types of secondary organic matter (carboxyl- vs. hydroxy-rich) with internal structures that indicate a strong influence of phase segregation, cloud and fog processing on SOA formation, and aging. In addition, nanometer-sized potassium-rich particles emitted by microorganisms and vegetation were found to act as seeds for the condensation of SOA. Thus, the influence of forest biota on the atmospheric abundance of cloud condensation nuclei appears to be more direct than previously assumed. Overall, the results of this dissertation suggest that biogenic aerosols, clouds and precipitation are indeed tightly coupled through a bioprecipitation cycle, and that advanced microscopic and spectroscopic techniques can provide detailed insights into these mechanisms.rn