951 resultados para Central South Pacific


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A presente tese tem como objetivo principal a identificação dos aspectos institucionais, políticos, legais, e econômicos presentes no processo de colonização privada praticados por empresas e famílias nos municípios de São José do Rio Claro e Canarana, ambos no Estado de Mato Grosso. A importância em descortinar tais aspectos se dá em função da necessidade de compreender a colonização privada voltada para pequenos agricultores do Centro-Sul do país, alocados na Amazônia mato-grossense. Os aprofundamentos dessas análises permitirão subsidiar futuros processos de colonização, assim como, mitigar prováveis impactos negativos que se repercutem ainda hoje nesses municípios. A pesquisa foi operacionalizada em estudo de campo em ambos os municípios. A pesquisa bibliográfica e documental procurou levantar os aspectos da história econômica, da ocupação territorial, da presença das organizações e dos processos institucionais que possibilitaram a comercialização das terras e as consequências da colonização privada para pequenos agricultores. Nesse sentido, o estudo confirma a hipótese que a colonização privada ensejou na lógica de produção capitalista latifundiária. O pequeno agricultor do Centro-Sul teve acesso a terra, mas por uma lógica de mercado que possibilitou através das terras devolutas o processo de compra e venda de áreas de tamanhos diversos, até mesmo em quantidades inferiores à permitida pelo órgão oficial do governo. Fomentou a ocupação, o trabalhador rural, principalmente o pequeno também serviu de mão de obra necessária para os grandes projetos capitalistas. Identificou-se que os pequenos produtores não estavam contemplados nos planejamentos das organizações governamentais. A colonização privada empreendida por empresas e famílias se configura como uma continuação da "colonial empresa". A ocupação da Amazônia mato-grossense estabeleceu com a presença das organizações e das instituições públicas e privadas o processo de privatização de terras, tidas por devolutas de Mato Grosso. A burla para a aquisição de terras foi instrumentalizada por leis e organizações que facilitaram a compra junto ao Estado. Essas terras chegaram aos pequenos agricultores do Centro-Sul via comercialização empreendidas pelos colonizadores particulares. Os agricultores migrantes vieram de uma cultura produtiva baseada em um ambiente próprio do sul e sudeste. Em Mato Grosso, enfrentaram dificuldades com o clima e qualidade do solo daqui do Centro-Oeste, gerando uma diferença edafoclimática, limitando a produção agrícola com a cultura que trouxeram. Entre acertos e erros, geraram conhecimentos, próprios de iniciativas endógenas, embora consideram que seu conhecimento de pioneiro não é reconhecido e valorizado nas políticas públicas, que ainda busca assentar pequenos trabalhadores agrícolas.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Bulbophyllum, which comprises 1876 species, is considered the second largest genus of angiosperms, with a pantropical distribution. The morphological and anatomical floral studies in the genus are incipient, with data restricted to the gynostemium and lip of some species. Based on molecular data, six sections were recognized within Bulbophyllum at the Neotropics, amongst them Bulbophyllum sect. Micranthae, which comprises 12 species distributed in central South America. We aimed to study the floral anatomy of six species of Bulbophyllum sect. Micranthae, in order to determine useful characters to differentiate them and contribute to the anatomical characterization of the section as a whole. Floral anatomy was assessed through usual techniques of light microscopy. The data found here for B. adiamantinum, B. chloroglossum, B. epiphytum, B. mentosum, B. micranthum and B. rupicolum allowed to identificate the presence of glandular trichomes and the possible presence of a secretory region on the lip, which might produce substances used as a reward to pollinators. The most significant anatomical characters to the species characterization were the shape and ornamentation of the outer periclinal walls of the epidermal cells, as well as the number of vascular bundles in dorsal and lateral sepals and at the lip. The data also allowed the differentiation between B. epiphytum and B. rupicolum, species very similar in morphology and phylogenetically related. Besides that, the data also allowed the discussion regarding the maintenance of B. mentosum within the section: although its inclusion is supported by molecular studies, the anatomical data here presented shows greater differences compared to the other species, not supporting its maintenance in Bulbophyllum sect. Micranthae

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Pós-graduação em Serviço Social - FCHS

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

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Pós-graduação em Biociências - FCLAS

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The influence of the 1992-1993 El Nino events on the reproductive behavior of the Scomber japonicus peruanus (Chub mackerel) was studied from samples collected monthly, along the Peruvian coast (3 degrees 23`S-14 degrees 00`S), from January 1990 to December 1993. The monthly variation of the gonadosomatic index and the frequency of the periods of gonad maturation evidenced that the spawning of the species occurred all year long, being more intense in summer. The values of the gonadosomatic index were higher during the occurrence of the 1992-1993 El Nino, while the body weight and gonad weight decreased. Regarding the condition factor, its values decreased in females over 35 cm in fork length.

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In order to investigate the climate variability in the northern Antarctic Peninsula region, this paper focuses on the relationship between stable isotope content of precipitation and firn, and main meteorological variables (air temperature, relative humidity, sea surface temperature, and sea ice extent). Between 2008 and 2010, we collected precipitation samples and retrieved firn cores from several key sites in this region. We conclude that the deuterium excess oscillation represents a robust indicator of the meteorological variability on a seasonal to sub-seasonal scale. Low absolute deuterium excess values and the synchronous variation of both deuterium excess and air temperature imply that the evaporation of moisture occurs in the adjacent Southern Ocean. The delta O-18-air temperature relationship is complicated and significant only at a (multi)seasonal scale. Backward trajectory calculations show that air-parcels arriving at the region during precipitation events predominantly originate at the South Pacific Ocean and Bellingshausen Sea. These investigations will be used as a calibration for ongoing and future research in the area, suggesting that appropriate locations for future ice core research are located above 600 m a.s.l. We selected the Plateau Laclavere, Antarctic Peninsula as the most promising site for a deeper drilling campaign.

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The Paraguay Belt in central South America is part of a larger chain of orogenic belts, including the Araguaia Belt to the northeast and potentially the Pampean Belt to the south, which are believed to mark the suture zone of the Clymene Ocean - interpreted amongst the youngest of the Gondwana amalgamation orogens. The post-orogenic Sao Vicente Granite crops out in the northern Paraguay Belt and cuts the basal unit of the deformed and metamorphosed Cuiaba Group. The age of this granite therefore provides a long sort after minimum age for orogenesis within the belt. Dating crystallisation of this important intrusion is challenging due to the presence of considerable common-Pb. However, based on LA-ICPMS dating of more than 100 zircons from three separate samples we interpret a robust crystallisation age for the Sao Vicente batholith at 518 +/- 4 Ma. This age constrains the termination of deformation within the Paraguay Belt and the final accretion of the supercontinent Gondwana. (C) 2011 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

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La difusividad diapicna en el océano es uno de los parámetros más desconocidos en los modelos climáticos actuales. Su importancia radica en que es uno de los principales factores de transporte de calor hacia capas más profundas del océano. Las medidas de esta difusividad son variables e insuficientes para confeccionar un mapa global con estos valores. A través de una amplia revisión bibliográfica hasta el año 2009 del tema se encontró que el sistema climático es extremadamente sensible a la difusividad diapicna, donde el escalado del Océano Pacífico Sur, con una potencia de su coeficiente de difusividad o kv de 0.63, resultó ser más sensible a los cambios en el coeficiente de difusividad diapicna que el Océano Atlántico con una potencia de kv de 0.44 , se pone de manifiesto así la necesidad de esclarecer los esquemas de mezcla, esquemas de clausura y sus parametrizaciones a través de Modelos de Circulación Global (GCMs) y Modelos de Complejidad Intermedia del Sistema Terrestre (EMICs), dentro del marco de un posible cambio climático y un calentamiento global debido al aumento de las emisiones de gases de efecto invernadero. Así, el objetivo principal de este trabajo es comprender la sensibilidad del sistema climático a la difusividad diapicna en el océano a través de los GCMs y los EMICs. Para esto es necesario el análisis de los posibles esquemas de mezcla diapicna con el objetivo final de encontrar el modelo óptimo que permita predecir la evolución del sistema climático, el estudio de todas las variables que influyen en el mismo, y la correcta simulación en largos periodos de tiempo. The diapycnal diffusivity in the ocean is one of the least known parameters in current climate models. Measurements of this diffusivity are sparse and insufficient for compiling a global map. Through a lengthy review of the literature through 2009 found that the climate system is extremely sensitive to the diapycnal diffusivity, where in the South Pacific scales with the 0.63 power of the diapycnal diffusion, in contrasts to the scales with the 0.44 power of the diapycnal diffusion of North Atlantic. Therefore, the South Pacific is more sensitive than the North Atlantic. All this evidenced the need to clarify the schemes of mixing and its parameterisations through Global Circulation Models (GCMs) and Earth Models of Intermediate Complexity (EMICs) within a context of possible climate change and global warming due to increased of emissions of greenhouse gases. Thus, the main objective of this work understands the sensitivity of the climate system to diapycnal diffusivity in the ocean through the GCMs and EMICs. This requires the analysis of possible schemes of diapycnal mixing with the ultimate goal of finding the optimal model to predict the evolution of the climate system, the study of all variables that affect it and the correct simulation over long periods of time.

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This study is on albacore (Thunnus alalunga, Bonnaterre 1788), an epi- and mesopelagic oceanic tuna species cosmopolitan in the tropical and temperate waters of all oceans including the Mediterranean Sea, extending in a broad band between 40°N and 40°S. What it’s known about albacore population structure is based on different studies that used fisheries data, RFLP, mtDNA control region and nuDNA markers, blood lectins analysis, individual tags and microsatellite. At the moment, for T. alalunga six management units are recognized: the North Pacific, South Pacific, Indian, North Atlantic, South Atlantic and Mediterranean stocks. In this study I have done a temporal and spatial comparison of genetic variability between different Mediterranean populations of Thunnus alalunga matching an historical dataset ca. from 1920s composed of 43 individuals divided in 3 populations (NADR, SPAIN and CMED) with a modern dataset composed of 254 individuals and 7 populations (BAL, CYP, LIG, TYR, TUR, ADR, ALB). The investigation was possible using a panel of 94 nuclear SNPs, built specifically for the target species at the University of Basque Country UPV/EHU. First analysis done was the Hardy-Weinberg, then the number of clusters (K) was determined using STRUCTURE and to assess the genetic variability, allele frequencies, the average number of alleles per locus, expected (He) and observed (Ho) heterozygosis, and the index of polymorphism (P) was used the software Genetix. Historical and modern samples gives different results, showing a clear loss of genetic diversity over time leading to a single cluster in modern albacore instead of the two found in historical samples. What this study reveals is very important for conservation concerns, and additional research endeavours are needed.

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To increase the sparse knowledge of long-term Southern Hemisphere (SH) climate variability, we assess an ensemble of 4 transient simulations over the last 500 yr performed with a state-of-the-art atmosphere ocean general circulation model. The model is forced with reconstructions of solar irradiance, greenhouse gas (GHG) and volcanic aerosol concentrations. A 1990 control simulation shows that the model is able to represent the Southern Annular Mode (SAM), and to some extent the South Pacific Dipole (SPD) and the Zonal Wave 3 (ZW3). During the past 500 yr we find that SPD and ZW3 variability remain stable, whereas SAM shows a significant shift towards its positive state during the 20th century. Regional temperatures over South America are strongly influenced by changing both GHG concentrations and volcanic eruptions, whereas precipitation shows no significant response to the varying external forcing. For temperature this stands in contrast to proxy records, suggesting that SH climate is dominated by internal variability rather than external forcing. The underlying dynamics of the temperature changes generally point to a combination of several modes, thus, hampering the possibilities of regional reconstructing the modes from proxy records. The linear imprint of the external forcing is as expected, i.e. a warming for increase in the combined solar and GHG forcing and a cooling after volcanic eruptions. Dynamically, only the increase in SAM with increased combined forcing is simulated.

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Most intense cold surges and associated frost events in southern and southeastern Brazil are characterized by a large amplitude trough over South America extending toward tropical latitudes and a ridge to the west of it over the Pacific Ocean. In this study, potential vorticity (PV) streamers serve to examine the flow condition leading to cold surges. Case studies suggest that several PV anomalies are related to cold surge episodes: (1) the potential vorticity unit (2-PVU) isoline upstream of South America becomes progressively more distorted prior and during the cold surge episode, indicating a flow situation which is conducive for Rossby wave breaking and hence a flow which strongly deviates from zonality; (2) the initial stage of a cold surge episode is characterized by a northward bulging of high-PV air to the east of the Andes, resulting in a PV streamer whose northern end reaches Uruguay and southeastern Brazil; the strong PV gradient on its western flank constitutes a flow configuration that induces and maintains the transport of sub-Antarctic air toward the subtropics; (3) a distinct negative PV anomaly, a blocking, originates over the eastern South Pacific, upstream of the South America sector. A composite analysis of 27 cold surges is performed for stratospheric PV streamer frequency on several isentropic surfaces. It reveals that equatorward wave breaking over South America and the western South Atlantic represents an important potential component of the dynamics of intense cold surges. The indications are most pronounced around the isentropic levels of 320 K and immediately before the day with largest temperature drops over subtropical Brazil.

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The link between high precipitation in Dronning Maud Land (DML), Antarctica, and the large-scale atmospheric circulation is investigated using ERA-Interim data for 1979–2009. High-precipitation events are analyzed at Halvfarryggen situated in the coastal region of DML and at Kohnen Station located in its interior. This study further includes a comprehensive comparison of high precipitation in ERA-Interim with precipitation data from the Antarctic Mesoscale Prediction System (AMPS) and snow accumulation measurements from automatic weather stations (AWSs), with the limitations of such a comparison being discussed. The ERA-Interim and AMPS precipitation data agree very well. However, the correspondence between high precipitation in ERA-Interim and high snow accumulation at the AWSs is relatively weak. High-precipitation events at both Halvfarryggen and Kohnen are typically associated with amplified upper level waves. This large-scale atmospheric flow pattern is preceded by the downstream development of a Rossby wave train from the eastern South Pacific several days before the precipitation event. At the surface, a cyclone located over the Weddell Sea is the main synoptic ingredient for high precipitation both at Halvfarryggen and at Kohnen. A blocking anticyclone downstream is not a requirement for high precipitation per se, but a larger share of blocking occurrences during the highest-precipitation days in DML suggests that these blocks strengthen the vertically integrated water vapor transport (IVT) into DML. A strong link between high precipitation and the IVT perpendicular to the local orography suggests that IVT could be used as a “proxy” for high precipitation, in particular over DML's interior.

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