Further investigation of the initial fission-track length and geometry factor in apatite fission-track thermochronology

The external detector method (EDM) is a widely used technique in fission track thermochronology (FTT) in which two different minerals are concomitantly employed: spontaneous tracks are observed in apatite and induced ones in the muscovite external detector. They show intrinsic differences in detection and etching properties that should be taken into account. In this work, new geometry factor values, g, in apatite, were obtained by directly measuring the ρed/ρis ratios and independently determined [GQR]ed/is values through the measurement of projected lengths. Five mounts, two of which were large area prismatic sections and three samples composed of random-orientation pieces have been used to determine the g-values. A side effect of applying EDM is that the value of the initial confined induced fission track, L0, is not measured in routine analyses. The L 0-value is an important parameter to quantify with good confidence the degree of annealing of the spontaneous fission tracks in unknown-age samples, and is essential for accurate thermal history modeling. The impact of using arbitrary L0-values on the inference of sample thermal history is investigated and discussed. The measurement of the L0-value for each sample to be dated using an extra irradiated apatite mount is proposed. This extra mount can be also used for determining the g value as an extension of the ρed/ρis ratio method. Eight apatite samples from crystalline basement, with grains at random orientation, were used to determine the g-values. The results found are statistically in agreement with the values found for apatite samples (from Durango, Mexico) measured in prismatic section and also measured at random orientation. There was no observable variation in efficiency regarding crystal orientation, showing that it is relatively safe using non-prismatic grains, especially in samples with paucity of grains, as it is the case of most basin samples. Implications for the ζ-calibration and for the calibration of the direct (spectrometer-based) fission-track dating are also discussed.

Influência do processamento sobre o perfil sensorial e a atividade antioxidante do suco de laranja

Pós-graduação em Alimentos e Nutrição - FCFAR

Estabelecimento de um índice de sensibilidade ambiental ao óleo em ambientes fluviais, com o suporte da ferramenta MORPH

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A contribuição epistemológica canadense para a construção da arquivística contemporânea

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Latin America and the Caribbean in the World Economy 2013: A sluggish postcrisis, mega trade negotiations and value chains: scope for regional action

Incluye bibliografía.

Port-rail integration: challenges and opportunities for Latin America

This issue of FAL Bulletin analyses the role of good modal integration between port facilities and the rail network to ensure port competitiveness.

Latin America and the Caribbean in the World Economy 2014: Regional integration and value chains in a challenging external environment

The 2014 edition of Latin America and the Caribbean in the World Economy: Regional integration and value chains amid challenging external conditions has four chapters. Chapter I examines the main features of the international context and their repercussions for world and regional trade. Chapter II looks at Latin American and Caribbean participation in global value chains and confirms that the region, with the exception of Mexico and Central America, has only limited linkages with the three major regional value chains of Asia, Europe and North America. This chapter also looks at how participation in value chains may contribute to more inclusive structural change, by analysing three core microeconomic aspects. Chapter III identifies various spheres in which regional integration and cooperation can help strengthen production integration between the economies of Latin America and the Caribbean. The fourth chapter explores the intra- and extraregional trade relations of the countries of the Caribbean Community (CARICOM) and considers how to strengthen production integration in the subregion by taking advantage of linkages beyond trade and building on commercial and production complementarities among the members. The chapter also reviews the differences between the countries in terms of income, population and production and export structure, in a context of marked macroeconomic vulnerability.

An Assessment Of The Economic Impact Of Climate Change On The Transportation Sector In Montserrat

.--I. Introduction.--II. Literature review regarding climate change impacts on international transportation.--III. Economy of the Caribbean subregion and Monserrat.--IV. The international transportaion system in the Caribbean and in Monserrat.--V. Vulnerabilities of international transport system in Monserrat to climate change.--VI. Modelling.-- VII. Economic impact analysis of climate chage on the international transport.-- VIII. Approaches to mitigation and adaptation in the air and sea transportation sectors.-- IX. Conclusions

Qualidade fisiológica da semente e adubação com zinco na cultura do milho-doce

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

Zaprionus indianus: uma visão da espécie invasora sob o aspecto genético e evolutivo

Pós-graduação em Genética - IBILCE

Diplomacia, integração e desenvolvimento: Brasil e Argentina (1950-1962)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A pedra e a água: uma leitura comparada de Pedro Páramo (1955), de Juan Rulfo, e Como água para chocolate (1989), de Laura Esquivel

Pós-graduação em Letras - FCLAS

O romance, leituras da história: a saga de Cristóvão Colombo em terras americanas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Filogenia molecular dos xenarthra (Mammalia): análise do grupo cingulata a partir de sequências nucleotídicas do gene mitocondrial rRNA 16S

Os Xenarthra são o grupo de mamíferos que inclui os tatus, os tamanduás e as preguiças. A América do Sul serviu de cenário para a história natural do grupo que, somente no fim do Cenozóico, dispersou-se para a América Central e, com uma perda de variedade, chegou à América do Norte e à algu-mas ilhas do Caribe. Trinta e uma espécies estão descritas dentro da linha-gem dos Xenarthra. Elas estão classificadas em 13 gêneros, quatro famílias (Bradypodidae, Megalonychidae, Myrmecophagidae e Dasypodidae) e duas ordens (Cingulata e Pilosa). A filogenia deste grupo tem sido alvo de diver-sas pesquisas que analisaram tanto dados morfológicos, quanto moleculares. Delsuc et al. (2003) analisaram seqüências de genes mitocondriais e nucleares e confirmaram a monofilia das três subfamílias (Dasypodinae, Euphacti-nae e Tolypeutinae) inclusas na família Dasypodidae. Delsuc et al. (2003) geraram a seguinte árvore: (((Bradypus, Choloepus)100, ((Myrmecophaga, Tamandua)100, Cyclopes)100), ((D. kappleri, D. novemcinctus)100, (Toly-pentes, (Priodontes, Cabassous)54)100, (Zaedyus, (Euphractus, Chaetophrac-tus)60)100)). Gaudin (2005) apresentou um trabalho que reviu e ampliou as análises morfológicas apresentadas até então, concluindo que os tatus atu-ais estão divididos em dois grupos, um mais basal (Dasypodinae) e outro mais derivado (Euphractinae), de acordo com o seguinte arranjo: (Bradypus, Tamandua), (Dasypus, (Priodontes, (Cabassous, (Tolypeutes, (Euphractus, Chaetophractus, (Zaedyus, Chlamyphorus)42)36)72)72)40)85). Neste traba-lho utilizou-se parte do gene mitocondrial rRNA 16S de 12 táxons atu-ais de Xenarthra para analisar a filogenia do grupo através do critério de máxima verossimilhança. Nossos resultados são apresentados analisando-se o gene 16S e analisando o banco de dados do 16S mais o de Delsuc et al. (2003). Nas duas situações, as filogenias apresentadas apóiam os resulta-dos de Delsuc et al. (2003): (Bradypus, (Choloepus, ((Cyclopes, (Myrme-cophaga, Tamandua)100)100, (Dasypus, (((Cabassous, Priodontes)68, Toly-peutes)100,((Chaetophractus, Euphractus)65, Zaedyus)100)100)100)100)100). Uma melhora nos valores de bootstrap nos ramos dentro das sub-famílias da família Dasypodidae é percebida em relação ao trabalho de Delsuc et al. (2003). Acreditamos que Elementos de Transposição do tipo (LINES) são os marcadores moleculares mais adequados para confirmar o arranjo obtido com as seqüências de genes mitocondriais e nucleares.

Home range and habitat selection by the tropical screech-owl in a Brazilian savanna

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)