On the existence and stability of periodic orbits in non ideal problems: General results

In this work, motivated by non-ideal mechanical systems, we investigate the following O.D.E. ẋ = f (x) + εg (x, t) + ε2g (x, t, ε), where x ∈ Ω ⊂ ℝn, g, g are T periodic functions of t and there is a 0 ∈ Ω such that f (a 0) = 0 and f′ (a0) is a nilpotent matrix. When n = 3 and f (x) = (0, q (x 3) , 0) we get results on existence and stability of periodic orbits. We apply these results in a non ideal mechanical system: the Centrifugal Vibrator. We make a stability analysis of this dynamical system and get a characterization of the Sommerfeld Effect as a bifurcation of periodic orbits. © 2007 Birkhäuser Verlag, Basel.

Zircon fission track and U-Pb dating methods applied to São Paulo and Taubaté Basins located in the southeast Brazil

Zircon samples from the Cenozoic São Paulo and Taubaté Basins and Mantiqueira Mountain Range (southeast Brazil) were concomitantly dated by zircon Fission Track Method (FTM) and in situ U-Pb dating method. While FTM detrital-zircon data are ideally used to provide low-temperature information, U-Pb single detrital grain ages record the time of zircon formation in igneous or high grade metamorphic environments. This methodology may be used to study the possible sources of the basins sediments. The results suggest that the São Paulo Basin is composed of sediments from just one source, the Mantiqueira Mountain Range. On the other hand, the Taubaté Basin presents further sediment sources besides the Mantiqueira Mountain Range. © 2012 Elsevier Ltd. All rights reserved.

Polymorphisms in the ghrelin gene and their associations with milk yield and quality in water buffaloes

Ghrelin is a gastrointestinal hormone that acts in releasing growth hormone and influences the body general metabolism. It has been proposed as a candidate gene for traits such as growth, carcass quality, and milk production of livestock because it influences feed intake. In this context, the aim of this study was to verify the existence of polymorphisms in the ghrelin gene and their associations with milk, fat and protein yield, and percentage in water buffaloes (Bubalus bubalis). A group of 240 animals was studied. Five primer pairs were used and 11 single nucleotide polymorphisms (SNP) were found in the ghrelin gene by sequencing. The animals were genotyped for 8 SNP by PCR-RFLP. The SNP g.960G>A and g.778C>T were associated with fat yield and the SNP g.905T>C was associated with fat yield and percentage and protein percentage. These SNP are located in intronic regions of DNA and may be in noncoding RNA sites or affect transcriptional efciency. The ghrelin gene in buffaloes influences milk fat and protein synthesis. The polymorphisms observed can be used as molecular markers to assist selection. © 2013 American Dairy Science Association.

Desarrollo en las áreas marinas y costeras del Gran Caribe: un estudio general = Marine and coastal areas development in the Wider Caribbean: overview study

Incluye Bibliografía

Asentamientos humanos en el área del Gran Caribe: un estudio general = Human settlements in the wider Caribbean

Incluye Bibliografía

Estudio general sobre los recursos naturales renovables para la alimentación y la agricultura en el Gran Caribe = Overview on the state of renewable natural resources for food and agriculture in the Wider Caribbean

Incluye Bibliografía

Estudio general de la higiene ambiental en la zona del Gran Caribe = Overview on environmental health in the Wider Caribbean

Incluye Bibliografía

Development and legal aspects of general insurance in the Caribbean with special reference to the OECS countries

Examina y analiza los principales asuntos legales relacionados al desarrollo y operación de las compañías de seguros generales en el Caribe, con especial referencia a los países de la Organización de Estados del Caribe Oriental.

Proyecto Propuestas para la Transformación Productiva de la Vivienda en América Latina y el Caribe: marco conceptual y metodología general = Project Proposals for Changing Production Patterns in the Housing Sector in Latin America and the Caribbean: conceptual framework and general methodology

Incluye Bibliografía

Transfer of technology in the industrial development of Brazil: general aspects of the problem

Includes bibliography

Adapting the process towards a TSA in Latin America and the Caribbean: a general perspective

Includes bibliography

Comparative cytogenetic analysis in the species Uroderma magnirostrum and U. bilobatum (cytotype 2n = 42) (Phyllostomidae, Stenodermatinae) in the Brazilian Amazon

The genus Uroderma includes two species: U. magnirostrum and U. bilobatum. These species are characterized by their high degree of karyotypic evolution, diverging from most other species of the subfamily Stenodermatinae, which have a lower degree of chromosomic evolution. The present study reports the first banding patterns of U. magnirostrum (G-, C-banding and Ag-NOR) and U. bilobatum (C-banding and Ag-NOR). The chromosomic data in conventional staining of U. magnirostrum (2n = 36, NF = 62) and U. bilobatum (cytotype 2n = 42, NF = 50) are equivalent to that described in the literature. When compared, chromosomal homeologies are found in both karyotypes, as well as differences, confirming that karyotypic evolution in the Uroderma genus is intense. Fission, fusion, inversion or translocation events are required to explain the karyotypic evolution of this genus. The comparison of karyotype, described here, to one of the species of the genus Artibeus (2n = 30/31), suggests that some chromosomic forms are apomorphic and shared between the two species of Uroderma. This confirms the monophyly of the enus, and that U. magnirostrum presents a more primitive karyotype when compared to U. bilobatum