Cytogenetic analysis of Phyllomedusa distincta Lutz, 1950 (2n = 2x = 26), P. tetraploidea Pombal and Haddad, 1992 (2n = 4x = 52), and their natural triploid hybrids (2n = 3x = 39) (Anura, Hylidae, Phyllomedusinae)

Background: Natural polyploidy has played an important role during the speciation and evolution of vertebrates, including anurans, with more than 55 described cases. The species of the Phyllomedusa burmeisteri group are mostly characterized by having 26 chromosomes, but a karyotype with 52 chromosomes was described in P. tetraploidea. This species was found in sintopy with P. distincta in two localities of São Paulo State (Brazil), where triploid animals also occur, as consequence of natural hybridisation. We analyse the chromosomes of P. distincta, P. tetraploidea, and their triploid hybrids, to enlighten the origin of polyploidy and to obtain some evidence on diploidisation of tetraploid karyotype.Results: Phyllomedusa distincta was 2n = 2x = 26, whereas P. tetraploidea was 2n = 4x = 52, and the hybrid individuals was 2n = 3x = 39. In meiotic phases, bivalents were observed in the diploid males, whereas both bivalents and tetravalents were observed in the tetraploid males. Univalents, bivalents or trivalents; metaphase II cells carrying variable number of chromosomes; and spermatids were detected in the testis preparations of the triploid males, indicating that the triploids were not completely sterile. In natural and experimental conditions, the triploids cross with the parental species, producing abnormal egg clutches and tadpoles with malformations. The embryos and tadpoles exhibited intraindividual karyotype variability and all of the metaphases contained abnormal constitutions. Multiple NORs, detected by Ag-impregnation and FISH with an rDNA probe, were observed on chromosome 1 in the three karyotypic forms; and, additionally, on chromosome 9 in the diploids, mostly on chromosome 8 in the tetraploids, and on both chromosome 8 and 9 in the triploids. Nevertheless, NOR-bearing chromosome 9 was detected in the tetraploids, and chromosome 9 carried active or inactive NORs in the triploids. C-banding, base-specific fluorochrome stainings with CMA3 and DAPI, FISH with a telomeric probe, and BrdU incorporation in DNA showed nearly equivalent patterns in the karyotypes of P. distincta, P. tetraploidea, and the triploid hybrids.Conclusions: All the used cytogenetic techniques have provided strong evidence that the process of diploidisation, an essential step for stabilising the selective advantages produced by polyploidisation, is under way in distinct quartets of the tetraploid karyotype. © 2013 Gruber et al.; licensee BioMed Central Ltd.

Caña de azúcar, producción de alcohol y los intereses de las transnacionales en Brasil = Sugar cane, alcohol production and the interests of transnational corporations in Brazil

Incluye Bibliografía

Análise da área da saúde coletiva nas estruturas curriculares dos cursos de odontologia do Brasil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

ECLAC Notes Nº 52

Foreign Investment in Latin America and the Caribbean Increased in 2006 Investment and Corporate Strategies of Korea and Portugal in Latin America and the Caribbean Op ed by ECLAC's Executive Secretary, José Luis Machinea: The Challenge of Attracting Quality Foreign Direct Investment Highlights.Towards the 10th Regional Conference on Women in Latin America and the Caribbean Indicators The Risks and Opportunities of Bioenergy Recent titles Calendar of events

Notas de la CEPAL Nº 52

Crecen flujos de inversión extranjera hacia AméricaLatina y el Caribe en 2006 Inversiones y estrategias empresariales de Corea y Portugal en América Latinay el Caribe Columna de opinión del Secretario Ejecutivo de la CEPAL, José Luis Machinea: El desafío de captar inversión extranjera directa de calidad Precisiones.Hacia la Décima ConferenciaRegional sobre la Mujer de América Latina y el Caribe Indicadores Oportunidades y riesgosde la bioenergía Publicaciones recientes y calendario de eventos

An assessment of the economic impact of climate change on the Agriculture Sector in Jamaica

The agricultural sector‟s contribution to GDP and to exports in Jamaica has been declining with the post-war development process that has led to the differentiation of the economy. In 2010, the sector contributed 5.8% of GDP, and 3% to the exports (of goods), but with 36% of employment, it continues to be a major employer. With a little less than half of the population living in rural communities, agricultural activities, and their linkages with other economic activities, continue to play an important role as a source of livelihoods, and by extension, the economic development of the country. Sugar cane cultivation has, with the exception of a couple of decades in the twentieth century when it was superseded by bananas, dominated the agricultural export sector for centuries as the source of the raw materials for the manufacture of sugar for export. In 2005, sugar cane itself accounted for 6.4% of the sector‟s contribution to GDP, and 52% of the contribution of agricultural exports to GDP. Production for the domestic market has long been the larger subsector, organized around the production of root crops, especially yams, vegetables and condiments. To analyse the potential impact of climate change on the agricultural sector, this study selected three important crops for detailed examination. In particular, the study selected sugar cane because of its overwhelming importance to the export subsector of agriculture, and yam and escallion for both their contribution to the domestic subsector as well as the preeminent role yams and escallion play in the economic activities of the communities in the hills of central Jamaica, and the plains of the southwest respectively. As with other studies in this project, the methodology adopted was to compare the estimated values of output on the SRES A2 and B2 Scenarios with the value of output on a “baseline” Business As Usual (BAU), and then estimate the net benefits of investment in the relevant to climate change for the selected crops. The A2 and B2 Scenarios were constructed by applying forecasts of changes in temperature and precipitation generated by INSMET from ECHAM inspired climate models. The BAU “baseline” was a linear projection of the historical trends of yields for each crop. Linear models of yields were estimated for each crop with particular attention to the influence of the two climate variables – temperature and precipitation. These models were then used to forecast yields up to 2050 (table1). These yields were then used to estimate the value of output of the selected crop, as well as the contribution to overall GDP, on each Scenario. The analysis suggested replanting sugar cane with heat resistant varieties, rehabilitating irrigation systems where they existed, and establishing technologically appropriate irrigation systems where they were not for the three selected crops.

Ferimento facial por projétil de arma de fogo: avaliação dos resultados e complicações de 52 pacientes tratados

Pós-graduação em Odontologia - FOA

Influência do método de síntese no processo de pilarização com titânio de uma esmectita da região amazônica

Amostras de argila esmectítica provenientes do município de Serra Madureira no Estado do Acre foram utilizadas no processo de pilarização. As matrizes natural e pilarizada foram caracterizadas por difração de raios X, espectroscopia no infravermelho com transformada de Fourier, análises térmicas diferencial e gravimétrica, microscopia eletrônica de varredura, espectroscopia de raios X por energia dispersiva e análise textural. As soluções pilarizantes de titânio, Ti(OC₂H₅)₄ e TiCl₄, foram analisadas por espectroscopia no infravermelho com transformada de Fourier. O íon intercalante foi obtido através da reação química entre as soluções de Ti(OC₂H₅)₄ e HCl na proporção aproximada de HCl/Ti=1 e soluções de TiCl₄ em reação com etanol com relação Ti/argila= 25 mmol Ti/g. A intercalação da notronita foi efetuada utilizando-se de dois métodos: com a solução de acido clorídrico incorporada paulatinamente na solução de etóxido de titânio, e utilizando o cloreto de titânio em solução de etanol, com vigorosa agitação a 25 ºC durante 3 h e com calcinação a 450 ºC e 600 ºC. Os resultados de difração de raios X do processo de pilarização mostraram alterações no espaçamento basal de 15,30 Å para 18,76 Å, e na área de superfície específica de 44,37 m²/g para 188,72 m²/g. A estabilidade térmica da argila natural foi otimizada com o processo de pilarização.