1,252 research outputs found

    Genetic Structure And Molecular Diversity Of Cacao Plants Established As Local Varieties For More Than Two Centuries: The Genetic History Of Cacao Plantations In Bahia, Brazil

    Get PDF
    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Bahia is the most important cacao-producing state in Brazil, which is currently the sixth-largest country worldwide to produce cacao seeds. In the eighteenth century, the Comum, Para and Maranhao varieties of cacao were introduced into southern Bahia, and their descendants, which are called 'Bahian cacao' or local Bahian varieties, have been cultivated for over 200 years. Comum plants have been used to start plantations in African countries and extended as far as countries in South Asia and Oceania. In Brazil, two sets of clones selected from Bahian varieties and their mutants, the Agronomic Institute of East (SIAL) and Bahian Cacao Institute (SIC) series, represent the diversity of Bahian cacao in germplasm banks. Because the genetic diversity of Bahian varieties, which is essential for breeding programs, remains unknown, the objective of this work was to assess the genetic structure and diversity of local Bahian varieties collected from farms and germplasm banks. To this end, 30 simple sequence repeat (SSR) markers were used to genotype 279 cacao plants from germplasm and local farms. The results facilitated the identification of 219 cacao plants of Bahian origin, and 51 of these were SIAL or SIC clones. Bahian cacao showed low genetic diversity. It could be verified that SIC and SIAL clones do not represent the true diversity of Bahian cacao, with the greatest amount of diversity found in cacao trees on the farms. Thus, a core collection to aid in prioritizing the plants to be sampled for Bahian cacao diversity is suggested. These results provide information that can be used to conserve Bahian cacao plants and applied in breeding programs to obtain more productive Bahian cacao with superior quality and tolerance to major diseases in tropical cacao plantations worldwide.1012Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundacao de Amparo a Pesquisa do Estado da Bahia (FAPESB) [DTE0035/2013]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2008/52197-4, 2010/50033-4, 2013/08086-1

    Enhanced lithium depletion in Sun-like stars with orbiting planets

    Full text link
    The surface abundance of lithium on the Sun is 140 times less than protosolar, yet the temperature at the base of the surface convective zone is not hot enough to burn Li. A large range of Li abundances in solar type stars of the same age, mass and metallicity is observed, but theoretically difficult to understand. An earlier suggestion that Li is more depleted in stars with planets was weakened by the lack of a proper comparison sample of stars without detected planets. Here we report Li abundances for an unbiased sample of solar-analogue stars with and without detected planets. We find that the planet-bearing stars have less than 1 per cent of the primordial Li abundance, while about 50 per cent of the solar analogues without detected planets have on average 10 times more Li. The presence of planets may increase the amount of mixing and deepen the convective zone to such an extent that the Li can be burned.Comment: 13 pages, 2 figure

    Genetic structure and molecular diversity of cacao plants established as local varieties for more than two centuries: the genetic history of cacao plantations in Bahia, Brazil

    Get PDF
    ahia is the most important cacao-producing state in Brazil, which is currently the sixth-largest country worldwide to produce cacao seeds. In the eighteenth century, the Comum, Pará and Maranhão varieties of cacao were introduced into southern Bahia, and their descendants, which are called ‘Bahian cacao’ or local Bahian varieties, have been cultivated for over 200 years. Comum plants have been used to start plantations in African countries and extended as far as countries in South Asia and Oceania. In Brazil, two sets of clones selected from Bahian varieties and their mutants, the Agronomic Institute of East (SIAL) and Bahian Cacao Institute (SIC) series, represent the diversity of Bahian cacao in germplasm banks. Because the genetic diversity of Bahian varieties, which is essential for breeding programs, remains unknown, the objective of this work was to assess the genetic structure and diversity of local Bahian varieties collected from farms and germplasm banks. To this end, 30 simple sequence repeat (SSR) markers were used to genotype 279 cacao plants from germplasm and local farms. The results facilitated the identification of 219 cacao plants of Bahian origin, and 51 of these were SIAL or SIC clones. Bahian cacao showed low genetic diversity. It could be verified that SIC and SIAL clones do not represent the true diversity of Bahian cacao, with the greatest amount of diversity found in cacao trees on the farms. Thus, a core collection to aid in prioritizing the plants to be sampled for Bahian cacao diversity is suggested. These results provide information that can be used to conserve Bahian cacao plants and applied in breeding programs to obtain more productive Bahian cacao with superior quality and tolerance to major diseases in tropical cacao plantations worldwide1012CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP620239/2008-5; 555432/2009-2PROCAD-NF20082008/52197-4; 2010/50033-4; 2013/08086-

    Molecular Genetic Variability Of Commercial And Wild Accessions Of Passion Fruit (passiflora Spp.) Targeting Ex Situ Conservation And Breeding.

    Get PDF
    Passiflora species are distributed throughout Latin America, and Brazil and Colombia serve as the centers of diversity for this genus. We performed cross-species amplification to evaluate 109 microsatellite loci in 14 Passiflora species and estimated the diversity and genetic structure of Passiflora cincinnata, Passiflora setaceae and Passiflora edulis. A total of 127 accessions, including 85 accessions of P. edulis, a commercial species, and 42 accessions of 13 wild species, were examined. The cross-species amplification was effective for obtaining microsatellite loci (average cross-amplification of 70%). The average number of alleles per locus (five) was relatively low, and the average diversity ranged from 0.52 in P. cincinnata to 0.32 in P. setacea. The Bayesian analyses indicated that the P. cincinnata and P. setacea accessions were distributed into two groups, and the P. edulis accessions were distributed into five groups. Private alleles were identified, and suggestions for core collections are presented. Further collections are necessary, and the information generated may be useful for breeding and conservation.1522933-5

    A utilização de recursos criativos para o ensino da literatura infanto-juvenil

    Get PDF
    A literatura infantil vem se transformando constantemente. A palavra literatura é intransitiva e, independente do adjetivo que receba, é uma arte que deve ser contemplada em todas as suas dimensões. Para aprimorar essa arte, faz-se necessário o uso de recursos didáticos que envolvam os educando de forma que estes sejam capazes de navegar nas asas da imaginação em busca de um novo saber. Sabe-se que a Literatura Infantil, por iniciar o homem no mundo literário, deve ser utilizada como instrumento para a sensibilização da consciência, para a expansão da capacidade e interesse de analisar o mundo. Sendo fundamental mostrar que a literatura deve ser encarada, sempre, de modo global e complexo em sua ambigüidade e pluralidade. Nesse contexto este trabalho buscou, refletir sobre o papel das instituições responsáveis pela promoção da Literatura e a formação do homem, analisando a prática desenvolvida na escola pelo profissional de educação e a contribuição da família para que desempenhem eficazmente o papel de incentivadores do hábito e do gosto pela leitura nas séries iniciais do Ensino Fundamental. Para atingir este objetivo, optou-se pela pesquisa teórica ou bibliográfica, por ser bastante apropriada para esta temática. Este estudo foi de caráter exploratório e destaca o método dialético, usando material elaborado, constituído principalmente de livros e artigos de periódicos, publicados, por diversos autores, que tratam do tema ou exploram áreas afins. O processo de análise e interpretação dos dados encontrados na literatura, especialmente em ZILBERMAN (1993, 1998, 1988,1994), Lajolo (1984), Coelho (2000), possibilitou situar a Literatura Infantil no contexto histórico e relacionando com os recursos didáticos necessários para o desenvolvimento do educando no ambiente escolar

    Reorganizando o Laboratório de Ciências: uma experiência da abordagem do PIBID/UESC de Química no espaço escolar

    Get PDF
    A formação de professores de Química tem sido discutida por diversos profissionais da educação que buscam, dentre outras coisas, apresentar os aspectos que estão envolvidos nesse processo. Sendo assim, o intuito deste trabalho é apresentar os resultados obtidos com a intervenção do PIBID/Química UESC em que houve a reorganização de um laboratório de Ciências e esta atividade foi relacionada à formação dos licenciandos envolvidos. Pretendemos também demonstrar a importância deste espaço para a formação de conceitos de Ciências, mas precisamente de Química. Para tal, executamos uma atividade em grupo onde a reorganização deste laboratório foi o foco principal, além da aplicação de um questionário buscando conhecer as impressões dos alunos a cerca do local. Pudemos então perceber que o laboratório de Ciências é um local onde os saberes de Química podem ser construídos e que a atividade por nós realizada teve implicações significativas para nossa formação como licenciandos em Químic

    Influence of different beverages on the force degradation of intermaxillary elastics: an in vitro study

    Get PDF
    OBJECTIVE: The aim of this study was to evaluate in vitro the effects of frequently ingested beverages on force degradation of intermaxillary elastics. MATERIAL AND METHODS: One hundred and eighty 1/4-inch intermaxillary elastics (TP Orthodontics) were immersed into six different beverages: (1) Coca-Cola(®); (2) Beer; (3) Orange juice; (4) Red wine; (5) Coffee and (6) artificial saliva (control). The period of immersion was 15 min for the first and second cycles and 30 min for the third to fifth cycles. Tensile forces were read in a tensile testing machine before and after the five immersion cycles. One-way repeated measures ANOVA was used to identify significant differences. RESULTS: Force degradation was seen in all evaluated groups and at all observation periods (p<0.05). A greater degree of degradation was present at the initial periods, decreasing gradually over time. However, no statistically significant differences were seen among groups at the same periods, showing that different groups behaved similarly. CONCLUSION: The chemical nature of the evaluated beverages was not able to influence the degree of force degradation at all observation periods

    Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

    Get PDF
    Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets
    corecore