10 research outputs found

    Divergência genética e correlações entre variáveis tecnológicas da população de trabalho de bacuri da Embrapa Meio-Norte.

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    Estudou-se a divergência genética e as correlações entre as variáveis agroindustriais dos genótipos da coleção de trabalho do bacuri visando à obtenção de população-base para o seu programa de melhoramento genético na Embrapa Meio-Norte. Essa coleção é constituída de 49 genótipos coletados em áreas de ocorrência natural da espécie nos Estados do Piauí e Maranhão. O experimento foi delineado em blocos completos casualizados com 1 planta por parcela e 5 repetições. As variáveis avaliadas foram: peso, comprimento e diâmetro de frutos; relação comprimento/diâmetro de fruto; número de sementes; porcentagens de polpa, de casca e de sementes; sólidos solúveis totais (SS) e acidez total titulável (ATT). Utilizou-se a análise de agrupamento UPGMA para a separação dos genótipos. Considerando-se a distância média entre clusters de 1,0, os genótipos formaram quatro grupos dissimilares. As variáveis diâmetro e comprimento do fruto podem gerar inferências para a variável peso do fruto e promover uma seleção indireta para esta variável

    Pervasive gaps in Amazonian ecological research

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    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Can Ultrasound or pH Influence Pd Distribution on the Surface of HAP to Improve Its Catalytic Properties in the Dry Reforming of Methane?

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    The influence of ultrasound and different pH pre-treatments during the metal doping/modification of a hydroxyapatite (HAP) support is investigated. HAP is first synthesised via a hard-template synthetic route using carbon nanorods followed by their full physiochemical characterisation. The HAP was found to be crystalline and comprised a mesoporous structure as observed via XRD and nitrogen adsorption with a BET surface area of 97.57 (±1.16) m2 g−1. Ultrasound-assisted ion exchange (IE) and incipient wetness impregnation (IW) methodologies were employed to decorate the surface of HAP with Pd0 and are compared to previous procedures. The influence of pH upon the distribution of Pd0 throughout the samples during the doping process is also studied. All the prepared samples were evaluated for their catalytic activity towards dry reforming of methane (DRM) and the reaction was monitored via a thermal conductivity detector, coupled with gas chromatography (GC-TCD). It was found that ultrasound-assisted IE significantly accelerated the process from 3 days to 3 h and with the Pd0 metal remaining highly distributed upon the HAP with minor changes in catalytic conversions. Moreover, the ultrasound-assisted IW method successfully improved the Pd0 distribution and catalytic performance. On the other hand, the dispersion of the metal was unaffected after pH treatments in IE with no catalytic improvements observed, in contrast to IW, where considerable increase in metal distribution and subsequently catalytic performance was observed

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Produtividade de linhagens avançadas de amendoim em condições de sequeiro no nordeste Brasileiro

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    Onze linhagens avançadas de amendoim, eretas e rasteiras, foram conduzidas em condições de sequeiro, em quatro estados nordestinos, visando-se avaliar a produtividade em vagens e sementes. Os ensaios foram conduzidos no período de 2005 a 2007, nos municípios de Araripina e Parnamirim, PE, Lagarto, SE, Cruz das Almas e Caetité, BA, Campina Grande e Itabaiana, PB. O delineamento experimental adotado foi em blocos ao acaso, com 13 tratamentos, constituídos de oito linhagens eretas e cinco rasteiros, com cinco repetições. As variáveis analisadas foram produtividades de vagens e de sementes. Em referência à análise estatística, realizaram-se análises de variância individual e conjunta e se adotou o teste de Tukey (p < 0,05) para comparação das médias dos tratamentos. A cultivar BR 1 foi utilizada como testemunha entre os genótipos eretos. A linhagem ereta LN-1B apresentou maior produção de vagens entre as demais do grupo, com 2.450 kg ha-1, superando a média em 22% e a BR 1, em 11%; a produtividade média em sementes situou-se em 1.665 kg ha-1, correspondendo a 21% acima da média do grupo e 10% acima da BR 1. Entre as linhagens rasteiras as médias de produtividade em vagens e em sementes foram consideradas baixas nas condições estudadas destacando-se, contudo, LI-3, LI-5 e LI-1, que produziram em média entre 1.722 kg ha-1 e 1.154 kg ha-1, e superaram a média do grupo em 9.8 e 10%, respectivamente

    Divergência genética e correlações entre variáveis tecnológicas da população de trabalho de bacuri da Embrapa Meio-Norte.

    Get PDF
    Estudou-se a divergência genética e as correlações entre as variáveis agroindustriais dos genótipos da coleção de trabalho do bacuri visando à obtenção de população-base para o seu programa de melhoramento genético na Embrapa Meio-Norte. Essa coleção é constituída de 49 genótipos coletados em áreas de ocorrência natural da espécie nos Estados do Piauí e Maranhão. O experimento foi delineado em blocos completos casualizados com 1 planta por parcela e 5 repetições. As variáveis avaliadas foram: peso, comprimento e diâmetro de frutos; relação comprimento/diâmetro de fruto; número de sementes; porcentagens de polpa, de casca e de sementes; sólidos solúveis totais (SS) e acidez total titulável (ATT). Utilizou-se a análise de agrupamento UPGMA para a separação dos genótipos. Considerando-se a distância média entre clusters de 1,0, os genótipos formaram quatro grupos dissimilares. As variáveis diâmetro e comprimento do fruto podem gerar inferências para a variável peso do fruto e promover uma seleção indireta para esta variável

    CD4+CD45RA−FOXP3low Regulatory T Cells as Potential Biomarkers of Disease Activity in Systemic Lupus Erythematosus Brazilian Patients

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    Heren, we analyzed Treg cells as potential biomarkers of disease activity in systemic lupus erythematosus (SLE) patients. Peripheral blood mononuclear cells from 30 SLE patients (15 active: SLEDAI > 6/15 SLE remission: SLEDAI< 6) and 15 healthy volunteers were purified. Treg immunophenotyping was performed using CD4, CD25, CD45, CD127, and FOXP3 markers. CD4+FOXP3+ Treg activation state was investigated based on CD45RA and FOXP3 expression. To increase the accuracy of our findings, a multivariate linear regression was performed. We showed a significant increase in the frequency of CD4+FOXP3+ Treg cells in SLE patients. However, unlike all other Treg cells phenotypes analyzed, only eTreg (CD4+FOXP3highCD45RA-) (p=0.01) subtype was inversely correlated with disease activity while Foxp3+nontreg (CD4+FOXP3lowCD45RA-) (p=0.003) exerted a direct influence in the outcome of the disease. Foxp3+nontreg cells were the most consistent SLE active indicator, confirmed by multiple linear regression analyses. In summary, our results demonstrate Foxp3+nontreg cells as new biomarkers in the search of an effective therapeutic strategy in SLE
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