947 research outputs found
Selection of bacteria for biological control of Meloidogyne incognita in fig.
A inserção do controle biológico no manejo integrado de M. incognita constitui-se como uma estratégia importante para a cultura da figueira no Brasil, visto que não estão disponíveis nematicidas e porta-enxertos resistentes no país. Entre os biocontroladores, rizobactérias apresentam potencial, pois podem atuar promovendo o crescimento vegetal e ou inibindo os nematoides. Assim, o objetivo desse trabalho foi isolar bactérias com potencial para o biocontrole de M. incognita a partir de raízes de figueira e rochas de folhelhos betuminosos e selecionar isolados mais promissores através de ensaios in vitro. 124 isolados foram obtidos de folhelhos betuminosos e de raízes de figueira e avaliados em ensaios in vitro quanto ao efeito sobre ovos e juvenis de segundo estágio de M. incognita e produção de compostos relacionados ao controle biológico de nematoides. A partir dos resultados obtidos, 14 bactérias foram consideradas mais promissoras, produzindo pelo menos um composto relacionado ao biocontrole de fitonematoides, entre os cinco compostos testados, e altos níveis de mortalidade (78-100%) ou inibição da eclosão (73-100%) dos juvenis de segundo estádio do nematóide. A redução no numero de isolados obtida no presente estudo é importante para viabilizar estudos in vivo confirmando o potencial destas rizobactérias para controle de M. incognita em figueira.The inclusion of biological control in the integrated management of M. incognita was established as an important strategy for the fig tree of culture in Brazil, as they are not available nematicides and rootstocks resistant in the country. Among the biocontrol, rhizobacteria have potential because they can act to promote plant growth and inhibiting or nematodes. The objective of this work was to isolate bacteria with potential for biocontrol of M.
incognita from fig roots and bituminous shale rocks and select the most promising isolated by in vitro assays. 124 isolates were obtained from bituminous shale and fig tree roots and evaluated in vitro tests on the effect on eggs and juveniles of second stage of M. incognita and production of compounds related to the biological control of nematodes. From the results obtained, 14 bacteria were considered more promising, producing at least one compound related to the biocontrol plant parasitic nematode, of the five tested compounds and high levels of mortality (78-100%) or inhibition of hatching (73-100% ) of second stage juveniles of the nematode. The reduction in the number of isolates obtained in this study is important to enable in vivo studies confirming the potential of these rhizobacteria to control M. incognita in fig.Facultad de Ciencias Agrarias y Forestale
Selection of bacteria for biological control of Meloidogyne incognita in fig.
A inserção do controle biológico no manejo integrado de M. incognita constitui-se como uma estratégia importante para a cultura da figueira no Brasil, visto que não estão disponíveis nematicidas e porta-enxertos resistentes no país. Entre os biocontroladores, rizobactérias apresentam potencial, pois podem atuar promovendo o crescimento vegetal e ou inibindo os nematoides. Assim, o objetivo desse trabalho foi isolar bactérias com potencial para o biocontrole de M. incognita a partir de raízes de figueira e rochas de folhelhos betuminosos e selecionar isolados mais promissores através de ensaios in vitro. 124 isolados foram obtidos de folhelhos betuminosos e de raízes de figueira e avaliados em ensaios in vitro quanto ao efeito sobre ovos e juvenis de segundo estágio de M. incognita e produção de compostos relacionados ao controle biológico de nematoides. A partir dos resultados obtidos, 14 bactérias foram consideradas mais promissoras, produzindo pelo menos um composto relacionado ao biocontrole de fitonematoides, entre os cinco compostos testados, e altos níveis de mortalidade (78-100%) ou inibição da eclosão (73-100%) dos juvenis de segundo estádio do nematóide. A redução no numero de isolados obtida no presente estudo é importante para viabilizar estudos in vivo confirmando o potencial destas rizobactérias para controle de M. incognita em figueira.The inclusion of biological control in the integrated management of M. incognita was established as an important strategy for the fig tree of culture in Brazil, as they are not available nematicides and rootstocks resistant in the country. Among the biocontrol, rhizobacteria have potential because they can act to promote plant growth and inhibiting or nematodes. The objective of this work was to isolate bacteria with potential for biocontrol of M.
incognita from fig roots and bituminous shale rocks and select the most promising isolated by in vitro assays. 124 isolates were obtained from bituminous shale and fig tree roots and evaluated in vitro tests on the effect on eggs and juveniles of second stage of M. incognita and production of compounds related to the biological control of nematodes. From the results obtained, 14 bacteria were considered more promising, producing at least one compound related to the biocontrol plant parasitic nematode, of the five tested compounds and high levels of mortality (78-100%) or inhibition of hatching (73-100% ) of second stage juveniles of the nematode. The reduction in the number of isolates obtained in this study is important to enable in vivo studies confirming the potential of these rhizobacteria to control M. incognita in fig.Facultad de Ciencias Agrarias y Forestale
Drought, fire and grazing precursors to large-scale pine forest decline
Aim Temperate forests are currently facing multiple stresses due to climate change, biological invasions, habitat fragmentation and fire regime change. How these stressors interact with each other influences how, when and whether ecosystems recover, or whether they adapt or transition to a different ecological state. Because forest recovery or collapse may take longer than a human lifetime, predicting the outcomes of different stressor combinations remains difficult. A clearer vision of future forest trajectories in a changing world may be gained by examining collapses of forests in the past. Here, we use long-term ecological data to conduct a post-mortem examination of the decline of maritime pine forests (Pinus pinaster Ait.) on the SW Iberian Peninsula 7000-6500 years ago.
Location Portugal and Spain.
Methods We compared four palaeoecological records-two with pine declines and two without-using a multiproxy approach. Bioclimatic differences between the four sites were explored. Proxies for past vegetation and disturbance (fire and grazing) were compared with independent palaeoclimatic records. We performed functional traits analysis and used phase plots to examine the causes of pine decline.
Results The pine decline represents a critical transition in SW Iberia, which lies close to maritime pine's bioclimatic limits. Prolonged drought likely killed trees and suppressed the fires that normally stimulate pine germination and pinewood recovery. Increased grazing pressure facilitated the rapid spread of resprouter shrubs. These competed with pine trees and ultimately replaced them. Our data highlight complex interactions between climate, fire, grazing and forest resilience.
Main Conclusions The pine decline occurred at least a century after post-fire resprouters overtook obligate seeders in the vegetation, constituting an early-warning signal of forest loss. Fire suppression, resprouter encroachment and grazing may threaten the persistence of Mediterranean forests as droughts become more frequent and extreme.PTDC/AAC--CLI/108518/2008info:eu-repo/semantics/publishedVersio
Impact of Italian Ryegrass (\u3cem\u3eLolium multiflorum\u3c/em\u3e Lam.) Management on the Parasite Burden in Sheep
Rhizobacteria potential in the control of Meloidogyne incognita in fig
A figueira é economicamente importante pelo papel social que representa no contexto da agricultura familiar. No entanto, sua viabilidade econômica pode ser comprometida em áreas infestadas pelo nematoide das galhas (Meloidogyne incognita) devido à carência de medidas de controle efetivas e disponíveis. Assim, a inserção do controle biológico no manejo integrado dessa praga constitui-se como uma estratégia importante. As rizobactérias são consideradas biocontroladoras promissoras por promover o crescimento vegetal e/ou inibir a ação parasítica dos fitonematoides sobre as plantas hospedeiras. Dessa forma, objetivou-se com esse trabalho, avaliar o desempenho de 14 isolados bacterianos provenientes da rizosfera de figueira e de rochas de folhelhos betuminosos, no biocontrole de M. incognita em figueira. Mudas de figueira cv. ‘Roxo de Valinhos' microbiolizadas com os isolados bacterianos foram transplantadas em solo naturalmente infestado com M.
incognita. Sete isolados (F08, F25, F71, F76, F78, FB34 e FB59), reduziram significativamente o fator de reprodução do nematoide das galhas (P<0,05) em valores que variaram entre 20 e 49%. Contudo, além de suprimir a multiplicação do patógeno, o isolado F78 (Streptomyces sp.) promoveu aumento do peso de raízes, maiores índices de clorofila e conteúdo das enzimas de resistência peroxidades e polifenol-oxidades, e, redução na concentração de fenóis das figueiras microbiolizadas. Nesse sentido, a condução de trabalhos adicionais nesse patossistema pode possibilitar a melhor compreensão dos mecanismos de atuação das bactérias testadas no biocontrole de M. incognita, além de fornecer informações adicionais para a implementação dessa técnica em um programa de manejo integrado do nematoide das galhas.The fig tree is economically important for the social role it plays in the context of family farming. However, its economic viability can be compromised in infested areas by root-knot nematode (Meloidogyne incognita) due to lack of effective and available control measures. Therefore, the insertion of the biological control on the integrated management of this pest constitutes an important strategy. The rhizobacteria are considered promising biocontrol agents for promoting plant growth and or inhibit the parasitic action of plant-parasitic nematodes in the host plants. So, the aim of this study was to evaluate the performance of 14 bacterial isolates from the rhizosphere of fig and shale rocks in biocontrol of M. incognita in fig. Seedlings of fig plants of cv. 'Roxo de Valinhos' were microbiolized with these bacterial isolates and they were transplanted in soil naturally infested with M. incognita subsequently. Seven isolates (F08, F25, F71, F76, F78, FB34 and FB59) reduced the reproduction factor of the root-knot nematode (P <0.05) at rate ranging between 20 and 49%. Besides to suppress the pathogen reproduction, the isolated F78 (Streptomyces sp.) promoting increasing of root weight, higher chlorophyll contents and content peroxidases and polyphenol oxidases resistance enzymes, and reduction of the phenol concentration of microbiolized fig plants. In this sense, conducting further studies in this pathosystem can enable a better understanding of the action mechanisms of the bacteria tested in the biocontrol of M. incognita, as well as providing additional information for the implementation of this technique in an integrated management program of root-knot nematode.Facultad de Ciencias Agrarias y Forestale
Rhizobacteria potential in the control of Meloidogyne incognita in fig
A figueira é economicamente importante pelo papel social que representa no contexto da agricultura familiar. No entanto, sua viabilidade econômica pode ser comprometida em áreas infestadas pelo nematoide das galhas (Meloidogyne incognita) devido à carência de medidas de controle efetivas e disponíveis. Assim, a inserção do controle biológico no manejo integrado dessa praga constitui-se como uma estratégia importante. As rizobactérias são consideradas biocontroladoras promissoras por promover o crescimento vegetal e/ou inibir a ação parasítica dos fitonematoides sobre as plantas hospedeiras. Dessa forma, objetivou-se com esse trabalho, avaliar o desempenho de 14 isolados bacterianos provenientes da rizosfera de figueira e de rochas de folhelhos betuminosos, no biocontrole de M. incognita em figueira. Mudas de figueira cv. ‘Roxo de Valinhos' microbiolizadas com os isolados bacterianos foram transplantadas em solo naturalmente infestado com M.
incognita. Sete isolados (F08, F25, F71, F76, F78, FB34 e FB59), reduziram significativamente o fator de reprodução do nematoide das galhas (P<0,05) em valores que variaram entre 20 e 49%. Contudo, além de suprimir a multiplicação do patógeno, o isolado F78 (Streptomyces sp.) promoveu aumento do peso de raízes, maiores índices de clorofila e conteúdo das enzimas de resistência peroxidades e polifenol-oxidades, e, redução na concentração de fenóis das figueiras microbiolizadas. Nesse sentido, a condução de trabalhos adicionais nesse patossistema pode possibilitar a melhor compreensão dos mecanismos de atuação das bactérias testadas no biocontrole de M. incognita, além de fornecer informações adicionais para a implementação dessa técnica em um programa de manejo integrado do nematoide das galhas.The fig tree is economically important for the social role it plays in the context of family farming. However, its economic viability can be compromised in infested areas by root-knot nematode (Meloidogyne incognita) due to lack of effective and available control measures. Therefore, the insertion of the biological control on the integrated management of this pest constitutes an important strategy. The rhizobacteria are considered promising biocontrol agents for promoting plant growth and or inhibit the parasitic action of plant-parasitic nematodes in the host plants. So, the aim of this study was to evaluate the performance of 14 bacterial isolates from the rhizosphere of fig and shale rocks in biocontrol of M. incognita in fig. Seedlings of fig plants of cv. 'Roxo de Valinhos' were microbiolized with these bacterial isolates and they were transplanted in soil naturally infested with M. incognita subsequently. Seven isolates (F08, F25, F71, F76, F78, FB34 and FB59) reduced the reproduction factor of the root-knot nematode (P <0.05) at rate ranging between 20 and 49%. Besides to suppress the pathogen reproduction, the isolated F78 (Streptomyces sp.) promoting increasing of root weight, higher chlorophyll contents and content peroxidases and polyphenol oxidases resistance enzymes, and reduction of the phenol concentration of microbiolized fig plants. In this sense, conducting further studies in this pathosystem can enable a better understanding of the action mechanisms of the bacteria tested in the biocontrol of M. incognita, as well as providing additional information for the implementation of this technique in an integrated management program of root-knot nematode.Facultad de Ciencias Agrarias y Forestale
Tuberculosis and airflow obstruction: evidence from the PLATINO study in Latin America
The aim of the present study was to evaluate the association between history of tuberculosis and airflow obstruction.A population-based, multicentre study was carried out and included 5,571 subjects aged >= 40 yrs living in one of five Latin American metropolitan areas: São Paulo (Brazil); Montevideo (Uruguay); Mexico City (Mexico); Santiago (Chile); and Caracas (Venezuela). Subjects performed pre- and post-bronchodilator spirometry and were asked whether they had ever been diagnosed with tuberculosis by a physician.The overall prevalence of airflow obstruction (forced expiratory volume in one second/forced vital capacity post-bronchodilator < 0.7) was 30.7% among those with a history of tuberculosis, compared with 13.9% among those without a history. Males with a medical history of tuberculosis were 4.1 times more likely to present airflow obstruction than those without such a diagnosis. This remained unchanged after adjustment for confounding by age, sex, schooling, ethnicity, smoking, exposure to dust and smoke, respiratory morbidity in childhood and current morbidity. Among females, the unadjusted and adjusted odds ratios were 2.3 and 1.7, respectively.In conclusion, history of tuberculosis is associated with airflow obstruction in Latin American middle-aged and older adults.Univ Fed Pelotas, BR-96020220 Pelotas, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilNatl Inst Resp Dis, Mexico City, DF, MexicoUniv Republica, Montevideo, UruguayCatholic Univ Chile, Santiago, ChileCent Univ Venezuela, Caracas, VenezuelaUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc
Tabagismo em gestantes de área urbana da região Sul do Brasil: 1982 e 1993
OBJETIVO: Avaliar as mudanças na prevalência de tabagismo durante a gravidez na cidade de Pelotas, RS, Brasil, com base nos estudos da população materno-infantil realizados nos anos de 1982 e 1993. METODOLOGIA: Estudo transversal, tendo sido identificados 6.011 e 5.304 recém-nascidos, cujas famílias residiam na área urbana da cidade de Pelotas, respectivamente em 1982 e 1993. RESULTADOS: O tabagismo materno durante a gestação apresentou uma discreta redução de 35,7%, em 1982, para 33,5% em 1993 (p < 0,05). O hábito de fumar esteve inversamente relacionado com a renda e o número de consultas no pré-natal.OBJECTIVE: A comparison between on the prevalence of smoking during pregnancy in 1982 and that in 1993 in Pelotas, Southern Brazil. METHODOLOGY: Cross-sectional study. All hospital deliveries in 1982 and 1993 - corresponding to over 99% of all births in those years - were studied. A total of 6,011 and 5,304 mothers were interviewed, respectively. RESULTS: The prevalence of smoking during pregnancy showed a small decrease from 35.7% in 1982 to 33.5% in 1993 (p < 0.05). In the two years under study, family income and number of antenatal care visits were inversely associated with the prevalence of maternal smoking. The rate of stopping smoking during pregnancy was 20.6%
Quadro epdiemiológico das mortes súbitas na infância em cidades gaúchas (Brasil)
All post-perinatal infant deaths occurring within a one-year period in 10 cities in the State of Rio Grande do Sul (Brazil), the metropolitan area of Porto Alegre included, were investigated in a case-control study. Seventy-two sudden infant deaths (SID) were identified through a complex monitoring system. These were investigated in detail through medical interviews with the children's parents and through the review of medical records. Such deaths were more common in males, during the first three months of life, and in the winter. The comparison of each case with two neighborhood control infants through multiple conditional logistic regression identified the following risk factors: low socio-economic level (measured by family income and maternal education), low birthweight, presence of other children in the household, low maternal age, maternal smoking, and mixed or artificial feeding. None of the 72 deaths had been certified as such by the physicians who filled in the death certificates, the majority of which referred to "bronchopneumonia" as the undereying cause.Foram investigados os óbitos infantis pós-perinatais ocorridos no período de um ano, em 10 cidades gaúchas, incluindo a região metropolitana de Porto Alegre, por meio de estudo de casos e controles. Setenta e duas mortes súbitas na infância (MSI) foram identificadas através de amplo sistema de monitorização de óbitos e investigadas em pormenores através de entrevistas médicas com os pais da criança e revisão de prontuários ambulatoriais e hospitalares. Os óbitos foram mais comuns em meninos, no primeiro trimestre de vida e durante o inverno. A comparação de cada caso de MSI com duas crianças-controle da mesma vizinhança, através de regressão logística condicional múltipla, identificou os seguintes fatores de risco: baixo nível socioeconômico (medido através da renda familiar e da escolaridade materna), baixo peso ao nascer, presença de outras crianças no domicílio, mães jovens e fumantes e aleitamento misto ou artificial. Nenhuma das 72 MSI foi reconhecida como tal pelos médicos que preencheram os atestados de óbito, sendo as mesmas atribuídas predominantemente a "broncopneumonias"
Effectiveness of disinfection with alcohol 70% (w/v) of contaminated surfaces not previously cleaned
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