8 research outputs found

    Agricultural biotechnologogy patents in Brazil: a critical review

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    A difusĂŁo do conhecimento e o estĂ­mulo aos inventores fundamentaram o surgimento do sistema de propriedade intelectual. A proteção aos ativos intelectuais nĂŁo Ă© neutra em seus efeitos sobre empresas e paĂ­ses: exigĂȘncias e custos envolvidos na busca e no e9232335

    Perfil do manejo da cultura de milho no sudoeste do ParanĂĄ

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    Esse trabalho teve por objetivo caracterizar o sistema produtivo da cultura do milho no sudoeste do ParanĂĄ, para subsidiar programas de Pesquisa & Desenvolvimento, alĂ©m de transferĂȘncia de tecnologias regionais. A pesquisa foi realizada durante os anos de 2007 e 2008, sendo baseada na aplicação de um questionĂĄrio para 305 produtores de milho e residentes em alguns municĂ­pios da regiĂŁo sudoeste do ParanĂĄ. Os questionĂĄrios possuĂ­am questĂ”es referentes Ă s caracterĂ­sticas do manejo da cultura e sobre a propriedade rural. Verificou-se que muitos agricultores nĂŁo realizam todas as prĂĄticas adequadas de manejo, necessĂĄrias para um desenvolvimento sustentĂĄvel da cultura do milho. Os principais manejos que interferem na produção de milho sĂŁo a deficiĂȘncia hĂ­drica e controle de plantas daninhas, pragas e doenças. Como aspectos positivos aparece a aquisição de sementes certificadas pela maioria dos agricultores; porĂ©m, o nĂ­vel tecnolĂłgico nĂŁo acompanha as exigĂȘncias genĂ©ticas das bases genĂ©ticas dos hĂ­bridos mais escolhidos pelos agricultores. Contudo, os agricultores estĂŁo interessados na realização de cursos de capacitação e na integração com a Universidade e com os ĂłrgĂŁos de extensĂŁo

    RelaçÔes entre o potencial e a temperatura da folha de plantas de milho e sorgo submetidas a estresse hídrico = Relations between the potential and temperature of the corn and sorghum leafs submitted water stress

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    Para avaliar o comportamento diårio do potencial hídrico em plantas de milho e de sorgo submetidas a estresse hídrico, relacionando com as temperaturas foliar e ambiente, foram cultivadas, em vasos individuais em estufa, cinco plantas de cada espécie. Até o estådio fenológico de quatro folhas, o solo nos vasos foi mantido em capacidade de campo. Entre esse estådio e até próximo ao ponto de murcha a irrigação foi suspensa e foram monitoradas diariamente atemperatura ambiente (Tam), o potencial hídrico da folha (Κfolha) e a temperatura sobre a lùmina foliar (Tfoext). Nas plantas que apresentavam enrolamento das folhas, foram registradas astemperaturas (Tfoint) da face interna do limbo enrolado. Também foram calculadas as médias horårias dos Κ folha para ambas as espécies relacionando-os com a Tfoext, a Tfoint e as diferenças entreessas temperaturas. Ambas as espécies apresentaram comportamentos semelhantes quanto ao Κ folha e entre 13 e 15 horas verificou-se o menor Κ folha. Apesar da significativa relação inversa entrea Tfoext e o seu Κ folha, em milho essa relação não apresenta acuråcia para emprego da Tfoext no monitoramento do status hídrico da planta e a Tfoint é inferior à Tfoext, tornando-se um mecanismoque permite à planta a manutenção de seu metabolismo.To evaluate the daily behavior of the water potential in corn and of sorghum plants submitted to water stress, relating with the leaf and ambient temperature, were cultivated, in individual pots in greenhouse, five plants of each species. The plants were kept at field capacity until they reached the stage of four leaves. Between that stadium and close to the wilting point the irrigation was suspended and were monitored daily the ambient temperature (Tam), the water potential in the leaf (Κ folha) and the temperature on the leaf sheet (Tfoext). The plants whose leaves rolled up had their internal temperature measured (Tfoint). The average time of Κ folha was calculated for both species relating them with Tfoex, Tfoint and thedifferences among those temperatures. Both species presented behaviors similar to Κ folha and between 1pm to 3pm they showed the lowest Κ folha. Despite the significant inverse relationshipbetween Tfoext and Κ folha, in corn, this relationship does not present enough precision to use the measure os Tfoex in the control of the water status of the plant and the Tfoint was inferior to theTfoex, becoming a protection mechanism which allows the plant to maintain its metabolism

    Inbreeding depression of 28 maize elite open pollinated varieties

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    The study of inbreeding depression is important for breeding strategies such as use of inbred progenies or extraction of inbreed lines. A diallel of 28 maize open-pollinated varieties was evaluated in 10 environments in the early 1990s. At the same time, S1 populations for each of the 28 varieties were evaluated in the same 10 experiments (environments). Yield reductions of the populations from S0 to S1 (mean of the 10 environments), varied from 34.6% (CMS-01) to 59.2% (CMS-30), with an average of 49.1%. Inbreeding depression was greater in populations with a wider genetic base, which had never been exposed to inbreeding (CMS-30, BR-107, PH4, Cunha, Saracura, Nitrodent, and Nitroflint). Inbred lines with greater yield means should be obtained from the BR-105, BR-111, CMS-01, CMS-03, BR-106, CMS-14c, and CMS-28 populations. The use of parameter estimates generated by analysis of inbreeding depression, allow to make inferences about frequencies of deleterious alleles in the population. The frequencies of favorable alleles in the parents can be obtained by diallel analysis. The association of these two types of information, can provide a better interpretation of the genetic parameters and also can improve the process of selection of parents for either an intra- or an inter-populational breeding program

    Inbreeding depression of 28 maize elite open pollinated varieties

    No full text
    The study of inbreeding depression is important for breeding strategies such as use of inbred progenies or extraction of inbreed lines. A diallel of 28 maize open-pollinated varieties was evaluated in 10 environments in the early 1990s. At the same time, S1 populations for each of the 28 varieties were evaluated in the same 10 experiments (environments). Yield reductions of the populations from S0 to S1 (mean of the 10 environments), varied from 34.6% (CMS-01) to 59.2% (CMS-30), with an average of 49.1%. Inbreeding depression was greater in populations with a wider genetic base, which had never been exposed to inbreeding (CMS-30, BR-107, PH4, Cunha, Saracura, Nitrodent, and Nitroflint). Inbred lines with greater yield means should be obtained from the BR-105, BR-111, CMS-01, CMS-03, BR-106, CMS-14c, and CMS-28 populations. The use of parameter estimates generated by analysis of inbreeding depression, allow to make inferences about frequencies of deleterious alleles in the population. The frequencies of favorable alleles in the parents can be obtained by diallel analysis. The association of these two types of information, can provide a better interpretation of the genetic parameters and also can improve the process of selection of parents for either an intra- or an inter-populational breeding program

    The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

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    AimThe SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery.MethodsThis was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin.ResultsOverall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P ConclusionOne in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease
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