8 research outputs found
Agricultural biotechnologogy patents in Brazil: a critical review
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
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 hĂdrico = Relations between the potential and temperature of the corn and sorghum leafs submitted water stress
Para avaliar o comportamento diĂĄrio do potencial hĂdrico em plantas de milho e de sorgo submetidas a estresse hĂdrico, relacionando com as temperaturas foliar e ambiente, foram cultivadas, em vasos individuais em estufa, cinco plantas de cada espĂ©cie. AtĂ© o estĂĄdio fenolĂłgico de quatro folhas, o solo nos vasos foi mantido em capacidade de campo. Entre esse estĂĄdio e atĂ© prĂłximo ao ponto de murcha a irrigação foi suspensa e foram monitoradas diariamente atemperatura ambiente (Tam), o potencial hĂdrico da folha (Κfolha) e a temperatura sobre a lĂąmina foliar (Tfoext). Nas plantas que apresentavam enrolamento das folhas, foram registradas astemperaturas (Tfoint) da face interna do limbo enrolado. TambĂ©m foram calculadas as mĂ©dias horĂĄrias dos Κ folha para ambas as espĂ©cies relacionando-os com a Tfoext, a Tfoint e as diferenças entreessas temperaturas. Ambas as espĂ©cies 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 nĂŁo apresenta acurĂĄcia para emprego da Tfoext no monitoramento do status hĂdrico da planta e a Tfoint Ă© inferior Ă Tfoext, tornando-se um mecanismoque permite Ă 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
RelaçÔes entre o potencial e a temperatura da folha de plantas de milho e sorgo submetidas a estresse hĂdrico
Inbreeding depression of 28 maize elite open pollinated varieties
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
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
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Effects of pre-operative isolation on postoperative pulmonary complications after elective surgery: an international prospective cohort study an international prospective cohort study
We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05â1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4â7 days or â„ 8 days of 1.25 (1.04â1.48), p = 0.015 and 1.31 (1.11â1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care. We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05â1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4â7 days or â„ 8 days of 1.25 (1.04â1.48), p = 0.015 and 1.31 (1.11â1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care
The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study
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 4âweeks 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 4âweeks. 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%, PÂ =Â 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, PâConclusionOne 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