Efeito da aplicação de alguns herbicidas à pré-emergência sobre a nodulação, a fixação de nitrogênio e o crescimento da soja

Aretit at the recommended rate (XI) and treflan, especially at high concentration (x 5 folds), stimulated nodulation of soybean 'Clark', while planavin, cobex or linuron, especially at high concentration inhibited nodule formation and even, in some instances, prevented plant growth. In all herbicidal treatments, the dry matter content of whole plant on the second harvest (92 days or pod filling) was lower, even those which showed stimulation at the first harvest (49 days or full bloom) than the control; the yields of pods obtained on maturity were also lower. In general, total-N contents of shoots, roots and pods as well as yield of total-N seemed to be affected by the application of herbicides. The effect differed according to herbicides concentration and growth stages of the plant. Nitrogenase activity as a measure of biological fixation of atmospheric nitrogen using the acetylene-reduction technique was also carried out for root nodules to investigate effect of aretit or treflan on the symbiotic N-fixation processes. The dehydrogenase (DHA) activity in nodule homogenate was also determined in presence or absence of succinate, citrate or ethanol to investigate the effect of herbicidal treatments on respiratory chain of bacteroids. This was claimed to thraw light on effect of herbicidal treatments on capacity of the legume plant (soybean 'Clark') to supply the symbiont (R. japonicum) in the root nodules with some products (hydrogen doners) of the Kreb's cycle and consequently thus affects nitrogen fixation efficiency of root nodules.O aretit na dose recomendada (x1), e o treflan, mormente em alta concentração (5 dobras), estimularam a nodulação da soja ‘Clark'. O planavin ou o linuron, mormente em alta concentração, inibiram a formação de nódulos e, em certos casos, até anteciparam o crescimento da planta. Em todos os tratamentos com herbicidas, a quantidade de matéria seca na segunda colheita (92°. dia, período de enchimento da vagem) foi menor do que na testemunha, mesmo em se tratando de plantas que mostraram estimulação na primeira colheita (49°. dia, plena floração). Também as produções de vagens foram menores. Em geral, parece que os conteúdos de N-total dos brotos, raízes e vagens e a própria produção de N-total são favorecidos com o uso de herbicidas. O efeito diferiu de acordo com o grau de concentração dos herbicidas e de acordo também com o estádio de desenvolvimento da planta. Para investigar o efeito do aretit ou do treflan sobre os processos simbióticos de fixação de nitrogénio, foi efetuada, para os nódulos radiculares, no 49°. e 92°. dias, a atividade de nitrogenase, como medida de fixação biológica de nitrogênio atmosférico. Também foi efetuada a atividade de deidrogenase (DHA) em nódulo homogeneizado, em presença ou ausência de succinato, citrato, ou etanol, para investigação do efeito dos tratamentos com herbicidas na corrente respiratória dos bacteroides. Ela foi necessária para se esclarecer o efeito dos tratamentos com herbicidas sobre a capacidade da soja ‘Clark’ de fornecer o simbionte (R. japonicum) nos nódulos radiculares com alguns produtos (doadores de hidrogênio) do ciclo Kreb e, consequentemente, de tornar mais eficiente a fixação de nitrogênio por parte dos nódulos radiculares

Antimicrobial activity and rutin identification of honey produced by the stingless bee Melipona compressipes manaosensis and commercial honey

Background: Honey has been identified as a potential alternative to the widespread use of antibiotics, which are of significant concern considering the emergence of resistant bacteria. In this context, this study aimed to evaluate the antimicrobial activity of honey samples produced by a stingless bee species and by Apis sp. against pathogenic bacteria, as well as to identify the presence of phenolic compounds.Methods: Honey samples from the stingless bee M. compressipes manaosensis were collected twice, during the dry and rainy seasons. Three commercial honey samples from Apis sp. were also included in this study. Two different assays were performed to evaluate the antibacterial potential of the honey samples: agar-well diffusion and broth macrodilution. Liquid-liquid extraction was used to assess phenolic compounds from honey. HPLC analysis was performed in order to identify rutin and apigenin on honey samples. Chromatograms were recorded at 340 and 290 nm.Results: Two honey samples were identified as having the highest antimicrobial activity using the agar diffusion method. Honey produced by Melipona compressipes manaosensis inhibited the growth of Staphylococcus aureus, Escherichia coli (0157: H7), Proteus vulgaris, Shigella sonnei and Klebsiella sp. A sample of honey produced by Apis sp. also inhibited the growth of Salmonella paratyphi. The macrodilution technique presented greater sensitivity for the antibacterial testing, since all honey samples showed activity. Flavonoid rutin was identified in the honey sample produced by the stingless bee.Conclusions: Honey samples tested in this work showed antibacterial activity against Gram-positive and Gram-negative bacteria. The results reported herein highlight the potential of using honey to control bacterial growth. © 2013 Pimentel et al.; licensee BioMed Central Ltd

EEGS Findings Among Adults Sudanese Subjects Presented to the National Ribat University

Background: Epilepsy and seizure are one of the most common serious neurological disorders, and most patients either stop having seizures or less commonly die of them. Methods: This retrospective cross-sectional study targeting adult Sudanese patients was conducted in the EEG units of the department of physiology, faculty of medicine, and the National Ribat University. Recordings were obtained from a digital EEG machine (Medtronic pl-EEG). The Statistical Package for Social Sciences (Windows version 15; SPSS) was used for statistical analysis. The study's main objective was to determine the percentage of abnormal EEGs in adult Sudanese epileptic patients who were referred to the Ribat EEG unit from March 2007 to September 2010. Results: Nine hundred and fifty patients were included in this study, abnormal EEGs was seen in 54.7%, while it was normal was in 45.3%; primary generalized seizures constituted 45.5%, while focal onset seizures were collectively observed in 43.4%, other types of epilepsy counted for 11.2%. Conclusion: This study showed that males were more affected than females, abnormal EEG was maximal in the age group16–30 years. Epileptiform seizure discharges decrease with age, generalized seizure discharges were dominated seizure

EEGS Findings Among Adults Sudanese Subjects Presented to the National Ribat University

Background: Epilepsy and seizure are one of the most common serious neurological disorders, and most patients either stop having seizures or less commonly die of them. Methods: This retrospective cross-sectional study targeting adult Sudanese patients was conducted in the EEG units of the department of physiology, faculty of medicine, and the National Ribat University. Recordings were obtained from a digital EEG machine (Medtronic pl-EEG). The Statistical Package for Social Sciences (Windows version 15; SPSS) was used for statistical analysis. The study's main objective was to determine the percentage of abnormal EEGs in adult Sudanese epileptic patients who were referred to the Ribat EEG unit from March 2007 to September 2010. Results: Nine hundred and fifty patients were included in this study, abnormal EEGs was seen in 54.7%, while it was normal was in 45.3%; primary generalized seizures constituted 45.5%, while focal onset seizures were collectively observed in 43.4%, other types of epilepsy counted for 11.2%. Conclusion: This study showed that males were more affected than females, abnormal EEG was maximal in the age group16–30 years. Epileptiform seizure discharges decrease with age, generalized seizure discharges were dominated seizure

Dilution and temperature effects on ultrafine particle emissions at the exhaust outlet of Diesel and gasoline passenger cars

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