74 research outputs found

    Controle de plantas daninhas por meio da consorciação com Gliricídia. II. Cultura do milho

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    Um dos principais interesses da agricultura moderna é a redução no uso de herbicidas; para isso, diversas alternativas estão sendo investigadas, inclusive a consorciação. A cobertura do solo com ramos de gliricídia (Gliricidia sepium) não tem efeito alelopático sobre o milho ou feijão, mas diminui significativamente a população de algumas espécies de plantas daninhas. O objetivo deste estudo foi avaliar os rendimentos de espigas verdes e de grãos de cultivares de milho, em resposta ao controle de plantas daninhas, por meio da consorciação com gliricídia. Utilizou-se o delineamento de blocos ao acaso com parcelas subdivididas e cinco repetições. Os cultivares 1051, AG 2060, BRS 2020 e PL 6880 (atribuídos às parcelas) foram submetidos aos seguintes tratamentos: sem capina, duas capinas (realizadas aos 20 e 40 dias após a semeadura) e consorciação com gliricídia. Esta planta foi cultivada em um sistema de transplantio, para garantir germinação uniforme e rápido estabelecimento no campo. A semeadura foi feita em bandejas de 200 células, com uma semente por célula (volume de 35 mL). As plantas emergiram dois a três dias após a semeadura e foram transplantadas para o local definitivo dois a três dias após a emergência. O milho foi semeado no mesmo dia em que a gliricídia foi transplantada. Dezesseis espécies de plantas daninhas ocorreram em diferentes frequências, com distribuição desuniforme na área experimental. Os cultivares AG 1051 e AG 2060 foram os melhores quanto à maioria das características avaliadoras do rendimento de milho verde. O cultivar AG 1051 foi o melhor quanto ao rendimento de grãos. Os maiores rendimentos de espigas verdes e de grãos foram obtidos com duas capinas. Todavia, o fato de as parcelas consorciadas terem apresentado médias intermediárias às médias das parcelas não-capinadas e capinadas – em algumas características avaliadoras do rendimento de espigas verdes e no rendimento de grãos – indica que a gliricídia foi benéfica ao milho e exerceu certo controle sobre as plantas daninhas. _________________________________________________________________________________ ABSTRACTA reduction in herbicide use is one of modern agriculture’s main interests and several alternatives are being investigated with this objective, including intercropping. Gliricídia (Gliricidia sepium) mulch has no allelopathic effect on corn or beans but significantly decreased the population of some weed species. The objective of this study was to evaluate green ear and grain yield in corn cultivars as a response to weed control achieved via intercropping with gliricidia. A completely randomized block design with five replicates and split-plots was used. Cultivars AG 1051, AG 2060, BRS 2020, and PL 6880 (assigned to plots) were submitted to the following treatments: no hoeing, hoeing (performed at 20 and 40 days after sowing the corn), and corn intercropped with gliricidia. Gliricidia was grown in a transplanting system to ensure uniform germination and fast establishment in the field. Seeding was made in 200-cell trays with one seed per cell (35 mL volume). The plants emerged two to three days after sowing and were transplanted to a permanent site two to three days after emergence. Corn was sown on the same day gliricidia was transplanted. Sixteen weed species occurred at different frequencies, with uneven distribution in the experimental area. Cultivars AG 1051 and AG 2060 were the best with reference to most characteristics employed to evaluate green corn yield. Cultivar AG 1051 provided the highest grain yield. The highest green ear yield and grain yield values were obtained with hoeing. However, the fact that intercropped plots showed intermediate yield between the values obtained for hoed and non-hoed plots indicates that gliricidia was beneficial to corn, and exerted a certain level of weed control

    Bienzymatic fluorescence detection based on paraoxonase and laccase on anthracene-sequestered polyamic acid films: A novel approach for inhibition-based sensors

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    A fluorescence assay based on paraoxonase (PO) and laccase (Lac) immobilized on anthracene-sequestered polyamic acid films is now being reported for the first time for ciprofloxacin (CFx) detection. In enzymatic reaction, PO converts phenyl acetate (PA) to acetic acid and phenol. The formed phenol is further oxidized by laccase using oxygen as a co-substrate. For indirectly fluorescence measurements of PA hydrolysis, increased fluorescence intensity was measured after oxygen consumption by laccase. This is because oxygen is quencher of anthracene (Ant) incorporated in the sequestered poly(amic) acid (PAA) film. The detection mechanism was based on inhibition of PO activity by CFx. Using PAA provided the advantage of controlling the film thickness. Firstly, morphology of PAA-Ant polymeric film was characterized by scanning electron microcopy (SEM) and the success of PO-Lac immobilization on PAA-Ant was proven by SEM plus Energy-dispersive X-ray spectroscopy (SEM-EDX) and fluorescence measurements. Then Ant-PAA/PO/Lac is calibrated for PA and CFx without any interfering of some potential interferences. All results make it a promising tool for monitoring CFx at minute levels in samples. © 2020 Elsevier Ltd2017FEN012Authors thank to Ege University Research Foundation (Project no: 2017FEN012) for support

    Purkinje cell number decreases in the adult female rat cerebellum following exposure to 900 MHz electromagnetic field

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    PubMed: 20691167The biological effects of electromagnetic field (EMF) exposure from mobile phones have growing concern among scientists since there are some reports showing increased risk for human health, especially in the use of mobile phones for a long duration. In the presented study, the effects on the number of Purkinje cells in the cerebellum of 16-week (16 weeks) old female rats were investigated following exposure to 900 MHz EMF. Three groups of rats, a control group (CG), sham exposed group (SG) and an electromagnetic field exposed group (EMFG) were used in this study. While EMFG group rats were exposed to 900 MHz EMF (1 h/day for 28 days) in an exposure tube, SG was placed in the exposure tube but not exposed to EMF (1 h/day for 28 days). The specific energy absorption rate (SAR) varied between 0.016 (whole body) and 2 W/kg (locally in the head). The CG was not placed into the exposure tube nor was it exposed to EMF during the study period. At the end of the experiment, all of the female rats were sacrificed and the number of Purkinje cells was estimated using a stereological counting technique. Histopathological evaluations were also done on sections of the cerebellum. Results showed that the total number of Purkinje cells in the cerebellum of the EMFG was significantly lower than those of CG (p < 0.004) and SG (p < 0.002). In addition, there was no significant difference at the 0.05 level between the rats' body and brain weights in the EMFG and CG or SG. Therefore, it is suggested that long duration exposure to 900 MHz EMF leads to decreases of Purkinje cell numbers in the female rat cerebellum. © 2010 Elsevier B.V

    Chronic prenatal exposure to the 900 megahertz electromagnetic field induces pyramidal cell loss in the hippocampus of newborn rats

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    PubMed: 19671630Widespread use of mobile phones which are a major source of electromagnetic fields might affect living organisms. However, there has been no investigation concerning prenatal exposure to electromagnetic fields or their roles in the development of the pyramidal cells of the cornu ammonis in postnatal life. Two groups of pregnant rats, a control group and an experimental group, that were exposed to an electromagnetic field were used. For obtaining electromagnetic field offspring, the pregnant rats were exposed to 900 megahertz electromagnetic fields during the 1–19th gestation days. There were no actions performed on the control group during the same period. The offspring rats were spontaneously delivered—control group (n = 6) and electromagnetic field group (n = 6). Offspring were sacrificed for stereological analyses at the end of the 4th week. Pyramidal cell number in rat cornu ammonis was estimated using the optical fractionator technique. It was found that 900 megahertz of electromagnetic field significantly reduced the total pyramidal cell number in the cornu ammonis of the electromagnetic field group (P < 0.001). Therefore, although its exact mechanism is not clear, it is suggested that pyramidal cell loss in the cornu ammonis could be due to the 900 megahertz electromagnetic field exposure in the prenatal period. © 2009, SAGE Publications. All rights reserved

    THE EFFECT OF EMBRYO TRANSFER LOADING VOLUME ON CLINICAL PREGNANCY RATES IN NORMORESPONDERS UNDERWENT LONG AGONIST PROTOCOL INTRACYTOPLASMIC SPERM INJECTION CYCLES WITH SINGLE EMBRYO TRANSFER

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    International-Federation-of-Fertility-Societies 21st World Congress on Fertility and Sterility / 69th Annual Meeting of the American-Society-for-Reproductive-Medicine -- OCT 12-17, 2013 -- Boston, MAunsal, mesut a/0000-0002-2766-5999WOS: 000342554502103[No abstract available]Int Federat Fertil Soc, Amer Soc Reprod Me

    Toxicity of non-steroidal anti-inflammatory drugs: a review of melatonin and diclofenac sodium association

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    Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used for the purpose of anti-inflammation, antipyretic, and analgesia. For this aim, they are used for the alleviation of pain, fever, and inflammation associated with rheumatoid arthritis, sports injuries, and temporary pain. However, treatment with NSAIDs may be accompanied by adverse effects such as gastrointestinal damage and platelet dysfunction. As with the other NSAIDs, diclofenac sodium (sodium-(o-((2,6-dichlorophenyl)-amino)-phenyl)-acetate) (DS), an NSAID, has potent anti-inflammatory, analgesic, and antipyretic effects. However, treatment with DS may cause some adverse cerebral and cerebellar effects such as convulsions, disorientation, hallucination, and loss of consciousness. Melatonin (MLT) is a free-radical scavenger and possesses antioxidant properties. It has been reported to easily cross the blood-brain barrier, and is found in high concentrations in the brain after exogenous administration. It is also a neuroprotector in a wide range of conditions affecting the central nervous system CNS due to its free-radical scavenging activities and lipophilic-hydrophilic properties. Neuroprotective actions of MLT have been discovered in both in vitro and in vivo, and are a powerful scavenger of oxygen and nitrogen free radicals. Thus, MLT can protect the cell membrane, organelles, and core against free-radical damage. Therefore, it has been postulated that exogenous MLT acts as a neuroprotector contrary to DS neurotoxicity. In this review, we aimed to discuss the possible neuroprotective effects of MLT on DS toxicit
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