88 resultados para Green algae


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The aim of this study was to identify the relation between the evapotranspirometer demand and the supply of water from local rainfall, evaluating the possibility of using water excess for irrigation of Green Roofs in the State of Mato Grosso, in Brazil. The study was done using a series of historical data provided by the National Institute of Meteorology (INMET - Instituto Nacional de Meteorologia) which has official climatological stations in 12 cities and regions of the State. The evapotranspiration values were obtained by the Penman-Monteith method and by the Climatic Water Balance (CWB) by the Thornthwaite and Mather method using Available Water Capacity (AWC) of 12mm. With the CWB the excess and deficit were calculated, which were used for the estimative of the volume and area of a reservoir as a function of a collector area of a roof of 100m² and the volume of supplementary water for irrigation. With the obtained results, it was found that in most investigated regions of the State the use of green roofs is not compromised by the water deficiency. On the other hand, the use of a reservoir to accumulate the rain water excess may be impractical, because it requires a considerable area for installation and also because of the high cost of the land.

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Blood profiles were determined in 47 juvenile green turtles, Chelonia mydas, from São Paulo northern coast, Brazil. Twenty-nine were affected by fibropapillomas and 18 were tumor free. Complete gross and histopathologic examinations of the fibropapillo were performed in 21 green turtles. Biometrical data, size, location and amount of tumors were recorded. The papillomas varied in morphology, location, size, color and texture. We found hyperplastic stroma, rich in blood vessels and connective tissue with increase in thickness of the dermis. The tumors w0ere classified as papillomas or fibropapillomas according to their epithelial and/or stromal proliferation. The lowest Mean Corpuscular Hemoglobin (HCM) values were observed in affected turtles.

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The objective of this work was to evaluate the influence of weeding frequency on cultivar Centralmex green corn yield. Two experiments were conducted in Mossoró-RN (Brazil), with the use of sprinkler irrigation. A random block design with four replicates was used. It was observed that the total number and weight (TW) of unhusked green ears, the number and weight of marketable unhusked ears and the number and weight of marketable husked ears were reduced under no weeding treatment. The number timing of weedings did not influence green corn yield, except for one weeding at 60 DAP, which was equivalent to the "no weeding" treatment, for TW. When maize is marketed considering the total number of green ears, higher net income is obtained when one weeding is carried out 45 days after planting.

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Studies on plant growth are interesting because they provide explanations for the factors that influence yield in various crops. The objective of this work was to evaluate growth and yield in corn cultivar AG1051, when in competition with weeds. Cultivar AG 1051 was submitted to two groups of treatments: weed control, and sampling periods for dry biomass evaluation. The weed control treatments consisted of hoeing (two hoeings performed at 20 and 40 days after sowing) and no hoeing. Sampling periods consisted of collecting the above-ground part and roots of corn every fifteen days, until 105 days after sowing (DAS); the first sampling was performed 30 DAS. A completely randomized block design with ten replicates was used. For the characteristics evaluated in a single season, statistical analyses were carried out as a random block experiment. For the characteristics evaluated in several periods, statistical analyses were carried out as random blocks with split-plots (weed control assigned to plots). Fourteen weed species, unevenly distributed throughout the experimental area, were the most important. The growth observed for the above-ground part and root system of corn was 30% smaller in the non-hoed plots, compared to the hoed plots. Lack of weed control increased dry matter of the above-ground part of the weeds and reduced the number of unhusked and husked marketable green ears by 23% and 49%, respectively. Grain yield reduction caused by lack of weed control reached 38%.

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The reduction in herbicide use is one of the greatest interests for modern agriculture and several alternatives are being investigated with this objective, including the adoption of cultivars that suppress weeds. The objective of this study was to verify if maize cultivars develop differently, in competition with weeds, to produce green ears and grain. Randomized complete block design was used, with split-plots and five replications. Cultivars DKB 390, DKB 466, DKB 350, AG 7000, AG 7575 and Master, were evaluated in the plots, without weeding and two weedings (at 22 and 41 days after sowing) in sub plots. Twenty-one species were identified in the experimental area, the most frequent being Gramineae (Poaceae), Euphorbiaceae, Leguminosae (Fabaceae) and Convolvulaceae species. There was no difference in the dry biomass above-ground part of the weeds in the plots of the evaluated cultivars. The cultivars behaved similarly in treatments with or without hoeing, except for plant height and ear height evaluations. Without hoeing, plant height increased in cultivar DKB 390, while plant height and ear height decreased in cultivar AG 7575. In the other cultivars, these traits did not change under weed control. The presence of weeds decreased the values of all traits employed to assess green corn yield, with the exception of the total number of green ears and grain yield.

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The aim of this study was to assess the efficacy of S-metolachlor applied in pre-emergence conditions for the control of Brachiaria decumbens, Digitaria horizontalis, and Panicum maximum in sugar cane mechanically harvested without previous burning of the crop (green harvest) with the crop residue either left or not on the soil surface. The experiments were established in the field according to a randomized complete block design with four repetitions in a 7 x 2 split-plot scheme. In the plots, five herbicide treatments were studied (S-metolachlor at 1.44, 1.92, and 2.40 kg ha-1, clomazone at 1.20 kg ha-1, and isoxaflutole at 0.188 kg ha-1), and two control treatments with no herbicide application. In the subplots, the presence or absence of sugar cane crop residue on the soil surface was evaluated. S-metolachlor efficacy was not hampered by either 14 or 20 t ha-1 of sugar cane crop residue on the soil surface. When sugar cane crop residue was covering the soil surface, S-metolachlor at a rate of 1.44 kg ha-1 resulted in weed control similar at their larger rates, where as without the presence of crop residue, S-metolachlor controlled B. decumbens, D. horizontalis, and P. maximum at the rates of 1.92, 1.44, and 1.92 kg ha-1, respectively. The herbicides clomazone and isoxaflutole were effective for the studied species, independently of the crop residue covering the soil surface. S-metolachlor caused no visible injury symptoms to the sugar cane plant. Clomazone and isoxaflutole caused visible injuries to the sugar cane plant. None of the herbicides negatively affected the number of viable culms m² or the culm height and diameter.

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Green sugarcane harvesting may promote great changes in the dynamics of herbicides in the environment. Our goal was to evaluate the influence of straw decomposition degree on leaching and weed (Ipomoea grandifolia) control efficacy by (14C) tebuthiuron and hexazinone. The presence of straw on the soil surface affected leaching, mainly for hexazinone (leaching reduced from 37 to 5% of the applied amount in the presence of straw). Overall, tebuthiuron showed more efficient control of Ipomoea than hexazinone. The straw decomposition degree affected only hexazinone efficacy that was lowest for the least decomposed straw. Further studies are needed to evaluate the effects of sugarcane straw on herbicides dissipation, particularly on volatilization and photolysis, to better predict their efficacy and environmental fate.

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Gracilaria cornea J. Agardh is an important agarophyte occurring in the western Atlantic Ocean. Green colour individuals of G. cornea were found in a natural population, growing next to red individuals, which were more common. Due to the importance of colour strains in genetic and intraspecific variability studies, this work aimed to characterize the red and green strains evaluating different nutritional and light conditions. Red and green gametophytes were cultivated at 14:10 light: dark cycle, with alternating aeration periods of 30 min. Two different enriched solutions were tested: von Stosch (VSS) at concentrations reduced to 12.5% and 25%; and Provasoli (PES) at concentrations reduced to 25% and 50%, and 100%. Red and green gametophytes were cultivated at the irradiance of 45 mumol photons m-2 s-1. In another experiment utilizing PES 100%, two sources of light (Osram 40 W daylight fluorescent tubes and Sylvania Designer 3,500 tubes) were tested at irradiances of 90 and 180 mumol photons m-2 s-1. Growth rates (GR) were evaluated for five weeks. Gametophytes developed few branches and reproductive structures were not induced. Differences were not observed between GR of red and green strains in the conditions tested. GR were higher in VSS 12.5% (8.4% day-1) than in 25% (7.1% day-1), suggesting an adaptation of the species to low nutrient concentrations. GR were higher at 180 (9.0% day-1) than at 90 mumol photons m-2 s-1 (6.3% day-1). These results suggest that G. cornea should be cultivated in laboratory at high irradiances and low nutrient concentrations. These data will be useful in future genetic and physiological studies of the species.

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Green algal species and their association with physicochemical parameters in some manmade ponds in Zaria, Nigeria were studied from November 2005 to August 2006. Phytoplankton and water samples were collected, preserved and analyzed using standard methods. A total of 27 green algal species divided into 16 families were recorded. Shannon diversity indices ranged from 1.75 to 2.39 in all ponds, dominance index from 0.14 to 0.23 and species evenness 0.56 to 0.64. Closterium sp. and Rhizoclonium hookeri Kuetz. were positively associated with the concentration of Fe, however they were negatively correlated (sensitive) to alkalinity, total dissolved solids and electrical conductivity. Stichococcus bacillaris Naegeli, Staurastrum rotula Nordst. and Sphaeroplea sp. had significant positive relationship with biochemical oxygen demand (BOD), Mn, and Mo levels in the water. Pseudouvella americana (Snow) Wille. and Scenedesmus quadricauda (Turp.) de Bréb. showed a close positive association with alkalinity but were sensitive to Fe, BOD, Mn and Mo. The species reported here showed closed association with physicochemical factors in these ponds.

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G protein-coupled receptor (GPCR) activation is followed rapidly by adaptive changes that serve to diminish the responsiveness of a cell to further stimulation. This process, termed desensitization, is the consequence of receptor phosphorylation, arrestin binding, sequestration and down-regulation. GPCR phosphorylation is initiated within seconds to minutes of receptor activation and is mediated by both second messenger-dependent protein kinases and receptor-specific G protein-coupled receptor kinases (GRKs). Desensitization in response to GRK-mediated phosphorylation involves the binding of arrestin proteins that serve to sterically uncouple the receptor from its G protein. GPCR sequestration, the endocytosis of receptors to endosomes, not only contributes to the temporal desensitization of GPCRs, but plays a critical role in GPCR resensitization. GPCR down-regulation, a loss of the total cellular complement of receptors, is the consequence of both increased lysosomal degradation and decreased mRNA synthesis of GPCRs. While each of these agonist-mediated desensitization processes are initiated within a temporally dissociable time frame, recent data suggest that they are intimately related to one another. The use of green fluorescent protein from the jellyfish Aqueora victoria as an epitope tag with intrinsic fluorescence has facilitated our understanding of the relative relationship between GRK phosphorylation, arrestin binding, receptor sequestration and down-regulation.

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We report the antinociceptive activity, determined by the writhing, formalin and hot-plate tests in mice, of crude (F0/60), lectin and carbohydrate fractions isolated by ammonium sulfate precipitation (0 to 60%) from Bryothamnion seaforthii and B. triquetrum, species of red algae. Not only fraction F0/60 but also lectins from both species significantly inhibited acetic acid-induced abdominal contractions after intraperitoneal or oral administrations. In the formalin test, lectins (1 and 5 mg/kg, ip, and 5 to 20 mg/kg, po) inhibited the 1st and 2nd phases (5 and 20 min, respectively), but the effect occurred predominantly on the 2nd phase. The effects of the lectins were totally or partially reversed by naloxone (2 mg/kg, sc) in the 1st and 2nd phases, respectively. Experiments performed with lectins in the absence and presence of avidin (1 mg/kg, ip) and D-mannose (1 mg/kg, ip) showed that avidin did not interfere with the effect of B. seaforthii lectin but partially reversed the effect of B. triquetrum lectin. D-Mannose completely reversed the effects of both species. F0/60 fractions from both algae significantly increased the latency time in response to thermal stimuli, and naloxone reversed antinociception, indicating the involvement of the opioid system in both the peripheral and central effects of the fractions. In the writhing test, the carbohydrate fractions were the most active, inhibiting the contractions by 71 and 79% (B. triquetrum) and by 46 and 69% (B. seaforthii) at doses of 1 and 5 mg/kg, ip, respectively. Sulfated carbohydrate fractions of B. seaforthii and B. triquetrum, containing only about 5% protein as contaminants, are probably responsible for the antinociceptive effects of these red algae.

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The objective of the present study was to examine the effect of green tea polyphenols (GTPs) supplementation during in vitro maturation, in vitro fertilization, and in vitro culture on the developmental competence of bovine oocytes. Cumulus-oocyte complexes aspirated from the ovaries were matured in vitro (38.5ºC for 24 h) and fertilized (38.5ºC for 15-18 h) and embryos were cultured (38.5ºC for 192 h) in a defined conditioned medium with or without GTPs supplementation. The GTPs used in the present study contained 99% catechin derivatives, with the major components being 50% (-)-epigallocatechin gallate, 22% (-)-epicatechin gallate, 18% (-)-epigallocatechin, and 10% (-)-epicatechin. Four replicate trials were done for each type of experiment. GTPs supplementation (15 µM) of the maturation medium led to a significant increase in the rate of blastocyst formation (34.0 vs 21.4%, P < 0.05). However, the rate of blastocyst formation was not improved when higher GTPs concentrations (20 or 25 µM) were added to the in vitro maturation medium. During in vitro fertilization, supplementation with higher GTPs concentrations (20 or 25 µM) significantly reduced the rate of blastocyst formation (P < 0.05). Supplementation of the culture medium with 15 µM GTPs improved the rate of blastocyst formation, while higher GTPs concentrations (25 µM) significantly reduced embryo development (P < 0.05). In conclusion, these results demonstrate that supplementation with GTPs at low concentration (15 µM) during in vitro maturation and in vitro culture improved the developmental competence of bovine oocytes.

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Ochratoxin A is a nephrotoxic, teratogenic and imunotoxic compound produced by Aspergillus and Penicillium spp. It is a suspected carcinogen to humans and it is carcinogenic to rats. Recently it has drawn attention because it has been found in coffee and it has been the object of regulation by coffee importing countries. Brazil is the largest coffee producing country and its largest consumer. In order to conduct an initial assessment of the situation of the coffee produced in the country and offered to its population, one hundred and thirty two samples of Brazilian green coffee from 5 producing states (Minas Gerais, Paraná, São Paulo, Espírito Santo and Bahia) and destined for the home market, were collected at sales points at the cities of Londrina and Santos, Brazil, and analyzed for ochratoxin A. The toxin was isolated in immunoaffinity columns and quantified by HPLC with florescence detection. The limit of detection was 0.7ng/g and the average RSD for duplicates of the samples was 11%. Twenty seven samples were found contaminated with the toxin and the average concentration for the contaminated samples was 7.1ng/g ochratoxin A. Neither the total number of defects nor the number of specific defects according to the Brazilian coffee classification system (black, partly -- black, sour, stinkers-black, stinkers-green, pod beans) showed any relation to the contamination of the samples with ochratoxin A.

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The presence of ochratoxin A (OTA) in foods has led some countries to establish regulatory limits. Although coffee is not a major source of OTA in human consumption, the European Community (EC) may establish limits in the near future, with possible economic impact on producing countries. This study measured the OTA content with HPLC in 37 samples of Brazilian green coffee exclusive destined to the export market and also verified a possible relation between coffee defects and OTA content. The results showed an OTA concentration ranging from < 0.16ng/g (detection limit) to 6.24ng/g (average of 3.20ng/g) for 37 samples. Of the five samples observed for defects, toxin content of sound beans ranged from 0.22 to 0.80ng/g (average 0.46ng/g) and of defective beans from 0.42 to 17.46 (average 4.52ng/g). Morphological differences among sound and defective beans showed no susceptibility for mould invasion under optical microscopy observation. One black bean depicted the presence of mould and spores on observation under Scanning Electron Microscope (SEM). According to this investigation, Brazilian green coffee for export complies with most limits in place.

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The postharvest losses of horticultural products justify the use of preservation techniques. The processing not only adds value to the products, but also makes the products more convenient to the consumers. The objective of this research was to define the methodologies for the minimal processing of carrot and green pepper as to the type and intensity of the adoption of conservation techniques, and to monitor the products after processing through microbiological, physicochemical and nutritional analysis. The vegetables were washed and they were immersed in cold (7ºC) water with 100 mg L-1 free chlorine for sanitation, followed by centrifugation for 5 min. The product was put into BOPP/LDPE (biaxially orientated polypropylene/low-density polyethylene) plastic bags, which were sealed under atmospheric air, vacuum and modified atmosphere (2% O2, 10% CO2, 88% N2) and stored at 1ºC±1ºC. The approximate composition of the vegetables stayed stable during the storage period, in the three tested treatments. The contents of vitamin C for the samples of minimally processed carrot and green pepper did not present differences among treatments. The contents of beta-carotene decreased slightly during the storage period for the minimally processed carrot and green pepper. After processing, carrot and green pepper had psychrotrophic counts of 10²-10(5) and 10³-10(6) CFU g-1, respectively. Anaerobic mesophiles and total coliforms were found in green peppers, representing 1.6x10³ - 7.4x10(5) and <10.g-1 - 7.4x10(5), respectively. Total and fecal coliforms, anaerobic mesophiles and Salmonella were not found in carrots. Salmonella was not found in green pepper.