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Search Results: 1 - 10 of 22412 matches for " Ivan Caldeira Almeida Alvarenga "
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Gas Exchange and Production of Photosynthetic Pigments of Piper aduncum L. Grown at Different Irradiances  [PDF]
Fernanda Ventorim Pacheco, Helbert Rezende de Oliveira Silveira, Amauri Alves Alvarenga, Ivan Caldeira Almeida Alvarenga, José Eduardo Brasil Pereira Pinto, Jean Marcel Sousa Lira
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.412A3014
Abstract:

The species Piper aduncum is a plant with great economic potential, because the essential oil has antimicrobial activity and insecticides. Thus, as the light directly affects photosynthesis process, the present study evaluated the gas exchanges variables and photosynthetic pigments production of P. aduncum grown under different irradiances. Treatments consisted in environments with 100%, 70% and 50% of irradiance and environments with colored nets (red and blue). After 150 days of culture, photosynthetic activity (A), stomatal conductance (gs) transpiration rate (E), internal CO2 concentration (Ci), deficit vapor pressure (DVP), leaf temperature, concentration of internal/external CO2 (Ci/Ca), carboxylation efficiency (A/Ci) and efficiency water use (A/E) were evaluated. Pigments chlorophyll a, b, carotenoids, total and chlorophyll a

Optimization of the Protocol for the in Vitro Cultivation of Piper aduncum L.  [PDF]
Samia Torres Silva, Fernanda Ventorim Pacheco, Ivan Caldeira Almeida Alvarenga, José Eduardo Brasil Pereira Pinto, Suzan Kelly Vilela Bertolucci, Cibelly Pereira Ferreira
American Journal of Plant Sciences (AJPS) , 2014, DOI: 10.4236/ajps.2014.523363
Abstract:
Piper aduncum L. (Piperaceae) has great potential for economic exploration because of the proven use of its essential oil in the agriculture and in the human health. A technique that improves its propagation, as the tissue culture, becomes necessary. Some parameters must be determined for the successful cultivation in vitro. Thus, this study aimed to determine the salts concentration of MS medium, temperature, luminosity and light quality for in vitro culture of this species. The following treatments were conducted: 1/4MS, 1/2MS, MS and 2MS; 20, 25, 30 and 35; monochromatic blue, red and white lights and the combination of red and blue, using light emitting diodes (LEDs); luminosities of 17, 37, 48 and 73 μmol·m-2·s-1 obtained with cool white fluorescent lamp. After 35 days, the treatments were analyzed. To determine the salts concentration of MS, the variables were evaluated: number of shoots, leaves and roots, length and width of leaves, length and dry mass of root and shoots and percentage of death by necrosis. To the plantlets under different temperatures, length and dry mass of shoot and root, number of shoots, number, length and width of leaves and survival and rooting percentages were measured. The plantlets that were maintained under different luminosities were evaluated for length of shoot and root, dry mass of leaf and root. To evaluate the growth under the LEDs, the length and dry mass of shoot and root, number of shoots and roots, percentage of rooting and sprouting were assessed. The medium 1/4MS and the medium 1/2MS showed better responses for number and length of root, leaf width and shoot length. The temperature 25 provided the highest number of leaves, length of shoot and root, root dry mass and rooting percentage. The luminosity 73 μmol·m-2·s-1 provided higher values in length of root and dry mass of leaf and root. The red LED provided plantlets with greater growth. Thus, for the in vitro cultivation of Piper aduncum, 1/4MS, environment temperature of 25, light intensity of 73
Fator de resposta do alecrim-pimenta a diferentes laminas de irriga??o
Alvarenga, Ivan Caldeira Almeida;Lopes, Otávio Diniz;Pacheco, Fernanda Ventorim;Oliveira, Flávio Gon?alves;Martins, Ernane Ronie;
Pesquisa Agropecuária Tropical , 2012, DOI: 10.1590/S1983-40632012000400006
Abstract: evaluating the response of medicinal plants to irrigation is not very common, especially when they are native species with economic potential, such as the lippia sidoides. thus, this study aimed at evaluating the lippia sidoides response, by using the ky coefficient, and growth, under different irrigation depths. the coefficients were determined from the dry matter and essential oil yields. the experiment used a randomized blocks design, with treatments consisting of seven irrigation depths (0.5, 0.75, 1.0, 1.2, 1.4, 1.65 and 1.9 of the eto), with three replications. the eto was evaluated by using the penman-monteith method and the etr according to the soil water balance. growth was determined by measuring the stem diameter and height, at 35, 56, 77, 98 and 119 days after transplanting. at 120 days of cultivation, samples were collected to determine the dry matter and essential oil yields. the plant responded to water deficit with coefficients above 1.0, for both dry matter and essential oil yields. growth was positively affected by irrigation, reaching higher values for stem diameter and height when the highest irrigation depths were used.
Water stress before harvest of pepper-rosmarin
Alvarenga, Ivan Caldeira Almeida;Valadares, Rafael Vasconcelos;Martins, Ernane Ronie;Oliveira, Flávio Gon?alves;Figueiredo, Lourdes Silva de;Kobayashi, Mauro Koji;
Pesquisa Agropecuária Brasileira , 2011, DOI: 10.1590/S0100-204X2011000700005
Abstract: the objective of this work was to assess the effect of different periods of water stress before harvest of pepper-rosmarin (lippia sidoides) on the contents of essential oil and flavonoids. the experiment was carried out during 270 days of cultivation, with drainage lysimeters, in a completely randomized block design with five treatments: 0, 2, 4, 6, and 8 days of water suppression before harvest, with four replicates. fresh and dry matter yield, essential oil content, total flavonoids content, and water potential and temperature of leaves were determined. there was a decrease of approximately 50% in oil content and of 60% in total flavonoid content with the reduction of leaf water potential in 0.3 mpa. essential oil is more sensitive to water stress than total flavonoids.
Qualidade de vida em pacientes pediátricos com dermatite atópica
Alvarenga, Tassiana M. M.;Caldeira, Ant?nio P.;
Jornal de Pediatria , 2009, DOI: 10.1590/S0021-75572009000500008
Abstract: objective: to measure the impact of atopic dermatitis (ad) on the quality of life of pediatric patients and their families, establishing correlations with scores of disease severity. methods: this was an observational study of the correlations between clinical indicators of severity and two questionnaires on quality of life: idqol and dfi. the study also included scoring of eczema severity - easi. forty-two children with ad, fulfilling established diagnostic criteria, and 44 children with other dermatologic diseases were investigated for the effect of eczema on quality of life. pearson's correlation was used for the correlation analysis and the comparison between the groups was carried out using the mann-whitney test. results: data analysis demonstrated significant differences between the scores for the two groups. the mean score in the eczema group was 9.2 (range 1-19) for idqol and 8.5 (range 0-17) for dfi. the highest scoring questions for idqol referred to itching and scratching, mood changes and problems caused by treatment. for the fdi, the highest impact domains were treatment-related expenditure and sleep disturbance affecting family members. conclusions: ad has a negative impact on the quality of life of pediatric patients and their families. data obtained in studies of quality of life in ad should be used to guide clinical practice in order to identify individual treatment strategies and should lead to the adoption of measures to reduce the impact of the disease on patients and their families.
Novas referências de hepáticas (Marchantiophyta) da Floresta Nacional de Caxiuan? para o Estado do Pará, Brasil
Alvarenga, Lisi Dámaris Pereira;Lisboa, Regina Célia Lobato;Tavares, Ana Cláudia Caldeira;
Acta Botanica Brasilica , 2007, DOI: 10.1590/S0102-33062007000300012
Abstract: eight new records of liverwort species for pará state are reported; five of these are also new records for northern brazil. these species come from the ferreira penna scientific station (1o42'30"s; 51o31'45"w) located in caxiuan? national forest (eastern amazonia). they are ceratolejeunea desciscens (sande-lac.) schiffn., colura greig-smittii jovet-ast, lejeunea raddiana lindenb. gottsche, rectolejeunea emarginuliflora (gottsche) a. evans, arachniopsis monodactyla (spruce) r.m. schust., plagiochila aerea tayl., plagiochila gymnocalycina (lehm. & lindenb.) lindenb. and plagiochila martiana (nees) lindenb. relevant taxonomic comments are included as well as species illustrations.
Exchanging carrion for fresh meat: the vulture Cathartes burrovianus (Aves, Cathartidae) preys on the snake Xenodon merremii (Serpentes, Dipsadidae) in southeastern Brazil
Thiago Oliveira e Almeida,Fernanda Carvalho Machado,Henrique Caldeira Costa
Biotemas , 2010,
Abstract: The Lesser Yellow-headed Vulture (Cathartes burrovianus) is known mainly for its necrophagic habits, typical of the Cathartidae. However, members of this family also hunt live prey, though this behavior is not well documented. We report here on a C. burrovianus preying on the non-venomous snake Xenodon merremii, at an anthropogenic site in southeastern Brazil.
Phytoplasma associated with shoot proliferation in begonia
Ribeiro, Luiz Fernando Caldeira;Mello, Ana Paula de Oliveira Amaral;Bedendo, Ivan Paulo;Gioria, Ricardo;
Scientia Agricola , 2006, DOI: 10.1590/S0103-90162006000500009
Abstract: begonia is a very appreciated genus of ornamental plants, of economic relevancy, having species of flowers and foliage. in commercial croppings, plants exhibiting characteristic symptoms of phytoplasma infection have been observed, such as shoot proliferation, reduced plant, size small leaves and flowers, and phyllody. leaves were sampled and total dna was extracted to be used in nested polymerase chain reaction (pcr), in order to detect and identify an expected phytoplasma. the results confirmed consistently the presence of a phytoplasma associated with symptomatic plants through the amplification of a typical genomic fragment of 1.2 kb by using the universal primers r16mf2/mr1 and r16f2n/r2. the use of specific primers r16(iii)f2/r1 allowed to identify the phytoplasma detected as a representative of the group 16sriii. this information is very expressive, because different diseases caused by fungus, bacteria, virus and nematodes have been reported for begonia, however, reports have not been found for begonia diseases associated with phytoplasmas.
Evidência molecular da ocorrência de um fitoplasma associado ao lenho mole da macieira
Ribeiro, Luiz Fernando Caldeira;Bedendo, Ivan Paulo;Sanhueza, Rosa Maria Valdebenito;
Summa Phytopathologica , 2007, DOI: 10.1590/S0100-54052007000100004
Abstract: apple rubbery wood is an important disease occurring worldwide. typical symptoms have been observed since 80' decade in orchards located in the south part of brazil. in previous studies, grafting has evidenciated that the disease had infeccious etiology and visualization of filamentous bodies inside phloem had indicated that a phytoplasma could be associated with the disease. in the present study, plants with symptoms of rubbery wood were sampled in a commercial orchard in order to demonstrate the presence of phytoplasma in infected tissue and to identify molecularly that the organism. using nested pcr with universal primers pairs r16mf2/r1 and r16f2n/r2, phytoplasma was consistently detected in symptomatic plants. identification conducted with specific primer pair r16(iii)f2/r1 in nested pcr demonstrated that the phytoplasma was a member of group 16sriii. rflp analyses with endonucleases alui, kpni, hinfi, hpaii, msei, rsai e sauiiia confirmed that the phytoplasma was a representative of the group 16sriii. the detection and molecular identification are strong evidences that a phytoplasma is associated with apple rubbery wood in brazil and agrees with previous evidences using grafting and electron microscopy.
Phytoplasma associated with shoot proliferation in begonia
Ribeiro Luiz Fernando Caldeira,Mello Ana Paula de Oliveira Amaral,Bedendo Ivan Paulo,Gioria Ricardo
Scientia Agricola , 2006,
Abstract: Begonia is a very appreciated genus of ornamental plants, of economic relevancy, having species of flowers and foliage. In commercial croppings, plants exhibiting characteristic symptoms of phytoplasma infection have been observed, such as shoot proliferation, reduced plant, size small leaves and flowers, and phyllody. Leaves were sampled and total DNA was extracted to be used in nested Polymerase Chain Reaction (PCR), in order to detect and identify an expected phytoplasma. The results confirmed consistently the presence of a phytoplasma associated with symptomatic plants through the amplification of a typical genomic fragment of 1.2 kb by using the universal primers R16mF2/mR1 and R16F2n/R2. The use of specific primers R16(III)F2/R1 allowed to identify the phytoplasma detected as a representative of the group 16SrIII. This information is very expressive, because different diseases caused by fungus, bacteria, virus and nematodes have been reported for begonia, however, reports have not been found for begonia diseases associated with phytoplasmas.
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