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Search Results: 1 - 10 of 467450 matches for " Júlio César Lima;Fontes "
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Nodula??o, fixa??o de nitrogênio e produ??o de matéria seca de alfafa em resposta a doses de calcário, com diferentes rela??es cálcio:magnésio
Gomes, Fernando Teixeira;Borges, Arnaldo Chaer;Neves, Júlio César Lima;Fontes, Paulo Cezar Rezende;
Ciência Rural , 2002, DOI: 10.1590/S0103-84782002000600003
Abstract: high aluminum concentrations decrease the nodulation potential, hence the biological atmosferic nitrogen fixation of legume. this greenhouse experiment was aimed to evaluate the effects of limestone applyet on alfalfa cultivation in alic yellowish red latosol soil, clay texture. it evaluated the ideal ca2+ and mg2+ ratios in neutralizing soil acidity. treatments were two alfalfa cultivars (florida 77 and creoula), four limestone rates (1.2; 2.4; 4.8; 7.2t.ha-1) and five stoichiometric percentual ratios ca:mg between (100:0; 75:25; 50:50; 25:75; 0:100), in a factorial set up into a completely randomized design with four replications. nodulation and nitrogen contents in the shoots increased with increased limestone rates. shoots dry matter production of both cultivars increased with the rates of limestone, but only the cultivar florida 77 showed significant differences among ca:mg ratios.
Influência de doses de calcário com diferentes rela??es cálcio: magnésio na produ??o de matéria seca e na composi??o mineral da alfafa
Gomes, Fernando Teixeira;Borges, Arnaldo Chaer;Neves, Júlio César Lima;Fontes, Paulo Cezar Rezende;
Pesquisa Agropecuária Brasileira , 2002, DOI: 10.1590/S0100-204X2002001200015
Abstract: acidic brazilian soils presenting toxic aluminum levels, plus low essential elements availability, specially phosphorus, demand limestone and fertilizers application for adequate agricultural use. the effect of four limestone rates, based on soil al3+ concentrations and five ca:mg ratios on the shoot dry matter yield and mineral composition of two alfalfa cultivars (florida 77 and crioula), cultivated in an alic red-yellow latosol, clayish texture was evaluated, under greenhouse conditions. a factorial scheme in a completely randomized design with four repetitions was used. the shoot dry matter yield of both cultivars increased with the rates of limestone, but only the cultivar florida 77 showed significant differences among ca:mg ratios. concentrations of ca, mg and n in the shoots dry matter, in general, increased in response to applied limestone, but only the ca and mg altered by the different ca:mg ratios. values for p and k, showed small decreases with the increase in limestone rates, although still satisfactory for alfalfa nutrition.
Influência de doses de calcário com diferentes rela es cálcio: magnésio na produ o de matéria seca e na composi o mineral da alfafa
Gomes Fernando Teixeira,Borges Arnaldo Chaer,Neves Júlio César Lima,Fontes Paulo Cezar Rezende
Pesquisa Agropecuária Brasileira , 2002,
Abstract: A acidez dos solos brasileiros, com alumínio em níveis tóxicos e baixa disponibilidade de elementos essenciais, principalmente o fósforo, exige aplica es de calcário e fertilizantes para a adequada utiliza o agrícola. Este trabalho objetivou avaliar o efeito de quatro doses de calcário calculadas com base no teor de Al3+ trocável do solo e em cinco rela es molares de Ca:Mg, na produ o de matéria seca e na composi o mineral da alfafa. Duas cultivares de alfafa, Flórida 77 e Crioula, foram cultivadas em Latossolo Vermelho-Amarelo álico, textura argilosa, em casa de vegeta o, em esquema fatorial disposto no delineamento inteiramente casualizado, com quatro repeti es. A produ o de matéria seca da parte aérea das duas cultivares aumentou em raz o do aumento das doses de calcário, e somente a cultivar Flórida 77 apresentou diferen as significativas entre as rela es molares Ca:Mg. Os teores de Ca, Mg e N na matéria seca da parte aérea, de modo geral, aumentaram em raz o do aumento na quantidade de calcário, sendo somente os teores de Ca e Mg alterados pelas diferentes rela es molares de Ca:Mg. Os teores de P e K, de modo geral, apresentaram pequenos decréscimos com a eleva o das doses de calcário, embora considerados satisfatórios para a nutri o da alfafa.
Nodula o, fixa o de nitrogênio e produ o de matéria seca de alfafa em resposta a doses de calcário, com diferentes rela es cálcio:magnésio
Gomes Fernando Teixeira,Borges Arnaldo Chaer,Neves Júlio César Lima,Fontes Paulo Cezar Rezende
Ciência Rural , 2002,
Abstract: Altas concentra es de alumínio reduzem a eficência da nodula o e da fixa o biológica do nitrogênio atmosférico em leguminosas. O presente ensaio foi realizado em casa de vegeta o com o objetivo de avaliar a necessidade de calagem para o cultivo da alfafa em LATOSSOLO VERMELHO-AMARELO álico, textura argilosa. Também foi avaliado o efeito da rela o Ca:Mg do calcário aplicado ao solo, sobre a nodula o, os teores de nitrogênio e a produ o de matéria seca da parte aérea. Os tratamentos consistiram de duas cultivares de alfafa (Flórida 77 e Crioula), quatro doses de calcário (1,2; 2,4; 4,8; 7,2 t ha-1) e cinco rela es percentuais estequiométricas entre Ca e Mg (100:0; 75:25; 50:50; 25:75; 0:100), em delineamento fatorial inteiramente casualizado, com quatro repeti es. A nodula o e os teores de nitrogênio na parte aérea aumentaram com a adi o de doses crescentes de calcário ao solo. A produ o de matéria seca da parte aérea das duas cultivares aumentou em fun o do aumento das doses de calcário, sendo que somente o cultivar Flórida 77 apresentou diferen as significativas entre as rela es Ca:Mg. A rela o 100:0 foi a que rendeu maior produ o de matéria seca da parte aérea.
Desenvolvimento de mudas de cedro-rosa em solo contaminado com cobre: tolerancia e potencial para fins de fitoestabiliza??o do solo
Caires, Sandro Marcelo de;Fontes, Maurício Paulo Ferreira;Fernandes, Raphael Bragan?a Alves;Neves, Júlio César Lima;Fontes, Renildes Lúcio Ferreira;
Revista árvore , 2011, DOI: 10.1590/S0100-67622011000700004
Abstract: agricultural, industrial and mining activities are the mainly factors related to soil contamination, as well the reuse of urban and/or animal residues. these activities can produce heavy metals accumulation in soils, which are potentially dangerous chemical elements to environmental quality and to well-being of living beings. phytoremediation is a technology for rehabilitation of degraded areas which aims the soil decontamination. forest species can immobilize and export to outside of the system larger amounts of chemical elements from contaminated soil, because they have high biomass production. the objective of this study was to evaluate the cedrela fissilis development in contaminated soil by heavy metals. with this propose, seedlings were cultivated in greenhouse and in a contaminated soil by cu (0, 60, 80, 100, 500 mg kg-1) for 105 days. after this period some soil and plant parameters were evaluated. seedlings of c. fissilis presented crescent increments of dry matter until 100 mg kg-1 of cu, with reduction of vegetal development in the high doses. in general, it was verified high partition of dry matter to root system than aerial part. plant cu contents were correlated with applied doses in the soil. the root bioconcentraction factor of c. fissilis indicates potential capacity of this tree specie to phytostabilization works in contaminated soils.
Rice grown in nutrient solution with doses of manganese and silicon
Zan?o Júnior, Luiz Ant?nio;Fontes, Renildes Lúcio Ferreira;Neves, Júlio César Lima;Kornd?rfer, Gaspar Henrique;ávila, Vinícius Tavares de;
Revista Brasileira de Ciência do Solo , 2010, DOI: 10.1590/S0100-06832010000500016
Abstract: although silicon is not recognized as a nutrient, it may benefit rice plants and may alleviate the mn toxicity in some plant species. the dry matter yield (root, leaf, sheaths and leaf blade) and plant architecture (angle of leaf insertion and leaf arc) were evaluated in rice plants grown in nutrient solutions with three mn doses, with and without si addition. the treatments were arranged in a 2 x 3 factorial [with and without (2 mmol l-1) si; three mn doses (0.5; 2.5 and 10 μmol l-1)], in a randomized block design with 4 replications. the experimental unit was a 4 l plastic vase with 4 rice (metica-1 cultivar) plants. thirty nine days after keeping the seedlings in the nutrient solution the plant dry matter yield was determined; the angle of leaf insertion in the sheath and the leaf arc were measured; and the si and mn concentrations in roots, sheaths and leaves were determined. the analysis of variance (f test at 5 and 1 % levels) and the regression analysis (for testing plant response to mn with the si treatments) were performed. the si added to the nutrient solution increased the dry matter yield of roots, sheaths and leaf blades and also decreased the angle of leaf blade insertion into the sheath and the foliar arc in the rice plant. additionally, it ameliorated the rice plant architecture which allowed an increase in the dry matter yield. similarly, the addition of mn to the solution improved the architecture of the rice plants with gain in dry matter yield. as si was added to the nutrient solution, the concentration of mn in leaves decreased and in roots increased thus alleviating the toxic effects of mn on the plants.
Dose de nitrogênio associada à produtividade de batata e índices do estado de nitrogênio na folha
Coelho, Fabrício Silva;Fontes, Paulo Cezar Rezende;Puiatti, Mário;Neves, Júlio César Lima;Silva, Marcelo Cleón de Castro;
Revista Brasileira de Ciência do Solo , 2010, DOI: 10.1590/S0100-06832010000400017
Abstract: nitrogen has strong impact on potato yield and its effects on plants can be evaluated by specific nutritional diagnostic techniques. the objective of this work was to determine the optimum economical n rate for tuber yield and to estimate the critical value of plant n indices in leaf of two potatoes cultivars. the experiment had a 4x2 factorial in a completely randomized block design with four replications, with four n levels (0, 100, 200 e 400 kg ha-1 of n, pre-planting applied as urea) and two potato cultivars (ágata e asterix), from april to june 2008. spad reading values, nitrogen and chlorophyll contents were determined in the fourth leaf from the apex 21 days after plant emergence. marketable tuber yield of ágata and asterix increased up to 45,065 e 46,500 kg ha-1 as n rates increased up to 297 and 250 kg ha-1 for agata and asterix, respectively. the maximum economic efficiency rate of these cultivars was 290 and 245 kg ha-1 of n, respectively. for both cultivars, the n effect on spad values, nitrogen and chlorophyll contents were positive and significant. critical values were 40.5 and 43.7 for spad readings, 66.7 and 75.2 g kg-1 for leaf n concentration, and 6.13 and 6.96 mg g-1 for total leaf chlorophyll contents, respectively, for agata and asterix. the spad reading values correlated with the values of extractable total chlorophyll in the fourth leaf and potato tuber yields at the final harvest, indicating the possibility of using spad measurement at 21 days after plant emergence to prognostic final potato tuber yield.
A educa o para além do capital
Júlio César Fran?a Lima
Trabalho, Educa??o e Saúde , 2006, DOI: 10.1590/s1981-77462006000100014
Abstract:
Os cientistas brasileiros visitam a Amaz?nia: as viagens científicas de Oswaldo Cruz e Carlos Chagas (1910-1913)
Schweickardt, Júlio César;Lima, Nísia Trindade;
História, Ciências, Saúde-Manguinhos , 2007, DOI: 10.1590/S0104-59702007000500002
Abstract: the article analyzes reports from two scientific journeys into the amazon conducted by the instituto oswaldo cruz, in 1910 and 1913, under the leadership of oswaldo cruz and carlos chagas, respectively. these reports contributed to the construction of representations and images of the region. field observations not only provided data for the study and control of tropical diseases but also had a hand in the movement to denounce the serious sanitation conditions under which rubber workers labored. journeys through the amazon valley put the scientists in direct contact with the environment and with sick populations; these travels also made them face the huge challenges of learning about malaria and trying to control it. analyses of these reports are part of studies on 'portraits of brazil', which raise issues within the history of public health policies. in this endeavor to reveal the process by which scientific records are constructed, we worked with primary sources, from manuscripts to official texts.
Do "inferno florido" à esperan?a do saneamento: ciência, natureza e saúde no estado do Amazonas durante a Primeira República (1890-1930)
Schweickardt, Júlio César;Lima, Nísia Trindade;
Boletim do Museu Paraense Emílio Goeldi. Ciências Humanas , 2010, DOI: 10.1590/S1981-81222010000200012
Abstract: in the first two decades of the 20th century, publications of euclides da cunha, alberto rangel and carlos chagas about the amazon presented from different perspectives a critique of what they considered unrealistic visions originated in the travel accounts of naturalists of 18th and 19th centuries. alternatively, they proposed the analysis of the region from the perspective of new scientific knowledge, which included several areas - from geology to tropical medicine. recent studies have indicated the need for more research on the institutions and local scientific practices, both in the development of ideas about the region and the definition of public policies. this article is proposed on this perspective, to reflect on the different ideas that were built by the medical-scientific thought about nature and society in the state of amazonas during the brazilian first republic, when the rise and decline of the amazonian rubber was experienced. it is understood that local physicians actively participated in scientific discussions related to tropical medicine, and put into practice the main theses about control and prevention of endemic diseases like malaria and yellow fever. this set of ideas and practices contributed to the definition of sanitation of the city of manaus and the hinterland of state of amazonas.
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