Multiplicidade e concentração de soluções positivas para uma equação elíptica quasilinear

Neste trabalho, estudamos resultados de existência e concentração de soluções positivas de uma equação de Schrödinger em RN envolvendo o operador p-laplaciano com 2 &#8804; p < N , uma não-linearidade do tipo potência com expoente q subcrítico, um parâmetro &#654; positivo e um potencial a(x) satisfazendo certas hipóteses. Tal problema foi inicialmente estudado por Bartsch e Wang em [5] no caso do operador laplaciano ( p = 2). Apresentamos as versões dos resultados de [5] para o caso do p-laplaciano, demonstradas por Furtado em [17, 18]

Caracterização dos solos do município de Belterra, Estado do Pará.

bitstream/item/63490/1/Oriental-Doc88.pdfAnexo mapa: Mapa de solos do Município de Belterra - Pará

Métodos químicos para extração de boro no solo.

bitstream/item/71813/1/ID-30969.pd

Do plant species influence soil gas fluxes in tropical forests?

Abstract ID: 53. Publicado também on-line

Effect of glyphosate on nodule formation and its interrelation with nickel content in glyphosate-resistant soybeans.

Recent research has demonstrated that glyphosate can decrease biological nitrogen fixation in glyphosate-resistant (GR) soybeans, however this reduction has been attributed directly to the effect of glyphosate on the microorganisms or indirectly through its intermediates that are also toxic to these microorganisms. This work aims to demonstrate that glyphosate can influence the symbiotic N2 fixation by lowering nickel content available to the microorganisms. The experiment was conducted in the greenhouse at the State University of Maringá, PR, Brazil during the summer cropping season, 2008. The experimental design was a completely randomized blocks in a factorial scheme 4 x 3 x 2 where the first factor was: (T1 - single application of glyphosate (900 g a.e. ha-1) at the four-leaf stage; T2 - sequential application (450 + 450 g a.e. ha-1) at the four-leaf and five-leaf stage; T3 - without glyphosate; T4 - non-GR parental line]; the second factor, maturity group (early, medium and late;) and third factor soil type. Under glyphosate use, GR soybeans showed reduced photosynthetic parameters, nickel contents, and nodule, shoot and root dry biomass

Effect of increasing doses of glyphosate on water use efficiency and photosynthesis in glyphosate-resistant soybeans.

The increase cultivated area of GR soybeans across different regions of the world have raised questions not yet answered as related secondary effects of glyphosate on physiology of GR soybeans. In this work, we attempted to measure the effect of increasing glyphosate doses on water absorption and photosynthetic parameters of soybean, cv. BRS 242 GR. Plants were grown in completed nutrient solution (Hoagland & Arnon, 1950) in a greenhouse equipped with an evaporative cooling system (25?35 : 20?22C day/night) under natural daylight. The commercially formulated isopropylamine salts of glyphosate was sprayed on foliar doses of 450, 675, 900, 1350 and 1800 g. e.a ha-1 either in single application at four leaf stage (24 DAE) and in sequential application (24 and 36 DAE) (50%-50%) at four and five leaf stages, respectively. Using an infrared gas analyzer (IRGA), fluorometer (pulse-modulated) and chlorophylometer, before and after herbicide application net photosynthesis (A), transpiration rate (E), stomatal conductance (gs), sub-stomatal CO2 (Ci), carboxilation efficiency (A/Ci), fluorescence (Fs), maximal fluorescence (Fms); yield of quantum efficiency (Y=Fm-Fs/Fms) and chlorophyll contents were monitored. In addition, water absorption was measured daily and biomass yield and water use efficiency (WUE) were estimated by harvesting plants at R1 stage. All measures of photosynthetic parameters (A, E, gs, Ci) and Fs, Fms and Y were affected by increasing glyphosate doses. Chlorophyll contents were reduced right after glyphosate use, however with decreased in chlorophyll content and carboxilation efficiency, (A/Ci) the values suggest that glyphosate might have interfering, in some way, in the synthesis of chlorophyll and/or in carboxilative metabolism of photosynthesis (Calvin cycle), which contributed to dry biomass reductions. Total amount of water absorbed and biomass production by plants were also decreased as glyphosate doses increased, with a more intense effect of single application, as compared to sequential. WUE was also significantly reduced with increasing glyphosate doses. Under single and sequential application, soybean plants need 13 to 20% and 8 to 14% more water to produce the same amount of biomass, respectively

Toxicity and toxin identification in Colomesus asellus, an Amazonian (Brazil) freshwater puffer fish.

Made available in DSpace on 2018-06-06T01:02:49Z (GMT). No. of bitstreams: 1 ID279241.pdf: 234136 bytes, checksum: b827af36b844a7341ebcd81f6eeb6614 (MD5) Previous issue date: 2007-02-01bitstream/item/178130/1/ID-27924-1.pd