Integration of Host Plant Resistance and Insecticides in the Control of \u3ci\u3eNephotettix virescens\u3c/i\u3e (Homoptera: Cicadelli-dae), a Vector of Rice Tungro Virus

Combined effects of levels of vector resistance and insecticide application in control of rice tungro virus (RTV) were determined in three field tests. Cultivar “IR28,” with high levels of resistance to the vector, Nephotettix virescens (Distant), had low RTV infection in all treatments including the untreated check. In moderately resistant “IR36,” RTV decreased with an increase in level of insecticide but did not decrease to a level equaling the untreated “IR28.” The N. virescens-susceptible cultivar “IR22” had extremely high levels of RTV infection at all insecticide levels. Economic analysis indicated that gross profit and net gain were highest in the N. virescens-resistant “IR28,” intermediate in moderately resistant “IR36,” and lowest in susceptible “IR22.

"Engenheiros ecológicos" e atributos químicos do solo sob diferentes sistemas de manejo.

bitstream/item/66196/1/31472.pdfFERTBIO

Macrofauna do solo associada ao Sistema Plantio Direto.

bitstream/item/38755/1/COL20026.pdfDocumento online

TiO2-Photocatalyzed degradation of phenol in saline media in an annular reactor: hydrodynamics, lumped kinetics, intermediates, and acute toxicity

The photocatalytic degradation of phenol in aqueous suspensions of TiO2 under different salt concentrations in an annular reactor has been investigated. In all cases, complete removal of phenol and mineralization degrees above 90% were achieved. The reactor operational parameters were optimized and its hydrodynamics characterized in order to couple mass balance equations with kinetic ones. The photodegradation of the organics followed a Langmuir-Hinshelwood-Hougen-Watson lumped kinetics. From GC/MS analyses, several intermediates formed during oxidation have been identified. The main ones were catechol, hydroquinone, and 3-phenyl-2-propenal, in this order. The formation of negligible concentrations of 4-chlorophenol was observed only in high salinity medium. Acute toxicity was determined by using Artemia sp. as the test organism, which indicated that intermediate products were all less toxic than phenol and a significant abatement of the overall toxicity was accomplished, regardless of the salt concentration.(FAPERJ) Fundacao de Amparo a Pesquisa do Estado do Rio de JaneiroFUJBCNPqPADC

Aging and Rejuvenation with Fractional Derivatives

We discuss a dynamic procedure that makes the fractional derivatives emerge in the time asymptotic limit of non-Poisson processes. We find that two-state fluctuations, with an inverse power-law distribution of waiting times, finite first moment and divergent second moment, namely with the power index mu in the interval 2<mu <3, yields a generalized master equation equivalent to the sum of an ordinary Markov contribution and of a fractional derivative term. We show that the order of the fractional derivative depends on the age of the process under study. If the system is infinitely old, the order of the fractional derivative, ord, is given by ord=3-mu . A brand new system is characterized by the degree ord=mu -2. If the system is prepared at time -ta<0$ and the observation begins at time t=0, we derive the following scenario. For times 0<t<<ta the system is satisfactorily described by the fractional derivative with ord=3-mu . Upon time increase the system undergoes a rejuvenation process that in the time limit t>>ta yields ord=mu -2. The intermediate time regime is probably incompatible with a picture based on fractional derivatives, or, at least, with a mono-order fractional derivative.Comment: 11 pages, 4 figure

O potencial da cajucultura nas savanas tropicais.

Cajueiro;Savanas;Savanas brasileiras-O cerrado;Caracterizacao ambiental dos cerrados; Cajueiro nos cerrados;Atuacao da Embrapa Agroindustria Tropical nos cerrados;Oportunidades para a industrializacao do caju nas savanas tropicais.bitstream/item/35436/1/Dc-044.pd

Bioindicadores de impacto ambiental em sistemas agrícolas orgânicos.

Função dos bioindicadores; Bioindicadores em sistemas orgânicos; Impacto ambiental ocasionado pela intervenção antrópica; Erosão, um indicador de impacto ambiental; Plantas controladoras de desequilíbrio agrícola;bitstream/CNPAT-2010/9208/1/Dc-093.pd