Benefits of Entomophile Pollination in Crops of Brassica napus and Aspects of Plant Floral Biology

Rapeseed (Brassica napus L. var. oleifera) is an oleaginous species of the Brassicaceae family, being the third most produced oleaginous in the world. Rapeseed can produce fruits and seeds from both self-pollination and cross-pollination. However, cross-pollination rate is approximately 30% and may suffer variations due to the abundance and diversity of pollinator insects, cultivar and meteorological conditions. Different researchers have reported that pollination by insects, especially Apis mellifera honeybee, on rapeseed flowers provides an increase in productivity, improving yield and contributing to the uniformity and initial pod establishment. It is estimated that the economic value of A. mellifera honeybees for rapeseed cultivation in Brazil is US$ 8.2 million. The objective of this chapter is gathering data for a compilation of information regarding rapeseed culture and the importance of A. mellifera in Brassica napus pollination

Bolsa Família: um survey sobre os efeitos do programa de transferência de renda condicionada do Brasil

Revisam-se pesquisas sobre efeitos do Programa Bolsa Família. Há quatro evidências frequentes. A primeira é que o programa tem focalização relativamente boa, mas que pode ainda ser melhorada. A segunda é o efeito positivo sobre a aquisição (consumo) de alimentos – sem conclusões sobre a qualidade da dieta. A terceira diz respeito ao estimulo às crianças a participarem da escola (matrícula, frequência e progressão), embora pouco se saiba sobre os efeitos na aprendizagem. A ausência de efeitos sobre a fecundidade das mulheres caracteriza a quarta conclusão robusta que se pode tirar da literatura, ainda que mais estudos devam ser realizados. Em outras dimensões, as evidências não formam consenso sobre direção dos efeitos.This paper surveys the literature about the effects of Bolsa Familia Program. We found four main results. The first is that the program is relatively well targeted, but it can still be improved.The second is the positive effect on the acquisition (consumption) of food, but there is no conclusions about the quality of the diet. The third is that the program encourages children to attend school (enrollment, attendance and progression). However, little is known about the effects on learning. The absence of effects on the fecundity of the women characterizes the fourth conclusion that can be drawn from the literature, although more studies must be carried out on this topic. In other dimensions, the evidence does not form consensus on the direction of effects

Synthesis of Ultra-Fine Columbite Powder MgNb 2 O 6 by the Polymerized Complex Method

Abstract. Pure MgNb 2 O 6 powders with high specific surface area and high crystallinity have been successfully synthesized by the "Polymerized Complex (PC) Method". A solution of water, citric acid, ethylene glycol and niobium and magnesium ions, was polymerized at 130 • C by the water elimination and was calcined at 400 • C for 2 h. The precursor formed was calcined at temperatures from 700 • C to 1000 • C in air to obtain the columbite phase. Thermal analysis, Raman spectroscopy, x-ray diffraction, adsorption/desorption hysteresis and scanning electron microscopy were used to investigate the polymer decomposition and the columbite phase evolution. No evidence for phase separation of crystalline MgCO 3 and Nb 2 O 5 in Raman spectra and x-ray diffraction pattern as distinct intermediates were found, and the MgNb 2 O 6 probably is formed through a single-step decomposition of oxycarbonate intermediate, as other double oxide synthesized by the PC Method, as indicated by the thermal decomposition of the precursor

Synthesis and characterization of lead zirconate titanate powders obtained by the oxidant peroxo method

Lead zirconate titanate (PbZr(1-x)TixO(3)) was synthesized by the "oxidant peroxo method (OPM)" with "x" between 0.25 and 0.50. Titanium metal was dissolved into a hydrogen peroxide/ammonia aqueous solution, followed by the addition of lead and zirconium nitrate solution. The amorphous precipitated precursor obtained was crystallized by heat treatment between 400 and 1000 degrees C. Images of transmission microscopy showed spherical particles with average diameter between 20 and 60 nm, and the presence of necks between particles treated at 700 degrees C. All of the impressed powders were characterized by X-ray diffractometry and FT-Raman spectroscopy. Powder samples with "x" up to 0.35 showed rhombohedral structure when treated at temperatures higher than 500 degrees C, and tetragonal structure when "x" was higher than 0.40. Analysis of XRD and Raman spectroscopy of the precursor powders showed amorphous-like structures, however powders treated at 400 degrees C showed a structure identified as an intermediate pyrochlore phase, independently of the Zr and Ti mole ratio. (C) 2008 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Moderating effect of ammonia on particle growth and stability of quasi-monodisperse silver nanoparticles synthesized by the Turkevich method

A new method to stabilize silver nanoparticles by the addition of ammonia is proposed. Colloidal dispersions of silver nanoparticles were synthesized by the Turkevich method using sodium citrate to reduce silver nitrate at high pH and at 90 °C. After approximately 12 min, a diluted ammonia solution was added to the reaction flask to form soluble diamine silver (I) complexes that played an important growth moderating role, making it possible to stabilize metallic silver nanoparticles with sizes as small as 1.6 nm after 17 min of reaction. Colloidal dispersions were characterized by UV-visible absorption spectroscopy, X-ray diffraction, and transmission electronic microscopy