Academic performance of 9th graders on spatial geometry: impact of personal and contextual variables

This article presents and discusses results from a study investigating the quality of spatial geometry academic performance of 9th grade students when they are about to be exposed to more complex concepts, geometric solids, and related problems in curricular learning experiences. Participants were Portuguese public school students. We also collected information about previous mathematics grades and mother’s schooling. A geometry test, a causal attribution to a school achievement test, and two reasoning tests – spatial and mechanical – were applied, and all collected data was statistically analysed and interpreted. To address the different nature of variables, we conducted a hierarchical linear regression. Results suggest that nearly 41% of variance on Spatial Geometry academic performance can be explained by the personal and contextual variables studied. The recommendation to schoolteachers involves designing learning experiences that engage students in spatial reasoning and high-order thinking skills

Isotropy summands and Einstein Equation of Invariant Metrics on Classical Flag Manifolds

It is well known that the Einstein equation on a Riemannian flag manifold $(G/K,g)$ reduces to a algebraic system, if $g$ is a $G$-invariant metric. In this paper we described this system for all flag manifolds of a classical Lie group. We also determined the number of isotropy summands for all of these spaces and proved certain properties of the set of t-roots for flag manifolds of type $B_n$, $C_n$ and $D_n$.Comment: 27 page

Retratos da lingüística textual no Brasil : GEL e ABRALIN

Orientadora: Iara Bemquerer CostaTese (doutorado) - Universidade Federal do Paraná, Setor de Ciencias Humanas, Letras e Artes, Programa de Pós-Graduaçao em Letras. Defesa: Curitiba, 2005Inclui bibliografiaÁrea de concentraçao: Estudos linguístico

Estudo taxonômico de Cyperus subg. Pycreus (P.Beauv.) A. Gray (Cyperaceae) para o Brasil

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Biologia de Fungos, Algas e Plantas, Florianópolis, 2017Cyperaceae é uma grande família cosmopolita de monocotiledôneas. No Brasil é a terceira família mais representativa do domínio fitogeográfico Pampa, sendo também representativa no Pantanal, Caatinga e Floresta Amazônica. Cyperus é o segundo maior gênero da família, com cerca de 950 espécies amplamente distribuídas. Cyperus subg. Pycreus possui cerca de 120 espécies com distribuição Pantropical. As espécies deste subgênero são caracterizadas pela combinação de ovário bicarpelar, estilete bífido, aquênios lateralmente achatados e espiguetas plurifloras. O presente trabalho teve como objetivo realizar um estudo taxonômico de Cyperus subg. Pycreus como forma de contribuir ao conhecimento da diversidade do subgênero no Brasil. O trabalho foi desenvolvido com base em levantamento bibliográfico, coletas, revisão de herbários e análises morfológicas. Foi reconhecida a ocorrência de 14 espécies (C. barrosianus, C. capillifolius, C. flavescens, C. fugax, C. jaeggii, C. lanceolatus, C. lorentzianus, C. macrostachyos, C. megapotamicus, C. mundii, C. niederleinianus, C. polystachyos, C. pumilus e C. unioloides) e três novas espécies foram descritas (C. tuckerianus, Cyperus sp. 1 e Cyperus sp. 2). Para todas as espécies são fornecidas descrições, ilustrações, dados da distribuição, habitat, informações sobre floração e frutificação, além de características macro e micromorfológicas dos frutos.Abstract: Cyperaceae is a large cosmopolitan family of monocotyledons. In Brazil, this is the third most representative family of the Pampa phytogeographic domain, being also representative in the Pantanal, Caatinga and Amazon Rainforest. Cyperus is the second largest genus of Cyperaceae, with about 950 species widely distributed. Cyperus subg. Pycreus has about 120 species with Pantropical distribution. The species of this subgenus are characterized by the combination of ovary bicarpelar, style bifid, achene laterally flattened, and by spikelets pluriflowered. The present work aimed to carry out a taxonomic study of Cyperus subg. Pycreus as a way to contribute to the knowledge of the subgenus diversity in Brazil. The work was developed based on bibliographical survey, collections in field, herbarium review and morphological analyzes. It was confirmed the occurrence of 14 species (C. barrosianus, C. capillifolius, C. flavescens, C. fugax, C. jaeggii, C. lanceolatus, C. lorentzianus, C. macrostachyos, C. megapotamicus, C. mundii, C. niederleinianus, C. polystachyos, C. pumilus and C. unioloides) and the description of three new species (C. tuckerianus, Cyperus sp. 1 and Cyperus sp. 2). For all species we provide descriptions, illustrations, distribution data, habitat, information on flowering and fruiting, and macro and micromorphological characteristics of the achenes

Application of new carbon nanomaterials to accelerate the biological removal of recalcitrant micropollutants under anaerobic conditions

Introduction: Water pollution is a serious problem worldwide. The industrialization growth, coupled with ineffective conventional wastewater treatments, often results in the contamination of water resources with different pollutants, including azo dyes. Anerobic treatments have been proposed for the biodegradation of micropollutants. However, the reactions proceed slowly due to the recalcitrant nature of these compounds. Redox mediators (RM), can be applied at very low concentrations, to accelerate the overall reactions. Carbon materials (CM) demonstrated to be excellent candidates for accelerating the reduction rates of different micropollutants during anaerobic biodegradation. Methodology: Different carbon nanotubes (CNT) with modified surface chemistry were prepared by oxidation with HNO3 (CNT_HNO3), doping with Nitrogen in a ball milling process (CNT_MB), and also, magnetic CNT by impregnation of pristine and modified CNT with 2% of iron (CNT@2%Fe; CNT@2%Fe_HNO3 and CNT@2%Fe_MB). The new CM were tested as RM (0.1 g L-1) in the biological removal of Acid Orange 10 (AO10), with anaerobic granular sludge (AGS), over 29h of reaction. Methane production was also assessed to verify the microorganisms activity and CM effect on the methanogenic activity. Results: Above 90% of the biological removal of AO10 occurred in the presence of all CM, while in the control without CM was (29±3)%. The best results were obtained with the CNT_MB, leading to (98±1)% of biological AO10 removal at a 11-fold greater degradation rate. Comparing to commercial CNT, CNT_MB has higher surface area, pore volume, and pHpzc, this last, enhancing the electrostatic interaction between the CM, AO10 and AGS, and consequently promoting the electrons shuttling. Any dye removal was observed in the abiotic assays, so the removal was not due to adsorption on the CM. The results obtained in the presence of CM@2%Fe were similar to the obtained with the corresponding CNT, but the magnetic properties facilitated their recover and reuse. Furthermore, the microorganisms viability was maintained during the assay, and methane production was not affected by the presence of different CM. Conclusion: The removal of AO10 was improved by CM, which act as RM. The surface chemistry of the developed CM was an important factor for the catalysis, so, tailoring CM for specific micropollutants seems to be a good strategy. For AO10, CNT_MB and CNT@2%Fe_MB were the most effective RM. This screening in batch trials shows the possibility of implementation in high-rate anaerobic reactors, and in a sustainable way, through the recover and reuse of the magnetic CM.info:eu-repo/semantics/publishedVersio

Prospects and Trends in the Brazilian Market for Biologically Sourced Products

The aim of this paper was to select the most interesting Brazilian biopharmaceuticals, with the best market opportunity for production. The biopharmaceuticals filgrastim, infliximab, somatropin, imiglucerase, betainterferon and factor VIII were selected because they are not produced in Brazil and thus could increase the technological capacity of domestic production. The use of a data mining tool facilitated the results achieved here, using the patents deposited in several banks worldwide as the source information. The prospects and trends of producing biopharmaceuticals in Brazil are of great interest to the country to establish a competitive industry and reduce the vulnerability of the National Health System, such as display windows of opportunity, showing the possibility of moving towards the production of biopharmaceuticals

Anaerobic digestion supplemented with carbon materials as a sustainable approach for the bioremediation of PFAS

Per- and polyfluoroalkyl substances (PFAS) are recalcitrant fluorinated organic compounds that tend to persist in soils and aquatic ecosystems and cause adverse effects on the environment and human health, so its remediation is crucial. Anaerobic digestion (AD) mediated by carbon materials (CM), has shown high efficiency in the removal of organic pollutants from wastewater. In this work, the feasibility of applying AD in the bioremediation of PFAS was studied. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) were evaluated. These compounds promoted an inhibition in the activity of acetoclastic methanogens and acetogenic communities below 15 %, at a concentration higher than the usually found in wastewater treatment plants (WWTP) (0.1 mg L-1), while hydrogenotrophic methanogens were not affected. When supplementing AD of PFAS with CM the negative effect was reduced. Moreover, the methanization percentage of sewage sludge contaminated with PFAS increased 41 % in the presence of 1.2 g L-1PFOS and AC, demonstrating the benefit of bringing AD and CM together for PFAS bioremediation.Fundação Luso-Americana para o Desenvolvimento (FLAD)info:eu-repo/semantics/publishedVersio