Mudanças das práticas discursivas de professores aprendendo matemáticas dinâmicas em um ambiente colaborativo online

Using data from an inservice professional development course, we inquire into changes in secondary teachers’ discursive practices in a latter part of the course compared to the beginning of the course. Participants interacted in a collaborative online environment, known as Virtual Math Teams with GeoGebra (VMTwG), focusing on discursive, mathematical, and collaborative practices. From a sociocultural perspective, we believe that teachers gradually develop their Technological Pedagogical Content Knowledge (TPACK) by interacting discursively in small teams. Using conventional content analysis of the teachers’ review of their recorded discourse, we investigate changes in practices from the teachers’ perspective. Our results show that teachers perceived that their discursive practices differed importantly from their practices at the beginning of the course.Usando dados de uma disciplina de desenvolvimento profissional para professores de matemática em serviço, investigamos as mudanças nas práticas discursivas dos professores de Fundamental II e Ensino Médio em uma última parte da disciplina, em comparação com o início da disciplina. Os professores interagiram em um ambiente colaborativo online, conhecido como Virtual Math Teams com GeoGebra (VMTcG), com foco em práticas discursivas, matemáticas e colaborativas. De uma perspectiva sociocultural, acreditamos que os professores desenvolvem gradualmente o seu conhecimento tecnológico, pedagógico e do conteúdo (TPACK), interagindo discursivamente em equipes pequenas. Usando a análise de conteúdo convencional da revisão dos professores sobre seu discurso gravado, investigamos as mudanças nas práticas da perspectiva dos professores. Nossos resultados mostram que os professores perceberam que suas práticas discursivas diferiam importantemente de suas práticas no início do curso

Effect of biofunctionalized implant surface on osseointegration: a histomorphometric study in dogs

Among the different properties that influence bone apposition around implants, the chemical or biochemical composition of implant surface may interfere on its acceptance by the surrounding bone. The aim of this study was to investigate if a biofunctionalization of implant surface influences the bone apposition in a dog model and to compare it with other surfaces, such as a microstructured created by the grit-blasting/acid-etching process. Eight young adult male mongrel dogs had the bilateral mandibular premolars extracted and each one received 6 implants after 12 weeks, totaling 48 implants in the experiment. Four groups of implants were formed with the same microrough topography with or without some kind of biofunctionalization treatment. After histomorphometric analysis, it was observed that the modified microstructured surface with a "low concentration of the bioactive peptide" provided a higher adjacent bone density (54.6%) when compared to the other groups (microstructured + HA coating = 46.0%, microstructured only = 45.3% and microstructured + "high concentration of the bioactive peptide" = 40.7%), but this difference was not statistically significant. In conclusion, biofunctionalization of the implant surface might interfere in the bone apposition around implants, especially in terms of bone density. Different concentrations of bioactive peptide lead to different results.Entre as diferentes propriedades de uma superfície capazes de influenciar a deposição óssea ao redor de implantes, a composição química e bioquímica pode atuar no reconhecimento do tecido ósseo circundante. O presente trabalho investigou a influência da biofuncionalização de superfícies de implante na deposição óssea ao redor dos mesmos em um modelo animal, comparando-as com outras superfícies, como a microtexturizada obtida pelo processo de jateamento e ataque ácido. Metodologicamente, os pré-molares mandibulares bilaterais de 8 cães foram extraídos e após 12 semanas foram instalados 6 implantes em cada cão, constituindo uma amostra de 48 implantes. Dos 4 grupos experimentais de diferentes superfícies, todos continham a mesma microtopografia rugosa, porém possuindo ou não alguma biofuncionalização. A análise histomorfométrica revelou que a superfície microtexturizada modificada pela adição de baixa concentração peptídica obteve uma maior densidade óssea adjacente (54,6%) quando comparada aos outros grupos (microtexturizada + HA = 46%, somente microtexturizada = 45,3% e microtexturizada com adição de alta concentração peptídica = 40,7%), no entanto estas diferenças numéricas não foram estatisticamente significantes. Dentro deste contexto, conclui-se que a biofuncionalização da superfície de implantes pode interferir na aposição óssea, em particular na densidade óssea, e que diferentes concentrações peptídicas podem conduzir a diferentes resultados.FAPES

On the Fibonacci universality classes in nonlinear fluctuating hydrodynamics

We present a lattice gas model that without fine tuning of parameters is expected to exhibit the so far elusive modified Kardar-Parisi-Zhang (KPZ) universality class. To this end, we review briefly how non-linear fluctuating hydrodynamics in one dimension predicts that all dynamical universality classes in its range of applicability belong to an infinite discrete family which we call Fibonacci family since their dynamical exponents are the Kepler ratios $z_i = F_{i+1}/F_{i}$ of neighbouring Fibonacci numbers $F_i$, including diffusion ($z_2=2$), KPZ ($z_3=3/2$), and the limiting ratio which is the golden mean $z_\infty=(1+\sqrt{5})/2$. Then we revisit the case of two conservation laws to which the modified KPZ model belongs. We also derive criteria on the macroscopic currents to lead to other non-KPZ universality classes.Comment: 17 page

Treatment of gingival recessions in heavy smokers using two surgical techniques: a controlled clinical trial

Smokers have small root coverage which is associated with bad vascularity of periodontal tissues. This study evaluated a technique that can increase the blood supply to the periodontal tissues compared with a traditional technique. Twenty heavy smokers (10 males and 10 females) with two bilateral Miller class I gingival recessions received coronally positioned flaps in one side (Control group)and extended flap technique in the other side (Test group). Clinical measurements (probing pocket depth, clinical attachment level, bleeding on probing, gingival recession height, gingival recession width, amount of keratinized tissue, and width and height of the papillae adjacent to the recession) were determined at baseline, 3 and 6 months postoperatively. Salivary cotinina samples were taken as an indicator of the nicotine exposure level. No statistically significant differences (p>0.05) were detected for the clinical measurements or smoke exposure. Both techniques promoted low root coverage (Control group: 43.18% and Test group: 44.52%). In conclusion, no difference was found in root coverage between the techniques. Root coverage is possible and uneventful even, if rather low, in heavy smoker patients with low plaque and bleeding indices

Soil biochemistry and microbial activity in vineyards under conventional and organic management at Northeast Brazil.

The São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that orgThe São Francisco Submedium Valley is located at the Brazilian semiarid region and is an important center for irrigated fruit growing. This region is responsible for 97% of the national exportation of table grapes, including seedless grapes. Based on the fact that organic fertilization can improve soil quality, we compared the effects of conventional and organic soil management on microbial activity and mycorrhization of seedless grape crops. We measured glomerospores number, most probable number (MPN) of propagules, richness of arbuscular mycorrhizal fungi (AMF) species, AMF root colonization, EE-BRSP production, carbon microbial biomass (C-MB), microbial respiration, fluorescein diacetate hydrolytic activity (FDA) and metabolic coefficient (qCO2). The organic management led to an increase in all variables with the exception of EE-BRSP and qCO2. Mycorrhizal colonization increased from 4.7% in conventional crops to 15.9% in organic crops. Spore number ranged from 4.1 to 12.4 per 50 g-1 soil in both management systems. The most probable number of AMF propagules increased from 79 cm-3 soil in the conventional system to 110 cm-3 soil in the organic system. Microbial carbon, CO2 emission, and FDA activity were increased by 100 to 200% in the organic crop. Thirteen species of AMF were identified, the majority in the organic cultivation system. Acaulospora excavata, Entrophospora infrequens, Glomus sp.3 and Scutellospora sp. were found only in the organically managed crop. S. gregaria was found only in the conventional crop. Organically managed vineyards increased mycorrhization and general soil microbial activity

Synthesis of a square-planar rhodium alkylidene N-heterocyclic carbene complex and its reactivity toward alkenes

The first rhodium alkylidene square-planar complex stabilized by an N-heterocyclic carbene ligand, RhCl(-CHPh)(IPr)PPh3 (2; IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-carbene), has been prepared by reaction of RhCl(IPr)(PPh3)2 (1) with phenyldiazomethane and its dynamic behavior in solution studied. Treatment of 2 with alkenes results in the formation of the ¿2-olefin complexes RhCl(¿2-CH2-CHR)(IPr)PPh3 (3, R = H; 4, R = Ph; 5, R = OEt) and new olefins arising from the coupling of the alkylidene with the alkenes, likely via a metallacyclobutane intermediate