Otacílio Antunes Santana

Tratamento de ruídos e caracterização de fisionomias do Cerrado utilizando séries temporais do sensor MODIS

Cerrado is formed by a mosaic of grassland, shrubland and woodland physiognomies with a typical phenological cycle. Thus, MODIS data provide daily measurements which allows to monitor the seasonal phenology of the vegetation. The objective of this work was to characterize savanna formations, forest formations and cerrado areas converted by anthropic actions, by using temporal series of MODIS NDVI and EVI after noise reduction. The adopted methodology should be divided into the following steps: (a) elaboration of the temporal cube with NDVI and EVI, in which the z profile corresponds to temporal signature, (b) noise elimination, (c) detection of temporal signature. The Minimum Noise Fraction Transformation (MNF) method was applied to reduce noise in temporal signature. The results showed that the NDVI values were higher than the EVI; and there was a relationship with the seasons of the year. The forest formations presented the highest values of NDVI and EVI, showing the lowest variations among the seasons. The converted areas of Cerrado presented the lowest values in both indices, and their values decreased in the beginning of the dry season, probably because it was the harvesting season. The study concluded that the NDVI and EVI temporal series are useful in differentiation among vegetation types.

Quality and Language of Learning Objects Used in the Teaching of Human Anatomy

El metodo tradicional de ensenanza de la Anatomia Humana se basa en el uso de cadaveres, libros de texto y en la utilizacion de imagenes de atlas. Aprender anatomia por medio del empleo de cadaveres contribuye a la comprension de la forma, localizacion y relacion de los organos y estructuras del cuerpo humano. Sin embargo, las dificultades que se observan en la utilizacion de material cadaverico estan relacionadas a su obtencion, conservacion, calidad y cantidad. En ese sentido, para mejorar la ensenanza de la anatomia se utilizan otros objetos de aprendizaje como modelos anatomicos, videos y softwares. Cada uno de esos objetos tiene cualidades como facilitadores del conocimiento, este hecho se plasma en la obtencion de mejores calificaciones por parte de los alumnos. No obstante, estos materiales no deben sustituir al material cadaverico, por el contrario, debe existir una integracion de todos los metodos, con el objetivo de mejorar el desempeno del alumno. Este articulo presenta una revision de la literatura sobre la calidad y el lenguaje de los objetos de aprendizaje utilizados para mejorar la ensenanza de la Anatomia Humana, ademas de analizar la influencia que los computadores ejercen para que los objetivos y contenidos del aprendizaje de la disciplina de Anatomia sean cumplidos.

Multimodal highly fluorescent-magnetic nanoplatform to target transferrin receptors in cancer cells

BACKGROUND Site-specific multimodal nanoplatforms with fluorescent-magnetic properties have great potential for biological sciences. For this reason, we developed a multimodal nanoprobe (BNPs-Tf), by covalently conjugating an optical-magnetically active bimodal nanosystem, based on quantum dots and iron oxide nanoparticles, with the human holo-transferrin (Tf). METHODS The Tf bioconjugation efficiency was evaluated by the fluorescence microplate assay (FMA) and the amount of Tf immobilized on BNPs was quantified by fluorescence spectroscopy. Moreover, relaxometric and fluorescent properties of the BNPs-Tf were evaluated, as well as its ability to label specifically HeLa cells. Cytotoxicity was also performed by Alamar Blue assay. RESULTS The FMA confirmed an efficient bioconjugation and the fluorescence spectroscopy analysis indicated that 98% of Tf was immobilized on BNPs. BNPs-Tf also presented a bright fluorescence and a transversal/longitudinal relaxivities ratio (r2/r1) of 65. Importantly, the developed BNPs-Tf were able to label, efficiently and specifically, the Tf receptors in HeLa cells, as shown by fluorescence and magnetic resonance imaging assays. Moreover, this multimodal system did not cause noteworthy cytotoxicity. CONCLUSIONS The prepared BNPs-Tf hold great promise as an effective and specific multimodal, highly fluorescent-magnetic, nanoplatform for fluorescence analyses and T2-weighted images. GENERAL SIGNIFICANCE This study developed an attractive and versatile multimodal nanoplatform that has potential to be applied in a variety of in vitro and in vivo studies, addressing biological processes, diagnostic, and therapeutics. Moreover, this work opens new possibilities for designing other efficient multimodal nanosystems, considering other biomolecules in their composition able to provide them important functional properties.

Passagem do fogo sobre fraturas geomórficas no Cerrado: efeitos sobre a vegetação

Geomorphic fracture is a natural geologic formation that sometimes forms a deep fissure in the rock with the establishment of soil and vegetation. The objective of this work was to analyze vegetation within geomorphic fractures under the effect of wildfire passage. The biometric variables evaluated before and after fire passage were: diameter, height, leaf area index, timber volume, grass biomass, number of trees and shrubs and of species. Results (in fractures) were compared to adjacent areas (control). The effect of wildfire passage on vegetation within geomorphic fractures was not significant because fire followed plant biomass bed and when it met the fracture (wetter), it changed from soil surface to canopy surface (jump fire effect), affecting without significance the number of plants or species; so, fracture could be plants refuge against fire passage. We could infer in our experimental model that quality of plant biomass bed could be more significant than quantity, and microclimate variability recruits plants to the refuge (geomorphic fracture). Passagem do fogo sobre fraturas geomórficas no Cerrado: efeitos sobre a vegetação Resumo A fratura geomórfica é uma formação geológica natural, que em alguns casos forma uma fissura profunda na rocha, com o estabelecimento de solo e vegetação. O objetivo desse trabalho foi analisar a vegetação dentro das fraturas geomórficas sobre o efeito da passagem do fogo. Para isso, as seguintes variáveis biométricas foram avaliadas: diâmetro, altura, índice de área foliar, volume de madeira, biomassa herbácea, número de indivíduos e de espécies arbóreas e arbustivas, antes e depois da passagem do fogo. Esses dados foram comparados com as áreas adjacentes às fraturas (controle). O efeito da passagem do fogo sob a vegetação dentro da fratura geomórfica não foi significativa, pois o fogo seguiu a superfície do solo (cama de fogo formada pela biomassa das plantas) e quando encontrou com a fratura (mais úmida) mudou da superfície do solo para o dossel (pelo efeito de saltar do fogo), afetando não significativamente o número de indivíduos e espécies vegetais; então, a fratura poderia ser um refúgio para as plantas contra a passagem do fogo. Pode-se inferir em nosso modelo experimental de que a qualidade da cama de biomassa vegetal poderia ser mais importante do que a quantidade, e a variabilidade do microclima recruta as plantas para o refúgio (fratura geomórfica). ISSN: 1983-2605 (online)

Influência do vento no volume de toras e no fator de forma de Pinus caribaea var. hondurensis

The objectives of this research were to quantify wind speed and to observe its influence on the form factor and on the volume of logs along the stem, in boundary and within Pinus caribaea var. hondurensis plantation situated in the county of Jaborandi City (BA). The wind speed data was measured by anemometers; the log volume by xilometer, and the form factor was got by division of log volumes measured with xilometer by adjust volume of trunk section by cylinder. Significant differences between the samples studied in boundary and within of plantation, were evidenced by a statistical non parametric test. The sigmoidal and inversely proportional relationship was observed between wind speed and the variables volume and form factor of trunk section of P. caribaea var. hondurensis, in other words, when the higher value of the wind speed is registered, lower values of form factor and the log volume were measured.