Detection of Sand Dunes on Mars Using a Regular Vine-based Classification Approach

This paper deals with the problem of detecting sand dunes from remotely sensed images of the surface of Mars. We build on previous approaches that propose methods to extract informative features for the classification of the images. The intricate correlation structure exhibited by these features motivates us to propose the use of probabilistic classifiers based on R-vine distributions to address this problem. R-vines are probabilistic graphical models that combine a set of nested trees with copula functions and are able to model a wide range of pairwise dependencies. We investigate different strategies for building R-vine classifiers and compare them with several state-of-the-art classification algorithms for the identification of Martian dunes. Experimental results show the adequacy of the R-vine-based approach to solve classification problems where the interactions between the variables are of a different nature between classes and play an important role in that the classifier can distinguish the different classes

Indicações de gestão para um laboratório, a partir do cadastro de clientes e de serviços: estudo de caso da clínica fitossanitária Embrapa Clima Temperado.

bitstream/item/31621/1/comunicado91.pd

Normocalcemic versus Hypercalcemic Primary Hyperparathyroidism: More Stone than Bone?

Introduction. Normocalcemic primary hyperparathyroidism (NPHPT) is considered a variant of the more frequent form of the disease characterized by normal serum calcium levels with high PTH. The higher prevalence of renal stones in patients with HPTP and the well established association with bone disorders show the importance of studies on how to manage asymptomatic patients. Objective. To compare the clinical and laboratory data between the normocalcemic and mild hypercalcemic forms of PHPT. Methods. We retrospectively evaluated 70 patients with PHPT, 33 normocalcemic and 37 mild hypercalcemic. Results. The frequency of nephrolithiasis was 18.2% in normocalcemic patients and 18.9% in the hypercalcemic ones (P = 0.937). Fifteen percent of normocalcemic patients had a previous history of fractures compared to 10.8% of hypercalcemic patients, although there was no statistically significant difference (P = 0.726). Conclusion. Our data confirms a high prevalence of urolithiasis in normocalcemic primary hyperparathyroidism, but with the preservation of cortical bone. This finding supports the hypothesis that this disease is not an idle condition and needs treatment

Características produtivas de cultivares de cebola sob dois métodos de manejo irrigação.

Suplemento. Edição dos Trabalhos do 50. Congresso Brasileiro de Olericultura, Guarapari, jul. 2010

Cultivares de cebola sob diferentes métodos de manejo irrigação.

Suplemento. Edição dos Trabalhos do 50. Congresso Brasileiro de Olericultura, Guarapari, jul. 2010

Biodegradation and antimicrobial properties of zinc oxide–polymer composite materials for urinary stent applications

Research advancements in the field of urinary stents have mainly been in the selection of materials and coatings to address commonly faced problems of encrustation and bacterial adhesion. In this study, polylactic acid (PLA) and polypropylene (PP) were evaluated with zinc oxide (ZnO) coating to assess its ability to reduce or eliminate the problems of encrustation and bacteria adhesion. PLA and PP films were prepared via twin screw extrusion. ZnO microparticles were prepared using sol-gel hydrothermal synthesis. The as-prepared ZnO microparticles were combined in the form of a functional coating and deposited on both polymer substrates using a doctor blade technique. The ZnO-coated PP and PLA samples as well as their uncoated counterparts were characterized from the physicochemical standpoints, antibacterial and biodegradation properties. The results demonstrated that both the polymers preserved their mechanical and thermal properties after coating with ZnO, which showed a better adhesion on PLA than on PP. Moreover, the ZnO coating successfully enhanced the antibacterial properties with respect to bare PP/PLA substrates. All the samples were investigated after immersion in simulated body fluid and artificial urine. The ZnO layer was completely degraded following 21 days immersion in artificial urine irrespective of the substrate, with encrustations more evident in PP and ZnO-coated PP films than PLA and ZnO-coated PLA films. Overall, the addition of ZnO coating on PLA displayed better adhesion, antibacterial activity and delayed the deposition of encrustations in comparison to PP substrates