Quaternion-Based Robust Attitude Estimation Using an Adaptive Unscented Kalman Filter

This paper presents the Quaternion-based Robust Adaptive Unscented Kalman Filter (QRAUKF) for attitude estimation. The proposed methodology modifies and extends the standard UKF equations to consistently accommodate the non-Euclidean algebra of unit quaternions and to add robustness to fast and slow variations in the measurement uncertainty. To deal with slow time-varying perturbations in the sensors, an adaptive strategy based on covariance matching that tunes the measurement covariance matrix online is used. Additionally, an outlier detector algorithm is adopted to identify abrupt changes in the UKF innovation, thus rejecting fast perturbations. Adaptation and outlier detection make the proposed algorithm robust to fast and slow perturbations such as external magnetic field interference and linear accelerations. Comparative experimental results that use an industrial manipulator robot as ground truth suggest that our method overcomes a trusted commercial solution and other widely used open source algorithms found in the literature

GEOMETRIC EVALUATION OF T AND H-SHAPED CAVITIES INSERTED IN A SOLID WITH HEAT GENERATION APPLYING CONSTRUCTAL DESIGN

In this work, the influence of geometry on the behavior of the temperature field in a square plate with T and H-shaped cavities is studied. The ratio between the cavity area and the plate area will be kept constant and its geometry will be varied in order to find the optimum geometry (the one that results in the temperature field with the lowest maximum temperature). The cavity will occupy 10% of the area of the plate and will be varied from the T-shaped configuration to the H-shaped one. According to the Constructal Design principles, the degrees of freedom of the problem and its restrictions will be defined. The height of the initial T was selected as H1, where H1/L1 is one of the degrees of freedom for the problem. The second degree of freedom is the ratio H2/L2, the ratio of height by the width of the first bifurcation, and the other geometric ratio (H3/L3) is the ratio of height by the width of the second bifurcation and is a function of H1. For the simulations, a code based on the Finite Element Method (FEM) was used to solve the energy conservation equation. The results showed that it is possible to minimize the maximum excess temperature by 54.4% when an H-shaped geometry with irregular legs is used compared with the T-shaped cavity. In order to reach the optimum geometry, H1/L1 was reduced by 68.37%, and H2/L2 was increased in 64.71% when compared to the initially proposed T-shaped cavity

Plantas medicinais: uso e manipulação.

Implantação do horto, Manipulação das plantas medicinais, Ações de responsabilidade social da Albras. Publicado também como folder (FD 00418).bitstream/item/28089/1/com.tec.128.pdfDisponível também on-line

Non-Anticoagulant Heparan Sulfate from the Ascidian Phallusia nigra Prevents Colon Carcinoma Metastasis in Mice by Disrupting Platelet-Tumor Cell Interaction

Although metastasis is the primary cause of death in patients with malignant solid tumors, efficient anti-metastatic therapies are not clinically available currently. Sulfated glycosaminoglycans from marine sources have shown promising pharmacological effects, acting on different steps of the metastatic process. Oversulfated dermatan sulfates from ascidians are effective in preventing metastasis by inhibition of P-selectin, a platelet surface protein involved in the platelet-tumor cell emboli formation. We report in this work that the heparan sulfate isolated from the viscera of the ascidian Phallusia nigra drastically attenuates metastases of colon carcinoma cells in mice. Our in vitro and in vivo assessments demonstrate that the P. nigra glycan has very low anticoagulant and antithrombotic activities and a reduced hypotension potential, although it efficiently prevented metastasis. Therefore, it may be a promising candidate for the development of a novel anti-metastatic drug

Adubação orgânica e fertirrigação potássica em videira Syrah no Semiárido.

Apesar da grande importância da adubação na qualidade das uvas ainda existem poucos estudos sobre a fertirrigação em videira de vinho no Vale do Submédio São Francisco. Com o objetivo de avaliar a produção de uvas sob a influência de doses de potássio e de adubo orgânico, um experimento foi realizado na Embrapa Semiárido, em Petrolina - PE, com videiras (Vitis vinifera L.), Syrah, enxertadas sobre o porta - enxerto Paulsen 1103 e cultivadas no espaçamento 3 x 1 m. As plantas foram irrigadas por um sistema de gotejamento, com um emissor por planta, com vazão de 2 L.h - 1. Os tratamentos foram constituídos de cinco doses de potássio (0, 20, 40, 80 e 160 kg ha - 1) e duas doses de adubo orgânico (0 e 7,5 m 3 ha - 1). Estes tratamentos foram dispostos em parcelas subdivididas no qual o adubo orgânico constituiu as parcelas e as doses de potássio as subparcelas. Foram avaliados na colheita o número de cachos por planta, a massa total de cachos por planta, a massa média de cachos e o rendimento total das plantas. As diferentes doses de potássio aplicadas pelo sistema de irrigação e de adubo orgânico aplicados via solo não influenciaram significativamente as características avaliadas

Antitumor properties of a new non-anticoagulant heparin analog from the mollusk Nodipecten nodosus: Effect on P-selectin, heparanase, metastasis and cellular recruitment

Inflammation and cancer are related pathologies acting synergistically to promote tumor progression. In both, hematogenous metastasis and inflammation, P-selectin participates in interactions involving tumor cells, platelets, leukocytes and endothelium. Heparin has been shown to inhibit P-selectin and as a consequence it blunts metastasis and inflammation. Some heparin analogs obtained from marine invertebrates are P-selectin inhibitors and do not induce bleeding effects. The present work focuses on the P-selectin blocking activity of a unique heparan sulfate (HS) from the bivalve mollusk Nodipecten nodosus. Initially, we showed that the mollusk HS inhibited LS180 colon carcinoma cell adhesion to immobilized P-selectin in a dose-dependent manner. In addition, we demonstrated that this glycan attenuates leukocyte rolling on activated endothelium and inflammatory cell recruitment in thioglycollate-induced peritonitis in mice. Biochemical analysis indicated that the invertebrate glycan also inhibits heparanase, a key player in cell invasion and metastasis. Experimental metastasis of Lewis lung carcinoma cells was drastically attenuated by the mollusk HS through a mechanism involving inhibition of platelet-tumor-cell complex formation in blood vessels. These data suggest that the mollusk HS is a potential alternative to heparin for inhibiting P-selectin-mediated events such as metastasis and inflammatory cell recruitmen