871 research outputs found

    Exploiting Attitude Sensing in Vision-Based Navigation for an Airship

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    An Attitude Heading Reference System (AHRS) is used to compensate for rotational motion, facilitating vision-based navigation above smooth terrain by generating virtual images to simulate pure translation movement. The AHRS combines inertial and earth field magnetic sensors to provide absolute orientation measurements, and our recently developed calibration routine determines the rotation between the frames of reference of the AHRS and the monocular camera. In this way, the rotation is compensated, and the remaining translational motion is recovered by directly finding a rigid transformation to register corresponding scene coordinates. With a horizontal ground plane, the pure translation model performs more accurately than image-only approaches, and this is evidenced by recovering the trajectory of our airship UAV and comparing with GPS data. Visual odometry is also fused with the GPS, and ground plane maps are generated from the estimated vehicle poses and used to evaluate the results. Finally, loop closure is detected by looking for a previous image of the same area, and an open source SLAM package based in 3D graph optimization is employed to correct the visual odometry drift. The accuracy of the height estimation is also evaluated against ground truth in a controlled environment

    Identification of iGb3 and iGb4 in melanoma B16F10-Nex2 cells and the iNKT cell-mediated antitumor effect of dendritic cells primed with iGb3

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    <p>Abstract</p> <p>Background</p> <p>CD1d-restricted iNKT cells are protective against murine melanoma B16F10-Nex2 growing subcutaneously in syngeneic C57Bl/6 mice as inferred from the fast tumor development in CD1d-KO in comparison with wild type animals. CD1d glycoproteins are related to the class I MHC molecules, and are involved in the presentation, particularly by dentritic cells (DC), of lipid antigens to iNKT cells. In the present work we attempted to identify the endogenous lipid mediator expressed in melanoma cells inducing such immunesurveillance response and study the possibility of protecting animals challenged with tumor cells with lipid-primed DC.</p> <p>Results</p> <p>Crude cytosolic and membrane fractions from <it>in vivo </it>growing melanoma contained iNKT-stimulating substances. Lipids were then extracted from these cells and one of the fractions (i.e. F3A) was shown to prime bone marrow-derived dendritic cells (BMDC) to stimulate iNKT murine hybridoma (DN32D3) cells to produce IL-2. The active fraction was analyzed by electrospray ionization-mass spectrometry (ESI-LIT-MS) and both iGb3 and iGb4 were identified along with GM3. When iGb3 was incubated with BMDC and tested with DN32D3 cells, IL-2 was equally produced indicating iNKT cell activation. GM3 consistently inhibited this response. To assess the antitumor response-induced by iGb3, a cytotoxicity assay <it>in vitro </it>was used with [<sup>3</sup>H]-thymidine labeled B16F10-Nex2 cells. At target/effector (iGb3-activated iNKT) cell ratio of 100<sup>-1</sup>-100<sup>-4 </sup>tumor cell lysis was shown. The antitumor activity <it>in vivo </it>was tested in mice challenged i.v. with B16F10-Nex2 cells and treated with iGb3- or α-galactosylceramide-primed DCs. A 4-fold lower tumor load in the lungs was observed with either treatment.</p> <p>Conclusion</p> <p>Our results show the expression of globo and isoglobohexosylceramides in murine melanoma B16F10-Nex2. The expression of iGb3 and its precursor, iGb4, on tumor cells may prime an effective iNKT cell-dependent antitumor response, modulated negatively by GM3 which is also produced in these cells. iGb3-primed BMDC exerted a significant iNKT cell-mediated anti-tumor activity in mice challenged with melanoma cells.</p

    Total synthesis of crocacins A, C and D: new antibiotics isolated from Chondromyces crocatus and Chondromyces pediculatus

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    This review describes the endeavors that led to the total synthesis of a novel class of antibiotic compounds: the crocacins A-D. Other aspects such as isolation, structural elucidation as well as the biological activities are also presented.854871Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    A new framework to measure intuitiveness in decision problems

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    Intuition in decision-making is often seen as a set of heuristic or holistic mental processes applied to decision problems hen they exceed cognitive capacity, or whenever there is a will to achieve a solution that does not exhaust cognitive resources. In this regard, to date it has been solely treated as a  ersonal and frequently solipsist tendency. This paper tests whether different types of problems carry different degrees of intuitiveness’ and whether it would be possible to produce a realistic experimental model of such problems. To cope with both demands, standardized stimuli (mostly IAPS figures) were used to model decision problems as conflicts (approach-avoidance, approach-approach, and avoidanceapproach conflicts). Intuitiveness was argued to be inversely related to arousal, as measured by GSR levels. several solutions to methodological problems involving decision-making designs in the environment of the software BioExplorer were created. Kruskal-Wallis and Mann-Whitney-Wilcoxon tests were used to rank problems. According to our analyses, ap-av conflicts are by far less intuitive than av-ap, and av-av (p &lt;.0001). The latter two are not very different in this regard (p = .5712).

    Intracranial hypertension

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    A relação entre o conteúdo da caixa intracraniana e o seu volume determina a pressão intracraniana (PIC), que tem como referência a pressão atmosférica. Em condições normais, a pressão intracraniana tem flutuações determinadas pelos ciclos respiratório e cardíaco. Várias doenças determinam o aumento da pressão intracraniana, sendo a mais freqüente o traumatismo craniencefálico. Para o diagnóstico da hipertensão intracraniana (HIC) deve-se valorizar o quadro clínico, constituído de cefaléia, vômitos e papiledema. Dos exames subsidiários, os mais importantes são os métodos de imagem principalmente Tomografia Computadorizada (TC) e Ressonância Nuclear Magnética (RNM). Para os casos graves de HIC, o ideal durante o tratamento é que a PIC esteja monitorizada. Diversas modalidades podem ser utilizadas, como a hipocapnia induzida pela hiperventilação, os diuréticos osmóticos, a hipotermia e cuidados especiais no tratamento geral dos pacientes.The relation between the volume of the brain and the skull determines the intracranial pressure, that has as reference the atmospheric pressure. In normal conditions the intracranial pressure has oscillations determined by the breathing and heart cycles. Several pathologies determine the increase of the intracranial pressure, the most frequent the head trauma. Should be valued for the diagnosis of the intracranial hypertension (ICH) the clinical picture of headache, vomiting and papilledema. The most important subsidiary exams are the image methods mainly the Computed Tomography (CT) and the Magnetic Resonance Imaging (MRI). Monitorization of the intracranial pressure is important for severe cases of ICH. Several therapeutic modalities can ben used, as hypocarbia induced by hyperventilation, osmotics diuretics, barbiturates, hypothermia and special general measures with the patient

    Tecnologia assistiva cães-guia no Brasil: uma ação política orientada à inclusão social de pessoas com deficiência visual

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    This article aims to present the experience of implementation and operation of the Training Centre of Trainers and Instructors of guide dogs at the Catarinense Federal Institute – Campus Camboriú. In order to achieve the proposed, we contextualize and analyze how was established the government policy that aim at social inclusion of people with disabilities and we discussed Guide dogs’ Assistive Technology, an alternative supporting mode for people with visual impairment, highlighting its impact on the lives of users.Este artículo tiene como objetivo presentar la experiencia de implementación y operación del Centro de capacitación para instructores e instructores de perros guía en el Instituto Federal de Santa Catarina - Campus Camboriú. Para lograr la propuesta, contextualizamos y analizamos cómo se estableció la política del gobierno dirigida a la inclusión social de las personas con discapacidad y discutimos la Assistive Technology Guide Dogs, una movilidad alternativa que apoya a las personas con discapacidad visual, destacando su impacto en la vida. de los usuarios.Este artigo possui como propósito apresentar a experiência de implantação e funcionamento do Centro de Formação de Treinadores e Instrutores de Cães-Guia no Instituto Federal Catarinense – Campus Camboriú. Para alcançar o proposto, contextualizamos e analisamos o modo como se estabeleceu a política governamental que visou a inclusão social de pessoas com deficiência e discutimos a Tecnologia Assistiva Cães-Guia, uma mobilidade alternativa de apoio a pessoas com deficiência visual, destacando seu impacto na vida dos usuários
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