Tratamento de imagens landsat para identificação de açaizal em floresta de várzea.

O estuário amazônico é formado por um emaranhado de ilhas, onde existem as florestas de várzeas, áreas de especial importância devido aos elevados valores de produtividade e fertilidade dos solos. Entre os produtos não madeireiros mais importantes dessas áreas destaca-se o açaizeiro (Euterpe oleracea). Nos últimos anos verifica-se uma grande expansão dos açaizais como resultado do crescimento do mercado do açaí no estado do Amapá. Tal expansão pode ser explicada tanto pelo plantio de novas áreas como pelo manejo de açaizais nativos, resultando no aumento da densidade de indivíduos de açaí e redução dos indivíduos das espécies florestais. O mapeamento realizado por meio de imagens de sensoriamento remoto, ainda que com limitações, pode facilitar a avaliação mais aprofundada das áreas de várzeas, tendo em conta o potencial produtivo da mesma. O presente estudo tem como foco os açaizais, nativos e manejados, concentrados na foz do rio Mazagão Velho, uma área de várzea localizada no sudeste do município de Mazagão, estado do Amapá, no estuário do rio Amazonas, onde estão estabelecidos transectos para estudo de manejo florestal e ecologia em áreas de várzea por meio do projeto Florestam executado pela EMBRAPA-Amapá. Para o estudo utilizou-se imagens Landsat 5/TM, do ano 2004 e 2008, selecionadas considerando a menor cobertura de nuvens possível, e imagem Landsat 8/OLI para o ano 2013. O processamento digital das imagens incluiu correção geométrica, fusão entre imagens de 30 e 15m, transformação para imagens-fração de vegetação, solo e agua pura, seguido da aplicação de técnicas de segmentação e classificação por região, com a utilização dos softwares SPRING e ENVI. O mapa resultante da classificação foi organizado em classes de cobertura de solo: floresta de várzea, açaizal em várzea, solo exposto e água. A validação do mapa foi estimada a partir de informações coletadas em campo: pontos de descrição da classe de cobertura de açaizal em várzea. Esses pontos permitiram a geração da matriz de confusão para avaliar a qualidade da classificação. O trabalho apresenta o mapa resultante do processamento das imagens e os resultados mostram que a cobertura de açaizal em várzea sofreu aumento significativo nos últimos anos.GC102

Brain correlates of task-load and dementia elucidation with tensor machine learning using oddball BCI paradigm

Dementia in the elderly has recently become the most usual cause of cognitive decline. The proliferation of dementia cases in aging societies creates a remarkable economic as well as medical problems in many communities worldwide. A recently published report by The World Health Organization (WHO) estimates that about 47 million people are suffering from dementia-related neurocognitive declines worldwide. The number of dementia cases is predicted by 2050 to triple, which requires the creation of an AI-based technology application to support interventions with early screening for subsequent mental wellbeing checking as well as preservation with digital-pharma (the so-called beyond a pill) therapeutical approaches. We present an attempt and exploratory results of brain signal (EEG) classification to establish digital biomarkers for dementia stage elucidation. We discuss a comparison of various machine learning approaches for automatic event-related potentials (ERPs) classification of a high and low task-load sound stimulus recognition. These ERPs are similar to those in dementia. The proposed winning method using tensor-based machine learning in a deep fully connected neural network setting is a step forward to develop AI-based approaches for a subsequent application for subjective- and mild-cognitive impairment (SCI and MCI) diagnostics.Comment: In ICASSP 2019 - 2019 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), pp. 8578-8582, May 201

Two PTP receptors mediate CSPG inhibition by convergent and divergent signaling pathways in neurons

Receptor protein tyrosine phosphatase σ (PTPσ) and its subfamily member LAR act as transmembrane receptors that mediate growth inhibition of chondroitin sulfate proteoglycans (CSPGs). Inhibition of either receptor increases axon growth into and beyond scar tissues after CNS injury. However, it is unclear why neurons express two similar CSPG receptors, nor whether they use the same or different intracellular pathways. We have now studied the signaling pathways of these two receptors using N2A cells and primary neurons derived from knockout mice. We demonstrate that both receptors share certain signaling pathways (RhoA, Akt and Erk), but also use distinct signals to mediate CSPG actions. Activation of PTPσ by CSPGs selectively inactivated CRMP2, APC, S6 kinase and CREB. By contrast LAR activation inactivated PKCζ, cofilin and LKB1. For the first time, we propose a model of the signaling pathways downstream of these two CSPG receptors. We also demonstrate that deleting both receptors exhibits additive enhancement of axon growth in adult neuronal cultures in vitro. Our findings elucidate the novel downstream pathways of CSPGs and suggest potential synergy of blocking their two PTP receptors.This work was supported by research grants to SL from NIH (1R01NS079432, 1R21NS066114 and 1R01EY024575) and Shriners Research Foundation (SHC-86300-PHI and SHC-86200-PHI-16), and to MES from NIH (1R01NS092876) and Shriners Research Foundation (SHC-85400)

Correspondenceless 3D-2D registration based on expectation conditional maximization

Cum Laude Poster AwardConference Theme: Visualization, Image-Guided Procedures, and Modeling3D-2D registration is a fundamental task in image guided interventions. Due to the physics of the X-ray imaging, however, traditional point based methods meet new challenges, where the local point features are indistinguishable, creating difficulties in establishing correspondence between 2D image feature points and 3D model points. In this paper, we propose a novel method to accomplish 3D-2D registration without known correspondences. Given a set of 3D and 2D unmatched points, this is achieved by introducing correspondence probabilities that we model as a mixture model. By casting it into the expectation conditional maximization framework, without establishing one-to-one point correspondences, we can iteratively refine the registration parameters. The method has been tested on 100 real X-ray images. The experiments showed that the proposed method accurately estimated the rotations (< 1°) and in-plane (X-Y plane) translations (< 1 mm). © 2011 SPIE.published_or_final_versionThe SPIE Medical Imaging 2011, Lake Buena Vista, FL., 12-17 February 2011. In Progress in Biomedical Optics and Imaging, 2011, v. 7964, art. no. 79642

Stabilization of Microtubule-Unbound Tau via Tau Phosphorylation at Ser262/356 by Par-1/MARK Contributes to Augmentation of AD-Related Phosphorylation and Aβ42-Induced Tau Toxicity.

Abnormal accumulation of the microtubule-interacting protein tau is associated with neurodegenerative diseases including Alzheimer\u27s disease (AD). β-amyloid (Aβ) lies upstream of abnormal tau behavior, including detachment from microtubules, phosphorylation at several disease-specific sites, and self-aggregation into toxic tau species in AD brains. To prevent the cascade of events leading to neurodegeneration in AD, it is essential to elucidate the mechanisms underlying the initial events of tau mismetabolism. Currently, however, these mechanisms remain unclear. In this study, using transgenic Drosophila co-expressing human tau and Aβ, we found that tau phosphorylation at AD-related Ser262/356 stabilized microtubule-unbound tau in the early phase of tau mismetabolism, leading to neurodegeneration. Aβ increased the level of tau detached from microtubules, independent of the phosphorylation status at GSK3-targeted SP/TP sites. Such mislocalized tau proteins, especially the less phosphorylated species, were stabilized by phosphorylation at Ser262/356 via PAR-1/MARK. Levels of Ser262 phosphorylation were increased by Aβ42, and blocking this stabilization of tau suppressed Aβ42-mediated augmentation of tau toxicity and an increase in the levels of tau phosphorylation at the SP/TP site Thr231, suggesting that this process may be involved in AD pathogenesis. In contrast to PAR-1/MARK, blocking tau phosphorylation at SP/TP sites by knockdown of Sgg/GSK3 did not reduce tau levels, suppress tau mislocalization to the cytosol, or diminish Aβ-mediated augmentation of tau toxicity. These results suggest that stabilization of microtubule-unbound tau by phosphorylation at Ser262/356 via the PAR-1/MARK may act in the initial steps of tau mismetabolism in AD pathogenesis, and that such tau species may represent a potential therapeutic target for AD

Simulation and Design of a Simple and Easy-to-use Small-scale Neutron Source at Kyoto University

AbstractA simple and easy-to-use compact neutron source based on a low power level proton accelerator (proton energy 3.5 MeV and 0.35kW beam power) at Kyoto University was designed with the conception of low cost, compact size, high safety and intensive thermal neutron flux via Monte Carlo method with PHITS code. By utilizing (p, n) reactions in a beryllium target coupled to a polyethylene moderator and graphite reflector with a wing configuration, this facility is expected to produce time-averaged thermal neutron fluxes suitable for neutron scattering and development of instrumentation, and play a role in educating students in neutron science and performing research with neutrons. Borated polyethylene (BPE) and ordinary concrete were combined to shield the neutron and photon. By using niobium as target backing and water as cooler, it is promising to cope with the problem of thermal damage and hydrogen embrittlement damage. The sizes of moderator and reflector are optimized to have thermal neutron flux as high as possible, while keeping the low ratio of fast neutron flux to thermal neutron flux. The neutron and gamma dose equivalent rates were evaluated and the current shielding configuration is acceptable

Measurement of neutron diffraction with compact neutron source RANS

Diffraction is used as a measurement technique for crystal structure. X-rays or electron beam with wavelength that is close to the lattice constant of the crystal is often used for the measurement. They have sensitivity in surface (0.01mm) of heavy metals due to the mean free path for heavy ions. Neutron diffraction has the probe of the internal structure of the heavy metals because it has a longer mean free path than that of the X-rays or the electrons. However, the neutron diffraction measurement is not widely used because large facilities are required in the many neutron sources. RANS (Riken Accelerator-driven Compact Neutron Source) is developed as a neutron source which is usable easily in laboratories and factories. In RANS, fast neutrons are generated by 7MeV protons colliding on a Be target. Some fast neutrons are moderated with polyethylene to thermal neutrons. The thermal neutrons of 10meV which have wavelength of 10nm can be used for the diffraction measurement. In this study, the texture evolution in steels was measured with RANS and the validity of the compact neutron source was proved. The texture of IF steel sheets with the thickness of 1.0mm was measured with 10minutes run. The resolution is 2% and is enough to analyze a evolution in texture due to compression/tensile deformation or a volume fraction of two phases in the steel sample. These results have proven the possibility to use compact neutron source for the analysis of mesoscopic structure of metallic materials