Learning Local Feature Descriptor with Motion Attribute for Vision-based Localization

In recent years, camera-based localization has been widely used for robotic applications, and most proposed algorithms rely on local features extracted from recorded images. For better performance, the features used for open-loop localization are required to be short-term globally static, and the ones used for re-localization or loop closure detection need to be long-term static. Therefore, the motion attribute of a local feature point could be exploited to improve localization performance, e.g., the feature points extracted from moving persons or vehicles can be excluded from these systems due to their unsteadiness. In this paper, we design a fully convolutional network (FCN), named MD-Net, to perform motion attribute estimation and feature description simultaneously. MD-Net has a shared backbone network to extract features from the input image and two network branches to complete each sub-task. With MD-Net, we can obtain the motion attribute while avoiding increasing much more computation. Experimental results demonstrate that the proposed method can learn distinct local feature descriptor along with motion attribute only using an FCN, by outperforming competing methods by a wide margin. We also show that the proposed algorithm can be integrated into a vision-based localization algorithm to improve estimation accuracy significantly.Comment: This paper will be presented on IROS1

In-vivo Optical Tomography of Small Scattering Specimens: time-lapse 3D imaging of the head eversion process in Drosophila melanogaster

5 fig.Even though in vivo imaging approaches have witnessed several new and important developments, specimens that exhibit high light scattering properties such as Drosophila melanogaster pupae are still not easily accessible with current optical imaging techniques, obtaining images only from subsurface features. This means that in order to obtain 3D volumetric information these specimens need to be studied either after fixation and a chemical clearing process, through an imaging window - thus perturbing physiological development -, or during early stages of development when the scattering contribution is negligible. In this paper we showcase how Optical Projection Tomography may be used to obtain volumetric images of the head eversion process in vivo in Drosophila melanogaster pupae, both in control and headless mutant specimens. Additionally, we demonstrate the use of Helical Optical Projection Tomography (hOPT) as a tool for high throughput 4D-imaging of several specimens simultaneously.This work was supported in part by Project ‘‘THALES – BSRC ‘Alexander Fleming’ – Development and employment of Minos-based genetic and functional genomic technologies in model organisms (MINOS)’’ – MIS: 376898, the Fellowship for Young International Scientist of the Chinese Academy of Sciences Grant No. 2010Y2GA03 and the NSFC-NIH Biomedical collaborative research program 81261120414. A. Arranz acknowledges support from Marie Curie Intra-European Fellowship Program FP7-PEOPLE-2010-IEF. J. Ripoll acknowledges support from EC FP7 CIG grant HIGH-THROUGHPUT TOMO, and Spanish MINECO grant MESO-IMAGING FIS2013-41802-R. The authors would like to thank Dr. S. Oehler for the help with the GFP-expressing flies, and G. Livadaras and G. Zacharakis for help with the Drosophila stocks

Helical Optical Projection Tomography

A new technique termed Helical Optical Projection Tomography (hOPT) has been developed with the aim to overcome some of the limitations of current 3D optical imaging techniques. hOPT is based on Optical Projection Tomography (OPT) with the major difference that there is a translation of the sample in the vertical direction during the image acquisition process, requiring a new approach to image reconstruction. Contrary to OPT, hOPT makes possible to obtain 3D-optical images of intact long samples without imposing limits on the sample length. This has been tested using hOPT to image long murine tissue samples such as spinal cords and large intestines. Moreover, 3D-reconstructed images of the colon of DSS-treated mice, a model for Inflammatory Bowel Disease, allowed the identification of the structural alterations. Finally, the geometry of the hOPT device facilitates the addition of a Selective Plane Illumination Microscopy (SPIM) arm, providing the possibility of delivering high resolution images of selected areas together with complete volumetric informationThis work was partially supported by EC FP7 collaborative grant FMT-XCT and the Bill and Melinda Gates foundation. A.A. wishes to acknowledge support from Marie Curie IEF-2010-275137. J.R. wishes to acknowledge support from EC FP7 IMI project PREDICT-TB, and the EC FP7 CIG grant HIGH-THROUGHPUT TOMO. D.D., S.Z. and J.T. acknowledge support from the National Basic Research Program of China (973 Program) under Grant 2011CB707700, the Fellowship for Young International Scientists of the Chinese Academy of Sciences under Grant 2010Y2GA03, the National Natural Science Foundation of China under Grant 81101084 and Instrument Developing Project of the Chinese Academy of Sciences under Grant No. YZ201164Publicad

Making Nanosized CHA Zeolites with Controlled Al Distribution for Optimizing Methanol-to-Olefin Performance

[EN] From theoretical calculations and a rational synthesis methodology, it has been possible to prepare nanocrystalline (60-80 nm) chabazite with an optimized framework Al distribution that has a positive impact on its catalytic properties. This is exemplified for the methanol-to-olefin (MTO) process. The nanosized material with the predicted Al distribution maximizes the formation of the required MTO hydrocarbon pool intermediates, while better precluding excessive diffusion pathways that favor the rapid catalyst deactivation by coke formation.This work has been supported by the EU through ERC-AdG-2014-671093, by the Spanish Government-MINECO through "Severo Ochoa" (SEV-2016-0683) and MAT2015-71261-R, and by the Fundacion Ramon Areces through a research contract of the "Life and Materials Science" program. E.M.G. acknowledges "La Caixa-Severo Ochoa" International PhD Fellowships (call 2015), C.L. acknowledges China Scholarship Council (CSC) for a Ph.D fellowship, and N.M. thanks MINECO for a pre-doctoral fellowship (BES-2013-064347). Red Espanola de Supercomputacion (RES) and Centre de Calcul de la Universitat de Valencia are gratefully acknowledged for computational resources.Gallego-Sánchez, EM.; Li, C.; Paris, C.; Martín-García, N.; Martínez-Triguero, J.; Boronat Zaragoza, M.; Moliner Marin, M.... (2018). Making Nanosized CHA Zeolites with Controlled Al Distribution for Optimizing Methanol-to-Olefin Performance. Chemistry - A European Journal. 24(55):14631-14635. https://doi.org/10.1002/chem.201803637S14631146352455Tian, P., Wei, Y., Ye, M., & Liu, Z. (2015). Methanol to Olefins (MTO): From Fundamentals to Commercialization. ACS Catalysis, 5(3), 1922-1938. doi:10.1021/acscatal.5b00007Olsbye, U., Svelle, S., Bjørgen, M., Beato, P., Janssens, T. V. W., Joensen, F., … Lillerud, K. P. (2012). Conversion of Methanol to Hydrocarbons: How Zeolite Cavity and Pore Size Controls Product Selectivity. Angewandte Chemie International Edition, 51(24), 5810-5831. doi:10.1002/anie.201103657Olsbye, U., Svelle, S., Bjørgen, M., Beato, P., Janssens, T. V. W., Joensen, F., … Lillerud, K. P. (2012). Umwandlung von Methanol in Kohlenwasserstoffe: Wie Zeolith-Hohlräume und Porengröße die Produktselektivität bestimmen. Angewandte Chemie, 124(24), 5910-5933. doi:10.1002/ange.201103657Moliner, M., Martínez, C., & Corma, A. (2013). Synthesis Strategies for Preparing Useful Small Pore Zeolites and Zeotypes for Gas Separations and Catalysis. Chemistry of Materials, 26(1), 246-258. doi:10.1021/cm4015095Stöcker, M. (1999). Methanol-to-hydrocarbons: catalytic materials and their behavior. Microporous and Mesoporous Materials, 29(1-2), 3-48. doi:10.1016/s1387-1811(98)00319-9Wilson, S., & Barger, P. (1999). The characteristics of SAPO-34 which influence the conversion of methanol to light olefins. Microporous and Mesoporous Materials, 29(1-2), 117-126. doi:10.1016/s1387-1811(98)00325-4Hemelsoet, K., Van der Mynsbrugge, J., De Wispelaere, K., Waroquier, M., & Van Speybroeck, V. (2013). Unraveling the Reaction Mechanisms Governing Methanol-to-Olefins Catalysis by Theory and Experiment. ChemPhysChem, 14(8), 1526-1545. doi:10.1002/cphc.201201023Haw, J. F., & Marcus, D. M. (2005). Well-defined (supra)molecular structures in zeolite methanol-to-olefin catalysis. Topics in Catalysis, 34(1-4), 41-48. doi:10.1007/s11244-005-3798-0Bleken, F., Bjørgen, M., Palumbo, L., Bordiga, S., Svelle, S., Lillerud, K.-P., & Olsbye, U. (2009). The Effect of Acid Strength on the Conversion of Methanol to Olefins Over Acidic Microporous Catalysts with the CHA Topology. Topics in Catalysis, 52(3), 218-228. doi:10.1007/s11244-008-9158-0Lok, B. M., Messina, C. A., Patton, R. L., Gajek, R. T., Cannan, T. R., & Flanigen, E. M. (1984). Silicoaluminophosphate molecular sieves: another new class of microporous crystalline inorganic solids. Journal of the American Chemical Society, 106(20), 6092-6093. doi:10.1021/ja00332a063Chen, J. Q., Bozzano, A., Glover, B., Fuglerud, T., & Kvisle, S. (2005). Recent advancements in ethylene and propylene production using the UOP/Hydro MTO process. Catalysis Today, 106(1-4), 103-107. doi:10.1016/j.cattod.2005.07.178S. I. Zones L. T. Yuen S. J. Miller WO/2003/020641 2003Takata, T., Tsunoji, N., Takamitsu, Y., Sadakane, M., & Sano, T. (2016). Nanosized CHA zeolites with high thermal and hydrothermal stability derived from the hydrothermal conversion of FAU zeolite. Microporous and Mesoporous Materials, 225, 524-533. doi:10.1016/j.micromeso.2016.01.045Wu, L., Degirmenci, V., Magusin, P. C. M. M., Szyja, B. M., & Hensen, E. J. M. (2012). Dual template synthesis of a highly mesoporous SSZ-13 zeolite with improved stability in the methanol-to-olefins reaction. Chemical Communications, 48(76), 9492. doi:10.1039/c2cc33994cLi, Z., Navarro, M. T., Martínez-Triguero, J., Yu, J., & Corma, A. (2016). Synthesis of nano-SSZ-13 and its application in the reaction of methanol to olefins. Catalysis Science & Technology, 6(15), 5856-5863. doi:10.1039/c6cy00433dZhu, X., Kosinov, N., Hofmann, J. P., Mezari, B., Qian, Q., Rohling, R., … Hensen, E. J. M. (2016). Fluoride-assisted synthesis of bimodal microporous SSZ-13 zeolite. Chemical Communications, 52(15), 3227-3230. doi:10.1039/c6cc00201cDi Iorio, J. R., & Gounder, R. (2016). Controlling the Isolation and Pairing of Aluminum in Chabazite Zeolites Using Mixtures of Organic and Inorganic Structure-Directing Agents. Chemistry of Materials, 28(7), 2236-2247. doi:10.1021/acs.chemmater.6b00181Di Iorio, J. R., Nimlos, C. T., & Gounder, R. (2017). Introducing Catalytic Diversity into Single-Site Chabazite Zeolites of Fixed Composition via Synthetic Control of Active Site Proximity. ACS Catalysis, 7(10), 6663-6674. doi:10.1021/acscatal.7b01273D. Xie S. I. Zones R. J. Saxton WO2016/032565 2016Martín, N., Li, Z., Martínez-Triguero, J., Yu, J., Moliner, M., & Corma, A. (2016). Nanocrystalline SSZ-39 zeolite as an efficient catalyst for the methanol-to-olefin (MTO) process. Chemical Communications, 52(36), 6072-6075. doi:10.1039/c5cc09719cS. I. Zones US4544538 198

Vertically scanned laser sheet microscopy

Laser sheet microscopy is a widely used imaging technique for imaging the three-dimensional distribution of a fluorescence signal in fixed tissue or small organisms. In laser sheet microscopy, the stripe artifacts caused by high absorption or high scattering structures are very common, greatly affecting image quality. To solve this problem, we report here a two-step procedure which consists of continuously acquiring laser sheet images while vertically displacing the sample, and then using the variational stationary noise remover (VSNR) method to further reduce the remaining stripes. Images from a cleared murine colon acquired with a vertical scan are compared with common stitching procedures demonstrating that vertically scanned light sheet microscopy greatly improves the performance of current light sheet microscopy approaches without the need for complex changes to the imaging setup and allows imaging of elongated samples, extending the field of view in the vertical direction.This work was supported in part by the Bill and Melinda Gates Foundation, the National Basic Research Program of China (973 Program) under Grant No. 2011CB707700, the National Natural Science Foundation of China under Grant No. 81227901, 81027002, 61231004, and 81101095, the Fellowship for Young International Scientists of the Chinese Academy of Sciences under Grant No. 2010Y2GA03, and the Instrument Developing Project of the Chinese Academy of Sciences under Grant No. YZ201164. A. Arranz acknowledges support from the Marie Curie Intra-European Fellowship program IEF-2010-275137. J.R. acknowledges support from EC FP7 IMI project PREDICT-TB, the EC FP7 CIG grant HIGHTHROUGHPUT TOMO, and the Spanish MINECO project grant FIS2013-41802-R MESO-IMAGING

Bio-inspired plasmonic nanoarchitectured hybrid system towards enhanced far red-to-near infrared solar photocatalysis

Solar conversion to fuels or to electricity in semiconductors using far red-to-near infrared (NIR) light, which accounts for about 40% of solar energy, is highly significant. One main challenge is the development of novel strategies for activity promotion and new basic mechanisms for NIR response. Mother Nature has evolved to smartly capture far red-to-NIR light via their intelligent systems due to unique micro/nanoarchitectures, thus motivating us for biomimetic design. Here we report the first demonstration of a new strategy, based on adopting nature’s far red-to-NIR responsive architectures for an efficient bio-inspired photocatalytic system. The system is constructed by controlled assembly of light-harvesting plasmonic nanoantennas onto a typical photocatalytic unit with butterfly wings’ 3D micro/nanoarchitectures. Experiments and finite-difference time-domain (FDTD) simulations demonstrate the structural effects on obvious far red-to-NIR photocatalysis enhancement, which originates from (1) Enhancing far red-to-NIR (700~1200 nm) harvesting, up to 25%. (2) Enhancing electric-field amplitude of localized surface plasmon (LSPs) to more than 3.5 times than that of the non-structured one, which promotes the rate of electron-hole pair formation, thus substantially reinforcing photocatalysis. This proof-of-concept study provides a new methodology for NIR photocatalysis and would potentially guide future conceptually new NIR responsive system designs

Theory of Current and Shot Noise Spectroscopy in Single-Molecular Quantum Dots with Phonon Mode

Using the Keldysh nonequilibrium Green function technique, we study the current and shot noise spectroscopy of a single molecular quantum dot coupled to a local phonon mode. It is found that in the presence of electron-phonon coupling, in addition to the resonant peak associated with the single level of the dot, satellite peaks with the separation set by the frequency of phonon mode appear in the differential conductance. In the ``single level'' resonant tunneling region, the differential shot noise power exhibit two split peaks. However, only single peaks show up in the ``phonon assisted'' resonant-tunneling region. An experimental setup to test these predictions is also proposed.Comment: 5 pages, 3 eps figures embedde