High-throughput variable-to-fixed entropy codec using selective, stochastic code forests

Efficient high-throughput (HT) compression algorithms are paramount to meet the stringent constraints of present and upcoming data storage, processing, and transmission systems. In particular, latency, bandwidth and energy requirements are critical for those systems. Most HT codecs are designed to maximize compression speed, and secondarily to minimize compressed lengths. On the other hand, decompression speed is often equally or more critical than compression speed, especially in scenarios where decompression is performed multiple times and/or at critical parts of a system. In this work, an algorithm to design variable-to-fixed (VF) codes is proposed that prioritizes decompression speed. Stationary Markov analysis is employed to generate multiple, jointly optimized codes (denoted code forests). Their average compression efficiency is on par with the state of the art in VF codes, e.g., within 1% of Yamamoto et al.\u27s algorithm. The proposed code forest structure enables the implementation of highly efficient codecs, with decompression speeds 3.8 times faster than other state-of-the-art HT entropy codecs with equal or better compression ratios for natural data sources. Compared to these HT codecs, the proposed forests yields similar compression efficiency and speeds

Symmetrically Processed Splitting Integrators for Enhanced Hamiltonian Monte Carlo Sampling

[EN] We construct integrators to be used in Hamiltonian (or Hybrid) Monte Carlo sampling. The new integrators are easily implementable and, for a given computational budget, may deliver five times as many accepted proposals as standard leapfrog/Verlet without impairing in any way the quality of the samples. They are based on a suitable modification of the processing technique first introduced by Butcher. The idea of modified processing may also be useful for other purposes, like the construction of high-order splitting integrators with positive coefficients.The first, third, and fourth authors were supported by project PID2019-104927GB-C21 (AEI/FEDER, UE) . The second author was supported by projects PID2019-104927GB-C22 (GNI-QUAMC) , (AEI/FEDER, UE) VA105G18, and VA169P20 (Junta de Castilla y Leon, ES) co-financed by FEDER funds.Blanes Zamora, S.; Calvo, M.; Casas, F.; Sanz-Serna, JM. (2021). Symmetrically Processed Splitting Integrators for Enhanced Hamiltonian Monte Carlo Sampling. SIAM Journal on Scientific Computing. 43(5):A3357-A3371. https://doi.org/10.1137/20M137940X30SA3357A337143

The CCSDS 123.0-B-2 Low-Complexity Lossless and Near-Lossless Multispectral and Hyperspectral Image Compression Standard: A comprehensive review

The Consultative Committee for Space Data Systems (CCSDS) published the CCSDS 123.0-B-2, “Low- Complexity Lossless and Near-Lossless Multispectral and Hyperspectral Image Compression” standard. This standard extends the previous issue, CCSDS 123.0-B-1, which supported only lossless compression, while maintaining backward compatibility. The main novelty of the new issue is support for near-lossless compression, i.e., lossy compression with user-defined absolute and/or relative error limits in the reconstructed images. This new feature is achieved via closed-loop quantization of prediction errors. Two further additions arise from the new near lossless support: first, the calculation of predicted sample values using sample representatives that may not be equal to the reconstructed sample values, and, second, a new hybrid entropy coder designed to provide enhanced compression performance for low-entropy data, prevalent when non lossless compression is used. These new features enable significantly smaller compressed data volumes than those achievable with CCSDS 123.0-B-1 while controlling the quality of the decompressed images. As a result, larger amounts of valuable information can be retrieved given a set of bandwidth and energy consumption constraints

Surface Modification of Polypropilene Non-woven Substrates by Padding with Antistatic Agents for Deposition of Polyvinyl Alcohol (PVA) Nanofiber Webs by Electrospinning

In recent years, the electrospinning process has become one of the most interesting processes to obtain nanofiber webs with interesting properties for uses in a wide variety of industrial sectors such as filtration, chemical barriers, medical devices, etc., as a consequence of the relatively high surface-to-volume ratio. Among the wide variety of polymers, polyvinyl alcohol (PVA) offers good advantages since it is water-soluble and this fact enables easy processing by electrospinning. There are many variables and parameters to be considered in order to optimize PVA nanofiber webs: some of them are related to the polymer solution, some others are related to the process, and some of them are related to the collector substrate. In this work a study on the effects of two different surface pre-treatments on a nonwoven polypropylene substrate as a collector of PVA nanofiber webs has been carried out. In particular, a chemical treatment with anionic antistatics and a physical treatment with lowpressure plasma have been investigated. The effects of these pre-treatments on morphology of PVA nanofiber webs have been evaluated by scanning electron microscopy. Results show that surface resistivity is one of the main parameters influencing the web formation as well as the nature of the electric charge achieved by the pre-treatment. The plasma treatment promotes changes in surface resistivity but it is not enough for good web deposition. Chemical pre-treatment (padding) with anionic antistatic leads to a decrease in surface resistivity up to values in the 1 × 109– 1 × 1011 Ω which is enough for good nanofiber deposition.This work was supported by the Ministerio de Ciencia y Tecnologia, grant number DPI2007-66849-C02-02.Blanes, M.; Marco, B.; Gisbert, MJ.; Bonet Aracil, MA.; Balart Gimeno, RA. (2010). Surface Modification of Polypropilene Non-woven Substrates by Padding with Antistatic Agents for Deposition of Polyvinyl Alcohol (PVA) Nanofiber Webs by Electrospinning. Textile Research Journal. 80(13):1335-1346. https://doi.org/10.1177/0040517509358801S133513468013Burger, C., Hsiao, B. S., & Chu, B. (2006). NANOFIBROUS MATERIALS AND THEIR APPLICATIONS. Annual Review of Materials Research, 36(1), 333-368. doi:10.1146/annurev.matsci.36.011205.123537Dersch, R., Steinhart, M., Boudriot, U., Greiner, A., & Wendorff, J. H. (2005). Nanoprocessing of polymers: applications in medicine, sensors, catalysis, photonics. Polymers for Advanced Technologies, 16(2-3), 276-282. doi:10.1002/pat.568Frenot, A., & Chronakis, I. S. (2003). Polymer nanofibers assembled by electrospinning. Current Opinion in Colloid & Interface Science, 8(1), 64-75. doi:10.1016/s1359-0294(03)00004-9GOPAL, R., KAUR, S., MA, Z., CHAN, C., RAMAKRISHNA, S., & MATSUURA, T. (2006). Electrospun nanofibrous filtration membrane. Journal of Membrane Science, 281(1-2), 581-586. doi:10.1016/j.memsci.2006.04.026Qin, X.-H., & Wang, S.-Y. (2006). Filtration properties of electrospinning nanofibers. Journal of Applied Polymer Science, 102(2), 1285-1290. doi:10.1002/app.24361Ren, G., Xu, X., Liu, Q., Cheng, J., Yuan, X., Wu, L., & Wan, Y. (2006). Electrospun poly(vinyl alcohol)/glucose oxidase biocomposite membranes for biosensor applications. Reactive and Functional Polymers, 66(12), 1559-1564. doi:10.1016/j.reactfunctpolym.2006.05.005Lee, S., & Obendorf, S. K. (2007). Use of Electrospun Nanofiber Web for Protective Textile Materials as Barriers to Liquid Penetration. Textile Research Journal, 77(9), 696-702. doi:10.1177/0040517507080284Heikkilä, P., Sipilä, A., Peltola, M., Harlin, A., & Taipale, A. (2007). Electrospun PA-66 Coating on Textile Surfaces. Textile Research Journal, 77(11), 864-870. doi:10.1177/0040517507078241Boudriot, U., Dersch, R., Greiner, A., & Wendorff, J. H. (2006). Electrospinning Approaches Toward Scaffold Engineering?A Brief Overview. Artificial Organs, 30(10), 785-792. doi:10.1111/j.1525-1594.2006.00301.xButtafoco, L., Kolkman, N. G., Engbers-Buijtenhuijs, P., Poot, A. A., Dijkstra, P. J., Vermes, I., & Feijen, J. (2006). Electrospinning of collagen and elastin for tissue engineering applications. Biomaterials, 27(5), 724-734. doi:10.1016/j.biomaterials.2005.06.024Lee, L. J. (2006). Polymer Nanoengineering for Biomedical Applications. Annals of Biomedical Engineering, 34(1), 75-88. doi:10.1007/s10439-005-9011-6Chew, S. Y., Hufnagel, T. C., Lim, C. T., & Leong, K. W. (2006). Mechanical properties of single electrospun drug-encapsulated nanofibres. Nanotechnology, 17(15), 3880-3891. doi:10.1088/0957-4484/17/15/045Huang, Z.-M., He, C.-L., Yang, A., Zhang, Y., Han, X.-J., Yin, J., & Wu, Q. (2006). Encapsulating drugs in biodegradable ultrafine fibers through co-axial electrospinning. Journal of Biomedical Materials Research Part A, 77A(1), 169-179. doi:10.1002/jbm.a.30564Kim, H.-W., Lee, H.-H., & Knowles, J. C. (2006). Electrospinning biomedical nanocomposite fibers of hydroxyapatite/poly(lactic acid) for bone regeneration. Journal of Biomedical Materials Research Part A, 79A(3), 643-649. doi:10.1002/jbm.a.30866Taepaiboon, P., Rungsardthong, U., & Supaphol, P. (2006). Drug-loaded electrospun mats of poly(vinyl alcohol) fibres and their release characteristics of four model drugs. Nanotechnology, 17(9), 2317-2329. doi:10.1088/0957-4484/17/9/041Ding, B., Kim, H.-Y., Lee, S.-C., Shao, C.-L., Lee, D.-R., Park, S.-J., … Choi, K.-J. (2002). Preparation and characterization of a nanoscale poly(vinyl alcohol) fiber aggregate produced by an electrospinning method. Journal of Polymer Science Part B: Polymer Physics, 40(13), 1261-1268. doi:10.1002/polb.10191Cui, W., Li, X., Zhou, S., & Weng, J. (2006). Investigation on process parameters of electrospinning system through orthogonal experimental design. Journal of Applied Polymer Science, 103(5), 3105-3112. doi:10.1002/app.25464Deitzel, J. ., Kleinmeyer, J., Harris, D., & Beck Tan, N. . (2001). The effect of processing variables on the morphology of electrospun nanofibers and textiles. Polymer, 42(1), 261-272. doi:10.1016/s0032-3861(00)00250-0Lyons, J., Li, C., & Ko, F. (2004). Melt-electrospinning part I: processing parameters and geometric properties. Polymer, 45(22), 7597-7603. doi:10.1016/j.polymer.2004.08.071Theron, S. A., Zussman, E., & Yarin, A. L. (2004). Experimental investigation of the governing parameters in the electrospinning of polymer solutions. Polymer, 45(6), 2017-2030. doi:10.1016/j.polymer.2004.01.024Kilic, A., Oruc, F., & Demir, A. (2008). Effects of Polarity on Electrospinning Process. Textile Research Journal, 78(6), 532-539. doi:10.1177/0040517507081296Reneker, D. H., & Chun, I. (1996). Nanometre diameter fibres of polymer, produced by electrospinning. Nanotechnology, 7(3), 216-223. doi:10.1088/0957-4484/7/3/009Lee, J. S., Choi, K. H., Ghim, H. D., Kim, S. S., Chun, D. H., Kim, H. Y., & Lyoo, W. S. (2004). Role of molecular weight of atactic poly(vinyl alcohol) (PVA) in the structure and properties of PVA nanofabric prepared by electrospinning. Journal of Applied Polymer Science, 93(4), 1638-1646. doi:10.1002/app.20602Mit-uppatham, C., Nithitanakul, M., & Supaphol, P. (2004). Effects of Solution Concentration, Emitting Electrode Polarity, Solvent Type, and Salt Addition on Electrospun Polyamide-6 Fibers: A Preliminary Report. Macromolecular Symposia, 216(1), 293-300. doi:10.1002/masy.200451227Kim, S. J., Lee, C. K., & Kim, S. I. (2005). Effect of ionic salts on the processing of poly(2-acrylamido-2-methyl-1-propane sulfonic acid) nanofibers. Journal of Applied Polymer Science, 96(4), 1388-1393. doi:10.1002/app.21567ZHANG, C., YUAN, X., WU, L., & SHENG, J. (2006). PROPERTIES OF ULTRAFINE FIBROUS POLY(VINYL ALCOHOL) MEMBRANES BY ELECTROSPINNING. Acta Polymerica Sinica, 006(2), 294-297. doi:10.3724/sp.j.1105.2006.00294Supaphol, P., & Chuangchote, S. (2008). On the electrospinning of poly(vinyl alcohol) nanofiber mats: A revisit. Journal of Applied Polymer Science, 108(2), 969-978. doi:10.1002/app.27664Jones, R. N. (1962). THE EFFECTS OF CHAIN LENGTH ON THE INFRARED SPECTRA OF FATTY ACIDS AND METHYL ESTERS. Canadian Journal of Chemistry, 40(2), 321-333. doi:10.1139/v62-050Yao, L., Haas, T. W., Guiseppi-Elie, A., Bowlin, G. L., Simpson, D. G., & Wnek, G. E. (2003). Electrospinning and Stabilization of Fully Hydrolyzed Poly(Vinyl Alcohol) Fibers. Chemistry of Materials, 15(9), 1860-1864. doi:10.1021/cm0210795Wei, Q. F., Gao, W. D., Hou, D. Y., & Wang, X. Q. (2005). Surface modification of polymer nanofibres by plasma treatment. 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A user-centered chatbot to identify and interconnect individual, social and environmental risk factors related to overweight and obesity

[EN] The objective of this study was to assess the feasibility of using a user-centered chatbotfor collecting linked data to study overweight and obesity causes ina target population. In total 980 people participated in the feasibility study organized in three studies: (1) within a group of university students (88 participants), (2) in a small town (422 participants), and (3) within a university community (470 participants). We gathered self-reported data through the Wakamola chatbot regarding participants diet, physical activity, social network, living area, obesity-associated diseases, and sociodemographic data. For each study, we calculated the mean Body Mass Index (BMI) and number of people in each BMI level. Also, we defined and calculated scores (1-100 scale) regarding global health, BMI, alimentation, physical activity and social network. Moreover, we graphically represented obesity risk for living areas and the social network with nodes colored by BMI. Students group results: Mean BMI 21.37 (SD 2.57) (normal weight), 8 people underweight, 5 overweight, 0 obesity, global health status 78.21, alimentation 63.64, physical activity 65.08 and social 26.54, 3 areas with mean BMI level of obesity, 17 with overweight level. Small town ' s study results: Mean BMI 25.66 (SD 4.29) (overweight), 2 people underweight, 63 overweight, 26 obesity, global health status 69.42, alimentation 64.60, physical activity 60.61 and social 1.14, 1 area with mean BMI in normal weight; University ' s study results: Mean BMI 23.63 (SD 3.7) (normal weight), 22 people underweight, 86 overweight, 28 obesity, global health status 81.03, alimentation 81.84, physical activity 70.01 and social 1.47, 3 areas in obesity level, 19 in overweight level. Wakamola is a health care chatbot useful to collect relevant data from populations in the risk of overweight and obesity. Besides, the chatbot provides individual self-assessment of BMI and general status regarding the style of living. Moreover, Wakamola connects users in a social network to help the study of O & O ' s causes from an individual, social and socio-economic perspective.Funding for this study was provided by the authors' various departments, and partially by the Crowd Health Project (Collective Wisdom Driving Public Health Policies [727560]).Asensio-Cuesta, S.; Blanes-Selva, V.; Conejero, JA.; Portolés, M.; Garcia-Gomez, JM. (2022). A user-centered chatbot to identify and interconnect individual, social and environmental risk factors related to overweight and obesity. Informatics for Health and Social Care. 47(1):38-52. https://doi.org/10.1080/17538157.2021.1923501385247

Forensic Science: Current State and Perspective by a Group of Early Career Researchers

© 2016, Springer Science+Business Media Dordrecht. Forensic science and its influence on policing and the criminal justice system have increased since the beginning of the twentieth century. While the philosophies of the forensic science pioneers remain the pillar of modern practice, rapid advances in technology and the underpinning sciences have seen an explosion in the number of disciplines and tools. Consequently, the way in which we exploit and interpret the remnant of criminal activity are adapting to this changing environment. In order to best exploit the trace, an interdisciplinary approach to both research and investigation is required. In this paper, nine postdoctoral research fellows from a multidisciplinary team discuss their vision for the future of forensic science at the crime scene, in the laboratory and beyond. This paper does not pretend to be exhaustive of all fields of forensic science, but describes a portion of the postdoctoral fellows’ interests and skills

Influence of glyoxal in the physical characterization of PVA nanofibres

[EN] The influence of solution composition is directly related to the properties of polyvinyl alcohol (PVA) nanofibers. Electrospinning is a viable technique to develop PVA nanofibers. The presence of a crosslinking agent such as glyoxal can produce variations not only in anti-water solubility effect, but also in the morphology of the electrodeposited fibers. The objective of this study was to characterize the influence of glyoxal on PVA nanofibers. Thus, we studied fiber dimensions, the weight of deposited fibers, and fiber crystallinity. The relation between those properties and the properties of the nanofiber web (color, opacity, and roughness) were studied. In this study we changed glyoxal concentration. Scanning electron microscopy, differential scanning calorimetry, and atomic force microscopy showed changes in the fiber properties. We could observe how the diameter fiber increased, the collector surface was widely covered, and the fiber crystallinity decreased. Regarding the properties of the web, the roughness decreased and the color turned whiter.The authors wish to acknowledge the financial support of the MINISTERIO DE CIENCIA E INNOVACION. Ref: CIT-020000-2008-016 for financial support. Also, the microscopy services at UPV are gratefully acknowledged for their assistance in using AFM techniques, and Octavio Fenollar at UPV is gratefully acknowledged for his assistance in using calorimetric techniques.Blanes, M.; Gisbert, MJ.; Marco, B.; Bonet Aracil, MA.; Gisbert Paya, J.; Balart Gimeno, RA. (2010). Influence of glyoxal in the physical characterization of PVA nanofibres. Textile Research Journal. 80(14):1465-1472. doi:10.1177/0040517509357654S14651472801

Aerosol Route to Antibacterial Nanosilver Coating of Cotton Fabrics

The paper describes a gas phase process for the preparation of cotton fabrics coated with silver nanoparticles as antimicrobial agents. Silver nanoparticles are synthesized by means of atmospheric pressure electrical discharges (spark discharge and glow discharge) in pure inert gases, and the aerosols are passed through cotton fabric samples, where nanoparticles deposit. The particle size distribution of the aerosols is measured online during synthesis. Also, the cristallinity, size and morphology of the silver particles are analyzed. The mean size of the primary particles of silver varies from 4 nm to 18 nm, depending upon the type of discharge, the nature and flow rate of the gas. The bactericidal activity of the cotton samples doped with silver nanoparticles is assessed following the ISO 20743 method. All cotton samples show significant bactericidal property, although it degrades with increasing primary particle size and particle agglomeration. This purely physical aerosol route is a promising sustainable method for nanocoating of textiles