1,799 research outputs found
Distributed Real-Time Computation of the Point of Gaze
This paper presents a minimally intrusive real-time gaze-tracking prototype to be used in several scenarios, including a laboratory stall and an in-vehicle system. The system requires specific infrared illumination to allow it to work with variable light conditions. However, it is minimally intrusive due to the use of a carefully configured switched infrared LED array. Although the perceived level of illumination generated by this array is high, it is achieved using low-emission infrared light beams. Accuracy is achieved through a precise estimate of the center of the user's pupil. To overcome inherent time restrictions while using low-cost processors, its main image-processing algorithm has been distributed over four main computing tasks. This structure not only enables good performance, but also simplifies the task of experimenting with alternative computationally-complex algorithms and with alternative tracking models based on locating both user eyes and several cameras to improve user mobility
Caffeinating the biofuels market:Effect of the processing conditions during the production of biofuels and high-value chemicals by hydrothermal treatment of residual coffee pulp
5 figures, 4 tables, supplementary information.-- © 2021. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The manufacturing of coffee, one of the most popular beverages globally, renders enormous amounts of by-products and wastes, which may trigger severe environmental issues if not treated appropriately. The coffee pulp, resulting from the wet processing of coffee, is the predominant by-product, with around 10 Mt annually produced worldwide. For the first time, this work addresses the hydrothermal treatment of coffee pulp to produce biofuels and platform molecules, scrutinising the influence of the processing conditions (temperature, pressure, reaction time and solid/water ratio) on the process. This strategy allowed the transformation of coffee pulp into bio-crude and hydrochar in different yields (10–26% and 10–42%, respectively), depending on the conditions. The bio-crude included a pool of alkanes, carboxylic acids, ketones, phenols and nitrogen species, with varying quantities of C (54–71 wt%), H (6–7 wt%), O (18–34 wt%) and N (3–5 wt%) and a calorific value shifting from 23 to 32 MJ/kg. The hydrochar contained different proportions of C (57–72 wt%), H (4–6 wt%), O (20–35 wt%) and N (2–3 wt%) and had a calorific value between 22 and 29 MJ/kg. Process optimisation showed that up to 45% of the coffee pulp could be simultaneously converted into energy-rich (29 MJ/kg), merchantable liquid (20% bio-crude) and solid (24% hydrochar) biofuels during the treatment of a 15 wt% coffee pulp suspension at 320 °C and 162 bar for 1 h. At the same time, a bio-crude with a high proportion of profitable phenolic derivatives (42%) can be attained in high yield (25%) when a 5 wt% suspension is treated at 280 °C and 120 bar for 2 h. These promising results, along with the bespoke nature of this hydrothermal treatment, are a landmark achievement for the economy and sustainability of coffee producer countries, thus representing a pioneering step change towards the sustainable management of early-stage coffee leftovers.The authors wish to express their gratefulness to FEDER, the Spanish Ministry of Science, Innovation and Universities (Grant Number ENE2017-83854-R) and the Spanish National Research Council (CSIC) (Grant Number COOPA20367) for providing financial support. Besides, Javier Remón is very grateful to the Spanish Ministry of Science, Innovation and Universities for the Juan de la Cierva (JdC) fellowships (Grant Numbers FJCI-2016-30847 and IJC2018-037110-I) awarded. Lorena Pedraza-Segura and Pedro Arcelus-Arrillaga would like to acknowledge the financial support of INIAT and DINV at Universidad Iberoamericana for their research.Peer reviewe
Glacial geomorphology of the High Gredos Massif: Gredos and Pinar valleys (Iberian Central System, Spain)
We present a detailed geomorphological map of the landform assemblages originated by the two major paleoglaciers of the Sierra de Gredos mountain range in the Spanish Iberian Central System. Based on previous works, our map focused on the features formed by Gredos and Pinar paleoglaciers during the last glaciation and subsequent glacial events. Based on a remote sensing analysis and exhaustive field surveys, we identified with great accuracy the local distribution of glacial, periglacial, mass movement, structural, fluvial, and lacustrine features. We recognized three main glacial geomorphological formations representing: (i) the maximum glacial extension reached (peripheral deposits); (ii) the culmination of glacial conditions (principal moraines) and (iii) the local glacial withdrawal (internal deposits). Our map offers a renewed spatial framework on which to conduct higher-resolution glacial chronologies, especially of Late Glacial and Holocene glacial activity, providing key information for performing future paleoclimatic reconstructions of the northern hemisphere mid-latitudes
Garlic's ability to prevent in vitro Cu(2+)-induced lipoprotein oxidation in human serum is preserved in heated garlic: effect unrelated to Cu(2+)-chelation
BACKGROUND: It has been shown that several extracts and compounds derived from garlic are able to inhibit Cu(2+)-induced low density lipoprotein oxidation. In this work we explored if the ability of aqueous garlic extract to prevent in vitro Cu(2+)-induced lipoprotein oxidation in human serum is affected by heating (a) aqueous garlic extracts or (b) garlic cloves. In the first case, aqueous extract of raw garlic and garlic powder were studied. In the second case, aqueous extract of boiled garlic cloves, microwave-treated garlic cloves, and pickled garlic were studied. It was also studied if the above mentioned preparations were able to chelate Cu(2+). METHODS: Cu(2+)-induced lipoprotein oxidation in human serum was followed by the formation of conjugated dienes at 234 nm and 37°C by 240 min in a phosphate buffer 20 mM, pH 7.4. Blood serum and CuSO(4 )were added to a final concentration of 0.67% and 0.0125 mM, respectively. The lag time and the area under the curve from the oxidation curves were obtained. The Cu(2+)-chelating properties of garlic extracts were assessed using an approach based upon restoring the activity of xanthine oxidase inhibited in the presence of 0.050 mM Cu(2+). The activity of xanthine oxidase was assessed by monitoring the production of superoxide anion at 560 nm and the formation of uric acid at 295 nm. Data were compared by parametric or non-parametric analysis of variance followed by a post hoc test. RESULTS: Extracts from garlic powder and raw garlic inhibited in a dose-dependent way Cu(2+)-induced lipoprotein oxidation. The heating of garlic extracts or garlic cloves was unable to alter significantly the increase in lag time and the decrease in the area under the curve observed with the unheated garlic extracts or raw garlic. In addition, it was found that the garlic extracts were unable to chelate Cu(2+). CONCLUSIONS: (a) the heating of aqueous extracts of raw garlic or garlic powder or the heating of garlic cloves by boiling, microwave or pickling do not affect garlic's ability to inhibit Cu(2+)-induced lipoprotein oxidation in human serum, and (b) this ability is not secondary to Cu(2+)-chelation
S-allylmercaptocysteine scavenges hydroxyl radical and singlet oxygen in vitro and attenuates gentamicin-induced oxidative and nitrosative stress and renal damage in vivo
BACKGROUND: Oxidative and nitrosative stress have been involved in gentamicin-induced nephrotoxicity. The purpose of this work was to study the effect of S-allylmercaptocysteine, a garlic derived compound, on gentamicin-induced oxidative and nitrosative stress and nephrotoxicity. In addition, the in vitro reactive oxygen species scavenging properties of S-allylmercaptocysteine were studied. RESULTS: S-allylmercaptocysteine was able to scavenge hydroxyl radicals and singlet oxygen in vitro. In rats treated with gentamicin (70 mg/Kg body weight, subcutaneously, every 12 h, for 4 days), renal oxidative stress was made evident by the increase in protein carbonyl content and 4-hydroxy-2-nonenal, and the nitrosative stress was made evident by the increase in 3-nitrotyrosine. In addition, gentamicin-induced nephrotoxicity was evident by the: (1) decrease in creatinine clearance and in activity of circulating glutathione peroxidase, and (2) increase in urinary excretion of N-acetyl-β-D-glucosaminidase, and (3) necrosis of proximal tubular cells. Gentamicin-induced oxidative and nitrosative stress and nephrotoxicity were attenuated by S-allylmercaptocysteine treatment (100 mg/Kg body weight, intragastrically, 24 h before the first dose of gentamicin and 50 mg/Kg body weight, intragastrically, every 12 h, for 4 days along gentamicin-treatment). CONCLUSION: In conclusion, S-allylmercaptocysteine is able to scavenge hydroxyl radicals and singlet oxygen in vitro and to ameliorate the gentamicin-induced nephrotoxicity and oxidative and nitrosative stress in vivo
Multicore and FPGA implementations of emotional-based agent architectures
The final publication is available at Springer via http://dx.doi.org/10.1007/s11227-014-1307-6.Control architectures based on Emotions are becoming promising solutions for the implementation of future robotic agents. The basic controllers of the architecture are the emotional processes that decide which behaviors of the robot must activate to fulfill the objectives. The number of emotional processes increases (hundreds of millions/s) with the complexity level of the application, reducing the processing capacity of the main processor to solve complex problems (millions of decisions in a given instant). However, the potential parallelism of the emotional processes permits their execution in parallel on FPGAs or Multicores, thus enabling slack computing in the main processor to tackle more complex dynamic problems. In this paper, an emotional architecture for mobile robotic agents is presented. The workload of the emotional processes is evaluated. Then, the main processor is extended with FPGA co-processors through Ethernet link. The FPGAs will be in charge of the execution of the emotional processes in parallel. Different Stratix FPGAs are compared to analyze their suitability to cope with the proposed mobile robotic agent applications. The applications are set up taking into account different environmental conditions, robot dynamics and emotional states. Moreover, the applications are run also on Multicore processors to compare their performance in relation to the FPGAs. Experimental results show that Stratix IV FPGA increases the performance in about one order of magnitude over the main processor and solves all the considered problems. Quad-Core increases the performance in 3.64 times, allowing to tackle about 89 % of the considered problems. Quad-Core has a lower cost than a Stratix IV, so more adequate solution but not for the most complex application. Stratix III could be applied to solve problems with around the double of the requirements that the main processor could support. Finally, a Dual-Core provides slightly better performance than stratix III and it is relatively cheaper.This work was supported in part under Spanish Grant PAID/2012/325 of "Programa de Apoyo a la Investigacion y Desarrollo. Proyectos multidisciplinares", Universitat Politecnica de Valencia, Spain.Domínguez Montagud, CP.; Hassan Mohamed, H.; Crespo, A.; Albaladejo Meroño, J. (2015). Multicore and FPGA implementations of emotional-based agent architectures. Journal of Supercomputing. 71(2):479-507. https://doi.org/10.1007/s11227-014-1307-6S479507712Malfaz M, Salichs MA (2010) Using MUDs as an experimental platform for testing a decision making system for self-motivated autonomous agents. Artif Intell Simul Behav J 2(1):21–44Damiano L, Cañamero L (2010) Constructing emotions. Epistemological groundings and applications in robotics for a synthetic approach to emotions. In: Proceedings of international symposium on aI-inspired biology, The Society for the Study of Artificial Intelligence, pp 20–28Hawes N, Wyatt J, Sloman A (2009) Exploring design space for an integrated intelligent system. Knowl Based Syst 22(7):509–515Sloman A (2009) Some requirements for human-like robots: why the recent over-emphasis on embodiment has held up progress. Creat Brain Like Intell 2009:248–277Arkin RC, Ulam P, Wagner AR (2012) Moral decision-making in autonomous systems: enforcement, moral emotions, dignity, trust and deception. In: Proceedings of the IEEE, Mar 2012, vol 100, no 3, pp 571–589iRobot industrial robots website. http://www.irobot.com/gi/ground/ . Accessed 22 Sept 2014Moravec H (2009) Rise of the robots: the future of artificial intelligence. Scientific American, March 2009. http://www.scientificamerican.com/article/rise-of-the-robots/ . 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Comput J 54(8):1282–1294Del Campo I, Basterretxea K, Echanobe J, Bosque G, Doctor F (2012) A system-on-chip development of a neuro-fuzzy embedded agent for ambient-intelligence environments. IEEE Trans Syst Man Cybern Part B 42(2):501–512Pedraza C, Castillo J, Martínez JI, Huerta P, Bosque JL, Cano J (2011) Genetic algorithm for Boolean minimization in an FPGA cluster. J Supercomput 58(2):244–252Orlowska-Kowalska T, Kaminski M (2011) FPGA implementation of the multilayer neural network for the speed estimation of the two-mass drive system. IEEE Trans Ind Inf 7(3):436–445Cassidy AS, Merolla P, Arthur JV, Esser SK, Jackson B, Alvarez-icaza R, Datta P, Sawada J, Wong TM, Feldman V, Amir A, Ben-dayan D, Mcquinn E, Risk WP, Modha DS (2013) Cognitive computing building block: a versatile and efficient digital neuron model for neurosynaptic cores. In: Proceedings of international joint conference on neural networks, IEEE (IJCNN’2013)IBM Cognitive Computing and Neurosynaptic chips website. http://www.research.ibm.com/cognitive-computing/neurosynaptic-chips.shtml . Accessed 22 Sept 2014Seo E, Jeong J, Park S, Lee J (2008) Energy efficient scheduling of real-time tasks on multicore processors. IEEE Trans Parallel Distrib Syst 19(11):1540–1552Lehoczky J, Sha L, Ding Y (1989) The rate monotonic scheduling algorithm: exact characterization and average case behavior. In: Proceedings of real time systems symposium, IEEE 1989, pp 166–171Ng-Thow-Hing V, Lim J, Wormer J, Sarvadevabhatla RK, Rocha C, Fujimura K, Sakagami Y (2008) The memory game: creating a human-robot interactive scenario for ASIMO. In: Proceedings of intelligent robots and systems, 2008, IROS 2008, IEEE/RSJ international conference, pp 779–78
Mercury alloy for secondary gold ores extraction in Roman times. Fact or fiction?
Una de las mayores controversias que suscita el estudio geoarqueológico de la minería aurífera romana se refiere al empleo de la
amalgama con mercurio (Hg) para la concentración de oro en yacimientos tipo placer, donde éste aparece libre, en forma de pequeñas
partículas o pepitas que se acumulan en el sedimento aurífero. A
pesar de que el uso y propiedades del mercurio fueron conocidas
en época romana, son escasos los trabajos realizados que permiten
establecer las condiciones en las que su empleo estaba justificado
en la recuperación y beneficio del oro procedente de yacimientos secundarios. En este artículo se ha realizado un estudio geoquímico de
suelos para establecer su empleabilidad en la recuperación de oro
en este tipo de explotaciones. Para ello, se ha analizado la concentración de Hg en los tramos de canal de lavado (agogae), donde se
realizaría la extracción de oro. Los resultados indican que las anomalías observadas están ligadas al acopio y su posterior uso, ya que
se concentran en los tramos inferiores de los canales. Esto confirma
el empleo de mercurio para el beneficio aurífero en yacimientos de
tipo placer, arrojando luz sobre los métodos metalúrgicos empleados en época romanaOne of the major controversies in the geo-archaeological study
of Roman gold mining concerns the use of mercury (Hg) amalgamation for gold concentration in placer-type deposits, where appears as
native gold, in the form of small particles or nuggets that accumulate
in the sediment. Despite the use and properties of Hg were known in
Roman times, few studies have been focused on the conditions under which its use was justified in the recovery of gold from placer deposits. In this article a soil geochemical study has been conducted to
confirm its use in the gold recovery process within this type of exploitations. To this end, the concentration of Hg was analyzed in sections
of the washing channel (agogae), where the gold was extracted. The
results indicate that Hg anomalies are associated with the collection
and subsequent use of mercury, since they are concentrated in the
lower sectors of the mine. This suggests the use of Hg for gold mining
recovery in placer ore deposits, shedding light into the metallurgical
methods used in Roman time
Search for pairs of highly collimated photon-jets in pp collisions at s =13 TeV with the ATLAS detector
Results of a search for the pair production of photon-jets - collimated groupings of photons - in the ATLAS detector at the Large Hadron Collider are reported. Highly collimated photon-jets can arise from the decay of new, highly boosted particles that can decay to multiple photons collimated enough to be identified in the electromagnetic calorimeter as a single, photonlike energy cluster. Data from proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 36.7 fb-1, were collected in 2015 and 2016. Candidate photon-jet pair production events are selected from those containing two reconstructed photons using a set of identification criteria much less stringent than that typically used for the selection of photons, with additional criteria applied to provide improved sensitivity to photon-jets. Narrow excesses in the reconstructed diphoton mass spectra are searched for. The observed mass spectra are consistent with the Standard Model background expectation. The results are interpreted in the context of a model containing a new, high-mass scalar particle with narrow width, X, that decays into pairs of photon-jets via new, light particles, a. Upper limits are placed on the cross section times the product of branching ratios σ×B(X→aa)×B(a→γγ)2 for 200 GeV<mX<2 TeV and for ranges of ma from a lower mass of 100 MeV up to between 2 and 10 GeV, depending upon mX. Upper limits are also placed on σ×B(X→aa)×B(a→3π0)2 for the same range of mX and for ranges of ma from a lower mass of 500 MeV up to between 2 and 10 GeV.Peer Reviewe
Evaluation of machine learning algorithms and structural features for optimal MRI-based diagnostic prediction in psychosis
A relatively large number of studies have investigated the power of structural magnetic resonance imaging (sMRI) data to discriminate patients with schizophrenia from healthy controls. However, very few of them have also included patients with bipolar disorder, allowing the clinically relevant discrimination between both psychotic diagnostics. To assess the efficacy of sMRI data for diagnostic prediction in psychosis we objectively evaluated the discriminative power of a wide range of commonly used machine learning algorithms (ridge, lasso, elastic net and L0 norm regularized logistic regressions, a support vector classifier, regularized discriminant analysis, random forests and a Gaussian process classifier) on main sMRI features including grey and white matter voxel-based morphometry (VBM), vertex-based cortical thickness and volume, region of interest volumetric measures and wavelet-based morphometry (WBM) maps. All possible combinations of algorithms and data features were considered in pairwise classifications of matched samples of healthy controls (N = 127), patients with schizophrenia (N = 128) and patients with bipolar disorder (N = 128). Results show that the selection of feature type is important, with grey matter VBM (without data reduction) delivering the best diagnostic prediction rates (averaging over classifiers: schizophrenia vs. healthy 75%, bipolar disorder vs. healthy 63% and schizophrenia vs. bipolar disorder 62%) whereas algorithms usually yielded very similar results. Indeed, those grey matter VBM accuracy rates were not even improved by combining all feature types in a single prediction model. Further multi-class classifications considering the three groups simultaneously made evident a lack of predictive power for the bipolar group, probably due to its intermediate anatomical features, located between those observed in healthy controls and those found in patients with schizophrenia. Finally, we provide MRIPredict (https://www.nitrc.org/projects/mripredict/), a free tool for SPM, FSL and R, to easily carry out voxelwise predictions based on VBM images
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 8 TeV pp collisions with the ATLAS detector
Aad, G. et al.A search for the direct production of charginos and neutralinos in final states with three leptons and missing transverse momentum is presented. The analysis is based on 20.3 fb−1 of s√ = 8 TeV proton-proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with the Standard Model expectations and limits are set in R-parity-conserving phenomenological Minimal Supersymmetric Standard Models and in simplified supersymmetric models, significantly extending previous results. For simplified supersymmetric models of direct chargino (χ˜±1) and next-to-lightest neutralino (χ˜02) production with decays to lightest neutralino (χ˜01) via either all three generations of sleptons, staus only, gauge bosons, or Higgs bosons, (χ˜±1) and (χ˜02) masses are excluded up to 700 GeV, 380 GeV, 345 GeV, or 148 GeV respectively, for a massless (χ˜01).We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWF and FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; CONICYT, Chile; CAS, MOST and NSFC, China; COLCIENCIAS, Colombia; MSMT CR, MPO CR and VSC CR, Czech Republic; DNRF, DNSRC and Lundbeck Foundation, Denmark; EPLANET, ERC and NSRF, European Union; IN2P3-CNRS, CEA-DSM/IRFU, France; GNSF, Georgia; BMBF, DFG, HGF, MPG and AvH Foundation, Germany; GSRT and NSRF, Greece; ISF, MINERVA, GIF, I-CORE and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; FOM and NWO, Netherlands; BRF and RCN, Norway; MNiSW and NCN, Poland; GRICES and FCT, Portugal; MNE/IFA, Romania; MES of Russia and ROSATOM, Russian Federation; JINR; MSTD, Serbia; MSSR, Slovakia; ARRS and MIZˇS, Slovenia; DST/NRF, South Africa; MINECO, Spain; SRC and Wallenberg Foundation, Sweden; SER, SNSF and Cantons of Bern and Geneva, Switzerland; NSC, Taiwan; TAEK, Turkey.Peer reviewe
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