Design of an analog/digital truly random number generator

An analog-digital system is presented for the generation of truly random (aperiodic) digital sequences. This model is based on a very simple piecewise-linear discrete map which is suitable for implementation using monolithic analog sampled-data techniques. Simulation results are given illustrating the optimum choice of the model parameters. Circuit implementations are reported for the discrete map using both switched-capacitor (SC) and switched-current (SI) techniques. The layout of a SI prototype in a 3-μm n-well double-polysilicon double-metal technology is included

On the nature of motivational orientations: implications of assessed goals and gender differences for motivational goal theory

In a historical revision of the achievement goal construct, Elliot (2005) recognized that there is little consensus on whether the term “goal” in “achievement goal orientations” (GO) is best represented as an “aim”, as an overarching orientation encompassing several “aims”, or as a combination of aims and other processes -self-regulation, etc.-. Elliot pointed also that goal theory research provides evidence for different models of GO. As there were no consensus on these issues, we decided to get evidence about the nature and structure of GO, about the role of gender differences in the configuration of such structure, and about relations between GO, expectancies, volitional processes and achievement. A total of 382 university students from different faculties of two public universities of Madrid (Spain) that voluntarily accepted to fill in a questionnaire that assessed different goals, expectancies and self-regulatory processes participated in the study. Scales reliability, confirmatory factor analyses, multiple-group analyses, and correlation and regression analyses were carried out. Results support the trichotomous model of GO, the consideration of GO as a combination of aims and other psychological processes, showed some gender differences and favour the adoption of a multiple goal perspective for explaining students’ motivationThis research was supported by the grant of the Spanish Ministry of Science and Innovation, SEJ2005-0099

Nonlinear time-domain macromodeling of OTA circuits

The authors present an accurate nonlinear macromodel of the operational transconductance amplifier (OTA) which is suitable for the transient simulation of OTA-based CMOS analog integrated circuits. As compared to device-level OTA models, the proposed macromodel is advantageous in terms of CPU time. Also, in circuits with many OTAs, it does not have the problems of convergence that the device-level MODEL has. All the macromodel parameters can be calculated from measurements made at the OTA terminals. Experimental results from a 3-μm CMOS OTA prototype as well as simulation results from device-level models are included and compared to simulation results from the macromodel

Effects of nitrate contamination and seasonal variation on the denitrification and greenhouse gas production in La Rocina stream (Doñana National Park, SW Spain)

Climatic influence (global warming and decreased rainfall) could lead to an increase in the ecological and toxicological effects of the pollution in aquatic ecosystems, especially contamination from agricultural nitrate (NO3 −) fertilizers. Physicochemical properties of the surface waters and sediments of four selected sites varying in NO3 − concentration along La Rocina Stream, which feeds Marisma del Rocio in Do˜nana National Park (South West, Spain), were studied. Electrical conductivity, pH, content in macro and microelements, total organic carbon and nitrogen, and dissolved carbon and nitrogen were affected by each sampling site and sampling time. Contaminant NO3 − in surface water at the site with the highest NO3 − concentration (ranged in 61.6–106.6mgL−1) was of inorganic origin, most probably from chemical fertilizers, as determined chemically (90% of the total dissolved nitrogen from NO3 −) and by isotopic analysis of ı15N-NO3 −. Changes in seasonal weather conditions and hydrological effects at the sampling sites were also responsible for variations in some biological activities (dehydrogenase, -glucosidase, arylsulphatase, acid phosphatase and urease) in sediments, as well as in the production of the greenhouse gases CO2, CH4 and N2O. Both organic matter and NO3 − contents influenced rates of gas production. Increased NO3 − concentration also resulted in enhanced levels of potential denitrification measured as N2O production. The denitrification process was affected by NO3 − contamination and the rainfall regimen, increasing the greenhouse gases emissions (CO2, CH4 and especially N2O) during the driest season in all sampling sites studied.This work was supported by grants CGL2006-06870 and CTM2009-1473-C02-02 from Ministerio de Ciencia e Innovación (Spain) and RNM-4746 from Consejería de Innovación, Ciencia y Empresa de la Junta de Andalucía (Spain), all of them co-financed by the European Regional Development Fund (ERDF). Support of Junta de Andalucía to Research Group BIO-275 is also acknowledged. D. David Correa thanks Ministerio de Educación for predoctoral grant AP2007-03967.Peer reviewe

CVD-MET: an image difference metric designed for analysis of color vision deficiency aids

Color vision deficiency (CVD) has gained in relevance in the last decade, with a surge of proposals for aid systems that aim to improve the color discrimination capabilities of CVD subjects. This paper focuses on the proposal of a new metric called CVD-MET, that can evaluate the efficiency and naturalness of these systems through a set of images using a simulation of the subject’s vision. In the simulation, the effect of chromatic adaptation is introduced via CIECAM02, which is relevant for the evaluation of passive aids (color filters). To demonstrate the potential of the CVD-MET, an evaluation of a representative set of passive and active aids is carried out both with conventional image quality metrics and with CVD-MET. The results suggest that the active aids (recoloration algorithms) are in general more efficient and produce more natural images, although the changes that are introduced do not shift the CVD’s perception of the scene towards the normal observer’s perception.Junta de Andalucia A-TIC-050-UGR18Spanish Government FIS2017-89258-PMinisterio de Ciencia, Innovación y Universidades RTI2018-094738-B-I0

A Methodology for Evaluating the Robustness of Anomaly Detectors to Adversarial Attacks in Industrial Scenarios

Anomaly Detection systems based on Machine and Deep learning are the most promising solutions to detect cyberattacks in the industry. However, these techniques are vulnerable to adversarial attacks that downgrade prediction performance. Several techniques have been proposed to measure the robustness of Anomaly Detection in the literature. However, they do not consider that, although a small perturbation in an anomalous sample belonging to an attack, i.e., Denial of Service, could cause it to be misclassified as normal while retaining its ability to damage, an excessive perturbation might also transform it into a truly normal sample, with no real impact on the industrial system. This paper presents a methodology to calculate the robustness of Anomaly Detection models in industrial scenarios. The methodology comprises four steps and uses a set of additional models called support models to determine if an adversarial sample remains anomalous. We carried out the validation using the Tennessee Eastman process, a simulated testbed of a chemical process. In such a scenario, we applied the methodology to both a Long-Short Term Memory (LSTM) neural network and 1-dimensional Convolutional Neural Network (1D-CNN) focused on detecting anomalies produced by different cyberattacks. The experiments showed that 1D-CNN is significantly more robust than LSTM for our testbed. Specifically, a perturbation of 60% (empirical robustness of 0.6) of the original sample is needed to generate adversarial samples for LSTM, whereas in 1D-CNN the perturbation required increases up to 111% (empirical robustness of 1.11)

Usefulness of manufactured tomato extracts in the diagnosis of tomato sensitization: Comparison with the prick-prick method

<p>Abstract</p> <p>Background</p> <p>Commercial available skin prick test with fruits can be negative in sensitized or allergic patients due to a reduction in biological activity during the manufacturing process. Prick-prick tests with fresh foods are often preferred, but they are a non-standardized procedure. The usefulness of freeze-dried extracts of Canary Islands tomatoes, comparing the wheal sizes induced by prick test with the prick-prick method in the diagnosis of tomato sensitization has been analyzed.</p> <p>The objective of the study was to assess the potential diagnostic of freeze-dried extracts of Canary Islands tomatoes, comparing the wheal sizes induced by prick test with the prick-prick method.</p> <p>Methods</p> <p>Two groups of patients were analyzed: Group I: 26 individuals reporting clinical symptoms induced by tomato contact or ingestion. Group II: 71 control individuals with no symptoms induced by tomato: 12 of them were previously skin prick test positive to a tomato extract, 39 were atopic and 20 were non-atopic. All individuals underwent prick-prick with fresh ripe peel Canary tomatoes and skin prick tested with freeze-dried peel and pulp extracts obtained from peel and pulp of Canary tomatoes at 10 mg/ml. Wheal sizes and prick test positivity (≥ 7 mm²) were compared between groups.</p> <p>Results</p> <p>In group I, 21 (81%) out of 26 patients were prick-prick positive. Twenty patients (77%) had positive skin prick test to peel extracts and 12 (46%) to pulp extracts. Prick-prick induced a mean wheal size of 43.81 ± 40.19 mm²compared with 44.25 ± 36.68 mm²induced by the peel extract (Not significant), and 17.79 ± 9.39 mm²induced by the pulp extract (p < 0.01).</p> <p>In group II, 13 (18%) out of 71 control patients were prick-prick positive. Twelve patients (all of them previously positive to peel extract) had positive skin prick test to peel and 3 to pulp. Prick-prick induced a mean wheal size of 28.88 ± 13.12 mm²compared with 33.17 ± 17.55 mm²induced by peel extract (Not significant), and 13.33 ± 4.80 mm²induced by pulp extract (p < 0.05 with peel extract and prick-prick).</p> <p>Conclusion</p> <p>Canary peel tomato extract seems to be as efficient as prick-prick tests with ripe tomatoes to diagnose patients sensitized to tomato. The wheal sizes induced by prick-prick and peel extracts were very similar and showed a high correlation coefficient.</p

The Last Interglacial from a continental area in Western Mediterranean. The Fuentillejo maar lacustrine record, Central Spain

The Fuentillejo maar is located in the Central Spanish Volcanic Field of Campo de Calatrava. Fuentillejo maar-lake has been a closed system and contains over 142 m of lacustrine sediments (Martín-Serrano et al., 2009). Geochemical (element analysis, molecular analysis of organic compounds), physical, palynological, stable isotope analysis, mineralogical and sedimentan/ facies analysis were performed to characterize the sedimentan/ record in the 57-59.3 m depth interval of core FUENT-1. These proxies reconstruct the paleoenvironmental and paleoclimatic processes which controlled vegetation patterns, lake water level and deposition of sedimentan/ facies occurred during the Last Interglacial period

Levodopa-Induced Dyskinesia in Parkinson Disease Specifically Associates with Dopaminergic Depletion in Sensorimotor-Related Functional Subregions of the Striatum

[Purpose] To determine whether the development of levodopa-induced dyskinesia (LID) in Parkinson disease (PD) specifically relates to dopaminergic depletion in sensorimotor-related subregions of the striatum.[Methods] Our primary study sample consisted of 185 locally recruited PD patients, of which 73 (40%) developed LID. Retrospective 123I-FP-CIT SPECT data were used to quantify the specific dopamine transporter (DAT) binding ratio within distinct functionally defined striatal subregions related to limbic, executive, and sensorimotor systems. Regional DAT levels were contrasted between patients who developed LID (PD + LID) and those who did not (PD-LID) using analysis of covariance models controlled for demographic and clinical features. For validation of the findings and assessment of the evolution of LID-associated DAT changes from an early disease stage, we also studied serial 123I-FP-CIT SPECT data from 343 de novo PD patients enrolled in the Parkinson Progression Marker’s Initiative using mixed linear model analysis.[Results] Compared with PD-LID, DAT level reductions in PD + LID patients were most pronounced in the sensorimotor striatal subregion (F = 5.99, P = 0.016) and also significant in the executive-related subregion (F = 5.30, P = 0.023). In the Parkinson Progression Marker’s Initiative cohort, DAT levels in PD + LID (n = 161, 47%) were only significantly reduced compared with PD-LID in the sensorimotor striatal subregion (t = −2.05, P = 0.041), and this difference was already present at baseline and remained largely constant over time.[Conclusion] Measuring DAT depletion in functionally defined sensorimotor-related striatal regions of interest may provide a more sensitive tool to detect LID-associated dopaminergic changes at an early disease stage and could improve individual prognosis of this common clinical complication in PD.Peer reviewe