2,332 research outputs found
A low-power integrated smart sensor with on-chip real-time image processing capabilities
A low-power, CMOS retina with real-time, pixel-level processing capabilities is presented. Features extraction and edge-enhancement are implemented with fully programmable 1D Gabor convolutions. An equivalent computation rate of 3 GOPS is obtained at the cost of very low-power consumption ( W per pixel), providing real-time performances ( microseconds for overall computation, ). Experimental results from the first realized prototype show a very good matching between measures and expected outputs
Non-rectangular neurostimulation waveforms elicit varied sensation quality and perceptive fields on the hand
Electrical stimulation of the nerves is known to elicit distinct sensations perceived in distal parts of the body. The stimulation is typically modulated in current with charge-balanced rectangular shapes that, although easily generated by stimulators available on the market, are not able to cover the entire range of somatosensory experiences from daily life. In this regard, we have investigated the effect of electrical neurostimulation with four non-rectangular waveforms in an experiment involving 11 healthy able-bodied subjects. Weiss curves were estimated and rheobase and chronaxie values were obtained showing increases in stimulation time required to elicit sensations for some waveforms. The localization of the sensations reported in the hand also appeared to differ between waveforms, although the total area did not vary significantly. Finally, the possibility of distinguishing different charge- and amplitude-matched stimuli was demonstrated through a two-alternative-forced-choice (2AFC) match-to-sample task, showing the ability of participants to successfully distinguish between waveforms with similar electrical characteristics but different shapes and charge transfer rates. This study provides evidence that, by using different waveforms to stimulate nerves, it is possible to affect not only the required charge to elicit sensations but also the sensation\ua0quality and its localization
The first ASIC prototype of a 28 nm time-space front-end electronics for real-time tracking
A front-end ASIC for 4D tracking is presented. The prototype includes the block necessary to build a pixel front-end chain for timing measurement, as independent circuits. The architecture includes a charge-sensitive amplifier, a discriminator with programmable threshold, and a time- to-digital converter. The blocks were designed with target specifications in mind including: an area occupation of 55 ÎĽm Ă— 55 ÎĽm, a power consumption tens of micro ampere per channel and timing a resolution of at least 100 ps. The prototype has been designed and integrated in 28 nm CMOS technology. The presented design is part of the TimeSpOT project which aims to reach a high-resolution particle tracking both in space and in time, in order to provide front-end circuitry suitable for next generation colliders
Predicting the occurrence of embolic events: an analysis of 1456 episodes of infective endocarditis from the Italian Study on Endocarditis (SEI)
Background: Embolic events are a major cause of morbidity and mortality in patients with infective endocarditis. We analyzed the database of the prospective cohort study SEI in order to identify factors associated with the occurrence of embolic events and to develop a scoring system for the assessment of the risk of embolism. Methods: We retrospectively analyzed 1456 episodes of infective endocarditis from the multicenter study SEI. Predictors of embolism were identified. Risk factors identified at multivariate analysis as predictive of embolism in left-sided endocarditis, were used for the development of a risk score: 1 point was assigned to each risk factor (total risk score range: minimum 0 points; maximum 2 points). Three categories were defined by the score: low (0 points), intermediate (1 point), or high risk (2 points); the probability of embolic events per risk category was calculated for each day on treatment (day 0 through day 30).Results: There were 499 episodes of infective endocarditis (34%) that were complicated by 65 1 embolic event. Most embolic events occurred early in the clinical course (first week of therapy: 15.5 episodes per 1000 patient days; second week: 3.7 episodes per 1000 patient days). In the total cohort, the factors associated with the occurrence of embolism at multivariate analysis were prosthetic valve localization (odds ratio, 1.84), right-sided endocarditis (odds ratio, 3.93), Staphylococcus aureus etiology (odds ratio, 2.23) and vegetation size 65 13 mm (odds ratio, 1.86). In left-sided endocarditis, Staphylococcus aureus etiology (odds ratio, 2.1) and vegetation size 65 13 mm (odds ratio, 2.1) were independently associated with embolic events; the 30-day cumulative incidence of embolism varied with risk score category (low risk, 12%; intermediate risk, 25%; high risk, 38%; p < 0.001).Conclusions: Staphylococcus aureus etiology and vegetation size are associated with an increased risk of embolism. In left-sided endocarditis, a simple scoring system, which combines etiology and vegetation size with time on antimicrobials, might contribute to a better assessment of the risk of embolism, and to a more individualized analysis of indications and contraindications for early surgery
Antarctic ozone hole modifies iodine geochemistry on the Antarctic Plateau
Polar stratospheric ozone has decreased since the 1970s due to anthropogenic emissions of chlorofluorocarbons and halons, resulting in the formation of an ozone hole over Antarctica. The effects of the ozone hole and the associated increase in incoming UV radiation on terrestrial and marine ecosystems are well established; however, the impact on geochemical cycles of ice photoactive elements, such as iodine, remains mostly unexplored. Here, we present the first iodine record from the inner Antarctic Plateau (Dome C) that covers approximately the last 212 years (1800-2012 CE). Our results show that the iodine concentration in ice remained constant during the pre-ozone hole period (1800-1974 CE) but has declined twofold since the onset of the ozone hole era (~1975 CE), closely tracking the total ozone evolution over Antarctica. Based on ice core observations, laboratory measurements and chemistry-climate model simulations, we propose that the iodine decrease since ~1975 is caused by enhanced iodine re-emission from snowpack due to the ozone hole-driven increase in UV radiation reaching the Antarctic Plateau. These findings suggest the potential for ice core iodine records from the inner Antarctic Plateau to be as an archive for past stratospheric ozone trends.Fil: Spolaor, Andrea. Consiglio Nazionale Delle Ricerche. Istituto Di Scienze Polari.; Italia. Universita' Ca' Foscari Di Venezia; ItaliaFil: Burgay, François. Universita' Ca' Foscari Di Venezia; Italia. Paul Scherrer Institute; SuizaFil: Fernandez, Rafael Pedro. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; ArgentinaFil: Turetta, Clara. Consiglio Nazionale Delle Ricerche. Istituto Di Scienze Polari.; Italia. Universita' Ca' Foscari Di Venezia; ItaliaFil: Cuevas, Carlos A.. Consejo Superior de Investigaciones CientĂficas. Instituto de QuĂmica FĂsica; EspañaFil: Kim, Kitae. Korea Polar Research Institute; Corea del SurFil: Kinnison, Douglas E.. National Center for Atmospheric Research; Estados UnidosFil: Lamarque, Jean-François. National Center for Atmospheric Research; Estados UnidosFil: de Blasi, Fabrizio. Consiglio Nazionale Delle Ricerche. Istituto Di Scienze Polari.; Italia. Universita' Ca' Foscari Di Venezia; ItaliaFil: Barbaro, Elena. Consiglio Nazionale Delle Ricerche. Istituto Di Scienze Polari.; Italia. Universita' Ca' Foscari Di Venezia; ItaliaFil: Corella, Juan Pablo. Consejo Superior de Investigaciones CientĂficas. Instituto de QuĂmica FĂsica; EspañaFil: Vallelonga, Paul. Universidad de Copenhagen; Dinamarca. University of Western Australia; AustraliaFil: Frezzotti, Massimo. UniversitĂ Roma Tre Iii. Dipartimento Di Scienze.; ItaliaFil: Barbante, Carlo. Consiglio Nazionale Delle Ricerche. Istituto Di Scienze Polari.; Italia. Universita' Ca' Foscari Di Venezia; ItaliaFil: Saiz LĂłpez, Alfonso. Consejo Superior de Investigaciones CientĂficas. Instituto de QuĂmica FĂsica; Españ
Exploring the genetics of irritable bowel syndrome: A GWA study in the general population and replication in multinational case-control cohorts
OBJECTIVE:
IBS shows genetic predisposition, but adequately powered gene-hunting efforts have been scarce so far. We sought to identify true IBS genetic risk factors by means of genome-wide association (GWA) and independent replication studies.
DESIGN:
We conducted a GWA study (GWAS) of IBS in a general population sample of 11\u2005326 Swedish twins. IBS cases (N=534) and asymptomatic controls (N=4932) were identified based on questionnaire data. Suggestive association signals were followed-up in 3511 individuals from six case-control cohorts. We sought genotype-gene expression correlations through single nucleotide polymorphism (SNP)-expression quantitative trait loci interactions testing, and performed in silico prediction of gene function. We compared candidate gene expression by real-time qPCR in rectal mucosal biopsies of patients with IBS and controls.
RESULTS:
One locus at 7p22.1, which includes the genes KDELR2 (KDEL endoplasmic reticulum protein retention receptor 2) and GRID2IP (glutamate receptor, ionotropic, delta 2 (Grid2) interacting protein), showed consistent IBS risk effects in the index GWAS and all replication cohorts and reached p=9.31
710(-6) in a meta-analysis of all datasets. Several SNPs in this region are associated with cis effects on KDELR2 expression, and a trend for increased mucosal KDLER2 mRNA expression was observed in IBS cases compared with controls.
CONCLUSIONS:
Our results demonstrate that general population-based studies combined with analyses of patient cohorts provide good opportunities for gene discovery in IBS. The 7p22.1 and other risk signals detected in this study constitute a good starting platform for hypothesis testing in future functional investigations.
Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions
Advanced liver disease outcomes after hepatitis C eradication by human immunodeficiency virus infection in PITER cohort
Liver disease progression after Hepatitis C Virus (HCV) eradication following direct-acting antiviral (DAA) treatment in the real-life setting according to Human Immunodeficiency Virus (HIV) coinfection was evaluated
Antarctic ozone hole modifies iodine geochemistry on the Antarctic Plateau
Polar stratospheric ozone has decreased since the 1970s due to anthropogenic emissions of chlorofluorocarbons and halons, resulting in the formation of an ozone hole over Antarctica. The effects of the ozone hole and the associated increase in incoming UV-radiation on terrestrial and marine ecosystems are well studied, however the impact on geochemical cycles of ice photoactive elements, such as iodine, remains almost unexplored. Here, we present the first iodine record from the inner Antarctic Plateau (Dome C) that covers approximately the last 212 years (1800-2012 CE). Our results show that iodine concentration in ice remained fairly constant during the pre-ozone hole period (1800-1974 CE) but has declined twofold since the onset of the ozone hole era (~1975 CE), closely tracking the total ozone evolution over Antarctica. Based on ice core observations, laboratory measurements and chemistry-climate model simulations, we propose that the iodine decrease since ~1975 is caused by enhanced iodine re-emission from snowpack due to the ozone hole driven increase in UV-radiation reaching the Antarctic Plateau. These findings suggest the potential for ice core iodine records from the inner Antarctic Plateau as an archive for past stratospheric ozone trends.Fil: Spolaor, Andrea. National Research Council of Italy. Institute of Polar Sciences; Italia. UniversitĂ Ca’ Foscari di Venezia; ItaliaFil: Burgay, François. UniversitĂ Ca’ Foscari di Venezia; Italia. Paul Scherrer Institut. Laboratory of Environmental Chemistry; SuizaFil: Fernandez, Rafael Pedro. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mendoza. Instituto Interdisciplinario de Ciencias Básicas. - Universidad Nacional de Cuyo. Instituto Interdisciplinario de Ciencias Básicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Turetta, Carla. National Research Council of Italy, Institute of Polar Sciences; Italia. UniversitĂ Ca’ Foscari di Venezia; ItaliaFil: Cuevas, Carlos A.. Consejo Superior de Investigaciones CientĂficas. Instituto de QuĂmica FĂsica; EspañaFil: Kim, Kitae. Korea Polar Research Institute; Corea del SurFil: Kinnison, Douglas E.. National Center for Atmospheric Research; Estados UnidosFil: Lamarque, Jean-Francoise. National Center for Atmospheric Research; Estados UnidosFil: de Blasi, Fabrizio. National Research Council of Italy, Institute of Polar Sciences; Italia. UniversitĂ Ca’ Foscari di Venezia; ItaliaFil: Barbaro, Elena. National Research Council of Italy, Institute of Polar Sciences; Italia. UniversitĂ Ca’ Foscari di Venezia; ItaliaFil: Corella, Juan Pablo. Consejo Superior de Investigaciones CientĂficas. Instituto de QuĂmica FĂsica; EspañaFil: Barbante, Carlo. National Research Council of Italy, Institute of Polar Sciences; ItaliaFil: Saiz LĂłpez, Alfonso. Consejo Superior de Investigaciones CientĂficas. Instituto de QuĂmica FĂsica; EspañaFil: Vallelonga, Paul. University of Copenhagen, Physics of Ice, Climate and Earth, Niels Bohr Institute; DinamarcaFil: Massimo, Frezzotti. UniversitĂ Roma Tre III; ItaliaFil: Barbante, Carlo. National Research Council of Italy, Institute of Polar Sciences; Italia. UniversitĂ Ca’ Foscari di Venezia; ItaliaFil: Saiz LĂłpez, Alfonso. Consejo Superior de Investigaciones CientĂficas. Instituto de QuĂmica FĂsica; EspañaEuropean Geosciences Union General AssemblyVienaAustriaCopernicus Meeting
Assessment of the dynamics of atrial signals and local atrial period series during atrial fibrillation: effects of isoproterenol administration
BACKGROUND: The autonomic nervous system (ANS) plays an important role in the genesis and maintenance of atrial fibrillation (AF), but quantification of its electrophysiologic effects is extremely complex and difficult. Aim of the study was to evaluate the capability of linear and non-linear indexes to capture the fine changing dynamics of atrial signals and local atrial period (LAP) series during adrenergic activation induced by isoproterenol (a sympathomimetic drug) infusion. METHODS: Nine patients with paroxysmal or persistent AF (aged 60 ± 6) underwent electrophysiological study in which isoproterenol was administered to patients. Atrial electrograms were acquired during i) sinus rhythm (SR); ii) sinus rhythm during isoproterenol (SRISO) administration; iii) atrial fibrillation (AF) and iv) atrial fibrillation during isoproterenol (AFISO) administration. The level of organization between two electrograms was assessed by the synchronization index (S), whereas the degree of recurrence of a pattern in a signal was defined by the regularity index (R). In addition, the level of predictability (LP) and regularity of LAP series were computed. RESULTS: LAP series analysis shows a reduction of both LP and R index during isoproterenol infusion in SR and AF (R(SR )= 0.75 ± 0.07 R(SRISO )= 0.69 ± 0.10, p < 0.0001; R(AF )= 0.31 ± 0.08 R(AFISO )= 0.26 ± 0.09, p < 0.0001; LP(SR )= 99.99 ± 0.001 LP(SRISO )= 99.97 ± 0.03, p < 0.0001; LP(AF )= 69.46 ± 21.55 LP(AFISO )= 55 ± 24.75; p < 0.0001). Electrograms analysis shows R index reductions both in SR (R(SR )= 0.49 ± 0.08 R(SRISO )= 0.46 ± 0.09 p < 0.0001) and in AF (R(AF )= 0.29 ± 0.09 R(AFISO )= 0.28 ± 0.08 n.s.). CONCLUSIONS: The proposed parameters succeeded in discriminating the subtle changes due to isoproterenol infusion during both the rhythms especially when considering LAP series analysis. The reduced value of analyzed parameters after isoproterenol administration could reflect an important pro-arrhythmic influence of adrenergic activation on favoring maintenance of AF
A real-time KLT implementation for radio-SETI applications
SETI, the Search for ExtraTerrestrial Intelligence, is the search for radio signals emitted by alien civilizations living in the Galaxy. Narrow-band FFT-based approaches have been preferred in SETI, since their computation time only grows like N*lnN, where N is the number of time samples. On the contrary, a wide-band approach based on the Kahrunen-Lo`eve Transform (KLT) algorithm would be preferable, but it would scale like N*N. In this paper, we describe a hardware-software infrastructure based on FPGA boards and GPU-based PCs that circumvents this computation-time problem allowing for a real-time KLT
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