1,507 research outputs found

    Transcending conventional biometry frontiers: Diffusive Dynamics PPG Biometry

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    In the first half of the 20th century, a first pulse oximeter was available to measure blood flow changes in the peripheral vascular net. However, it was not until recent times the PhotoPlethysmoGraphic (PPG) signal used to monitor many physiological parameters in clinical environments. Over the last decade, its use has extended to the area of biometrics, with different methods that allow the extraction of characteristic features of each individual from the PPG signal morphology, highly varying with time and the physical states of the subject. In this paper, we present a novel PPG-based biometric authentication system based on convolutional neural networks. Contrary to previous approaches, our method extracts the PPG signal's biometric characteristics from its diffusive dynamics, characterized by geometric patterns image in the (p, q)-planes specific to the 0-1 test. The diffusive dynamics of the PPG signal are strongly dependent on the vascular bed's biostructure, which is unique to each individual, and highly stable over time and other psychosomatic conditions. Besides its robustness, our biometric method is anti-spoofing, given the convoluted nature of the blood network. Our biometric authentication system reaches very low Equal Error Rates (ERRs) with a single attempt, making it possible, by the very nature of the envisaged solution, to implement it in miniature components easily integrated into wearable biometric systems.Comment: 18 pages, 6 figures, 4 table

    Heterogeneous vancomycin-intermediate susceptibility in a community-associated methicillin-resistant Staphylococcus aureus epidemic clone, in a case of Infective Endocarditis in Argentina

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    BACKGROUND: Community-Associated Methicillin Resistant Staphylococcus aureus (CA-MRSA) has traditionally been related to skin and soft tissue infections in healthy young patients. However, it has now emerged as responsible for severe infections worldwide, for which vancomycin is one of the mainstays of treatment. Infective endocarditis (IE) due to CA-MRSA with heterogeneous vancomycin-intermediate susceptibility-(h-VISA) has been recently reported, associated to an epidemic USA 300 CA-MRSA clone. CASE PRESENTATION: We describe the occurrence of h-VISA phenotype in a case of IE caused by a strain belonging to an epidemic CA-MRSA clone, distinct from USA300, for the first time in Argentina. The isolate h-VISA (SaB2) was recovered from a patient with persistent bacteraemia after a 7-day therapy with vancomycin, which evolved to fatal case of IE complicated with brain abscesses. The initial isolate-(SaB1) was fully vancomycin susceptible (VSSA). Although MRSA SaB2 was vancomycin susceptible (≤ 2 μg/ml) by MIC (agar and broth dilution, E-test and VITEK 2), a slight increase of MIC values between SaB1 and SaB2 isolates was detected by the four MIC methods, particularly for teicoplanin. Moreover, Sab2 was classified as h-VISA by three different screening methods [MHA5T-screening agar, Macromethod-E-test-(MET) and by GRD E-test] and confirmed by population analysis profile-(PAP). In addition, a significant increase in cell-wall thickness was revealed for SaB2 by electron microscopy. Molecular typing showed that both strains, SaB1 and SaB2, belonged to ST5 lineage, carried SCCmecIV, lacked Panton-Valentine leukocidin-(PVL) genes and had indistinguishable PFGE patterns (subtype I2), thereby confirming their isogenic nature. In addition, they were clonally related to the epidemic CA-MRSA clone (pulsotype I) detected in our country. CONCLUSIONS: This report demonstrates the ability of this epidemic CA-MRSA clone, disseminated in some regions of Argentina, to produce severe and rapidly fatal infections such as IE, in addition to its ability to acquire low-level vancomycin resistance; for these reasons, it constitutes a new challenge for the Healthcare System of this country.This study was supported by the National Council for Scientific Research and Technology of Argentina (CONICET), Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT - PICT 01630 to JLB), Secretaría de Ciencia y Técnica-Universidad Nacional de Córdoba (SECyT-UNC) and Agencia Córdoba Ciencia.S

    Intensive care unit discharge to the ward with a tracheostomy cannula as a risk factor for mortality: A prospective, multicenter propensity analysis

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    To analyze the impact of decannulation before intensive care unit discharge on ward survival in nonexperimental conditions. DESIGN: Prospective, observational survey. SETTING: Thirty-one intensive care units throughout Spain. PATIENTS: All patients admitted from March 1, 2008 to May 31, 2008. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: At intensive care unit discharge, we recorded demographic variables, severity score, and intensive care unit treatments, with special attention to tracheostomy. After intensive care unit discharge, we recorded intensive care unit readmission and hospital survival. STATISTICS: Multivariate analyses for ward mortality, with Cox proportional hazard ratio adjusted for propensity score for intensive care unit decannulation. We included 4,132 patients, 1,996 of whom needed mechanical ventilation. Of these, 260 (13%) were tracheostomized and 59 (23%) died in the intensive care unit. Of the 201 intensive care unit tracheostomized survivors, 60 were decannulated in the intensive care unit and 141 were discharged to the ward with cannulae in place. Variables associated with intensive care unit decannulation (non-neurologic disease [85% vs. 64%], vasoactive drugs [90% vs. 76%], parenteral nutrition [55% vs. 33%], acute renal failure [37% vs. 23%], and good prognosis at intensive care unit discharge [40% vs. 18%]) were included in a propensity score model for decannulation. Crude ward mortality was similar in decannulated and nondecannulated patients (22% vs. 23%); however, after adjustment for the propensity score and Sabadell Score, the presence of a tracheostomy cannula was not associated with any survival disadvantage with an odds ratio of 0.6 [0.3-1.2] (p=.1). CONCLUSION: In our multicenter setting, intensive care unit discharge before decannulation is not a risk factor

    MRI Investigation of the Differential Impact of Left Ventricular Ejection Fraction After Myocardial Infarction in Elderly vs. Nonelderly Patients to Predict Readmission for Heart Failure

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    Acute heart failure; Acute myocardial infarction; ElderlyInsuficiència cardíaca aguda; Infart agut de miocardi; Gent granInsuficiencia cardíaca aguda; Infarto agudo de miocardio; AncianoBackground Patients with ST-segment elevation myocardial infarction (STEMI), especially elderly individuals, have an increased risk of readmission for acute heart failure (AHF). Purpose To study the impact of left ventricular ejection fraction (LVEF) by MRI to predict AHF in elderly (>70 years) and nonelderly patients after STEMI. Study Type Prospective. Population Multicenter registry of 759 reperfused STEMI patients (23.3% elderly). Field Strength/Sequence 1.5-T. Balanced steady-state free precession (cine imaging) and segmented inversion recovery steady-state free precession (late gadolinium enhancement) sequences. Assessment One-week MRI-derived LVEF (%) was quantified. Sequential MRI data were recorded in 579 patients. Patients were categorized according to their MRI-derived LVEF as preserved (p-LVEF, ≥50%), mildly reduced (mr-LVEF, 41%–49%), or reduced (r-LVEF, ≤40%). Median follow-up was 5 [2.33–7.54] years. Statistical Tests Univariable (Student's t, Mann–Whitney U, chi-square, and Fisher's exact tests) and multivariable (Cox proportional hazard regression) comparisons and continuous-time multistate Markov model to analyze transitions between LVEF categories and to AHF. Hazard ratios (HR) with 95% confidence intervals (CIs) were computed. P < 0.05 was considered statistically significant. Results Over the follow-up period, 79 (10.4%) patients presented AHF. MRI-LVEF was the most robust predictor in nonelderly (HR 0.94 [0.91–0.98]) and elderly patients (HR 0.94 [0.91–0.97]). Elderly patients had an increased AHF risk across the LVEF spectrum. An excess of risk (compared to p-LVEF) was noted in patients with r-LVEF both in nonelderly (HR 11.25 [5.67–22.32]) and elderly patients (HR 7.55 [3.29–17.34]). However, the mr-LVEF category was associated with increased AHF risk only in elderly patients (HR 3.66 [1.54–8.68]). Less transitions to higher LVEF states (n = 19, 30.2% vs. n = 98, 53%) and more transitions to AHF state (n = 34, 53.9% vs. n = 45, 24.3%) were observed in elderly than nonelderly patients. Data Conclusion MRI-derived p-LVEF confers a favorable prognosis and r-LVEF identifies individuals at the highest risk of AHF in both elderly and nonelderly patients. Nevertheless, an excess of risk was also found in the mr-LVEF category in the elderly group. Evidence Level 2. Technical Efficacy Stage 2.Grant sponsor: This work was supported by “Instituto de Salud Carlos III” and “Fondos Europeos de Desarrollo Regional FEDER” (grant numbers PI20/00637, PI15/00531, and CIBERCV16/11/00486, CIBERCV16/11/00420, CIBERCV16/11/00479, and CM21/00175 to V.M.-G.), Fundació La Marató TV3 (grant 20153030-31-32), La Caixa Banking Foundation (HR17-00527) and by Conselleria de Educación – Generalitat Valenciana (PROMETEO/2021/008). J.G. acknowledges financial support from the “Agencia Estatal de Investigación” (grant FJC2020-043981-I/AEI/10.13039/501100011033)

    ZNF577 Methylation Levels in Leukocytes From Women With Breast Cancer Is Modulated by Adiposity, Menopausal State, and the Mediterranean Diet

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    The methylation levels of ZNF577 in breast tumors has been previously identified as a possible epigenetic mark of breast cancer associated with obesity. The aim of the current study was to investigate differences in methylation levels of ZNF577 depending on obesity, menopausal state and dietary pattern in blood leukocytes, a non-invasive sample. The methylation levels of ZNF577 of two CpG sites (CpGs) located in promoter and island previously identified as differentially methylated according to adiposity and menopausal state by 450 k array (cg10635122, cg03562414) were evaluated by pyrosequencing in DNA from the blood leukocytes of breast cancer patients [n = 90; n = 64 (71.1%) overweight/obesity and n = 26 (28.9%) normal-weight] and paired tumor tissue biopsies (n = 8 breast cancer patients with obesity; n = 3/5 premenopausal/postmenopausal women). Differences in methylation levels were evaluated at each CpGs individually and at the mean of the two evaluated CpGs. Adherence to the Mediterranean diet was evaluated using the MEDAS-validated questionnaire, and the consumption of food groups of interest was also evaluated using the recommended intakes of the Sociedad Espanola de Nutricion Comunitaria. The methylation levels of ZNF577 were correlated between paired leukocytes and breast tumor biopsies (r = 0.62; p = 0.001). Moreover, higher methylation was found in leukocytes from patients with obesity (p = 0.002) and postmenopausal patients (p = 0.022) than patients with normal-weight or premenopausal, respectively. After adjusting for the body mass index and age, higher levels of ZNF577 methylation were also found in women with greater adherence to the Mediterranean diet (p = 0.017) or specific foods. Relevantly, the methylation levels of ZNF577 showed a good ability for fish consumption detection [area under the ROC curve (AUC) = 0.72; p = 0.016]. In conclusion, the association between methylation of ZNF577 and adiposity, menopausal state, and adherence to the Mediterranean diet can be detected in the blood leukocytes. The results guarantee the need of performing further studies in longer longitudinal cohorts in order to elucidate the role of ZNF577 methylation in the association between breast cancer, adiposity and dietary patterns

    The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

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    The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected

    Does the disturbance hypothesis explain the biomass increase in basin-wide Amazon forest plot data?

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    Positive aboveground biomass trends have been reported from old-growth forests across the Amazon basin and hypothesized to reflect a large-scale response to exterior forcing. The result could, however, be an artefact due to a sampling bias induced by the nature of forest growth dynamics. Here, we characterize statistically the disturbance process in Amazon old-growth forests as recorded in 135 forest plots of the RAINFOR network up to 2006, and other independent research programmes, and explore the consequences of sampling artefacts using a data-based stochastic simulator. Over the observed range of annual aboveground biomass losses, standard statistical tests show that the distribution of biomass losses through mortality follow an exponential or near-identical Weibull probability distribution and not a power law as assumed by others. The simulator was parameterized using both an exponential disturbance probability distribution as well as a mixed exponential–power law distribution to account for potential large-scale blowdown events. In both cases, sampling biases turn out to be too small to explain the gains detected by the extended RAINFOR plot network. This result lends further support to the notion that currently observed biomass gains for intact forests across the Amazon are actually occurring over large scales at the current time, presumably as a response to climate change

    Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

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    This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin

    Database of spatial distribution of non indigenous species in Spanish marine waters

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    Research in marine Spanish waters are focused on several actions to achieve an effectively management on protected areas, with the active participation of the stakeholders and research as basic tools for decision-making. Among these actions, there is one about the knowledge and control on NIS. One of its objectives is the creation of NIS factsheets, which are going to be added to the National Marine Biodiversity Geographical System (GIS) providing complementary information about taxonomic classification, common names, taxonomic synonyms, species illustrations, identification morphological characters, habitat in the native and introduced regions, biological and ecological traits, GenBank DNA sequences, world distribution, first record and evolution in the introduced areas, likely pathways of introduction, effects in the habitats and interaction with native species, and potential management measures to apply. The database will also provide data for (1) the European online platforms, (2) the environmental assessment for the Descriptor 2 (D2-NIS) of the EU Marine Strategy Framework Directive (MSFD), as well as (3) supporting decisions made by stakeholders. It is the result of extensive collaboration among scientist, manager’s and citizen science in the Spanish North-Atlantic, South-Atlantic, Gibraltar Strait-Alboran, Levantine-Balearic and Canary Islands marine divisions, providing an updated overview of the spatial distribution of relevant extended and invasive NIS of recent and established NIS introduced by maritime transport and aquaculture pathways, as well as on cryptogenic or native species in expansion due to the climatic water warming trend
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