115 research outputs found

    VIX futures term structure and the expectations hypothesis

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    Tests of the expectations hypothesis reveal that the slope of the VIX futures term structure predicts the direction but not the magnitude of the evolution of the short-end of the curve, but predicts neither the direction nor the magnitude of short-term changes in the long-end of the curve. Relative value seeking spread trades, constructed to exploit such violations, deliver excess returns with annualized Sharpe ratios equal or greater than those of volatility-writing strategies deployed by VIX ETN’s for a majority of the 32 spread trade combinations tested. I demonstrate that profits from beta-neutral variations of the spread trades, which are not compensation for taking on equity downside risk by design, are propagated by inflows of capital into VIX futures markets, after controlling for factors that measure changes in the availability of hedge fund capital, risk appetite, and momentum. At the heart of profits, and by extension the term structure anomalies, is a disproportionally elevated basis propagated by long VIX demand that enters the futures market through ETN channels

    Metabolites, genomics, epigenomics, exposomics and health: Focus on serum bilirubin concentrations in subjects with metabolic syndrome from a Mediterranean population

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    Pòster presentat al congrés "Understanding Human Diseases Through Metabolomics: Interactions Among the Genome, Proteome, Gut Microbiome and Nutrition", Metabolomics and Human Health, Gordon Research Conference (February 3 - 8, 2019 Ventura, CA, United States)Although metabolomics aims at the measurement of small molecules (metabolites) in a biological sample, this knowledge requires additional information on the related genetic variants, epigenetic regulators and environmental factors (diet, smoking, physical activity, etc.) in order to translate the knowledge into actionable therapeutic or preventive evidence for complex disease outcomes. We focused on serum bilirubin, a metabolite generated when heme oxygenase catalyzes the degradation of heme (Figure 1). This produces biliverdin, which is converted into bilirubin by biliverdinreductase. Bilirubin is further processed in hepatocytes, where unconjugated bilirubin is conjugated by uridine diphosphate-glucuronosyltransferase (UDP-GT) to a water-soluble form for excretion. For decades, increased serum bilirubin concentrations were considered a threatening sign of underlying liver disease and had been associated with neonatal jaundice. However, data from recent years show that bilirubin is a powerful antioxidant and suggest that slightly increased serum bilirubin concentrations are protective against oxidative stress-related diseases

    An IDA-PBC Design with Integral Action for Output Voltage Regulation in an Interleaved Boost Converter for DC Microgrid Applications

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    This paper describes the output voltage regulation control for an interleaved connected to a direct current (DC) microgrid considering bidirectional current flows. The proposed controller is based on an interconnection and damping passivity-based control (IDA-PBC) approach with integral action that regulates the output voltage profile at its assigned reference. This approach designs a control law via nonlinear feedback that ensures asymptotic stability in a closed-loop in the sense of Lyapunov. Moreover, the IDA-PBC design adds an integral gain to eliminate the possible tracking errors in steady-state conditions. Numerical simulations in the Piecewise Linear Electrical Circuit Simulation (PLECS) package for MATLAB/Simulink demonstrate that the effectiveness of the proposed controller is assessed and compared with a conventional proportional-integral controller under different scenarios considering strong variations in the current injected/absorbed by the DC microgrid.Fil: Montoya Giraldo, Oscar Danilo. Universidad Distrital Francisco José de Caldas; ColombiaFil: Serra, Federico Martin. Universidad Nacional de San Luis. Facultad de Ingeniería y Ciencias Agropecuarias. Laboratorio de Control Automático; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Gil González, Walter. Institución Universitaria Pascual Bravo; ColombiaFil: Asensio, Eduardo Maximiliano. Universidad Nacional de San Luis. Facultad de Ingeniería y Ciencias Agropecuarias. Laboratorio de Control Automático; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Bosso, Jonathan Emmanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; Argentina. Universidad Nacional de San Luis. Facultad de Ingeniería y Ciencias Agropecuarias. Laboratorio de Control Automático; Argentin

    Effect of a Biostimulant Based on Polyphenols and Glycine Betaine on Tomato Plants¿ Responses to Salt Stress

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    [EN] Climate change accentuates abiotic stress conditions putting at risk several commercial cultivars particularly vulnerable to salinity in the early stages of development, which makes adopting new technologies in tune with the environment necessary to mitigate its impact. In this study, we tested the possible effects of a commercial biostimulant (BALOX®) on enhancing salt stress tolerance in salt-treated tomato plants, analysing plant growth and several stress biochemical markers: photosynthetic pigments, ion contents in roots and leaves, leaf concentrations of different osmolytes, oxidative stress markers, non-enzymatic antioxidants, and the specific activities of major antioxidant enzymes. The experimental design consisted of three soil salinity levels (non-saline, saline, and very saline), two biostimulant doses (0.4 mL and 0.8 mL of the BALOX® stock per litre of irrigation water), and the non-treated control (without biostimulant), evaluated at 30 and 60 days of treatment. The biostimulant favoured plant growth, especially at the root level and in saline soils. In addition, it helped reduce Na+ and Cl uptake by the roots and seemed to stimulate, to some extent, K+ and Ca2+ transport to the aerial part of the plant. The BALOX® application significantly reduced the level of stress affecting the plants in saline soils, as shown by the decrease in the contents of proline and oxidative stress biomarkers and the activity of salt-induced antioxidant enzymes. Some of the biostimulant effects were also observed under low salinity conditions; therefore, in addition to enhancing salt stress responses, BALOX® appears to stimulate the growth of tomato plants through a general improvement of photosynthesis and primary metabolism.This research was partly funded by the company Innovak Global and partly by UPV through internal funds to S.I.-A., M.B. and O.V.Zuzunaga-Rosas, J.; González-Orenga, S.; Tofei, AM.; Boscaiu, M.; Moreno-Ramón, H.; Ibañez Asensio, S.; Vicente, O. (2022). Effect of a Biostimulant Based on Polyphenols and Glycine Betaine on Tomato Plants¿ Responses to Salt Stress. Agronomy. 12(9):1-26. https://doi.org/10.3390/agronomy1209214212612

    Crosstalk between smoking and the genome in older subjects with metabolic syndrome through genomics, epigenomics and transcriptomics

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    Pòster presentat a EMBO - EMBL Symposia Multiomics to Mechanisms - Challenges in Data Integration. September (11th – 13th 2019 European Molecular Biology Laboratory. Heidelberg, Germany)Tobacco smoking (Figure 1) is a major cause of cardiovascular diseases (CVD), and appears to have a multiplicative interaction with the other major CVD risk factors (lipids, hypertension, diabetes and others present in the metabolic syndrome (MetS). Several omics have analyzed the separate effects of tobacco smoking on the genome, epigenome, transcriptome, metabolome, etc. However an integrated omics approach can help to better understand the crosstalk between tobacco smoking and the genome

    Untargeted metabolomics based on ultra-high-performance liquid chromatography-ion mobility-quadrupole time-of-flight mass spectrometry for biomarker discovery of orange intake in a cross-over trial

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    Pòster presentat al congrés "Understanding Human Diseases Through Metabolomics: Interactions Among the Genome, Proteome, Gut Microbiome and Nutrition", Metabolomics and Human Health, Gordon Research Conference (February 3 - 8, 2019 Ventura, CA, United States)Diet is one of the most important lifestyle factors associated with health status. Currently, one of the main limitations of nutritional epidemiology and nutritional genomics is the difficulty in the measurements of dietary intake. In observational studies carried out in a large number of participants, the most commonly applied tools for estimating dietary intake are based on self-reporting, including food frequency questionnaires (FFQ) for the assessment of regular consumption (usually 1-year), or 24-h recalls for 1-day assessment. However, such instruments for data collection may contain several recall bias and other systematic or random errors that may have a great effect in the subsequent associations found. Although in recent years, it has been an improvement in increasing the validity and precision of food questionnaires due to the use of the new information technologies (Figure 1), these instruments are still biased and additional information based on objective biomarkers of food intake is needed

    Ultra-Performance Liquid Chromatography-Ion Mobility Separation-Quadruple Time-of-Flight MS (UHPLC-IMS-QTOF MS) Metabolomics for Short-Term Biomarker Discovery of Orange Intake: A Randomized, Controlled Crossover Study

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    A major problem with dietary assessments is their subjective nature. Untargeted metabolomics and new technologies can shed light on this issue and provide a more complete picture of dietary intake by measuring the profile of metabolites in biological samples. Oranges are one of the most consumed fruits in the world, and therefore one of the most studied for their properties. The aim of this work was the application of untargeted metabolomics approach with the novel combination of ion mobility separation coupled to high resolution mass spectrometry (IMS-HRMS) and study the advantages that this technique can bring to the area of dietary biomarker discovery, with the specific case of biomarkers associated with orange consumption (Citrus reticulata) in plasma samples taken during an acute intervention study (consisting of a randomized, controlled crossover trial in healthy individuals). A total of six markers of acute orange consumption, including betonicines and conjugated flavonoids, were identified with the experimental data and previous literature, demonstrating the advantages of ion mobility in the identification of dietary biomarkers and the benefits that an additional structural descriptor, as the collision cross section value (CCS), can provide in this area

    MicroRNAs and Drinking: Association between the Pre-miR-27a rs895819 Polymorphism and Alcohol Consumption in a Mediterranean Population

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    Recently, microRNAs (miRNA) have been proposed as regulators in the different processes involved in alcohol intake, and differences have been found in the miRNA expression profile in alcoholics. However, no study has focused on analyzing polymorphisms in genes encoding miRNAs and daily alcohol consumption at the population level. Our aim was to investigate the association between a functional polymorphism in the pre-miR-27a (rs895819 A>G) gene and alcohol consumption in an elderly population. We undertook a cross-sectional study of PREvencion con DIeta MEDiterranea (PREDIMED)-Valencia participants (n = 1007, including men and women aged 67 +/- 7 years) and measured their alcohol consumption (total and alcoholic beverages) through a validated questionnaire. We found a strong association between the pre-miR-27a polymorphism and total alcohol intake, this being higher in GG subjects (5.2 +/- 0.4 in AA, 5.9 +/- 0.5 in AG and 9.1 +/- 1.8 g/day in GG; p(adjusted) = 0.019). We also found a statistically-significant association of the pre-miR-27a polymorphism with the risk of having a high alcohol intake (> 2 drinks/day in men and > 1 in women): 5.9\% in AA versus 17.5\% in GG; p(adjusted) < 0.001. In the sensitivity analysis, this association was homogeneous for sex, obesity and Mediterranean diet adherence. In conclusion, we report for the first time a significant association between a miRNA polymorphism (rs895819) and daily alcohol consumption.This study was funded, by the Spanish Ministry of Health (Instituto de Salud Carlos III) and the Ministerio de Economia y Competitividad-Fondo Europeo de Desarrollo Regional (Projects CNIC-06/2007, RTIC G03/140, CIBER 06/03, PI06-1326, PI07-0954, PI11/02505, SAF2009-12304, AGL2010-22319-C03-03 and PRX14/00527), by the lUniversity Jaume I (Project P1-1B2013-54), by Contracts 53-K06-5-10 and 58-1950-9-001 from the U.S. Department of Agriculture Research Service, USA, by the Generalitat Valenciana (ACOMP2010-181, AP111/10, AP-042/11, ACOM2011/145, ACOMP/2012/190, ACOMP/2013/159 and ACOMP/213/165), and with the collaboration of the Real Colegio Complutense at Harvard University, Cambridge. MA, USA. Rocio Barragon's contract is funded by the Ayudas para la contratacion de personal investigador en formacion de caracter predoctoral, Programa ``VALencia Investigacion mas Desarrollo´´ (VALi+d). Conselleria d'Educacio, Investigacio, Cultura i Esport. Generalitat Valenciana, Spain (ACIF/2013/168).S

    The effect of left ventricular dysfunction on right ventricle ejection fraction during exercise in heart failure patients: Implications in functional capacity and blood pressure response

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    Background: The aim of this study was to assess the effect of left ventricular dysfunction on right ventricular ejection fraction during exercise in heart failure patients and its implications in functional capacity and blood pressure response. Methods: In a cross-sectional study 65 patients with heart failure were included. Left and right ventricular ejection fractions were evaluated by radio-isotopic ventriculography. All subjects underwent an exercise treadmill test (Bruce modified protocol). Systolic and diastolic blood pressures were also recorded. Results: From the total population, 38 (58.46%) showed a significant increase (&#8805; 5%) in left ventricular ejection fraction (LVEF) and 27 (41.5%) showed a significant decrease in LVEF (&#8805; 5%) after the stress test. Patients with a significant reduction in LVEF during stress had lower exercise tolerance (4.1 &#177; 2.5 vs. 6.1 &#177; 2.5 METs, p = 0.009) compared to those who showed an increase in LVEF. Diastolic blood pressure was higher at rest among those who had a reduced LVEF during stress (83 &#177; 12.2 vs. 72.6 &#177; 12.2 mm Hg, p = 0.035) and during exercise (95 &#177; 31.3 vs. 76.9 &#177; 31.3 mm Hg, p = 0.057), as well as mean arterial pressure in the same group (97.1 &#177; 11.6 mm Hg, p = 0.05). In addition, this group decrease of &#8211;8.8 &#177; 51.6% in the right ventricular ejection fraction after exercise compared to an increase of 27.3 &#177; &#177; 49.1% (p = 0.007) among the patients with an increase in LVEF. Conclusions: Biventricular systolic dysfunction during exercise is associated with higher rest and stress blood pressure and worse functional capacity

    Circulating adiponectin and Its association with metabolic traits and Type 2 Diabetes: gene-diet interactions focusing on selected gene variants and at the genome-wide level in high-cardiovascular risk mediterranean subjects

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    Adiponectin is gaining renewed interest since, in addition to its possible protective role against insulin resistance and arteriosclerosis, recent studies suggest other additional favorable effects. However, the influence of gene-diet interactions on plasma adiponectin levels is still little understood. We analyzed the association between plasma adiponectin levels and various metabolic traits in a high-cardiovascular risk Mediterranean population, as well as the genetic effect of four candidate single-nucleotide polymorphisms (SNPs) in the adiponectin gene (ADIPOQ) and their interactions with the Mediterranean dietary pattern. Additionally, we explored, at the genome-wide level, the SNPs most associated with plasma adiponectin levels, as well as gene–diet interactions with the Mediterranean diet. In the 954 participants studied (aged 55–80 years), plasma adiponectin levels were strongly associated with plasma HDL-C concentrations (p = 6.6 × 10−36) and inversely related to triglycerides (p = 4.7 × 10−18), fasting glucose (p = 3.5 × 10−16) and type 2 diabetes (p = 1.4 × 10−7). Of the four pre-selected ADIPOQ candidate SNPs, the one most associated with plasma adiponectin was the −11391G > A (rs17300539) promoter SNP (p = 7.2 × 10−5, in the multivariable adjusted model). No significant interactions with the Mediterranean diet pattern were observed for these SNPs. Additionally, in the exploratory genome-wide association study (GWAS), we found new SNPs associated with adiponectin concentrations at the suggestive genome-wide level (p < 1 × 10−5) for the whole population, including the lead SNP rs9738548 (intergenic) and rs11647294 in the VAT1L (Vesicle Amine Transport 1 Like) gene. We also found other promising SNPs on exploring different strata such as men, women, diabetics and non-diabetics (p = 3.5 × 10−8 for rs2850066). Similarly, we explored gene–Mediterranean diet interactions at the GWAS level and identified several SNPs with gene–diet interactions at p < 1 × 10−5. A remarkable gene–diet interaction was revealed for the rs2917570 SNP in the OPCML (Opioid Binding Protein/Cell Adhesion Molecule Like) gene, previously reported to be associated with adiponectin levels in some populations. Our results suggest that, in this high-cardiovascular risk Mediterranean population, and even though adiponectin is favorably associated with metabolic traits and lower type 2 diabetes, the gene variants more associated with adiponectin may be population-specific, and some suggestive gene–Mediterranean diet interactions were detected
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