91 research outputs found

    Análisis de una estrategia con opciones: Bull put ladder sobre Enegás

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    [Resumen]: Este estudio tiene como objetivo analizar una estrategia de inversión que consiste en una combinación de opciones financieras conocida como bull put ladder, con el fin de adqurir un conocimiento más amplio sobre los derivados financieros, investigar cuán útil podría ser su uso en una situación real, y mejorar las capacidades con respecto al uso de una herramienta crucial para la valoración financiera como es la hoja de cálculo. El estudio se inicia con una revisión teórica sobre las características y los elementos principales de las opciones financieras, explicando los tipos de opciones, situaciones y posiciones que se pueden tener. En segundo lugar, se ha hecho especial hincapié en la prima de la opción y en uno de los modelos que explican su valor teórico: el modelo de Black-Sholes. Además, se ha introducido una explicación de qué y cuáles son las griegas. A continuación, se introduce una explicación terórica de la estrategia estudiada, bull put ladder, mostrando una aproximación intuitiva a su uso. Una vez presentada la estrategia, se lleva el caso a la práctica utilizando datos de cotización de las acciones de la empresa Enagás, siguiendo las indicaciones del tutor. Con la ayuda de fuentes oficiales como el MEFF o Infobolsa se consiguen datos reales que permiten obtener una conclusión sobre la estrategia. Por último, el estudio concluye con la explicación del uso de la hoja de cálculo para elaborar un prototipo de un modelo que soporte las decisiones relativas a la estrategia seleccionada. En definitiva, se puede concluír que la estrategia bull put ladder es recomendable para expectativas bajistas.[Abstract]: This study aims to analyze an investment strategy consisting of a combination of financial options known as Bull Put Ladder, in order to acquire a broader knowledge on financial derivatives, to investigate how useful could be its use in a real situation and to improve skills with respect to the use of a cross-functional tool for financial valuation as the spreadsheet. The study begins with a theoretical review on the characteristics and main elements of the financial options, explaining the types of options, situations and positions that may have. Second, special emphasis has been placed on the premium of the option and on one of the models that explain its theoretical value: the Black-Sholes model. In addition, an explanation has been introduced of what are the Greeks. Next, a theoretical explanation of the studied strategy, bull put ladder, is introduced, showing an intuitive approach to its use. Once the strategy is presented, the case is put into practice using data from the stocks of the company Enagás, following the instructions of the tutor. With help of official sources such as MEFF or Infobolsa, real data are obtained in order to deliver a conclusion about the strategy. Finally, the study concludes with the explanation of the use of the spreadsheet to elaborate a prototype of a model that supports the decisions related to this strategy. Ultimately, it can be concluded that the Bull Put Ladder strategy is recommended for bearish expectations.Traballo fin de grao (UDC.ECO). ADE. Curso 2016/201

    Direct low field J-edited diffusional proton NMR spectroscopic measurement of COVID-19 inflammatory biomarkers in human serum.

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    A JEDI NMR pulse experiment incorporating relaxational, diffusional and J-modulation peak editing has been implemented for a low field (80 MHz proton resonance frequency) spectrometer system to measure quantitatively two recently discovered plasma markers of SARS-CoV-2 infection and general inflammation. JEDI spectra capture a unique signature of two biomarker signals from acetylated glycoproteins (Glyc) and the supramolecular phospholipid composite (SPC) signals that are relatively enhanced by the combination of relaxation, diffusion and J-editing properties of the JEDI experiment that strongly attenuate contributions from the other molecular species in plasma. The SPC/Glyc ratio data were essentially identical in the 600 MHz and 80 MHz spectra obtained (R2 = 0.97) and showed significantly different ratios for control (n = 28) versus SARS-CoV-2 positive patients (n = 29) (p = 5.2 × 10-8 and 3.7 × 10-8 respectively). Simplification of the sample preparation allows for data acquisition in a similar time frame to high field machines (∼4 min) and a high-throughput version with 1 min experiment time could be feasible. These data show that these newly discovered inflammatory biomarkers can be measured effectively on low field NMR instruments that do not not require housing in a complex laboratory environment, thus lowering the barrier to clinical translation of this diagnostic technology

    Direct low field J-edited diffusional proton NMR spectroscopic measurement of COVID-19 inflammatory biomarkers in human serum

    Get PDF
    A JEDI NMR pulse experiment incorporating relaxational, diffusional and J-modulation peak editing has been implemented for a low field (80 MHz proton resonance frequency) spectrometer system to measure quantitatively two recently discovered plasma markers of SARS-CoV-2 infection and general inflammation. JEDI spectra capture a unique signature of two biomarker signals from acetylated glycoproteins (Glyc) and the supramolecular phospholipid composite (SPC) signals that are relatively enhanced by the combination of relaxation, diffusion and J-editing properties of the JEDI experiment that strongly attenuate contributions from the other molecular species in plasma. The SPC/Glyc ratio data were essentially identical in the 600 MHz and 80 MHz spectra obtained (R2 = 0.97) and showed significantly different ratios for control (n = 28) versus SARS-CoV-2 positive patients (n = 29) (p = 5.2 × 10−8 and 3.7 × 10−8 respectively). Simplification of the sample preparation allows for data acquisition in a similar time frame to high field machines (∼4 min) and a high-throughput version with 1 min experiment time could be feasible. These data show that these newly discovered inflammatory biomarkers can be measured effectively on low field NMR instruments that do not not require housing in a complex laboratory environment, thus lowering the barrier to clinical translation of this diagnostic technology

    A Metabolomics Signature Linked To Liver Fibrosis In The Serum Of Transplanted Hepatitis C Patients

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    Liver fibrosis must be evaluated in patients with hepatitis C virus (HCV) after liver transplantation because its severity affects their prognosis and the recurrence of HCV. Since invasive biopsy is still the gold standard to identify patients at risk of graft loss from rapid fibrosis progression, it becomes crucial the development of new accurate, non-invasive methods that allow repetitive examination of the patients. Therefore, we have developed a non-invasive, accurate model to distinguish those patients with different liver fibrosis stages. Two hundred and three patients with HCV were histologically classified (METAVIR) into five categories of fibrosis one year after liver transplantation. In this cross-sectional study, patients at fibrosis stages F0-F1 (n = 134) were categorised as "slow fibrosers" and F2-F4 (n = 69) as "rapid fibrosers". Chloroform/methanol serum extracts were analysed by reverse ultra-high performance liquid chromatography coupled to mass spectrometry. A diagnostic model was built through linear discriminant analyses. An algorithm consisting of two sphingomyelins and two phosphatidylcholines accurately classifies rapid and slow fibrosers after transplantation. The proposed model yielded an AUROC of 0.92, 71% sensitivity, 85% specificity, and 84% accuracy. Moreover, specific bile acids and sphingomyelins increased notably along with liver fibrosis severity, differentiating between rapid and slow fibrosers

    Fatty liver and fibrosis in glycine N-methyltransferase knockout mice is prevented by nicotinamide

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    Deletion of glycine N-methyltransferase (GNMT) in mice, the main gene involved in liver S-adenosylmethionine (SAMe) catabolism, leads to the hepatic accumulation of this molecule and the development of fatty liver and fibrosis. To demonstrate that the excess of hepatic SAMe is the main agent contributing to liver disease in GNMT-KO mice, we treated 1.5-month old GNMT-KO mice for 6 weeks with nicotinamide (NAM), a substrate of the enzyme NAM N-methyltransferase. NAM administration markedly reduced hepatic SAMe content, prevented DNA-hypermethylation and normalized the expression of critical genes involved in fatty acid metabolism, oxidative stress, inflammation, cell proliferation, and apoptosis. More important, NAM treatment prevented the development of fatty liver and fibrosis in GNMT-KO mice. Because GNMT expression is down-regulated in patients with cirrhosis and there are subjects with GNMT mutations who have spontaneous liver disease, the clinical implication of the present findings is obvious at least with respect to these latter individuals. Especially since NAM has been used for many years to treat a broad spectrum of diseases including pellagra and diabetes without significant side effects, it should be considered in subjects with GNMT mutations.ConclusionsThese results indicate that the anomalous accumulation of SAMe in GNMT-KO mice can be corrected by NAM treatment leading to the normalization of the expression of many genes involved in fatty acid metabolism, oxidative stress, inflammation, cell proliferation and apoptosis, and to the reversion of the appearance of the pathologic phenotype

    Sensitive detection of SARS-CoV-2 seroconversion by flow cytometry reveals the presence of nucleoprotein-reactive antibodies in unexposed individuals

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    There is an ongoing need of developing sensitive and specific methods for the determination of SARS-CoV-2 seroconversion. For this purpose, we have developed a multiplexed flow cytometric bead array (C19BA) that allows the identification of IgG and IgM antibodies against three immunogenic proteins simultaneously: the spike receptor-binding domain (RBD), the spike protein subunit 1 (S1) and the nucleoprotein (N). Using different cohorts of samples collected before and after the pandemic, we show that this assay is more sensitive than ELISAs performed in our laboratory. The combination of three viral antigens allows for the interrogation of full seroconversion. Importantly, we have detected N-reactive antibodies in COVID-19-negative individuals. Here we present an immunoassay that can be easily implemented and has superior potential to detect low antibody titers compared to current gold standard serology methods.Acknowledgements: We thank Petros Tyrakis and Iván Martínez-Forero for critical reading and editing of the manuscript. Support was provided by the Severo Ochoa Excellence Accreditation from MCIU (SEV-2016-0644) and the SPRI I+D COVID-19 fund (Gobierno Vasco). Personal fellowships: A.A.-V. (La Caixa Inphinit LCF/BQ/DR20/11790022), A.B. (AECC Bizkaia), A.G.d.R (Bikaintek), A.P. (Ramón y Cajal), B.J.-L. (Gob. Vasco), and E.P.-F. (Juan de la Cierva-Formación). M.L.M.-C. acknowledges RTC2019-007125-1, DTS20/00138, SAF2017-87301-R, and BBVA UMBRELLA project. M.L.-H. acknowledges the ISCIII for grant COV20-0170 and the Government of Cantabria for grant 2020UIC22-PUB-0019. O.M., J.-M.M., and N.G.A.A. acknowledge the Agencia Estatal de Investigación (Spain) for grants CTQ2015-68756-R, RTI2018-101269-BI00, and RTI2018-095700-B-I00, respectively. A.P. has received grant funding from the European Research Council (ERC), grant agreement number 804236 (Horizon 2020), and the FERO Foundation

    Sirtuin 1 regulation of developmental genes during differentiation of stem cells

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    The longevity-promoting NAD+-dependent class III histone deacetylase Sirtuin 1 (SIRT1) is involved in stem cell function by controlling cell fate decision and/or by regulating the p53-dependent expression of NANOG. We show that SIRT1 is down-regulated precisely during human embryonic stem cell differentiation at both mRNA and protein levels and that the decrease in Sirt1 mRNA is mediated by a molecular pathway that involves the RNA-binding protein HuR and the arginine methyltransferase coactivator-associated arginine methyltransferase 1 (CARM1). SIRT1 down-regulation leads to reactivation of key developmental genes such as the neuroretinal morphogenesis effectors DLL4, TBX3, and PAX6, which are epigenetically repressed by this histone deacetylase in pluripotent human embryonic stem cells. Our results indicate that SIRT1 is regulated during stem cell differentiation in the context of a yet-unknown epigenetic pathway that controls specific developmental genes in embryonic stem cells

    An NMR-based model to investigate the metabolic phenoreversion of COVID-19 patients throughout a longitudinal study.

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    After SARS-CoV-2 infection, the molecular phenoreversion of the immunological response and its associated metabolic dysregulation are required for a full recovery of the patient. This process is patient-dependent due to the manifold possibilities induced by virus severity, its phylogenic evolution and the vaccination status of the population. We have here investigated the natural history of COVID-19 disease at the molecular level, characterizing the metabolic and immunological phenoreversion over time in large cohorts of hospitalized severe patients (n = 886) and non-hospitalized recovered patients that self-reported having passed the disease (n = 513). Non-hospitalized recovered patients do not show any metabolic fingerprint associated with the disease or immune alterations. Acute patients are characterized by the metabolic and lipidomic dysregulation that accompanies the exacerbated immunological response, resulting in a slow recovery time with a maximum probability of around 62 days. As a manifestation of the heterogeneity in the metabolic phenoreversion, age and severity become factors that modulate their normalization time which, in turn, correlates with changes in the atherogenesis-associated chemokine MCP-1. Our results are consistent with a model where the slow metabolic normalization in acute patients results in enhanced atherosclerotic risk, in line with the recent observation of an elevated number of cardiovascular episodes found in post-COVID-19 cohorts

    Diagnostic potential of the plasma lipidome in infectious disease: application to acute SARS-CoV-2 infection

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    Improved methods are required for investigating the systemic metabolic effects of SARS-CoV-2 infection and patient stratification for precision treatment. We aimed to develop an effective method using lipid profiles for discriminating between SARS-CoV-2 infection, healthy controls, and non-SARS-CoV-2 respiratory infections. Targeted liquid chromatography–mass spectrometry lipid profiling was performed on discovery (20 SARS-CoV-2-positive; 37 healthy controls; 22 COVID-19 symptoms but SARS-CoV-2negative) and validation (312 SARS-CoV-2-positive; 100 healthy controls) cohorts. Orthogonal projection to latent structure-discriminant analysis (OPLS-DA) and Kruskal–Wallis tests were applied to establish discriminant lipids, significance, and effect size, followed by logistic regression to evaluate classification performance. OPLS-DA reported separation of SARS-CoV-2 infection from healthy controls in the discovery cohort, with an area under the curve (AUC) of 1.000. A refined panel of discriminant features consisted of six lipids from different subclasses (PE, PC, LPC, HCER, CER, and DCER). Logistic regression in the discovery cohort returned a training ROC AUC of 1.000 (sensitivity = 1.000, specificity = 1.000) and a test ROC AUC of 1.000. The validation cohort produced a training ROC AUC of 0.977 (sensitivity = 0.855, specificity = 0.948) and a test ROC AUC of 0.978 (sensitivity = 0.948, specificity = 0.922). The lipid panel was also able to differentiate SARS-CoV-2-positive individuals from SARS-CoV-2-negative individuals with COVID-19-like symptoms (specificity = 0.818). Lipid profiling and multivariate modelling revealed a signature offering mechanistic insights into SARS-CoV-2, with strong predictive power, and the potential to facilitate effective diagnosis and clinical management

    A flow cytometry-based neutralization assay for simultaneous evaluation of blocking antibodies against SARS-CoV-2 variants

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    Vaccines against SARS-CoV-2 have alleviated infection rates, hospitalization and deaths associated with COVID-19. In order to monitor humoral immunity, several serology tests have been developed, but the recent emergence of variants of concern has revealed the need for assays that predict the neutralizing capacity of antibodies in a fast and adaptable manner. Sensitive and fast neutralization assays would allow a timely evaluation of immunity against emerging variants and support drug and vaccine discovery efforts. Here we describe a simple, fast, and cell-free multiplexed flow cytometry assay to interrogate the ability of antibodies to prevent the interaction of Angiotensin-converting enzyme 2 (ACE2) and the receptor binding domain (RBD) of the original Wuhan-1 SARS-CoV-2 strain and emerging variants simultaneously, as a surrogate neutralization assay. Using this method, we demonstrate that serum antibodies collected from representative individuals at different time-points during the pandemic present variable neutralizing activity against emerging variants, such as Omicron BA.1 and South African B.1.351. Importantly, antibodies present in samples collected during 2021, before the third dose of the vaccine was administered, do not confer complete neutralization against Omicron BA.1, as opposed to samples collected in 2022 which show significant neutralizing activity. The proposed approach has a comparable performance to other established surrogate methods such as cell-based assays using pseudotyped lentiviral particles expressing the spike of SARS-CoV-2, as demonstrated by the assessment of the blocking activity of therapeutic antibodies (i.e. Imdevimab) and serum samples. This method offers a scalable, cost effective and adaptable platform for the dynamic evaluation of antibody protection in affected populations against variants of SARS-CoV-2.Funding: This research was supported by the SPRI I+D COVID-19 fund (Basque Government, bG-COVID-19), BIOEF EITB Maratoia (BIO21/COV/037 to AP), the European Research Council (ERC) (ERC-2018-StG 804236-NEXTGEN-IO to AP), the Instituto de Salud Carlos iii (ISCiii, DTS21/00094 to AP and DTS20/00138 to MM-C), Ministerio de Ciencia, Innovación y Universidades (MICINN, PID2019-107956RA-I00 and TED2021-129433B-C21 to AP; PID2020-117116RB-I00 and RTC2019-007125-1 to MM-C) and the FERO Foundation to AP. Personal fellowships: EP-F (Juan de la Cierva-Formación, FJC2018-035449-I), ABo (AECC Bizkaia Scientific Foundation, PRDVZ19003BOSC), AG (Programa Bikaintek from the Basque Government, 48-AF-W1-2019-00012), AA-V (La Caixa Inphinit, LCF/BQ/DR20/11790022), BJ-L (Basque Government, PRE_2019_1_0320), ABl (AECC Bizkaia Scientific Foundation, PRDVZ21640DEBL), PV-B (Proyectos I +D+I, PRE2020-092342) and AP (Ramón y Cajal, RYC2018- 024183-I; and Ikerbasque Research Associate). Acknowledgments: The plasmids for the generation of pseudotyped lentiviral particles were kindly provided by Dr Jesse D. Bloom (Fred Hutchinson Cancer Research Center) and Dr Jean-Philippe Julien (The Hospital for Sick Children). HEK293T-ACE2 cells were kindly provided by Dr. June Ereño-Orbea (CIC bioGUNE) and Dr. Jean-Philippe Julien (The Hospital for Sick Children Research Institute, Toronto)
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