15 research outputs found
Introducción al grupo de R. Thompson
El trabajo es una breve introducción al grupo de R.Thompson. En el cual se estudiarán las propiedades básicas del grupo, así coo algunos de sus subgrupos.Comenzaremos por la descripción del grupo y la relación de sus elementos y los árboles binarios. También estudiaremos la extensión de los elementos del grupo a la recta real.Posteriormente buscaremos presentaciones del mismo, comenzaremos por una presentación finita, pero al final del segundo capítulo hallaremos de manera explícita una representación finita.Al final del mismo trabajaremos algunas propiedades importantes de F, utilizando los resultados que se han visto a lo largo del trabajo. Se presentará además e grupo de Highman, una nueva construcción a partir del grupo de Thompson, estudiaremos alguna de sus propiedades más básicas, así como la importancia de este grupo.<br /
Estudi de les aigües salines a la conca del riu Llobregat i Cardener : implicacions ambientals
L'increment de la salinitat a les aigües subterrànies a prop de la zones de les explotacions mineres salines representa un problema ambiental amb moltes implicacions socio-econòmiques. La part mitja de la conca del riu Llobregat i Cardener és un clar exemple d'aquesta problemàtica. En molts casos l'origen de la salinitat és dubtós, ja que pot provenir del contacte de l'aigua de l'aqüífer amb formacions geològiques salines naturals o per l'afectació de les escombreres produïdes per l'explotació minera de potasses que es troba en aquesta regió. L'objectiu d'aquest treball és demostrar que el Ra pot ser un bon traçador per determinar l'origen de la salinitat de les aigües i complementar les analítiques químiques elementals i dels isòtops del sofre i de l'oxigen del sulfat (δ34SSO4 i δ18OSO4). La presència dels diversos isòtops del Ra en les aigües subterrànies dependrà de la geologia i del temps de residència de l'aigua dins l'aqüífer. L'anàlisi de 12 mostres de la comarca indica que el 226Ra és el millor dels isòtops del Ra que permet diferenciar l'origen de les aigües subterrànies.El incremento de la salinidad en las aguas subterráneas cerca de la zonas de las explotaciones mineras salinas representa un problema ambiental con muchas implicaciones socioeconómicas. La parte media de la cuenca del río Llobregat y Cardener es un claro ejemplo de esta problemática. En muchos casos el origen de la salinidad es dudoso, ya que puede provenir del contacto del agua del acuífero con formaciones geológicas salinas naturales o por la afectación de las escombreras producidas por la explotación minera de potasa que se encuentra en esta región. El objetivo de este trabajo es demostrar que el Ra puede ser un buen trazador para determinar el origen de la salinidad de las aguas y complementar las analíticas químicas elementales y los isótopos del azufre y del oxígeno del sulfato (δ34SSO4 i δ18OSO4). La presencia de los diversos isótopos del Ra en las aguas subterráneas dependerá de la geología y del tiempo de residencia del agua dentro del acuífero. El análisis de 12 muestras de la comarca indica que el 226Ra es el mejor de los isótopos del Ra que permite diferenciar el origen de las aguas subterráneas.The increased salinity in groundwater near the areas of mining salt is a problem with many environmental socio-economic implications. The middle section of the Llobregat and Cardoner river basin is a clear example of this problem. The origin of the salinity is controversial, as it can be related to natural interaction with saline formations, or it could be caused from potash mine tailing in this region. The aim of this paper is to show that Ra is a good tracer to determine the origin of the salinity of the water and complement chemical analyzes and sulphur isotopes of oxygen and sulfate (δ34SSO4 & δ18OSO4). The presence of different isotopes of Ra in groundwater depends on the geology and the residence time of water in the aquifer. The analysis of 12 samples from the region indicates that 226Rn is the best of the Ra isotopes that can discern the origin of groundwater
Nitrogen and oxygen isotopes of dissolved nitrate to evaluate the efficiency of induced groundwater denitrification at field-scale
Nitrate, pollutants, denitrification, nitrate vulnerable zones, stable isotopes
Elevated α-Ketoglutaric Acid Concentrations and a Lipid-Balanced Signature Are the Key Factors in Long-Term HIV Control
Long-term elite controllers (LTECs) are a fascinating small subset of HIV individuals with viral and immunological HIV control in the long term that have been designated as models of an HIV functional cure. However, data on the LTEC phenotype are still scarce, and hence, the metabolomics and lipidomics signatures in the LTEC-extreme phenotype, LTECs with more than 10 years of viral and immunological HIV control, could be pivotal to finding the keys for functional HIV remission. Metabolomics and lipidomics analyses were performed using high-resolution mass spectrometry (ultra-high-performance liquid chromatography-electrospray ionization-quadrupole time of flight [UHPLC-(ESI) qTOF] in plasma samples of 13 patients defined as LTEC-extreme, a group of 20 LTECs that lost viral and/or immunological control during the follow-up study (LTEC-losing) and 9 EC patients with short-term viral and immunological control (less than 5 years; no-LTEC patients). Long-term viral and immunological HIV-1 control was found to be strongly associated with elevated tricarboxylic acid (TCA) cycle function. Interestingly, of the nine metabolites identified in the TCA cycle, α-ketoglutaric acid (p = 0.004), a metabolite implicated in the activation of the mTOR complex, a modulator of HIV latency and regulator of several biological processes, was found to be a key metabolite in the persistent control. On the other hand, a lipidomics panel combining 45 lipid species showed an optimal percentage of separation and an ability to differentiate LTEC-extreme from LTEC-losing, revealing that an elevated lipidomics plasma profile could be a predictive factor for the reignition of viral replication in LTEC individuals.This work was supported by the Fondo de Investigación Sanitaria [PI13/0796, PI16/00503, PI16/0684, PI18/1532, PI19/00004, PI19/01127, PI19/01337 PI16/001769, PI19/00973, and PI20/00326]-ISCIII-FEDER (co-funded by the European Regional Development Fund/European Social Fund; “A way to make Europe”/”Investing in your future”); Programa de Suport als Grups de Recerca AGAUR (2017SGR948); Gilead Fellowship Program GLD14/293; The SPANISH AIDS Research Network [RD16/0002/0001, RD16/0002/0002, RD16/0025/0006, RD16/0025/0013, and RD16/0025/0020]-ISCIII-FEDER (Spain); and the Centro de Investigación Biomédica en Red de Enfermedades Infecciosas-ISCIII [CB21/13/00015, CB21/13/00020, and CB21/13/00044], Madrid, Spain. JM is supported by the Universitat Rovira I Virgili under grant agreement “2019PMF-PIPF-18,” through the call “Martí Franquès Research Fellowship Programme.” NR is a Miguel Servet researcher from the ISCIII [CPII19/00025]. EY is supported by the Instituto de Salud Carlos III (ISCIII) under grant agreement “FI20/0011800” through the program “Contratos Predoctorales de Formación en Investigación en Salud.” ER-M was supported by the Spanish National Research Council (CSIC). FV is supported by grants from the Programa de Intensificación de Investigadores (INT20/00031)-ISCIII and by “Premi a la Trajectòria Investigadora als Hospitals de l’ICS 2018.” AR is supported by IISPV through the project “2019/IISPV/05” (Boosting Young Talent), by GeSIDA through the “III Premio para Jóvenes Investigadores 2019,” and by the Instituto de Salud Carlos III (ISCIII) under grant agreement “CP19/00146” through the Miguel Servet Program.S
Epidemiological trends of HIV/HCV coinfection in Spain, 2015-2019
Altres ajuts: Spanish AIDS Research Network; European Funding for Regional Development (FEDER).Objectives: We assessed the prevalence of anti-hepatitis C virus (HCV) antibodies and active HCV infection (HCV-RNA-positive) in people living with HIV (PLWH) in Spain in 2019 and compared the results with those of four similar studies performed during 2015-2018. Methods: The study was performed in 41 centres. Sample size was estimated for an accuracy of 1%. Patients were selected by random sampling with proportional allocation. Results: The reference population comprised 41 973 PLWH, and the sample size was 1325. HCV serostatus was known in 1316 PLWH (99.3%), of whom 376 (28.6%) were HCV antibody (Ab)-positive (78.7% were prior injection drug users); 29 were HCV-RNA-positive (2.2%). Of the 29 HCV-RNA-positive PLWH, infection was chronic in 24, it was acute/recent in one, and it was of unknown duration in four. Cirrhosis was present in 71 (5.4%) PLWH overall, three (10.3%) HCV-RNA-positive patients and 68 (23.4%) of those who cleared HCV after anti-HCV therapy (p = 0.04). The prevalence of anti-HCV antibodies decreased steadily from 37.7% in 2015 to 28.6% in 2019 (p < 0.001); the prevalence of active HCV infection decreased from 22.1% in 2015 to 2.2% in 2019 (p < 0.001). Uptake of anti-HCV treatment increased from 53.9% in 2015 to 95.0% in 2019 (p < 0.001). Conclusions: In Spain, the prevalence of active HCV infection among PLWH at the end of 2019 was 2.2%, i.e. 90.0% lower than in 2015. Increased exposure to DAAs was probably the main reason for this sharp reduction. Despite the high coverage of treatment with direct-acting antiviral agents, HCV-related cirrhosis remains significant in this population
Spatiotemporal Characteristics of the Largest HIV-1 CRF02_AG Outbreak in Spain: Evidence for Onward Transmissions
Background and Aim: The circulating recombinant form 02_AG (CRF02_AG) is the predominant clade among the human immunodeficiency virus type-1 (HIV-1) non-Bs with a prevalence of 5.97% (95% Confidence Interval-CI: 5.41–6.57%) across Spain. Our aim was to estimate the levels of regional clustering for CRF02_AG and the spatiotemporal characteristics of the largest CRF02_AG subepidemic in Spain.Methods: We studied 396 CRF02_AG sequences obtained from HIV-1 diagnosed patients during 2000–2014 from 10 autonomous communities of Spain. Phylogenetic analysis was performed on the 391 CRF02_AG sequences along with all globally sampled CRF02_AG sequences (N = 3,302) as references. Phylodynamic and phylogeographic analysis was performed to the largest CRF02_AG monophyletic cluster by a Bayesian method in BEAST v1.8.0 and by reconstructing ancestral states using the criterion of parsimony in Mesquite v3.4, respectively.Results: The HIV-1 CRF02_AG prevalence differed across Spanish autonomous communities we sampled from (p < 0.001). Phylogenetic analysis revealed that 52.7% of the CRF02_AG sequences formed 56 monophyletic clusters, with a range of 2–79 sequences. The CRF02_AG regional dispersal differed across Spain (p = 0.003), as suggested by monophyletic clustering. For the largest monophyletic cluster (subepidemic) (N = 79), 49.4% of the clustered sequences originated from Madrid, while most sequences (51.9%) had been obtained from men having sex with men (MSM). Molecular clock analysis suggested that the origin (tMRCA) of the CRF02_AG subepidemic was in 2002 (median estimate; 95% Highest Posterior Density-HPD interval: 1999–2004). Additionally, we found significant clustering within the CRF02_AG subepidemic according to the ethnic origin.Conclusion: CRF02_AG has been introduced as a result of multiple introductions in Spain, following regional dispersal in several cases. We showed that CRF02_AG transmissions were mostly due to regional dispersal in Spain. The hot-spot for the largest CRF02_AG regional subepidemic in Spain was in Madrid associated with MSM transmission risk group. The existence of subepidemics suggest that several spillovers occurred from Madrid to other areas. CRF02_AG sequences from Hispanics were clustered in a separate subclade suggesting no linkage between the local and Hispanic subepidemics
Estudi de les aigües salines a la conca del riu Llobregat i Cardener : implicacions ambientals
L'increment de la salinitat a les aigües subterrànies a prop de la zones de les explotacions mineres salines representa un problema ambiental amb moltes implicacions socio-econòmiques. La part mitja de la conca del riu Llobregat i Cardener és un clar exemple d'aquesta problemàtica. En molts casos l'origen de la salinitat és dubtós, ja que pot provenir del contacte de l'aigua de l'aqüífer amb formacions geològiques salines naturals o per l'afectació de les escombreres produïdes per l'explotació minera de potasses que es troba en aquesta regió. L'objectiu d'aquest treball és demostrar que el Ra pot ser un bon traçador per determinar l'origen de la salinitat de les aigües i complementar les analítiques químiques elementals i dels isòtops del sofre i de l'oxigen del sulfat (δ34SSO4 i δ18OSO4). La presència dels diversos isòtops del Ra en les aigües subterrànies dependrà de la geologia i del temps de residència de l'aigua dins l'aqüífer. L'anàlisi de 12 mostres de la comarca indica que el 226Ra és el millor dels isòtops del Ra que permet diferenciar l'origen de les aigües subterrànies.El incremento de la salinidad en las aguas subterráneas cerca de la zonas de las explotaciones mineras salinas representa un problema ambiental con muchas implicaciones socioeconómicas. La parte media de la cuenca del río Llobregat y Cardener es un claro ejemplo de esta problemática. En muchos casos el origen de la salinidad es dudoso, ya que puede provenir del contacto del agua del acuífero con formaciones geológicas salinas naturales o por la afectación de las escombreras producidas por la explotación minera de potasa que se encuentra en esta región. El objetivo de este trabajo es demostrar que el Ra puede ser un buen trazador para determinar el origen de la salinidad de las aguas y complementar las analíticas químicas elementales y los isótopos del azufre y del oxígeno del sulfato (δ34SSO4 i δ18OSO4). La presencia de los diversos isótopos del Ra en las aguas subterráneas dependerá de la geología y del tiempo de residencia del agua dentro del acuífero. El análisis de 12 muestras de la comarca indica que el 226Ra es el mejor de los isótopos del Ra que permite diferenciar el origen de las aguas subterráneas.The increased salinity in groundwater near the areas of mining salt is a problem with many environmental socio-economic implications. The middle section of the Llobregat and Cardoner river basin is a clear example of this problem. The origin of the salinity is controversial, as it can be related to natural interaction with saline formations, or it could be caused from potash mine tailing in this region. The aim of this paper is to show that Ra is a good tracer to determine the origin of the salinity of the water and complement chemical analyzes and sulphur isotopes of oxygen and sulfate (δ34SSO4 & δ18OSO4). The presence of different isotopes of Ra in groundwater depends on the geology and the residence time of water in the aquifer. The analysis of 12 samples from the region indicates that 226Rn is the best of the Ra isotopes that can discern the origin of groundwater
Elevated α-Ketoglutaric Acid Concentrations and a Lipid-Balanced Signature Are the Key Factors in Long-Term HIV Control
Long-term elite controllers (LTECs) are a fascinating small subset of HIV individuals with viral and immunological HIV control in the long term that have been designated as models of an HIV functional cure. However, data on the LTEC phenotype are still scarce, and hence, the metabolomics and lipidomics signatures in the LTEC-extreme phenotype, LTECs with more than 10 years of viral and immunological HIV control, could be pivotal to finding the keys for functional HIV remission. Metabolomics and lipidomics analyses were performed using high-resolution mass spectrometry (ultra-high-performance liquid chromatography-electrospray ionization-quadrupole time of flight [UHPLC-(ESI) qTOF] in plasma samples of 13 patients defined as LTEC-extreme, a group of 20 LTECs that lost viral and/or immunological control during the follow-up study (LTEC-losing) and 9 EC patients with short-term viral and immunological control (less than 5 years; no-LTEC patients). Long-term viral and immunological HIV-1 control was found to be strongly associated with elevated tricarboxylic acid (TCA) cycle function. Interestingly, of the nine metabolites identified in the TCA cycle, α-ketoglutaric acid (p = 0.004), a metabolite implicated in the activation of the mTOR complex, a modulator of HIV latency and regulator of several biological processes, was found to be a key metabolite in the persistent control. On the other hand, a lipidomics panel combining 45 lipid species showed an optimal percentage of separation and an ability to differentiate LTEC-extreme from LTEC-losing, revealing that an elevated lipidomics plasma profile could be a predictive factor for the reignition of viral replication in LTEC individuals
Impact of late presentation of HIV infection on short-, mid- and long-term mortality and causes of death in a multicenter national cohort : 2004-2013
To analyze the impact of late presentation (LP) on overall mortality and causes of death and describe LP trends and risk factors (2004-2013). Cox models and logistic regression were used to analyze data from a nation-wide cohort in Spain. LP is defined as being diagnosed when CD4 < 350 cells/ml or AIDS. Of 7165 new HIV diagnoses, 46.9% (CI:45.7-48.0) were LP, 240 patients died.First-year mortality was the highest (aHR = 10.3[CI:5.5-19.3]); between 1 and 4 years post-diagnosis, aHR = 1.9(1.2-3.0); an
Discovering HIV related information by means of association rules and machine learning
Acquired immunodeficiency syndrome (AIDS) is still one of the main health problems worldwide. It is therefore essential to keep making progress in improving the prognosis and quality of life of affected patients. One way to advance along this pathway is to uncover connections between other disorders associated with HIV/AIDS-so that they can be anticipated and possibly mitigated. We propose to achieve this by using Association Rules (ARs). They allow us to represent the dependencies between a number of diseases and other specific diseases. However, classical techniques systematically generate every AR meeting some minimal conditions on data frequency, hence generating a vast amount of uninteresting ARs, which need to be filtered out. The lack of manually annotated ARs has favored unsupervised filtering, even though they produce limited results. In this paper, we propose a semi-supervised system, able to identify relevant ARs among HIV-related diseases with a minimal amount of annotated training data. Our system has been able to extract a good number of relationships between HIV-related diseases that have been previously detected in the literature but are scattered and are often little known. Furthermore, a number of plausible new relationships have shown up which deserve further investigation by qualified medical experts