126 research outputs found

    Material characterization and functional implications of a Claude Laurent Glass Flute

    Full text link
    The Claude Laurent glass flutes (1805–1844) are singular elements that contributed to the transformation of musical instruments through the introduction of new styles and technologies. These flutes combine improved technical capabilities with aesthetic criteria, making them high-quality instruments and appreciated objects of art. Through the analysis of an 1823 flute, the present study is focused on the determination of their material characteristics and the relationship of these materials with the flute's structure and constructive process. The composition of the glass and metallic parts has been determined by XRF after establishing a specific calibration for each material and energy range. A potash-lime-silica glass, which shows similar composition to some previously analysed flutes conserved at the Library of Congress in Washington, was used for the glass parts of the flute. Composition of the metallic parts of a Laurent flute is presented for the first time. Regarding the larger parts, four different composition groups can be distinguished. The composition established can yield information about the constructive process and can be related to the function of each group. For example, a silver-copper alloy serving aesthetic reasons was used for all visible metallic parts, while hidden parts that demand higher mechanical resistance were made with bronze. Regarding the flute's smaller metallic parts, which consist of the keys and key levers and some mechanical pieces, such as screws or springs, the materials detected include a silver-copper alloy and steel

    Gestión y estrategias de la empresa Baldwin en el simulador de negocios Capstone

    Get PDF
    En este documento se describe el desempeño de la empresa Baldwin, la estrategia y los resultados obtenidos en ocho períodos del simulador de negocios CAPSTONE. En el primer capítulo se aborda el marco teórico donde se desarrollan conceptos de estrategia, mercadotecnia, competencia e industria y se sientan las bases para la planeación estratégica presentada en el segundo capítulo. Los capítulos del tres al seis describen las decisiones tomadas en los departamentos de investigación y desarrollo, mercadotecnia y recursos humanos, así como el desempeño de la empresa a lo largo de los ocho periodos simulados. Cada capítulo comprende un periodo que consta de dos años de operaciones. Finalmente, el capítulo siete expone las conclusiones de los cuatro miembros del equipo respecto a los resultados de la simulación

    Evidence for sexual difference in astrocytes of adult rat hippocampus

    Get PDF
    Abstract We quantified the number of glial fibrillary acidic protein immunoreactive (GFAP-IR) astrocytes in the CA1 and CA3 areas of the adult rat hippocampus. The dorsal and ventral regions of the hippocampus were taken into account to estimate the GFAP-IR cells using unbiased stereological techniques. Males had a higher number of GFAP-IR astrocytes in the CA3 area, whereas females had more in the CA1 area. No sex difference was found between dorsal and ventral regions, although most GFAP-IR astrocytes were located in the dorsal hippocampus. q 2003 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Glial fibrillary acidic protein; Hippocampus; Sex differences; Optical fractionator; Astrocytes; Rat The hippocampus represents a heterogeneous structure, functionally differentiated along its dorsoventral axis as recent behavioural studies suggest However, not only neurons but also glial cells are targets for sex hormones such as estrogen and testosterone The aim of the present study was to evaluate gender differences in the total number of GFAP-immunoreactive (GFAP-IR) astrocytes in CA1 and CA3 hippocampal areas, estimated by unbiased stereological counting methods. In particular, the dorsoventral anatomical subdivision of these hippocampal areas was taken into account. Adult male and female Wistar rats (3 months of age, n ¼ 6 per group) obtained from the University of Oviedo central vivarium were used. The animals were maintained on a 12:12 h light/dark cycle, and a temperature of 22^2 8C, with food and water available ad libitum. All experimental procedures followed strictly the EEC Council Directive 86/609 regarding the care and use of laboratory animals. Vaginal smears were taken from virgin females to determine the different stages of the estrous cycle. The subjects were selected at the morning of the proestrous phase. This arbitrary criterion was primarily chosen to avoid unpredictable variations in the results due to different levels of sex steroids in circulation. The rats were anaesthetized with sodium pentobarbital (70 mg/kg for males and 45 mg/kg for females, i.p.) and intracardially perfused with 0.9% saline in 0.1 M phosphate buffer (PBS; pH 7.4) followed by 10% phosphate-buffered 0304-3940/03/$ -see front matter

    The anti-aging factor Klotho protects against acquired long QT syndrome induced by uremia and promoted by fibroblast growth factor 23

    Get PDF
    [Background]: Chronic kidney disease (CKD) is associated with increased propensity for arrhythmias. In this context, ventricular repolarization alterations have been shown to predispose to fatal arrhythmias and sudden cardiac death. Between mineral bone disturbances in CKD patients, increased fibroblast growth factor (FGF) 23 and decreased Klotho are emerging as important effectors of cardiovascular disease. However, the relationship between imbalanced FGF23-Klotho axis and the development of cardiac arrhythmias in CKD remains unknown. [Methods]: We carried out a translational approach to study the relationship between the FGF23–Klotho signaling axis and acquired long QT syndrome in CKD-associated uremia. FGF23 levels and cardiac repolarization dynamics were analyzed in patients with dialysis-dependent CKD and in uremic mouse models of 5/6 nephrectomy (Nfx) and Klotho deficiency (hypomorphism), which show very high systemic FGF23 levels. [Results]: Patients in the top quartile of FGF23 levels had a higher occurrence of very long QT intervals (> 490 ms) than peers in the lowest quartile. Experimentally, FGF23 induced QT prolongation in healthy mice. Similarly, alterations in cardiac repolarization and QT prolongation were observed in Nfx mice and in Klotho hypomorphic mice. QT prolongation in Nfx mice was explained by a significant decrease in the fast transient outward potassium (K+) current (Itof), caused by the downregulation of K+ channel 4.2 subunit (Kv4.2) expression. Kv4.2 expression was also significantly reduced in ventricular cardiomyocytes exposed to FGF23. Enhancing Klotho availability prevented both long QT prolongation and reduced Itof current. Likewise, administration of recombinant Klotho blocked the downregulation of Kv4.2 expression in Nfx mice and in FGF23-exposed cardiomyocytes. [Conclusion]: The FGF23–Klotho axis emerges as a new therapeutic target to prevent acquired long QT syndrome in uremia by minimizing the predisposition to potentially fatal ventricular arrhythmias and sudden cardiac death in patients with CKD.This work was supported by projects from the Instituto de Salud Carlos III, Ministry of Economy, Industry and Competitiveness (PI17/01093, PI17/01193, PI20/00763, CP15/00129, F18/00261, CPII20/00022, SAF2017-84777-R, PID2020-113238RB-I00), from the Sociedad Española de Cardiología (SEC), and from the Fundación Renal Íñigo Alvarez de Toledo (FRIAT), co-funded by the European Regional Development Fund (Fondos FEDER)

    Study and characterization of global solar radiation and incident UV in the city of Leon, Guanajuato, Mexico

    Get PDF
    Controlled sun exposure can greatly benefit vitamin D synthesis, however, irresponsible sun exposure can cause considerable biological damage. Among the extraterrestrial solar radiation that reaches the earth's surface, UV rays are characterized by having the shortest wavelengths (less than 400 nm) and the highest frequencies, which is why they concentrate a large amount of energy. In particular, radiation with wavelengths less than 300 nm can alter DNA molecules and cause biological damage such as skin changes, cataracts, possible mutations, immunosuppression, photoaging and many other conditions. Therefore, this research estimates the global solar radiation and the incident daily UV radiation, as well as the UV index in order to identify the possible dose of absorbed radiation and consequently identify the relevant protection actions for the local population

    Mobile Communication 2012 : Experiències i recerques sobre comunicació mòbil

    Get PDF
    La comunicació mòbil és un dels temes de més actualitat en diferents fòrums, des de diferents perspectives. Espanya juga un paper important per les dinàmiques i l’evolució del seu mercat. En aquest sentit, el nostre país ofereix un interès específic per l'amplitud del seu parc de dispositius 3G (el segon d'Europa, després d'Itàlia) i per la intensitat del desenvolupament de xarxes socials mòbils, a més de per la creixent implicació d'empreses en la producció i distribució de continguts mòbils. Com va passar amb Internet, es tracta d’un procés d'innovació pel qual els formats de contingut, les pràctiques de consum i els models de negoci característics de la televisió i la xarxa, per exemple, s'adapten, primer, al nou mitjà, per a després desenvolupar formes i models específics que aprofiten les potencialitats de personalització, geolocalització i conectivitat ubiqua

    First computational design using lambda-superstrings and in vivo validation of SARS-CoV-2 vaccine

    Get PDF
    Coronavirus disease 2019 (COVID-19) is the greatest threat to global health at the present time, and considerable public and private effort is being devoted to fighting this recently emerged disease. Despite the undoubted advances in the development of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, uncertainty remains about their future efficacy and the duration of the immunity induced. It is therefore prudent to continue designing and testing vaccines against this pathogen. In this article we computationally designed two candidate vaccines, one monopeptide and one multipeptide, using a technique involving optimizing lambda-superstrings, which was introduced and developed by our research group. We tested the monopeptide vaccine, thus establishing a proof of concept for the validity of the technique. We synthesized a peptide of 22 amino acids in length, corresponding to one of the candidate vaccines, and prepared a dendritic cell (DC) vaccine vector loaded with the 22 amino acids SARS-CoV-2 peptide (positions 50-71) contained in the NTD domain (DC-CoVPSA) of the Spike protein. Next, we tested the immunogenicity, the type of immune response elicited, and the cytokine profile induced by the vaccine, using a non-related bacterial peptide as negative control. Our results indicated that the CoVPSA peptide of the Spike protein elicits noticeable immunogenicity in vivo using a DC vaccine vector and remarkable cellular and humoral immune responses. This DC vaccine vector loaded with the NTD peptide of the Spike protein elicited a predominant Th1-Th17 cytokine profile, indicative of an effective anti-viral response. Finally, we performed a proof of concept experiment in humans that included the following groups: asymptomatic non-active COVID-19 patients, vaccinated volunteers, and control donors that tested negative for SARS-CoV-2. The positive control was the current receptor binding domain epitope of COVID-19 RNA-vaccines. We successfully developed a vaccine candidate technique involving optimizing lambda-superstrings and provided proof of concept in human subjects. We conclude that it is a valid method to decipher the best epitopes of the Spike protein of SARS-CoV-2 to prepare peptide-based vaccines for different vector platforms, including DC vaccines.Luis Martínez and Iker Malaina were supported by the Basque Government, grants IT974-16 and KK-2018/00090 and by the UPV/EHU and Basque Center of Applied Mathematics, grants US18/21 and US21/27. Carmen Alvarez-Dominguez was funded by the Instituto de Salud Carlos III, grants DTS18-00022 and PI19-01580, co-funded in part with European FEDER funds “A new way of making Europe”, the Instituto de Investigación Marqués de Valdecilla, grant INNVAL20/01, and the COST European action ENOVA CA-16231. David Salcines-Cuevas was supported by a predoctoral contract for the BioHealth research program of the Cantabria government. Hector Teran-Navarro salary was supported by the Instituto de Investigación Marqués de Valdecilla, grant INNVAL19/26. Andrea Zeoli was an Erasmus student from the University of Milan “La Statale” (Milan, Italy) performing a stay at IDIVAL.Peer reviewe
    corecore