1,698 research outputs found

    Functional reduction of SK3-mediated currents precedes AMPA-receptor-mediated excitotoxicity in dopaminergic neurons

    Get PDF
    In primary cultures of mesencephalon small-conductance calcium-activated potassium channels (SK) are expressed in dopaminergic neurons. We characterized SK-mediated currents (ISK) in this system and evaluated their role on homeostasis against excitotoxicity. ISK amplitude was reduced by the glutamatergic agonist AMPA through a reduction in SK channel number in the membrane. Blockade of ISK for 12 h with apamin or NS8593 reduced the number of dopaminergic neurons in a concentration-dependent manner. The effect of apamin was not additive to AMPA toxicity. On the other hand, two ISK agonists,1-EBIO and CyPPA, caused a significant reduction of spontaneous loss of dopaminergic neurons. 1-EBIO reversed the effects of both AMPA and apamin as well. Thus, ISK influences survival and differentiation of dopaminergic neurons in vitro, and is part of protective homeostatic responses, participating in a rapidly acting negative feedback loop coupling calcium levels, neuron excitability and cellular defenses. Fil: Benitez, Bruno A.. Harvard Medical School; Estados UnidosFil: Belálcazar, Helen M.. Harvard Medical School; Estados UnidosFil: Anastasia Gonzalez, Agustin. Washington University in St. Louis; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Mamah, Daniel. Washington University in St. Louis; Estados UnidosFil: Zorumski, Charles. Washington University in St. Louis; Estados UnidosFil: Masco, Daniel Hugo. Washington University in St. Louis; Estados Unidos. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Centro de Biología Celular y Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Herrera, Daniel. Harvard Medical School; Estados UnidosFil: de Erausquin, Gabriel Alejandro. Harvard Medical School; Estados Unido

    Improvements in attention and cardiac autonomic modulation after a 2-weeks sprint interval training program: a fidelity approach

    Get PDF
    This study aimed to: (1) investigate the influence of a 2-weeks sprint interval training (SIT) program on aerobic capacity, cardiac autonomic control, and components of attention in young healthy university students; and (2) to ascertain whether training fidelity would influence these adaptations. One hundred and nine participants were divided into an experimental (EG) and control (CG) groups. The EG performed a SIT program that consisted of 6 sessions of 4 x 30 s "all-out" efforts on a cycle ergometer, interspersed with active rests of 4 min. The criterion for fidelity was achieving >90% of estimated maximum heart rate (HR) during sprint bouts. After analyses, the EG was divided into HIGH (n = 26) and LOW(n = 46) fidelity groups. Components of attention were assessed using the Attention Network Test (ANT). Aerobic capacity (VO(2)max) was estimated while the sum of skinfolds was determined. Autonomic control of HR was assessed by means of HR variability (HRV) and HR complexity at rest and during ANT. Both HIGH and LOW significantly increased aerobic capacity, vagal modulation before and during ANT, and executive control, and decreased body fatness after SIT (p < 0.05). However, only participants from HIGH showed an increase in HR complexity and accuracy in ANT when compared to LOW (p < 0.05). Two weeks of SIT improved executive control, body fatness, aerobic fitness, and autonomic control in university students with better results reported in those individuals who exhibited high fidelity

    First results on light readout from the 1-ton ArDM liquid argon detector for dark matter searches

    Full text link
    ArDM-1t is the prototype for a next generation WIMP detector measuring both the scintillation light and the ionization charge from nuclear recoils in a 1-ton liquid argon target. The goal is to reach a minimum recoil energy of 30\,keVr to detect recoiling nuclei. In this paper we describe the experimental concept and present results on the light detection system, tested for the first time in ArDM on the surface at CERN. With a preliminary and incomplete set of PMTs, the light yield at zero electric field is found to be between 0.3-0.5 phe/keVee depending on the position within the detector volume, confirming our expectations based on smaller detector setups.Comment: 14 pages, 10 figures, v2 accepted for publication in JINS

    Discovery of Two Distant Type Ia Supernovae in the Hubble Deep Field North with the Advanced Camera for Surveys

    Get PDF
    We present observations of the first two supernovae discovered with the recently installed Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. The supernovae were found in Wide Field Camera images of the Hubble Deep Field North taken with the F775W, F850LP, and G800L optical elements as part of the ACS guaranteed time observation program. Spectra extracted from the ACS G800L grism exposures confirm that the objects are Type Ia supernovae (SNe Ia) at redshifts z=0.47 and z=0.95. Follow-up HST observations have been conducted with ACS in F775W and F850LP and with NICMOS in the near-infrared F110W bandpass, yielding a total of 9 flux measurements in the 3 bandpasses over a period of 50 days in the observed frame. We discuss many of the important issues in doing accurate photometry with the ACS. We analyze the multi-band light curves using two different fitting methods to calibrate the supernovae luminosities and place them on the SNe Ia Hubble diagram. The resulting distances are consistent with the redshift-distance relation of the accelerating universe model, although evolving intergalactic grey dust remains as a less likely possibility. The relative ease with which these SNe Ia were found, confirmed, and monitored demonstrates the potential ACS holds for revolutionizing the field of high-redshift SNe Ia, and therefore of testing the accelerating universe cosmology and constraining the "epoch of deceleration".Comment: 11 pages, 8 embedded figures. Accepted for publication in Ap

    The Contribution of Halos with Different Mass Ratios to the Overall Growth of Cluster-Sized Halos

    Get PDF
    We provide a new observational test for a key prediction of the \Lambda CDM cosmological model: the contributions of mergers with different halo-to-main-cluster mass ratios to cluster-sized halo growth. We perform this test by dynamically analyzing seven galaxy clusters, spanning the redshift range 0.13<zc<0.450.13 < z_c < 0.45 and caustic mass range 0.41.50.4-1.5 1015h0.73110^{15} h_{0.73}^{-1} M_{\odot}, with an average of 293 spectroscopically-confirmed bound galaxies to each cluster. The large radial coverage (a few virial radii), which covers the whole infall region, with a high number of spectroscopically identified galaxies enables this new study. For each cluster, we identify bound galaxies. Out of these galaxies, we identify infalling and accreted halos and estimate their masses and their dynamical states. Using the estimated masses, we derive the contribution of different mass ratios to cluster-sized halo growth. For mass ratios between ~0.2 and ~0.7, we find a ~1 σ\sigma agreement with \Lambda CDM expectations based on the Millennium simulations I and II. At low mass ratios, 0.2\lesssim 0.2, our derived contribution is underestimated since the detection efficiency decreases at low masses, 2×1014\sim 2 \times 10^{14} h0.731h_{0.73}^{-1} M_{\odot}. At large mass ratios, 0.7\gtrsim 0.7, we do not detect halos probably because our sample, which was chosen to be quite X-ray relaxed, is biased against large mass ratios. Therefore, at large mass ratios, the derived contribution is also underestimated.Comment: 25 pages, 16 figures, 6 tables, 2 machine readable tables, accepted for publication in ApJ, updated acknowledgements and data table format modifications mad

    Palabra escrita y poder. La biblioteca del convento franciscano de Córdoba del Tucumán. (Siglos XVII Y XVIII)

    Get PDF
    El objeto de este proyecto es el estudio de la biblioteca del convento franciscano de Córdoba del Tucumán entre los siglos XVII y XVIII, a través de los únicos inventarios patrimoniales de sus libros, el primero redactado en 1726 y el segundo en 1815. La rareza y riqueza de la fuente hallada, muy poco común para la ciudad y otros espacios de Argentina, amerita el estudio de la circulación y posesión del libro, así como de la conformación de uno de los acervos coloniales bibliográficos más importantes de los entonces Tucumán, Paraguay y Río de la Plata, después de la Librería Grande del Colegio Máximo de la Compañía de Jesús de Córdoba.Fil: Benito Moya, Silvano G. A. Universidad Católica de Córdoba; Facultad de Filosofía y Humanidades; Argentin

    From face-to-face to virtuality in pandemic times: the experience of the hospital italiano de Buenos Aires

    Get PDF
    El 11 de marzo de 2020, la Organización Mundial de la Salud (OMS) declaró el COVID-19 como pandemia, afectando drásticamente la atención de la salud. A nivel global se adoptaron medidas como el distanciamiento social y la cuarentena. Ello representó un enorme desafío para los Sistemas de Información en Salud (SIS), que rápidamente debieron adaptarse, frente a una razón ineludible para abrazar por completo la transformación digital. Surge la necesidad de explorar las tecnologías digitales utilizadas durante la pandemia y considerarlas para su uso continuadoen el tiempo o cíclicamente en caso de brotes recurrentes. Las herramientas informáticas se han utilizado para la prestación de servicios de telemedicina, monitorización remota de pacientes, comunicación digital entre líderes políticos y autoridades científicas, monitorización de datos paraanalizar la propagación y evolución del COVID-19, etc. Los países y organizaciones han impulsado el uso de soluciones tecnológicas con distintas limitaciones. El Hospital Italiano de Buenos Aires posee una trayectoria de más de 20 años en implementaciones e innovaciones tecnológicas; sinembargo, la pandemia impulsó una serie de adaptaciones en su SIS. El objetivo de este trabajo fue describir dicho proceso de adaptación digital desde marzo a diciembre de 2020, e identificar los principales resultados utilizando un modelo sociotécnico. Se empleó el modelo de Sittig queincluye 8 dimensiones: Infraestructura, Contenido clínico, Interfaz Humano-computadora, Personas, Comunicación y procesos, Regulaciones, Características organizacionales y Políticas internas y Medición y monitorización.On March 11, 2020, the World Health Organization (WHO) declared COVID-19 a pandemic, dramatically affecting health care. Measures such as social distancing and quarantine were adopted globally. This new context represented a huge challenge for Health Information Systems (HIS) that had to adapt quickly, facing an inescapable reason to fully embrace the digital transformation. There is a need to explore the digital technologies used during the pandemic and consider them for continued use over time or cyclically in the event of recurring outbreaks. Digital tools have been used for the provision of telemedicine services, remote patient monitoring, digital communication between political leaders and scientific authorities, data monitoring to analyze the spread and evolution of COVID-19, etc. Countries and organizations have promoted the use of technological solutions with different limitations. The Hospital Italiano de Buenos Aires has a history of more than 20 years in technological implementations and innovations, however, the pandemic prompted a series of adaptations in its SIS. The objective of this work was to describe said digital adaptation process from March to December 2020, and to identify the main results using a sociotechnical model. Sittig´model was used, which includes 8 dimensions: Infrastructure, Clinical Content, Human-Computer Interface, People, Communication and Processes, Regulations, Organizational Characteristics and Internal Policies, and Measurement and Monitoring.Fil: Giménez, Cintia L.. Hospital Italiano; ArgentinaFil: Rabinovich, Diego A.. Hospital Italiano; ArgentinaFil: Colussi, Giuliana C.. Hospital Italiano; ArgentinaFil: Otero, Carlos Martin. Hospital Italiano; ArgentinaFil: Plazzotta, Fernando. Hospital Italiano; ArgentinaFil: Benitez, Sonia Elizabeth. Hospital Italiano; ArgentinaFil: Luna, Daniel Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional e Ingeniería Biomédica - Hospital Italiano. Instituto de Medicina Traslacional e Ingeniería Biomédica.- Instituto Universitario Hospital Italiano de Buenos Aires. Instituto de Medicina Traslacional e Ingeniería Biomédica; Argentin

    The HYLAN M Study: Efficacy of 0.15% High Molecular Weight Hyaluronan Fluid in the Treatment of Severe Dry Eye Disease in a Multicenter Randomized Trial

    Get PDF
    The aim of the HYLAN M study was to investigate if symptoms and/or signs of patients suffering from severe dry eye disease (DED) can be improved by substituting individually optimized artificial tear therapy by high molecular weight hyaluronan (HMWHA) eye drops. In this international, multicenter study, patients with symptoms of at least ocular surface disease index (OSDI) 33 and corneal fluorescein staining (CFS) of at least Oxford grade 3 were included. A total of 84 per-protocol patients were randomized in two study arms. The control group continued to use their individual optimum artificial tears over the study period of eight weeks; in the verum group, the artificial tears were substituted by eye drops containing 0.15% HMWHA. At the week 8 visit, the average OSDI of the verum group had improved by 13.5 as compared to the control group (p = 0.001). The best corrected visual acuity (BCVA) had improved by 0.04 logMAR (p = 0.033). CFS, tear film break-up time (TBUT), Schirmer I, lid wiper epitheliopathy (LWE), mucocutaneous junction (Yamaguchi score), and tear osmolarity were not significantly different between the verum and control groups (p > 0.050). We conclude that for most patients with severe DED, 0.15% HMWHA eye drops provide excellent improvement of symptoms without impairment of dry eye signs
    corecore