258 research outputs found

    Programas de adultos mayores en Chile con ejercicio físico : una revisión de la literatura

    Get PDF
    Tesis (Kinesiólogo)La población de adulto mayor (AM) en el mundo es cada vez mayor, hecho que no escapa a Chile. Uno de los grandes retos a los que se enfrenta el país es el cuidado y mantención de los AM, por lo que durante las últimas dos décadas se han creado un grupo de programas dirigidos hacia ellos. Nuestra investigación aborda los distintos programas dirigidos a los AM que contienen el ejercicio físico como eje esencial, ya que está demostrado que éste ayuda a minimizar los factores de riesgo de enfermedades cardiovasculares (ECV), principal causa de muerte tanto a nivel nacional como mundial. ( A través de una búsqueda bibliográfica de estos programas, detectamos dos grandes problemas: por un lado, la descripción de los trabajos específicos a realizar es casi nula, quedando en manos del profesional de turno la planificación de los ejercicios. Por otro lado, la cantidad de los programas es muy baja, obteniendo una muestra de solo tres programas. Dada la importancia del ejercicio físico en los AM, sostenemos que es de suma importancia trabajar más y mejor en estos programas, ya que con ellos se puede brindar una mejor calidad de vida para los AM, manteniéndolos activos, autovalentes y con menor riesgo de ECV.The population of senior citizens in the world is increasing quickly, and the situation in Chile also has also been following this trend. One of the great challenges that this presents for the country is the care and support for these citizens; for this reason, during the past two decades various programs for the elderly have been created.(1) Our research deals with these programs for senior citizens, where physical activity is the core activity and goal. It has been shown that physical activity helps diminish the risk of cardiovascular diseases, which are the main cause of death in Chile and around the world. (2) Researching the bibliographical sources of these programs, we have come to the conclusion that there are two major problems. On one hand, the description of the specific exercises and activities is basically inexistent, therefore the professional in charge is free to plan the activities as he/she sees fit. On the other hand, the number of programs that exist is very low, with a total of only 3 programs nationwide. Given the importance of physical activity for senior citizens, we believe that is it extremely important to further develop these programs, since they can help improve the quality of life for senior citizens, keeping them active, autonomous, and with lower risks of cardiovascular diseases

    Calibration of the Logarithmic-Periodic Dipole Antenna (LPDA) Radio Stations at the Pierre Auger Observatory using an Octocopter

    Get PDF
    An in-situ calibration of a logarithmic periodic dipole antenna with a frequency coverage of 30 MHz to 80 MHz is performed. Such antennas are part of a radio station system used for detection of cosmic ray induced air showers at the Engineering Radio Array of the Pierre Auger Observatory, the so-called Auger Engineering Radio Array (AERA). The directional and frequency characteristics of the broadband antenna are investigated using a remotely piloted aircraft (RPA) carrying a small transmitting antenna. The antenna sensitivity is described by the vector effective length relating the measured voltage with the electric-field components perpendicular to the incoming signal direction. The horizontal and meridional components are determined with an overall uncertainty of 7.4^{+0.9}_{-0.3} % and 10.3^{+2.8}_{-1.7} % respectively. The measurement is used to correct a simulated response of the frequency and directional response of the antenna. In addition, the influence of the ground conductivity and permittivity on the antenna response is simulated. Both have a negligible influence given the ground conditions measured at the detector site. The overall uncertainties of the vector effective length components result in an uncertainty of 8.8^{+2.1}_{-1.3} % in the square root of the energy fluence for incoming signal directions with zenith angles smaller than 60{\deg}.Comment: Published version. Updated online abstract only. Manuscript is unchanged with respect to v2. 39 pages, 15 figures, 2 table

    Multi-resolution anisotropy studies of ultrahigh-energy cosmic rays detected at the Pierre Auger Observatory

    Get PDF
    We report a multi-resolution search for anisotropies in the arrival directions of cosmic rays detected at the Pierre Auger Observatory with local zenith angles up to 8080^\circ and energies in excess of 4 EeV (4×10184 \times 10^{18} eV). This search is conducted by measuring the angular power spectrum and performing a needlet wavelet analysis in two independent energy ranges. Both analyses are complementary since the angular power spectrum achieves a better performance in identifying large-scale patterns while the needlet wavelet analysis, considering the parameters used in this work, presents a higher efficiency in detecting smaller-scale anisotropies, potentially providing directional information on any observed anisotropies. No deviation from isotropy is observed on any angular scale in the energy range between 4 and 8 EeV. Above 8 EeV, an indication for a dipole moment is captured; while no other deviation from isotropy is observed for moments beyond the dipole one. The corresponding pp-values obtained after accounting for searches blindly performed at several angular scales, are 1.3×1051.3 \times 10^{-5} in the case of the angular power spectrum, and 2.5×1032.5 \times 10^{-3} in the case of the needlet analysis. While these results are consistent with previous reports making use of the same data set, they provide extensions of the previous works through the thorough scans of the angular scales.Comment: Published version. Added journal reference and DOI. Added Report Numbe

    Ultrahigh-energy neutrino follow-up of Gravitational Wave events GW150914 and GW151226 with the Pierre Auger Observatory

    Get PDF
    On September 14, 2015 the Advanced LIGO detectors observed their first gravitational-wave (GW) transient GW150914. This was followed by a second GW event observed on December 26, 2015. Both events were inferred to have arisen from the merger of black holes in binary systems. Such a system may emit neutrinos if there are magnetic fields and disk debris remaining from the formation of the two black holes. With the surface detector array of the Pierre Auger Observatory we can search for neutrinos with energy above 100 PeV from point-like sources across the sky with equatorial declination from about -65 deg. to +60 deg., and in particular from a fraction of the 90% confidence-level (CL) inferred positions in the sky of GW150914 and GW151226. A targeted search for highly-inclined extensive air showers, produced either by interactions of downward-going neutrinos of all flavors in the atmosphere or by the decays of tau leptons originating from tau-neutrino interactions in the Earth's crust (Earth-skimming neutrinos), yielded no candidates in the Auger data collected within ±500\pm 500 s around or 1 day after the coordinated universal time (UTC) of GW150914 and GW151226, as well as in the same search periods relative to the UTC time of the GW candidate event LVT151012. From the non-observation we constrain the amount of energy radiated in ultrahigh-energy neutrinos from such remarkable events.Comment: Published version. Added journal reference and DOI. Added Report Numbe

    Genus Viburnum: Therapeutic Potentialities and Agro-Food- Pharma Applications

    Get PDF
    The genus Viburnum (Adoxaceae, Dipsacales) is of scientific interest due to the chemical components and diverse biological activities found across species of the genus, which includes more than 230 species of evergreen, semievergreen, or deciduous shrubs and small trees. Although frequently used as an ornament, the Viburnum species show biological properties with health-promoting effects. Fruits, flowers, and barks of certain species are used for pharmaceutical purposes or as cooking ingredients, hence containing biochemical compounds with health-promoting activity such are carotenoids, polyphenols, and flavonoids. However, its taxonomical determination is difficult, due to its wide distribution and frequent hybridizations; therefore, an objective classification would allow us to understand its biological activity based on its phytochemical components. More than sixty phytochemical compounds have been reported, where vibsanin-type diterpenes and their derivatives are the most prevalent. Leaves and twigs of V. dilatatum contain the largest number of phytochemicals among the genus. Through preclinical evidence, this study provides insight regarding antioxidant, antibacterial, anti-inflammatory, cytotoxic, and anticancer activities of genus Viburnum

    Design, upgrade and characterization of the silicon photomultiplier front-end for the AMIGA detector at the Pierre Auger Observatory

    Get PDF
    AMIGA (Auger Muons and Infill for the Ground Array) is an upgrade of the Pierre Auger Observatory to complement the study of ultra-high-energy cosmic rays (UHECR) by measuring the muon content of extensive air showers (EAS). It consists of an array of 61 water Cherenkov detectors on a denser spacing in combination with underground scintillation detectors used for muon density measurement. Each detector is composed of three scintillation modules, with 10 m2^2 detection area per module, buried at 2.3 m depth, resulting in a total detection area of 30 m2^2. Silicon photomultiplier sensors (SiPM) measure the amount of scintillation light generated by charged particles traversing the modules. In this paper, the design of the front-end electronics to process the signals of those SiPMs and test results from the laboratory and from the Pierre Auger Observatory are described. Compared to our previous prototype, the new electronics shows a higher performance, higher efficiency and lower power consumption, and it has a new acquisition system with increased dynamic range that allows measurements closer to the shower core. The new acquisition system is based on the measurement of the total charge signal that the muonic component of the cosmic ray shower generates in the detector.Comment: 40 pages, 33 figure

    A 3‐Year Sample of Almost 1,600 Elves Recorded Above South - America by the Pierre Auger Cosmic‐Ray Observatory

    Get PDF

    Measurement of the cosmic-ray energy spectrum above 2.5 x 10(18) eV using the Pierre Auger Observatory

    Get PDF
    We report a measurement of the energy spectrum of cosmic rays for energies above 2.5×1018^{18} eV based on 215,030 events recorded with zenith angles below 60°. A key feature of the work is that the estimates of the energies are independent of assumptions about the unknown hadronic physics or of the primary mass composition. The measurement is the most precise made hitherto with the accumulated exposure being so large that the measurements of the flux are dominated by systematic uncertainties except at energies above 5×1019^{19} eV. The principal conclusions are (1) The flattening of the spectrum near 5×1018^{18} eV, the so-called “ankle,” is confirmed. (2) The steepening of the spectrum at around 5×10Z19^{Z19} eV is confirmed. (3) A new feature has been identified in the spectrum: in the region above the ankle the spectral index γ of the particle flux (∝Eγ^{−γ }) changes from 2.51±0.03 (stat)±0.05 (syst) to 3.05±0.05 (stat)±0.10 (syst) before changing sharply to 5.1±0.3 (stat)±0.1 (syst) above 5×1019^{19} eV. (4) No evidence for any dependence of the spectrum on declination has been found other than a mild excess from the Southern Hemisphere that is consistent with the anisotropy observed above 8×1018^{18} eV
    corecore