191 research outputs found

    El turismo urbano a través de la revalorización del patrimonio cultural

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    En los últimos años es notable el interés en los círculos académicos, por realizar estudios e investigaciones sobre el rol actual y potencial de las ciudades como espacio de destino turístico. La ciudad entendida como el resultado de una construcción social en un determinado territorio, donde pueden interpretarse el tiempo y la historia en su respuesta espacial, conforma un paisaje cargado de imágenes y símbolos representativos de la cultura de un colectivo social. En este sentido cabe citarse a Milton Santos cuando afirma que "el paisaje es una acumulación de tiempo". Las ciudades como destinos de los viajeros y posteriormente visitantes y turistas, tienen una historia tan amplia como la de la humanidad. El desarrollo de la agricultura y posteriormente el auge del comercio, fueron consolidando los primeros asentamientos que, transformándose en ciudades, se utilizaron como destino de los intercambios. En estos espacios, las autoridades políticas, económicas y religiosas, construyeron sus edificios emblemáticos probatorios del modelo temporal, con lo cual demostraban su autoridad y hegemonía ante sus ciudadanos y los de otras ciudades y territorios. Por estas razones, las ciudades se convirtieron en la representación del sistema de producción y económico imperante en las distintas etapas del desarrollo humano, tanto del capitalismo comercial, como del industrial y financiero actual. Por lo tanto siempre han intentado adaptar sus estructuras al sistema de producción dominante con sus especificidades temporales y sectoriales. Hoy las ciudades son un reflejo de las actividades de servicio.Evento también conocido bajo el nombre de "II Jornadas Platenses de Geografía"Facultad de Humanidades y Ciencias de la Educació

    Generation of an optimal target list for the Exoplanet Characterisation Observatory (EChO)

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    The Exoplanet Characterisation Observatory (EChO) has been studied as a space mission concept by the European Space Agency in the context of the M3 selection process. Through direct measurement of the atmospheric chemical composition of hundreds of exoplanets, EChO would address fundamental questions such as: What are exoplanets made of? How do planets form and evolve? What is the origin of exoplanet diversity? More specifically, EChO is a dedicated survey mission for transit and eclipse spectroscopy capable of observing a large, diverse and well-defined planetary sample within its four to six year mission lifetime. In this paper we use the end-to-end instrument simulator EChOSim to model the currently discovered targets, to gauge which targets are observable and assess the EChO performances obtainable for each observing tier and time. We show that EChO would be capable of observing over 170 relativity diverse planets if it were launched today, and the wealth of optimal targets for EChO expected to be discovered in the next 10 years by space and ground-based facilities is simply overwhelming. In addition, we build on previous molecular detectability studies to show what molecules and abundances will be detectable by EChO for a selection of real targets with various molecular compositions and abundances. EChO's unique contribution to exoplanetary science will be in identifying the main constituents of hundreds of exoplanets in various mass/temperature regimes, meaning that we will be looking no longer at individual cases but at populations. Such a universal view is critical if we truly want to understand the processes of planet formation and evolution in various environments. In this paper we present a selection of key results. The full results are available online (http://www.ucl.ac.uk/exoplanets/echotargetlist/).Comment: Accepted for publication in Experimental Astronomy, 20 pages, 10 figures, 3 table

    Incidence Rate for Hantavirus Infections without Pulmonary Syndrome, Panama

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    During 2001–2007, to determine incidence of all hantavirus infections, including those without pulmonary syndrome, in western Panama, we conducted 11 communitywide surveys. Among 1,129 persons, antibody prevalence was 16.5%–60.4%. Repeat surveys of 476 found that patients who seroconverted outnumbered patients with hantavirus pulmonary syndrome by 14 to 1

    Unprecedented tunability of riboswitch structure and regulatory function by sub-millimolar variations in physiological Mg2+

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    Riboswitches are cis-acting regulatory RNA biosensors that rival the efficiency of those found in proteins. At the heart of their regulatory function is the formation of a highly specific aptamer–ligand complex. Understanding how these RNAs recognize the ligand to regulate gene expression at physiological concentrations of Mg2+ ions and ligand is critical given their broad impact on bacterial gene expression and their potential as antibiotic targets. In this work, we used single-molecule FRET and biochemical techniques to demonstrate that Mg2+ ions act as fine-tuning elements of the amino acid-sensing lysC aptamer's ligand-free structure in the mesophile Bacillus subtilis. Mg2+ interactions with the aptamer produce encounter complexes with strikingly different sensitivities to the ligand in different, yet equally accessible, physiological ionic conditions. Our results demonstrate that the aptamer adapts its structure and folding landscape on a Mg2+-tunable scale to efficiently respond to changes in intracellular lysine of more than two orders of magnitude. The remarkable tunability of the lysC aptamer by sub-millimolar variations in the physiological concentration of Mg2+ ions suggests that some single-aptamer riboswitches have exploited the coupling of cellular levels of ligand and divalent metal ions to tightly control gene expression.Publisher PDFPeer reviewe

    The Ariel ground segment and instrument operations science data centre Organization, operation, calibration, products and pipeline

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    The ground segment for the ESA M4 Ariel exoplanet space mission is introduced. The ground segment encompasses the framework necessary to support the development of the Ariel mission to launch, in-flight operations and calibration, data processing pipeline and data handling, including user support. The structure of the ground segment and assumed responsibilities between ESA and the Ariel mission consortium is explained, along with their interfaces. The operational phases for the mission are introduced, including the early commissioning/verification phases, the science operations and the calibration strategy. The smooth transition of the ground segment through the various pre/post launch mission phases to nominal operations will be paramount in guaranteeing the success, scientific return and impact of the Ariel mission. The expected science data products are defined and a representative data processing pipeline is presented

    Real-time RT-PCR for Venezuelan equine encephalitis complex, Madariaga and Eastern equine encephalitis viruses: application in human and mosquito public health surveillance in Panama

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    Eastern equine encephalitis virus (EEEV), Madariaga virus (MADV), and Venezuelan equine encephalitis virus complex (VEEV) are New World alphaviruses transmitted by mosquitoes. They cause febrile and sometimes severe neurological disease in human and equine hosts. Detecting them during the acute phase is hindered by nonspecific symptoms and limited diagnostic tools. We designed and clinically assessed reverse transcription polymerase chain reaction assays (rRT-PCRs) for VEEV complex, MADV, and EEEV using whole-genome sequences. Validation involved 15 retrospective serum samples from 2015-2017 outbreaks, 150 mosquito pools from 2015, and 118 prospective samples from 2021-2022 surveillance in Panama. The rRT-PCRs detected VEEV complex RNA in 10 samples (66.7%) from outbreaks, with one having both VEEV complex and MADV RNAs. VEEV complex RNA was found in 5 suspected dengue cases from disease surveillance. The rRT-PCR assays identified VEEV complex RNA in 3 Culex (Melanoconion) vomerifer pools, leading to VEEV isolates in 2. Phylogenetic analysis revealed the VEEV ID subtype in positive samples. Notably, 11.9% of dengue-like disease patients showed VEEV infections. Together, our rRT-PCR validation in human and mosquito samples suggests this method can be incorporated into mosquito and human encephalitic alphavirus surveillance programs in endemic regions

    Convalescent Pulmonary Dysfunction Following Hantavirus Pulmonary Syndrome in Panama and the United States

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    The objective of this study was to document persistent pulmonary symptoms and pulmonary function abnormalities in adults surviving hantavirus pulmonary syndrome (HPS). Acute infection by most hantaviruses result in mortality rates of 25–35%, while in Panama the mortality rate of 10% is contrasted by an unusually high incidence. In all types of HPS, the viral prodrome, cardiopulmonary phase due to massive pulmonary capillary leak syndrome, and spontaneous diuresis are followed by a convalescent phase with exertional dyspnea for 3–4 weeks, but the frequency of persistent symptoms is not known. In this observational study of a convenience sample, 14 survivors of HPS caused by Choclo virus infection in Panama and 9 survivors of HPS caused by Sin Nombre virus infection in New Mexico completed a questionnaire and pulmonary function tests up to 8 years after infection. In both groups, exertional dyspnea persisted for 1–2 years after acute infection in 43% (Panama) and 77% (New Mexico) of survivors surveyed. Reduction in midexpiratory flows (FEF25–75%), increased residual volume (RV), and reduced diffusion capacity (DLCO/VA) also were common in both populations; but the severity of reduced expiratory flow did not correlate with exertional dyspnea. Symptoms referable to previous hantavirus infection had resolved within 3 years of acute infection in most but not all patients in the Panama group. Temporary exertional dyspnea and reduced expiratory flow are common in early convalescence after HPS but resolves in almost all patients

    Early impact of the COVID-19 pandemic on paediatric cancer care in Latin America

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    Although previous studies have suggested that the complications and mortality rate related to COVID-19 are substantially lower in the paediatric population,1 it is reasonable to consider that children with underlying conditions such as cancer will be at increased risk of severe disease...Fil: Vasquez, Liliana. Universidad de San Martín de Porres; Perú. Organización Panamericana de la Salud; PerúFil: Sampor, Claudia. Fundacion Hospital de Pediatria Professor Dr. Juan P. Garrahan; ArgentinaFil: Villanueva, Gabriela. Fundacion Hospital de Pediatria Professor Dr. Juan P. Garrahan; ArgentinaFil: Maradiegue, Essy. Instituto Nacional de Enfermedades Neoplasicas; PerúFil: Garcia Lombardi, Mercedes. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Gomez García, Wendy. Hospital Infantil Dr. Robert Reid Cabral; República DominicanaFil: Moreno, Florencia. Ministerio de Salud. Instituto Nacional del Cáncer; ArgentinaFil: Diaz, Rosdali. Instituto Nacional de Enfermedades Neoplasicas; PerúFil: Cappellano, Andrea M.. Universidade Federal de Sao Paulo; BrasilFil: Portilla, Carlos Andres. Universidad del Valle; ColombiaFil: Salas, Beatriz. Hospital del Niño Manuel Ascencio Villarroel; BoliviaFil: Nava, Evelinda. Hospital de Niños Jesus Garcia Coello; VenezuelaFil: Brizuela, Silvia. Instituto de Previsión Social ; ParaguayFil: Jimenez, Soledad. Hospital Solca Núcleo de Loja; EcuadorFil: Espinoza, Ximena. Hospital de Niños Dr. Roberto del Río; ChileFil: Gassant, Pascale Yola. Hôpital Saint-Damien; HaitíFil: Quintero, Karina. Children's Hospital Dr Jose Renan Esquivel; PanamáFil: Fuentes Alabi, Soad. Hospital Nacional de Niños Benjamin Bloom; El SalvadorFil: Velasquez, Thelma. No especifíca;Fil: Fu, Ligia. Hospital Escuela de Tegucigalpa; HondurasFil: Gamboa, Yessika. National Children's Hospital; Costa RicaFil: Quintana, Juan. Clinica Las Condes; ChileFil: Castiglioni, Mariela. Hospital Pereira Rossell; UruguayFil: Nuñez, Cesar. Children's Cancer Hospital; Estados UnidosFil: Moreno, Arturo. Hospital Universitario de Puebla; MéxicoFil: Luna Fineman, Sandra. State University of Colorado at Boulder; Estados UnidosFil: Luciani, Silvana. Pan American Health Organization; Estados UnidosFil: Chantada, Guillermo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; Argentina. Hospital Sant Joan de Deu Barcelona; Españ

    Can scenario-planning support community-based natural resource management? Experiences from three countries in latin america

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    Community Based Natural Resource Management (CBNRM) is a concept critical to managing socio-ecological systems, but whose implementation needs strengthening. Scenario-planning is one approach that may offer benefits relevant to CBNRM, but whose potential is not yet well understood. We therefore designed, trialled and evaluated a scenario-planning method intended to support CBNRM at three cases, located in Colombia, Mexico and Argentina. Implementing scenario-planning was judged as worthwhile in all three cases, although aspects of it could be challenging to facilitate. The benefits generated were relevant to strengthening CBNRM: encouraging the participation of local people and using their knowledge; enhanced consideration and adaption of future change; and supporting the development of systems thinking. Tracing exactly when and how these benefits arise is challenging, but two elements of the method seemed particularly useful. Firstly, using a systematic approach to discuss how drivers of change may affect local socio-ecological systems helped to foster systems thinking and identify connections between issues. Secondly, explicitly focusing on how to use and respond to scenarios helped identify specific practical activities ('response options') that would support CBNRM despite the pressures of future change. Discussions about response options also highlighted the need for support by other actors (e.g. policy groups): this raises the question of when and how other actors and other sources of knowledge should be involved in scenario-planning, so as to encourage their buy-in to actions identified by the process. We suggest other CBNRM initiatives may benefit from adapting and applying scenario-planning. However, these initiatives should be carefully monitored since further research is required to understand how and when scenario-planning methods may produce benefits, and their strengths and weaknesses versus other methods

    A chemical survey of exoplanets with ARIEL

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    Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio
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