878 research outputs found

    Use of mesh windbreaks for soil erosion in olive groves in southeastern Spain

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    We used windbreak nets to reduce erosion and sediment transport in a semiarid area. A 13x30thread·cm-2 and 39% mesh net facing the wind increased average erosion reduction up to 72% at a height of 0.4 m in recently tilled olive groves. The use of sonic anemometry techniques for identifying wind movement patterns has rarely been exploited for improving field studies, and much less for windbreaks. Sample components collected in traps placed at different heights and distances from the windbreak were analyzed. A Principal Components Analysis was carried out analyzing the combined effect of height and windbreak distance on variables associated with the first two components. Component C1 identified the height at which data were obtained, while Component C2 identified windbreak distance from the sampling point. The effectiveness of this system is shown by the reduction in weight of material caught in traps, and is a cheap and reusable tool applicable after tilling

    Análisis de los espectros de absorción de las películas radiocrómicas EBT2 y EBT3

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    Objetivo: Analizar los espectros de absorción neta de las películas radiocrómicas EBT2 y EBT3 para describir su influencia en el comportamiento de las curvas de dosis-respuesta. Metodología: Las películas se irradiaron en un acelerador lineal de 6 MV. La obtención de los espectros de absorción neta se realizó con espectrofotómetro UV/VIS. Las curvas de dosis-respuesta se obtuvieron con un escáner, un láser He-Ne y un espectrofotómetro. Resultados: El espectro de absorción de las EBT2 muestra tres bandas de absorción centradas que conservan la posición y aumentan su intensidad en función de la dosis, sin embargo, este comportamiento no se observa en las películas EBT3. La curva dosis-respuesta muestra la máxima sensibilidad utilizando el espectrofotómetro, pero no muestra un comportamiento definido. Implicaciones: Generación de nuevos conocimientos para la creación de nuevos sistemas ópticos capaces de amplificar la sensibilidad de la respuesta de las películas. Originalidad: Mostrar la correlación entre los espectros de absorción neta y su influencia en las curvas dosis-respuesta en tres diferentes sistemas ópticos. Conclusiones: El comportamiento de los espectros de absorción aunado al comportamiento de las curvas dosis-respuesta nos ayuda a descartar el uso de sistemas ópticos que no garanticen un uso clínico confiable

    Research advances in Risaralda. An overview of 8 experiences

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    I am honored to present to you this remarkable book, a testament to the invaluable research conducted in the fields of Health, Law, Engineering, and Administrative Sciences. Each chapter within these pages represents the culmination of extensive investigations carried out by dedicated scholars affiliated with the Red Universitaria de Risaralda (RUN), a network comprising 15 esteemed higher education institutions. Risaralda has emerged as a thriving hub for higher education, bolstered by its strategic geographical location, high quality of life, rich biodiversity, and competitive development. Today, Pereira ranks third in the index of university cities, with a student enrollment rate exceeding 63%. Close to 50,000 students pursue academic programs within the department. Notably, three institutions have achieved accreditation for their excellence in education, positioning Risaralda among the most competitive regions in terms of accredited academic programs. As we celebrate the 20th anniversary of the Red Universitaria de Risaralda in 2023, it is with great pride that we reflect on its pivotal role in fostering collaboration among public and private higher education institutions. Our mission has been twofold: attracting students to our region and supporting sustainable development and quality of life for our community. The mesa de investigación (research committee) has diligently coordinated the necessary actions to unite our researchers, facilitating an integrated approach to various disciplines and themes associated with the challenges faced in our region.CONTENT Introduction...................................................................................................................5 CHAPTER ONE. Tobacco Use and Social Skills in Children from Two Schools in Pereira, Colombia .......................................................................................................9 Angélica María Blanco Vanegas, Natalia Jeaneth Carmona Valencia and Ángela Liceth Pérez Rendón CHAPTER TWO. Lesbian visibility: between control and family silence.................................................35 Mireya Ospina Botero and Carolina Carmona Castilla CHAPTER THREE. New centralities in the city of Pereira, 1990-2019 .......................................................65 Cesar Augusto Castaño Galvis CHAPTER FOUR. Bibliometric analysis of scientific publications on the effect of roots on slope stability ...........................................................................................................95 Alejandro Alzate Buitrago, Raúl Alberto Gaviria Valencia, César Augusto Peñuela Meneses, Carlos Alberto Ospina Parra CHAPTER FIVE. Sustainability of local agri-food systems in a municipality of the Eje Cafetero, Colombia...............................................................................................131 Jaime Cardona Ocampo, Orlando Ospina Salazar and Julia Arredondo Botero CHAPTER SIX. Organizational strategies aimed at the Emberá Chamí unified indigenous reservation, Inamurcito community located in the municipality of Pueblo Rico, Risaralda............................................................................................................163 Carla Johana Martínez García and Yenny Marcela Vélez Herrera CHAPTER SEVEN. Psychomotor profile of children between 4 and 5 years old in the city of Pereira, Colombia ...................................................................................................199 Jhonatan Gonzalez-Santamaría and Claudia Jimena Lopez-Garcia CHAPTER EIGHT. Analysis of assembly tasks without the use of vision: an opportunity for the design of support technologies in manufacturing environments.....................217 Gustavo Adolfo Peña Marín, Carlos Andrés Quintero Diaztagle and Juan Diego Gallego Góme

    Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

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    The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

    Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

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    We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

    Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

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    A measurement of the cosmic-ray spectrum for energies exceeding 4×10184{\times}10^{18} eV is presented, which is based on the analysis of showers with zenith angles greater than 6060^{\circ} detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×10185.3{\times}10^{18} eV, the "ankle", the flux can be described by a power law EγE^{-\gamma} with index γ=2.70±0.02(stat)±0.1(sys)\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)} followed by a smooth suppression region. For the energy (EsE_\text{s}) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25(stat)1.2+1.0(sys))×1019E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19} eV.Comment: Replaced with published version. Added journal reference and DO

    A Prospective, Multicenter, Real-World Registry of Coronary Lithotripsy in Calcified Coronary Arteries

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    BACKGROUND Intravascular lithotripsy (IVL) has demonstrated effectiveness in the treatment of calcified lesions in selected patients with stable coronary disease. OBJECTIVES The authors sought to assess the performance of coronary IVL in calcified coronary lesions in a real-life, all comers, setting. METHODS The REPLICA-EPIC18 study prospectively enrolled consecutive patients treated with IVL in 26 centers in Spain. An independent core laboratory performed the angiographic analysis and event adjudication. The primary effectiveness endpoint assessed procedural success (successful IVL delivery, final diameter stenosis <20%, and absence of in- hospital major adverse cardiovascular events [MACE]). The primary safety endpoint measured freedom from MACE at 30 days. A predefined substudy compared outcomes between acute coronary syndrome (ACS) and chronic coronary syndrome (CCS) patients. RESULTS A total of 426 patients (456 lesions) were included, 63% of the patients presenting with ACS. IVL delivery was successful in 99% of cases. Before IVL, 49% of lesions were considered undilatable. The primary effectiveness endpoint was achieved in 66% of patients, with similar rates among CCS patients (68%) and ACS patients (65%). Likewise, there were no significant differences in angiographic success after IVL between CCS and ACS patients. The rate of MACE at 30 days (primary safety endpoint) was 3% (1% in CCS and 5% in ACS patients [P = 0.073]). CONCLUSIONS Coronary IVL proved to be a feasible and safe procedure in a real-life setting, effectively facilitating stent implantation in severely calcified lesions. Patients with ACS on admission showed similar angiographic success rates but showed a trend toward higher 30-day MACE compared with patients with CCS. (REPLICA-EPIC18 study [Registry of Coronary Lithotripsy in Spain]; NCT04298307) (c) 2024 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

    Crop pests and predators exhibit inconsistent responses to surrounding landscape composition

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    The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies
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