504 research outputs found

    Structure of the medium formed in heavy ion collisions

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    We investigate the structure of the medium formed in heavy ion collisions using three different models: the Color String Percolation Model (CSPM), the Core-Shell-Color String Percolation Model (CSCSPM), and the Color Glass Condensate (CGC) framework. We analyze the radial distribution function of the transverse representation of color flux tubes in each model to determine the medium's structure. Our results indicate that the CSPM behaves as an ideal gas, while the CSCSPM exhibits a structural phase transition from a gas-like to a liquid-like structure. Additionally, our analysis of the CGC framework suggests that it produces systems that behave like interacting gases for AuAu central collisions at RHIC energies and liquid-like structures for PbPb central collisions at LHC energies.Comment: 15 pages, 8 figure

    VR4Axo: realidad virtual inmersiva para la identificación de representaciones axonométricas en dibujo técnico

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    El uso de juegos digitales simples motiva la participación y experimentación de los estudiantes favoreciendo su aprendizaje, especialmente en la educación primaria y secundaria. De la misma manera, la aplicación de entornos inmersivos e interactivos en la formación universitaria pueden también ser incluidos como una iniciativa pedagógica favorable aportando desde la creatividad y beneficiando el proceso de aprendizaje. En este trabajo se presenta una aplicación de Realidad Virtual (RV) 3D utilizando dispositivos con características inmersivas (lentes RV) que asistirá en la identificación de distintas representaciones axonométricas (isométrica, caballera y militar) en que se representa un objeto para ayudar al proceso de reconstrucción tridimensional. Se pretende que al realizar prácticas repetitivas de visualización y reconocimiento de las distintas perspectivas se desarrollen hábitos de observación en los detalles de los objetos a representar. Finalmente, esta aplicación se agrega al conjunto de herramientas creadas desde la materia con la finalidad de dar soporte para la resolución de los prácticos y favorecer el desarrollo de la inteligencia espacial de los estudiantes.Red de Universidades con Carreras en Informátic

    Self-Medication Practices, Use of Brand-Name, and Over-the-Counter Medicines by Peruvian Older Adults

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    Background Older adults are a particularly vulnerable group to drug use and self-medication. The aim of the study was to evaluate self-medication as a factor associated with the purchase of brand-name and over-the-counter (OTC) drugs in older adults in Peru. Methods A secondary analysis was performed using an analytical cross-sectional design of data from a nationally representative survey from 2014 to 2016. The exposure variable was self-medication, defined as the purchase of medicines without a prescription. The dependent variables were purchases of brand-name and OTC drugs, both as a dichotomous response (yes/no). Information of sociodemographic variables, health insurance, and the types of drugs purchased by the participants was collected. Crude prevalence ratios (PR) were calculated and adjusted using generalized linear models of the Poisson family, considering the complex sample of the survey. Results In this study, 1,115 respondents were evaluated, with a mean age of 63.8 years and a male proportion of 48.2%. The prevalence of self-medication was 66.6%, while the proportions of purchases of brand-name and OTC drugs were 62.4% and 23.6%, respectively. The adjusted Poisson regression analysis revealed an association between self-medication and the purchase of brand-name drugs (adjusted PR [aPR]=1.09; 95% confidence interval [CI]: 1.01–1.19). Likewise, self-medication was associated with the purchase of OTC medications (aPR=1.97; 95%CI: 1.55–2.51). Conclusions This study evidenced a high prevalence of self-medication in Peruvian older adults. Two-thirds of the surveyed people bought brand-name drugs, whereas one-quarter bought OTC drugs. Self-medication was associated with a greater likelihood of buying brand-name and OTC drugs

    Morphological identification and characterization of the formation of floral primordium in Vanilla planifolia (Orchidaceae)

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    ABSTRACT Objective: To study the formation of floral primordia and individual flower development in the inflorescence of vanilla (Vanilla planifolia Jacks Ex. Andrews). Design/methodology/approach: The study site was located at Rancho Xanathtlan, in Barriles, municipality of Gutiérrez Zamora, Veracruz. Inflorescence primordia and young inflorescences (racemes) at different stages of development were sampled from three different stem positions: basal (11-15 internodes), middle (6-10 internodes) and distal (1-5 internodes). Four samplings were made from February to May, and five replicates of each stem position were used per sampling date. Observations and characterization were carried out with a stereo microscope. Results: Seven developmental stages were described for the racemes of V. planifolia: (I) differentiated meristem of the floral inflorescence, (II) appearance of the third bract, (III) initiation of the formation of the racemes, (IV) elongation of the floral primordia, (V) development and growth of the individual floral primordia in the acropetal direction, (VI) anthesis of the inflorescence in the acropetal direction and (VII) complete flowering of the raceme. Five developmental stages of formation of individual flower primordia within the inflorescence were also identified, which occurred from the appearance of the third bract in the acropetal direction. Limitations on study/implications: Although this study denotes the first observations on the floral phenology of V. planifolia, there are still many questions about the biochemical processes and the interaction of environmental aspects in this floral development. Findings/conclusions: First aspects of floral formation within the inflorescence as well as floral phenology in Vanilla planifolia were shown. Keywords: Floral growth, floral phenology, inflorescences, orchids.Objective: To morphologically identify and characterize the formation of floral primordium and the individual flower development in Vanilla planifolia Jacks Ex. Andrews. Design/Methodology/Approach: Inflorescence primordia and young inflorescences in different development stages were sampled from the stem internodes of the following positions: basal (11-15), middle (6-10), and distal (1-5). Four samples were taken from each stem position from February to May, with five repetitions per sampling date. Observations and characterization were made with a stereo microscope. The study site was located at Rancho Xanathtlan, in Barriles, municipality of Gutiérrez Zamora, Veracruz. Results: The development of the V. planifolia raceme is described in seven phases: (I) differentiated meristem of the floral inflorescence; (II) appearance of the third bract; (III) initiation of the racemes formation; (IV) elongation of the floral primordium; (V) development and growth of the individual floral primordium in the acropetal direction, (VI) anthesis of the inflorescence in the acropetal direction; and (VII) complete flowering of the raceme. The development of the buds in the raceme is described in five stages from the appearance of the third bract in the acropetal direction. Study Limitations/Implications: The biochemical processes and the interaction of environmental aspects on the floral development of V. planifolia pose questions that remain unanswered. Findings/Conclusions: The first aspects of floral formation within the inflorescence of Vanilla planifolia were determined, along with its floral phenology

    Near Real-Time Automated Early Mapping of the Perimeter of Large Forest Fires from the Aggregation of VIIRS and MODIS Active Fires in Mexico

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    In contrast with current operational products of burned area, which are generally available one month after the fire, active fires are readily available, with potential application for early evaluation of approximate fire perimeters to support fire management decision making in near real time. While previous coarse-scale studies have focused on relating the number of active fires to a burned area, some local-scale studies have proposed the spatial aggregation of active fires to directly obtain early estimate perimeters from active fires. Nevertheless, further analysis of this latter technique, including the definition of aggregation distance and large-scale testing, is still required. There is a need for studies that evaluate the potential of active fire aggregation for rapid initial fire perimeter delineation, particularly taking advantage of the improved spatial resolution of the Visible Infrared Imaging Radiometer (VIIRS) 375 m, over large areas and long periods of study. The current study tested the use of convex hull algorithms for deriving coarse-scale perimeters from Moderate Resolution Imaging Spectroradiometer (MODIS) and Visible Infrared Imaging Radiometer Suite (VIIRS) active fire detections, compared against the mapped perimeter of the MODIS collection 6 (MCD64A1) burned area. We analyzed the effect of aggregation distance (750, 1000, 1125 and 1500 m) on the relationships of active fire perimeters with MCD64A1, for both individual fire perimeter prediction and total burned area estimation, for the period 2012–2108 in Mexico. The aggregation of active fire detections from MODIS and VIIRS demonstrated a potential to offer coarse-scale early estimates of the perimeters of large fires, which can be available to support fire monitoring and management in near real time. Total burned area predicted from aggregated active fires followed the same temporal behavior as the standard MCD64A1 burned area, with potential to also account for the role of smaller fires detected by the thermal anomalies. The proposed methodology, based on easily available algorithms of point aggregation, is susceptible to be utilized both for near real-time and historical fire perimeter evaluation elsewhere. Future studies might test active fires aggregation between regions or biomes with contrasting fuel characteristics and human activity patterns against medium resolution (e.g., Landsat and Sentinel) fire perimeters. Furthermore, coarse-scale active fire perimeters might be utilized to locate areas where such higher-resolution imagery can be downloaded to improve the evaluation of fire extent and impactFunding for this study was provided by CONAFOR/CONACYT Projects “CO2-2014-3-252620” and “CO-2018-2-A3-S-131553” for the development and enhancement of a Forest Fire Danger Prediction System for Mexico, funded by the Sectorial Fund for forest research, development and technological innovation “Fondo Sectorial para la investigación, el desarrollo y la innovación tecnológica forestal”S

    Survey of Wild Mammal Hosts of Cutaneous Leishmaniasis Parasites in Panama and Costa Rica

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    The eco-epidemiology of American cutaneous leishmaniasis (ACL) is driven by animal reservoir species that are a source of infection for sand flies that serve as vectors infecting humans with Leishmania spp parasites. The emergence and re-emergence of this disease across Latin America calls for further studies to identify reservoir species associated with enzootic transmission. Here, we present results from a survey of 52 individuals from 13 wild mammal species at endemic sites in Costa Rica and Panama where ACL mammal hosts have not been previously studied. For Leishmania spp. diagnostics we employed a novel PCR technique using blood samples collected on filter paper. We only found Leishmania spp parasites in one host, the two-toed sloth, Choloepus hoffmanni. Our findings add further support to the role of two-toed sloths as an important ACL reservoir in Central America

    Quid: observatorio de medios

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    El informe está dividido en cuatro apartados: “Derecho a la información y transparencia”, “La televisión mexicana”, “Empresas y prácticas periodísticas” y “Los que se fueron”. En el primero de ellos se presenta un texto que ayuda a entender cuál es el momento en el que se encuentran las propuestas legislativas para regular a los medios y las telecomunicaciones en México, y una evaluación de los primeros cinco años del Instituto de Transparencia e Información Pública de Jalisco. El segundo apartado del informe es ecléctico, pues se compone de artículos que trabajan distintas temáticas de la televisión:la estructura y oferta de la televisión en nuestro país (en particular en la ciudad de Guadalajara), la televisión por cable (enfatizando el caso de Megacable), un recuento de cómo se gestó el Canal 44 y de sus prospectivas en 2011, y los mundiales de futbol. La tercera parte del informe documenta algunas de las situaciones más importantes que se viven en el periodismo local: estos trabajos presentan sistemas en crisis (alta vulnerabilidad de los periodistas mexicanos ante un clima de violencia que lejos de disminuir va en aumento, y la participación, por acción u omisión, del Estado mexicano en la sistemática violación de los derechos de quienes dedican su vida al trabajo periodístico. Los siguientes artículos tratan sobre las transformaciones de las empresas periodísticas, particularmente las del sector de la prensa escrita: la rápida e inexorable desaparición de los suplementos culturales, y una radiografía sobre las formas de producción de algunas secciones internacionales de los periódicos tapatíos. Al final se presentan las semblanzas de José Galindo, Raúl Mora Lomelí, S.J., Tomás Eloy Martínez y Juan Pablo Rosell.ITESO, A.C

    ¿Es prioritario vacunar a niños de 3-11 años contra COVID-19 en Colombia?

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    En octubre 31 del 2021, Colombia inició la vacunación contra COVID-19 para niños de 3 a 11 años de edad, conla vacuna CoronaVac (Sinovac). Esta estrategia se implementó en ausencia de un informe técnico sobre la eficaciay seguridad de CoronaVac en niños, y sin una evaluación del costo-beneficio de esta, en comparación con otrasestrategias. En este comentario se consideran aspectos fundamentales que debieron tomarse en cuenta al ponderar silos beneficios de esta estrategia eran mayores que sus riesgos. Específicamente, la eficacia y seguridad de CoronaVacen niños de 3 a 11 años, la relación riesgo/beneficio de la estrategia, el rol de los niños en la transmisión comunitariade SARS-CoV-2, y las implicaciones éticas de la estrategia.En octubre 31 del 2021, Colombia inició la vacunación contra COVID-19 para niños de 3 a 11 años de edad, conla vacuna CoronaVac (Sinovac). Esta estrategia se implementó en ausencia de un informe técnico sobre la eficaciay seguridad de CoronaVac en niños, y sin una evaluación del costo-beneficio de esta, en comparación con otrasestrategias. En este comentario se consideran aspectos fundamentales que debieron tomarse en cuenta al ponderar silos beneficios de esta estrategia eran mayores que sus riesgos. Específicamente, la eficacia y seguridad de CoronaVacen niños de 3 a 11 años, la relación riesgo/beneficio de la estrategia, el rol de los niños en la transmisión comunitariade SARS-CoV-2, y las implicaciones éticas de la estrategia.En octubre 31 del 2021, Colombia inició la vacunación contra COVID-19 para niños de 3 a 11 años de edad, conla vacuna CoronaVac (Sinovac). Esta estrategia se implementó en ausencia de un informe técnico sobre la eficaciay seguridad de CoronaVac en niños, y sin una evaluación del costo-beneficio de esta, en comparación con otrasestrategias. En este comentario se consideran aspectos fundamentales que debieron tomarse en cuenta al ponderar silos beneficios de esta estrategia eran mayores que sus riesgos. Específicamente, la eficacia y seguridad de CoronaVacen niños de 3 a 11 años, la relación riesgo/beneficio de la estrategia, el rol de los niños en la transmisión comunitariade SARS-CoV-2, y las implicaciones éticas de la estrategia

    Intranasal administration of mesenchymal stem cell secretome reduces hippocampal oxidative stress, neuroinflammation and cell death, improving the behavioral outcome following perinatal asphyxia

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    Indexación: Scopus.PerinatalAsphyxia (PA) is a leading cause ofmotor and neuropsychiatric disability associated with sustained oxidative stress, neuroinflammation, and cell death, affecting brain development. Based on a rat model of global PA, we investigated the neuroprotective effect of intranasally administered secretome, derived from human adipose mesenchymal stem cells (MSC-S), preconditioned with either deferoxamine (an hypoxia-mimetic) or TNF-ff+IFN- (pro-inflammatory cytokines). PA was generated by immersing fetus-containing uterine horns in a water bath at 37 ffC for 21 min. Thereafter, 16 ffL of MSC-S (containing 6 ffg of protein derived from 2 ff 105 preconditioned-MSC), or vehicle, were intranasally administered 2 h after birth to asphyxia-exposed and control rats, evaluated at postnatal day (P) 7. Alternatively, pups received a dose of either preconditioned MSC-S or vehicle, both at 2 h and P7, and were evaluated at P14, P30, and P60. The preconditioned MSC-S treatment (i) reversed asphyxia-induced oxidative stress in the hippocampus (oxidized/reduced glutathione); (ii) increased antioxidative Nuclear Erythroid 2-Related Factor 2 (NRF2) translocation; (iii) increased NQO1 antioxidant protein; (iv) reduced neuroinflammation (decreasing nuclearNF-ffB/p65 levels and microglial reactivity); (v) decreased cleaved-caspase-3 cell-death; (vi) improved righting reflex, negative geotaxis, cliff aversion, locomotor activity, anxiety, motor coordination, and recognition memory. Overall, the study demonstrates that intranasal administration of preconditioned MSC-S is a novel therapeutic strategy that prevents the long-term effects of perinatal asphyxia. © 2020 by the authors.https://www.mdpi.com/1422-0067/21/20/780
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