286 research outputs found

    Desarrollo e implementación del curso de introducción a la física en la universidad autónoma de la ciudad de México (UACM)

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    El trabajo que ahora presentamos da cuenta del proceso de implementación del curso de Introducción a la Física que se imparte en la UACM basado en el trabajo del Physics Education Group de la Universidad de Washington. Éste se desarrolla desde un enfoque constructivista, con la intención de desarrollar conocimiento operativo y habilidades de pensamiento científico como elementos que pensamos pueden contrarrestar el fracaso usual en los cursos de física. Los resultados que se presentan en esta ponencia buscan dar evidencia de que la efectividad en el aprendizaje de la ciencia requiere del involucramiento mental activo y de la consideración del estado inicial real del estudiante, entre otras cosas; asimismo, se presenta un marco metodológico para implementar y evaluar actividades de aprendizaje bajo las mismas premisas

    Primera encuesta de "Nuestro cinema"

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    Gómez Mesa, L.; Gil, R.; Villegas López, M.; Ysern, A.; De Ubieta, JG.; Antonino, A. (1932). Primera encuesta de "Nuestro cinema". Nuestro cinema. (3):65-71. http://hdl.handle.net/10251/42786.Importación Masiva6571

    Influence of age on the occurrence of adverse events in rheumatic patients at the onset of biological treatment : Data from the BIOBADASER III register

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    To assess whether age, at the beginning of biologic treatment, is associated with the time a first adverse event (AE) appears in patients with rheumatoid arthritis (RA), ankylosing spondylitis (AS), or psoriatic arthritis (PsA). All patients in the BIOBADASER registry diagnosed with RA, AS, and PsA, and classified as young ( 75 years old) at start of biological treatment were included. Factors associated with the appearance of a first AE using adjusted incidence rate ratios (IRR) (Poisson regression) were analyzed. Survival to first AE was studied by Kaplan-Meier analysis and hazard ratios (HR) by Cox regression. 2483 patients were included: 1126 RA, 680 PsA, and 677 AS. Age group stratification was as follows: 63 young, 2127 adults, 237 elderly, and 56 very elderly. Regression model revealed an increased probability of suffering a first AE at age 65 years or older [IRR elderly: 1.42 (CI95% 1.13-1.77)]. Other characteristics associated with AE were female gender, the use of DMARDs, including methotrexate, the presence of comorbidities, and the time of disease duration. Factors that had the greatest impact on survival over a first AE were age > 75 years [HR 1.50 (1.01-2.24)] and female gender [HR 1.42 (1.22-1.64)]. Age at the start of treatment and female gender are key factors associated with the appearance of a first AE with biologics. Other factors related to patient status and treatment were also associated with a first AE in rheumatic patients treated with biologics

    Cigarette smoke induces pulmonary arterial dysfunction through an imbalance in the redox status of the soluble guanylyl cyclase

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    Chronic obstructive pulmonary disease (COPD), whose main risk factor is cigarette smoking (CS), is one of the most common diseases globally. Some COPD patients also develop pulmonary hypertension (PH), a severe complication that leads to premature death. Evidence suggests reactive oxygen species (ROS) involvement in COPD and PH, especially regarding pulmonary artery smooth muscle cells (PASMC) dysfunction. However, the effects of CS-driven oxidative stress on the pulmonary vasculature are not completely understood. Herein we provide evidence on the effects of CS extract (CSE) exposure on PASMC regarding ROS production, antioxidant response and its consequences on vascular tone dysregulation. Our results indicate that CSE exposure promotes mitochondrial fission, mitochondrial membrane depolarization and increased mitochondrial superoxide levels. However, this superoxide increase did not parallel a counterbalancing antioxidant response in human pulmonary artery (PA) cells. Interestingly, the mitochondrial superoxide scavenger mitoTEMPO reduced mitochondrial fission and membrane potential depolarization caused by CSE. As we have previously shown, CSE reduces PA vasoconstriction and vasodilation. In this respect, mitoTEMPO prevented the impaired nitric oxide-mediated vasodilation, while vasoconstriction remained reduced. Finally, we observed a CSE-driven downregulation of the Cyb5R3 enzyme, which prevents soluble guanylyl cyclase oxidation in PASMC. This might explain the CSE-mediated decrease in PA vasodilation. These results provide evidence that there might be a connection between mitochondrial ROS and altered vasodilation responses in PH secondary to COPD, and strongly support the potential of antioxidant strategies specifically targeting mitochondria as a new therapy for these diseasesThe Spanish Ministerio de Ciencia e Innovacion, ´ Programa Retos en Investigacion ´ (grant number PID2019-104406RB-100) to MJC provided the financial support for the conduct of the research included in this manuscript. Garantia Juvenil program from Comunidad de Madrid contributed with the research assistant contract to M-R,

    The ecology of peace : preparing Colombia for new political and planetary climates

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    ABSTRACT: Colombia, one of the world’s most species-rich nations, is currently undergoing a profound social transition: the end of a decadeslong conflict with the Revolutionary Armed Forces of Colombia, known as FARC. The peace agreement process will likely transform the country’s physical and socioeconomic landscapes at a time when humans are altering Earth’s atmosphere and climate in unprecedented ways. We discuss ways in which these transformative events will act in combination to shape the ecological and environmental future of Colombia. We also highlight the risks of creating perverse development incentives in these critical times, along with the potential benefits – for the country and the world – if Colombia can navigate through the peace process in a way that protects its own environment and ecosystems

    Nanoencapsulated Clove Oil Applied as an Anesthetic at Slaughtering Decreases Stress, Extends the Freshness, and Lengthens Shelf Life of Cultured Fish

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    In the aquaculture industry, fish are stunned using a wide range of methods, but all of them trigger stress responses and affect the fish flesh quality. Chilled water is considered one of the most efficient methods, but even this is not a stress‐free experience for the fish. Anesthetics included in the ice slurry or in water could decrease this stress and delay the loss of flesh quality. In this work, we analyze the effect of clove oil (CO) nanoencapsulated in β‐cyclodextrins (β‐CD) (CO + β‐CD), incorporated in the stunning bath, on the stress response and the organoleptic attributes of fresh marine and freshwater fish from four economically important fish species: Atlantic salmon, European seabass, Nile tilapia, and Rainbow trout. CO + β‐CD reduces the time required to induce anesthesia, independently of water salinity, habitat or water temperature. The plasmatic glucose and cortisol levels decreased in all four species, although the concentrations of CO varied between species. Moreover, plasmatic lactate level differed between the marine and freshwater fish. The use of CO + β‐CD extended the shelf life of fish from all the species studied (by 3–7 days). In conclusion, using CO encapsulated in β‐CD for anesthetizing fish can be regarded as an improved fish‐stunning technique that reduces the anesthesia‐induction time, decreases the stress response, and extends the shelf life of fresh fish.Versión del edito

    The Neurovascular Unit Dysfunction in Alzheimer's Disease

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    Funding: This work was supported by Fondo Nacional de Ciencia y Tecnologia (FONDOCyT) from the Ministry of Higher Education, Science and Technology, Dominican Republic (2015-3A2-127 to M.P.-H.) and (2018-2019-2A3-208 to J.L.-M. and M.P.-H.). Acknowledgments: The authors want to express their gratitude to the Mexican families who have donated the brain of their loved ones affected by Alzheimer’s disease and made our research possible. We also want to express our gratitude to the Union Medical University Clinic, Dominican Republic, for their support and collaboration in developing of this research project. This work is dedicated to the memory of José Raúl Mena López †.Peer reviewedPublisher PD

    Comparative In Vitro Activity of Ceftolozane/Tazobactam against Clinical Isolates of Pseudomonas aeruginosa and Enterobacterales from Five Latin American Countries

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    Background: Ceftolozane/tazobactam (C/T) is a combination of an antipseudomonal oxyiminoaminothiazolyl cephalosporin with potent in vitro activity against Pseudomonas aeruginosa and tazobactam, a known β-lactamase inhibitor. The aim of this study was to evaluate the activity of C/T against clinical isolates of P. aeruginosa and Enterobacterales collected from five Latin American countries between 2016 and 2017, before its clinical use in Latin America, and to compare it with the activity of other available broad-spectrum antimicrobial agents. Methods: a total of 2760 clinical isolates (508 P. aeruginosa and 2252 Enterobacterales) were consecutively collected from 20 hospitals and susceptibility to C/T and comparator agents was tested and interpreted following the current guidelines. Results: according to the CLSI breakpoints, 68.1% (346/508) of P. aeruginosa and 83.9% (1889/2252) of Enterobacterales isolates were susceptible to C/T. Overall, C/T demonstrated higher in vitro activity than currently available cephalosporins, piperacillin/tazobactam and carbapenems when tested against P. aeruginosa, and its performance in vitro was comparable to fosfomycin. When tested against Enterobacterales, it showed higher activity than cephalosporins and piperacillin/tazobactam, and similar activity to ertapenem. Conclusions: these results show that C/T is an active β-lactam agent against clinical isolates of P. aeruginosa and Enterobacterales.Fil: García Betancur, Juan Carlos. Universidad El Bosque;Fil: De La Cadena, Elsa. Universidad El Bosque;Fil: Mojica, María F.. Universidad El Bosque; . Case Western Reserve University; Estados UnidosFil: Hernández Gómez, Cristhian. Universidad El Bosque;Fil: Correa, Adriana. Universidad Santiago de Cali; ColombiaFil: Radice, Marcela Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y BioquÍmica. Instituto de Investigaciones En Bacteriología y Virología Molecular (IBaViM); ArgentinaFil: Castañeda Méndez, Paulo. Fundacion Clinica Medica Sur; MéxicoFil: Jaime Villalon, Diego A.. Fundacion Clinica Medica Sur; MéxicoFil: Gales, Ana C.. Universidade Federal de Sao Paulo; BrasilFil: Munita, José M.. Universidad del Desarrollo; ChileFil: Villegas, María Virginia. Universidad El Bosque

    Herschel FIR counterparts of selected Ly-alpha emitters at z~2.2. Fast evolution since z~3 or missed obscured AGNs?

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    Ly-alpha emitters (LAEs) are seen everywhere in the redshift domain from local to z~7. Far-infrared (FIR) counterparts of LAEs at different epochs could provide direct clues on dust content, extinction, and spectral energy distribution (SED) for these galaxies. We search for FIR counterparts of LAEs that are optically detected in the GOODS-North field at redshift z~2.2 using data from the Herschel Space Telescope with the Photodetector Array Camera and Spectrometer (PACS). The LAE candidates were isolated via color-magnitude diagram using the medium-band photometry from the ALHAMBRA Survey, ancillary data on GOODS-North, and stellar population models. According to the fitting of these spectral synthesis models and FIR/optical diagnostics, most of them seem to be obscured galaxies whose spectra are AGN-dominated. From the analysis of the optical data, we have observed a fraction of AGN or composite over source total number of ~0.75 in the LAE population at z~2.2, which is marginally consistent with the fraction previously observed at z=2.25 and even at low redshift (0.2<z<0.45), but significantly different from the one observed at redshift ~3, which could be compatible either with a scenario of rapid change in the AGN fraction between the epochs involved or with a non detection of obscured AGN in other z=2-3 LAE samples due to lack of deep FIR observations. We found three robust FIR (PACS) counterparts at z~2.2 in GOODS-North. This demonstrates the possibility of finding dust emission in LAEs even at higher redshifts.Comment: 11 pages (including Appendices), 6 figures. Accepted for publication in Astronomy & Astrophysics Letters (two references added
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