4,775 research outputs found

    Efectividad de la estrategia metodológica “Lloviendo Memes” para fomentar la comprensión lectora de textos literarios, en Undécimo grado A, Instituto Nacional Héroes y Mártires, Pueblo Nuevo, I Semestre de 2019.

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    Este artículo resume los resultados del estudio efectividad de la estrategia metodológica “Lloviendo Memes” para fomentar la comprensión lectora de textos literarios, investigación realizada en el Instituto Nacional Héroes y Mártires, Pueblo Nuevo en el I Semestre de 2019. El objetivo de este estudio fue determinar la efectividad de esta estrategia para fomentar la comprensión lectora de textos literarios en undécimo A. El resultado fue la aplicación de una metodológica efectiva que por su naturaleza interactiva, heurística, sinérgica, y por ende holística permitió incentivar la motivación en los estudiantes. Por lo antes descrito, el aporte teórico de este estudio es la revisión bibliográfica sobre estrategias metodológicas de comprensión lectora, por otro parte, la contribución práctica es la estructuración de una propuesta metodológica mediada por las Tecnologías de Información y la Comunicación (TIC) que tiene como elemento principal la inserción del meme educativo en la didáctica de la Lengua Literatura específicamente en los textos literarios. Por consiguiente se enmarca en la línea de las investigaciones dirigidas a alcanzar calidad educativa y transformar el acto didáctico en un escenario donde los docentes y estudiantes logren apropiarse de recursos tecnológicos para construir su acervo epistemológico

    Efectividad de la Estrategia metodológica “Lloviendo memes” para fomentar la comprensión lectora de textos literarios

    Get PDF
    Este artículo resume los resultados del estudio efectividad de la estrategia metodológica “Lloviendo Memes” para fomentar la comprensión lectora de textos literarios, investigación realizada en el Instituto Nacional Héroes y Mártires, Pueblo Nuevo en el I Semestre de 2019. El objetivo de este estudio fue determinar la efectividad de esta estrategia para fomentar la comprensión lectora de textos literarios en undécimo A. El resultado fue la aplicación de una metodológica efectiva que por su naturaleza interactiva, heurística, sinérgica, y por ende holística permitió incentivar la motivación en los estudiantes. Por lo antes descrito, el aporte teórico de este estudio es la revisión bibliográfica sobre estrategias metodológicas de comprensión lectora, por otro parte, la contribución práctica es la estructuración de una propuesta metodológica mediada por las Tecnologías de Información y la Comunicación (TIC) que tiene como elemento principal la inserción del meme educativo en la didáctica de la Lengua Literatura específicamente en los textos literarios. Por consiguiente, se enmarca en la línea de las investigaciones dirigidas a alcanzar calidad educativa y transformar el acto didáctico en un escenario donde los docentes y estudiantes logren apropiarse de recursos tecnológicos para construir su acervo epistemológico

    Study of secondary muons detected within the tunnels of the Cholula pyramid

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    The pyramid of Cholula was built at the beginning of 100 B.C. and during of period of 500 years it was finished, had several new constructions, based on the previous constructions. The primarily material of construction is the adobe. Early in 1931 archaeological excavations began with the intention of exploring the interior of the pyramid, excavations were stopped in 1971, and to date no further excavations have been carried out. This work shows the first measurements of muons, particles that are very penetrating, these are generated by primary cosmic rays that was incoming in the atmosphere and these generates a rain of secondary particles, among them the muons. To measure this kind of particles was implemented a detector system, it is formed by a scintillator plastic coupled to a tube photomultiplier; the signals were acquired by mean of an oscilloscope. The detector was collocated near of the center of the pyramid; the location belongs to the maxima concentration in mass over the detector. Graphs of the charge distribution, maximum amplitude and characteristic rise times of the generated pulses in a plastic scintillator are shown, this is scintillator was synthesized in the materials laboratory of the FCFM-BUAP. In addition the optical characterization of the same was realized

    Discordance Between SARS-CoV-2-specific Cell-mediated and Antibody Responses Elicited by mRNA-1273 Vaccine in Kidney and Liver Transplant Recipients

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    Background: Severe acute respiratory syndrome coronavirus 2-specific cell-mediated immunity (SARS-CoV-2-CMI) elicited by mRNA-based vaccines in solid organ transplant (SOT) recipients and its correlation with antibody responses remain poorly characterized. Methods: We included 44 (28 kidney, 14 liver, and 2 double organ) recipients who received the full series of the mRNA-1273 vaccine. SARS-CoV-2-CMI was evaluated at baseline, before the second dose, and at 2 wk after completion of vaccination by an ELISpot-based interferon-γ FluoroSpot assay using overlapping peptides covering the S1 domain. SARS-CoV-2 immunoglobulin G seroconversion and serum neutralizing activity against the spike protein were assessed at the same points by commercial ELISA and an angiotensin-converting enzyme-2/spike antibody inhibition method, respectively. Postvaccination SARS-CoV-2-CMI was compared with 28 healthcare workers who received the BNT162b2 vaccine. Results: Positive SARS-CoV-2-CMI increased from 6.8% at baseline to 23.3% after the first mRNA-1273 dose and 59.5% after the completion of vaccination (P < 0.0001). Lower rates were observed for immunoglobulin G seroconversion (2.3%, 18.6%, and 57.1%, respectively) and neutralizing activity (2.3%, 11.6%, and 31.0%). There was a modest correlation between neutralizing titers and the magnitude of SARS-CoV-2-CMI (Spearman's rho: 0.375; P = 0.015). Fifteen recipients (35.7%) mounted SARS-CoV-2-CMI without detectable neutralizing activity, whereas 3 (7.1%) did the opposite, yielding poor categorical agreement (Kappa statistic: 0.201). Rates of positive SARS-CoV-2-CMI among SOT recipients were significantly decreased compared with nontransplant controls (82.1% and 100.0% after the first dose and completion of vaccination, respectively; P < 0.0001). Kidney transplantation, the use of tacrolimus and prednisone, and the number of immunosuppressive agents were associated with lower cell-mediated responses. Results remained unchanged when 3 recipients with prevaccination SARS-CoV-2-CMI were excluded. Conclusions: Two-thirds of SOT recipients mounted SARS-CoV-2-CMI following vaccination with mRNA-1273. Notable discordance was observed between vaccine-induced cell-mediated and neutralizing humoral immunities. Future studies should determine whether these patients with incomplete responses are effectively protected.This work was supported by the Instituto de Salud Carlos III, Spanish Ministry of Science and Innovation (COVID-19 Research Call COV20/00181) and cofinanced by the European Development Regional Fund “A way to achieve Europe.” M.F.R. holds a research contract “Miguel Servet” (CP18/00073) and R.L.G. a research contract “Rio Hortega” (CM19/00120), both from the Instituto de Salud Carlos III, Spanish Ministry of Science and InnovationS

    An in vitro co-culture model of esophageal cells identifies ascorbic acid as a modulator of cell competition

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    <p>Abstract</p> <p>Background</p> <p>The evolutionary dynamics between interacting heterogeneous cell types are fundamental properties of neoplastic progression but can be difficult to measure and quantify. Cancers are heterogeneous mixtures of mutant clones but the direct effect of interactions between these clones is rarely documented. The implicit goal of most preventive interventions is to bias competition in favor of normal cells over neoplastic cells. However, this is rarely explicitly tested. Here we have developed a cell culture competition model to allow for direct observation of the effect of chemopreventive or therapeutic agents on two interacting cell types. We have examined competition between normal and Barrett's esophagus cell lines, in the hopes of identifying a system that could screen for potential chemopreventive agents.</p> <p>Methods</p> <p>One fluorescently-labeled normal squamous esophageal cell line (EPC2-hTERT) was grown in competition with one of four Barrett's esophagus cell lines (CP-A, CP-B, CP-C, CP-D) under varying conditions and the outcome of competition measured over 14 days by flow cytometry.</p> <p>Results</p> <p>We demonstrate that ascorbic acid (vitamin C) can help squamous cells outcompete Barrett's cells in this system. We are also able to show that ascorbic acid's boost to the relative fitness of squamous cells was increased in most cases by mimicking the pH conditions of gastrointestinal reflux in the lower esophagus.</p> <p>Conclusions</p> <p>This model is able to integrate differential fitness effects on various cell types, allowing us to simultaneously capture effects on interacting cell types without having to perform separate experiments. This model system may be used to screen for new classes of cancer prevention agents designed to modulate the competition between normal and neoplastic cells.</p

    Improving stem quality assessment based on national forest inventory data: an approach applied to Spanish forests

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    20 Pág.Key message: This paper proposes a methodology that could be considered as a base for a harmonized protocol for stem-quality reporting in Europe while conducting National Forest Inventories, in order to cost-efficiently obtain a visual wood quality proxy. The importance of the variables selected, the limitations identified, and some improvements to the methodology are suggested. Forest areas with better wood quality, which in turn it would be useful for breeding programs, can be easily detected. Context: The establishment of harmonized standards or indicators that allow us to determine the quality of the wood present in a forest prior to its exploitation has long been demanded by the European forestry sector, although agreed methodologies for the evaluation of wood quality in standing trees, which is one of the sector’s most urgent requirements, have not, as yet, been implemented. Aims: To develop a protocol that visually characterizes wood quality on standing trees in a cost-effective way for the National Forest Inventory (NFI). After some improvements, it can be considered as a base for a European harmonized protocol. Methods: In this article, we analyze the implementation, in the NFI, of a visual wood-quality assessment methodology in forests of Central Spain based on the different European standards as well as on research papers addressing this issue. Results: The silvicultural practices employed are of the utmost importance to obtain the best wood quality, regardless of the species. Several areas with higher wood quality were identified as well as areas most affected by specific pests in the studied region. The impact of the variables measured (e.g., branchiness, crookedness, maximum branch diameter) is discussed. Conclusion: It is feasible to estimate a proxy for wood quality on standing trees in the NFI. Furthermore, after studying the inventory data provided, several enhancements are proposed, not only to improve wood-quality estimates but also to optimize fieldwork costs. Harmonizing NFIs to assess and map European standing wood quality can be achieved.This work was supported by the Spanish Ministry of Agriculture, Fishing and Food (Encomienda de Gestión. EG17-042 “Soporte científico a la generación de información Forestal”).Peer reviewe

    Association between tissue hypoxia and elevated non-protein sulphydryl concentrations in human cervical carcinoma xenografts

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    A double staining technique was developed for the simultaneous measurement of tissue hypoxia and the concentration of non-protein sulphydryls (NPSH), based on the fluorinated nitroimidazole EF5 and the fluorescent histochemical NPSH stain 1-(4-chloromercuriphenoylazo)-naphthol-2 (mercury orange). Cryostat sections of tumour tissue were examined by fluorescence image analysis, using a computer-controlled microscope stage to generate large tiled field images of the cut tumour surface. This method was applied to the human cervical squamous cell carcinoma lines ME180 and SiHa, grown as xenografts in severe combined immunodeficient (SCID) mice, in order to determine if there is a systematic relationship between tissue hypoxia and NPSH levels. Hypoxic regions of the tumours, defined by EF5 labelling, were found to show greater NPSH concentrations relative to better oxygenated regions. This is probably due to increases in glutathione, since the ME180 and SiHa xenografts contained low levels of cysteine and metallothionein; the other major cellular thiols that can bind to mercury orange. Because the effects of glutathione on radiation and chemotherapy resistance are likely to be greater under hypoxic conditions, these results have potentially important implications for the study of resistance mechanisms in solid tumours. © 1999 Cancer Research Campaig

    Population genetics of cancer cell clones: possible implications of cancer stem cells

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    Abstract Background The population dynamics of the various clones of cancer cells existing within a tumour is complex and still poorly understood. Cancer cell clones can be conceptualized as sympatric asexual species, and as such, the application of theoretical population genetics as it pertains to asexual species may provide additional insights. Results The number of generations of tumour cells within a cancer has been estimated at a minimum of 40, but high cancer cell mortality rates suggest that the number of cell generations may actually be in the hundreds. Such a large number of generations would easily allow natural selection to drive clonal evolution assuming that selective advantages of individual clones are within the range reported for free-living animal species. Tumour cell clonal evolution could also be driven by variation in the intrinsic rates of increase of different clones or by genetic drift. In every scenario examined, the presence of cancer stem cells would require lower selection pressure or less variation in intrinsic rates of increase. Conclusions The presence of cancer stem cells may result in more rapid clonal evolution. Specific predictions from theoretical population genetics may lead to a greater understanding of this process.</p
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