251 research outputs found
Characterization of High-Risk HPV/EBV Co-Presence in Pre-Malignant Cervical Lesions and Squamous Cell Carcinomas
High-risk human papillomaviruses (HR-HPVs) are the etiological agents of cervical cancer. However, a low proportion of HR-HPV-infected women finally develop this cancer, which suggests the involvement of additional cofactors. Epstein–Barr virus (EBV) has been detected in cervical squamous cell carcinomas (SCCs) as well as in low-(LSIL) and high-grade (HSIL) squamous in-traepithelial lesions, although its role is unknown. In this study, we characterized HR-HPV/EBV co-presence and viral gene expression in LSIL (n = 22), HSIL (n = 52), and SCC (n = 19) from Chilean women. Additionally, phenotypic changes were evaluated in cervical cancer cells ectopically expressing BamHI-A Rightward Frame 1 (BARF1). BARF1 is a lytic gene also expressed in EBV-positive epithelial tumors during the EBV latency program. HPV was detected in 6/22 (27.3%) LSIL, 38/52 (73.1%) HSIL, and 15/19 (78.9%) SCC cases (p < 0.001). On the other hand, EBV was detected in 16/22 (72.7%) LSIL, 27/52 (51.9%) HSIL, and 13/19 (68.4%) SCC cases (p = 0.177). HR-HPV/EBV co-presence was detected in 3/22 (13.6%) LSIL, 17/52 (32.7%) HSIL, and 11/19 (57.9%) SCC cases (p = 0.020). Additionally, BARF1 transcripts were detected in 37/55 (67.3%) of EBV positive cases and in 19/30 (63.3%) of HR-HPV/EBV positive cases. Increased proliferation, migration, and epithelial-mesenchymal transition (EMT) was observed in cervical cancer cells expressing BARF1. Thus, both EBV and BARF1 transcripts are detected in low-and high-grade cervical lesions as well as in cervical carcinomas. In addition, BARF1 can modulate the tumor behavior in cervical cancer cells, suggesting a role in increasing tumor aggressiveness.Fil: Blanco, Rancés. Universidad de Chile. Facultad de Medicina. Institutos de Ciencias Biomedicas.; ChileFil: Carrillo-Beltrán, Diego. Universidad de Tarapaca. Instituto de Alta Investigacion.; ChileFil: Muñoz, Juan P.. Universidad de Tarapaca. Instituto de Alta Investigacion.; ChileFil: Osorio, Julio C.. Universidad de Chile; ChileFil: Tapia, Julio C.. Universidad de Chile. Facultad de Medicina. Institutos de Ciencias Biomedicas.; ChileFil: Burzio, Verónica A.. Universidad Andrés Bello; ChileFil: Gallegos, Iván. Universidad de Santiago de Chile. Hospital Clinico San Borja Arriaran; ChileFil: Calaf, Gloria M.. Universidad de Tarapaca. Instituto de Alta Investigacion.; ChileFil: Chabay, Paola Andrea. Gobierno de la Ciudad de Buenos Aires. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas; ArgentinaFil: Aguayo, Francisco. Universidad de Chile. Facultad de Medicina. Institutos de Ciencias Biomedicas.; Chil
Tails and streams around the Galactic globular clusters NGC 1851, NGC 1904, NGC 2298 and NGC 2808
We present Dark Energy Camera imaging for the peculiar Galactic globular clusters NGC 1851, NGC 1904 (M 79), NGC 2298 and NGC 2808. Our deep photometry reveals that all the clusters have an important contribution of stars beyond their King tidal radii and present tails with different morphologies. We have also explored the surroundings of the clusters where the presence of the Canis Major overdensity and/or the low Galactic latitude Monoceros ring at d⊙ ∼ 8 kpc is evident. A second stellar system is found at d⊙ ∼ 17 kpc and spans at least 18 deg × 15 deg in the sky. As one of the possible scenarios to explain that feature, we propose that the unveiled system is part of Monoceros explained as a density wave moving towards the outer Milky Way. Alternatively, the unveiled system might be connected with other known halo substructures or associated with the progenitor dwarf galaxy of NGC 1851 and NGC 1904, which are widely considered accreted globular clusters
Reflexiones sobre los retos y oportunidades de la educación híbrida
3er Coloquio Fortalecimiento de los Colectivos de Docencia.Reconociendo que esta educación tiene características y metodologías pedagógicas diferentes a las presenciales, de cara al futuro hay que pensar en un formato híbrido que combine la noción presencial y la noción virtual de manera funcional. La modalidad actual funciona como respuesta a una emergencia, pero hay que desarrollar estrategias que sostengan este nuevo modelo en el mediano plazo. Integrantes del Colectivo de Docencia de Diseño Industrial del Departamento de Evaluación, nos reunimos en conferencia vía zoom, para discurrir sobre el tema. Algunas de las reflexiones se integran a la presentación en forma directa con el fin de evitar cualquier mala interpretación relacionada a las propuestas y sugerencias
Revisión bibliográfica sobre desarrollo y validación de un sistema automatizado para invernaderos
Abstract: In western Huila (Colombia) the agricultural sector in greenhouse crops shows a low use of technology. There is a need to develop jobs that allow farmers improve crop conditions in greenhouses, implementing new low–cost technologies that increase crop performance. The objective of this bibliographic revision is to establish the state of the art, in order to structure the project “Validation of an automatized greenhouse system to improve the tomato crop’s productivity in La Plata, Huila”. Scientific articles from specialized databases and technical documents were reviewed from state entities devoted to agricultural research were reviewed with the aim of learning about national and international research about the design, methodology and system development, control models and automatization applied to precision agriculture, production of tomato’s under cover crops in controlled environments and agroecologic conditions included their respective cost and prices in the colombian market. The results of the review show in detail the metodology, development platforms, electronic devices, variety of selected tomatoes, type of greenhouse and watering systems that will be used for the development of the project previously mentioned.Resumen: En el Occidente del Huila (Colombia) se evidencia baja utilización de tecnología por parte del sector agrícola en los cultivos manejados bajo invernadero; se hace necesario desarrollar trabajos que permitan al agricultor mejorar las condiciones de los cultivos bajo cubierta, implementando nuevas tecnologías a menor costo que incrementen el rendimiento de sus cultivos. El objetivo de la presente revisión bibliográfica es establecer el estado del arte, con el fin de estructurar el proyecto Validación de un sistema automatizado de invernadero para mejorar el rendimiento del cultivo de tomate en La Plata, Huila. Se consultaron artículos científicos en bases de datos especializadas y documentos técnicos de entidades estatales dedicadas a la investigación en temas agropecuarios, con el fin de conocer trabajos a nivel nacional e internacional realizados sobre metodologías de diseño y desarrollo de sistemas, modelos de control y automatización aplicados en agricultura de precisión, producción de tomate bajo cubierta en ambientes controlados y condiciones agroecológicas con sus respectivos costos y precios en el mercado colombiano. Los resultados de dicha revisión presentan, de manera detallada, la metodología, plataformas de desarrollo, dispositivos electrónicos, variedad de tomate seleccionado, tipo de invernadero y riego, datos que se utilizarán para el desarrollo del proyecto mencionado
Prediction of the shear strength of reinforced masonry walls using a large experimental database and artificial neural networks
This paper analyses the accuracy of a selection of expressions currently available to estimate the in-plane shear strength of reinforced masonry (RM) walls, including those presented in some international masonry codes. For this purpose, predictions of such expressions are compared with a set of xperimental results reported in the literature. The experimental database includes specimens built with ceramic bricks and concrete blocks tested in partially and fully grouted conditions, which typically present a shear failure mode. Based on the experimental data collected and using artificial neural networks (ANN), this paper presents alternative expressions to the different existing methods to predict the in-plane shear strength of RM walls. The wall aspect ratio, the axial pre-compression level on the wall, the compressive strength of masonry, as well as the amount and spacing of vertical and horizontal reinforcement throughout the wall are taken into consideration as the input parameters for the proposed expressions. The results obtained show that ANN-based proposals give good predictions and in general fit the experimental results better than other calculation methods.This work was supported by the Fondo Nacional de Ciencia y Tecnologia de Chile, (Fondecyt de Iniciacion) [grant number 11121161].Aguilar, V.; Sandoval, C.; Adam Martínez, JM.; Garzón-Roca, J.; Valdebenito, G. (2016). Prediction of the shear strength of reinforced masonry walls using a large experimental database and artificial neural networks. Structure and Infrastructure Engineering. 12(12):1661-1674. https://doi.org/10.1080/15732479.2016.1157824S16611674121
A multiproxy study distinguishes environmental change from diagenetic alteration in the recent sedimentary record of the inner Cadiz Bay (SW Spain)
In this study, we reconstruct the recent environmental evolution of the inner Cadiz Bay using sedimentary records reaching back as far as AD 1700. We report lithological descriptions of the sediments and extensive mineralogical and geochemical analyses. An extraction technique that identifies different Fe phases provides an assessment of diagenetic alteration, which allows an estimation of the original organic matter inputs to the inner Cadiz Bay. Downcore variations in Corg/N ratios, δ13Corg and δ15N are related to changes in organic matter sources and the trophic state of the water column. The downcore records of selected trace metals (e.g. Pb, Zn and Cu) are interpreted to reflect changes in heavy metal pollution in the bay, while records of other elements (e.g. Mn and P) are likely overprinted by diagenetic alteration. Major environmental shifts took place during the 20th century, when the population around Cadiz Bay increased exponentially. Increases in sediment accumulation rates, organic matter inputs and heavy metal contents, in parallel with increases in δ13Corg and δ15N over this period, are interpreted as direct effects of the increasing anthropogenic influence in the area. The results of this study suggest that multiproxy approaches and detailed consideration of diagenetic overprinting are required to reconstruct past environmental conditions from coastal sediments
Magnesium Inhibits Wnt/β-Catenin Activity and Reverses the Osteogenic Transformation of Vascular Smooth Muscle Cells
Magnesium reduces vascular smooth muscle cell (VSMC) calcification in vitro but the mechanism has not been revealed so far. This work used only slightly increased magnesium levels and aimed at determining: a) whether inhibition of magnesium transport into the cell influences VSMC calcification, b) whether Wnt/β-catenin signaling, a key mediator of osteogenic differentiation, is modified by magnesium and c) whether magnesium can influence already established vascular calcification. Human VSMC incubated with high phosphate (3.3 mM) and moderately elevated magnesium (1.4 mM) significantly reduced VSMC calcification and expression of the osteogenic transcription factors Cbfa-1 and osterix, and up-regulated expression of the natural calcification inhibitors matrix Gla protein (MGP) and osteoprotegerin (OPG). The protective effects of magnesium on calcification and expression of osteogenic markers were no longer observed in VSMC cultured with an inhibitor of cellular magnesium transport (2-aminoethoxy-diphenylborate [2-APB]). High phosphate induced activation of Wnt/β-catenin pathway as demonstrated by the translocation of β-catenin into the nucleus, increased expression of the frizzled-3 gene, and downregulation of Dkk-1 gene, a specific antagonist of the Wnt/β-catenin signaling pathway. The addition of magnesium however inhibited phosphate-induced activation of Wnt/β-catenin signaling pathway. Furthermore, TRPM7 silencing using siRNA resulted in activation of Wnt/β-catenin signaling pathway. Additional experiments were performed to test the ability of magnesium to halt the progression of already established VSMC calcification in vitro. The delayed addition of magnesium decreased calcium content, down-regulated Cbfa-1 and osterix and up-regulated MGP and OPG, when compared with a control group. This effect was not observed when 2-APB was added. In conclusion, magnesium transport through the cell membrane is important to inhibit VSMC calcification in vitro. Inhibition of Wnt/β-catenin by magnesium is one potential intracellular mechanism by which this anti-calcifying effect is achieved
Knowledge to Serve the City: Insights from an Emerging Knowledge-Action Network to Address Vulnerability and Sustainability in San Juan, Puerto Rico
This paper presents initial efforts to establish the San Juan Urban Long-Term Research Area Exploratory (ULTRA-Ex), a long-term program aimed at developing transdisciplinary social-ecological system (SES) research to address vulnerability and sustainability for the municipality of San Juan. Transdisciplinary approaches involve the collaborations between researchers, stakeholders, and citizens to produce socially-relevant knowledge and support decision-making. We characterize the transdisciplinary arrangement emerging in San Juan ULTRA-Ex as a knowledge-action network composed of multiple formal and informal actors (e.g., scientists, policymakers, civic organizations and other stakeholders) where knowledge, ideas, and strategies for sustainability are being produced, evaluated, and validated. We describe in this paper the on-the-ground social practices and dynamics that emerged from developing a knowledge-action network in our local context. Specifically, we present six social practices that were crucial to the development of our knowledge-action network: 1) understanding local framings; 2) analyzing existing knowledge-action systems in the city; 3) framing the social-ecological research agenda; 4) collaborative knowledge production and integration; 5) boundary objects and practices; and 6) synthesis, application, and adaptation. We discuss key challenges and ways to move forward in building knowledge-action networks for sustainability. Our hope is that the insights learned from this process will stimulate broader discussions on how to develop knowledge for urban sustainability, especially in tropical cities where these issues are under-explored
Residuos β-lactámicos y tetraciclinas en la leche fresca adquirida por Comités de Vaso de Leche de los distritos de San Jerónimo y Andahuaylas, Apurímac, Perú
The aim of this study was to evaluate the effect of the presence of residues of β- lactam antibiotics and tetracyclines, as well as the physicochemical properties of fresh milk acquired by the Glass of Milk Committees of two districts of Apurimac, Peru. Triplicate milk samples were analyzed from 37 and 32 committees in the districts of San Jerónimo and Andahuaylas respectively. Density, acidity, pH, total solids (TS) and alcohol test were determined and compared with the Peruvian Technical Standards (NTP) for fresh milk. The presence of β-lactam and tetracycline antibiotic compounds was determined through the Betastar® colorimetric kit. The physicochemical properties were correlated with the presence of antibiotics through the Pearson coefficient. A principal component analysis (PCA) was performed. Results showed that 10.8% of the milk samples from the San Jerónimo committees were positive for tetracycline, while 9.4 and 3.1% of the San Jerónimo and Andahuaylas committees, respectively, were positive for β-lactams. A high percentage of milk samples were outside the ranges established by the NTP for density, pH, acidity and TS. The PCA analysis shows that acidity and density are the main variables that would would determine the presence of antibiotics.El objetivo del trabajo fue evaluar el efecto de la presencia de residuos de antibióticos β-lactámicos y tetraciclinas, así como las propiedades fisicoquímicas de la leche fresca adquirida por los Comités de Vaso de Leche de dos distritos de Apurímac, Perú. Se analizaron muestras de leche por triplicado, provenientes de 37 y 32 comités de los distritos de San Jerónimo y Andahuaylas, respectivamente. Se determinaron las propiedades fisicoquímicas: densidad, acidez, pH, sólidos totales (ST) y prueba de alcohol, las cuales se compararon con las Normas Técnicas Peruanas (NTP) para leche fresca. La presencia de compuestos antibióticos β-lactámicos y tetraciclinas se determinó a través del kit colorimétrico Betastar®. Las propiedades fisicoquímicas se correlacionaron con la presencia de antibióticos a través del coeficiente de Pearson. Se realizó un análisis de componentes principales (ACP). El 10.8% de las muestras de leche provenientes de los comités de San Jerónimo fue positivo para tetraciclina, mientras que el 9.4 y 3.1% de los comités de San Jerónimo y Andahuaylas, respectivamente, fueron positivos para β- lactámicos. Un alto procentaje de las muestras de leche estuvieron fuera de los rangos establecidos por las NTP para densidad, pH, acidez y ST. Del análisis ACP se desprende que la acidez y la densidad son las principales variables que pemitirían determinar la presencia de antibioticos
- …