Este artículo retoma el concepto de obras expresivas audiovisuales comunitarias y su estrecho vínculo con la recreación. Este estudio parte de algunos resultados del proyecto de investigación. El ...objetivo es visibilizar la importancia de desarrollar procesos educomunicativos de mediano y largo aliento en los que no solo se vinculen lenguajes audiovisuales, sino también otras formas de expresión lúdico-creativas. El enfoque metodológico del proyecto de investigación fue cualitativo, basado en la observación profunda y la descripción densa de la etnografía clásica, así como en la etnografía audiovisual y en la etnografía virtual. Los principales hallazgos, desde la perspectiva de la comunicación basada en las mediaciones, es que las OEAC tienen lugar en el centro mismo de las comunidades, en los usos, las relaciones y los vínculos que se construyen en los procesos de comunicación. Además de funcionar socialmente como mediaciones en el sentido desarrollado por Martín-Barbero (1991), están conformadas por mediaciones semióticas o lenguajes lúdico-creativos (Mesa, 2004). En conclusión, se considera que las OEAC abren posibilidades de transformación social porque desarrollan procesos que trascienden las películas, reconocen los aspectos sociohistóricos, fortalecen la identidad colectiva y hacen posible una fluida relación entre sujetos y contextos.
Several biomaterials, including natural polymers, are used to increase cellular interactions as an effective way to treat bone injuries. Chitosan (CS) is one of the most studied biocompatible natural ...polymers. Graphene oxide (GO) is a carbon-based nanomaterial capable of imparting desired properties to the scaffolds. In the present study, CS and GO were used for scaffold preparation. CS was extracted from the mycelium of the fungus
. On the other hand, GO was synthesized using an improved Hummers-Offemann method and was characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, atomic force microscopy (AFM), X-ray diffraction (XRD), and dynamic light scattering (DLS). Subsequently, three formulations (GO 0%, 0.5%, and 1%) were used to prepare the scaffolds by the freeze-drying technique. The scaffolds were characterized by FTIR, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM), to determine their thermal stability and pore size, demonstrating that their stability increased with the increase of GO amount. Finally, the scaffolds were implanted, recollected 30 days later, and studied with an optical microscope, which evidenced the recovery of the tissue architecture and excellent biocompatibility. Hence, these results strongly suggested the inherent nature of chitosan/graphene oxide (CS/GO) scaffolds for their application in bone tissue regeneration.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Este artículo tiene por objetivo más amplio discutir tanto el concepto de metafuente, acuñado hace tiempo, como el uso de los sistemas de información geográfica en historia. Específicamente buscamos ...destacar el aumento de investigaciones cuya metodología se asocia al geoprocesamiento o a los sistemas de información geográfica y algunas consecuencias de este procedimiento sobre la historia misma.
In flowering plants, fertilization requires complex cell-to-cell communication events between the pollen tube and the female reproductive tissues, which are controlled by extracellular signaling ...molecules interacting with receptors at the pollen tube surface. We found that two such receptors in Arabidopsis, BUPS1 and BUPS2, and their peptide ligands, RALF4 and RALF19, are pollen tube–expressed and are required to maintain pollen tube integrity. BUPS1 and BUPS2 interact with receptors ANXUR1 and ANXUR2 via their ectodomains, and both sets of receptors bind RALF4 and RALF19. These receptor-ligand interactions are in competition with the female-derived ligand RALF34, which induces pollen tube bursting at nanomolar concentrations. We propose that RALF34 replaces RALF4 and RALF19 at the interface of pollen tube–female gametophyte contact, thereby deregulating BUPS-ANXUR signaling and in turn leading to pollen tube rupture and sperm release.
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BFBNIB, NMLJ, NUK, ODKLJ, PNG, SAZU, UL, UM, UPUK
The arylation of 2-alkyl aziridines by nucleophilic ring-opening or transition-metal-catalyzed cross-coupling enables facile access to biologically relevant β-phenethylamine derivatives. However, ...both approaches largely favor C–C bond formation at the less-substituted carbon of the aziridine, thus enabling access to only linear products. Consequently, despite the attractive bond disconnection that it poses, the synthesis of branched arylated products from 2-alkyl aziridines has remained inaccessible. Herein, we address this long-standing challenge and report the first branched-selective cross-coupling of 2-alkyl aziridines with aryl iodides. This unique selectivity is enabled by a Ti/Ni dual-catalytic system. We demonstrate the robustness of the method by a twofold approach: an additive screening campaign to probe functional group tolerance and a feature-driven substrate scope to study the effect of the local steric and electronic profile of each coupling partner on reactivity. Furthermore, the diversity of this feature-driven substrate scope enabled the generation of predictive reactivity models that guided mechanistic understanding. Mechanistic studies demonstrated that the branched selectivity arises from a TiIII-induced radical ring-opening of the aziridine.
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IJS, KILJ, NUK, PNG, UL, UM
Considerando que la gestante y la población general cursan con la misma posibilidad de contagio por SARS COV2; sin embargo, en la actualidad se conoce que el embarazo predispone a cursar con ...expresión grave de la enfermedad, principalmente por la condición protrombótica fisiológica de la gestación, mayor tasa de afectación pulmonar, ingreso a unidades de cuidados intensivos, intubación con vía aérea difícil y riesgo de muerte.
Cell fate specification occurs along invariant species-specific trajectories that define the animal body plan. This process is controlled by gene regulatory networks that regulate the expression of ...the limited set of transcription factors encoded in animal genomes. Here we globally assess the spatial expression of ~90% of expressed transcription factors during sea urchin development from embryo to larva to determine the activity of gene regulatory networks and their regulatory states during cell fate specification. We show that >200 embryonically expressed transcription factors together define >70 cell fates that recapitulate the morphological and functional organization of this organism. Most cell fate-specific regulatory states consist of ~15–40 transcription factors with similarity particularly among functionally related cell types regardless of developmental origin. Temporally, regulatory states change continuously during development, indicating that progressive changes in regulatory circuit activity determine cell fate specification. We conclude that the combinatorial expression of transcription factors provides molecular definitions that suffice for the unique specification of cell states in time and space during embryogenesis.Gene regulatory networks (GRNs) control developmental processes that define the body plan of multicellular animals. In this study, Valencia and Peter monitored the activity of GRNs during embryogenesis in sea urchins by determining the spatial and temporal changes in the expression of over 200 transcription factors.
Los consumidores cada día exigen productos en sus dietas que no solo aporten los nutrientes requeridos para una vida sana, sino que además son de preferencia aquellos que puedan complementar con ...propiedades benéficas para la salud. En las últimas décadas se ha reconocido a la Rosa mosqueta, la Rosa canina y a la Rosa rubiginosa, como frutos que contienen muchas propiedades nutracéuticas. El presente trabajo hace una revisión de los artículos de investigación realizados a la Rosa mosqueta desde un punto de vista de su importancia de su consumo y sus beneficios para la salud; describiendo las características químicas, físicas y bioquímicas tales como el contenido de componentes fenólicos, ácidos grasos, ácido linoleico, minerales; y de otros compuestos importantes también desde el punto de vista industrial, tales como el contenido de antioxidantes, pigmentos, entre otros. De acuerdo a los antecedentes recopilados, la Rosa mosqueta es una fuente de micronutrientes incluyendo la vitamina c y el licopeno, entregando además un buen aporte nutricional; por lo anterior debe ser considerado como un alimento funcional. Aun siendo una especie que crece en estado salvaje, sobre suelos forestales; siendo un frutal menor y una planta medicinal su importancia en el consumo masivo debe ser considerada.
Desde su creación como máxima autoridad monetaria, cambiaria y crediticia, a partir de la Constitución de 1991, la Junta Directiva del Banco de la República es, sin duda, la institución económica más ...respetada y respetable del país. A continuación, se presenta una síntesis de las discusiones y decisiones más relevantes en las últimas tres décadas, pasando por las relaciones y pulsos de la corporación con los gobiernos de turno, hasta las anécdotas de la elección de los codirectores en los períodos presidenciales.
Species that propagate by sexual reproduction actively guard against the fertilization of an egg by multiple sperm (polyspermy). Flowering plants rely on pollen tubes to transport their immotile ...sperm to fertilize the female gametophytes inside ovules. In Arabidopsis, pollen tubes are guided by cysteine-rich chemoattractants to target the female gametophyte
. The FERONIA receptor kinase has a dual role in ensuring sperm delivery and blocking polyspermy
. It has previously been reported that FERONIA generates a female gametophyte environment that is required for sperm release
. Here we show that FERONIA controls several functionally linked conditions to prevent the penetration of female gametophytes by multiple pollen tubes in Arabidopsis. We demonstrate that FERONIA is crucial for maintaining de-esterified pectin at the filiform apparatus, a region of the cell wall at the entrance to the female gametophyte. Pollen tube arrival at the ovule triggers the accumulation of nitric oxide at the filiform apparatus in a process that is dependent on FERONIA and mediated by de-esterified pectin. Nitric oxide nitrosates both precursor and mature forms of the chemoattractant LURE1
, respectively blocking its secretion and interaction with its receptor, to suppress pollen tube attraction. Our results elucidate a mechanism controlled by FERONIA in which the arrival of the first pollen tube alters ovular conditions to disengage pollen tube attraction and prevent the approach and penetration of the female gametophyte by late-arriving pollen tubes, thus averting polyspermy.
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FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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