Metallothioneins (MT) are multi-stress proteins mainly involved in metal detoxification. MT gene expression is normally induced by a broad variety of stimulus and its gene expression regulation ...mainly occurs at a transcriptional level. Conserved motifs in the
MT promoters have been described. These motifs show a consensus sequence very similar to AP-1 sites, and bZIP type transcription factors might participate in the MT gene expression regulation. In this research work, we characterize four AP-1 transcription factors in each of four different analyzed
species, detecting a high conservation among them. Each AP-1 molecule has its counterpart in the other three
species. A comparative qRT-PCR analysis of these AP-1 genes have been carried out in different
strains (including metal-adapted, knockout and/or knockdown strains among others), and under different metal-stress conditions (1 or 24 h Cd
, Cu
, or Pb
treatments). The possible interaction of these transcription factors with the conserved AP-1 motifs present in MT promoters has been corroborated by protein-DNA interaction experiments. Certain connection between the expression patterns of the bZIP and MT genes seems to exist. For the first time, and based on our findings, a possible gene expression regulation model including both AP-1 transcription factors and MT genes from the ciliate
has been elaborated.
El objetivo de este artículo es contribuir a las reflexiones sobre la comunicación digital desde una perspectiva dialéctica y dialógica que articule las tradiciones teóricas que permiten analizar los ...problemas comunicativos con los conceptos de hipermediación. Para ello se ponen en diálogo las ideas de Robert Craig y su metamodelo constitutivo compuesto de la integración de siete tradiciones, con los trabajos de Carlos Scolari, quien analiza las nuevas formas de comunicación que surgen de la convergencia entre medios y lenguajes mediante los conceptos de hipermediación, digitalización, hipertextualidad, reticularidad, interactividad y multimedialidad. Tender puentes entre tradiciones e hipermediaciones permite llenar los vacíos teóricos producidos por procesos de investigación que han alternado entre la comunicación de masas y la comunicación interpersonal, al tiempo que se posiciona a la comunicación digital como una estrategia mediadora del diálogo entre las tradiciones.
The aim of this article is to contribute to the reflections on digital communication from a dialectical and dialogical perspective that articulates the theoretical traditions that enable the analysis of communicative problems with the concepts of hypermediation. To this end, the ideas of Robert Craig and his constitutive metamodel formed by the integration of seven traditions are put into dialogue with the ideas of Carlos Scolari, who analyses the new forms of communication that arise from the convergence between media and languages through the concepts of hypermediation, digitalisation, hypertextuality, reticularity, interactivity and multimediality. Building bridges between traditions and hypermediations allows us to fill the theoretical gaps produced by research processes that have alternated between mass communication and interpersonal communication, while at the same time it positions digital communication as a mediating strategy of dialogue between traditions.
Mathematical modelling methods have several limitations when addressing complex physics whose calculations require considerable amount of time. This is the case of adaptive optics, a series of ...techniques used to process and improve the resolution of astronomical images acquired from ground-based telescopes due to the aberrations introduced by the atmosphere. Usually, with adaptive optics the wavefront is measured with sensors and then reconstructed and corrected by means of a deformable mirror. An improvement in the reconstruction of the wavefront is presented in this work, using convolutional neural networks (CNN) for data obtained from the Tomographic Pupil Image Wavefront Sensor (TPI-WFS). The TPI-WFS is a modified curvature sensor, designed for measuring atmospheric turbulences with defocused wavefront images. CNNs are well-known techniques for its capacity to model and predict complex systems. The results obtained from the presented reconstructor, named Convolutional Neural Networks in Defocused Pupil Images (CRONOS), are compared with the results of Wave-Front Reconstruction (WFR) software, initially developed for the TPI-WFS measurements, based on the least-squares fit. The performance of both reconstruction techniques is tested for 153 Zernike modes and with simulated noise. In general, CRONOS showed better performance than the reconstruction from WFR in most of the turbulent profiles, with significant improvements found for the most turbulent profiles; overall, obtaining around 7% of improvements in wavefront restoration, and 18% of improvements in Strehl.
RESUMEN Fundamento: las colectividades humanas cada día son más envejecidas y la población de nefrópatas crónicos crece cada vez más, por lo que la Nefrogeriatría demanda nuevas estrategias de ...superación para los profesionales de la salud. Objetivo: diseñar una estrategia de superación sobre Nefrogeriatría para el mejoramiento del desempeño profesional del médico de familia. Métodos: se realizó una investigación cuasiexperimental entre enero de 2017 a mayo de 2019 en el Policlínico Universitario “5 de Septiembre” del municipio Consolación del Sur, provincia Pinar del Río; Cuba. Se aplicaron métodos teóricos: sistematización, análisis-síntesis, sistémico-estructural-funcional y modelación; empíricos: observación del desempeño profesional, revisión documental y el criterio de expertos; y matemático-estadísticos. Resultados: el diagnóstico realizado permitió identificar carencias en cuanto al nivel de conocimientos sobre la nefroprevención y la atención médica en el paciente nefrogeriátrico en los médicos de familia, por lo que se diseñó una estrategia fundamentada en aspectos filosóficos, sociológicos, psicológicos, de las tecnologías de la información y las comunicaciones, pedagógicos y de la educación médica, la cual fue valorada por criterios de expertos. Conclusiones: la estrategia se caracterizó por ser interdisciplinaria, sistémica, flexible, contextualizada, humanista, factible, con capacidad de aplicabilidad y participación de los actores implicados. La consulta a los expertos corroboró su pertinencia y adecuada estructura metodológica en correspondencia con el diagnóstico y los fundamentos referidos.
The widespread use of inorganic nanomaterials of anthropogenic origin has significantly increased in the last decade, being now considered as emerging pollutants. This makes it necessary to carry out ...studies to further understand their toxicity and interactions with cells. In the present work we analyzed the toxicity of CuO nanotubes (CuONT) in the ciliate Tetrahymena thermophila, a eukaryotic unicellular model with animal biology. CuONT exposure rapidly induced ROS generation in the cell leading to oxidative stress and upregulation of genes encoding antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase), metal-chelating metallothioneins and cytochrome P450 monooxygenases. Comet assays and overexpression of genes involved in DNA repair confirmed oxidative DNA damage in CuONT-treated cells. Remarkably, both electron and fluorescent microscopy revealed numerous lipid droplets and autophagosomes containing CuONT aggregates and damaged mitochondria, indicating activation of macroautophagy, which was further confirmed by a dramatic upregulation of ATG (AuTophaGy related) genes. Treatment with autophagy inhibitors significantly increased CuONT toxicity, evidencing the protective role of autophagy towards CuONT-induced damage. Moreover, increased formation of lipid droplets appears as an additional mechanism of CuONT detoxification. Based on these results, we present a hypothetical scenario summarizing how T. thermophila responds to CuONT toxicity. This study corroborates the use of this ciliate as an excellent eukaryotic microbial model for analyzing the cellular response to stress caused by toxic metal nanoparticles.
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•A wide variety of defense systems were rapidly activated following copper oxide nanotubes (CuONT) in T. thermophila.•Autophagy appeared as the main mechanism to isolate and expel internalized CuONT and CuONT-damaged organelles in Tetrahymena.•The dramatic increase in lipid droplet production suggests a protective role against CuONT-imposed stress in this ciliate.
Multilayer materials have demonstrated to provide an efficient mechanism for toughening by deflection of a propagating crack by weak interlayers. Therefore, the aim of this work is to study the ...colloidal processing of 8 mol% yttria stabilized zirconia (8YSZ) based laminates by intercalating thin layers of graphene enriched with 8YSZ, and to evaluate the advantages of such multilayered structure in the propagation of cracks induced by indentation. Green tapes of 8YSZ and graphene-oxide with YSZ were obtained by aqueous tape casting and sintered in one-step by spark plasma sintering at 1400°C. Microindentation results showed that the indentation cracks propagate within the horizontal direction within the ceramic layer, but in the cross-sectional direction the presence of the GO-rich layers stops the cracks without deflection or bifurcation. The hardness and elastic modulus values were higher than 17.6GPa and 230GPa, respectively, and similar for all layers.
Introducción: La vegetación de costa arenosa ubicada en el Parque Nacional de Guanahacabibes en Cuba, ofrece diversos bienes y servicios ambientales, entre ellos la recreación. Este ecosistema forma ...parte de los senderos ecoturísticos comercializados en el área y ha sido dañado por inundaciones ocasionadas por eventos extremos, como el huracán Wilma en el 2005. Objetivo: Valorar el beneficio recreativo que ofrece la vegetación de costa arenosa y el daño causado por inundaciones costeras. Metodología: Se utilizó una aproximación del método costos de viaje zonal, sin equidistancia, en una muestra de los visitantes que practicaron la actividad del senderismo asociada a la vegetación de costa arenosa, en el año 2016. Resultados: El huracán Wilma produjo inundaciones de moderadas a fuertes que afectaron entre un 70 % a 80 % el área de vegetación de costa arenosa. El impacto negativo que provocó en el ecosistema, tiene alta importancia en la jerarquía de daños. El beneficio recreativo por observar la vegetación de costa arenosa asociada a los senderos ecoturísticos tuvo un valor aproximado de 63 996 USD, para el año 2016, a su vez el valor individual del bienestar fue 15 USD. Conclusiones: Se puede inferir que un huracán similar al Wilma producirá una afectación análoga en la vegetación de costa arenosa y a su vez una posible pérdida de la calidad ambiental, siendo un antecedente el procedimiento utilizado y el valor recreativo estimado para este ecosistema.
Human Machine Interfaces (HMI) principles are for the development of interfaces for assistance or support systems in physiotherapy or rehabilitation processes. One of the main problems is the degree ...of customization when applying some rehabilitation therapy or when adapting an assistance system to the individual characteristics of the users. To solve this inconvenience, it is proposed to implement a database of surface Electromyography (sEMG) of a channel in healthy individuals for pattern recognition through Neural Networks of contraction in the muscular region of the biceps brachii. Each movement is labeled using the One-Hot Encoding technique, which activates a state machine to control the position of an anthropomorphic manipulator robot and validate the response time of the designed HMI. Preliminary results show that the learning curve decreases when customizing the interface. The developed system uses muscle contraction to direct the position of the end effector of a virtual robot. The classification of Electromyography (EMG) signals is obtained to generate trajectories in real time by designing a test platform in LabVIEW.
Summary
Extreme stress situations can induce genetic variations including genome reorganization. In ciliates like Tetrahymena thermophila, the approximately 45‐fold ploidy of the somatic macronucleus ...may enable adaptive responses that depend on genome plasticity. To identify potential genome‐level adaptations related to metal toxicity, we isolated three Tetrahymena thermophila strains after an extended adaptation period to extreme metal concentrations (Cd2+, Cu2+ or Pb2+). In the Cd‐adapted strain, we found a approximately five‐fold copy number increase of three genes located in the same macronuclear chromosome, including two metallothionein genes, MTT1 and MTT3. The apparent amplification of this macronuclear chromosome was reversible and reproducible, depending on the presence of environmental metal. We also analysed three knockout (KO) and/or knockdown (KD) strains for MTT1 and/or MTT5. In the MTT5KD strain, we found at least two new genes arising from paralogous expansion of MTT1, which encode truncated variants of MTT1. The expansion can be explained by a model based on somatic recombination between MTT1 genes on pairs of macronuclear chromosomes. At least two of the new paralogs are transcribed and upregulated in response to Cd2+. Altogether, we have thus identified two distinct mechanisms, both involving genomic plasticity in the polyploid macronucleus that may represent adaptive responses to metal‐related stress.
During the armed conflict in Colombia, homemade improvised antipersonnel landmines were used to neutralize the adversary. Many active artifacts remain buried, causing damage to biodiversity by ...exploding. The extensive literature describes the effects and injuries caused to humans by conventional landmines. However, there is considerably less information on the behavior and effects of homemade antipersonnel landmines on fauna and good field investigation practices. Our objectives were to describe the characteristics of a controlled explosion of a homemade antipersonnel landmine (using ammonium nitrate as an explosive substance), to compare the effectiveness of some evidence search patterns used in forensic investigation, and to determine the effects on a piece of an animal carcass. The explosion generated a shock wave and an exothermic reaction, generating physical effects on the ground and surrounding structures near the point of explosion. The amputation of the foot in direct contact with the device during the explosion and multiple fractures were the main effects on the animal carcass. Finally, it was determined that finding evidence was more effective in a smaller search area. Many factors can influence the results, which must be weighed when interpreting the results, as discussed in this manuscript.
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