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Abstract Brain embryonic periventricular endothelial cells (PVEC) crosstalk with neural progenitor cells (NPC) promoting mutual proliferation, formation of tubular-like structures in the former and maintenance of stemness in the latter. To better characterize this interaction, we conducted a comparative transcriptome analysis of mouse PVEC vs. adult brain endothelial cells (ABEC) in mono-culture or NPC co-culture. We identified > 6000 differentially expressed genes (DEG), regardless of culture condition. PVEC exhibited a 30-fold greater response to NPC than ABEC (411 vs. 13 DEG). Gene Ontology (GO) analysis of DEG that were higher or lower in PVEC vs. ABEC identified “Nervous system development” and “Response to Stress” as the top significantly different biological process, respectively. Enrichment in canonical pathways included HIF1A, FGF/stemness, WNT signaling, interferon signaling and complement. Solute carriers (SLC) and ABC transporters represented an important subset of DEG, underscoring PVEC’s implication in blood–brain barrier formation and maintenance of nutrient-rich/non-toxic environment. Our work characterizes the gene signature of PVEC and their important partnership with NPC, underpinning their unique role in maintaining a healthy neurovascular niche, and in supporting brain development. This information may pave the way for additional studies to explore their therapeutic potential in neuro-degenerative diseases, such as Alzheimer’s and Parkinson’s disease. more...

Studies focused solely on single organisms can fail to identify the networks underlying host–pathogen gene-for-gene interactions. Here, we integrate genetic analyses of rice (Oryza sativa, host) and rice blast fungus (Magnaporthe oryzae, pathogen) and uncover a new pathogen recognition specificity of the rice nucleotide-binding domain and leucine-rich repeat protein (NLR) immune receptor Pik, which mediates resistance to M. oryzae expressing the avirulence effector gene AVR-Pik. Rice Piks-1, encoded by an allele of Pik-1, recognizes a previously unidentified effector encoded by the M. oryzae avirulence gene AVR-Mgk1, which is found on a mini-chromosome. AVR-Mgk1 has no sequence similarity to known AVR-Pik effectors and is prone to deletion from the mini-chromosome mediated by repeated Inago2 retrotransposon sequences. AVR-Mgk1 is detected by Piks-1 and by other Pik-1 alleles known to recognize AVR-Pik effectors; recognition is mediated by AVR-Mgk1 binding to the integrated heavy metal-associated (HMA) domain of Piks-1 and other Pik-1 alleles. Our findings highlight how complex gene-for-gene interaction networks can be disentangled by applying forward genetics approaches simultaneously to the host and pathogen. We demonstrate dynamic coevolution between an NLR integrated domain and multiple families of effector proteins. Studies focused solely on single organisms can fail to identify the networks underlying host–pathogen gene-for-gene interactions. Integrating genetic analyses of the pathogen rice blast fungus and its host plant helps to disentangle the complex interactions that determine the outcome of plant-pathogen interactions and reveals a previously overlooked pathogen effector. more...

Este análisis está basado en la teoría de selección de portafolio óptimo, donde se espera que para una rentabilidad determinada dentro de la curva de portafolios eficientes se genere el mínimo nivel de riesgo. En esta investigación se realizó un análisis empírico, en el que se conformó el portafolio eficiente según la teoría de selección de portafolio de Markowitz para los años 2015 a 2020 en los mercados accionarios de México y Colombia, revisando la rentabilidad arrojada para cada año de acuerdo con la composición inicial del portafolio al final del 2015, tomando el punto en la frontera eficiente donde el valor en riesgo (VaR), era igual al VaR del índice COLCAP en el caso de Colombia y al VaR del indicador INMEX en el caso de México. La rentabilidad calculada del portafolio se comparó con la rentabilidad del respectivo índice para validar la teoría en la cual un portafolio eficiente debería ser más rentable que uno no eficiente con el mismo valor en riesgo. El resultado principal es que para el horizonte temporal de cinco años si resultan más rentables los portafolios creados tanto para el mercado accionario de México como para el mercado accionario de Colombia. more...

Cell surface pattern recognition receptors (PRRs) activate immune responses that can include the hypersensitive cell death. However, the pathways that link PRRs to the cell death response are poorly understood. Here, we show that the cell surface receptor-like protein Cf-4 requires the intracellular nucleotide-binding domain leucine-rich repeat containing receptor (NLR) NRC3 to trigger a confluent cell death response upon detection of the fungal effector Avr4 in leaves of Nicotiana benthamiana. This NRC3 activity requires an intact N-terminal MADA motif, a conserved signature of coiled-coil (CC)-type plant NLRs that is required for resistosome-mediated immune responses. A chimeric protein with the N-terminal α1 helix of Arabidopsis ZAR1 swapped into NRC3 retains the capacity to mediate Cf-4 hypersensitive cell death. Pathogen effectors acting as suppressors of NRC3 can suppress Cf-4-triggered hypersensitive cell-death. Our findings link the NLR resistosome model to the hypersensitive cell death caused by a cell surface PRR. more...

A subset of plant NLR immune receptors carry unconventional integrated domains in addition to their canonical domain architecture. One example is rice Pik-1 that comprises an integrated heavy metal-associated (HMA) domain. Here, we reconstructed the evolutionary history of Pik-1 and its NLR partner, Pik-2, and tested hypotheses about adaptive evolution of the HMA domain. Phylogenetic analyses revealed that the HMA domain integrated into Pik-1 before Oryzinae speciation over 15 million years ago and has been under diversifying selection. Ancestral sequence reconstruction coupled with functional studies showed that two Pik-1 allelic variants independently evolved from a weakly binding ancestral state to high-affinity binding of the blast fungus effector AVR-PikD. We conclude that for most of its evolutionary history the Pik-1 HMA domain did not sense AVR-PikD, and that different Pik-1 receptors have recently evolved through distinct biochemical paths to produce similar phenotypic outcomes. These findings highlight the dynamic nature of the evolutionary mechanisms underpinning NLR adaptation to plant pathogens. more...

The molecular codes underpinning the functions of plant NLR immune receptors are poorly understood. We used in vitro Mu transposition to generate a random truncation library and identify the minimal functional region of NLRs. We applied this method to NRC4—a helper NLR that functions with multiple sensor NLRs within a Solanaceae receptor network. This revealed that the NRC4 N-terminal 29 amino acids are sufficient to induce hypersensitive cell death. This region is defined by the consensus MADAxVSFxVxKLxxLLxxEx (MADA motif) that is conserved at the N-termini of NRC family proteins and ~20% of coiled-coil (CC)-type plant NLRs. The MADA motif matches the N-terminal α1 helix of Arabidopsis NLR protein ZAR1, which undergoes a conformational switch during resistosome activation. Immunoassays revealed that the MADA motif is functionally conserved across NLRs from distantly related plant species. NRC-dependent sensor NLRs lack MADA sequences indicating that this motif has degenerated in sensor NLRs over evolutionary time. more...

During plant cell invasion, the oomycete Phytophthora infestans remains enveloped by host-derived membranes whose functional properties are poorly understood. P. infestans secretes a myriad of effector proteins through these interfaces for plant colonization. Recently we showed that the effector protein PexRD54 reprograms host-selective autophagy by antagonising antimicrobial-autophagy receptor Joka2/NBR1 for ATG8CL binding (Dagdas et al., 2016). Here, we show that during infection, ATG8CL/Joka2 labelled defense-related autophagosomes are diverted toward the perimicrobial host membrane to restrict pathogen growth. PexRD54 also localizes to autophagosomes across the perimicrobial membrane, consistent with the view that the pathogen remodels host-microbe interface by co-opting the host autophagy machinery. Furthermore, we show that the host-pathogen interface is a hotspot for autophagosome biogenesis. Notably, overexpression of the early autophagosome biogenesis protein ATG9 enhances plant immunity. Our results implicate selective autophagy in polarized immune responses of plants and point to more complex functions for autophagy than the widely known degradative roles. more...

El presente artículo explica el modelo de gestión del riesgo en proyectos informáticos Mogripi creado a partir de dos enfoques principales: Gestión de Proyectos (PMBOK ®, 2013) y Gestión del Riesgo (PMBOK ®,2013; NTC ISO 31000 ®, 2011; COBIT ®, 2012). En el artículo se utilizará el siguiente esquema: resumen, introducción, metodología, resultados, discusión y referencias. En cuanto a la investigación, en la introducción se explica su propósito e importancia, en la metodología se explica cómo se llevó a cabo, en los resultados se exponen los datos obtenidos y finalmente, en la discusión, se explican los resultados y se compara con el conocimiento previo. La falta de gestión de los riesgos en proyectos informáticos es un agente causante de fracaso en la terminación exitosa de estos. En este sentido, los resultados de validación del modelo Mogripi permitieron establecer que a través de las tres actividades principales: preparar, valorar y tratar los riesgos, se aumenta la posibilidad de alcanzar el cumplimiento de los objetivos del proyecto. La aplicación de los resultados de la investigación se llevó a cabo en la organización Caja de Compensación Familiar de Norte de Santander, Comfanorte. more...

Este artículo describe el diseño de un microcanal rectangular óptimo, construido con grafi to de alta conductividad térmica (HTCG). Para simular el disipador de microcanales propuesto se utilizó el modelo de resistencia térmica total y el criterio de minimización de la generación de entropía. Para solucionar el problema de optimización, se utilizó el algoritmo de enjambre de partículas unifi cado (UPSO). Los resultados mostraron un efecto marcado al utilizar este conductor térmico, en comparación con materiales tradicionales (tales como aluminio), y utilizando aire y amoniaco gaseoso como fl uidos de trabajo. También se reporta el efecto relativo de las resistencias térmicas de constricción, de convección y del fl uido, sobre la resistencia térmica equivalente total. Como un ejemplo demostrativo del efecto causado al cambiar la naturaleza del refrigerante, se seleccionó un nanofl uido de dióxido de titanio. Se encontró que el número de Nusselt es perceptiblemente menor, cuando se utiliza un nanofl uido como refrigerante y cuando el material con que está construido el microcanal es HTCG. more...

This article presents a review in relation to the object of study: Communications Management as an important factor in the management of projects. The review includes the most relevant and most renowned authors in the field of project management, focusing on telecommunications projects, which lets you define a communications management model. more...

Rev.esc.adm.neg Este artículo define un modelo de investigación en el área de gestión de proyectos adaptado dentro de los procesos de investigación en ingeniería, principalmente de la ingeniería del Software, con base en la guía de los fundamentos para la dirección de proyectos (Guía del PMBOK®) y las Bases para las Competencias (NCB) de la Asociación Internacional de Dirección de Proyectos (IPMA). more...

El golpe de Estado de 1973 inaugura en la izquierda chilena, particularmente en el Partido Socialista y el MAPU, un proceso de autocrítica frente a lo realizado durante la Unidad Popular, debido a este proceso se repiensan y reelaboran conceptos fundamentales del acervo teórico de la izquierda, modificando el lenguaje político de la oposición a la dictadura. En este escenario, revisamos las apropiaciones, reelaboraciones y usos conceptuales de la democracia y el socialismo que el líder socialista Ricardo Lagos desarrollo desde la tribuna de lasrevistas políticas opositoras al régimen dictatorial. more...

Copyright of Medicina Interna de Mexico is the property of Colegio de Medicina Interna de Mexico and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...

Copyright of Dyna is the property of Universidad Nacional de Colombia, Medellin, Facultad de Minas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...

Copyright of Revista EAN is the property of Universidad EAN and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...

Por una parte, las revistas enfrentan retos para mantenerse actualizadas y posicionarse en un entorno muy cambiante y competitivo, lo que afecta su relevancia y citaciones; y, por otra parte, la inteligencia artificial (IA) es cada vez más una tecnología clave en la industria editorial, por su capacidad de procesar grandes volúmenes de datos y optimizar procesos. Con el objetivo de identificar la relevancia y el potencial de las herramientas de IA para mejorar los procesos de las publicaciones científicas, así como para identificar tendencias emergentes, este artículo presenta una investigación con un enfoque mixto, que integra una revisión sistemática de la literatura y recopila y analiza datos en publicaciones científicas, particularmente en ciencias sociales. Se revisan las plataformas de IA disponibles, evaluando su precisión a través de revisiones sistemáticas y análisis comparativos y, como resultado, se proponen directrices para su adecuada implementación en procesos editoriales. more...

In plants, nucleotide-binding domain and leucine-rich repeat (NLR)-containing proteins can form receptor networks to confer hypersensitive cell death and innate immunity. One class of NLRs, known as NLR required for cell death (NRCs), are central nodes in a complex network that protects against multiple pathogens and comprises up to half of the NLRome of solanaceous plants. Given the prevalence of this NLR network, we hypothesised that pathogens convergently evolved to secrete effectors that target NRC activities. To test this, we screened a library of 165 bacterial, oomycete, nematode, and aphid effectors for their capacity to suppress the cell death response triggered by the NRC-dependent disease resistance proteins Prf and Rpi-blb2. Among 5 of the identified suppressors, 1 cyst nematode protein and 1 oomycete protein suppress the activity of autoimmune mutants of NRC2 and NRC3, but not NRC4, indicating that they specifically counteract a subset of NRC proteins independently of their sensor NLR partners. Whereas the cyst nematode effector SPRYSEC15 binds the nucleotide-binding domain of NRC2 and NRC3, the oomycete effector AVRcap1b suppresses the response of these NRCs via the membrane trafficking-associated protein NbTOL9a (Target of Myb 1-like protein 9a). We conclude that plant pathogens have evolved to counteract central nodes of the NRC immune receptor network through different mechanisms. Coevolution with pathogen effectors may have driven NRC diversification into functionally redundant nodes in a massively expanded NLR network. more...

El modelo dinámico de un sistema de control de par utilizando cuatro giróscopos (4-CMG) tradicionalmente se obtiene al calcular la derivada de la ecuación del momento angular total. Aunque este enfoque conduce a un modelo dinámico relativamente simple, recientemente se han introducido nuevos modelos debido a términos que no se han tenido en cuenta, o se desprecian, durante el cálculo de la ecuación del momento angular. En este artículo, se propone un nuevo modelo dinámico para un 4-CMG basado en el algoritmo de Newton-Euler, el cual es bien aceptado en robótica. Con este nuevo enfoque se logra obtener un modelo dinámico bastante completo. more...

This article deals with the design of optimum microchannel heat sinks through Unified Particle Swarm Optimisation (UPSO) and Harmony Search (HS). These heat sinks are used for the thermal management of electronic devices, and we analyse the performance of UPSO and HS in their design, both, systematically and thoroughly. The objective function was created using the entropy generation minimisation criterion. In this study, we fixed the geometry of the microchannel, the amount of heat to be removed, and the properties of the cooling fluid. Moreover, we calculated the entropy generation rate, the volume flow rate of air, the channel width, the channel height, and the Knudsen number. The results of several simulation optimizations indicate that both global optimisation strategies yielded similar results, about 0.032 W/K, and that HS required five times more iterations than UPSO, but only about a nineteenth of its computation time. In addition, HS revealed a greater chance (about three times) of finding a better solution than UPSO, but with a higher dispersion rate (about five times). Nonetheless, both algorithms successfully optimised the design for different scenarios, even when varying the material of the heat sink, and for different heat transfer rates. more...