184 research outputs found

    El siglo XVI en novelas y cuentos históricos peruanos contemporáneos

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    A través de una serie de relatos históricos de escritores peruanos, se explican las principales características de este tipo de narrativa en el Perú contemporáneo, empezando por el interés de los autores por el período colonial, y, dentro de él, por el siglo XVI. En el análisis queda patente la importancia concedida al primer siglo de la Colonia, como momento de forja de la identidad peruana, así como la calidad de algunos de estos relatos, poco conocidos fuera del Perú. This article analyses the main features of the historical tales and contemporary novels in peru. The writers of these works have been attracted by this colonial period, especially, the Sixteenth Century. This analysis shows the importance of this period as the moment in which Peruvian identify is formed

    What money cannot buy : a new approach to measure venture capital ability to add non-financial resources

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    Grounding our work on the resource-based view of the firm, we study and quantify the impact of non-financial resources added by venture capital (VC) on the growth performance of investee companies. While most of the literature compares VC-backed companies with similar companies that did not receive external financing, our originality stems from the use of a counterfactual of companies that received external quasi-equity financing (in the form of participative loans) but not non-financial resources. We use a difference-in-difference (DD) estimator to disentangle the effect of an injection of financial resources (which can be used by companies to acquire non-financial resources) from the contribution of the unique non-financial resources brought in by VC (which companies cannot otherwise acquire). Our results are based on a large sample of young Spanish SMEs that received either VC (915) or participative loans (1551) between 2005 and 2013 as first type of financing. We find that the contribution of the non-financial resources leads to yearly increases of 12.86% in employment, 38.13% in total assets, and 54.03% in sales. Furthermore, we find that only the most experienced VC firms contribute with valuable non-financial resources

    Los Contemporáneos: vanguardia poética mexicana

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    El artículo analiza el surgimiento del grupo de poetas, las claves para considerarlos grupo o generación, sus colaboraciones en revistas literarias, especialmente en la que les da el nombre, Contemporáneos (1928-1931), los rasgos vanguardistas de sus producciones y la polémica que se organizó en torno a ellos por la ausencia del tema político-social en sus obras durante la época que florece la novela de la Revolución mexicana y grupos de poesía comprometida. The article analyses the appearance of this group of poets, the keys to consider them a group or a generation, their collaborations in literary magazines—specially in the one that gives them their name: Contemporáneos (1928-1931)—, the avant-garde features of their production and the polemic organized around them because of the absence of the social and political theme in their works during a period in which the novel of the Mexican Revolution and groups of committed poetry were flourishing

    An Autonomous Robotic System for Mapping Abandoned Mines

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    We present the software architecture of a robotic system for mapping abandoned mines. The software is capable of acquiring consistent 2D maps of large mines with many cycles, represented as Markov random fields. 3D C-space maps are acquired from local 3D range scans, which are used to identify navigable paths using A* search. Our system has been deployed in three abandoned mines, two of which inaccessible to people, where it has acquired maps of unprecedented detail and accuracy

    Multi-target genome editing reduces polyphenol oxidase activity in wheat (Triticum aestivum L.) grains

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    Introduction: Polyphenol oxidases (PPO) are dual activity metalloenzymes that catalyse the production of quinones. In plants, PPO activity may contribute to biotic stress resistance and secondary metabolism but is undesirable for food producers because it causes the discolouration and changes in flavour profiles of products during post-harvest processing. In wheat (Triticum aestivum L.), PPO released from the aleurone layer of the grain during milling results in the discolouration of flour, dough, and end-use products, reducing their value. Loss-of-function mutations in the PPO1 and PPO2 paralogous genes on homoeologous group 2 chromosomes confer reduced PPO activity in the wheat grain. However, limited natural variation and the proximity of these genes complicates the selection of extremely low-PPO wheat varieties by recombination. The goal of the current study was to edit all copies of PPO1 and PPO2 to drive extreme reductions in PPO grain activity in elite wheat varieties. Results: A CRISPR/Cas9 construct with one single guide RNA (sgRNA) targeting a conserved copper binding domain was used to edit all seven PPO1 and PPO2 genes in the spring wheat cultivar ‘Fielder’. Five of the seven edited T1 lines exhibited significant reductions in PPO activity, and T2 lines had PPO activity up to 86.7% lower than wild-type. The same construct was transformed into the elite winter wheat cultivars ‘Guardian’ and ‘Steamboat’, which have five PPO1 and PPO2 genes. In these varieties PPO activity was reduced by >90% in both T1 and T2 lines. In all three varieties, dough samples from edited lines exhibited reduced browning. Discussion: This study demonstrates that multi-target editing at late stages of variety development could complement selection for beneficial alleles in cropbreeding programs by inducing novel variation in loci inaccessible to recombinatio

    Trained Immunity Confers Prolonged Protection From Listeriosis.

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    Trained immunity refers to the ability of the innate immune system exposed to a first challenge to provide an enhanced response to a secondary homologous or heterologous challenge. We reported that training induced with β-glucan one week before infection confers protection against a broad-spectrum of lethal bacterial infections. Whether this protection persists over time is unknown. To tackle this question, we analyzed the immune status and the response to Listeria monocytogenes (L. monocytogenes) of mice trained 9 weeks before analysis. The induction of trained immunity increased bone marrow myelopoiesis and blood counts of Ly6C <sup>high</sup> inflammatory monocytes and polymorphonuclear neutrophils (PMNs). Ex vivo, whole blood, PMNs and monocytes from trained mice produced increased levels of cytokines in response to microbial products and limited the growth of L. monocytogenes. In vivo, following challenge with L. monocytogenes, peripheral blood leukocytes were massively depleted in control mice but largely preserved in trained mice. PMNs were reduced also in the spleen from control mice, and increased in the spleen of trained mice. In transwell experiments, PMNs from trained mice showed increased spontaneous migration and CXCL2/MIP2α-induced chemotaxis, suggesting that training promotes the migration of PMNs in peripheral organs targeted by L. monocytogenes. Trained PMNs and monocytes had higher glycolytic activity and mitochondrial respiration than control cells when exposed to L. monocytogenes. Bacterial burden and dissemination in blood, spleen and liver as well as systemic cytokines and inflammation (multiplex bead assay and bioluminescence imaging) were reduced in trained mice. In full agreement with these results, mice trained 9 weeks before infection were powerfully protected from lethal listeriosis. Altogether, these data suggest that training increases the generation and the antimicrobial activity of PMNs and monocytes, which may confer prolonged protection from lethal bacterial infection

    Mammalian Innate Immune Response to a Leishmania-Resident RNA Virus Increases Macrophage Survival to Promote Parasite Persistence.

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    Some strains of the protozoan parasite Leishmania guyanensis (L.g) harbor a viral endosymbiont called Leishmania RNA virus 1 (LRV1). LRV1 recognition by TLR-3 increases parasite burden and lesion swelling in vivo. However, the mechanisms by which anti-viral innate immune responses affect parasitic infection are largely unknown. Upon investigating the mammalian host's response to LRV1, we found that miR-155 was singularly and strongly upregulated in macrophages infected with LRV1+ L.g when compared to LRV1- L.g. LRV1-driven miR-155 expression was dependent on TLR-3/TRIF signaling. Furthermore, LRV1-induced TLR-3 activation promoted parasite persistence by enhancing macrophage survival through Akt activation in a manner partially dependent on miR-155. Pharmacological inhibition of Akt resulted in a decrease in LRV1-mediated macrophage survival and consequently decreased parasite persistence. Consistent with these data, miR-155-deficient mice showed a drastic decrease in LRV1-induced disease severity, and lesional macrophages from these mice displayed reduced levels of Akt phosphorylation

    Microglia control glutamatergic synapses in the adult mouse hippocampus

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    Microglia cells are active players in regulating synaptic development and plasticity in the brain. However, how they influence the normal functioning of synapses is largely unknown. In this study, we characterized the effects of pharmacological microglia depletion, achieved by administration of PLX5622, on hippocampal CA3-CA1 synapses of adult wild type mice. Following microglial depletion, we observed a reduction of spontaneous and evoked glutamatergic activity associated with a decrease of dendritic spine density. We also observed the appearance of immature synaptic features and higher levels of plasticity. Microglia depleted mice showed a deficit in the acquisition of the Novel Object Recognition task. These events were accompanied by hippocampal astrogliosis, although in the absence ofneuroinflammatory condition. PLX-induced synaptic changes were absent in Cx3cr1−/− mice, highlighting the role of CX3CL1/CX3CR1 axis in microglia control of synaptic functioning. Remarkably, microglia repopulation after PLX5622 withdrawal was associated with the recovery of hippocampal synapses and learning functions. Altogether, these data demonstrate that microglia contribute to normal synaptic functioning in the adult brain and that their removal induces reversible changes in organization and activity of glutamatergic synapses

    Lipolysis drives expression of the constitutively active receptor GPR3 to induce adipose thermogenesis

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    Thermogenic adipocytes possess a therapeutically appealing, energy-expending capacity, which is canonically cold-induced by ligand-dependent activation of β-adrenergic G protein-coupled receptors (GPCRs). Here, we uncover an alternate paradigm of GPCR-mediated adipose thermogenesis through the constitutively active receptor, GPR3. We show that the N terminus of GPR3 confers intrinsic signaling activity, resulting in continuous Gs-coupling and cAMP production without an exogenous ligand. Thus, transcriptional induction of Gpr3 represents the regulatory parallel to ligand-binding of conventional GPCRs. Consequently, increasing Gpr3 expression in thermogenic adipocytes is alone sufficient to drive energy expenditure and counteract metabolic disease in mice. Gpr3 transcription is cold-stimulated by a lipolytic signal, and dietary fat potentiates GPR3-dependent thermogenesis to amplify the response to caloric excess. Moreover, we find GPR3 to be an essential, adrenergic-independent regulator of human brown adipocytes. Taken together, our findings reveal a noncanonical mechanism of GPCR control and thermogenic activation through the lipolysis-induced expression of constitutively active GPR3
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