147 research outputs found
Diseño de una investigación sobre el error de inversión y las bases neuronales subyacentes
La investigación sobre la enseñanza-aprendizaje de resolución de problemas verbales (RPV) se ha abordado desde perspectivas cognitivas o afectivas. Sin embargo, no es habitual tener en cuenta la importancia que tiene el desarrollo cerebral del alumnado en el aprendizaje. Varios estudios de neurociencia han examinado los procesos usados durante la RPV y cómo son adquiridos. Lee et al. (2007) en un estudio con adultos sobre la traducción de enunciados a ecuación, encontró activación en áreas cerebrales del córtex prefrontal y parietal asociadas con la memoria de trabajo y procesos atencionales. Curiosamente, un estudio con adolescentes y adultos durante la práctica de RPV (Qin et al. 2004), muestra que después de la práctica tanto los adultos como los adolescentes tienen una reducción de activación en áreas prefrontales
Plan de negocio para una empresa de resguardo de objetos personales en la ciudad de Trujillo
La presente tesis tiene como objetivo general proponer y desarrollar un plan de negocio para una empresa de resguardo de objetos personales en la ciudad de Trujillo, idea que nace como consecuencia del alto ?ndice de percepci?n de inseguridad en la ciudad y resolver una necesidad de comodidad para el turista durante su estad?a. De ello se desprenden cinco objetivos espec?ficos. El primero consiste en aplicar t?cnicas de investigaci?n de mercado para determinar la oferta y demanda del servicio en la ciudad. En el segundo objetivo se realiza el diagn?stico y planeamiento de lineamientos estrat?gicos para este plan de negocio. El tercero consiste en analizar el desarrollo de factores claves de ?xito, que lo hacen ?nico al negocio. En el cuarto objetivo se desarrolla un plan de marketing de acuerdo a las caracter?sticas de este plan de negocio, analizando los planes estrat?gicos y operativos que permita una aceptaci?n r?pida y sea sostenible en el mercado. Y en el quinto objetivo se desarrolla el estudio de la rentabilidad mediante la evaluaci?n econ?mica para determinar su viabilidad o no a trav?s de indicadores econ?micos como el VAN, la TIR
Propuestas estrat?gicas que promuevan el relanzamiento de la Zona Especial de Desarrollo Paita, 2021-2022
En el presente trabajo de tesis se enfoca en brindar propuestas estrat?gicas que promuevan el relanzamiento de la zona especial de desarrollo (ZED) Paita 2021-2022 la cual se encuentra en el Departamento de Piura en la zona norte del Per?. Como objetivo principal se plantea establecer estrategias que promuevan el relanzamiento de la Zona especial de desarrollo Paita para atraer al empresario nacional y extranjero dentro de la ZED con el fin de impulsar la instalaci?n de empresas privadas nacionales e internacionales permitiendo el crecimiento de la econom?a de la regi?n. La finalidad del trabajo es incentivar y promover el uso de la ZED Paita a trav?s de diversas estrategias tomando como ejemplo los casos de ?xito de otras ZED en otros pa?ses c?mo (China, M?xico, entre otros) debido a que las ZED suman valor a las econom?as ayudando a su crecimiento y desarrollo. Para poder establecer las estrategias se elabor? una encuesta a las empresas instaladas dentro de la ZED y se llevaron a cabo entrevistas a expertos y empresarios fuera de la ZED con el fin de realizar un an?lisis e interpretaci?n de los resultados y definir las propuestas estrat?gicas que promuevan el relanzamiento de la ZED Paita
Restored in vivo-like membrane lipidomics positively influence in vitro features of cultured mesenchymal stromal/stem cells derived from human placenta
BACKGROUND: The study of lipid metabolism in stem cell physiology has recently raised great interest. The role of lipids goes beyond the mere structural involvement in assembling extra- and intra-cellular compartments. Nevertheless, we are still far from understanding the impact of membrane lipidomics in stemness maintenance and differentiation patterns. In the last years, it has been reported how in vitro cell culturing can modify membrane lipidomics. The aim of the present work was to study the membrane fatty acid profile of mesenchymal stromal cells (MSCs) derived from human fetal membranes (hFM-MSCs) and to correlate this to specific biological properties by using chemically defined tailored lipid supplements (Refeed®). METHODS: Freshly isolated hFM-MSCs were characterized for their membrane fatty acid composition. hFM-MSCs were cultivated in vitro following a classical protocol and their membrane fatty acid profile at different passages was compared to the profile in vivo. A tailored Refeed® lipid supplement was developed with the aim of reducing the differences created by the in vitro cultivation and was tested on cultured hFM-MSCs. Cell morphology, viability, proliferation, angiogenic differentiation, and immunomodulatory properties after in vitro exposure to the tailored Refeed® lipid supplement were investigated. RESULTS: A significant modification of hFM-MSC membrane fatty acid composition occurred during in vitro culture. Using a tailored lipid supplement, the fatty acid composition of cultured cells remained more similar to their in vivo counterparts, being characterized by a higher polyunsaturated and omega-6 fatty acid content. These changes in membrane composition had no effect on cell morphology and viability, but were linked with increased cell proliferation rate, angiogenic differentiation, and immunomodulatory properties. In particular, Refeed®-supplemented hFM-MSCs showed greater ability to express fully functional cell membrane molecules. CONCLUSIONS: Culturing hFM-MSCs alters their fatty acid composition. A tailored lipid supplement is able to improve in vitro hFM-MSC functional properties by recreating a membrane environment more similar to the physiological counterpart. This approach should be considered in cell therapy applications in order to maintain a higher cell quality during in vitro passaging and to influence the outcome of cell-based therapeutic approaches when cells are administered to patients
Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas
Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN
A diarylamine derived from anthranilic acid inhibits ZIKV replication
Zika virus (ZIKV) is a mosquito-transmitted Flavivirus, originally identified in Uganda in 1947 and recently associated with a large outbreak in South America. Despite extensive efforts there are currently no approved antiviral compounds for treatment of ZIKV infection. Here we describe the antiviral activity of diarylamines derived from anthranilic acid (FAMs) against ZIKV. A synthetic FAM (E3) demonstrated anti-ZIKV potential by reducing viral replication up to 86%. We analyzed the possible mechanisms of action of FAM E3 by evaluating the intercalation of this compound into the viral dsRNA and its interaction with the RNA polymerase of bacteriophage SP6. However, FAM E3 did not act by these mechanisms. In silico results predicted that FAM E3 might bind to the ZIKV NS3 helicase suggesting that this protein could be one possible target of this compound. To test this, the thermal stability and the ATPase activity of the ZIKV NS3 helicase domain (NS3Hel) were investigated in vitro and we demonstrated that FAM E3 could indeed bind to and stabilize NS3Hel
Identification of a sex-linked SNP marker in the salmon louse (Lepeophtheirus salmonis) using RAD sequencing
The salmon louse (Lepeophtheirus salmonis (Krøyer, 1837)) is a parasitic copepod that can, if untreated, cause considerable damage to Atlantic salmon (Salmo salar Linnaeus, 1758) and incurs significant costs to the Atlantic salmon mariculture industry. Salmon lice are gonochoristic and normally show sex ratios close to 1:1. While this observation suggests that sex determination in salmon lice is genetic, with only minor environmental influences, the mechanism of sex determination in the salmon louse is unknown. This paper describes the identification of a sex-linked Single Nucleotide Polymorphism (SNP) marker, providing the first evidence for a genetic mechanism of sex determination in the salmon louse. Restriction site-associated DNA sequencing (RAD-seq) was used to isolate SNP markers in a laboratory-maintained salmon louse strain. A total of 85 million raw Illumina 100 base paired-end reads produced 281,838 unique RAD-tags across 24 unrelated individuals. RAD marker Lsa101901 showed complete association with phenotypic sex for all individuals analysed, being heterozygous in females and homozygous in males. Using an allele-specific PCR assay for genotyping, this SNP association pattern was further confirmed for three unrelated salmon louse strains, displaying complete association with phenotypic sex in a total of 96 genotyped individuals. The marker Lsa101901 was located in the coding region of the prohibitin-2 gene, which showed a sex-dependent differential expression, with mRNA levels determined by RT-qPCR about 1.8-fold higher in adult female than adult male salmon lice. This study's observations of a novel sex-linked SNP marker are consistent with sex determination in the salmon louse being genetic and following a female heterozygous system. Marker Lsa101901 provides a tool to determine the genetic sex of salmon lice, and could be useful in the development of control strategies
Concentração de propriedade e desempenho: um estudo nas empresas brasileiras de capital aberto do setor de energia elétrica
Star clusters near and far; tracing star formation across cosmic time
© 2020 Springer-Verlag. The final publication is available at Springer via https://doi.org/10.1007/s11214-020-00690-x.Star clusters are fundamental units of stellar feedback and unique tracers of their host galactic properties. In this review, we will first focus on their constituents, i.e.\ detailed insight into their stellar populations and their surrounding ionised, warm, neutral, and molecular gas. We, then, move beyond the Local Group to review star cluster populations at various evolutionary stages, and in diverse galactic environmental conditions accessible in the local Universe. At high redshift, where conditions for cluster formation and evolution are more extreme, we are only able to observe the integrated light of a handful of objects that we believe will become globular clusters. We therefore discuss how numerical and analytical methods, informed by the observed properties of cluster populations in the local Universe, are used to develop sophisticated simulations potentially capable of disentangling the genetic map of galaxy formation and assembly that is carried by globular cluster populations.Peer reviewedFinal Accepted Versio
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