Filtrado de spam mediante ajuste lineal por cuadrados mínimos

Fil: Vega, Daniel Mario. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Computación; ArgentinaFil: Alvarez Alonso, Pablo Alejandro. Universidad de Buenos Aires. Sistema de Bibliotecas y de Informacion; ArgentinaUn problema creciente en las comunicaciones mediante correo electrónico es la práctica de utilizar este medio para el envío de mensajes publicitarios masivos no solicitados, mejor conocidos como "Spam". Distintas soluciones han sido propuestas para atacar este problema, como ser la utilización de técnicas de aprendizaje automático. En este trabajo de tesis, analizaremos un método de clasificación y filtrado basado en ajuste lineal por cuadrados mínimos (LLSF) (YAN/94) en la tarea de filtrado de Spam. Analizaremos distintas variantes y mejoras sobre el algoritmo básico. Entre ellas presentaremos una nueva fórmula de selección de atributos, nuevas alternativas en la representación de los mensajes, un método matemático de determinación del umbral. Finalmente comparemos los resultados con los obtenidos en trabajos anteriores, los cuales utilizaron el algoritmo de Naïve-Bayes (AND/00b)

El papel de la técnica en la configuración de la idea de historia universal

El presente trabajo tiene como objetivo realizar un análisis de la historiografía de la técnica utilizada como principio de explicación global de la idea de historia universal. La metodología empleada es la del análisis y crítica de la obra de los autores en los que la técnica ocupa un papel director o protagonista en las construcciones de la historia universal, como motor o hilo conductor que dota de sentido u ordena el devenir de la historia, así como de los autores en los que los anteriores encuentran el germen de sus ideas

Does the accumulation of creative capital influence the competitiveness of the tourism sector in European regions?

Producción CientíficaRecently, more countries have implemented policies aimed at enhancing the synergy between two strategic sectors: tourism and the creative industries. This article assesses this relationship for a sample of European regions (171 regions). Our main contribution lies in assessing how the accumulation of resources linked to the cultural and creative sectors helps to maximize tourism competitiveness—measured by means of an efficiency model. From a methodological point of view, we apply a two-stage model. First, we construct a tourism efficiency indicator and five synthetic indicators of creativity by means of data envelopment analysis. Secondly, we test the influence of the accumulation of creative industries on regions’ tourism competitiveness by means of a regression analysis. The results can be used to draw conclusions which are applicable in the field of management so that destinations can find competitive advantages for their tourism sector and thus enhance their cultural and creative capita

Finite (Hausdorff) dimension of plants and roots as indicator of ontogeny

The architecture of plants responds to endogenous processes and to the influence of environmental factors. The allometric study of architecture has been a challenge for biology. We define a new finite (Hausdorff) dimension of plants, that considers both the aerial part and the roots, and compute examples. This new finite dimension was introduced recently and, in contrast to the classical Hausdorff dimension, is not zero on finite sets. We propose the finite dimension, as a function of time, as a "signature" of the plant or root. Our first results suggest that the signature is specific to each plant species and its growth period, and constitutes an objective metric that allows to study its ontogenesis in detail.The architecture of plants responds to endogenous processes and to the influence of environmental factors. The allometric study of architecture has been a challenge for biology. We define a new finite (Hausdorff) dimension of plants, that considers both the aerial part and the roots, and compute examples. This new finite dimension was introduced recently and, in contrast to the classical Hausdorff dimension, is not zero on finite sets. We propose the finite dimension, as a function of time, as a "signature" of the plant or root. Our first results suggest that the signature is specific to each plant species and its growth period, and constitutes an objective metric that allows to study its ontogenesis in detail

Reduced order modeling of three dimensional external aerodynamic flows

A method is presented to construct computationally efficient reduced-order models (ROMs) of three-dimensional aerodynamic flows around commercial aircraft components. The method is based on the proper orthogonal decomposition (POD) of a set of steady snapshots, which are calculated using an industrial solver based on some Reynolds averaged Navier-Stokes (RANS) equations. The POD-mode amplitudes are calculated by minimizing a residual defined from the Euler equations, even though the snapshots themselves are calculated from viscous equations. This makes the ROM independent of the peculiarities of the solver used to calculate the snapshots. Also, both the POD modes and the residual are calculated using points in the computational mesh that are concentrated in a close vicinity of the aircraft, which constitute a much smaller number than the total number of mesh points. Despite these simplifications, the method provides quite good approximations of the flow variables distributions in the whole computational domain, including the boundary layer attached to the aircraft surface and the wake. Thus, the method is both robust and computationally efficient, which is checked considering the aerodynamic flow around a horizontal tail plane, in the transonic range 0.4?Mach number?0.8, ?3°?angle of attack?3°

Dimensión finita (de Hausdorff) de plantas y raíces como indicador de ontogenia

La arquitectura de las plantas responde a procesos endógenos y a la influencia de factores ambientales. El estudio alométrico de la arquitectura ha sido un desafío para los biólogos. En este trabajo definimos una nueva dimensión finita (de Hausdorff) de plantas, considerando su parte aérea y de raíces y calculamos algunos ejemplos. Esta nueva dimensión finita fue introducida recientemente y, a diferencia de la dimensión clásica de Hausdorff, no es cero en conjuntos finitos. Proponemos que la dimensión finita, como función del tiempo, es una "firma" de la planta o raíz. Nuestros primeros resultados sugieren que la firma es específica para cada especie de planta y su período de crecimiento, y constituye una métrica objetiva que permite estudiar detalladamente la ontogénesis.The architecture of plants responds to endogenous processes and to the influence of environmental factors. The allometric study of architecture has been a challenge for biology. We define a new finite (Hausdorff) dimension of plants, that considers both the aerial part and the roots, and compute examples. This new finite dimension was introduced recently and, in contrast to the classical Hausdorff dimension, is not zero on finite sets. We propose the finite dimension, as a function of time, as a "signature" of the plant or root. Our first results suggest that the signature is specific to each plant species and its growth period, and constitutes an objective metric that allows to study its ontogenesis in detail.Fil: Alonso, Juan M.. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi". Universidad Nacional de San Luis. Facultad de Ciencias Físico, Matemáticas y Naturales. Instituto de Matemática Aplicada de San Luis "Prof. Ezio Marchi"; ArgentinaFil: Alvarez, Juan Agustin. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Vega Riveros, Cecilia Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Villagra, Pablo Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Ciencias Biológicas; Argentin

PHF2 regulates homology-directed DNA repair by controlling the resection of DNA double strand breaks

Post-translational histone modifications and chromatin remodelling play a critical role controlling the integrity of the genome. Here, we identify histone lysine demethylase PHF2 as a novel regulator of the DNA damage response by regulating DNA damage-induced focus formation of 53BP1 and BRCA1, critical factors in the pathway choice for DNA double strand break repair. PHF2 knockdown leads to impaired BRCA1 focus formation and delays the resolution of 53BP1 foci. Moreover, irradiation-induced RPA phosphorylation and focus formation, as well as localization of CtIP, required for DNA end resection, to sites of DNA lesions are affected by depletion of PHF2. These results are indicative of a defective resection of double strand breaks and thereby an impaired homologous recombination upon PHF2 depletion. In accordance with these data, Rad51 focus formation and homology-directed double strand break repair is inhibited in cells depleted for PHF2. Importantly, we demonstrate that PHF2 knockdown decreases CtIP and BRCA1 protein and mRNA levels, an effect that is dependent on the demethylase activity of PHF2. Furthermore, PHF2-depleted cells display genome instability and are mildly sensitive to the inhibition of PARP. Together these results demonstrate that PHF2 promotes DNA repair by homologous recombination by controlling CtIP-dependent resection of double strand breaks.España Ministerio de Ciencia e Innovacion SAF2016-80626-REspaña, Fundación Canaria Instituto de Investigación Sanitaria de Canarias (FIISC) [PIFUN16/18

Transcriptome analysis of perirenal fat from Spanish Assaf suckling lamb carcasses showing different levels of kidney knob and channel fat

[EN] Introduction: Suckling lamb meat is highly appreciated in European Mediterranean countries because of its mild flavor and soft texture. In suckling lamb carcasses, perirenal and pelvic fat depots account for a large fraction of carcass fat accumulation, and their proportions are used as an indicator of carcass quality. Material and Methods: This study aimed to characterize the genetic mechanisms that regulate fat deposition in suckling lambs by evaluating the transcriptomic differences between Spanish Assaf lambs with significantly different proportions of kidney knob and channel fat (KKCF) depots in their carcasses (4 High-KKCF lambs vs. 4 Low-KKCF lambs). Results: The analyzed fat tissue showed overall dominant expression of white adipose tissue gene markers, although due to the young age of the animals (17–36 days), the expression of some brown adipose tissue gene markers (e.g., UCP1, CIDEA) was still identified. The transcriptomic comparison between the High-KKCF and Low-KKCF groups revealed a total of 80 differentially expressed genes (DEGs). The enrichment analysis of the 49 DEGs with increased expression levels in the Low-KKCF lambs identified significant terms linked to the biosynthesis of lipids and thermogenesis, which may be related to the higher expression of the UCP1 gene in this group. In contrast, the enrichment analysis of the 31 DEGs with increased expression in the High-KKCF lambs highlighted angiogenesis as a key biological process supported by the higher expression of some genes, such as VEGF-A and THBS1, which encode a major angiogenic factor and a large adhesive extracellular matrix glycoprotein, respectively. Discussion: The increased expression of sestrins, which are negative regulators of the mTOR complex, suggests that the preadipocyte differentiation stage is being inhibited in the High-KKCF group in favor of adipose tissue expansion, in which vasculogenesis is an essential process. All of these results suggest that the fat depots of the High-KKCF animals are in a later stage of development than those of the Low-KKCF lambs. Further genomic studies based on larger sample sizes and complementary analyses, such as the identification of polymorphisms in the DEGs, should be designed to confirm these results and achieve a deeper understanding of the genetic mechanisms underlying fat deposition in suckling lambsSIThe research described here has been funded by the project EpiMilksheep (RTI2018-093535-B-100) funded by the Spanish Ministry of Science and Innovation. MA-G is funded by a predoctoral fellowship from the Junta de Castilla and León Government and the European Social Fun

A new potential nano-oncological therapy based on polyamino acid nanocapsules

A critical objective in cancer therapy is to reduce the systemic toxicity through the modification of the biodistribution of anticancer drugs. Herein, we disclose a new biodegradable nanocarrier, polyglutamic acid (PGA) nanocapsules, and present the in vivo pharmacokinetics/toxicity proof-of-concept for the anticancer drug plitidepsin. These novel nanocapsules were prepared using a modified solvent displacement technique where the polyamino acid was electrostatically deposited onto the lipid core. The nanocapsules exhibited an average size of 200 nm, a negative zeta potential and a great capacity for the encapsulation of plitidepsin (encapsulation efficiency above 90%). In addition, the nanocapsules could be freeze-dried and showed an adequate stability profile upon storage. Finally, the in vivo proof-of-concept studies performed in mice indicated that the encapsulation provided the drug with a prolonged blood circulation and a significantly reduced toxicity. In fact, the maximum tolerated dose of the nanoencapsulated drug was more than 3 times that of the reference formulation (Cremophor® EL plitidepsin solution). Overall, beyond the value of this specific formulation, the work reported here represents the evidence of the potential of polyamino acid nanocapsules in nano-oncological therapyThe authors would like to acknowledge financial support from CENIT-NANOFAR XS53 project, PharmaMar, Spain, the Ministry of Sciences and Innovation ((CTQ2009-10963), the Xunta de Galicia (Competitive Reference Groups-FEDER funds Ref. 2010/18, and CN2011/037) and the European Commission FP7 EraNet — EuroNanoMed Program-Instituto Carlos III (Lymphotarg proyect, Ref. PS09/02670). Giovanna Lollo has a fellowship from the Ministry of Education of Spain. Marcos Garcia Fuentes acknowledges an Isidro Parga Pondal Fellowship from Xunta de GaliciaS