El método de las fracciones continuas:aplicación al desarrollo de algoritmos eficientes de cálculo de funciones de bessel

En este trabajo se presentan los elementos necesarios sobre el método de las fracciones continuas para entender su uso en el desarrollo de algoritmos de computación eficientes para el cálculo de funciones de Bessel. El enfoque que se da a esta contribución es pedagógico, resaltando los aspectos docentes del método, y pretende ser enmarcada en el ámbito de la enseñanza de las matemáticas y sus aplicaciones en física y/o ingeniería. En ella se ofrece un material didáctico dirigido a profesores de matemáticas que imparten docencia en carreras técnicas en cursos avanzados de cálculo numérico

Homicide Profiles Based on Crime Scene and Victim Characteristics

One of the current trends in homicide research includes developing works based on scientific study and empirical evidence, which offer conclusions that can be used in an operational manner during police investigations. The objective of this study was to identify homicide characteristics from behaviors carried out on the crime scene and victim characteristics associated with those of the perpetrators of these crimes in Spain. The sample consisted of 448 homicide cases from the database of the Homicide Revision Project led by the Office of Coordination and Studies of the Secretary of State and Security. After creating six classification tree models, it was found that the modus operandi of the aggressor and the victim characteristics may permit hypothesizing about the demographic characteristics of the perpetrator (gender, age, and country of origin), his/her criminal record, and the type of relationship with the victim. Furthermore, the importance of the study of victimology during a criminal investigation is highlighted, as it may indirectly offer information about the potential perpetrator. The findings of this study suggest that criminal profiling contributes notably to the decision-making process to establish more rigorous suspect prioritization, improve the management of human resources and materials, and increase the efficiency of criminal investigations

Grid Global Behavior Prediction

Complexity has always been one of the most important issues in distributed computing. From the first clusters to grid and now cloud computing, dealing correctly and efficiently with system complexity is the key to taking technology a step further. In this sense, global behavior modeling is an innovative methodology aimed at understanding the grid behavior. The main objective of this methodology is to synthesize the grid's vast, heterogeneous nature into a simple but powerful behavior model, represented in the form of a single, abstract entity, with a global state. Global behavior modeling has proved to be very useful in effectively managing grid complexity but, in many cases, deeper knowledge is needed. It generates a descriptive model that could be greatly improved if extended not only to explain behavior, but also to predict it. In this paper we present a prediction methodology whose objective is to define the techniques needed to create global behavior prediction models for grid systems. This global behavior prediction can benefit grid management, specially in areas such as fault tolerance or job scheduling. The paper presents experimental results obtained in real scenarios in order to validate this approach

Enhanced Failure Detection Mechanism in MapReduce

The popularity of MapReduce programming model has increased interest in the research community for its improvement. Among the other directions, the point of fault tolerance, concretely the failure detection issue seems to be a crucial one, but that until now has not reached its satisfying level. Motivated by this, I decided to devote my main research during this period into having a prototype system architecture of MapReduce framework with a new failure detection service, containing both analytical (theoretical) and implementation part. I am confident that this work should lead the way for further contributions in detecting failures to any NoSQL App frameworks, and cloud storage systems in general

Expressiveness and Instrumentality of Crime Scene Behavior in Spanish Homicides

One of the current trends in the study of criminal profiling consists of developing theoretical and methodological typologies to offer information of operational use in police investigations. The objective of this work was to verify the validity of the instrumental/expressive model, so as to establish homicide typologies based on modus operandi relationships, characteristics of the victims, and characteristics of perpetrators. The sample consisted of 448 homicide cases registered in the database of the Homicide Revision Project of the Office of Coordination and Studies of the Spanish Secretary of State and Security. Through multidimensional scaling and cluster analysis, three expressive homicide subtypes were identified (expressive-impulsive, expressive-distancing, and expressive-family), as well as two instrumental homicide subtypes (instrumental-opportunist and instrumental-gratification). The expressive homicide typologies accounted for almost 95% of all of the studied cases, and most of the homicides occurring in Spain were found to take place between individuals who know one another (friends, family members, intimate couples/ex-couples). The findings from this study suggest that the instrumental/expressive model may be a useful framework for understanding the psychological processes underlying homicides, based on the study of relationships between the crime and aggressor characteristics, which may be very helpful in the prioritization of suspect

Estrategias de posicionamiento de la empresa HecoMarket en la atención a sus clientes de las sucursales Estelí, 2016

El presente estudio tiene como objetivo analizar la implementación de acciones de marketing implementadas por HecoMarket en la ciudad de Estelí para el diseño de estrategias enfocadas en su posicionamiento. Se definieron como ejes teóricos, empresa, marketing, posicionamiento y competitividad. La investigación es de tipo cuantitativa, teniendo como universo de estudio los compradores que visitan las tiendas en las 24 horas, que en promedio son 1000 clientes diarios, entre las cuatro sucursales de HecoMarket ubicadas en la ciudad de Estelí. El tipo de muestreo es probabilístico. Se calculó la fórmula para población finita, obteniendo una muestra de 278 personas a encuestar. Se aplicaron como técnicas de recolección de datos la encuesta y la entrevista semi-estructurada e investigación documental

Propagation of Tau via extracellular vesicles

Extracellular vesicles (EVs), like exosomes, play a critical role in physiological processes, including synaptic transmission and nerve regeneration. However, exosomes in particular can also contribute to the development of neurodegenerative conditions such as Alzheimer’s disease (AD), Parkinson’s disease, and prion diseases. All of these disorders are characterized by protein aggregation and deposition in specific regions of the brain. Several lines of evidence indicate that protein in exosomes is released from affected neurons and propagated along neuroanatomically connected regions of the brain, thus spreading the neurodegenerative disease. Also, different cell types contribute to the progression of tauopathy, such as microglia. Several groups have reported tau release via exosomes by cultured neurons or cells overexpressing human tau. Although the exact mechanisms underlying the propagation of protein aggregates are not fully understood, recent findings have implicated EVs in this process. The AD brain has two hallmarks, namely the presence of amyloid-β-containing plaques and neurofibrillary tangles, the latter formed by hyperphosphorylated tau protein. Both amyloid peptide and tau protein are present in specific exosomes. This review summarizes recent advances in our understanding of exosomes in the pathology of AD, with a special focus on tau proteinThis study was funded by grants from Spanish Ministry of Science, Innovation and Universities (BFU2016- 77885-P), the Comunidad de Madrid, through EU structural funds (S2017/BMD-3700 NEUROMETAD-CM), CIBERNED (ISCIII), and the Fundacion Ramon Arece

Giving Voice to Women: Social Representations and Experiences of Breastfeeding

Breastfeeding is a central issue in research from a gender perspective. We consider breastfeeding as a biopsychosocial, diverse and plural process, which generates ambivalent experiences in mothers. Our research was aimed to increase the understanding of thoughts and experiences of mothers. Ten women, primiparous and non-primiparous mother, were interviewed at two moments in time. The results showed that the breastfeeding period was shorter than the time recommended by health organizations, the reasons to breastfeed were related to the well-being of their children and women´s social support came from their partners.Breastfeeding is a central issue in research from a gender perspective. We consider breastfeeding as a biopsychosocial, diverse and plural process, which generates ambivalent experiences in mothers. Our research was aimed to increase the understanding of thoughts and experiences of mothers. Ten women, primiparous and non-primiparous mother, were interviewed at two moments in time. The results showed that the breastfeeding period was shorter than the time recommended by health organizations, the reasons to breastfeed were related to the well-being of their children and women´s social support came from their partners

Volatiles from Subtropical Convolvulaceae That Interfere with Bacterial Cell-to-Cell Communication as Potential Antipathogenic Drugs

Increasing chronic bacterial infections create an urgent need for new antimicrobial agents or strategies for their control. Targetingvirulence is one of the alternative approaches to find new medicines to treat persistent infections due to bacteria with biofilmphenotypewhich are more resistant to antibiotics than their planktonic counterparts having an extreme capacity for evading the host defences. A bioguided study of sixteen extracts from flowers and leaves of four subtropical Convolvulaceae species provided evidence of the occurrence of antipathogenic natural products active against Gram positive and negative bacteria.Particularly, volatile metabolites from Merremia dissecta creeper, a food and medicinal plant, were able to interfere with the Pseudomonas aeruginosa quorum sensing system by a strong decrease of N-acyl homoserine lactone (AHL) biosynthesis (63?75%), which attenuated the virulence factor expression like biofilm (55%) and elastase activity (up to 27%), key factors thatenable the colonization and dissemination of the infection in the host. Control of the P. aeruginosa biofilm and the QS process by phytochemicals, such as (+) spathulenol, isolated from a bioactive extract of M. dissecta leaves would be a good strategy for the development of new and effective antipathogenic drugs.Fil: Luciardi, María Constanza. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Pérez Hernández, María Victoria. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Orgánica; ArgentinaFil: Muruaga, Nora. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Bardon, Alicia del Valle. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Orgánica; ArgentinaFil: Arena, Mario Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Orgánica; ArgentinaFil: Cartagena, Elena. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Orgánica; Argentin

Information and digital literacy challenges: a guide to bridge the gap between natives and digital immigrants

La alfabetización mediática y la alfabetización informacional se han convertido en un problema socioeconómico que excede el alcance de las bibliotecas. Las estructuras educativas formales, universidades y escuelas están seriamente involucradas en este tipo de alfabetización. Algunas instituciones privadas también están asumiendo parte de la alfabetización tecnológica de los trabajadores. Los organismos internacionales, OCDE, Unión Europea, Unesco y otros están redefiniendo las nuevas competencias básicas del siglo XXI. Las bibliotecas universitarias tienen experiencia en programas de alfabetización informacional. Falta definir el papel de las bibliotecas públicas como agentes formadores que ayuden a las distintas comunidades a superar la brecha entre nativos e inmigrantes digitales.Media and informational literacy has become a socioeconomic problem beyond the scope of the libraries. Formal education structures, universities and schools, are seriously involved in this kind of literacy. Some private institutions are also taking part in the Information Technology (IT) literacy of workers. International agencies, OECD, European Union, UNESCO and others are redefining the new basic skills for the 21st century. University libraries have experience in information literacy programs but it’s necessary to define the role of public libraries as forming agents that help different communities to bridge the gap between natives and digital immigrantsPublicad