844 research outputs found
Where are my followers? Understanding the Locality Effect in Twitter
Twitter is one of the most used applications in the current Internet with
more than 200M accounts created so far. As other large-scale systems Twitter
can obtain enefit by exploiting the Locality effect existing among its users.
In this paper we perform the first comprehensive study of the Locality effect
of Twitter. For this purpose we have collected the geographical location of
around 1M Twitter users and 16M of their followers. Our results demonstrate
that language and cultural characteristics determine the level of Locality
expected for different countries. Those countries with a different language
than English such as Brazil typically show a high intra-country Locality
whereas those others where English is official or co-official language suffer
from an external Locality effect. This is, their users have a larger number of
followers in US than within their same country. This is produced by two
reasons: first, US is the dominant country in Twitter counting with around half
of the users, and second, these countries share a common language and cultural
characteristics with US
Control interno en las entidades del estado colombiano
"El control interno constituye una serie de acciones que se interrelacionan y se extienden a todas las actividades de una organización, éstas son inherentes a la gestión del negocio (actividades de una entidad). El control interno es parte y está integrado a los procesos de gestión básicos: planificación, ejecución y supervisión, y se encuentra entrelazado con las actividades operativas de una organización. Los controles internos son más efectivos cuando forman parte de la esencia de una organización, cuando son ""incorporados"" e ""internalizados"" y no ""añadidos""."Pregrad
Is Content Publishing in BitTorrent Altruistic or Profit-Driven
BitTorrent is the most popular P2P content delivery application where
individual users share various type of content with tens of thousands of other
users. The growing popularity of BitTorrent is primarily due to the
availability of valuable content without any cost for the consumers. However,
apart from required resources, publishing (sharing) valuable (and often
copyrighted) content has serious legal implications for user who publish the
material (or publishers). This raises a question that whether (at least major)
content publishers behave in an altruistic fashion or have other incentives
such as financial. In this study, we identify the content publishers of more
than 55k torrents in 2 major BitTorrent portals and examine their behavior. We
demonstrate that a small fraction of publishers are responsible for 66% of
published content and 75% of the downloads. Our investigations reveal that
these major publishers respond to two different profiles. On one hand,
antipiracy agencies and malicious publishers publish a large amount of fake
files to protect copyrighted content and spread malware respectively. On the
other hand, content publishing in BitTorrent is largely driven by companies
with financial incentive. Therefore, if these companies lose their interest or
are unable to publish content, BitTorrent traffic/portals may disappear or at
least their associated traffic will significantly reduce
Active Control Stabilization of High Power Rocket
High power rockets could become dynamically unstable due to outside disturbances after takeoff. The instability is augmented when the rocket is slow off the launch rail, which happens when the thrust-to-weight ratio is less than 5:1. Due to these reasons, the objective of this project was to design and build an active control system that will make sure the rocket follows a straight path all the way to apogee. This will be done through a model-based design approach, in which a 6DOF mathematical model of the flight dynamics will be created
Melanoma expression analysis with Big Data technologies
Melanoma is a highly immunogenic tumor. Therefore, in recent years physicians have incorporated drugs that alter the immune system into their therapeutic arsenal against this disease, revolutionizing in the treatment of patients in an advanced stage of the disease. This has led us to explore and deepen our knowledge of the immunology surrounding melanoma, in order to optimize its approach. At present, immunotherapy for metastatic melanoma is based on stimulating an individual’s own immune system through the use of specific monoclonal antibodies. The use of immunotherapy has meant that many of patients with melanoma have survived and therefore it constitutes a present and future treatment in this field. At the same time, drugs have been developed targeting specific mutations, specifically BRAF, resulting in large responses in tumor regression (set up in this clinical study to 18 months), as well as a higher percentage of long-term survivors. The analysis of the gene expression changes and their correlation with clinical changes can be developed using the tools provided by those companies which currently provide gene expression platforms. The gene expression platform used in this clinical study is NanoString, which provides nCounter. However, nCounter has some limitations as the type of analysis is restricted to a predefined set, and the introduction of clinical features is a complex task. This paper presents an approach to collect the clinical information using a structured database and a Web user interface to introduce this information, including the results of the gene expression measurements, to go a step further than the nCounter tool. As part of this work, we present an initial analysis of changes in the gene expression of a set of patients before and after targeted therapy. This analysis has been carried out using Big Data technologies (Apache Spark) with the final goal being to scale up to large numbers of patients, even though this initial study has a limited number of enrolled patients (12 in the first analysis). This is not a Big Data problem, but the underlaying study aims at targeting 20 patients per year just in Málaga, and this could be extended to be used to analyze the 3.600 patients diagnosed with melanoma per year.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This work was funded in part by Grants TIN2014-58304-R (Ministerio de Ciencia e Innovación) and P11-TIC-7529 and P12-TIC-1519 (Plan Andaluz de Investigación, Desarrollo e Innovación). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Optimización de la producción de energía de una celda tipo PEM.
El electrolizador utilizado en la tesis anterior desarrollada por Piedra y Noboa no suministraba el caudal de Hidrógeno necesario para el correcto funcionamiento de la celda tipo PEM. Se realizó un diseño que permita mejorar el caudal, mantener una presión constante para poder mejorar el rendimiento de la celda y mejorar la generación eléctrica de la misma.
Este proyecto describe el paso a paso de las pruebas realizadas, desde la obtención del permiso de compra del hidróxido de potasio en el Setep ya que al ser una sustancia sujeta a fiscalización, este compuesto no se lo puede conseguir sin dicho permiso, también incluye el diseño de lo necesario para el almacenamiento de Hidrógeno producido por el electrolizador modelo AU43, consumos energéticos del nuevo electrolizador, generación de energía utilizado la celda de combustible tipo PEM de 100W, análisis y cuadros comparativos de las datos obtenidos con los que obtuvieron los investigadores anteriores Piedra y Noboa y como se logró mejorar el del flujo de Hidrógeno en un 76.92%.The electrolyser used in the previous thesis developed by Piedra and Noboa did not supply the flow of Hydrogen necessary for the correct functioning of the PEM type cell. A design was made to improve the flow, maintain a constant pressure to improve the cell's performance and improve its power generation.
This project describes the step by step of the tests carried out, since obtaining the purchase permit for potassium hydroxide in the Setep since being a substance subject to control, this compound cannot be obtained without such permission, it also includes the design of what is necessary for the storage of hydrogen produced by the AU43 model electrolyzer, energy consumption of the new electrolyser, power generation using a 100W PEM type fuel cell, analysis and comparative tables of the data obtained with those obtained by previous researchers Piedra and Noboa and how the Hydrogen flow was improved by 76.92%
Estudio de las alteraciones genéticas asociadas con la resistencia al tratamiento neoadjuvante de deprivación estrogénica en cáncer de mama
With current standard of care adjuvant therapy, approximately 25-30% of women with high risk early stage HR+/HER2- breast cancer experience relapse. The preoperative platform offers an opportunity to interrogate mechanisms of drug resistance that, in turn, could inform the choice of adjuvant therapy. We report herein a study where we performed targeted DNA sequencing and whole transcriptome analysis on whole tumor sections from a cohort of 68 operable ER+ breast cancers treated with the aromatase inhibitor letrozole for a median of 7.2 months before surgery, and a with a median follow up of 5 years.
We found that resistant tumors were enriched in clinically actionable mutation and showed an enrichment in expression of genes involved in proliferation. Resistant tumors show a high degree of heterogeneity among them upregulating a variety of transcriptional programs. A common feature among resistant tumors was a co-expression of several genes dependent on the E2F4 transcription factor. We defined an E2F4 activation signature that define ER+ breast cancer with poor prognostic features and is sensitive to treatment with CDK4/6 inhibitors. This signature is of potential use for the identification of patients with ER+ breast cancer candidates for adjuvant therapy with CDK4/6 inhibitors in combination with antiestrogens. Our study also identifies a novel gene, PRR11 (Proline rich 11), as a putative driver of endocrine resistance in ER+ breast cancers and that merits further investigation to understand its mechanisms of action.With current standard of care adjuvant therapy, approximately 25-30% of women with high risk early stage HR+/HER2- breast cancer experience relapse. The preoperative platform offers an opportunity to interrogate mechanisms of drug resistance that, in turn, could inform the choice of adjuvant therapy. We report herein a study where we performed targeted DNA sequencing and whole transcriptome analysis on whole tumor sections from a cohort of 68 operable ER+ breast cancers treated with the aromatase inhibitor letrozole for a median of 7.2 months before surgery, and a with a median follow up of 5 years.
We found that resistant tumors were enriched in clinically actionable mutation and showed an enrichment in expression of genes involved in proliferation. Resistant tumors show a high degree of heterogeneity among them upregulating a variety of transcriptional programs. A common feature among resistant tumors was a co-expression of several genes dependent on the E2F4 transcription factor. We defined an E2F4 activation signature that define ER+ breast cancer with poor prognostic features and is sensitive to treatment with CDK4/6 inhibitors. This signature is of potential use for the identification of patients with ER+ breast cancer candidates for adjuvant therapy with CDK4/6 inhibitors in combination with antiestrogens. Our study also identifies a novel gene, PRR11 (Proline rich 11), as a putative driver of endocrine resistance in ER+ breast cancers and that merits further investigation to understand its mechanisms of action
ModeS TimeBank: un corpus TimeBank del español moderno
Con el objetivo de representar y analizar grandes cantidades de fuentes históricas textuales en un Sistema de Información Geográfica (SIG), se ha creado ModeS TimeBank. ModeS TimeBank es un corpus del español moderno (s. XVIII) anotado con información semántica temporal, eventiva y espacial, donde destaca el uso de los lenguajes de marcado TimeML y SpatialML. El corpus es además relevante no sólo por su datación e idioma sino por su dominio ya que está enmarcado en la temática de las redes de cooperación. El presente artículo pretende describir cómo se ha creado el corpus y qué criterios se han tenido en cuenta en su creación, además de señalar el alcance y las aplicaciones de ModeS TimeBan
Desarrollo e implementación de un portal web de alimentos nutricionales www.cuidaloquecomes.com
Nuestro país, siendo un estado en vías de desarrollo, a logrado la disminución de casos de enfermedades transmisibles (difteria, sarampión, tétano, etc.); sin embargo los cambios en los hábitos alimenticios poco saludable (alta en grasa, azúcar y sal, baja en frutas, granos y vegetales) y la falta de actividad física han provocado un aumento rápido en las denominadas Enfermedades No Transmisibles (ENTs) en poblaciones cada vez más jóvenes. En el país las ENTs derivadas de los malos hábitos alimenticios son: diabetes mellitus, enfermedades cardiovasculares, hipertensión arterial, obesidad, tumores malignos e insuficiencia renal, estas molestias asolan a nuestro país desde hace dos décadas y actualmente se han convertido en las primeras causas de muerte y discapacidad. Ante esta premisa y aprovechando el impacto del Internet en la sociedad actual surge una fusión de ideas donde nace Cuidaloquecomes, un portal web especializado en alimentación saludable que provee servicio de catering a domicilio y tienda online de productos de primera necesidad, además de otros beneficios como: consultas con especialistas, foros e información actualizada. El objetivo principal del proyecto es, ayudar a personas con enfermedades no transmisibles a llevar un régimen de alimentación sana, contando con una asistencia segura, oportuna, higiénica y saludable para prevenir o tratar adecuadamente sus problemas de salud
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