83 research outputs found
Strategies of the Spanish press in the face of the Twitter algorithm change. Analysis of tweets published between 2018-2020
Twitter recently celebrated its 15th anniversary. During this period, the platform has gone through several phases, culminating in a record number of subscribers and profits in 2021. Twitter is a household name all over the world and people know what it can or cannot provide, independent of the future growth that it may experience with new investments and updates. This article aims to verify two interrelated hypotheses, namely: the Spanish press already knows how to optimise the social network Twitter, as three decades have elapsed since its launch; and, secondly, the algorithm modification implemented by Twitter in 2018 has triggered a change in the positioning of the headers studied in this social network. In order to demonstrate both, the object of analysis will be conducted by a mixed approach through quantitative statistical processes (which will study the number of impacts and retweets and likes obtained), and inductive qualitative methods such as semi-structured interviews. This multidisciplinary approach will provide a more complete and in-depth analysis of the phenomenon. The research focuses on the period between 2018 and 2020, and addresses the participation on Twitter of the four main traditional newspapers (El País, La Vanguardia, ABC and El Mundo) as well as four native digital newspapers (20 Minutos, El Español, elDiario.es and El Huffpost). The analysis comprises more than 1.5 million tweets among the eight chosen newspapers.Twitter acaba de celebrar su decimoquinto aniversario. Durante este periodo, la plataforma ha pasado varias fases que han culminado con un récord de suscriptores y beneficios en 2021. El mundo conoce Twitter y sabe qué es lo que puede o no proporcionar, aparte de las posibilidades de crecimiento que pueda experimentar en caso de potenciales inversiones. En el presente artículo se pretende comprobar dos hipótesis interrelacionadas, a saber: la prensa española en castellano ya sabe cómo optimizar la red social Twitter, por haber transcurrido tres lustros desde su puesta en marcha; y, en segundo lugar, el cambio de algoritmo implementado por Twitter en 2018 que ha desencadenado un cambio de posicionamiento de las cabeceras estudiadas en esta red social. Con el propósito de demostrar ambas, se abordará el objeto de análisis desde un enfoque mixto a través de procesos cuantitativos estadísticos (que estudiarán el número de impactos y de retuits y likes obtenidos), y métodos cualitativos inductivos como entrevistas semiestructuradas a los responsables de redes de los medios involucrados. Esta aproximación mixta proporcionará un análisis más completo y profundo sobre el fenómeno. La investigación se centra en el período comprendido entre 2018 y 2020, y aborda la participación en Twitter de cuatro periódicos tradicionales (El País, La Vanguardia, ABC y El Mundo), así como de cuatro periódicos nativos digitales (20 Minutos, El Español, elDiario.es y El Huffpost). El análisis comprende más de 1,5 millones de tuits entre los ocho periódicos elegidos
Influence of metal organic chemical vapour deposition growth conditions on vibrational and luminescent properties of ZnO nanorods
Producción CientíficaA detailed optical characterization by means of micro Raman and cathodoluminescence spectroscopy of catalyst-free ZnO nanorods grown by atmospheric-metal organic chemical vapour deposition has been carried out. This characterization has allowed correlating the growth conditions, in particular the precursors partial-pressures and growth time, with the optical properties of nanorods. It has been shown that a high Zn supersaturation can favor the incorporation of nonradiative recombination centers, which can tentatively be associated with ZnI-related defects. Characterization of individual nanorods has evidenced that ZnI-related defects have a tendency to accumulate in the tip part of the nanorods, which present dark cathodoluminescence contrast with respect to the nanorods bottom. The effect of a ZnO buffer layer on the properties of the nanorods has been also investigated, showing that the buffer layer improves the luminescence efficiency of the ZnO nanorods, revealing a significant reduction of the concentration of nonradiative recombination centers.Ministerio de Ciencia e Innovación (Projects MAT2007-66129, MAT-2010-20441-C02, MAT-2010-16116, and TEC2011-28076-C02-02)Generalitat Valenciana (Prometeo/2011-035 and ISIC/2012/008, Institute of Nanotechnologies for Clean Energies
Residual Strain and Electrical Activity of Defects in Multicrystalline Silicon Solar Cells
Producción CientíficaThe growth process by casting methods of multi-crystalline Si results in a crystalline material with, among other defects, a high density of dislocations and grain boundaries. Impurity incorporation and their gathering around grain boundaries and dislocations seem to be the main factor determining the electrical activity of those defects, which limit the minority carrier lifetime. In this work, we analyze multi-crystalline Si samples by combining etching processes to reveal the defects, Raman spectroscopy for strain measurements, and light beam induced current measurements for the localization of electrically active defects. In particular, we have explored the etching routes capable to reveal the main defects (grain boundaries and dislocation lines), while their electrical activity is studied by the light beam induced current technique. We further analyze the strain levels around these defects by Raman micro-spectroscopy, aiming to obtain a more general picture of the correlation between residual stress and electrical activity of the extended defects. The higher stress levels are observed around intra-grain defects associated with dislocation lines, rather than around the grain boundaries. On the other hand, the intra-grain defects are also observed to give dark light beam induced current contrast associated with a higher electrical activity of these defects as compared to the grain boundariesJunta de Castilla y León (programa de apoyo a proyectos de investigación – Ref. A166A11-2)Ministerio de Ciencia e innovación (IPT-420000-2010- -022 INNPACTO program
Development of a compact and low-cost weather station for renewable energy applications
This paper describes the development of a weather station integrating several sensors which allows the measurement and data storage of the following environmental parameters: solar irradiance, temperature, humidity, wind speed, and wind direction. The collected data is later transferred to a mobile device, where it is stored in a database and processed in order to be visualized and analyzed by the user. For such purpose, a dedicated mobile app was developed and presented along the paper. The weather station also integrates small solar photovoltaic modules of three different technologies: polycrystalline, monocrystalline and amorphous silicon. Based on that, the weather station also collects information that may be employed to help the user in determining the most suitable solar photovoltaic technology for installation in a particular location. The developed system uses a Bluetooth Low Energy (BLE) wireless network to transfer the data to the mobile device when the user approaches the weather station. The system operation was validated through experimental tests that encompass all the main developed features, from the data acquisition in the weather station, to the visualization in the mobile device.- (undefined
Artrodesis subtalar primaria como tratamiento de fracturas conminutas de calcáneo Sanders tipo IV
Las fracturas conminutas Sanders IV de calcáneo dan lugar, en la mayoría de los casos, a una artrosis subtalar postraumática dolorosa e incapacitante, que en muchas ocasiones, requiere una artrodesis subtalar secundaria. Esta artrodesis puede ser técnicamente compleja, ya que no se trata de una fijación in situ, sino que requiere la realización de osteotomías de corrección a nivel del cuerpo del calcáneo en la misma cirugía.Material y métodos. Presentamos 4 pacientes con fracturas conminutas de calcáneo Sanders tipo IV que fueron tratadas mediante una artrodesis subtalar primaria con reconstrucción concomitante del cuerpo del calcáneo. El seguimiento medio fue de 15 meses. Resultados. Obtuvimos la consolidación ósea, tanto de la artrodesis como de la fractura, alrededor de los 4 meses, sin existir signos de artrosis en otras articulaciones. No hubo ninguna complicación de herida quirúrgica, ni aparecieron otras complicaciones típicas de estas lesiones, como impingement de peroneos, problemas con el calzado o bloqueo o degeneración de la articulación tibio talar durante el seguimiento. La puntuación AOFAS media a los 12 meses fue de 78. Conclusiones. La artrodesis subtalar primaria con la corrección inicial de las deformidades asociadas en el cuerpo del calcáneo (acortamiento, ensanchamiento y varo) evita complicaciones posteriores y obtiene buenos resultados
Mobile ad hoc network testbed using mobile robot technology
MANET (Mobile Ad Hoc Network) researchers have shown increased interest in using mobile robot technology for their testbed platforms. Thus, the main motivation of this paper is to review various robot-based MANET testbeds that have been developed in previously reported research. Additionally, suggestions to heighten mobility mechanisms by using mobile robots to be more practical, easy and inexpensive are also included in this paper, as we unveils ToMRobot, a low-cost MANET robot created from an ordinary remote control car that is capable of performing a real system MANET testbed with the addition of only a few low-cost electronic components. Despite greatly reduced costs, the ToMRobot does not sacrifice any of the necessary MANET basic structures and will still be easily customizable and upgradeable through the use of open hardware technology like Cubieboard2 and Arduino, as its robot controller. This paper will also include guidelines to enable technically limited MANET researchers to design and develop the ToMRobot. It is hoped that this paper achieves its two pronged objectives namely (i) to facilitate other MANET researchers by providing them with a source of reference that eases their decision making for selecting the best and most suitable MANET mobile robots for real mobility in their MANET testbeds (ii) to provide MANET researchers with a prospect of building their own MANET robots that can be applied in their own MANET testbed in the future
PSORIASIS IS ASSOCIATED WITH ELEVATED GUT IL-1Α AND INTESTINAL MICROBIOME ALTERATIONS
Psoriasis is a chronic inflammatory condition that predominantly affects the skin and is associated with extracutaneous disorders, such as inflammatory bowel disease and arthritis. Changes in gut immunology and microbiota are important drivers of proinflammatory disorders and could play a role in the pathogenesis of psoriasis. Therefore, we explored whether psoriasis in a Central Asian cohort is associated with alterations in select immunological markers and/or microbiota of the gut
The carcinogenic potential of tacrolimus ointment beyond immune suppression: a hypothesis creating case report
BACKGROUND: Since tacrolimus ointment was approved by the U.S. Food and Drug Administration (FDA) as a promising treatment for atopic dermatitis, it has been approved in more than 30 additional countries, including numerous European Union member nations. Moreover, in the current clinical routine the use of this drug is no longer restricted to the approved indication, but has been extended to a wide variety of inflammatory skin diseases including some with the potential of malignant transformation. So far, the side-effects reported from the topical use of tacrolimus have been relatively minor (e.g. burning, pruritus, erythema). Recently, however, the FDA reviewed the safety of topical tacrolimus, which resulted in a warning that the use of calcineurin inhibitors may be associated with an increased risk of cancer. CASE PRESENTATION: Oral lichen planus (OLP) was diagnosed in a 56-year-old women in February 1999. After several ineffective local and systemic therapeutic measures an off-label treatment of this recalcitrant condition using Tacrolimus 0.1% ointment was initiated in May 2002. After a few weeks of treatment most of the lesions ameliorated, with the exception of the plaques on the sides of the tongue. Nevertheless, the patient became free of symptoms which, however, reoccurred once tacrolimus was weaned, as a consequence treatment was maintained. In April 2005, the plaques on the left side of the tongue appeared increasingly compact and a biopsy specimen confirmed the suspected diagnosis of an oral squamous cell carcinoma. CONCLUSION: The suspected causal relationship between topical use of tacrolimus and the development of a squamous cell carcinoma prompted us to test the notion that the carcinogenicity of tacrolimus may go beyond mere immune suppression. To this end, tacrolimus has been shown to have an impact on cancer signalling pathways such as the MAPK and the p53 pathway. In the given case, we were able to demonstrate that these pathways had also been altered subsequent to tacrolimus therapy
Height and timing of growth spurt during puberty in young people living with vertically acquired HIV in Europe and Thailand.
OBJECTIVE: The aim of this study was to describe growth during puberty in young people with vertically acquired HIV. DESIGN: Pooled data from 12 paediatric HIV cohorts in Europe and Thailand. METHODS: One thousand and ninety-four children initiating a nonnucleoside reverse transcriptase inhibitor or boosted protease inhibitor based regimen aged 1-10 years were included. Super Imposition by Translation And Rotation (SITAR) models described growth from age 8 years using three parameters (average height, timing and shape of the growth spurt), dependent on age and height-for-age z-score (HAZ) (WHO references) at antiretroviral therapy (ART) initiation. Multivariate regression explored characteristics associated with these three parameters. RESULTS: At ART initiation, median age and HAZ was 6.4 [interquartile range (IQR): 2.8, 9.0] years and -1.2 (IQR: -2.3 to -0.2), respectively. Median follow-up was 9.1 (IQR: 6.9, 11.4) years. In girls, older age and lower HAZ at ART initiation were independently associated with a growth spurt which occurred 0.41 (95% confidence interval 0.20-0.62) years later in children starting ART age 6 to 10 years compared with 1 to 2 years and 1.50 (1.21-1.78) years later in those starting with HAZ less than -3 compared with HAZ at least -1. Later growth spurts in girls resulted in continued height growth into later adolescence. In boys starting ART with HAZ less than -1, growth spurts were later in children starting ART in the oldest age group, but for HAZ at least -1, there was no association with age. Girls and boys who initiated ART with HAZ at least -1 maintained a similar height to the WHO reference mean. CONCLUSION: Stunting at ART initiation was associated with later growth spurts in girls. Children with HAZ at least -1 at ART initiation grew in height at the level expected in HIV negative children of a comparable age
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