20 research outputs found

    Interest communities and flow roles in directed networks: the Twitter network of the UK riots

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    Directionality is a crucial ingredient in many complex networks in which information, energy or influence are transmitted. In such directed networks, analysing flows (and not only the strength of connections) is crucial to reveal important features of the network that might go undetected if the orientation of connections is ignored. We showcase here a flow-based approach for community detection in networks through the study of the network of the most influential Twitter users during the 2011 riots in England. Firstly, we use directed Markov Stability to extract descriptions of the network at different levels of coarseness in terms of interest communities, i.e., groups of nodes within which flows of information are contained and reinforced. Such interest communities reveal user groupings according to location, profession, employer, and topic. The study of flows also allows us to generate an interest distance, which affords a personalised view of the attention in the network as viewed from the vantage point of any given user. Secondly, we analyse the profiles of incoming and outgoing long-range flows with a combined approach of role-based similarity and the novel relaxed minimum spanning tree algorithm to reveal that the users in the network can be classified into five roles. These flow roles go beyond the standard leader/follower dichotomy and differ from classifications based on regular/structural equivalence. We then show that the interest communities fall into distinct informational organigrams characterised by a different mix of user roles reflecting the quality of dialogue within them. Our generic framework can be used to provide insight into how flows are generated, distributed, preserved and consumed in directed networks.Comment: 32 pages, 14 figures. Supplementary Spreadsheet available from: http://www2.imperial.ac.uk/~mbegueri/Docs/riotsCommunities.zip or http://rsif.royalsocietypublishing.org/content/11/101/20140940/suppl/DC

    The 'who' and 'what' of #diabetes on Twitter

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    Social media are being increasingly used for health promotion, yet the landscape of users, messages and interactions in such fora is poorly understood. Studies of social media and diabetes have focused mostly on patients, or public agencies addressing it, but have not looked broadly at all the participants or the diversity of content they contribute. We study Twitter conversations about diabetes through the systematic analysis of 2.5 million tweets collected over 8 months and the interactions between their authors. We address three questions: (1) what themes arise in these tweets?, (2) who are the most influential users?, (3) which type of users contribute to which themes? We answer these questions using a mixed-methods approach, integrating techniques from anthropology, network science and information retrieval such as thematic coding, temporal network analysis, and community and topic detection. Diabetes-related tweets fall within broad thematic groups: health information, news, social interaction, and commercial. At the same time, humorous messages and references to popular culture appear consistently, more than any other type of tweet. We classify authors according to their temporal 'hub' and 'authority' scores. Whereas the hub landscape is diffuse and fluid over time, top authorities are highly persistent across time and comprise bloggers, advocacy groups and NGOs related to diabetes, as well as for-profit entities without specific diabetes expertise. Top authorities fall into seven interest communities as derived from their Twitter follower network. Our findings have implications for public health professionals and policy makers who seek to use social media as an engagement tool and to inform policy design.Comment: 25 pages, 11 figures, 7 tables. Supplemental spreadsheet available from http://journals.sagepub.com/doi/suppl/10.1177/2055207616688841, Digital Health, Vol 3, 201

    O conceito de willingness to pay em questão

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    São revisadas as limitações do uso do conceito de willingness to pay (disposição a pagar) nas avaliações econômicas que se realizam no campo da saúde. Há na literatura econômica muitos investigadores que assinalam os múltiplos problemas metodológicos inerentes às estimações de willingness to pay. Por outro lado, o debate teórico-conceitual acerca da agregação das preferências individuais dentro de uma demanda agregada não está totalmente resolvido. Contudo, durante os últimos 20 anos, a estimação da disposição a pagar calculada pelos estudos tem aumentado de forma significativa, sendo em muitos casos um dos principais fatores de tomada de decisão em políticas de saúde. São apresentadas algumas das limitações desta técnica, assim como o possível efeito de distorção que poderia ter sobre as avaliações econômicas em saúde.The adequacy of the concept of willingness to pay within health economics evaluations is reviewed. A considerable number of researchers in the literature have pointed out multiple methodological issues involving willingness-to-pay estimates. On the other hand, the theoretical discussion about the aggregation of individual preferences within an aggregate demand remains open. However, over the last 20 years, willingness-to-pay estimates alongside health economics research significantly increased and in many cases they are one of the key factors for decision making on issues of health policies. The article describes some limitations of this approach as well as the potential distorting effect that it might have on health economics evaluations.La idoneidad del concepto de willingness to pay (disponibilidad a pagar) es revisado en las evaluaciones económicas que se realizan en el campo de la salud. Por un lado, existe dentro de la literatura económica un número importante de investigadores que señalan los múltiples problemas metodológicos que entrañan las estimaciones de willingness to pay. Por otro lado, aún el debate teórico-conceptual acerca de la agregación de las preferencias individuales dentro de una demanda agregada no ésta del todo resuelto. Sin embargo, durante los últimos 20 años la estimación de la disponibilidad a pagar dentro de las investigaciones económicas ha aumentado de forma significativa, siendo en muchos casos uno de los principales factores de la toma de decisión en políticas de salud. Plantease alguna de las limitaciones de esta técnica, así como el posible efecto distorsionador que podría tener sobre las evaluaciones económicas que se realizan en el área de la economía de la salud

    Ciencia Odontológica 2.0

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    Libro que muestra avances de la Investigación Odontológica en MéxicoEs para los integrantes de la Red de Investigación en Estomatología (RIE) una enorme alegría presentar el segundo de una serie de 6 libros sobre casos clínicos, revisiones de la literatura e investigaciones. La RIE está integrada por cuerpos académicos de la UAEH, UAEM, UAC y UdeG

    CARB-ES-19 Multicenter Study of Carbapenemase-Producing Klebsiella pneumoniae and Escherichia coli From All Spanish Provinces Reveals Interregional Spread of High-Risk Clones Such as ST307/OXA-48 and ST512/KPC-3

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    ObjectivesCARB-ES-19 is a comprehensive, multicenter, nationwide study integrating whole-genome sequencing (WGS) in the surveillance of carbapenemase-producing K. pneumoniae (CP-Kpn) and E. coli (CP-Eco) to determine their incidence, geographical distribution, phylogeny, and resistance mechanisms in Spain.MethodsIn total, 71 hospitals, representing all 50 Spanish provinces, collected the first 10 isolates per hospital (February to May 2019); CPE isolates were first identified according to EUCAST (meropenem MIC > 0.12 mg/L with immunochromatography, colorimetric tests, carbapenem inactivation, or carbapenem hydrolysis with MALDI-TOF). Prevalence and incidence were calculated according to population denominators. Antibiotic susceptibility testing was performed using the microdilution method (EUCAST). All 403 isolates collected were sequenced for high-resolution single-nucleotide polymorphism (SNP) typing, core genome multilocus sequence typing (cgMLST), and resistome analysis.ResultsIn total, 377 (93.5%) CP-Kpn and 26 (6.5%) CP-Eco isolates were collected from 62 (87.3%) hospitals in 46 (92%) provinces. CP-Kpn was more prevalent in the blood (5.8%, 50/853) than in the urine (1.4%, 201/14,464). The cumulative incidence for both CP-Kpn and CP-Eco was 0.05 per 100 admitted patients. The main carbapenemase genes identified in CP-Kpn were blaOXA–48 (263/377), blaKPC–3 (62/377), blaVIM–1 (28/377), and blaNDM–1 (12/377). All isolates were susceptible to at least two antibiotics. Interregional dissemination of eight high-risk CP-Kpn clones was detected, mainly ST307/OXA-48 (16.4%), ST11/OXA-48 (16.4%), and ST512-ST258/KPC (13.8%). ST512/KPC and ST15/OXA-48 were the most frequent bacteremia-causative clones. The average number of acquired resistance genes was higher in CP-Kpn (7.9) than in CP-Eco (5.5).ConclusionThis study serves as a first step toward WGS integration in the surveillance of carbapenemase-producing Enterobacterales in Spain. We detected important epidemiological changes, including increased CP-Kpn and CP-Eco prevalence and incidence compared to previous studies, wide interregional dissemination, and increased dissemination of high-risk clones, such as ST307/OXA-48 and ST512/KPC-3

    Programa de prácticas de zootecnia bovinos productores de carne (2004)

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    Lograr que el alumno identifique las características y cualidades de las razas productoras de carne que sea posible mostrarles en las unidades de producción que se visiten, haciendo énfasis en la importancia que tienen los bovinos de carne como acceso para el humano a la fuente de proteína de origen animal, así como la problemática para producirla para consumo humano. Así mismo observara, reconocerá y valorara el sistema o sistemas de producción

    El concepto de willingness-to-pay en tela de juicio O conceito de willingness to pay em questão The willingness-to-pay concept in question

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    La idoneidad del concepto de willingness to pay (disponibilidad a pagar) es revisado en las evaluaciones económicas que se realizan en el campo de la salud. Por un lado, existe dentro de la literatura económica un número importante de investigadores que señalan los múltiples problemas metodológicos que entrañan las estimaciones de willingness to pay. Por otro lado, aún el debate teórico-conceptual acerca de la agregación de las preferencias individuales dentro de una demanda agregada no ésta del todo resuelto. Sin embargo, durante los últimos 20 años la estimación de la disponibilidad a pagar dentro de las investigaciones económicas ha aumentado de forma significativa, siendo en muchos casos uno de los principales factores de la toma de decisión en políticas de salud. Plantease alguna de las limitaciones de esta técnica, así como el posible efecto distorsionador que podría tener sobre las evaluaciones económicas que se realizan en el área de la economía de la salud.São revisadas as limitações do uso do conceito de willingness to pay (disposição a pagar) nas avaliações econômicas que se realizam no campo da saúde. Há na literatura econômica muitos investigadores que assinalam os múltiplos problemas metodológicos inerentes às estimações de willingness to pay. Por outro lado, o debate teórico-conceitual acerca da agregação das preferências individuais dentro de uma demanda agregada não está totalmente resolvido. Contudo, durante os últimos 20 anos, a estimação da disposição a pagar calculada pelos estudos tem aumentado de forma significativa, sendo em muitos casos um dos principais fatores de tomada de decisão em políticas de saúde. São apresentadas algumas das limitações desta técnica, assim como o possível efeito de distorção que poderia ter sobre as avaliações econômicas em saúde.The adequacy of the concept of willingness to pay within health economics evaluations is reviewed. A considerable number of researchers in the literature have pointed out multiple methodological issues involving willingness-to-pay estimates. On the other hand, the theoretical discussion about the aggregation of individual preferences within an aggregate demand remains open. However, over the last 20 years, willingness-to-pay estimates alongside health economics research significantly increased and in many cases they are one of the key factors for decision making on issues of health policies. The article describes some limitations of this approach as well as the potential distorting effect that it might have on health economics evaluations

    Integrating sentiment and social structure to determine preference alignments: the Irish marriage referendum

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    We examine the relationship between social structure and sentiment through the analysis of a large collection of tweets about the Irish Marriage Referendum of 2015. We obtain the sentiment of every tweet with the hashtags #marref and #marriageref that was posted in the days leading to the referendum, and construct networks to aggregate sentiment and use it to study the interactions among users. Our analysis shows that the sentiment of outgoing mention tweets is correlated with the sentiment of incoming mentions, and there are significantly more connections between users with similar sentiment scores than among users with opposite scores in the mention and follower networks. We combine the community structure of the follower and mention networks with the activity level of the users and sentiment scores to find groups that support voting ‘yes’ or ‘no’ in the referendum. There were numerous conversations between users on opposing sides of the debate in the absence of follower connections, which suggests that there were efforts by some users to establish dialogue and debate across ideological divisions. Our analysis shows that social structure can be integrated successfully with sentiment to analyse and understand the disposition of social media users around controversial or polarizing issues. These results have potential applications in the integration of data and metadata to study opinion dynamics, public opinion modelling and polling

    Economic evaluation of the use of exogenous pulmonary surfactants in preterm newborns in a Mexican population Evaluación económica de la utilización de surfactantes pulmonares exógenos en recién nacidos pretérmino en población mexicana

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    OBJECTIVE: To estimate the cost-effectiveness ratio of surfactant rescue treatment of premature infants with respiratory distress syndrome (RDS) who are covered by the Medical Insurance for a New Generation. MATERIALS AND METHODS: A cost-effectiveness evaluation was conducted from the third-payer perspective. Comparisons were made between the use of bovine surfactant (BS) therapy and without BS therapy. A decision tree model with a lifetime horizon was used where the measurements of effectiveness were life years gained (LYG) and quality-adjusted life years (QALYs). A 5% discount rate was considered for costs and health outcomes. All costs are expressed in Mexican pesos 2009. RESULTS: Incremental cost-effectiveness ratios (ICER) were MXN136670perLYGandMXN136670 per LYG and MXN125250 per QALY. CONCLUSION: Surfactant therapy was confirmed as a cost-effective strategy in accordance with World Health Organization criteria of three per capita gross domestic product (GDP) per QALY in premature infants with RDS in Mexico.OBJETIVO: Estimar la razón de costo efectividad incremental del tratamiento de surfactante de rescate en pacientes pretérmino con Síndrome de Dificultad Respiratoria (SDR) cubiertos por el Seguro Médico para una Nueva Generación. MATERIAL Y MÉTODOS: Evaluación de costo-efectividad desde la perspectiva del tercer pagador. Los comparadores fueron la terapia de surfactante bovino y la alternativa de no emplear ésta. Se utilizó un árbol de decisión que consideró la esperanza de vida como horizonte temporal y las medidas de efectividad fueron los años de vida ganados (AVG) y los años de vida ajustados por calidad de vida ( AVAC).Resultados en pesos mexicanos del 2009. RESULTADOS: Las RCEI por AVG y AVAC fueron de MXN136670yMXN136670 y MXN125250. CONCLUSIÓN: La razón de costo por AVG y AVAC para la terapia de surfactantes en pacientes prematuros con SDR en México fue menor a tres veces el PIB per cápita, por lo que es una estrategia costo-efectiva según los criterios de la OMS
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