Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Inf Syst Front ; 25(2): 473-492, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36118953

RESUMO

The spreading of disinformation in social media threatens cybersecurity and undermines market efficiency. Detecting disinformation is challenging due to large volumes of social media content and a rapidly changing environment. This research developed and validated a theory-based, novel deep-learning approach (called TRNN) to disinformation detection. Grounded in social and psychological theories, TRNN uses deep-learning and data-centric augmentation to enhance disinformation detection in financial social media. Temporal and contextual information is encoded as specific knowledge about human-validated disinformation, which was identified from our unique collection of 745,139 financial social media messages about four U.S. high-tech company stocks and their fine-grained trading data. TRNN uses multiple series of long short-term memory (LSTM) recurrent neurons to learn dynamic and hidden patterns to support disinformation detection. Our experimental findings show that TRNN significantly outperformed widely-used machine learning techniques in terms of precision, recall, F-score and accuracy, achieving consistently better classification performance in disinformation detection. A case study of Apple Inc.'s stock price movement demonstrates the potential usability of TRNN for secure knowledge management. The research contributes to developing novel approach and model, producing new information systems artifacts and dataset, and providing empirical findings of detecting online disinformation.

2.
Sci Rep ; 5: 10060, 2015 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-26091553

RESUMO

Social media is becoming a new battlefield for tobacco "wars". Evaluating the current situation is very crucial for the advocacy of tobacco control in the age of social media. To reveal the impact of tobacco-related user-generated content, this paper characterizes user interaction and social influence utilizing social network analysis and information theoretic approaches. Our empirical studies demonstrate that the exploding pro-tobacco content has long-lasting effects with more active users and broader influence, and reveal the shortage of social media resources in global tobacco control. It is found that the user interaction in the pro-tobacco group is more active, and user-generated content for tobacco promotion is more successful in obtaining user attention. Furthermore, we construct three tobacco-related social networks and investigate the topological patterns of these tobacco-related social networks. We find that the size of the pro-tobacco network overwhelms the others, which suggests a huge number of users are exposed to the pro-tobacco content. These results indicate that the gap between tobacco promotion and tobacco control is widening and tobacco control may be losing ground to tobacco promotion in social media.


Assuntos
Nicotiana , Mídias Sociais , Uso de Tabaco , Feminino , Humanos , Masculino
3.
Planta Med ; 81(2): 130-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25590366

RESUMO

Dendrobium officinale is an herbal medicine that has been clinically used to promote body fluid production. Previous works demonstrated that D. officinale polysaccharides could ameliorate symptoms of salivary secretion of patients with Sjögren's syndrome and in a respective mice model. In the present study, we investigated the underlying mechanism by which D. officinale polysaccharides activate M3 muscarinic receptors and induce extracellular calcium influx, leading to the translocation of aquaporin 5, a water channel protein, to the apical membrane of human submandibular gland epithelial cells. Enzymatic treatment of D. officinale polysaccharides suggested that they are hydrolyzed but do not permeate cell membranes. This finding supports the pharmacological activity of D. officinale polysaccharides to promote salivary secretion.


Assuntos
Aquaporina 5/metabolismo , Dendrobium/química , Extratos Vegetais/farmacologia , Polissacarídeos/farmacologia , Receptor Muscarínico M3/metabolismo , Síndrome de Sjogren/tratamento farmacológico , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Transporte Proteico/efeitos dos fármacos , Receptor Muscarínico M3/efeitos dos fármacos
4.
J Med Internet Res ; 17(1): e24, 2015 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-25608524

RESUMO

BACKGROUND: The commercial potential of social media is utilized by tobacco manufacturers and vendors for tobacco promotion online. However, the prevalence and promotional strategies of pro-tobacco content in social media are still not widely understood. OBJECTIVE: The goal of this study was to reveal what is presented by the tobacco industry, and how it promotes itself, on social media sites. METHODS: The top 70 popular cigarette brands are divided into two groups according to their retail prices: group H (brands with high retail prices) and group L (brands with low retail prices). Three comprehensive searches were conducted on Facebook, Wikipedia, and YouTube respectively using the top 70 popular cigarette brands as keywords. We identified tobacco-related content including history and culture, product features, health warnings, home page of cigarette brands, and Web-based tobacco shops. Furthermore, we examined the promotional strategies utilized in social media. RESULTS: According to the data collected from March 3, 2014 to March 10, 2014, 43 of the 70 representative cigarette brands had created 238 Facebook fan pages, 46 cigarette brands were identified in Wikipedia, and there were over 120,000 pro-tobacco videos on YouTube, associated with 61 cigarette brands. The main content presented on the three social media websites differs significantly. Wikipedia focuses on history and culture (67%, 32/48; P<.001). Facebook mainly covers history and culture (37%, 16/43; P<.001) and major products (35%, 15/43), while YouTube focuses on the features of major tobacco products (79%, 48/61; P=.04) and information about Web-based shops (49%, 30/61; P=.004). Concerning the content presented by groups H and L, there is no significant difference between the two groups. With regard to the promotional strategies used, sales promotions exist extensively in social media. Sales promotion is more prevalent on YouTube than on the other two sites (64%, 39/61 vs 35%, 15/43; P=.004). Generally, the sale promotions of higher-cost brands in social media are more prevalent than those of lower-cost brands (55%, 16/29 vs 7%, 1/14; P<.001 for Facebook; 78%, 28/36 vs 44%, 11/25; P=.005 for YouTube). CONCLUSIONS: The prevalence of cigarette brands in social media allows more pro-tobacco information to be accessed by online users. This dilemma indicates that corresponding regulations should be established to prevent tobacco promotion in social media.


Assuntos
Marketing/métodos , Mídias Sociais , Indústria do Tabaco , Custos e Análise de Custo , Humanos , Produtos do Tabaco/economia , Gravação de Videoteipe
5.
Int J Med Inform ; 76(11-12): 780-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-16996298

RESUMO

PURPOSE: Retrieving sufficient relevant information online is difficult for many people because they use too few keywords to search and search engines do not provide many support tools. To further complicate the search, users often ignore support tools when available. Our goal is to evaluate in a realistic setting when users use support tools and how they perceive these tools. METHODS: We compared three medical search engines with support tools that require more or less effort from users to form a query and evaluate results. We carried out an end user study with 23 users who were asked to find information, i.e., subtopics and supporting abstracts, for a given theme. We used a balanced within-subjects design and report on the effectiveness, efficiency and usability of the support tools from the end user perspective. CONCLUSIONS: We found significant differences in efficiency but did not find significant differences in effectiveness between the three search engines. Dynamic user support tools requiring less effort led to higher efficiency. Fewer searches were needed and more documents were found per search when both query reformulation and result review tools dynamically adjust to the user query. The query reformulation tool that provided a long list of keywords, dynamically adjusted to the user query, was used most often and led to more subtopics. As hypothesized, the dynamic result review tools were used more often and led to more subtopics than static ones. These results were corroborated by the usability questionnaires, which showed that support tools that dynamically optimize output were preferred.


Assuntos
Comportamento do Consumidor , Armazenamento e Recuperação da Informação/métodos , Aplicações da Informática Médica , Feminino , Humanos , Masculino , Inquéritos e Questionários , Unified Medical Language System
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...