Brazilian vegetarians diet quality markers and comparison with the general population : a nationwide cross-sectional study

Background Vegetarianism is an increasingly common practice worldwide. Despite good evidence from other countries regarding vegetarians’ diet quality, data from the Brazilian population is still scarce. Objective To characterize the vegetarian Brazilian population and evaluate their diet quality compared to the general Brazilian population. Methods We performed a nationwide cross-sectional study using an online self-administered questionnaire, previously validated for the Brazilian population, to evaluate diet quality markers of vegetarians. The invitation to participate in the survey was spread nationwide, aimed at vegetarian communities. Individuals who considered themselves vegetarians and were at least 18 years old were eligible to participate. The results on regular intake and intake adequacy were compared among vegetarians and between genders using the Pearson’s chi-square test. The body mass index (BMI) were analyzed by the Analysis of Variance (ANOVA) followed by Tukey post-hoc test. The Kolmogorov-Smirnov test verified normality. All analyses considered bilateral hypotheses and a significance level of 5% (p <0.05). Results Brazilian vegetarians presented better diet quality markers, such as higher regular weekly intake and adequate daily intake of fruits and vegetables, and lower regular intake of soft drinks when compared to the general Brazilian population. Vegetarians also presented a proportionally higher consumption of natural foods and lower consumption of processed foods. Among vegetarians, a higher proportion of vegans showed positive results regarding diet markers analysis, when compared to vegetarians, pesco-vegetarians, and semi-vegetarians. Conclusions Vegetarians showed better results of diet adequacy when compared to the general population in Brazil, and vegans fared better when compared with other vegetarians. Despite the good results found, a large proportion of the participants still did not achieve the fruits and vegetables daily intake, according to the World Health Organization recommendations

How Often Should I Access My Online Social Networks?

International audienceUsers of online social networks are faced with a conundrum of trying to be always informed without having enough time or attention budget to do so. The retention of users on online social networks has important implications, encompassing economic, psychological and infrastructure aspects. In this paper, we pose the following question: what is the optimal rate at which users should access a social network? To answer this question, we propose an analytical model to determine the value of an access (VoA) to the social network. In the simple setting considered in this paper, VoA is defined as the chance of a user accessing the network and obtaining new content. Clearly, VoA depends on the rate at which sources generate content and on the filtering imposed by the social network. Then, we pose an optimization problem wherein the utility of users grows with respect to VoA but is penalized by costs incurred to access the network. Using the proposed framework, we provide insights on the optimal access rate. Our results are parameterized using Facebook data, indicating the predictive power of the approach

Visibilidade no Facebook: Modelos, Medições e Implicações

National audienceFacebook news feed personalization algorithm has a significant impact , on a daily basis, on the lifestyle, mood and opinion of millions of Internet users. Nonetheless, such algorithms lack transparency challenging researchers to improve their fairness and accountability. In this paper, we propose a model to capture the dynamics of contents over a timeline (also known as news feed). The input to our model is a fundamental quantity associated to timelines, which we show that can be easily parameterized using real world data: the arrival rate of posts of a given publisher followed by the user. Using real world Facebook traces from the latest elections in Italy, we validate the accuracy of the proposed model and use the model for conterfactual what-if analysis.O Facebook tem um impacto significativo na vida de milhões de usuários da Internet, todos os dias. Entretanto, os mecanismos usados pelo Fa-cebook para filtrar mensagens apresentadas aos usuários não são de domínio público, motivando uma engenharia reversa dos mesmos. Neste trabalho, pro-pomos modelos e mediçmediç˜medições para melhor entender o comportamento de timeli-nes. Em particular, reportamos resultados sobre mediçmediç˜medições de visibilidade de fontes das eleiçeleiç˜eleições italianas de 2018, que motivam um modelo analítico para caracterizar a visibilidade de posts. Dentre as implicaçimplicaç˜implicações práticas de nossos estudos, indicamos seu potencial para inferir diferentes métricas de visibilidade a partir de medidas colhidas do sistema

Brazilian vegetarian population — influence of type of diet, motivation and sociodemographic variables on quality of life measured by specific tool (VEGQOL)

The adoption of a vegetarian diet has been associated with positive health outcomes. However, few studies evaluate the effect of this eating pattern on quality of life. Moreover, no specific instrument for the vegetarian population to measure the quality of life is available worldwide. Therefore, this study aimed to elaborate and validate a specific questionnaire to measure the quality of life in vegetarians. The Specific Vegetarian Quality of Life Questionnaire (VEGQOL) was constructed based on other instruments and studies related to vegetarianism. The content and semantic validation were performed by a group of experts, followed by a pilot study to evaluate the questionnaire acceptability and reproducibility. Discriminant validation was tested using the WHOQOL as the gold standard measure (Pearson correlation ranging from 0.302 of the domain 3 to 0.392 of the domain 2). Afterward, a nationwide survey was conducted using VEGQOL. Content and semantic validation selected 19 of the initial 30 items. VEGQOL presented good reproducibility (Cohen’s Kappa coefficient ranging from 0.361 to 0.730 and intraclass correlation coefficient of 0.820) and internal consistency (0.708), both adequate to evaluate the quality of life in vegetarians. The sample size (n = 5014 individuals, error of 3% at a level of significance of 5%) and distribution was representative of the Brazilian vegetarian population. In general, the quality of life of Brazilian vegetarians was considered satisfactory (VEGQOL cut off points 70–80). Among different types of vegetarians, the vegans showed better results with a VEGQOL mean value of 79.2 ± 10.7. Older individuals, the ones who adopted the diet for a longer time (VEGQOL mean value of 75.8 ± 12.7) and the ones who had other vegetarians in their social network (VEGQOL mean value of 74.6 ± 12.2) also had a better quality of life score. Individuals who adopted it for ethical or health reasons had a higher quality of life score. The questionnaire produced in this study is a useful tool for future research in this area. Results were better for vegans and for the ones who adopt the diet for ethical or health reasons

Modelando, Auditando e Prevendo a Visibilidade de Fontes no Facebook: Um Estudo de Caso nas Eleições Italianas

O Facebook tem um impacto significativo na vida de milhões de usuários da Internet, todos os dias.  Entretanto, os mecanismos usados pelo Facebook para filtrar mensagens apresentadas aos usuários não são de domínio público,   motivando uma engenharia reversa dos mesmos. Neste trabalho, propomos modelos e medições para melhor entender o comportamento de timelines.  Em particular, reportamos resultados sobre medições de visibilidade de fontes das eleições italianas de 2018, que  motivam  um modelo analítico para caracterizar a  visibilidade de posts.  Dentre as implicações práticas de nossos estudos, indicamos seu potencial para inferir diferentes métricas de visibilidade a partir de medidas colhidas do sistema

Quality of life of vegetarians during the covid-19 pandemic in Brazil

Health emergencies such as the COVID-19 pandemic can negatively impact quality of life (QoL) due to higher levels of stress, social isolation, and uncertainties. In this scenario, distinct population groups might react differently. Vegetarians, who follow a non-conventional dietary pattern, could be more vulnerable to the abrupt changes in normal life routine and economic instability. Therefore, this study aimed at evaluating if the current pandemic situation somehow affected vegetarians’ QoL. A cross-sectional study was carried out in Brazil between 28 July and 14 September 2020 to evaluate the QoL in vegetarians during the pandemic period. Vegetarian adults replied to an online survey that included the VEGQOL and WHOQOL-BREF instruments to evaluate QoL and questions related to the COVID-19 pandemic. A total of 1282 individuals participated. Only 3.8% had tested positive for COVID-19, but 39.9% affirmed having a family member who tested positive for the disease. Almost half (46.3%) of the sample had an income drop due to the pandemic. Results of QoL scores in the different subcategories of vegetarians were similar to previously published data. Individuals who had already tested positive for COVID-19 had lower QoL scores than those who did not test positive, but only in the VEGQOL. QoL was lower for the participants who declared that Sars-Cov-2 had already infected a family member for almost all the parameters evaluated. On the other hand, an income drop affected QoL only partially. Studying how vegetarians are influenced by such conditions contributes to the generation of relevant data that can be used to support healthcare and public policies in the future

Timelines are Publisher-Driven Caches: Analyzing and Shaping Timeline Networks

International audienceCache networks are one of the building blocks of information centric networks (ICNs). Most of the recent work on cache networks has focused on networks of request driven caches, which are populated based on users requests for content generated by publishers. However, user generated content still poses the most pressing challenges. For such content time-lines are the de facto sharing solution. In this paper, we establish a connection between time-lines and publisher-driven caches. We propose simple models and metrics to analyze publisher-driven caches, allowing for variable-sized objects. Then, we design two efficient algorithms for timeline workload shaping, leveraging admission and price control in order, for instance, to aid service providers to attain prescribed service level agreements