Local Ranking Problem on the BrowseGraph

The "Local Ranking Problem" (LRP) is related to the computation of a centrality-like rank on a local graph, where the scores of the nodes could significantly differ from the ones computed on the global graph. Previous work has studied LRP on the hyperlink graph but never on the BrowseGraph, namely a graph where nodes are webpages and edges are browsing transitions. Recently, this graph has received more and more attention in many different tasks such as ranking, prediction and recommendation. However, a web-server has only the browsing traffic performed on its pages (local BrowseGraph) and, as a consequence, the local computation can lead to estimation errors, which hinders the increasing number of applications in the state of the art. Also, although the divergence between the local and global ranks has been measured, the possibility of estimating such divergence using only local knowledge has been mainly overlooked. These aspects are of great interest for online service providers who want to: (i) gauge their ability to correctly assess the importance of their resources only based on their local knowledge, and (ii) take into account real user browsing fluxes that better capture the actual user interest than the static hyperlink network. We study the LRP problem on a BrowseGraph from a large news provider, considering as subgraphs the aggregations of browsing traces of users coming from different domains. We show that the distance between rankings can be accurately predicted based only on structural information of the local graph, being able to achieve an average rank correlation as high as 0.8

Distilling Information Reliability and Source Trustworthiness from Digital Traces

Online knowledge repositories typically rely on their users or dedicated editors to evaluate the reliability of their content. These evaluations can be viewed as noisy measurements of both information reliability and information source trustworthiness. Can we leverage these noisy evaluations, often biased, to distill a robust, unbiased and interpretable measure of both notions? In this paper, we argue that the temporal traces left by these noisy evaluations give cues on the reliability of the information and the trustworthiness of the sources. Then, we propose a temporal point process modeling framework that links these temporal traces to robust, unbiased and interpretable notions of information reliability and source trustworthiness. Furthermore, we develop an efficient convex optimization procedure to learn the parameters of the model from historical traces. Experiments on real-world data gathered from Wikipedia and Stack Overflow show that our modeling framework accurately predicts evaluation events, provides an interpretable measure of information reliability and source trustworthiness, and yields interesting insights about real-world events.Comment: Accepted at 26th World Wide Web conference (WWW-17

Food additives: Sodium benzoate, potassium sorbate, azorubine, and tartrazine modify the expression of NFκB, GADD45α, and MAPK8 genes

It has been reported that some of the food additives may cause sensitization, inflammation of tissues, and potentially risk factors in the development of several chronic diseases. Thus, we hypothesized that expressions of common inflammatory molecules – known to be involved in the development of various inflammatory conditions and cancers – are affected by these food additives. We investigated the effects of commonly used food preservatives and artificial food colorants based on the expressions of NFκB, GADD45α, and MAPK8 (JNK1) from the tissues of liver. RNA was isolated based on Trizol protocol and the activation levels were compared between the treated and the control groups. Tartrazine alone could elicit effects on the expressions of NFκB (p = 0.013) and MAPK8 (p = 0.022). Azorubine also resulted in apoptosis according to MAPK8 expression (p = 0.009). Preservatives were anti-apoptotic in high dose. Sodium benzoate (from low to high doses) dose-dependently silenced MAPK8 expression (p = 0.004 to p = 0.002). Addition of the two preservatives together elicited significantly greater expression of MAPK8 at half-fold dose (p = 0.002) and at fivefold dose (p = 0.008). This study suggests that some of the food preservatives and colorants can contribute to the activation of inflammatory pathways

A Nearly Four-Year Longitudinal Study of Search-Engine Poisoning

We investigate the evolution of search-engine poisoning using data on over 5 million search results collected over nearly 4 years. We build on prior work investigating search-redirection attacks, where criminals compromise high-ranking websites and direct search traf-fic to the websites of paying customers, such as unlicensed phar-macies who lack access to traditional search-based advertisements. We overcome several obstacles to longitudinal studies by amalga-mating different resources and adapting our measurement infras-tructure to changes brought by adaptations by both legitimate op-erators and attackers. Our goal is to empirically characterize how strategies for carrying out and combating search poisoning have evolved over a relatively long time period. We investigate how the composition of search results themselves has changed. For in-stance, we find that search-redirection attacks have steadily grown to take over a larger share of results (rising from around 30 % in late 2010 to a peak of nearly 60 % in late 2012), despite efforts by search engines and browsers to combat their effectiveness. We also study the efforts of hosts to remedy search-redirection attacks. We find that the median time to clean up source infections has fallen from around 30 days in 2010 to around 15 days by late 2013, yet the number of distinct infections has increased considerably over the same period. Finally, we show that the concentration of traffic to the most successful brokers has persisted over time. Further, these brokers have been mostly hosted on a few autonomous systems, which indicates a possible intervention strategy. Categories and Subject Descriptors K.4.1 [Public Policy Issues]: Abuse and crime involving comput-er

Confirmation of the Chinese version of the Problematic Internet Use Questionnaire Short Form (PIUQ-SF)

Although an increasing number of studies have focused on problematic Internet use, numerous measures exist with only modest investigation into their reliability and validity, both within and across different cultures (Király et al. 2015). The most frequently used questionnaire is the Internet Addiction Test (Young 1998). However, its factor structure appears to be unstable (e.g., Fernandez-Villa et al. 2015; Pontesetal. 2014). Koronczai et al. (2011) suggested that a suitable measure should fit six basic requirements. More specifically, it should be (i) comprehensive, that is examining more, possibly all, aspects of problematic Internet use; (ii) as concise as possible, in order to be able to assess the more impulsive population, and to use in time-limited surveys (or having different forms with different length). Such a measure should be (iii) reliable and valid for different methods of data collection (e.g. online, paper-and-pencil self-rating, face-to-face); as well as (iv) for different age groups (e.g. adolescents and adults), and (v) in different cultural settings. Finally, (vi) cut-off scores should be defined on the basis of clinical examination. The Problematic Internet Use Questionnaire (PIUQ) (Demetrovics et al. 2008) fulfills several of the aforementioned criteria. The 18-item PIUQ is a comprehensive measure that assesses three basic aspects of problematic Internet use (i.e., obsession, neglect, and control disorder). The 18-item and the shorter 9-item versions of the PIUQ have a reliable structure, and are suitable for time-limited surveys and have proved to be valid across various methods of data collection (i.e., online as well as paper-pencil) and age groups (Demetrovics et al. 2008; Koronczai et al. 2011). However, its implementation has so far mostly taken place in Western individualistic cultures (Kelley and Gruber 2010, 2013; Koronczai et al. 2011; Zahodne et al. 2011. To date, the PIUQ has also been applied in a survey in Iran with good Cronbach’s alpha coefficients and subscales (Mazhari 2012a, 2012b). Consequently, validation of the questionnaire in a culture that is significantly different from the Western culture is needed. Accordingly, the aim of the present study was the validation of the 9-item PIUQ among the Chinese population

Effect of ethnomedicinal plants used in folklore medicine in Jordan as antibiotic resistant inhibitors on Escherichia coli

<p>Abstract</p> <p>Background</p> <p><it>Escherichia coli </it>occurs naturally in the human gut; however, certain strains that can cause infections, are becoming resistant to antibiotics. Multidrug-resistant <it>E. coli </it>that produce extended-spectrum β lactamases (ESBLs), such as the CTX-M enzymes, have emerged within the community setting as an important cause of urinary tract infections (UTIs) and bloodstream infections may be associated with these community-onsets. This is the first report testing the antibiotic resistance-modifying activity of nineteen Jordanian plants against multidrug-resistant <it>E. coli</it>.</p> <p>Methods</p> <p>The susceptibility of bacterial isolates to antibiotics was tested by determining their minimum inhibitory concentrations (MICs) using a broth microdilution method. Nineteen Jordanian plant extracts (<it>Capparis spinosa </it>L., <it>Artemisia herba-alba Asso, Echinops polyceras </it>Boiss., <it>Gundelia tournefortii </it>L, <it>Varthemia iphionoides </it>Boiss. & Blanche, <it>Eruca sativa Mill</it>., <it>Euphorbia macroclada </it>L., <it>Hypericum trequetrifolium </it>Turra, <it>Achillea santolina </it>L., <it>Mentha longifolia </it>Host, <it>Origanum syriacum </it>L., <it>Phlomis brachydo</it>(Boiss.) Zohary, <it>Teucrium polium </it>L., <it>Anagyris foetida </it>L., <it>Trigonella foenum-graecum </it>L., <it>Thea sinensis </it>L., <it>Hibiscus sabdariffa </it>L., <it>Lepidium sativum </it>L., <it>Pimpinella anisum </it>L.) were combined with antibiotics, from different classes, and the inhibitory effect of the combinations was estimated.</p> <p>Results</p> <p>Methanolic extracts of the plant materials enhanced the inhibitory effects of chloramphenicol, neomycin, doxycycline, cephalexin and nalidixic acid against both the standard strain and to a lesser extent the resistant strain of <it>E. coli</it>. Two edible plant extracts (<it>Gundelia tournefortii L</it>. and <it>Pimpinella anisum L</it>.) generally enhanced activity against resistant strain. Some of the plant extracts like <it>Origanum syriacum </it>L.(Labiateae), <it>Trigonella foenum- graecum </it>L.(Leguminosae), <it>Euphorbia macroclada </it>(Euphorbiaceae) and <it>Hibiscus sabdariffa </it>(Malvaceae) did not enhance the activity of amoxicillin against both standard and resistant <it>E. coli</it>. On the other hand combinations of amoxicillin with other plant extracts used showed variable effect between standard and resistant strains. Plant extracts like <it>Anagyris foetida </it>(Leguminosae) and <it>Lepidium sativum </it>(Umbelliferae) reduced the activity of amoxicillin against the standard strain but enhanced the activity against resistant strains. Three edible plants; Gundelia <it>tournefortii </it>L. (Compositae) <it>Eruca sativa </it>Mill. (Cruciferae), and <it>Origanum syriacum </it>L. (Labiateae), enhanced activity of clarithromycin against the resistant <it>E. coli </it>strain.</p> <p>Conclusion</p> <p>This study probably suggests possibility of concurrent use of these antibiotics and plant extracts in treating infections caused by <it>E. coli </it>or at least the concomitant administration may not impair the antimicrobial activity of these antibiotics.</p

The relationship between personality traits, psychopathological symptoms, and problematic internet use: a complex mediation model

Background: There are many empirical studies that demonstrate the associations between problematic internet use, psychopathological symptoms, and personality traits. However, complex models are scarce. Objective: The aim of this study was to build and test a mediation model based on problematic internet use, psychopathological symptoms, and personality traits. Methods: Data were collected from a medical addiction center (43 internet addicts) and internet cafés (222 customers) in Beijing (Mean age = 22.45 years, SD = 4.96; 90.2% males). Path analysis was applied to test the mediation models using structural equation modelling. Results: Based on the preliminary analyses (correlations and linear regression), two different models were built. In the first model, low conscientiousness and depression had a direct significant influence on problematic internet use. The indirect effect of conscientiousness – via depression – was non-significant. Emotional stability only affected problematic internet use indirectly, via depressive symptoms. In the second model, low conscientiousness also had a direct influence on problematic internet use, while the indirect path via the Global Severity Index was again non-significant. Emotional stability impacted problematic internet use indirectly via the Global Severity Index, while it had no direct effect on it, as in the first model. Conclusion: Personality traits (i.e., conscientiousness as a protective factor and neuroticism as a risk factor) play a significant role in problematic internet use, both directly and indirectly (via distress level)

Substance use and psychological disorders among art and non-art university students: an empirical self-report survey

Media stories often suggest that those working in the creative arts appear to use and abuse psychoactive substances. The aim of the present study was to analyze the relationship between the use of psychoactive substances and the presence of psychological disorders among art and non-art students. Questionnaires related to these two areas were completed by 182 art students in higher education and a control group of 704 non-art university students. To assess psychoactive substance use, a structured questionnaire including the Cannabis Abuse Screening Test (CAST) and the Alcohol Use Disorders Identification Test (AUDIT) was administered to participants. Psychological disorders were assessed using the Hungarian version of the Brief Symptom Inventory (BSI) and the Global Severity Index (GSI). After analyzing the data, significant differences were found between the two groups regarding their first use of psychoactive substances. Art students' current substance use was found to be significantly more frequent compared to the control group. In relation to psychological disorders, art students scored significantly higher on three scales of the BSI (i.e., psychoticism, hostility, and phobic anxiety). Overall, a significantly higher proportion of artists were labeled as "problematic" using the GSI. The results suggest that artists have a higher risk of both substance use and experiencing psychological disorders

Psychometric properties of the Problematic Internet Use Questionnaire Short-Form (PIUQ-SF-6) in a nationally representative sample of adolescents

Despite the large number of measurement tools developed to assess problematic Internet use, numerous studies use measures with only modest investigation into their psychometric properties. The goal of the present study was to validate the short (6-item) version of the Problematic Internet Use Questionnaire (PIUQ) on a nationally representative adolescent sample (n = 5,005; mean age 16.4 years, SD = 0.87) and to determine a statistically established cut-off value. Data were collected within the framework of the European School Survey Project on Alcohol and Other Drugs project. Results showed an acceptable fit of the original three-factor structure to the data. In addition, a MIMIC model was carried out to justify the need for three distinct factors. The sample was divided into users at-risk of problematic Internet use and those with no-risk using a latent profile analysis. Two latent classes were obtained with 14.4% of adolescents belonging to the at-risk group. Concurrent and convergent validity were tested by comparing the two groups across a number of variables (i.e., time spent online, academic achievement, self-esteem, depressive symptoms, and preferred online activities). Using the at-risk latent profile analysis class as the gold standard, a cut-off value of 15 (out of 30) was suggested based on sensitivity and specificity analyses. In conclusion, the brief version of the (6-item) PIUQ also appears to be an appropriate measure to differentiate between Internet users at risk of developing problematic Internet use and those not at risk. Furthermore, due to its brevity, the shortened PIUQ is advantageous to utilize within large-scale surveys assessing many different behaviors and/or constructs by reducing the overall number of survey questions, and as a consequence, likely increasing completion rates