375 research outputs found

    Search Bias Quantification: Investigating Political Bias in Social Media and Web Search

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    Users frequently use search systems on the Web as well as online social media to learn about ongoing events and public opinion on personalities. Prior studies have shown that the top-ranked results returned by these search engines can shape user opinion about the topic (e.g., event or person) being searched. In case of polarizing topics like politics, where multiple competing perspectives exist, the political bias in the top search results can play a significant role in shaping public opinion towards (or away from) certain perspectives. Given the considerable impact that search bias can have on the user, we propose a generalizable search bias quantification framework that not only measures the political bias in ranked list output by the search system but also decouples the bias introduced by the different sources—input data and ranking system. We apply our framework to study the political bias in searches related to 2016 US Presidential primaries in Twitter social media search and find that both input data and ranking system matter in determining the final search output bias seen by the users. And finally, we use the framework to compare the relative bias for two popular search systems—Twitter social media search and Google web search—for queries related to politicians and political events. We end by discussing some potential solutions to signal the bias in the search results to make the users more aware of them.publishe

    Chemical characteristics of PM<SUB>10</SUB> aerosols and airmass trajectories over Bay of Bengal and Arabian sea during ICARB

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    For the first time, chemical characterization of PM10 aerosols was attempted over the Bay of Bengal (BoB) and Arabian Sea (AS) during the ICARB campaign. Dominance of SO42-, NH4+ and NO3- was noticed over both the regions which indicated the presence of ammonium sulphate and ammonium nitrate as major water soluble particles playing a very important role in the radiation budget. It was observed that all the chemical constituents had higher concentrations over Bay of Bengal as compared to Arabian Sea. Higher concentrations were observed near the Indian coast showing influence of landmass indicating that gaseous pollutants like SO2, NH3 and NO x are transported over to the sea regions which consequently contribute to higher SO42-, NH4+ and NO3- aerosols respectively. The most polluted region over BoB was 13&#176;-19&#176;N and 70&#176;-90&#176;E while it was near 11&#176;N and 75&#176;E over AS. Although the concentrations were higher over Bay of Bengal for all the chemical constituents of PM10 aerosols, per cent non-sea salt (nss) fraction (with respect to Na) was higher over Arabian Sea. Very low Ca2+ concentration was observed at Arabian Sea which led to higher atmospheric acidity as compared to BoB. Nss SO42-alone contributed 48% of total water soluble fraction over BoB as well as AS. Ratios SO42- /NO3- over both the regions (7.8 and 9 over BoB and AS respectively) were very high as compared to reported values at land sites like Allahabad (0.63) and Kanpur (0.66) which may be due to very low NO.3 over sea regions as compared to land sites. Air trajectory analysis showed four classes: (i) airmass passing through Indian land, (ii) from oceanic region, (iii) northern Arabian Sea and Middle East and (iv) African continent. The highest nss SO42- was observed during airmasses coming from the Indian land side while lowest concentrations were observed when the air was coming from oceanic regions. Moderate concentrations of nss SO2- 4 were observed when air was seen moving from the Middle East and African continent. The pH of rainwater was observed to be in the range of 5.9-6.5 which is lower than the values reported over land sites. Similar feature was reported over the Indian Ocean during INDOEX indicating that marine atmosphere had more free acidity than land atmosphere

    The Road to Popularity: The Dilution of Growing Audience on Twitter

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    On social media platforms, like Twitter, users are often interested in gaining more influence and popularity by growing their set of followers, aka their audience. Several studies have described the properties of users on Twitter based on static snapshots of their follower network. Other studies have analyzed the general process of link formation. Here, rather than investigating the dynamics of this process itself, we study how the characteristics of the audience and follower links change as the audience of a user grows in size on the road to user's popularity. To begin with, we find that the early followers tend to be more elite users than the late followers, i.e., they are more likely to have verified and expert accounts. Moreover, the early followers are significantly more similar to the person that they follow than the late followers. Namely, they are more likely to share time zone, language, and topics of interests with the followed user. To some extent, these phenomena are related with the growth of Twitter itself, wherein the early followers tend to be the early adopters of Twitter, while the late followers are late adopters. We isolate, however, the effect of the growth of audiences consisting of followers from the growth of Twitter's user base itself. Finally, we measure the engagement of such audiences with the content of the followed user, by measuring the probability that an early or late follower becomes a retweeter

    Semidefinite Representation of the kk-Ellipse

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    The kk-ellipse is the plane algebraic curve consisting of all points whose sum of distances from kk given points is a fixed number. The polynomial equation defining the kk-ellipse has degree 2k2^k if kk is odd and degree 2k(kk/2)2^k{-}\binom{k}{k/2} if kk is even. We express this polynomial equation as the determinant of a symmetric matrix of linear polynomials. Our representation extends to weighted kk-ellipses and kk-ellipsoids in arbitrary dimensions, and it leads to new geometric applications of semidefinite programming.Comment: 16 pages, 5 figure

    Scavenging in Northwestern Europe: A Survey of UK Police Specialist Search Officers

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    Physical search methods used by police specialist searchers are based on counter-terrorism methods and not on the search and recovery of outdoor surface deposited human remains, nevertheless these methods are applied to scenes involving human remains. Additionally, there is limited published forensic literature within Northwestern Europe on the potential taphonomic agents within this region that are capable of modifying human remains through scavenging, scattering and removal. The counter-terrorism basis in physical search methods and the gap in published forensic literature regarding scavenging in this region can potentially impede searchers’ abilities to adapt physical search methods to their full efficiency in the search and recovery of scavenged human remains. This paper analysed through a questionnaire survey of 111 police specialist searchers, within the U.K., the impact of animal scavenging on the search and recovery of human remains.According to questionnaire respondents’ experiences and knowledge, the occurrence of scavenging at scenes in which respondents took part in a physical search for human remains was common (63.46%,n= 66) and happened most frequently with surface deposits (68.25%,n= 43). Scavenging resulted in the recovery of incomplete sets of remains (59.79%, n= 58) and influenced search perimeters (58.33%, n= 35). Scavenging also affected recovery rates at scene searches (80.43%,n= 74) that included the use of cadaver dogs with police handlers. The impact scavengers within this region have on different crime scene scenarios and search methods is not reflected in current published literature or search standards

    Uric acid in men with acute stroke

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    Abstract Higher levels of uric acid in men as compared to women can be a reason behind greater incidence of stroke in men. The objective of the present study was to evaluate the levels of uric acid in men with acute stroke and correlate with stroke severity.For the purpose of the study ,50 male patients of acute stroke admitted to the hospital and 50 age matched healthy controls were included in the study. Routine biochemical parameters including fasting blood glucose, uric acid and lipid profile were assessed in serum obtained from 5 ml of fasting blood sample. Patients with kidney or liver diseases, malignancies, diuretic use, alcohol intake, on iron or antioxidant therapy were excluded from the study. Initial stroke severity was measured by the National Institute of Health Stroke (NIHS) scale. It was found that , among the 50 cases, 38(76%) had ischemic stroke and 12(24%) had hemorrhagic stroke. Serum uric acid levels were very significantly higher in cases (p&lt;0.001) than controls. There was strong positive correlation between uric acid levels and initial stroke severity (p=0.006, r=0.386). Also, serum uric acid showed a statistically significant correlation with fasting blood glucose, TG and VLDL and an inverse association with HDL in both cases and controls. The conclusion drawn was that the significantly higher levels of uric acid in men with stroke and the positive association of uric acid with stroke severity suggest a possible role of uric acid as a risk factor for stroke in men

    Effectiveness of conservative non-pharmacological interventions in people with muscular dystrophies: a systematic review and meta-analysis.

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    INTRODUCTION: Management of muscular dystrophies (MD) relies on conservative non-pharmacological treatments, but evidence of their effectiveness is limited and inconclusive. OBJECTIVE: To investigate the effectiveness of conservative non-pharmacological interventions for MD physical management. METHODS: This systematic review and meta-analysis followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and searched Medline, CINHAL, Embase, AMED and Cochrane Central Register of Controlled Trial (inception to August 2022). Effect size (ES) and 95% Confidence Interval (CI) quantified treatment effect. RESULTS: Of 31,285 identified articles, 39 studies (957 participants), mostly at high risk of bias, were included. For children with Duchenne muscular dystrophy (DMD), trunk-oriented strength exercises and usual care were more effective than usual care alone in improving distal upper-limb function, sitting and dynamic reaching balance (ES range: 0.87 to 2.29). For adults with Facioscapulohumeral dystrophy (FSHD), vibratory proprioceptive assistance and neuromuscular electrical stimulation respectively improved maximum voluntary isometric contraction and reduced pain intensity (ES range: 1.58 to 2.33). For adults with FSHD, Limb-girdle muscular dystrophy (LGMD) and Becker muscular dystrophy (BMD), strength-training improved dynamic balance (sit-to-stand ability) and self-perceived physical condition (ES range: 0.83 to 1.00). A multicomponent programme improved perceived exertion rate and gait in adults with Myotonic dystrophy type 1 (DM1) (ES range: 0.92 to 3.83). CONCLUSIONS: Low-quality evidence suggests that strength training, with or without other exercise interventions, may improve perceived exertion, distal upper limb function, static and dynamic balance, gait and well-being in MD. Although more robust and larger studies are needed, current evidence supports the inclusion of strength training in MD treatment, as it was found to be safe
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