6,984 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

    With No Deliberate Speed: The Segregation of Roma Children in Europe

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    In this study, by taking the advantage of both inorganic ZnO nanoparticles and the organic material chitosan as a composite seed layer, we have fabricated well-aligned ZnO nanorods on a gold-coated glass substrate using the hydrothermal growth method. The ZnO nanoparticles were characterized by the Raman spectroscopic techniques, which showed the nanocrystalline phase of the ZnO nanoparticles. Different composites of ZnO nanoparticles and chitosan were prepared and used as a seed layer for the fabrication of well-aligned ZnO nanorods. Field emission scanning electron microscopy, energy dispersive X-ray, high-resolution transmission electron microscopy, X-ray diffraction, and infrared reflection absorption spectroscopic techniques were utilized for the structural characterization of the ZnO nanoparticles/chitosan seed layer-coated ZnO nanorods on a gold-coated glass substrate. This study has shown that the ZnO nanorods are well-aligned, uniform, and dense, exhibit the wurtzite hexagonal structure, and are perpendicularly oriented to the substrate. Moreover, the ZnO nanorods are only composed of Zn and O atoms. An optical study was also carried out for the ZnO nanoparticles/chitosan seed layer-coated ZnO nanorods, and the obtained results have shown that the fabricated ZnO nanorods exhibit good crystal quality. This study has provided a cheap fabrication method for the controlled morphology and good alignment of ZnO nanorods, which is of high demand for enhancing the working performance of optoelectronic devices

    using management information system to evaluate quality of care at tertiary care hospital’s stroke centre

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    To find out the average length of stay, the rate of I/V catheter cellulites, the rate of bed sores among patients in stroke centre and determine the mortality rates. Methodology: This is a descriptive study, carried out at a tertiary care hospital over the period of six months. Data was analyzed by SPSS version 15.0. Result: Total numbers of patients were 36 from January 1 to June 30, 2007 at Stroke Center Liaquat National Hospital. The mean length of stay was 8.17 ±5.81 days. Patients had cellulitis (intravenous) 97.2%, only 2.8% of patients did not develop. The rate of bed sore was 41.7%. Conclusion: By effective implementation of the Management Information System (MIS) in health care delivery system we can find patients clinical issues and can reduce their length of stay

    The maintenance of elevated active chlorine levels in the Antarctic lower stratosphere through HCl null cycles

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    The Antarctic ozone hole arises from ozone destruction driven by elevated levels of ozone destroying ("active") chlorine in Antarctic spring. These elevated levels of active chlorine have to be formed first and then maintained throughout the period of ozone destruction. It is a matter of debate how this maintenance of active chlorine is brought about in Antarctic spring, when the rate of formation of HCl (considered to be the main chlorine deactivation mechanism in Antarctica) is extremely high. Here we show that in the heart of the ozone hole (16–18 km or 85–55 hPa, in the core of the vortex), high levels of active chlorine are maintained by effective chemical cycles (referred to as HCl null cycles hereafter). In these cycles, the formation of HCl is balanced by immediate reactivation, i.e. by immediate reformation of active chlorine. Under these conditions, polar stratospheric clouds sequester HNO3 and thereby cause NO2 concentrations to be low. These HCl null cycles allow active chlorine levels to be maintained in the Antarctic lower stratosphere and thus rapid ozone destruction to occur. For the observed almost complete activation of stratospheric chlorine in the lower stratosphere, the heterogeneous reaction HCl + HOCl is essential; the production of HOCl occurs via HO2 + ClO, with the HO2 resulting from CH2O photolysis. These results are important for assessing the impact of changes of the future stratospheric composition on the recovery of the ozone hole. Our simulations indicate that, in the lower stratosphere, future increased methane concentrations will not lead to enhanced chlorine deactivation (through the reaction CH4 + Cl  ⟶  HCl + CH3) and that extreme ozone destruction to levels below  ≈ 0.1 ppm will occur until mid-century

    Knowledge of primary paediatric care providers regarding attention deficit hyperactivity disorder and learning disorder: a study from Pakistan

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    Introduction: Attention deficit hyperactivity disorder (ADHD) and learning disorder (LD) remain prevalent globally and are also speculated to have a high occurrence in Pakistan. An early diagnosis and intervention in these disabilities is imperative for achieving good clinical and functional outcomes. This can be ensured by an effective screening at the level of primary paediatric care in the developing countries. We aimed to explore the ability of general practitioners (GPs) and paediatricians in Pakistan to screen for ADHD and LD based on their awareness regarding the risk factors and symptomatology of ADHD and LD. Methods: A total of 96 paediatricians and 98 GPs practising in Karachi, Pakistan were included in the study. Data was collected employing a self-administered questionnaire. Results: Only 13.7 percent of the GPs and 21.6 percent of the paediatricians were shown to have knowledge sufficient to effectively screen for / diagnose ADHD. Alarmingly, not a single GP was adequately familiar with the established risk factors and clinical symptoms of LD. The level of knowledge was not influenced by age, gender, and clinical practice attributes of the physicians. Doctors who regularly read medical journals and attend medical education seminars showed slightly better trends. Conclusion : We hypothesise that this demonstrated lack of knowledge at the level of primary care in Pakistan prevents an early screening of ADHD and LD. A multipronged strategy targeted at the provision of objective screening tools for primary paediatric care providers, regular continuing medical education seminars and an emphasis on paediatric mental health in undergraduate and postgraduate curricula may ensure an early detection of ADHD and LD in Pakistan

    Recall errors in a weekly survey of diarrhoea in Guatemala: determining the optimal length of recall

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    We measured the recall error, optimal recall length and factors associated with diarrhoea in a weekly survey. Data was taken from a year-long randomized controlled trial in which characteristics of diarrhoeal episodes were recorded weekly. We labelled the recall period as days 1-6, day I being the day before the visit. Recall error was the percentage difference between the number of episodes reported to begin on a particular day and the mean for days I and 2. Generalized estimating equations were used to determine associations. Recall error was 37% on day 3 and 51% on day 5. The error was less in younger children (by 10%), severe episodes (by 29%) and when blood was present in the stool (by 18%). Diarrhoea was underreported when the recall period extended beyond 2 days. Surveys that use longer recall periods risk underestimating diarrhoea incidence and selectively capturing more severe episodes

    Motion of a Vector Particle in a Curved Spacetime. II First Order Correction to a Geodesic in a Schwarzschild Background

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    The influence of spin on a photon's motion in a Schwarzschild and FRW spacetimes is studied. The first order correction to the geodesic motion is found. It is shown that unlike the world-lines of spinless particles, the photons world-lines do not lie in a plane.Comment: 14 pages, LaTeX2e, second paper in the series (the first one: gr-qc/0110067), replaced with typos and style corrected version, accepted in MPL
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