456 research outputs found

    Redefining “Misinformation,” “Disinformation,” and “Fake News”: Using Social Science Research to Form an Interdisciplinary Model of Online Limited Forums on Social Media Platforms

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    “Misinformation,” “disinformation,” and “fake news” have spread division and contention through online social media platforms, resulting in adverse effects to various areas of science, politics, and public health. This Comment takes a deeper look into the underlying motivations and beliefs behind this phenomenon by presenting a cohesive summarization of the empirical evidence gained from social science research. These terms are reclassified as “conflicting information” to deemphasize the considerations of fact or fiction and emphasize the empirical data showing these terms are social signifiers connotating “in-group” and “out-group” divisions. After developing this backdrop of social science research, the current legal proposals for regulating “conflicting information” are scrutinized, including section 230 of the Communications Decency Act, antitrust enforcement, classification of internet service providers as public utilities, and First Amendment limitations of regulating algorithmic data. This Comment then combines the empirical evidence and legal theory to form an interdisciplinary model of online limited forums. After developing a rudimentary view of how online limited forums would operate, it is proposed that a legislative recommendation be embedded into section 230’s “good faith” requirement. This legislative recommendation gives much needed guidance to online platforms trying to navigate the spread of conflicting information, while also bypassing the legal limitations making stricter methods of enforcement untenable

    A Search for Nitrogen Enriched Quasars in the Sloan Digital Sky Survey Early Data Release

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    A search for nitrogen-rich quasars in the Sloan Digital Sky Survey Early Data Release (SDSS EDR) catalog has yielded 16 candidates, including five with very prominent emission, but no cases with nitrogen emission as strong as in Q0353-383. The quasar Q0353-383 has long been known to have extremely strong nitrogen intercombination lines at lambda 1486 and lambda 1750 Angstroms, implying an anomalously high nitrogen abundance of about 15 times solar. It is still the only one of its kind known. A preliminary search through the EDR using the observed property of the weak C IV emission seen in Q0353-383 resulted in a sample of 23 objects with unusual emission or absorption-line properties, including one very luminous redshift 2.5 star-forming galaxy. We present descriptions, preliminary emission-line measurements, and spectra for all the objects discussed here.Comment: 20 pages, 5 figures, submitted to AJ; final refereed versio

    Impact of water saturation on seismoelectric transfer functions: a laboratory study of coseismic phenomenon

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    Seismic waves propagating in a porous medium, under favourable conditions, generate measurable electromagnetic fields due to electrokinetic effects. It has been proposed, following experimental and numerical studies, that these so-called ‘seismoelectromagnetic' couplings depend on pore fluid properties. The theoretical frame describing these phenomena are based on the original Biot's theory, assuming that pores are fluid-filled. We study here the impact of a partially saturated medium on amplitudes of those seismoelectric couplings by comparing experimental data to an effective fluid model. We have built a 1-m-length-scale experiment designed for imbibition and drainage of an homogeneous silica sand; the experimental set-up includes a seismic source, accelerometers, electric dipoles and capacitance probes in order to monitor seismic and seismoelectric fields during water saturation. Apparent velocities and frequency spectra (in the kiloHertz range) are derived from seismic and electrical measurements during experiments in varying saturation conditions. Amplitudes of seismic and seismoelectric waves and their ratios (i.e. transfer functions) are discussed using a spectral analysis performed by continuous wavelet transform. The experiments reveal that amplitude ratios of seismic to coseismic electric signals remain rather constant as a function of the water saturation in the Sw=[0.2-0.9] range, consistently with theoretically predicted transfer function

    Measurement of the Integrated Faraday Rotations of BL Lac Objects

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    We present the results of multi-frequency polarization VLA observations of radio sources from the complete sample of northern, radio-bright BL Lac objects compiled by H. Kuhr and G. Schmidt. These were used to determine the integrated rotation measures of 18 objects, 15 of which had never been measured previously, which hindered analysis of the intrinsic polarization properties of objects in the complete sample. These measurements make it possible to correct the observed orientations of the linear polarizations of these sources for the effect of Faraday rotation. The most probable origin for Faraday rotation in these objects is the Galactic interstellar medium. The results presented complete measurements of the integrated rotation measures for all 34 sources in the complete sample of BL Lac objects.Comment: 9 pages, 7 figure

    Post-traumatic stress disorder in sexually abused children: secure attachment as a protective factor

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    The aim of the present study was to examine the hypothesis that attachment and CSA interacted such that school aged CSA survivors with insecure attachment to parents would be at an elevated risk of developing PTSD and trauma symptoms. Participants (n = 111, ages 7-12) comprised two groups, child CSA survivors (n = 43) and a matched comparison group of children (n = 68) recruited from the community. Children completed the Child Attachment Interview as well as the Trauma Symptom Checklist for Children (TSCC). There was a significant interaction between sexual abuse history and attachment security, such that sexually abused children with insecure attachment representations had significantly more PTSD and trauma symptoms than sexually abused children with secure attachment to parents. The findings show that using a dual lens of attachment and CSA can facilitate identification children most at risk have important implications for understanding risk and resilience processes

    Measuring Reflective Functioning in Adolescents: Relations to Personality Disorders and Psychological Difficulties

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    Background: Reflective Functioning (RF) is considered to play a central role in risk and resilience for psychological difficulties such as borderline personality disorder (BPD) and has become an important treatment target of transdiagnostic psychosocial interventions like Mentalization Based Therapy. However, a lack of measures to assess RF in adolescents has hampered research that can further elucidate the role of RF in different types of psychopathology. Objective: The objective of the present study was to examine the validity of the Reflective Functioning Questionnaire for Youth (RFQ-Y), examine the factor structure of the french RFQ-Y, the relationship between RFQ-Y and social cognition, psychological difficulties, BPD and narcissistic personality disorders. Methods: A total of 533 adolescents and young adults (age 12 - 21) from the community completed the RFQ-Y, the Child Behaviour Checklist, the Borderline Personality Features Scale and the Pathological Narcissism Inventory. A subsample of 150 participants completed the Movie for the Assessment of Social Cognition (MASC). Results: Three factors were identified. Uncertainty/confusion was strongly positively correlated with psychological difficulties, especially symptoms of borderline personality disorder. Interest/curiosity was negatively correlated with and psychopathology and Excessive Certainty correlated significantly with grandiose narcissism. RFQ-Y factors correlated more strongly with psychopathology than the MASC scales. Conclusion: This study demonstrates the validity of self-report measures like the RFQ-Y and its utility for identifying problematic styles of mentalizing associated with increased risk of psychopathology in general, as well as difficulties like narcissism in particular

    Maternal and Child Sexual Abuse History: An Intergenerational Exploration of Children's Adjustment and Maternal Trauma-Reflective Functioning

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    Objective: The aim of the current study was to investigate associations, unique and interactive, between mothers’ and children’s histories of childhood sexual abuse (CSA) and children’s psychiatric outcomes using an intergenerational perspective. Further, we were particularly interested in examining whether maternal reflective functioning about their own trauma (T-RF) was associated with a lower likelihood of children’s abuse exposure (among children of CSA-exposed mothers). Methods: One hundred and eleven children (Mage = 9.53 years; 43 sexual abuse victims) and their mothers (Mage = 37.99; 63 sexual abuse victims) participated in this study. Mothers completed the Parent Development Interview (PDI), which yielded assessments of RF regarding their own experiences of abuse, and also reported on their children’s internalizing and externalizing symptoms. Results: Children of CSA-exposed mothers were more likely to have experienced CSA. A key result was that among CSA-exposed mothers, higher maternal T-RF regarding their own abuse was associated with lower likelihood of child CSA-exposure. Mothers’ and children’s CSA histories predicted children’s internalizing and externalizing symptoms, such that CSA exposure for mother or child was associated with greater symptomatology in children. Conclusion: The findings show that the presence of either maternal or child CSA is associated with more child psychological difficulties. Importantly in terms of identifying potential protective factors, maternal T-RF is associated with lower likelihood of CSA exposure in children of CSA-exposed mothers. We discuss these findings in the context of the need for treatments focusing on increasing T-RF in mothers and children in the context of abuse to facilitate adaptation and reduce the intergenerational risk

    On the X-ray emission of z~2 radio galaxies: IC scattering of the CMB & no evidence for fully-formed potential wells

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    We present the results of 20 ksec Chandra observations for each of 5 radio galaxies in the redshift range 2.0 < z < 2.6. For 4 of the 5 targets we detect unresolved X-ray components coincident with the radio nuclei. From spectral analysis of one of the cores and comparison to the empirical radio to X-ray luminosity ratio correlation, we find that obscuring material (n(HI)~10^22 cm^-2) may be surrounding the nuclei. We detect X-ray emission coincident with the radio hotspots or lobes in 4 of the 5 targets, which can be explained by Inverse-Compton (IC) scattering of CMB photons. The magnetic field strengths of ~100-200 muG that we derive agree with the equipartition magnetic field strengths. The relative ease with which the lobe X-ray emission is detected is a consequence of the (1+z)^4 increase in the energy density of the CMB. An HST image of one of the sources shows that the X-ray emission could also be produced by a reservoir of hot, shocked gas, as evidenced by a bright, optical bow-shock. By stacking our data we created a deep, 100 ksec exposure to search for diffuse X-ray emission from intra-cluster gas. We detect no diffuse emission and derive upper limits of ~1e+44 erg/s, thereby ruling out a virialized structure of cluster-size scale at z~2. The average number of soft X-ray sources in our fields is consistent with the number density of AGN in the Chandra Deep Fields. Their angular distribution shows no evidence for large-scale structure associated with the radio galaxies.Comment: 17 pages, 9 figures (3 color figs), 6 tables, Accepted for Publication in Astronomy & Astrophysic

    Constraints on Cosmic Strings from the LIGO-Virgo Gravitational-Wave Detectors

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    Cosmic strings can give rise to a large variety of interesting astrophysical phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by cusps are a promising observational signature. In this Letter we present a search for GWs from cosmic string cusps in data collected by the LIGO and Virgo gravitational wave detectors between 2005 and 2010, with over 625 days of live time. We find no evidence of GW signals from cosmic strings. From this result, we derive new constraints on cosmic string parameters, which complement and improve existing limits from previous searches for a stochastic background of GWs from cosmic microwave background measurements and pulsar timing data. In particular, if the size of loops is given by the gravitational backreaction scale, we place upper limits on the string tension GÎŒ below 10−8 in some regions of the cosmic string parameter space

    Radio spectra and polarisation properties of radio-loud Broad Absorption Line Quasars

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    We present multi-frequency observations of a sample of 15 radio-emitting Broad Absorption Line Quasars (BAL QSOs), covering a spectral range between 74 MHz and 43 GHz. They display mostly convex radio spectra which typically peak at about 1-5 GHz (in the observer's rest-frame), flatten at MHz frequencies, probably due to synchrotron self-absorption, and become steeper at high frequencies, i.e., >~ 20 GHz. VLA 22-GHz maps (HPBW ~ 80 mas) show unresolved or very compact sources, with linear projected sizes of <= 1 kpc. About 2/3 of the sample look unpolarised or weakly polarised at 8.4 GHz, frequency in which reasonable upper limits could be obtained for polarised intensity. Statistical comparisons have been made between the spectral index distributions of samples of BAL and non-BAL QSOs, both in the observed and the rest-frame, finding steeper spectra among non-BAL QSOs. However constraining this comparison to compact sources results in no significant differences between both distributions. This comparison is consistent with BAL QSOs not being oriented along a particular line of sight. In addition, our analysis of the spectral shape, variability and polarisation properties shows that radio BAL QSOs share several properties common to young radio sources like Compact Steep Spectrum (CSS) or Gigahertz-Peaked Spectrum (GPS) sources.Comment: 18 pages, 11 Postscript figures, 12 Tables. Accepted for publication in MNRA
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