155 research outputs found
Реалізація стратегії уникання прямої відповіді у нестандартних комунікативних ситуаціях інституціонального дискурсу
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Towards Analyzing the Bias of News Recommender Systems Using Sentiment and Stance Detection
News recommender systems are used by online news providers to alleviate information overload and to provide personalized content to users. However, algorithmic news curation has been hypothesized to create filter bubbles and to intensify users' selective exposure, potentially increasing their vulnerability to polarized opinions and fake news. In this paper, we show how information on news items' stance and sentiment can be utilized to analyze and quantify the extent to which recommender systems suffer from biases. To that end, we have annotated a German news corpus on the topic of migration using stance detection and sentiment analysis. In an experimental evaluation with four different recommender systems, our results show a slight tendency of all four models for recommending articles with negative sentiments and stances against the topic of refugees and migration. Moreover, we observed a positive correlation between the sentiment and stance bias of the text-based recommenders and the preexisting user bias, which indicates that these systems amplify users' opinions and decrease the diversity of recommended news. The knowledge-aware model appears to be the least prone to such biases, at the cost of predictive accuracy
NeMig -- A Bilingual News Collection and Knowledge Graph about Migration
News recommendation plays a critical role in shaping the public's worldviews
through the way in which it filters and disseminates information about
different topics. Given the crucial impact that media plays in opinion
formation, especially for sensitive topics, understanding the effects of
personalized recommendation beyond accuracy has become essential in today's
digital society. In this work, we present NeMig, a bilingual news collection on
the topic of migration, and corresponding rich user data. In comparison to
existing news recommendation datasets, which comprise a large variety of
monolingual news, NeMig covers articles on a single controversial topic,
published in both Germany and the US. We annotate the sentiment polarization of
the articles and the political leanings of the media outlets, in addition to
extracting subtopics and named entities disambiguated through Wikidata. These
features can be used to analyze the effects of algorithmic news curation beyond
accuracy-based performance, such as recommender biases and the creation of
filter bubbles. We construct domain-specific knowledge graphs from the news
text and metadata, thus encoding knowledge-level connections between articles.
Importantly, while existing datasets include only click behavior, we collect
user socio-demographic and political information in addition to explicit click
feedback. We demonstrate the utility of NeMig through experiments on the tasks
of news recommenders benchmarking, analysis of biases in recommenders, and news
trends analysis. NeMig aims to provide a useful resource for the news
recommendation community and to foster interdisciplinary research into the
multidimensional effects of algorithmic news curation.Comment: Accepted at the 11th International Workshop on News Recommendation
and Analytics (INRA 2023) in conjunction with ACM RecSys 202
Towards analyzing the bias of news recommender systems using sentiment and stance detection
News recommender systems are used by online news providers to alleviate
information overload and to provide personalized content to users. However,
algorithmic news curation has been hypothesized to create filter bubbles and to
intensify users' selective exposure, potentially increasing their vulnerability
to polarized opinions and fake news. In this paper, we show how information on
news items' stance and sentiment can be utilized to analyze and quantify the
extent to which recommender systems suffer from biases. To that end, we have
annotated a German news corpus on the topic of migration using stance detection
and sentiment analysis. In an experimental evaluation with four different
recommender systems, our results show a slight tendency of all four models for
recommending articles with negative sentiments and stances against the topic of
refugees and migration. Moreover, we observed a positive correlation between
the sentiment and stance bias of the text-based recommenders and the
preexisting user bias, which indicates that these systems amplify users'
opinions and decrease the diversity of recommended news. The knowledge-aware
model appears to be the least prone to such biases, at the cost of predictive
accuracy.Comment: Accepted at the 2nd International Workshop on Knowledge Graphs for
Online Discourse Analysis (KnOD 2022) collocated with The Web Conference 2022
(WWW'22), 25-29 April 2022, Lyon, Franc
Divided by the algorithm? The (limited) effects of content- and sentiment-based news recommendation on affective, ideological, and perceived polarization
Recent rises in political polarization across the globe are often ascribed to algorithmic content filtering on social media, news platforms, or search engines. The widespread usage of news recommendation systems (NRS) is theorized to drive users in homogenous information environments and, thereby, drive affective, ideological, and perceived polarization. To test this assumption, we conducted an online experiment (n = 750) with running algorithms that enriches content-based NRS with negative or neutral sentiment. Our experiment finds only limited evidence for polarization effects of content-based NRS. Nevertheless, the time spent with an NRS and its recommended articles seems to play a crucial role as a moderator of polarization. The longer participants were using an NRS enriched with negative sentiment, the more they got affectively polarized, whereas participants using an NRS incorporating balanced sentiment ideologically depolarized over time. Implications for future research are discussed
Dissipative Quantum Systems with Potential Barrier. General Theory and Parabolic Barrier
We study the real time dynamics of a quantum system with potential barrier
coupled to a heat-bath environment. Employing the path integral approach an
evolution equation for the time dependent density matrix is derived. The time
evolution is evaluated explicitly near the barrier top in the temperature
region where quantum effects become important. It is shown that there exists a
quasi-stationary state with a constant flux across the potential barrier. This
state generalizes the Kramers flux solution of the classical Fokker-Planck
equation to the quantum regime. In the temperature range explored the quantum
flux state depends only on the parabolic approximation of the anharmonic
barrier potential near the top. The parameter range within which the solution
is valid is investigated in detail. In particular, by matching the flux state
onto the equilibrium state on one side of the barrier we gain a condition on
the minimal damping strength. For very high temperatures this condition reduces
to a known result from classical rate theory. Within the specified parameter
range the decay rate out of a metastable state is calculated from the flux
solution. The rate is shown to coincide with the result of purely thermodynamic
methods. The real time approach presented can be extended to lower temperatures
and smaller damping.Comment: 29 pages + 1 figure as compressed ps-file (uufiles) to appear in
Phys. Rev.
Arterial bicarbonate is associated with hypoxic burden and uncontrolled hypertension in obstructive sleep apnea - The ESADA cohort
Objective: Blood bicarbonate concentration plays an important role for obstructive sleep apnea (OSA) patients to maintain acid-base balance. We investigated the association between arterial standard bicarbonate ([HCO3-]) and nocturnal hypoxia as well as comorbid hypertension in OSA. Methods: A cross-sectional analysis of 3329 patients in the European Sleep Apnea Database (ESADA) was performed. Arterial blood gas analysis and lung function test were performed in conjunction with polysomnographic sleep studies. The 4% oxygen desaturation index (ODI), mean and minimum oxygen saturation (SpO2), and percentage of time with SpO2 below 90% (T90%) were used to reflect nocturnal hypoxic burden. Arterial hypertension was defined as a physician diagnosis of hypertension with ongoing antihypertensive medication. Hypertensive patients with SBP/DBP below or above 140/90 mmHg were classified as controlled-, uncontrolled hypertension, respectively. Results: The [HCO3-] level was normal in most patients (average 24.0 ± 2.5 mmol/L). ODI, T90% increased whereas mean and minimum SpO2 decreased across [HCO3-] tertiles (ANOVA, p = 0.030, <0.001, <0.001, and <0.001, respectively). [HCO3-] was independently associated with ODI, mean SpO2, minimum SpO2, and T90% after adjusting for confounders (β value [95%CI]: 1.21 [0.88–1.54], −0.16 [-0.20 to −0.11], −0.51 [-0.64 to −0.37], 1.76 [1.48–2.04], respectively, all p < 0.001). 1 mmol/L elevation of [HCO3-] was associated with a 4% increased odds of uncontrolled hypertension (OR: 1.04 [1.01–1.08], p = 0.013). Conclusion: We first demonstrated an independent association between [HCO3-] and nocturnal hypoxic burden as well as uncontrolled hypertension in OSA patients. Bicarbonate levels as an adjunctive measure provide insight into the pathophysiology of hypertension in OSA
Erythropoiesis-stimulating agents in oncology: a study-level meta-analysis of survival and other safety outcomes
BACKGROUND: Cancer patients often develop the potentially debilitating condition of anaemia. Numerous controlled studies indicate that erythropoiesis-stimulating agents (ESAs) can raise haemoglobin levels and reduce transfusion requirements in anaemic cancer patients receiving chemotherapy. To evaluate recent safety concerns regarding ESAs, we carried out a meta-analysis of controlled ESA oncology trials to examine whether ESA use affects survival, disease progression and risk of venous-thromboembolic events
Biological exposure assessment to tetrachloroethylene for workers in the dry cleaning industry
Rare variants in BNC2 are implicated in autosomal-dominant congenital lower urinary-tract obstruction
Congenital lower urinary-tract obstruction (LUTO) is caused by anatomical blockage of the bladder outflow tract or by functional impairment of urinary voiding. About three out of 10,000 pregnancies are affected. Although several monogenic causes of functional obstruction have been defined, it is unknown whether congenital LUTO caused by anatomical blockage has a monogenic cause. Exome sequencing in a family with four affected individuals with anatomical blockage of the urethra identified a rare nonsense variant (c.2557C>T [p.Arg853(∗)]) in BNC2, encoding basonuclin 2, tracking with LUTO over three generations. Re-sequencing BNC2 in 697 individuals with LUTO revealed three further independent missense variants in three unrelated families. In human and mouse embryogenesis, basonuclin 2 was detected in lower urinary-tract rudiments. In zebrafish embryos, bnc2 was expressed in the pronephric duct and cloaca, analogs of the mammalian lower urinary tract. Experimental knockdown of Bnc2 in zebrafish caused pronephric-outlet obstruction and cloacal dilatation, phenocopying human congenital LUTO. Collectively, these results support the conclusion that variants in BNC2 are strongly implicated in LUTO etiology as a result of anatomical blockage
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