1,887 research outputs found
The Effects of Flagging Propaganda Sources on News Sharing:Quasi-Experimental Evidence from Twitter
While research on flagging misinformation and disinformation has received much attention, we know very little about how the flagging of propaganda sources could affect news sharing on social media. Using a quasi-experimental design, we test the effect of source flagging on people’s actual sharing behaviors. By analyzing tweets (N = 49,126) posted by 30 China's media accounts before and after Twitter's practice of labeling state-affiliated media, we reveal the corrective role that flagging plays in preventing people's sharing of information from propaganda sources. The findings suggest that the corrective effect occurs immediately after these accounts are labeled as state-affiliated media and it leads to a long-term reduction in news sharing, particularly for political content. The results contribute to the understanding of how flagging efforts affect user engagement in real-world conversations and highlight that the effect of corrective measures takes place in a dynamic process
Remanufacturing strategies : a solution for WEEE problem
The electrical and electronic equipment (EEE) industry has increased its mass production; however, the EEE life span has similarly diminished. Owing to the rapid expansion of manufacturing, innovation and consumer demand, there has been a vast improvement in various electronic equipment, so the amount of waste electrical and electronic equipment (WEEE, or e-waste) generated has also increased proportionally to production. The main objective of this article is to evaluate the remanufacturing concept which can be adopt by the electronic manufacturing industry. The article reveals differential steps debated by industry as well as academia in assets to reduce the amount of e-waste. The concept of e-waste remanufacturing is quite dissimilar from case studies among developing and developed countries and regions. The findings can assist the academic research and leads to industry regardless remanufacturing of used EEE or WEEE by exemplifying different methods and ideologies of remanufacturing implementation plus the main issues in this field
Americans’ Attitudes toward the Affordable Care Act: What Role Do Beliefs Play?
How do people form their attitudes toward complex policy issues? Although there has long been an assumption that people consider the various components of those issues and come to an overall assessment, a growing body of recent work has instead suggested that people may reach summary judgments as a function of heuristic cues and goal-oriented rationalizations. This study examines how well a component-based model fits Americans’ evaluations of the Patient Protection and Affordable Care Act of 2010, an important and highly contentious piece of legislation that contained several constituent parts. Despite strong partisan disagreement about the law, we find that Democrats and Republicans both appear to evaluate the law as a function of their beliefs and what the law would do as well as their confidence in those beliefs. This finding implies that correcting misperceptions and increasing awareness of the components of legislation have the potential to change attitudes
Theory and phenomenology of two-Higgs-doublet models
We discuss theoretical and phenomenological aspects of two-Higgs-doublet
extensions of the Standard Model. In general, these extensions have scalar
mediated flavour changing neutral currents which are strongly constrained by
experiment. Various strategies are discussed to control these flavour changing
scalar currents and their phenomenological consequences are analysed. In
particular, scenarios with natural flavour conservation are investigated,
including the so-called type I and type II models as well as lepton-specific
and inert models. Type III models are then discussed, where scalar flavour
changing neutral currents are present at tree level, but are suppressed by
either specific ansatze for the Yukawa couplings or by the introduction of
family symmetries. We also consider the phenomenology of charged scalars in
these models. Next we turn to the role of symmetries in the scalar sector. We
discuss the six symmetry-constrained scalar potentials and their extension into
the fermion sector. The vacuum structure of the scalar potential is analysed,
including a study of the vacuum stability conditions on the potential and its
renormalization-group improvement. The stability of the tree level minimum of
the scalar potential in connection with electric charge conservation and its
behaviour under CP is analysed. The question of CP violation is addressed in
detail, including the cases of explicit CP violation and spontaneous CP
violation. We present a detailed study of weak basis invariants which are odd
under CP. A careful study of spontaneous CP violation is presented, including
an analysis of the conditions which have to be satisfied in order for a vacuum
to violate CP. We present minimal models of CP violation where the vacuum phase
is sufficient to generate a complex CKM matrix, which is at present a
requirement for any realistic model of spontaneous CP violation.Comment: v3: 180 pages, 506 references, new chapter 7 with recent LHC results;
referee comments taken into account; submitted to Physics Report
RET Mutational Spectrum in Hirschsprung Disease: Evaluation of 601 Chinese Patients
Rare (RVs) and common variants of the RET gene contribute to Hirschsprung disease (HSCR; congenital aganglionosis). While RET common variants are strongly associated with the commonest manifestation of the disease (males; short-segment aganglionosis; sporadic), rare coding sequence (CDS) variants are more frequently found in the lesser common and more severe forms of the disease (females; long/total colonic aganglionosis; familial)
The Liver Tumor Segmentation Benchmark (LiTS)
In this work, we report the set-up and results of the Liver Tumor
Segmentation Benchmark (LITS) organized in conjunction with the IEEE
International Symposium on Biomedical Imaging (ISBI) 2016 and International
Conference On Medical Image Computing Computer Assisted Intervention (MICCAI)
2017. Twenty four valid state-of-the-art liver and liver tumor segmentation
algorithms were applied to a set of 131 computed tomography (CT) volumes with
different types of tumor contrast levels (hyper-/hypo-intense), abnormalities
in tissues (metastasectomie) size and varying amount of lesions. The submitted
algorithms have been tested on 70 undisclosed volumes. The dataset is created
in collaboration with seven hospitals and research institutions and manually
reviewed by independent three radiologists. We found that not a single
algorithm performed best for liver and tumors. The best liver segmentation
algorithm achieved a Dice score of 0.96(MICCAI) whereas for tumor segmentation
the best algorithm evaluated at 0.67(ISBI) and 0.70(MICCAI). The LITS image
data and manual annotations continue to be publicly available through an online
evaluation system as an ongoing benchmarking resource.Comment: conferenc
Astro2020 APC White Paper: The Early Career Perspective on the Coming Decade, Astrophysics Career Paths, and the Decadal Survey Process
In response to the need for the Astro2020 Decadal Survey to explicitly engage
early career astronomers, the National Academies of Sciences, Engineering, and
Medicine hosted the Early Career Astronomer and Astrophysicist Focus Session
(ECFS) on October 8-9, 2018 under the auspices of Committee of Astronomy and
Astrophysics. The meeting was attended by fifty six pre-tenure faculty,
research scientists, postdoctoral scholars, and senior graduate students, as
well as eight former decadal survey committee members, who acted as
facilitators. The event was designed to educate early career astronomers about
the decadal survey process, to solicit their feedback on the role that early
career astronomers should play in Astro2020, and to provide a forum for the
discussion of a wide range of topics regarding the astrophysics career path.
This white paper presents highlights and themes that emerged during two days
of discussion. In Section 1, we discuss concerns that emerged regarding the
coming decade and the astrophysics career path, as well as specific
recommendations from participants regarding how to address them. We have
organized these concerns and suggestions into five broad themes. These include
(sequentially): (1) adequately training astronomers in the statistical and
computational techniques necessary in an era of "big data", (2) responses to
the growth of collaborations and telescopes, (3) concerns about the adequacy of
graduate and postdoctoral training, (4) the need for improvements in equity and
inclusion in astronomy, and (5) smoothing and facilitating transitions between
early career stages. Section 2 is focused on ideas regarding the decadal survey
itself, including: incorporating early career voices, ensuring diverse input
from a variety of stakeholders, and successfully and broadly disseminating the
results of the survey
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Degradation aspects of water formation and transport in Proton Exchange Membrane Fuel Cell: A review
This review paper summarises the key aspects of Proton Exchange Membrane Fuel Cell (PEMFC) degradation that are associated with water formation, retention, accumulation, and transport mechanisms within the cell. Issues related to loss of active surface area of the catalyst, ionomer dissolution, membrane swelling, ice formation, corrosion, and contamination are also addressed and discussed. The impact of each of these water mechanisms on cell performance and durability was found to be different and to vary according to the design of the cell and its operating conditions. For example, the presence of liquid water within Membrane Electrode Assembly (MEA), as a result of water accumulation, can be detrimental if the operating temperature of the cell drops to sub-freezing. The volume expansion of liquid water due to ice formation can damage the morphology of different parts of the cell and may shorten its life-time. This can be more serious, for example, during the water transport mechanism where migration of Pt particles from the catalyst may take place after detachment from the carbon support. Furthermore, the effect of transport mechanism could be augmented if humid reactant gases containing impurities poison the membrane, leading to the same outcome as water retention or accumulation.
Overall, the impact of water mechanisms can be classified as aging or catastrophic. Aging has a long-term impact over the duration of the PEMFC life-time whereas in the catastrophic mechanism the impact is immediate. The conversion of cell residual water into ice at sub-freezing temperatures by the water retention/ accumulation mechanism and the access of poisoning contaminants through the water transport mechanism are considered to fall into the catastrophic category. The effect of water mechanisms on PEMFC degradation can be reduced or even eliminated by (a) using advanced materials for improving the electrical, chemical and mechanical stability of the cell components against deterioration, and (b) implementing effective strategies for water management in the cell
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
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