208 research outputs found
Data Portraits and Intermediary Topics: Encouraging Exploration of Politically Diverse Profiles
In micro-blogging platforms, people connect and interact with others.
However, due to cognitive biases, they tend to interact with like-minded people
and read agreeable information only. Many efforts to make people connect with
those who think differently have not worked well. In this paper, we
hypothesize, first, that previous approaches have not worked because they have
been direct -- they have tried to explicitly connect people with those having
opposing views on sensitive issues. Second, that neither recommendation or
presentation of information by themselves are enough to encourage behavioral
change. We propose a platform that mixes a recommender algorithm and a
visualization-based user interface to explore recommendations. It recommends
politically diverse profiles in terms of distance of latent topics, and
displays those recommendations in a visual representation of each user's
personal content. We performed an "in the wild" evaluation of this platform,
and found that people explored more recommendations when using a biased
algorithm instead of ours. In line with our hypothesis, we also found that the
mixture of our recommender algorithm and our user interface, allowed
politically interested users to exhibit an unbiased exploration of the
recommended profiles. Finally, our results contribute insights in two aspects:
first, which individual differences are important when designing platforms
aimed at behavioral change; and second, which algorithms and user interfaces
should be mixed to help users avoid cognitive mechanisms that lead to biased
behavior.Comment: 12 pages, 7 figures. To be presented at ACM Intelligent User
Interfaces 201
Discovering Polarized Communities in Signed Networks
Signed networks contain edge annotations to indicate whether each interaction
is friendly (positive edge) or antagonistic (negative edge). The model is
simple but powerful and it can capture novel and interesting structural
properties of real-world phenomena. The analysis of signed networks has many
applications from modeling discussions in social media, to mining user reviews,
and to recommending products in e-commerce sites. In this paper we consider the
problem of discovering polarized communities in signed networks. In particular,
we search for two communities (subsets of the network vertices) where within
communities there are mostly positive edges while across communities there are
mostly negative edges. We formulate this novel problem as a "discrete
eigenvector" problem, which we show to be NP-hard. We then develop two
intuitive spectral algorithms: one deterministic, and one randomized with
quality guarantee (where is the number of vertices in the
graph), tight up to constant factors. We validate our algorithms against
non-trivial baselines on real-world signed networks. Our experiments confirm
that our algorithms produce higher quality solutions, are much faster and can
scale to much larger networks than the baselines, and are able to detect
ground-truth polarized communities
Host-interactor screens of Phytophthora infestans RXLR proteins reveal vesicle trafficking as a major effector-targeted process
Pathogens modulate plant cell structure and function by secreting effectors into host tissues. Effectors typically function by associating with host molecules and modulating their activities. This study aimed to identify the host processes targeted by the RXLR class of host-translocated effectors of the potato blight pathogen Phytophthora infestans. To this end, we performed an in planta protein-protein interaction screen by transiently expressing P. infestans RXLR effectors in Nicotiana benthamiana leaves followed by co-immunoprecipitation and liquid chromatography tandem mass spectrometry. This screen generated an effector-host protein interactome matrix of 59 P. infestans RXLR effectors x 586 N. benthamiana proteins. Classification of the host interactors into putative functional categories revealed over 35 biological processes possibly targeted by P. infestans. We further characterized the PexRD12/31 family of RXLR-WY effectors, which associate and co-localize with components of the vesicle trafficking machinery. One member of this family, PexRD31, increased the number of FYVE positive vesicles in N. benthamiana cells. FYVE positive vesicles also accumulated in leaf cells near P. infestans hyphae, indicating that the pathogen may enhance endosomal trafficking during infection. This interactome data set will serve as a useful resource for functional studies of P. infestans effectors and of effector-targeted host processes
Full wafer integration of NEMS on CMOS by nanostencil lithography
Wafer scale nanostencil lithography is used to define 200 nm scale mechanically resonating silicon cantilevers monolithically integrated into CMOS circuits. We demonstrate the simultaneous patterning of ~2000 nanodevices by post-processing standard CMOS wafers using one single metal evaporation, pattern transfer to silicon and subsequent etch of the sacrificial layer. Resonance frequencies around 1.5 MHz were measured in air and vacuum and tuned by applying dc voltages of 10V and 1V respectively.LMIS
Vascular Endothelial Growth Factor Mediates Intracrine Survival in Human Breast Carcinoma Cells through Internally Expressed VEGFR1/FLT1
Shalom Avraham and colleagues' study provides evidence of a survival system in breast cancer cells by which VEGF acts as an internal autocrine survival factor through its binding to VEGFR1
SARS-CoV-2 Catalonia contact tracing program : evaluation of key performance indicators
Background: Guidance on SARS-CoV-2 contact tracing indicators have been recently revised by international public health agencies. The aim of the study is to describe and analyse contact tracing indicators based on Catalonia's (Spain) real data and proposing to update them according to recommendations. Methods: Retrospective cohort analysis including Catalonia's contact tracing dataset from 20 May until 31 December 2020. Descriptive statistics are performed including sociodemographic stratification by age, and differences are assessed over the study period. Results: We analysed 923,072 contacts from 301,522 SARS-CoV-2 cases with identified contacts (67.1% contact tracing coverage). The average number of contacts per case was 4.6 (median 3, range 1-243). A total of 403,377 contacts accepted follow-up through three phone calls over a 14-day quarantine period (84.5% of contacts requiring follow-up). The percentage of new cases declared as contacts 14 days prior to diagnosis evolved from 33.9% in May to 57.9% in November. All indicators significantly improved towards the target over time (p < 0.05 for all four indicators). Conclusions: Catalonia's SARS-CoV-2 contact tracing indicators improved over time despite challenging context. The critical revision of the indicator's framework aims to provide essential information in control policies, new indicators proposed will improve system delay's follow-up. The study provides information on COVID-19 indicators framework experience from country's real data, allowing to improve monitoring tools in 2021-2022. With the SARS-CoV-2 pandemic being so harmful to health systems and globally, is important to analyse and share contact tracing data with the scientific community
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