141 research outputs found
Trust and Bias in Peer-to-Peer Ratings: Why Peer-to-Peer Service Ratings are Nearly Always Positive, and How They Can be Fixed
Transactions in the peer-to-peer sharing economy carry high risk and uncertainty. Consumers exchange with non-professional providers with whom they have no past history, and must rely on ratings and reviews for choice selection. However, there is a large positive bias in the ratings, making differentiation difficult, and causing some consumers to lose trust. Despite these concerns, little progress has been made to demonstrate the cause of the bias or how it can be fixed. I address this gap by demonstrating that consumers evaluate peer-peer experiences based on trust. This trust evaluation, in concert with network and social factors, contributes to the bias.
Research on service evaluation is often informed by the expectancy disconfirmation process (Oliver, 1980, 2010). Consumers compare a provider’s performance against prior expectations; the resultant satisfaction or dissatisfaction leads to online ratings. I demonstrate that the process works differently for peer-to-peer services; a consumer’s determination of whether a provider met expectations has an effect on ratings beyond the effect of satisfaction (Study 1). When uncertainty and risk are high, a provider demonstrates that they can be trusted by meeting a consumer’s prior expectations (Study 2). Contextual factors in peer-to-peer networks cause consumers to feel that their ratings are more important to peer providers, and that they may need to justify ratings. This elevates trust as an important driver of ratings at the expense of satisfaction, because satisfaction is more subjective and more difficult to justify (Study 3).
Consumers may give peer providers positive ratings even if performance is worse than expected. Standards of evaluation are relatively unclear for peer-to-peer services (making it more difficult to identify performance failure), and social norms of gratitude and empathy motivate consumers to forgive peer providers for unreliable service (Studies 4 and 5). Negative ratings for peer providers may result only if consumers believe that a provider caused and controlled a negative outcome, which suggests a lack of integrity (Study 6). I demonstrate that platforms can attenuate the positive bias by making ratings anonymous, by clearly defining service standards, and by increasing perceived controllability by providers for expectations and performance failure
Infrared images of reflection nebulae and Orion's bar: Fluorescent molecular hydrogen and the 3.3 micron feature
Images were obtained of the (fluorescent) molecular hydrogen 1-0 S(1) line, and of the 3.3 micron emission feature, in Orion's Bar and three reflection nebulae. The emission from these species appears to come from the same spatial locations in all sources observed. This suggests that the 3.3 micron feature is excited by the same energetic UV-photons which cause the molecular hydrogen to fluoresce
The GLOBE-Consortium: The Next-Generation Genome Viewer
The GLOBE 3D Genome Viewer is the novel system-biology oriented genome browser necessary to access,
present, annotate, and to simulate the holistic genome complexity in a unique gateway towards a real
understanding, educative presentation and curative manipulation planning of this tremendous evolutionary
information grail – genomes. This has required completely new approaches to represent the genome architecture
realistically in combination with the various types of informational annotation including experimental data or
instant analysis capabilities. This creates unrivalled new opportunities for scientific researchers, diagnostic users,
educators and publishers as well as PR and commercial applicants. Potential BETA-TESTERS of the GLOBE 3D
Genome Viewer are asked to sign up now
G3DV: A new 3D genome browser and experimental data viewer.
Genomes are tremendous co-evolutionary holistic systems for molecular storage, processing and fabrication of
information. Their system-biological complexity remains, however, still largely mysterious, despite immense
sequencing achievements and huge advances in the understanding of the general sequential, three-dimensional
and regulatory organization. Here, we present the GLOBE 3D Genome Platform a completely novel grid based
virtual “paper” tool and in fact the first system-biological genome browser integrating the holistic complexity of
genomes in a single easy comprehensible platform: Based on a detailed study of biophysical and IT
requirements, every architectural level from sequence to morphology of one or several genomes can be
approached in a real and in a symbolic representation simultaneously and navigated by continuous scale-free
zooming within a unique three-dimensional OpenGL and grid driven environment. In principle an unlimited
number of multi-dimensional data sets can be visualized, customized in terms of arrangement, shape, colour, and
texture etc. as well as accessed and annotated individually or in groups using internal or external data
bases/facilities. Any information can be searched and correlated by importing or calculating simple relations in
real-time using grid resources. A general correlation and application platform for more complex correlative
analysis and a front-end for system-biological simulations both using again the huge capabilities of grid
infrastructures is currently under development. Hence, the GLOBE 3D Genome Platform is an example of a grid
based approach towards a virtual desktop for genomic work combining the three fundamental distributed
resources: i) visual data representation, ii) data access and management, and iii) data analysis and creation. Thus,
the GLOBE 3D Genome Platform is the novel system-biology oriented information system urgently needed to
access, present, annotate, and to simulate the holistic genome complexity in a unique gateway towards a real
understanding, educative presentation and curative manipulation planning of this tremendous evolutionary
information grail – genomes
TF Target Mapper: A BLAST search tool for the identification of Transcription Factor target genes
BACKGROUND: In the current era of high throughput genomics a major challenge is the genome-wide identification of target genes for specific transcription factors. Chromatin immunoprecipitation (ChIP) allows the isolation of in vivo binding sites of transcription factors and provides a powerful tool for examining gene regulation. Crosslinked chromatin is immunoprecipitated with antibodies against specific transcription factors, thus enriching for sequences bound in vivo by these factors in the immunoprecipitated DNA. Cloning and sequencing the immunoprecipitated sequences allows identification of transcription factor target genes. Routinely, thousands of such sequenced clones are used in BLAST searches to map their exact location in the genome and the genes located in the vicinity. These genes represent potential targets of the transcription factor of interest. Such bioinformatics analysis is very laborious if performed manually and for this reason there is a need for developing bioinformatic tools to automate and facilitate it. RESULTS: In order to facilitate this analysis we generated TF Target Mapper (Transcription Factor Target Mapper). TF Target Mapper is a BLAST search tool allowing rapid extraction of annotated information on genes around each hit. It combines sequence cleaning/filtering, pattern searching and BLAST searches with extraction of information on genes located around each BLAST hit and comparisons of the output list of genes or gene ontology IDs with user-implemented lists. We successfully applied and tested TF Target Mapper to analyse sequences bound in vivo by the transcription factor GATA-1. We show that TF Target Mapper efficiently extracted information on genes around ChIPed sequences, thus identifying known (e.g. α-globin and ζ-globin) and potentially novel GATA-1 gene targets. CONCLUSION: TF Target Mapper is a very efficient BLAST search tool that allows the rapid extraction of annotated information on the genes around each hit. It can contribute to the comprehensive bioinformatic transcriptome/regulome analysis, by providing insight into the mechanisms of action of specific transcription factors, thus helping to elucidate the pathways these factors regulate
The Auld Enemy? Exploring the England vs. Scotland rivalry from the perspective of soccer fans
A longstanding and persistent rivalry is said to exist between England and Scotland in the context of international soccer. In this essay we seek to test common media representations emphasising division against the opinions of English and Scottish soccer fans themselves. The complexity of English views towards Scottish people both inside and outside of soccer is explored using examples from an online participant observation study with English fans. Moreover, the extent to which anti-English sentiment constitutes an element of Scottish national identity in soccer and society more broadly is also explored using examples from semi-structured interviews with Scottish fans on the topic of the rivalry between the two nations. We argue that via representations in the media soccer has both provided the context for reinforcing broader divisions between these neighbouring nations as well as creating specific memories in the minds of soccer fans that enhance divisive feelings amongst some English and Scottish fans. However, we also note the extent to which the stereotype of division is perpetuated by the media and how this is sometimes at odds with the views of both Scottish and English fans alike. We conclude that so long as the media perpetuate division between the two nations in a simplistic manner the reality of the complex and evolving relationship between Scottish and English fans will remain unclear and misunderstood
Infrared Studies of Molecular Shocks in the Supernova Remnant HB21: I. Thermal Admixture of Shocked H_2 Gas in the North
We present near- and mid-infrared observations on the shock-cloud interaction
region in the northern part of the supernova remnant HB21, performed with the
InfraRed Camera (IRC) aboard AKARI satellite and the Wide InfraRed Camera
(WIRC) at the Palomar 5 m telescope. The IRC 7 um (S7), 11 um (S11), and 15 um
(L15) band images and the WIRC H2 v = 1 -> 0 S(1) 2.12 um image show similar
shock-cloud interaction features. We chose three representative regions, and
analyzed their IRC emissions through comparison with H2 line emissions of
several shock models. The IRC colors are well explained by the thermal
admixture model of H2 gas--whose infinitesimal H2 column density has a
power-law relation with the temperature T, dN ~ T^-b dT--with n(H2) ~ 10^3
cm^-3, b ~ 3, and N(H2 ;T > 100K) ~ 3x10^20 cm^-2. The derived b value may be
understood by a bow shock picture, whose shape is cycloidal (cuspy) rather than
paraboloidal. However, this picture raises another issue that the bow shocks
must reside within ~0.01 pc size-scale, smaller than the theoretically
expected. Instead, we conjectured a shocked clumpy interstellar medium picture,
which may avoid the sizescale issue while explaining the similar model
parameters. The observed H2 v = 1 -> 0 S(1) intensities are a factor of ~17 -
33 greater than the prediction from the power-law admixture model. This excess
may be attributed to either an extra component of hot H2 gas or to the effects
of collisions with hydrogen atoms, omitted in our power-law admixture model,
both of which would increase the population in the v = 1 level of H2.Comment: 14 pages, 9 figures, ApJ accepted, higher resolution @
http://astro.snu.ac.kr/~jhshinn/ms.pd
ImmunoGlobulin galaxy (IGGalaxy) for simple determination and quantitation of immunoglobulin heavy chain rearrangements from NGS
Background: Sequence analysis of immunoglobulin heavy chain (IGH) gene rearrangements and frequency analysis is a powerful tool for studying the immune repertoire, immune responses and immune dysregulation in health and disease. The challenge is to provide user friendly, secure and reproducible analytical services that are available for both small and large laboratories which are determining VDJ repertoire using NGS technology. Results: In this study we describe ImmunoGlobulin Galaxy (IGGalaxy)- a convenient web based application for analyzing next-generation sequencing results and reporting IGH gene rearrangements for both repertoire and clonality studies. IGGalaxy has two analysis options one using the built in igBLAST algorithm and the second using output from IMGT; in either case repertoire summaries for the B-cell populations tested are available. IGGalaxy supports multi-sample and multi-replicate input analysis for both igBLAST and IMGT/HIGHV-QUEST. We demonstrate the technical validity of this platform using a standard dataset, S22, used for benchmarking the performance of antibody alignment utilities with a 99.9 % concordance with previous results. Re-analysis of NGS data from our samples of RAG-deficient patients demonstrated the validity and user friendliness of this tool. Conclusions: IGGalaxy provides clinical researchers with detailed insight into the repertoire of the B-cell population per individual sequenced and between control and pathogenic genomes. IGGalaxy was developed for 454 NGS results but is capable of analyzing alternative NGS data (e.g. Illumina, Ion Torrent). We demonstrate the use of a Galaxy virtual machine to determine the VDJ repertoire for reference data and from B-cells taken from immune deficient patients. IGGalaxy is available as a VM for download and use on a desktop PC or on a server
Infrared Studies of Molecular Shocks in the Supernova Remnant HB 21: II. Thermal Admixture of Shocked H Gas in the South
We present near- and mid-infrared observations on the shock-cloud interaction
region in the southern part of the supernova remnant HB 21, performed with the
InfraRed Camera (IRC) aboard AKARI satellite and the Wide InfraRed Camera
(WIRC) at the Palomar 5 m telescope. The IRC 4 um (N4), 7 um (S7), and 11 um
(S11) band images and the WIRC H2 v=1->0 S(1) 2.12 um image show similar
diffuse features, around a shocked CO cloud. We analyzed the emission through
comparison with the H2 line emission of several shock models. The IRC colors
are well explained by the thermal admixture model of H2 gas--whose
infinitesimal H2 column density has a power-law relation with the temperature
, --with n(H2) cm^{-2}, , and
N(H2;T>100K) cm^{-2}. We interpreted these parameters
with several different pictures of the shock-cloud interactions--multiple
planar C-shocks, bow shocks, and shocked clumps--and discuss their weaknesses
and strengths. The observed H2 v=1->0 S(1) intensity is four times greater than
the prediction from the power-law admixture model, the same tendency as found
in the northern part of HB 21 (Paper I). We also explored the limitation of the
thermal admixture model with respect to the derived model parameters.Comment: 35 pages, 10 figures, Accepted in "Advances in Space Research",
higher resolution @
http://astro.snu.ac.kr/~jhshinn/asr-20090921-submitted_arxiv.pdf ; rev.2 -
deletion of section 6.4 and the related content
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