2,704 research outputs found
The Effects of Personalized Recommendations with Popularity Information on Sales - A Field Study in Grocery Retailing
In consumer and information systems research, it remains unclear how consumers consider smartphone app recommendations in the course of their decision making process that leads to product choices in the physical store. Moreover, it is unclear which type of information smartphone apps should transport to consumers and if there are any customer segmentation criteria for smartphone app design. With respect to the theoretical and managerial importance of recommendation services in the form of smartphone apps we want to shed some light on this topic. Combining literature from the fields of IS and marketing research, we hypothesize that personalized recommendations via smartphone apps can help to boost sales in physical grocery stores. Furthermore, we hypothesize that additional popularity information (in the form of âstarsâ) does not amplify the positive effect of personalized recommendations. In addition, we assume that the effects of recommendation usage differ for men and women. We conducted a field study with a European grocery retailer to test our hypotheses. Finally, we discuss first implications as well as central limitations of our research and present the next research steps
A Spitzer Space Telescope far-infrared spectral atlas of compact sources in the Magellanic Clouds. II. The Small Magellanic Cloud
We present 52-93 micron spectra, obtained with the Spitzer Space Telescope,
of luminous compact far-IR sources in the SMC. These comprise 9 Young Stellar
Objects (YSOs), the compact HII region N81 and a similar object within N84, and
two red supergiants (RSGs). The spectra of the sources in N81 (of which we also
show the ISO-LWS spectrum between 50-170 micron) and N84 both display strong
[OI] 63-micron and [OIII] 88-micron fine-structure line emission. We attribute
these lines to strong shocks and photo-ionized gas, respectively, in a
``champagne flow'' scenario. The nitrogen content of these two HII regions is
very low, definitely N/O<0.04 but possibly as low as N/O<0.01. Overall, the
oxygen lines and dust continuum are weaker in star-forming objects in the SMC
than in the LMC. We attribute this to the lower metallicity of the SMC compared
to that of the LMC. Whilst the dust mass differs in proportion to metallicity,
the oxygen mass differs less; both observations can be reconciled with higher
densities inside star-forming cloud cores in the SMC than in the LMC. The dust
in the YSOs in the SMC is warmer (37-51 K) than in comparable objects in the
LMC (32-44 K). We attribute this to the reduced shielding and reduced cooling
at the low metallicity of the SMC. On the other hand, the efficiency of the
photo-electric effect to heat the gas is found to be indistinguishable to that
measured in the same manner in the LMC, 0.1-0.3%. This may result from higher
cloud-core densities, or smaller grains, in the SMC. The dust associated with
the two RSGs in our SMC sample is cool, and we argue that it is swept-up
interstellar dust, or formed (or grew) within the bow-shock, rather than dust
produced in these metal-poor RSGs themselves. Strong emission from crystalline
water ice is detected in at least one YSO. (abridged)Comment: Accepted for publication in The Astronomical Journa
Escherichia coli induces apoptosis and proliferation of mammary cells
Mammary cell apoptosis and proliferation were assessed after injection of Escherichia coli into the left mammary quarters of six cows. Bacteriological analysis of foremilk samples revealed coliform infection in the injected quarters of four cows. Milk somatic cell counts increased in these quarters and peaked at 24 h after bacterial injection. Body temperature also increased, peaking at 12 h postinjection, The number of apoptotic cells was significantly higher in the mastitic tissue than in the uninfected control. Expression of Bax and interleukin-1 beta converting enzyme increased in the mastitic tissue at 24 h and 72 h postinfection, whereas Bcl-2 expression decreased at 24 h but did not differ significantly from the control at 72 h postinfection, Induction of matrix metalloproteinase-g, stromelysin-1 and urokinase-type plasminogen activator was also observed in the mastitic tissue. Moreover, cell proliferation increased in the infected tissue, These results demonstrate that Escherichia coli-induced mastitis promotes apoptosis and cell proliferation
Deweyan tools for inquiry and the epistemological context of critical pedagogy
This article develops the notion of resistance as articulated in the literature of critical pedagogy as being both culturally sponsored and cognitively manifested. To do so, the authors draw upon John Dewey\u27s conception of tools for inquiry. Dewey provides a way to conceptualize student resistance not as a form of willful disputation, but instead as a function of socialization into cultural models of thought that actively truncate inquiry. In other words, resistance can be construed as the cognitive and emotive dimensions of the ongoing failure of institutions to provide ideas that help individuals both recognize social problems and imagine possible solutions. Focusing on Dewey\u27s epistemological framework, specifically tools for inquiry, provides a way to grasp this problem. It also affords some innovative solutions; for instance, it helps conceive of possible links between the regular curriculum and the study of specific social justice issues, a relationship that is often under-examined. The aims of critical pedagogy depend upon students developing dexterity with the conceptual tools they use to make meaning of the evidence they confront; these are background skills that the regular curriculum can be made to serve even outside social justice-focused curricula. Furthermore, the article concludes that because such inquiry involves the exploration and potential revision of students\u27 world-ordering beliefs, developing flexibility in how one thinks may be better achieved within academic subjects and topics that are not so intimately connected to students\u27 current social lives, especially where students may be directly implicated
Search for the exotic Resonance in 340GeV/c -Nucleus Interactions
We report on a high statistics search for the resonance in
-nucleus collisions at 340GeV/c. No evidence for this resonance is
found in our data sample which contains 676000 candidates above
background. For the decay channel and the
kinematic range 0.150.9 we find a 3 upper limit for the
production cross section of 3.1 and 3.5 b per nucleon for reactions with
carbon and copper, respectively.Comment: 5 pages, 4 figures, modification of ref. 43 and 4
JSBML 1.0: providing a smorgasbord of options to encode systems biology models
JSBML, the official pure Java programming library for the SBML format, has evolved with the advent of different modeling formalisms in systems biology and their ability to be exchanged and represented via extensions of SBML. JSBML has matured into a major, active open-source project with contributions from a growing, international team of developers who not only maintain compatibility with SBML, but also drive steady improvements to the Java interface and promote ease-of-use with end users
How Gibbs distributions may naturally arise from synaptic adaptation mechanisms. A model-based argumentation
This paper addresses two questions in the context of neuronal networks
dynamics, using methods from dynamical systems theory and statistical physics:
(i) How to characterize the statistical properties of sequences of action
potentials ("spike trains") produced by neuronal networks ? and; (ii) what are
the effects of synaptic plasticity on these statistics ? We introduce a
framework in which spike trains are associated to a coding of membrane
potential trajectories, and actually, constitute a symbolic coding in important
explicit examples (the so-called gIF models). On this basis, we use the
thermodynamic formalism from ergodic theory to show how Gibbs distributions are
natural probability measures to describe the statistics of spike trains, given
the empirical averages of prescribed quantities. As a second result, we show
that Gibbs distributions naturally arise when considering "slow" synaptic
plasticity rules where the characteristic time for synapse adaptation is quite
longer than the characteristic time for neurons dynamics.Comment: 39 pages, 3 figure
A Spitzer Space Telescope far-infrared spectral atlas of compact sources in the Magellanic Clouds. I. The Large Magellanic Cloud
[abridged] We present 52-93 micron spectra obtained with Spitzer in the
MIPS-SED mode, of a representative sample of luminous compact far-IR sources in
the LMC. These include carbon stars, OH/IR AGB stars, post-AGB objects and PNe,
RCrB-type star HV2671, OH/IR red supergiants WOHG064 and IRAS05280-6910, B[e]
stars IRAS04530-6916, R66 and R126, Wolf-Rayet star Brey3a, Luminous Blue
Variable R71, supernova remnant N49, a large number of young stellar objects,
compact HII regions and molecular cores, and a background galaxy (z~0.175). We
use the spectra to constrain the presence and temperature of cold dust and the
excitation conditions and shocks within the neutral and ionized gas, in the
circumstellar environments and interfaces with the surrounding ISM. Evolved
stars, including LBV R71, lack cold dust except in some cases where we argue
that this is swept-up ISM. This leads to an estimate of the duration of the
prolific dust-producing phase ("superwind") of several thousand years for both
RSGs and massive AGB stars, with a similar fractional mass loss experienced
despite the different masses. We tentatively detect line emission from neutral
oxygen in the extreme RSG WOHG064, with implications for the wind driving. In
N49, the shock between the supernova ejecta and ISM is revealed by its strong
[OI] 63-micron emission and possibly water vapour; we estimate that 0.2 Msun of
ISM dust was swept up. Some of the compact HII regions display pronounced
[OIII] 88-micron emission. The efficiency of photo-electric heating in the
interfaces of ionized gas and molecular clouds is estimated at 0.1-0.3%. We
confirm earlier indications of a low nitrogen content in the LMC. Evidence for
solid state emission features is found in both young and evolved object; some
of the YSOs are found to contain crystalline water ice.Comment: Accepted for publication in The Astronomical Journal. This paper
accompanies the Summer 2009 SAGE-Spec release of 48 MIPS-SED spectra, but
uses improved spectrum extraction. (Fig. 2 reduced resolution because of
arXiv limit.
High-sensitivity troponin assays for the early rule-out or diagnosis of acute myocardial infarction in people with acute chest pain: a systematic review and cost-effectiveness analysis.
BACKGROUND: Early diagnosis of acute myocardial infarction (AMI) can ensure quick and effective treatment but only 20% of adults with emergency admissions for chest pain have an AMI. High-sensitivity cardiac troponin (hs-cTn) assays may allow rapid rule-out of AMI and avoidance of unnecessary hospital admissions and anxiety.
OBJECTIVE: To assess the clinical effectiveness and cost-effectiveness of hs-cTn assays for the early (within 4 hours of presentation) rule-out of AMI in adults with acute chest pain.
METHODS: Sixteen databases, including MEDLINE and EMBASE, research registers and conference proceedings, were searched to October 2013. Study quality was assessed using QUADAS-2. The bivariate model was used to estimate summary sensitivity and specificity for meta-analyses involving four or more studies, otherwise random-effects logistic regression was used. The health-economic analysis considered the long-term costs and quality-adjusted life-years (QALYs) associated with different troponin (Tn) testing methods. The de novo model consisted of a decision tree and Markov model. A lifetime time horizon (60 years) was used.
RESULTS: Eighteen studies were included in the clinical effectiveness review. The optimum strategy, based on the Roche assay, used a limit of blank (LoB) threshold in a presentation sample to rule out AMI [negative likelihood ratio (LR-) 0.10, 95% confidence interval (CI) 0.05 to 0.18]. Patients testing positive could then have a further test at 2 hours; a result above the 99th centile on either sample and a delta (Î) of â„â20% has some potential for ruling in an AMI [positive likelihood ratio (LR+) 8.42, 95% CI 6.11 to 11.60], whereas a result below the 99th centile on both samples and a Î of <â20% can be used to rule out an AMI (LR- 0.04, 95% CI 0.02 to 0.10). The optimum strategy, based on the Abbott assay, used a limit of detection (LoD) threshold in a presentation sample to rule out AMI (LR- 0.01, 95% CI 0.00 to 0.08). Patients testing positive could then have a further test at 3 hours; a result above the 99th centile on this sample has some potential for ruling in an AMI (LR+ 10.16, 95% CI 8.38 to 12.31), whereas a result below the 99th centile can be used to rule out an AMI (LR- 0.02, 95% CI 0.01 to 0.05). In the base-case analysis, standard Tn testing was both most effective and most costly. Strategies considered cost-effective depending upon incremental cost-effectiveness ratio thresholds were Abbott 99th centile (thresholds of <âÂŁ6597), Beckman 99th centile (thresholds between ÂŁ6597 and ÂŁ30,042), Abbott optimal strategy (LoD threshold at presentation, followed by 99th centile threshold at 3 hours) (thresholds between ÂŁ30,042 and ÂŁ103,194) and the standard Tn test (thresholds over ÂŁ103,194). The Roche 99th centile and the Roche optimal strategy [LoB threshold at presentation followed by 99th centile threshold and/or Î20% (compared with presentation test) at 1-3 hours] were extendedly dominated in this analysis.
CONCLUSIONS: There is some evidence to suggest that hs-CTn testing may provide an effective and cost-effective approach to early rule-out of AMI. Further research is needed to clarify optimal diagnostic thresholds and testing strategies.
STUDY REGISTRATION: This study is registered as PROSPERO CRD42013005939. FUNDING: The National Institute for Health Research Health Technology Assessment programme
Am I overweight? A longitudinal study on parental and peers weight-related perceptions on dietary behaviors and weight status among adolescents
Objective: An investigation of the interplay between various types of adolescentsâ perceptions of weight status in predicting adolescentsâ nutrition behavior and their body mass was conducted. In particular, it was hypothesized that the relationship between parental and peersâ perceptions of their own weight status (reported by adolescents) and objectively measured weight status of adolescents would be mediated by three types of adolescentsâ weight status perceptions (adolescentsâ own weight perceptions, parental perceptions of adolescentsâ weight status perceived by participants, and peersâ perceptions of adolescentsâ weight status perceived by participants) and by adolescentsâ nutrition behaviors. Design: Data were collected twice, with a 13-month follow-up. Participants (N = 1096) were aged 14â20, with BMI ranging from 16.20 to 41.21. Multiple mediation analysis with two sequential mediators was applied. Main outcome measures: At the baseline adolescents completed the questionnaire assessing their nutrition behaviors and weight status perceptions. Weight and height were measured objectively at baseline and follow-up. Results: Two types of weight perceptions (adolescentsâ own weight status perceptions, peersâ perceptions of adolescentsâ weight status reported by participants), and adolescentsâ nutrition behaviors mediated the relationship between the othersâ own weight perceptions and adolescentsâ weight status. No indirect effects of othersâ own weight perceptions on adolescentsâ weight status through parental perceptions were found. Conclusion: Adolescentsâ nutrition behaviors and body weight status depend on what they think about their own weight status and what they think of their peersâ perceptions, but do not depend on what adolescents think of their parentsâ perceptions
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