How the Internet, the Sharing Economy, and Reputational Feedback Mechanisms Solve the “Lemons Problem”

This paper argues that the sharing economy—through the use of the Internet and real time reputational feedback mechanisms—is providing a solution to the lemons problem that many regulators have spent decades attempting to overcome. Section I provides an overview of the sharing economy and traces its rapid growth. Section II revisits the lemons theory as well as the various regulatory solutions proposed to deal with the problem of asymmetric information. Section III discusses the relationship between reputation and trust and analyzes how reputational incentives affect commercial interactions. Section IV discusses how information asymmetries were addressed in the pre-Internet era. It also discusses how the evolution of both the Internet and information systems (especially the reputational feedback mechanisms of the sharing economy) addresses the lemons problem. Section V explains how these new realities affect public policy and concludes that asymmetric information is not a legitimate rationale for policy intervention in light of technological changes. We also argue that continued use of this rationale to regulate in the name of consumer protection might, in fact, make consumers worse off. This has ramifications for the current debate over regulation of the sharing economy

An Investigation into Nanowire Formation via AFM, Neutron Scattering and various other methods

The formation of nanowire structures from poly(3-hexylthiophene) (P3HT) in solution is of great interest in fields such as vapour sensing and organic solar cells. Being able to control formation, deposition and characterise these nanowires is therefore of great interest to maximise the potential of these devices. To this end this research investigates the growth of these nanowires in solution via small angle neutron scattering, and ultra-violet visible spectroscopy. The ability to align these nanowires on a solid substrate is also of interest, as well as obtaining large quantities of aligned and densely packed nanowires. Therefore this thesis has investigated optimal processing conditions, deposition methods and post processing methods to get the optimal P3HT nanowires and nanowire alignment. Various methods of characterising the nanowires, such as ultra-violet visible spectroscopy, small angle neutron scattering, atomic force microscopy etc. have been used to characterise the nanowires that were created. These nanowires were also tested for use in applications such as vapour sensing, by use in water-gated transistors and the effects of using nanowires, rather than a thin film of P3HT was also investigated. In summary, various techniques for the production and optimisation of P3HT nanowire thin films were investigated, the growth of which was also carefully studied. Finally the nanowire films were characterised using various methods and applications tested to determine how to use nanowires to optimise these applications, namely for the purpose of vapour sensing

A flexible, open, and interactive digital platform to support online and blended experiential learning environments: Thinglink and thin sections

Abstract. This study investigates the potential value of, and provides a method for, the creation of flexible, digital, and asynchronous platforms to create student-centred materials for use in an online and/or blended learning environment. We made use of Thinglink to create a “virtual microscope” resource for geology and associated courses in higher education. This is achieved through the dissemination of a simple learning resource comprising interactive imagery and audio. The visual analysis of rocks under the microscope, termed thin-section petrography, is a fundamental component in geology programmes in higher education, with key skills which are transferable with other fields such as material science, biology, and forensic science. However, learning environments and activities in this field are often dictated by the requirement for access to microscope facilities and supplementary resources which are highly variable in their academic level, availability, design, and scale, ranging from traditional textbooks to online resources. A resource was created which allows individuals to experience some of the aspects of petrographic microscopy in a digital manner. In particular, specific features of the materials observed and how microscopes work were included. The resource was disseminated to a population of learners and educators, who provided responses to a questionnaire. Responses were overwhelmingly positive and indicate considerable interest from learner and teacher alike. Critical areas for improvement include the need for clarity in the user interface and the inclusion of a recorded human voice rather than automated text narration. This study highlights the need for, and benefits of, interactive online learning resources in petrology and associated fields. This type of resource has positive implications for the flexibility, inclusivity, and accessibility of teaching materials. Such resources may prove particularly valuable when distance learning is unavoidable (e.g. the COVID-19 crisis) and/or hybrid, blended learning environments are being deployed. The method and platform used in this study are highly transferable to other subject areas (or other areas of the geosciences)

Delivery of Antibody Mimics into Mammalian Cells via Anthrax Toxin Protective Antigen

Antibody mimics have significant scientific and therapeutic utility for the disruption of protein–protein interactions inside cells; however, their delivery to the cell cytosol remains a major challenge. Here we show that protective antigen (PA), a component of anthrax toxin, efficiently transports commonly used antibody mimics to the cytosol of mammalian cells when conjugated to the N-terminal domain of LF (LFN). In contrast, a cell-penetrating peptide (CPP) was not able to deliver any of these antibody mimics into the cell cytosol. The refolding and binding of a transported tandem monobody to Bcr-Abl (its protein target) in chronic myeloid leukemia cells were confirmed by co-immunoprecipitation. We also observed inhibition of Bcr-Abl kinase activity and induction of apoptosis caused by the monobody. In a separate case, we show disruption of key interactions in the MAPK signaling pathway after PA-mediated delivery of an affibody binder that targets hRaf-1. We show for the first time that PA can deliver bioactive antibody mimics to disrupt intracellular protein–protein interactions. This technology adds a useful tool to expand the applications of these modern agents to the intracellular milieu.Massachusetts Institute of Technology (Startup funds)Massachusetts Institute of Technology (MIT Reed Fund)National Science Foundation (U.S.) (NSF CAREER Award (CHE-1351807))Damon Runyon Cancer Research Foundation (award)National Science Foundation (U.S.) (Graduate Research Fellowship

Top ten accelerating cosmological models

Recent astronomical observations indicate that the Universe is presently almost flat and undergoing a period of accelerated expansion. Basing on Einstein's general relativity all these observations can be explained by the hypothesis of a dark energy component in addition to cold dark matter (CDM). Because the nature of this dark energy is unknown, it was proposed some alternative scenario to explain the current accelerating Universe. The key point of this scenario is to modify the standard FRW equation instead of mysterious dark energy component. The standard approach to constrain model parameters, based on the likelihood method, gives a best-fit model and confidence ranges for those parameters. We always arbitrary choose the set of parameters which define a model which we compare with observational data. Because in the generic case, the introducing of new parameters improves a fit to the data set, there appears the problem of elimination of model parameters which can play an insufficient role. The Bayesian information criteria of model selection (the AIC and BIC) are dedicated to promotion a set of parameters which should be incorporated to the model. We divide class of all accelerating cosmological models into two groups according to the two types of explanation acceleration of the Universe. Then the Bayesian framework of model selection is used to determine the set of parameters which gives preferred fit to the SNIa data. We find a few of flat cosmological models which can be recommend by both the Bayes factor and Akaike information criterion.Comment: RevTeX4, 11 pages, 7 figures; v2 some clarifications, bibliography additions, new figure (comparisons with respect to LambdaCDM

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

Aberrant Water Homeostasis Detected by Stable Isotope Analysis

While isotopes are frequently used as tracers in investigations of disease physiology (i.e., 14C labeled glucose), few studies have examined the impact that disease, and disease-related alterations in metabolism, may have on stable isotope ratios at natural abundance levels. The isotopic composition of body water is heavily influenced by water metabolism and dietary patterns and may provide a platform for disease detection. By utilizing a model of streptozotocin (STZ)-induced diabetes as an index case of aberrant water homeostasis, we demonstrate that untreated diabetes mellitus results in distinct combinations, or signatures, of the hydrogen (δ2H) and oxygen (δ18O) isotope ratios in body water. Additionally, we show that the δ2H and δ18O values of body water are correlated with increased water flux, suggesting altered blood osmolality, due to hyperglycemia, as the mechanism behind this correlation. Further, we present a mathematical model describing the impact of water flux on the isotopic composition of body water and compare model predicted values with actual values. These data highlight the importance of factors such as water flux and energy expenditure on predictive models of body water and additionally provide a framework for using naturally occurring stable isotope ratios to monitor diseases that impact water homeostasis

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO