INFORMATION IMPACTS AND DETERMINANTS OF INFORMATION SELECTION: AN EXPERIMENTAL APPROACH

Laboratory experimentation was used to assess the impacts of information disclosure in imperfect markets. A dual oligopoly market structure was designed with contract information disclosed to subjects under three treatments: no, partial, and full disclosure. Regression analysis revealed some increase in selling price with full information disclosure, but no discernable effects on negotiated prices with partial disclosure. Alternative specifications showed large traders earning significantly lower profits, and information on large traders significantly beneficial to both buyers and sellers. Probit analysis of information selection determinants revealed no significant economic content in trader requests for information under partial disclosure.Marketing,

Understanding how kurtosis is transferred from input acceleration to stress response and it's influence on fatigue life

High cycle fatigue of metals typically occurs through long term exposure to time varying loads which, although modest in amplitude, give rise to microscopic cracks that can ultimately propagate to failure. The fatigue life of a component is primarily dependent on the stress amplitude response at critical failure locations. For most vibration tests, it is common to assume a Gaussian distribution of both the input acceleration and stress response. In real life, however, it is common to experience non-Gaussian acceleration input, and this can cause the response to be non-Gaussian. Examples of non-Gaussian loads include road irregularities such as potholes in the automotive world or turbulent boundary layer pressure fluctuations for the aerospace sector or more generally wind, wave or high amplitude acoustic loads. The paper first reviews some of the methods used to generate non-Gaussian excitation signals with a given power spectral density and kurtosis. The kurtosis of the response is examined once the signal is passed through a linear time invariant system. Finally an algorithm is presented that determines the output kurtosis based upon the input kurtosis, the input power spectral density and the frequency response function of the system. The algorithm is validated using numerical simulations. Direct applications of these results include improved fatigue life estimations and a method to accelerate shaker tests by generating high kurtosis, non-Gaussian drive signals

Can retinal ganglion cell dipoles seed iso-orientation domains in the visual cortex?

It has been argued that the emergence of roughly periodic orientation preference maps (OPMs) in the primary visual cortex (V1) of carnivores and primates can be explained by a so-called statistical connectivity model. This model assumes that input to V1 neurons is dominated by feed-forward projections originating from a small set of retinal ganglion cells (RGCs). The typical spacing between adjacent cortical orientation columns preferring the same orientation then arises via Moir\'{e}-Interference between hexagonal ON/OFF RGC mosaics. While this Moir\'{e}-Interference critically depends on long-range hexagonal order within the RGC mosaics, a recent statistical analysis of RGC receptive field positions found no evidence for such long-range positional order. Hexagonal order may be only one of several ways to obtain spatially repetitive OPMs in the statistical connectivity model. Here, we investigate a more general requirement on the spatial structure of RGC mosaics that can seed the emergence of spatially repetitive cortical OPMs, namely that angular correlations between so-called RGC dipoles exhibit a spatial structure similar to that of OPM autocorrelation functions. Both in cat beta cell mosaics as well as primate parasol receptive field mosaics we find that RGC dipole angles are spatially uncorrelated. To help assess the level of these correlations, we introduce a novel point process that generates mosaics with realistic nearest neighbor statistics and a tunable degree of spatial correlations of dipole angles. Using this process, we show that given the size of available data sets, the presence of even weak angular correlations in the data is very unlikely. We conclude that the layout of ON/OFF ganglion cell mosaics lacks the spatial structure necessary to seed iso-orientation domains in the primary visual cortex.Comment: 9 figures + 1 Supplementary figure and 1 Supplementary tabl

The long-term effectiveness of efavirenz-based combination antiretroviral therapy, the impact of pharmacogenomics and pharmacokinetic interaction of artemisinin-based antimalarial therapy on efavirenz exposure among Ghanaian HIV-infected patients

Dr. Fred Stephen Sarfo, The long-term effectiveness of efavirenz-based combination antiretroviral therapy, the impact of pharmacogenomics and pharmacokinetic interaction of artemisinin-based antimalarial therapy on efavirenz exposure among Ghanaian HIV-infected patients. PhD dissertation, Durham University, January 2013. Introduction: In sub-Saharan Africa, HIV treatment is initiated with combination of antiretroviral medications comprising of a backbone of either stavudine or zidovudine plus lamivudine with a non-nucleoside reverse transcriptase inhibitor of either efavirenz or nevirapine. Efavirenz is highly efficacious, durable and well tolerated. The risk for toxicity of efavirenz is determined by several factors including single nucleotide polymorphisms in the hepatic enzymes responsible for its metabolism and concurrently administered medications such as antimalarials, which share common metabolic pathways. The aims of this dissertation are to assess the long-term effectiveness of efavirenz-based antiretroviral therapy and the impact of pharmogenomics and pharmacokinetic interactions of artemisinin-based antimalarial therapy on efavirenz exposure among Ghanaian HIV-infected patients. Methods: The effectiveness of efavirenz- compared with nevirapine-based antiretroviral therapy was assessed retrospectively in nearly 4000 patients starting treatment between 2004 and 2010. The main outcome measure was a composite of toxicity, disease progression and attrition, and CD4 count changes. A prospective pharmacokinetic study of artesunate and efavirenz was conducted among 22 HIV-infected and 21 controls. Plasma efavirenz and artesunate/ dihydroartemisinin concentrations were measured using validated and standardised methods. Genotyping for single nucleotide polymorphisms in CYP2B6 G516T, T983C; CYP2A6*9B, UGT2B7*735 and *802 as well as CAR rs2307424 were performed for 800 patients with real-time polymerase chain reaction with allelic discrimination. Results: Antiretroviral therapy was associated with robust CD4 increases. Efavirenz was comparable with nevirapine in composite outcomes but better tolerated. Artesunate was well tolerated when administered to HIV-infected patients on efavirenz. Single nucleotide polymorphisms in the CYP2B6 G516T and T983C were associated with increased plasma efavirenz concentrations. Conclusions/Recommendation: Among this Ghanaian cohort, both efavirenz and nevirapine-based antiretroviral therapy were effective. The better tolerability of efavirenz compared with nevirapine means it can be safely used as the preferred first line non-nucleoside reverse transcriptase inhibitor in sub-Saharan Africa

EFFECT OF CONTRACT DISCLOSURE ON PRICE: RAILROAD GRAIN CONTRACTING IN THE PLAINS

The Staggers Rail Act of 1980 granted railroads freedom to establish rates and enter into confidential contracts with grain shippers. Recent legislation (1986) required that certain contract terms be disclosed. This study shows rail rates in the Plains region commenced an upward trend after implementation of the disclosure policy. Results suggest contract disclosure and increased reliance on posted tariffs facilitated rate coordination within the oligopolistic railroad industry.Public Economics,

Bounds on higher-order Lorentz-violating photon sector coefficients from an asymmetric optical ring resonator experiment

Optical resonators provide a powerful tool for testing aspects of Lorentz invariance. Here, we present a reanalysis of an experiment where a path asymmetry was created in an optical ring resonator by introducing a dielectric prism in one arm. The frequency difference of the two fundamental counter-propagating modes was then recorded as the apparatus was orientation-modulated in the laboratory. By assuming that the minimal Standard-Model Extension coefficients vanish we are able to place bounds on higher-order parity-odd Lorentz-violating coefficients of the Standard-Model Extension. The results presented in this work set the first constraints on two previously unbounded linear combinations of d=8 parity-odd nonbirefringent nondispersive coefficients of the photon sector.Comment: 6 pages, 4 figures, 3 tables, accepted for publication in Physics Letters

Home Occupancy Agent: Occupancy and Sleep Detection

Smart homes of the future will have a numberof different types of sensors. What types of sensors and howthey will be used depends on the behaviour needed from thesmart home. Using the sensors to automatically determine ifa home is occupied can lead to a wide range of benefits. Forexample, it could trigger a change in the thermostat setting tosave money, or even a change in security monitoring systems.Our prototype Home Occupancy Agent (HOA), which we presentin this paper, uses a rule based system that monitors powerconsumption from meters and ambient light sensor readings inorder to determine occupancy. The agent is also able to determinewhen the occupants are asleep, and thus provide the potentialfor further energy saving opportunities

Akyem, c. 1700-1874: A Study in Inter-State Relations in Pre-Colonial Gold Coast.

During the first quarter of the eighteenth century and long after, Bosome led a politically unexciting life. In contrast, the other two Akyem states, Abuakwa and Kotoku, pursued an aggressive foreign policy and tightly guarded their independence against hostile neighbours. Between 1730 and 1742 they acquired imperial domination over the eastern half of the Gold Coast west of the Volta. In 1744, however, Kotoku succumbed to Asante authority. Abuakwa resisted Asante but yielded to that power in 1783. The fall of the Akyem empire increased the area of Asante domination. The Asante yoke proved unbearable; consequently between 1810 and 1831 the Akyem states, as members of an Afro-European alliance, fought a successful war of independence against that power. The European co-operation, however, led to an Anglo-Danish rivalry for Akyem, Akuapem, and Krobo as spheres of influence: the rivalry ended in 185O. Continued threat from Asante and bitter intra-Akyem relations compelled the Akyem states to tolerate British protection. The invasion of Kotoku-Bosome territory by Asante in 1863 underlined the wisdom in remaining under the British canopy. In late l860s the Kotoku, for example, affirmed their loyalty to the British by helping to re-establish British authority in the Lower Volta District from which it had been withdrawn in 1860. The Kotoku involvement in the Volta conflicts, traditional animosity, and Anglo-Dutch deal over Elmina inspired Asante invasion of Akyem and other parts of the Protectorate in late 1872 and 1873. Close Akyem co-operation enabled the British to counterattack Asante successfully in 1874. The Akyem also incited Juaben secession from Asante and promoted the founding of the New Juaben State in Akyem. But the price for all this was the subjection of the Akyem and almost every other Gold Coast people to British colonial rule as from mid-1874

Provincetown--auditorium for music and experimental drama

Thesis (M. Arch.)--Massachusetts Institute of Technology, Dept. of Architecture, 1955.Accompanying drawings held by MIT Museum.Includes bibliographical references (leaf 38 ).by Stephen Shiowitz and Fred M. Taylor.M.Arch

Thora

[Verse 1] I stand in a land of roses, But I dream of a land of snow, Where you and I were happy In the years of long ago. Nightingales in the branches, Stars in the magic skies, But I only hear you singing, I only see your eyes. Come! Come! Come to me, Thora, Come once again and be Child of my dream, light of my life, Angel of love to me! [Verse 2]I stand again in the North land, But in silence and in shame; Your grave is my only landmark, And men have forgotten my name. ‘Tis a take that is truer and older Than any the sagas tell, I loved you in life too little, I love you in death too well! Speak! Speak! Speak to me, Thora Speak from your Heaven to me; Child of my dream, love of my life, Hope of my world to be