Market Performance of Potato Auctions in Bhutan

Market performance with respect to a main horticultural export commodity in Bhutan is the subject of this paper. Imperfections in (market) infrastructure and market structure and conduct may prevent an optimal price for farmers. Market performance is assessed by testing the law of one price for this commodity. This is done by testing three series of auction price data on both long-run and short-run price integration. It is concluded that auction prices were interrelated both in the long and short run with one of the three auctions as the price-leading market. Policy implications are suggested.Auctions, Bhutan, Law of one price, Market performance, Potato marketing, Marketing, C22, L1, M31, O1, Q13,

Vertical Price Leadership on Local Maize Markets in Benin

This paper considers vertical price relationships between wholesalers and retailers on five local maize markets in Benin. We show that if the common factor and the long-run disequilibrium error are not explicitly taken into account in testing the channel model, one can easily be wrong about how restrictions on the error-correction structure must be interpreted in terms of economic power in the channel. The empirical results show interesting differences between markets and reveal that retailers play a more prominent role in the price formation process than generally assumed in the literature. Retailers in the two major towns do not allow wholesalers to behave as vertical price leaders, but in the two larger rural centers, wholesalers involved in arbitrage among urban markets are able to influence price formation.Vertical price leadership, Marketing channels, Cointegration, Common Factor, Benin, Demand and Price Analysis, C32, D40, L10, O18, Q13,

Simulation Application for the LHCb Experiment

We describe the LHCb detector simulation application (Gauss) based on the Geant4 toolkit. The application is built using the Gaudi software framework, which is used for all event-processing applications in the LHCb experiment. The existence of an underlying framework allows several common basic services such as persistency, interactivity, as well as detector geometry description or particle data to be shared between simulation, reconstruction and analysis applications. The main benefits of such common services are coherence between different event-processing stages as well as reduced development effort. The interfacing to Geant4 toolkit is realized through a facade (GiGa) which minimizes the coupling to the simulation engine and provides a set of abstract interfaces for configuration and event-by-event communication. The Gauss application is composed of three main blocks, i.e. event generation, detector response simulation and digitization which reflect the different stages performed during the simulation job. We describe the overall design as well as the details of Gauss application with a special emphasis on the configuration and control of the underlying simulation engine. We also briefly mention the validation strategy and the planing for the LHCb experiment simulation.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 6 pages, LaTeX, 9 eps figures. PSN TUMT00

Suppression of Zeeman gradients by nuclear polarization in double quantum dots

We use electric dipole spin resonance to measure dynamic nuclear polarization in InAs nanowire quantum dots. The resonance shifts in frequency when the system transitions between metastable high and low current states, indicating the presence of nuclear polarization. We propose that the low and the high current states correspond to different total Zeeman energy gradients between the two quantum dots. In the low current state, dynamic nuclear polarization efficiently compensates the Zeeman gradient due to the $g$-factor mismatch, resulting in a suppressed total Zeeman gradient. We present a theoretical model of electron-nuclear feedback that demonstrates a fixed point in nuclear polarization for nearly equal Zeeman splittings in the two dots and predicts a narrowed hyperfine gradient distribution

Physical health and the onset and persistence of depression in older adults: an eight-wave prospective community based study.

Background. Poor physical health has long been recognized to be one of the most important risk factors for depression in older adults. Since many aspects of physical health can be targeted for improvement in primary care, it is important to know whether physical health problems predict the onset and/or the persistence of depression. Methods. The study is based on a sample which at the outset consisted of 327 depressed and 325 non-depressed older adults (55-85) drawn from a larger random community-based sample in the Netherlands. Depression was measured using the Center for Epidemiologic Studies Depression scale (CES-D) at eight successive waves. Results. From all incident episodes, the majority (57%) was short-lived. These short episodes could generally not be predicted by physical health problems. The remaining incident episodes (43%) were not short-lived and could be predicted by poor physical health. Chronicity (34%) was also predicted by physical health problems. Conclusions. The study design with its frequent measurements recognized more incident cases than previous studies; these cases however did have a better prognosis than is often assumed. The prognosis of prevalent cases was rather poor. Physical health problems were demonstrated to be a predictor of both the onset and the persistence of depression. This may well have implications for prevention and intervention