Arbitrage, market definition and monitoring a time series approach

This article considers the application to regional price data of time series methods to test stationarity, multivariate cointegration and exogeneity. The discovery of stationary price differentials in a bivariate setting implies that the series are rendered stationary by capturing a common trend and we observe through this mechanism long-run arbitrage. This is indicative of a broader market definition and efficiency. The problem is considered in relation to more than 700 weekly data points on gasoline prices for three regions of the US and similarly calibrated simulated series. The discovery of a single common trend is consistent with competitive pricing and a broad market definition, but the finding of a single weakly exogenous variable affects this conclusion

Examination of the impact and effectiveness of herd health and welfare assessment in im-proving animal welfare on organic dairy farms, using qualitative interviews.

During winter 2002-03, 15 organic dairy farms in SW England participated in a herd health and welfare assessment and benchmarking study. A second assessment was carried out on 14 of the original 15 farms and on 14 new farms during winter 2003-04. The effectiveness of the herd health and welfare as-sessments and benchmarking in delivering animal health and welfare improvements was investigated by means of qualitative research interviews. The inter-views were conducted between August and November 2004. The average length of interview was one hour and fifteen minutes. Five common themes were iden-tified and headed ‘Sensitivities and misgivings’; ‘Ac-ceptability of scoring methodology and indicators assessed’; ‘Raised awareness and motivation to im-prove’; ‘Veterinary support and herd health planning’ and ‘Value of assessment and benchmarking’. It was apparent that farmers, who took part voluntarily in the study, took the results of the herd health and welfare assessments very seriously and were clearly motivated by the process. The main focus for change was related to housing issues. The main constraints to welfare improvement were a shortage of finance to affect change beyond relatively simple alterations and a lack of information on the identification of changes likely to improve animal welfare in given situations

A combined R-matrix eigenstate basis set and finite-differences propagation method for the time-dependent Schr\"{od}dinger equation: the one-electron case

In this work we present the theoretical framework for the solution of the time-dependent Schr\"{o}dinger equation (TDSE) of atomic and molecular systems under strong electromagnetic fields with the configuration space of the electron's coordinates separated over two regions, that is regions $I$ and $II$. In region $I$ the solution of the TDSE is obtained by an R-matrix basis set representation of the time-dependent wavefunction. In region $II$ a grid representation of the wavefunction is considered and propagation in space and time is obtained through the finite-differences method. It appears this is the first time a combination of basis set and grid methods has been put forward for tackling multi-region time-dependent problems. In both regions, a high-order explicit scheme is employed for the time propagation. While, in a purely hydrogenic system no approximation is involved due to this separation, in multi-electron systems the validity and the usefulness of the present method relies on the basic assumption of R-matrix theory, namely that beyond a certain distance (encompassing region $I$) a single ejected electron is distinguishable from the other electrons of the multi-electron system and evolves there (region II) effectively as a one-electron system. The method is developed in detail for single active electron systems and applied to the exemplar case of the hydrogen atom in an intense laser field.Comment: 13 pages, 6 figures, submitte

Ionization of hydrogen atoms by electron impact at 1eV, 0.5eV and 0.3eV above threshold

We present here triple differential cross sections for ionization of hydrogen atoms by electron impact at 1eV, 0.5eV and 0.3eV energy above threshold, calculated in the hyperspherical partial wave theory. The results are in very good agreement with the available semiclassical results of Deb and Crothers \cite{DC02} for these energies. With this, we are able to demonstrate that the hyperspherical partial wave theory yields good cross sections from 30 eV \cite{DPC03} down to near threshold for equal energy sharing kinematics.Comment: 6 pages, 9 figure

Ultra-high speed electro-optical systems employing fiber optics final report

Ultrahigh speed electro-optical systems employing fiber optic

Half-Life of 14^{14}O

We have measured the half-life of $^{14}$O, a superallowed $(0^{+} \to 0^{+})$ $\beta$ decay isotope. The $^{14}$O was produced by the $^{12}$C($^{3}$He,n)$^{14}$O reaction using a carbon aerogel target. A low-energy ion beam of $^{14}$O was mass separated and implanted in a thin beryllium foil. The beta particles were counted with plastic scintillator detectors. We find $t_{1/2} = 70.696\pm 0.052$ s. This result is $1.5\sigma$ higher than an average value from six earlier experiments, but agrees more closely with the most recent previous measurement.Comment: 10 pages, 5 figure

Confinement effects in a guided-wave interferometer with millimeter-scale arm separation

Guided-wave atom interferometers measure interference effects using atoms held in a confining potential. In one common implementation, the confinement is primarily two-dimensional, and the atoms move along the nearly free dimension under the influence of an off-resonant standing wave laser beam. In this configuration, residual confinement along the nominally free axis can introduce a phase gradient to the atoms that limits the arm separation of the interferometer. We experimentally investigate this effect in detail, and show that it can be alleviated by having the atoms undergo a more symmetric motion in the guide. This can be achieved by either using additional laser pulses or by allowing the atoms to freely oscillate in the potential. Using these techniques, we demonstrate interferometer measurement times up to 72 ms and arm separations up to 0.42 mm with a well controlled phase, or times of 0.91 s and separations of 1.7 mm with an uncontrolled phase.Comment: 14 pages, 6 figure

Average and worst-case specifications of precipitating auroral electron environment

The precipitation electrons in the auroral environment are highly variable in their energy and intensity in both space and time. As such they are a source of potential hazard to the operation of the Space Shuttle and other large spacecraft operating in polar orbit. In order to assess these hazards both the average and extreme states of the precipitating electrons must be determined. Work aimed at such a specification is presented. First results of a global study of the average characteristics are presented. In this study the high latitude region was divided into spatial elements in magnetic local time and corrected geomagnetic latitude. The average electron spectrum was then determined in each spatial element for seven different levels of activity as measured by K sub p using an extremely large data set of auroral observations. Second a case study of an extreme auroral electron environment is presented, in which the electrons are accelerated through field aligned potential as high as 30,000 volts and in which the spacecraft is seen to charge negatively to a potential approaching .5 kilovolts

Adaptability

Adaptability is usually conceived as a psychological capacity that sustains adaptive behaviors, allowing one to face and manage stressors. It promotes adjustment between a person and its environment through a constant, dynamic, and dialectic interaction between them. Adaptability is conceptually and empirically distinct from dispositions such as personality or intelligence, but can be considered as a self-regulation process promoting an adequate person-environment fit (P-E fit), psychological health, and positive career-related outcomes, such as employability, employment, or work engagement. Adaptability evolves according to the circumstances and people can activate their adaptive abilities in adverse situations. Brief psychological interventions increase adaptability, which in turn improves employability and career success