Temperature control of a cryogenic bath

Foreign gas introduced into vapor phase above liquid region cools cryogenic baths. Equipment consists of gas tank and cover of styrofoam. Helium is considered the best choice to produce cooling, though any gas with boiling point lower than that of bath liquid may be used

Water bathing alters the speed-accuracy trade-off of escape flights in European starlings

Birds of most species regularly bathe in water, but the function of this behaviour is unknown. We tested the hypothesis that water bathing is important in feather maintenance, and hence should enhance flight performance. We manipulated European starlings', Sturnus vulgaris, access to bathing water in a 2 × 2 design: birds were housed in aviaries either with or without water baths for a minimum of 3 days (long-term access) before being caught and placed in individual cages either with or without water baths for a further 24 h (short-term access). We subsequently assessed the speed and accuracy of escape flights through an obstacle course of vertical strings. Birds that had bathed in the short-term flew more slowly and hit fewer strings than birds that were deprived of bathing water in the short term, whereas long-term access to bathing water had no significant effect on flight performance. Thus recent access to bathing water alters flight performance by altering the trade-off between escape flight speed and accuracy. We hypothesize that lack of bathing water provision could increase anxiety in captive starlings because of an increase in their perceived vulnerability to predation. This study therefore potentially provides an important functional link between the expression of natural behaviours in captivity and welfare considerations. © 2009 The Association for the Study of Animal Behaviour

Quantification of abnormal repetitive behaviour in captive European starlings (Sturnus vulgaris).

Stereotypies are repetitive, unvarying and goalless behaviour patterns that are often considered indicative of poor welfare in captive animals. Quantifying stereotypies can be difficult, particularly during the early stages of their development when behaviour is still flexible. We compared two methods for objectively quantifying the development of route-tracing stereotypies in caged starlings. We used Markov chains and T-pattern analysis (implemented by the software package, Theme) to identify patterns in the sequence of locations a bird occupied within its cage. Pattern metrics produced by both methods correlated with the frequency of established measures of stereotypic behaviour and abnormal behaviour patterns counted from video recordings, suggesting that both methods could be useful for identifying stereotypic individuals and quantifying stereotypic behaviour. We discuss the relative benefits and disadvantages of the two approaches

Judicial Review of Agency Delays Caused by a Lack of Appropriations: The Yucca Two-Step

Article published in the Michigan State Law Review

Building Fully Adaptive Stochastic Models for Multiphase Blowdown Simulations.

A new method for uncertainty quantification (UQ) that combines adaptivity in the physical (deterministic) space and the stochastic space is presented. The sampling-based method adaptively refines the physical discretizations of the simulations, along with adaptively building a stochastic model and adding samples. By adaptively refining the physical and stochastic models, errors from both spaces are balanced. The UQ method takes advantage of an active linear subspace to reduce the dimensionality of the stochastic space while retaining relevant interaction terms and anisotropy. Driven by low-cost error estimates, a particle-swarm optimization method explores the stochastic space and drives adaptation that results in an efficient stochastic approximation. The UQ method is compared to to two modern methods for three test functions in a 100-dimensional space. The current method is shown to result in up to three orders of magnitude lower error and up to two orders of magnitude fewer samples. Next, a simulation is developed using the discontinuous Galerkin method which is well-suited to adaptivity. A transient multiphase flashing flow model is used to simulate the Edwards-O'Brien blowdown problem. The adjoint equations are successfully solved and used to drive a space-time anisotropic adaptation based on a complex output of interest. This results in an efficient phsyical discretization. Finally, the UQ method is used to assess modeling and discretization errors in a modified multiphase flow simulation. Based on an overall stochastic output of interest, the UQ method simultaneously drives adaptation of the stochastic and deterministic discretizations in order to balance the two sources of error. That is, terms are added to the stochastic model, samples are added, and the physical grid of each individual simulation is refined simultaneously. Error estimates based on semi-refined discretizations retain anisotropic accuracy, and a common grid is used to compare solutions from samples. The method for combined adaptivity performs well on the test problem, reducing the stochastic dimensionality from 20 to two and reducing deterministic errors on select samples. For about the same computational time, the method results in an order of magnitude less error and an order of magnitude fewer degrees of freedom compared to three other methods.PhDAerospace EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/111612/1/isaaca_1.pd

Covariant quantum measurements may not be optimal

Quantum particles, such as spins, can be used for communicating spatial directions to observers who share no common coordinate frame. We show that if the emitter's signals are the orbit of a group, then the optimal detection method may not be a covariant measurement (contrary to widespread belief). It may be advantageous for the receiver to use a different group and an indirect estimation method: first, an ordinary measurement supplies redundant numerical parameters; the latter are then used for a nonlinear optimal identification of the signal.Comment: minor corrections, to appear in J. Mod. Opt. (proc. of Gdansk conf.

The Populations of Comet-Like Bodies in the Solar system

A new classification scheme is introduced for comet-like bodies in the Solar system. It covers the traditional comets as well as the Centaurs and Edgeworth-Kuiper belt objects. At low inclinations, close encounters with planets often result in near-constant perihelion or aphelion distances, or in perihelion-aphelion interchanges, so the minor bodies can be labelled according to the planets predominantly controlling them at perihelion and aphelion. For example, a JN object has a perihelion under the control of Jupiter and aphelion under the control of Neptune, and so on. This provides 20 dynamically distinct categories of outer Solar system objects in the Jovian and trans-Jovian regions. The Tisserand parameter with respect to the planet controlling perihelion is also often roughly constant under orbital evolution. So, each category can be further sub-divided according to the Tisserand parameter. The dynamical evolution of comets, however, is dominated not by the planets nearest at perihelion or aphelion, but by the more massive Jupiter. The comets are separated into four categories -- Encke-type, short-period, intermediate and long-period -- according to aphelion distance. The Tisserand parameter categories now roughly correspond to the well-known Jupiter-family comets, transition-types and Halley-types. In this way, the nomenclature for the Centaurs and Edgeworth-Kuiper belt objects is based on, and consistent with, that for comets.Comment: MNRAS, in press, 11 pages, 6 figures (1 available as postscript, 5 as gif). Higher resolution figures available at http://www-thphys.physics.ox.ac.uk/users/WynEvans/preprints.pd