Astrometry with the Hubble Space Telescope: Trigonometric Parallaxes of Selected Hyads

We present absolute parallaxes and proper motions for seven members of the Hyades open cluster, pre-selected to lie in the core of the cluster. Our data come from archival astrometric data from FGS 3, and newer data for 3 Hyads from FGS 1R, both white-light interferometers on the Hubble Space Telescope (HST). We obtain member parallaxes from six individual Fine Guidance Sensor (FGS) fields and use the field containing van Altena 622 and van Altena 627 (= HIP 21138) as an example. Proper motions, spectral classifications and VJHK photometry of the stars comprising the astrometric refer- ence frames provide spectrophotometric estimates of reference star absolute parallaxes. Introducing these into our model as observations with error, we determine absolute parallaxes for each Hyad. The parallax of vA 627 is significantly improved by including a perturbation orbit for this previously known spectroscopic binary, now an astrometric binary. Compared to our original (1997) determina- tions, a combination of new data, updated calibration, and improved analysis lowered the individual parallax errors by an average factor of 4.5. Comparing parallaxes of the four stars contained in the Hipparcos catalog, we obtain an average factor of 11 times improvement with the HST . With these new results, we also have better agreement with Hipparcos for the four stars in common. These new parallaxes provide an average distance for these seven members, = 47.5 pc, for the core a \pm 1 - {\sigma} dispersion depth of 3.6 pc, and a minimum depth from individual components of 16.0 \pm 0.9 pc. Absolute magnitudes for each member are compared to established main sequences, with excellent agreement. We obtain a weighted average distance modulus for the core of the Hyades of m-M=3.376 \pm 0.01, a value close to the previous Hipparcos values, m-M=3.33\pm 0.02.Comment: 21 pages, 7 figures, Astronomical Journal, accepted 2011-3-

NF96-290 Irrigation Management Practices in Nebraska

This NebFact has information on a variety of new irrigation practices

THE CONTRIBUTION OF ENVIRONMENTAL AMENITIES TO AGRICULTURAL LAND VALUES: HEDONIC MODELLING USING GEOGRAPHIC INFORMATION SYSTEMS DATA

Geographic Information Systems (GIS) data are used in a hedonic model to measure the impact of recreational and scenic amenities on agricultural land values. Results indicate agricultural land values are determined by environmental amenities as well as production attributes. Significant amenity variables included scenic view, elk habitat and fishery productivity.Environmental Economics and Policy, Land Economics/Use,

Transcutaneous Electrical Nerve Stimulation (TENS) for neuropathic pain in adults (Protocol)

This is the protocol for a review and there is no abstract. The objectives are as follows: To determine the analgesic effectiveness of TENS versus placebo (sham) TENS, TENS versus usual care, TENS versus no treatment and TENS in addition to usual care versus usual care alone in the management of neuropathic pain in adults

Recent Decisions

Comments on recent decisions by William J. Daner, William T. Huston, James D. Matthews, Benedict R. Danko, John E. Lindberg, Maynard R. Bissonnette, Joseph H. Harrison, Peter J. Donahue, Louis J. Mustico, Donald John Tufts, Henry M. Shine, Jr., Arthur L. Beaudette, Luke R. Morin, John F. Mendoza, and Thomas A. Muscatello

Pot roasting of lead ores

In this thesis for a starting point, we attempted a roast of straight galena with no diluent. As anticipated the results were nil. We next attempted the roast with a mixture of galena and silica, and obtained fair results. Our next experiment was to use limestone with the galena. Because of the large percentage of limestone present the results were not satisfactory. Next pyrites and limestone were used with the galena, and excellent results were obtained. We made another run, using pyrites and limestone, but increasing the per-centage of galena by 25%. This run was also very successful. From these few runs, the data we are able to glean from periodicals, and the rational chemical analysis that we made on the roasted product, we base our thesis --Introduction, pages 1 -2

Decompositions of Free Energies in Molecular Simulation

This thesis describes advances in methods to measure free energy changes in simulations of molecular systems. In each case the free energy is decomposed into local environments which reveal insights about the complex systems being studied. Free energy is a fundamental quantity that can be used to predict whether changes in state are physically favourable. This can be used to predict the solubility of molecules and whether molecules are likely to bind to proteins. There are a handful of methods which measure free energy from molecular simulations. In chapter 3 we show results for an improved endpoint free energy method using inhomogeneous fluid solvation theory (IFST) which takes second order fluid-fluid entropy corrections into account. This is applied to a system of Lennard-Jones particles which show no measurable second order entropy contribution which fits with theoretical predictions. In chapter 4 an adaptation to the Zwanzig equation for path based exponential averaging methods is made. The equation is expanded to give contributions associated with every atom in the system. This method is called atomwise free energy perturbation and is applied to small molecules and ligand-protein binding. In chapter 5, IFST is applied to decompose hydration free energy at the surface of a protein into hydration sites. From these sites, information is inferred about the binding conformation of two proteins GABARAP and the GABA-A receptor. In chapter 6 statistics from hydration sites around hundreds of proteins are analysed. The distributions of free energy are shown and discussed for hydration sites in a range of local chemical environments. Also in chapter 6, the hydration sites decomposition method is augmented with local energy information associated with replacing a water molecule at a hydration site with a probe. The probe represents a ligand, and this is compared to the binding site prediction from the previous method. Further suggestions for improvements are made