Implications of Atmospheric Differential Refraction for Adaptive Optics Observations

Many adaptive optics systems operate by measuring the distortion of the wavefront in one wavelength range and performing the scientific observations in a second, different wavelength range. One common technique is to measure wavefront distortions at wavelengths <~1 micron while operating the science instrument at wavelengths >~1 micron. The index of refraction of air decreases sharply from shorter visible wavelengths to near-infrared wavelengths. Therefore, because the adaptive optics system is measuring the wavefront distortion in one wavelength range and the science observations are performed at a different wavelength range, residual image motion occurs and the maximum exposure time before smearing of the image can be significantly limited. We demonstrate the importance of atmospheric differential refraction, present calculations to predict the effect of atmospheric differential refraction, and finally discuss the implications of atmospheric differential refraction for several current and proposed observatories.Comment: PASP, accepted 15 January 200

Wind information display system user's manual

The Wind Information Display System (WINDS) provides flexible control through system-user interaction for collecting wind shear data, processing this data in real time, displaying the processed data, storing raw data on magnetic tapes, and post-processing raw data. The data are received from two asynchronous laser Doppler velocimeters (LDV's) and include position, velocity and intensity information. The raw data is written onto magnetic tape for permanent storage and is also processed in real time to depict wind velocities in a given spacial region

Fluidic hydrogen detector production prototype development

A hydrogen gas sensor that can replace catalytic combustion sensors used to detect leaks in the liquid hydrogen transfer systems at Kennedy Space Center was developed. A fluidic sensor concept, based on the principle that the frequency of a fluidic oscillator is proportional to the square root of the molecular weight of its operating fluid, was utilized. To minimize sensitivity to pressure and temperature fluctuations, and to make the sensor specific for hydrogen, two oscillators are used. One oscillator operates on sample gas containing hydrogen, while the other operates on sample gas with the hydrogen converted to steam. The conversion is accomplished with a small catalytic converter. The frequency difference is taken, and the hydrogen concentration computed with a simple digital processing circuit. The output from the sensor is an analog signal proportional to hydrogen content. The sensor is shown to be accurate and insensitive to severe environmental disturbances. It is also specific for hydrogen, even with large helium concentrations in the sample gas

Tentative Detection of the Rotation of Eris

We report a multi-week sequence of B-band photometric measurements of the dwarf planet Eris using the {\it Swift} satellite. The use of an observatory in low-Earth orbit provides better temporal sampling than is available with a ground-based telescope. We find no compelling evidence for an unusually slow rotation period of multiple days, as has been suggested previously. A $\sim$1.08 day rotation period is marginally detected at a modest level of statistical confidence ($\sim$97%). Analysis of the combination of the $Swift$ data with the ground-based B-band measurements of \citet{2007AJ....133...26R} returns the same period ($\sim$1.08 day) at a slightly higher statistical confidence ($\sim$99%).Comment: Accepted to Icarus 2008-Aug-19. 19 pages total, including 4 figures and 1 tabl

Towards a genuinely multi-dimensional upwind scheme

Methods of incorporating multi-dimensional ideas into algorithms for the solution of Euler equations are presented. Three schemes are developed and tested: a scheme based on a downwind distribution, a scheme based on a rotated Riemann solver and a scheme based on a generalized Riemann solver. The schemes show an improvement over first-order, grid-aligned upwind schemes, but the higher-order performance is less impressive. An outlook for the future of multi-dimensional upwind schemes is given

THE VALUE OF CLEAN DAIRY AIR: ACCOUNTING FOR ENDOGENEITY AND SPATIALLY CORRELATED ERRORS IN A HEDONIC ANALYSES OF THE IMPACT OF ANIMAL OPERATIONS ON LOCAL PROPERTY VALUES

We study the effect of livestock operations on property values using a hedonic analysis in five Ohio townships. Unlike previous studies, we account for endogenous livestock location variables and spatially correlated errors. Results suggest failure to correct for these problems results in biased estimates of livestock impacts on property values.Land Economics/Use,

THE EFFECTS OF FARMLAND, FARMLAND PRESERVATION AND OTHER NEIGHBORHOOD AMENITIES ON PROXIMATE HOUSING VALUES: RESULTS OF A CONJOINT ANALYSIS OF HOUSING CHOICE

Using stated-preference data from a choice-based conjoint analysis instrument, we estimate willingness to pay for the presence of neighboring land that is dedicated to agricultural use (versus a developed land use) and for the preservation of surrounding farmland as permanent cropland. The data also elucidate how individuals balance the values associated with nearby agricultural land patterns with other key neighborhood characteristics such as neighborhood parks, housing density, commute times, school quality and neighborhood safety. The median respondent from a randomly chosen sample of Columbus, Ohio homeowners was willing to pay $843 annually to avoid immediate conversion of 10 percent of agricultural land within one mile of the house valued in the conjoint experiment while the same respondent was willing to pay$277 annually to preserve the same amount of farmland as permanent cropland. We find provision of neighborhood parks within housing developments to be a strong substitute for farmland preservation.Land Economics/Use,

Women Leaders in the Baltic States: Untying the Double-Bind

Across the post-Soviet region, but particularly in the Baltic states, women executives have gained power in greater numbers and at higher rates than many other regions in the world. This defies existing literature, as these states maintain conservative gender stereotypes while also facing a major security threat from Russia close to their borders. This thesis posits that the increase in women within Baltic legislatures across time creates a political pipeline, or a pool of qualified candidates that makes the election of women to executive power more likely. This is not the only factor, however, as the influence of NATO as a guarantor of Baltic security cannot be understated. Thus, this research finds evidence that NATO’s Article V has provided a security guarantee for the Baltic states, which has resulted in a consensus around security policy. This removes security as a major issue in elections, and lessens the burden of proving security competence from women leaders - an area which often aggravates the effect of stereotypes. If this security consensus is disrupted, however, women face an altered double-bind scenario in which they must balance the maintenance of a positive relationship with NATO/the U.S. while fulfilling their cultural role as women, tied deeply to national survival and independence. Estonia and Lithuania are selected as case studies, which culminate in an examination of current Estonian Prime Minister Kaja Kallas and Lithuanian Prime Minister Ingrida Simonyte

On asymptotic dimension of groups

We prove a version of the countable union theorem for asymptotic dimension and we apply it to groups acting on asymptotically finite dimensional metric spaces. As a consequence we obtain the following finite dimensionality theorems. A) An amalgamated product of asymptotically finite dimensional groups has finite asymptotic dimension: asdim A *_C B < infinity. B) Suppose that G' is an HNN extension of a group G with asdim G < infinity. Then asdim G'< infinity. C) Suppose that \Gamma is Davis' group constructed from a group \pi with asdim\pi < infinity. Then asdim\Gamma < infinity.Comment: Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol1/agt-1-4.abs.htm

An implicit and explicit assessment of morphic resonance theory using Chinese characters

Learning and memory have traditionally been assumed to be solely reliant on cortical functioning. However, the transmission of acquired habits and transgenerational memory effects challenge this assumption. A complementary view is that learning and memory may also be supported by some form of interaction, or resonance, that takes place between the individual and a wider morphic field which contains information that may be able to shape learning and memory. It has been suggested that information from such a morphic field could influence an individual’s ability to respond to an unfamiliar language which has a large number of past speakers. This has been tested using non-Chinese speaking individuals presented with real and decoy Chinese characters. However, the outcomes have been equivocal. Hence, the aim of the current study was to examine and extend this research by utilising and comparing performance from implicit and explicit tasks. The predictions were that participants should implicitly prefer real Chinese characters and explicitly identify real Chinese characters at levels greater than chance. An opportunity sample of 154 participants completed an implicit preference task and an explicit identification task online with task order counterbalanced. In each task participants were shown, in a random order, 12 pairs of characters (one real and one decoy). In the implicit task they were required to identify which of the characters they preferred and in the explicit task they were asked to identify which of the pair was the real character. Measures of belief in psi were also obtained. The results showed that, contrary to the prediction, participants significantly preferred the decoy Chinese characters. There was no difference in explicit identification rates and no correlations between performance and belief in psi. These findings fail to support the idea of morphic resonance and are more parsimoniously accounted for in terms of an aesthetic preference for the decoy characters