Laboratory studies, analysis, and interpretation of the spectra of hydrocarbons present in planetary atmospheres including cyanoacetylene, acetylene, propane, and ethane

Combining broadband Fourier transform spectrometers (FTS) from the McMath facility at NSO and from NRC in Ottawa and narrow band TDL data from the laboratories with computational physics techniques has produced a broad range of results for the study of planetary atmospheres. Motivation for the effort flows from the Voyager/IRIS observations and the needs of Voyager analysis for laboratory results. In addition, anticipation of the Cassini mission adds incentive to pursue studies of observed and potentially observable constituents of planetary atmospheres. Current studies include cyanoacetylene, acetylene, propane, and ethane. Particular attention is devoted to cyanoacetylen (H3CN) which is observed in the atmosphere of Titan. The results of a high resolution infrared laboratory study of the line positions of the 663, 449, and 22.5/cm fundamental bands are presented. Line position, reproducible to better than 5 MHz for the first two bands, are available for infrared astrophysical searches. Intensity and broadening studies are in progress. Acetylene is a nearly ubiquitous atmospheric constituent of the outer planets and Titan due to the nature of methane photochemistry. Results of ambient temperature absolute intensity measurements are presented for the fundamental and two two-quantum hotband in the 730/cm region. Low temperature hotband intensity and linewidth measurements are planned

A Spectral Atlas of the Nu(sub 12) Fundamental of (13)C(12)CH6 in the 12 Micron Region

The recent discovery of the minor isotopomer of ethane, (13)C(12)CH6, in the planetary atmospheres of Jupiter and Neptune, added ethane to the molecules which can be used to determine isotopic (12)C(12)C ratios for the jovian planets. The increased spectral resolution and coverage of the IR and far-IR instruments to be carried on the Cassini mission to Saturn and Titan may enable the detection of the minor isotopomer. Accurate frequency and cross-section measurements of the nu(sub 12) fundamental under controlled laboratory condition are important to interpret current and future planetary spectra. High resolution spectra of the minor isotopomer (13)C(12)CH6 have been recorded in the 12.2 micron region using the Kitt Peak Fourier Transform (FTS) and the Goddard Tunable Diode Laser spectrometer (TDL). In a global fit to 19 molecular constants in a symmetric top Hamiltonian, transition frequencies of the nu(sub 12) fundamental ranging up to J=35 and K=20 have been determined with a standard deviation of less than 0.0005 cm(exp -1). From selected line intensity measurements, a vibrational dipole moment for the nu(sub 12) fundamental has been derived. Observed and calculated spectra covering the region from 740 cm(exp -1) and to 910 cm(exp -1) are presented. A compilation of transition frequencies, line intensities, and lower state energies are included for general use in the astronomical community

Gene Expression Profile of Neuronal Progenitor Cells Derived from hESCs: Activation of Chromosome 11p15.5 and Comparison to Human Dopaminergic Neurons

BACKGROUND: We initiated differentiation of human embryonic stem cells (hESCs) into dopamine neurons, obtained a purified population of neuronal precursor cells by cell sorting, and determined patterns of gene transcription. METHODOLOGY: Dopaminergic differentiation of hESCs was initiated by culturing hESCs with a feeder layer of PA6 cells. Differentiating cells were then sorted to obtain a pure population of PSA-NCAM-expressing neuronal precursors, which were then analyzed for gene expression using Massive Parallel Signature Sequencing (MPSS). Individual genes as well as regions of the genome which were activated were determined. PRINCIPAL FINDINGS: A number of genes known to be involved in the specification of dopaminergic neurons, including MSX1, CDKN1C, Pitx1 and Pitx2, as well as several novel genes not previously associated with dopaminergic differentiation, were expressed. Notably, we found that a specific region of the genome located on chromosome 11p15.5 was highly activated. This region contains several genes which have previously been associated with the function of dopaminergic neurons, including the gene for tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis, IGF2, and CDKN1C, which cooperates with Nurr1 in directing the differentiation of dopaminergic neurons. Other genes in this region not previously recognized as being involved in the functions of dopaminergic neurons were also activated, including H19, TSSC4, and HBG2. IGF2 and CDKN1C were also found to be highly expressed in mature human TH-positive dopamine neurons isolated from human brain samples by laser capture. CONCLUSIONS: The present data suggest that the H19-IGF2 imprinting region on chromosome 11p15.5 is involved in the process through which undifferentiated cells are specified to become neuronal precursors and/or dopaminergic neurons

DECONVOLUTION OF HIGH RESOLUTION SPECTRA - TESTS OF THE METHOD

$^{1}$P. A. Jannson, R. H, Hunt, and E. K. Plyler, J. Opt. Soc. Am. 60, 596 (1970).Author Institution: UTMSL, Molecular Spectroscopy Laboratory, Department of Physics and Astronomy, The University of TennesseeExtensive tests of the Jannson deconvolution $method^{1}$ have been carried out. Modifications to the basic Jannson deconvolution program have been made and a detailed study of the deconvolution processes has been carried out. Utilization of the deconvolution process for both line position studies and line shape studies will be discussed. Examples will be presented including tests which are definitive in the sense that a minimum set of assumptions are made in interpretation of test results

Image Restoration and Super-Resolution by Novel Applications of a Neural Network

. A new instrument paradigm is proposed based on the discovery of a method to determine a robust inverse point spread function for a scientific observing instrument modeled as a linear system. As a result of this discovery, it is possible to contemplate an instrumental extension which results in the recovery of a major portion of lost resolution due to the blurring effects of the PSF. Implementation of the instrumental extension and the resulting resolution enhancement is independent of prior knowledge of or access to the observed data. The method is applied to HST images as well as several one dimensional spectral data sets. Results of HST recoveries are compared to Richardson-Lucy recoveries. 1. Introduction All scientific instruments share a common basis when viewed as a linear system. An observing system I , for example, has an input \Theta, and an output D, a response (or point spread function) p, and additive noise n, as represented in Eq. 1: \Theta \Gamma! I(p) \Gamma! D + n (..

DEVELOPMENT OF A NEAR INFRARED-VISIBLE SPECTROPHOTOMETER AT UTMSL

Author Institution: Molecular Spectroscopy Laboratory, Department of Physics and Astronomy University of Tennessee, KnoxvilleA high resolution spectrometer has been designed to operate in the wavelength region spanning the near infrared through the visible. The monochromator configuration is a 1 1/4 meter Ebert-Fastie. The grating is a Bausch and Lomb $5 \times 10$ inch, 316 groove per millimeter echelle driven by a programmable stepping drive. A Perkin Elmer Model 112 spectrometer equipped with a $CaF_{2}$ prism has been modified to act as a predisperser. The sample section follows the monochromator so that only the highly dispersed light excites the sample gas. An interesting feature of the sampling section is the method of double beaming. A beam flipping mirror shifts the sample beam through two paths to a single detector. The signal from the detector [lead sulphide or photomultiplier] is amplified and digitized by an $A/D$ converter and then routed by a PDP-11 computer system to a storage buffer. Design features and performance will be discussed

DESIGN AND OPERATION OF THE UTMSL DATA ACQUISITION, INSTRUMENTAL CONTROL AND INTERACTIVE ANALYSIS SYSTEM

Author Institution: Molecular Spectroscopy Laboratory, Department of Physics and Astronomy University of Tennessee, KnoxvilleAn in-house custom designed data acquisition, instrument control and interactive analysis system has been integrated into the molecular spectroscopy laboratory. The system provides data acquisition and instrumental control for both high resolution spectrometers in the laboratory. Real time digital filtering as well as programmed control of the spectrometers has increased data acquisition rates. Thus the state of the art lifetime of the instruments has effectively been extended by increasing the quantity of data which may be obtained during actual instrumental state of the art lifetime. In addition, the interactive measurement and analysis capabilities are designed to reduce the difficulty and time lapse normally encountered in the labor intensive phase of measurement and analysis of very high resolution spectral data. The data acquisition and control system spools data from a maximum of four infrared detectors and controls up to 48 instruments functions. Eight additional analog sense lines (A/D) and eight analog control lines (D/A) are provided. These lines are used for prism predisperser control, plotting, etc. Real time data display is available on a closed circuit television system; interactive measurement and preliminary analysis capability is provided by a light pen interactive graphic display. Bulk storage is available on magnetic tape and disc systems and spooling of jobs for the local batch processor facility is accomplished using an industry compatible tape system