Mammalian Reovirus M3 Gene Sequences and Conservation of Coiled-Coil Motifs near the Carboxyl Terminus of the μNS Protein

AbstractNucleotide sequences of the mammalian orthoreovirus (reovirus) type 1 Lang and type 2 Jones M3 gene segments were newly determined. The nucleotide sequence of the reovirus type 3 Dearing M3 segment also was determined to compare with a previously reported M3 sequence for that isolate. Comparisons showed Lang and Dearing M3 to be more closely related than either was to Jones M3, consistent with previous findings for other reovirus gene segments. The μNS protein sequences deduced from each M3 segment were shown to be related in a similar pattern as the respective nucleotide sequences and to contain several regions of greater or less than average variability among the three isolates. Identification of conserved methionine codons near the 5′ ends of the Lang, Jones, and Dearing M3 plus strands lent support to the hypothesis that μNSC, a smaller protein also encoded by M3, arises by translation initiation from a downstream methionine codon within the same open reading frame as μNS. Other analyses of the deduced protein sequences indicated that regions within the carboxyl-terminal third of μNS and μNSC from each isolate have a propensity to form α-helical coiled coils, most likely coiled-coil dimers. The new sequences will augment further studies on μNS and μNSC structure and function

All-optical conditional logic with a nonlinear photonic crystal nanocavity

We demonstrate tunable frequency-converted light mediated by a chi-(2) nonlinear photonic crystal nanocavity. The wavelength-scale InP-based cavity supports two closely-spaced localized modes near 1550 nm which are resonantly excited by a 130 fs laser pulse. The cavity is simultaneously irradiated with a non-resonant probe beam, giving rise to rich second-order scattering spectra reflecting nonlinear mixing of the different resonant and non-resonant components. In particular, we highlight the radiation at the sum frequencies of the probe beam and the respective cavity modes. This would be a useful, minimally-invasive monitor of the joint occupancy state of multiple cavities in an integrated optical circuit.Comment: 4 pages, 4 figure

Second-Order Nonlinear Mixing of Two Modes in a Planar Photonic Crystal Microcavity

Polarization-resolved second-harmonic spectra are obtained from the resonant modes of a two-dimensional planar photonic crystal microcavity patterned in a free-standing InP slab. The photonic crystal microcavity is comprised of a single missing-hole defect in a hexagonal photonic crystal host formed with elliptically-shaped holes. The cavity supports two orthogonally-polarized resonant modes split by 60 wavenumbers. Sum-frequency data are reported from the nonlinear interaction of the two coherently excited modes, and the polarization dependence is explained in terms of the nonlinear susceptibility tensor of the host InP.Comment: 7 pages, 8 Postscript figures, to be presented at Photonics West Jan. 2

OXYGEN CONSUMPTION: EFFECT OF LATERAL PEDAL WIDTH VARIATIONS RELATIVE TO Q-ANGLE IN AVID CYCLISTS

Twenty cyclists completed four trials at 50% of maximal effort. Trials were performed at four different lateral widths (0, 20mm, 25mm, and 30mm) by adding a Kneesaver™ pedal spacer between the crank arm and pedal. Each trial lasted five minutes, during which analysis of expired air took place, as well as video analysis for digitizing purposes. The aim of the study was to determine if changing this lateral pedal width affected oxygen consumption and if lateral pedal width changed Q-angle in the cyclists. Statistically width did not affect Q-angle or oxygen consumption, however a significant, but small correlation was found between Q-angle and oxygen consumption

Structural dynamic analysis of the Space Shuttle Main Engine

This structural dynamic analysis supports development of the SSME by evaluating components subjected to critical dynamic loads, identifying significant parameters, and evaluating solution methods. Engine operating parameters at both rated and full power levels are considered. Detailed structural dynamic analyses of operationally critical and life limited components support the assessment of engine design modifications and environmental changes. Engine system test results are utilized to verify analytic model simulations. The SSME main chamber injector assembly is an assembly of 600 injector elements which are called LOX posts. The overall LOX post analysis procedure is shown

A Neutral Hydrogen Self-Absorption Cloud in the SGPS

Using data from the Southern Galactic Plane Survey (SGPS) we analyze an HI self-absorption cloud centered on l = 318.0 deg, b = -0.5 deg, and velocity, v = -1.1 km/s. The cloud was observed with the Australia Telescope Compact Array (ATCA) and the Parkes Radio Telescope, and is at a near kinematic distance of less than 400 pc with derived dimensions of less than 5 x 11 pc. We apply two different methods to find the optical depth and spin temperature. In both methods we find upper limit spin temperatures ranging from 20 K to 25 K and lower limit optical depths ~ 1. We look into the nature of the HI emission and find that 60-70% originates behind the cloud. We analyze a second cloud at the same velocity centered on l = 319 deg and b = 0.4 deg with an upper limit spin temperature of 20 K and a lower limit optical depth of 1.6. The similarities in spin temperature, optical depth, velocity, and spatial location are evidence the clouds are associated, possibly as one large cloud consisting of smaller clumps of gas. We compare HI emission data with 12CO emission and find a physical association of the HI self-absorption cloud with molecular gas.Comment: 33 pages, 17 figures, 5 tables; Accepted for publication in ApJ. A version with higher quality images availabe at http://www.astro.umn.edu/~dkavars/ms.p

In-flight scale/distortion calibration of the Hubble Space Telescope fixed-head star trackers

This paper describes an in-flight scale and distortion calibration procedure that has been developed for the Ball Aerospace Systems Division Fixed-Head Star Trackers (FHST's) used on the Hubble Space Telescope (HST). The FHST is a magnetically focused and deflected imaging sensor that is designed to track stars as faint as m(sub v) = 5.7 over an 8 degree by 8 degree field of view. Raw FHST position measurements are accurate to approximately 200 arcseconds, but this can be improved to 10-15 arcseconds by processing the raw measurements through calibration polynomials that correct for flat field, temperature intensity, and magnetic field effects. The coefficients for these polynomials were initially determined using ground test data. On HST the use of three FHST's is an integral part of the preliminary attitude update procedures required before the acquisition of guide stars for science observations. To this end, FHST-based attitude determination having single-axis errors no worse than 22 arcseconds (1 sigma) is required. In early 1991 it became evident that one of the HST FHST's was experiencing a significant change in its optical scale. By mid-1993 the size of this error had grown to a point that, if not corrected, it would correspond to a maximum position error on the order of 100 arcseconds. Subsequent investigations demonstrated that substantial, uncompensated cubic distortion effects had also developed, the maximum contribution to position errors from the cubic terms being on the order of 30 arcseconds. To ensure accurate FHST-based attitude updates, procedures have been developed to redetermine the FHST scale and distortion calibration coefficients based on in-flight data gathered during normal HST operations. These scale and distortion calibrations have proven very effective operationally, and procedures are in place to monitor FHST calibration changes on a continuing basis

Observation of a stronger-than-adiabatic change of light trapped in an ultrafast switched GaAs-AlAs microcavity

We study the time-resolved reflectivity spectrum of a switched planar GaAs-AlAs microcavity. Between 5 and 40 ps after the switching (pump) pulse we observe a strong excess probe reflectivity and a change of the frequency of light trapped in the cavity up to 5 linewidths away from the cavity resonance. This frequency change does not adiabatically follow the fast-changing cavity resonance. The frequency change is attributed to an accumulated phase change due to the time-dependent refractive index. An analytical model predicts dynamics in qualitative agreement with the experiments, and points to crucial parameters that control future applications.Comment: Discussed effect of probe bandwidth. Included functional forms of n(z) and R(z

Understanding the Spectral Energy Distributions of the Galactic Star Forming Regions IRAS 18314-0720, 18355-0532 & 18316-0602

Embedded Young Stellar Objects (YSO) in dense interstellar clouds is treated self-consistently to understand their spectral energy distributions (SED). Radiative transfer calculations in spherical geometry involving the dust as well as the gas component, have been carried out to explain observations covering a wide spectral range encompassing near-infrared to radio continuum wavelengths. Various geometric and physical details of the YSOs are determined from this modelling scheme. In order to assess the effectiveness of this self-consistent scheme, three young Galactic star forming regions associated with IRAS 18314-0720, 18355-0532 and 18316-0602 have been modelled as test cases. They cover a large range of luminosity ($\approx$ 40). The modelling of their SEDs has led to information about various details of these sources, e.g. embedded energy source, cloud structure & size, density distribution, composition & abundance of dust grains etc. In all three cases, the best fit model corresponds to the uniform density distribution.Comment: AAMS style manuscript with 3 tables (in a separate file) and 4 figures. To appear in Journal of Astronophysics & Astronom