Signal processor architecture for backscatter radars

Real time signal processing for backscatter radars which requires computational throughput and I/O rates is discussed. The operations that are usually performed in real time are highly repetitive simple accumulations of samples or of products of samples. The control logic does not depend on the values of the data and general purpose computers are not required for the initial high speed processing. The implications of these facts on the architectures of preprocessors for backscatter radars are explored and applied to the design of the Radar Signal Compender

Ionospheric research - Diurnal variation of the neutral temperature profile at Arecibo from incoherent scatter measurements and its relevance to the 1400 hour density maximum

Diurnal variation of neutral temperature profile at Arecibo from incoherent scattering measurements and its revelance to 1400 hour density maximu

Amygdala reactivity predicts adolescent antisocial behavior but not callous-unemotional traits.

Recent neuroimaging studies have suggested divergent relationships between antisocial behavior (AB) and callous-unemotional (CU) traits and amygdala reactivity to fearful and angry facial expressions in adolescents. However, little work has examined if these findings extend to dimensional measures of behavior in ethnically diverse, non-clinical samples, or if participant sex, ethnicity, pubertal stage, and age moderate associations. We examined links between amygdala reactivity and dimensions of AB and CU traits in 220 Hispanic and non-Hispanic Caucasian adolescents (age 11-15; 49.5% female; 38.2% Hispanic), half of whom had a family history for depression and thus were at relatively elevated risk for late starting, emotionally dysregulated AB. We found that AB was significantly related to increased right amygdala reactivity to angry facial expressions independent of sex, ethnicity, pubertal stage, age, and familial risk status for depression. CU traits were not related to fear- or anger-related amygdala reactivity. The present study further demonstrates that AB is related to increased amygdala reactivity to interpersonal threat cues in adolescents, and that this relationship generalizes across sex, ethnicity, pubertal stage, age, and familial risk status for depression

Endophytic Agrobacterium in crown gall-resistant and -susceptible Vitis genotypes

Several methods were used to study endophytic colonization of Vitis genotypes by Agrobacterium vitis (AV). AV was seldom detected except at inoculated sites, indicating little systemic movement of the bacterium under the conditions of these experiments. AV populations at inoculated sites were evaluated for 10 months following inoculation of crown gall-resistant and -susceptible genotypes. Two months after inoculation, V. amurensis selections had significantly smaller populations than V. vinifera (Cabernet Sauvignon) or V. riparia x V. rupestris (C3309). All crown gall-resistant genotypes had significantly lower populations than Cabernet Sauvignon 10 months after inoculation. Examination of vines one year after inoculation indicated that AV populations were much higher at inoculated sites when crown galls developed. However, even when no galls were apparent, Cabernet Sauvignon had significantly higher AV populations than V. amurensis 689 (6-fold higher) and C3309 (70-fold higher). Crown gall-resistant genotypes appear to support lower populations of AV than the crow gall-susceptible Cabernet Sauvignon. Freezing followed by a two-day incubation significantly increased recovery of Agrobacterium using vascular fluid displacement in naturally-infected and artifically-inoculated vines and therefore increased the sensitivity of indexing for AV in grapevines

Transformation of crown gall resistant and susceptible Vitis genotypes by Agrobacterium vitis

Transformation of crown gall-susceptible and -resistant Vitis genotypes by Agrobacterium vitis strain CG49 was studied using uidA (GUS) in the p35SGUSINT construct. When greenhouse-grown material propagated through tissue culture was inoculated with CG49(p35SGUSINT) in vitro, the highly crown gall-susceptible V. vinifera Cabernet Sauvignon displayed GUS activity on 53 % of inoculated explants vs. 5 % for the resistant V. amurensis and 0 % for the resistant Couderc 3309. Response of Cabernet Sauvignon suggested a strong effect of shoot polarity on transformation. Inoculation of basal vs. apical explant surface in Cabernet Sauvignon indicated transformation in 88 % of basal inoculated explants with no transformation from apical inoculation. Basal inoculations indicated no transformation of V. amurensis and transformation in 10 % of Couderc 3309 explants. Inoculation of intact plants with CG49(p35SGUSINT) produced GUS-positive sites at 56 % of inoculated sites in Cabernet Sauvignon, 10 % of V. amurensis inoculated sites and 9 % of Couderc 3309 inoculated sites. Resistance to crown gall in these genotypes appears to be due to reduced susceptibility to transformation by A. vitis rather than post-transformation phenomena. These studies were complicated by production of GUS-positive spots from in vitro inoculations using wild-type CG49. Resident microorganisms producing b-glucuronidase may proliferate after tissue degradation by A. vitis-induced cell disruption. Use of in vitro internodal explants from tissue culture-propagated vines greatly reduced GUS expression from control CG49 inoculations and these were readily distinguished (by appearance and location) from GUS-positive spots resulting from transformation with uidA

Lattice-dynamics of a Disordered solid-solid Interface

Generic properties of elastic phonon transport at a disordered interface are studied. The results show that phonon transmittance is a strong function of frequency and the disorder correlation length. At frequencies lower than the van Hove singularity the transmittance at a given frequency increases as the correlation length decreases. At low frequencies, this is reflected by different power-laws for phonon conductance across correlated and uncorrelated disordered interfaces which are in approximate agreement with perturbation theory of an elastic continuum. These results can be understood in terms of simple mosaic and two-colour models of the interface.Comment: 17 pages, 5 figures, submitted to PR

Middle Atmosphere Response to Different Descriptions of the 11-Year Solar Cycle in Spectral Irradiance in a Chemistry-Climate Model

The 11-year solar cycle in solar spectral irradiance (SSI) inferred from measurements by the SOlar Radiation & Climate Experiment (SORCE) suggests a much larger variation in the ultraviolet than previously accepted. We present middle atmosphere ozone and temperature responses to the solar cycles in SORCE SSI and the ubiquitous Naval Research Laboratory (NRL) SSI reconstruction using the Goddard Earth Observing System chemistry-climate model (GEOS CCM). The results are largely consistent with other recent modeling studies. The modeled ozone response is positive throughout the stratosphere and lower mesosphere using the NRL SSI, while the SORCE SSI produces a response that is larger in the lower stratosphere but out of phase with respect to total solar irradiance above 45 km. The modeled responses in total ozone are similar to those derived from satellite and ground-based measurements, 3-6 Dobson Units per 100 units of 10.7-cm radio flux (F10.7) in the tropics. The peak zonal mean tropical temperature response 50 using the SORCE SSI is nearly 2 K per 100 units 3 times larger than the simulation using the NRL SSI. The GEOS CCM and the Goddard Space Flight Center (GSFC) 2-D coupled model are used to examine how the SSI solar cycle affects the atmosphere through direct solar heating and photolysis processes individually. Middle atmosphere ozone is affected almost entirely through photolysis, whereas the solar cycle in temperature is caused both through direct heating and photolysis feedbacks, processes that are mostly linearly separable. Further, the net ozone response results from the balance of ozone production at wavelengths less than 242 nm and destruction at longer wavelengths, coincidentally corresponding to the wavelength regimes of the SOLar STellar Irradiance Comparison Experiment (SOLSTICE) and Spectral Irradiance Monitor (SIM) on SORCE, respectively. A higher wavelength-resolution analysis of the spectral response could allow for a better prediction of the atmospheric response to arbitrary SSI variations

Geologic Evaluation of Critical Production Parameters for Coalbed Methane Resources: Part 1, San Juan Basin

The Fruitland Formation in the San Juan Basin is the major producer of coalbed methane in the Western U.S. Forty-three to forty-nine Tcf of methane occur in 245 billion short tons of Fruitland coal at depths between 400 and 4,200 ft. Thickest Fruitland coal seams trend northwest and occur in the northern part of the basin, northeast of a syndepositional, structural hinge line; they occur in coastal plain facies southwest of Pictured Cliffs barrier/strandplain sandstones. South of the hinge line, northeast-trending coal seams occur in floodplain facies between northeast-trending Fruitland fluvial systems. Face cleat trends in Fruitland coal seams are predominantly northeast in the southern two-thirds of the basin and northwest but variable in the northern third. Suggested targets for enhanced coalbed permeability are tectonic fractures and fractures associated with subtle folds. Fruitland Formation waters are evolved meteoric waters; water composition reflects hydrologic setting. Waters in the north-central San Juan Basin have high alkalinity and low chlorinity; waters in the southern part are Na-Cl type. Distribution of low-chloride ground water in the Fruitland Formation in the north-central basin coincides with the overpressured area and with flow patterns inferred from the head map. The Fruitland Formation acts regionally as a single hydrologic unit or homogeneous aquifer, but large pressure gradients locally indicate that Fruitland strata may be hydraulically disconnected and behave at the field scale as compartmentalized aquifers. Hydrologic studies defined reservoir characteristics and permeability boundaries in the Fruitland Formation. Geologic and hydrologic parameters were used to divide the San Juan Basin into areas in which coal beds have similar reservoir characteristics. Coalbed wells have negative declines early in their production history followed by exponential decline rates at less than 5 percent/year. Sandstone wells that exhibit coal-decline behavior probably are producing coalbed methane indirectly from coal seams.Bureau of Economic Geolog

Realistic constraints on the doubly charged bilepton couplings from Bhabha scattering with LEP data

Upper limits on doubly charged bilepton couplings and masses are extracted from LEP data for Bhabha scattering at energy range $\sqrt{s}=183-202$ GeV using standard model program ZFITTER which calculates radiative corrections. We find that $g_{L}^{2}/M_{L}^{2}<O(10^{-5})GeV^{-2}$ at 95% C.L. for scalar and vector bileptons.Comment: 5 pages, 1 EPS figur

Pure O-sequences and matroid h-vectors

We study Stanley's long-standing conjecture that the h-vectors of matroid simplicial complexes are pure O-sequences. Our method consists of a new and more abstract approach, which shifts the focus from working on constructing suitable artinian level monomial ideals, as often done in the past, to the study of properties of pure O-sequences. We propose a conjecture on pure O-sequences and settle it in small socle degrees. This allows us to prove Stanley's conjecture for all matroids of rank 3. At the end of the paper, using our method, we discuss a first possible approach to Stanley's conjecture in full generality. Our technical work on pure O-sequences also uses very recent results of the third author and collaborators.Comment: Contains several changes/updates with respect to the previous version. In particular, a discussion of a possible approach to the general case is included at the end. 13 pages. To appear in the Annals of Combinatoric