Improved fiberglass-to-metal joint produces lighter stronger fiberglass strut

Axial tension and compression are transmitted between end fittings and fiberglass tube without depending on glass-to-metal bonding, conventional fasteners or combination of these things. Joint design significantly reduces both structural weight of strut and its cross-sectional area

Satellite observations of mesoscale features in lower Cook Inlet and Shelikof Strait, Gulf of Alaska

The Seasat satellite launched in Summer 1978 carried a synthetic aperture radar (SAR). Although Seasat failed after 105 days in orbit, it provided observations that demonstrate the potential to examine and monitor upper oceanic processes. Seasat made five passes over lower Cook Inlet and Shelikof Strait, Alaska, during Summer 1978. SAR images from the passes show oceanographic features, including a meander in a front, a pair of mesoscale eddies, and internal waves. These features are compared with contemporary and representative images from a satellite-borne Advanced Very High Resolution Radiometer (AVHRR) and Coastal Zone Color Scanner (CZCS), with water property data, and with current observations from moored instruments. The results indicate that SAR data can be used to monitor mesoscale oceanographic features

Flight evaluation of advanced control systems and displays on a general aviation airplane

A flight-test program was conducted to determine the effect of advanced flight control systems and displays on the handling qualities of a light twin-engined airplane. A flight-director display and an attitude-command control system, used separately and in combination, transformed a vehicle with poor handling qualities during ILS approaches in turbulent air into a vehicle with good handling qualities. The attitude-command control system also improved the ride qualities of the airplane. A rate-command control system made only small improvements to the airplane's ILS handling qualities in turbulence. Both the rate- and the attitude-command control systems reduced stall warning in the test airplane, increasing the likelihood of inadvertent stalls. The final approach to the point of flare was improved by both the rate- and the attitude-command control systems. However, the small control wheel deflections necessary to flare were unnatural and tended to cause overcontrolling during flare. Airplane handling qualities are summarized for each control-system and display configuration

X-Ray Emission from the Warm Hot Intergalactic Medium

The number of detected baryons in the Universe at z<0.5 is much smaller than predicted by standard big bang nucleosynthesis and by the detailed observation of the Lyman alpha forest at red-shift z=2. Hydrodynamical simulations indicate that a large fraction of the baryons today is expected to be in a ``warm-hot'' (10^5-10^7K) filamentary gas, distributed in the intergalactic medium. This gas, if it exists, should be observable only in the soft X-ray and UV bands. Using the predictions of a particular hydrodynamic model, we simulated the expected X-ray flux as a function of energy in the 0.1-2 keV band due to the Warm-Hot Intergalactic Medium (WHIM), and compared it with the flux from local and high red-shift diffuse components. Our results show that as much as 20% of the total diffuse X-ray background (DXB) in the energy range 0.37-0.925keV could be due to X-ray flux from the WHIM, 70% of which comes from filaments at redshift z between 0.1 and 0.6. Simulations done using a FOV of 3', comparable with that of Suzaku and Constellation-X, show that in more than 20% of the observations we expect the WHIM flux to contribute to more than 20% of the DXB. These simulations also show that in about 10% of all the observations a single bright filament in the FOV accounts, alone, for more than 20% of the DXB flux. Red-shifted oxygen lines should be clearly visible in these observations.Comment: 19 pages, 6 figure

On the finite-size behavior of systems with asymptotically large critical shift

Exact results of the finite-size behavior of the susceptibility in three-dimensional mean spherical model films under Dirichlet-Dirichlet, Dirichlet-Neumann and Neumann-Neumann boundary conditions are presented. The corresponding scaling functions are explicitly derived and their asymptotics close to, above and below the bulk critical temperature $T_c$ are obtained. The results can be incorporated in the framework of the finite-size scaling theory where the exponent $\lambda$ characterizing the shift of the finite-size critical temperature with respect to $T_c$ is smaller than $1/\nu$, with $\nu$ being the critical exponent of the bulk correlation length.Comment: 24 pages, late

Pair Interactions in Red-Faced Warblers

Forty pairs of breeding Red-faced Warblers (Cardellina rubrifrons) were observed in 1992 and 1993 on the Mogollon Rim, Arizona. Intrusions by extra-pair males, interactions between pair members, and other pair interaction behaviors were recorded. The majority of intrusions occurred during the building stage of the nesting cycle. Males responded to intrusions during nest building by decreasing intra-pair distance. Males maintained shorter intra-pair distances by following the female when she initiated movements and by not initiating pair movements themselves. Intra-pair distances were as short or shorter during the incubation period as during nest building, and were shorter during incubation than during egg laying. Males continued to follow females beyond the expected fertile period. Possible explanations for continued mate following include: males guard their mates against predators, males guard their paternity for future nesting attempts, and males respond to extra-pair male intrusions, which continue during incubation

Immunocytochemical localization of glutamate decarboxylase in rat substantia nigra

l-Glutamate decarboxylase (GAD, EC 4.1.1.15), the enzyme which catalyzes the α-decarboxylase of l-glutamate to form γ-aminobutyric acid (GABA), was localized both light and electron microscopically in rat substantia nigra by an immunoperoxidase method. Large amounts of GAD-positive reaction product were seen throughout the substantia nigra in light microscopic preparations, and it appeared to be localized in punctate structures that were apposed to dendrites and somata. Electron microscopic studies revealed that most of the axon terminals in the substantia nigra were filled with GAD-positive reaction product and formed both axodendritic and axosomatic synapses. Many dendrites were extensively surrounded by GAD-positive terminals which most commonly formed symmetric synaptic junctions, although some formed asymmetric synaptic junctions. The results of this investigation are consistent with biochemical, pharmacological and physiological data which have indicated that neurons of the neostriatum and globus pallidus exert a GABA-mediated, postsynaptic inhibition upon the neurons of the substantia nigra. These findings provide another example in the vertebrate central nervous system where Golgi I projection neurons are inhibitory and use GABA as their neurotransmitter. © 1976

Glutamate decarboxylase localization in neurons of the olfactory bulb.

Glutamate decarboxylase (GAD), the enzyme that synthesizes the neurotransmitter gamma-aminobutyric acid (GABA), has been localized in the rat olfactory bulb by immunocytochemical methods with both light and electron microscopy. The light microscopic results demonstrated GAD-positive puncta concentrated in the external plexiform layer and in the glomeruli of the glomerular layer. In addition, GAD-positive reaction product stained the dentrites and somata of granule and periglomerular cells. The electron microscopic observations confirmed the presence of GAD-positive reaction product within granule and periglomerular somata and dendrites. In electron micrographs of the external plexiform layer, the gemmules which arise from the distal dentrites of granule cells were also observed to be filled with reaction product, and these structures corresponded in size and location to the puncta observed in light microscopic preparations. The gemmules were observed to form reciprocal dendrodentritic synaptic junctions with mitral cell dentrites which lacked reaction product. In the glomeruli, GAD-positive reaction product was observed in the dentritic shafts and gemmules of periglomerular cells which also formed reciprocal dendrodentritic synaptic contacts with mitral/tufted cell dentrites. The localization of GAD in known inhibitory neurons of the olfactory bulb supports the case that these local circuit neurons use GABA as their neurotransmitter. The present study demonstrates that GAD molecules located within certain neuronal somata and dentrites can be visualized with antisera prepared against GAD that was purified from synaptosomal fractions of mouse brains. This finding suggests that the lack of GAD staining within somata and dentrites of GABA-ergic neurons noted in previous studies of the cerebellum and spinal cord was probably due to low GAD concentrations, rather than to antigenic differences among GAD molecules located in different portions of the neuron. A striking differences among GAD molecules located in different portions of the neuron. A striking difference between the granule and periglomerular neurons of the olfactory bulb and the neurons of the cerebellum and spinal cord is that the former have presynaptic dentrites while the latter do not. Since GAD-positive reaction product can be detected in the somata and dentrites of GABA-ergic neurons which have presynaptic dentrites, it is suggested that these neurons may differ from other GABA-ergic neurons with respect to either transport or metabolism of GAD

Finite-size scaling of directed percolation above the upper critical dimension

We consider analytically as well as numerically the finite-size scaling behavior in the stationary state near the non-equilibrium phase transition of directed percolation within the mean field regime, i.e., above the upper critical dimension. Analogous to equilibrium, usual finite-size scaling is valid below the upper critical dimension, whereas it fails above. Performing a momentum analysis of associated path integrals we derive modified finite-size scaling forms of the order parameter and its higher moments. The results are confirmed by numerical simulations of corresponding high-dimensional lattice models.Comment: 4 pages, one figur