Accuracy of laser measurements improved by pulse autocorrelator electronic system

Pulse autocorrelator electronic system discriminates between the dispersion effect of a disturbed laser signal and background noise by detecting multipath arrivals of Gaussian-shaped signal pulses. The autocorrelation function is time-dependent and can be determined by integrating the product of a received pulse and its delayed replicas

Development of monitoring techniques by acoustical means for mechanical checkouts Final report, 15 May - 30 Sep. 1965

Automated pattern recognition devices using sonic signature data for detecting S3D and F-1 engine valve malfunction

A study of laser wave scattering due to refractive index perturbations in the propagating medium Final report, 5 Oct. 1965 - 15 Aug. 1966

Data recording and processing systems for GT-7 LASER communicator experiment - laser wave scattering due to refractive index perturbations in propagating mediu

A role for TSPO in mitochondrial Ca2+ homeostasis and redox stress signaling

The 18 kDa translocator protein TSPO localizes on the outer mitochondrial membrane (OMM). Systematically overexpressed at sites of neuroinflammation it is adopted as a biomarker of brain conditions. TSPO inhibits the autophagic removal of mitochondria by limiting PARK2-mediated mitochondrial ubiquitination via a peri-organelle accumulation of reactive oxygen species (ROS). Here we describe that TSPO deregulates mitochondrial Ca2+ signaling leading to a parallel increase in the cytosolic Ca2+ pools that activate the Ca2+-dependent NADPH oxidase (NOX) thereby increasing ROS. The inhibition of mitochondrial Ca2+ uptake by TSPO is a consequence of the phosphorylation of the voltage-dependent anion channel (VDAC1) by the protein kinase A (PKA), which is recruited to the mitochondria, in complex with the Acyl-CoA binding domain containing 3 (ACBD3). Notably, the neurotransmitter glutamate, which contributes neuronal toxicity in age-dependent conditions, triggers this TSPO-dependent mechanism of cell signaling leading to cellular demise. TSPO is therefore proposed as a novel OMM-based pathway to control intracellular Ca2+ dynamics and redox transients in neuronal cytotoxicity

Faster than Fiber: Advantages and Challenges of Leo Communications Satellite Systems

Low Earth Orbit (LEO) communications satellite systems are emerging as attractive alternatives to the Geostationary Earth Orbit (GEO) systems. GEO satellites have largely dominated the commercial and government communications satellite systems for telecommunications services since the early 1960's. A principal driver behind the move to LEO satellites is the competition to long propagation delay geostationary orbit satellite systems created by rapid expansion of short propagation delay terrestrial land and undersea fiber optic cable links for national and global connectivity. Communication paths over LEO satellites can have shorter propagation delay than terrestrial fiber. This because the speed of electromagnetic wave propagation via LEO satellites is 50% greater than that of light in fiber optic cable. This fact eliminates the long propagation delay property that has become synonymous with GEO communications satellite system. Other drivers are the use of small portable and hand-held earth terminals and the promise of low launch cost of small satellites to low earth orbits. The paper expands on the properties that promise to make LEO communications satellite systems the choice of the future

Satellites in the National Information Infrastructure

The public discussion on the National Information Infrastructure (NII) has bee wide ranging and lacking in consensus as to the nature of the proposed NII itself. This paper in acknowledgment of the national policy origins of the NII debate begins with relevant remarks by President Clinton in his State of the Union Address. It defines an initial working definition of the NII based on the President's challenge. It then provides some clarification to the discussion in terms of planning horizon, subscriber transport services and transport media. The working definition is further developed to incorporate the type of traffic the NII will be expected to support following a discussion of an emerging desktop computing imperative. From this implications are drawn as to the feasibility of the so called fiber solution and an argument made that in the evolution of the current infrastructure to the future NII satellites offer the best solution for a timely manifestation of the vision

Coupled Numerical Analysis of Variations in the Capacity of Driven Energy Piles in Clay

Energy piles are an emerging alternative for the reduction of energy consumption to heat and cool buildings. Most of the research to date has focused on thermodynamic properties or axial and radial stress and strain of piles. This paper focuses on the effects of temperature fluctuation on the capacity of driven energy piles in clayey soils. Consolidation of clay surrounding driven piles affects the pile capacity (i.e., set up in clay). The heating and cooling periods of energy piles can create the excess pore-water pressure (EPWP, ue) or relax the existing one (e.g., due to pile driving or previous thermal loads) in clayey soils (due to the contraction and expansion of water) affecting the pile capacity. In the meantime, the thermal expansion and contraction of the pile also generate or relax the EPWP in the soil, which can be computed using the cavity-expansion theory. This paper studies the resulting changes in the pile capacity due to the daily and seasonal thermal cycles. The results show that thermal cycles in an energy pile can cause a decrease in the pile capacity leading to a delay in reaching the capacity after a complete clay set up

Hybrid Network Architectures; A Framework for Comparative Analysis

The Global Information Infrastructure of the future will include a great variety of heterogeneous, seamlessly interconnected networks. There are strong variety of heterogeneous, seamlessly interconnected networks. There are strong technical and economic reasons predicating the emergence of these hybrid networks which will include many diverse terrestrial (tethered or wireless) and satellite networks in an interoperating configuration. This paper critically analyzes the basis for these new architectures and examines the various possibilities that will emerge in various phases in the future. A summary view is presented for these emerging hybrid architectures, the alternative components and subsystems available and the trade-offs that must be considered. The role of satellites is carefully analyzed and several conclusions are drawn. This paper will present a summary of the work and views of the Center for Satellite and Hybrid Communication Networks todate, in this important area. Specific design and performance evaluation tools being developed will also be described

Human Amniocytes Are Receptive to Chemically Induced Reprogramming to Pluripotency

Restoring pluripotency using chemical compounds alone would be a major step forward in developing clinical-grade pluripotent stem cells, but this has not yet been reported in human cells. We previously demonstrated that VPA_ AFS cells, human amniocytes cultivated with valproic acid (VPA) acquired functional pluripotency while remaining distinct from human embryonic stem cells (hESCs), questioning the relationship between the modulation of cell fate and molecular regulation of the pluripotency network. Here, we used single-cell analysis and functional assays to reveal that VPA treatment resulted in a homogeneous population of self-renewing non-transformed cells that fulfill the hallmarks of pluripotency, i.e., a short G1 phase, a dependence on glycolytic metabolism, expression of epigenetic modifications on histones 3 and 4, and reactivation of endogenous OCT4 and downstream targets at a lower level than that observed in hESCs. Mechanistic insights into the process of VPA-induced reprogramming revealed that it was dependent on OCT4 promoter activation, which was achieved independently of the PI3K (phosphatidylinositol 3-kinase)/ AKT/ mTOR (mammalian target of rapamycin) pathway or GSK3 beta inhibition but was concomitant with the presence of acetylated histones H3K9 and H3K56, which promote pluripotency. Our data identify, for the first time, the pluripotent transcriptional and molecular signature and metabolic status of human chemically induced pluripotent stem cells