7,787 research outputs found
Method and apparatus for contour mapping using synthetic aperture radar
By using two SAR antennas spaced a known distance, B, and oriented at substantially the same look angle to illuminate the same target area, pixel data from the two antennas may be compared in phase to determine a difference delta phi from which a slant angle theta is determined for each pixel point from an equation Delta phi = (2 pi B/lambda)sin(theta - alpha), where lambda is the radar wavelength and alpha is the roll angle of the aircraft. The height, h, of each pixel point from the aircraft is determined from the equation h = R cos theta, and from the known altitude, a, of the aircraft above sea level, the altitude (elevation), a', of each point is determined from the difference a - h. This elevation data may be displayed with the SAR image by, for example, quantizing the elevation at increments of 100 feet starting at sea level, and color coding pixels of the same quantized elevation. The distance, d, of each pixel from the ground track of the aircraft used for the display may be determined more accurately from the equation d = R sin theta
Natural Gas and Inequality in Bolivia after Nationalization
The high oil prices and the sharp increases in royalties mean that the natural gas boom in Bolivia has become very important for the economy. This paper uses a Computable General Equilibrium (CGE) model to assess the impacts of this boom on key macroeconomic variables as well as the distribution of incomes in the society. From a macroeconomic perspective, the natural gas boom is a blessing, adding around 1 percentage point to GDP growth rates for at least a decade, and sharply increasing government revenues available for public spending and investment. However, the poorest segments of the population (rural small-holders and urban informals) suffer actual reductions in their real incomes, compared to the counterfactual scenario without the gas boom. This means that the natural gas boom not only causes an increase in inequality but also an increase in poverty. The paper finishes with some policy recommendations on how to counteract the negative side effects of the natural gas boom.Natural Gas, Inequality, CGE model, Bolivia
Number of walks and degree powers in a graph
This note deals with the relationship between the total number of -walks
in a graph, and the sum of the -th powers of its vertex degrees. In
particular, it is shown that the the number of all -walks is upper bounded
by the sum of the -th powers of the degrees
Stable Determination of the Electromagnetic Coefficients by Boundary Measurements
The goal of this paper is to prove a stable determination of the coefficients
for the time-harmonic Maxwell equations, in a Lipschitz domain, by boundary
measurements
Control of Glycolytic Flux by AMPK and p53-Mediated Signaling Pathways in Tumor Cells Adapted to Grow at Low pH
Introduction: Tumor cells grow in nutrient and oxygen deprived microenvironments and adapt to the suboptimal growth conditions by altering metabolic pathways. This adaptation process characteristically results in a tumor phenotype that displays anaerobic glycolysis, chronic acidification and aggressive tumor characteristics. Understanding the tumor cell reaction to the microenvironment is a critical factor in predicting the tumor response to hyperthermia. The glucose regulatory molecule, 6-Phosphofructo-2-Kinase/Fructose-2,6-Biphosphatase Isoform-3 (PFKFB3), is a bifunctional enzyme central to glycolytic flux and downstream of the metabolic stress sensor AMP-activated protein kinase (AMPK), which has been shown to activate an isoform of Phosphofructokinase (PFK-2).
Society for Thermal Medicine Annual Meeting April 23-26, Clearwater Beach, FL
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