Consider the gradient map associated to any non-constant homogeneous polynomial f ∈ C[x0, . . . , xn] of degree d, defined by φf = grad(f) : D(f) → P , (x0 : . . . : xn) → (f0(x) : . . . : fn(x)) whereD(f) = {x ∈ P; f(x) 6= 0} is the principal open set associated to f and fi = ∂f ∂xi . This map corresponds to polar Cremona transformations. In Proposition 3.4 we give a new lower bound for the de...

[1] The previous discovery of extensive deposits of hydrated minerals in Olympia Planum in the north polar region of Mars by the Mars Express OMEGA instrument raises important questions about the origin and subsequent redistribution of these hydrated minerals. Here we present a new map of the distribution of hydrated minerals within the north polar region of Mars by applying both standard and n...

Different software tools for quantification of myocardial perfusion SPECT (MPS) studies are routinely used. Several perfusion parameters can be computed automatically.  Interpretation of the MPS should start with visual inspection of the rotating planar images, visual analysis of reconstructed SPECT slices and then quantitative analysis to confirm the visual impression. Quantification should be...

Persistent organic pollutants (POPs) are widespread compounds that accumulating in polar regions canalise through trophic webs. Although several dozens of studies have been carried out in the last decades, the information is generally scattered across a large number of literature sources. This does not allow an efficient synthesis and constraints our understanding on how address future monitori...

in the present work, a modified correlation is presented for the second virial coefficients of both polar and nonpolar fluids based on the corresponding states principle. the second virial coefficients of gaseous polar and non-polar compounds were calculated and compared with experimental data and with other correlations. comparisons with the existing correlations show that the present work is ...

This paper describes a path planning system using combined information from memory and sensors in a egocentric map. This technique enables autonomous mobile robots to use optimal path planning techniques such as the resistive grid. Using an egocentric map solves the self-localisation problem for mobiles robots and facilitates the reading of potential gradients in the resistive grid because the ...

In this paper, we first give a characterization of sub-topical functions with respect to their lower level sets and epigraph. Next, by using two different classes of elementary functions, we present a characterization of sub-topical functions with respect to their polar functions, and investigate the relation between polar functions and support sets of this class of functions. Finally, we obtai...

Introduction: The polar layered deposits of Mars represent potentially important volatile reservoirs and tracers for the planet’s geologically recent climate history. Unlike the north polar cap, the uppermost surface of the bright residual south polar deposit (Fig. 1) is probably composed of carbon dioxide ice [e.g., 1]. It is unknown whether this ice extends through the entire thickness of the...