We have shown previously that transmembrane proton gradients can be used to efficiently accumulate biogenic amines [M.B. Bally et al. (1988) Chem. Phys. Lipids 47, 97-107] and doxorubicin [L.D. Mayer, M.B. Bally and P.R. Cullis (1986) Biochim. Biophys. Acta 857, 123-126] to high concentrations within liposomes. To determine the generality of this loading procedure, representative drugs from a v...

Recently, a considerable growth of interest in projected gradient (PG) methods has been observed due to their high efficiency in solving large-scale convex minimization problems subject to linear constraints. Since the minimization problems underlying nonnegative matrix factorization (NMF) of large matrices well matches this class of minimization problems, we investigate and test some recent PG...

A broad experimental survey is made of the properties of spontaneously generated magnetic fluctuations in a large linear device in which the plasma density has different cross-field gradient scales. It includes steep gradients at the plasma–wall edge as well as at an interior plasma–plasma interface, thus phenomena of interest to magnetic fusion research as well as to space plasma physics is il...

Our objective, here, is to generalize our earlier results on the existence of classical convex solution to a free boundary problem with a Bernoullitype boundary gradient condition and with the p-Laplacian as the governing operator. The main theorems of this paper assert that the exterior and the interior free boundary problem with a Bernoulli law, i.e. with a prescribed pressure a(x) on the “fr...

In this paper a variational segmentation model is proposed. It is a generalization of the Chan and Vese model, for the scalar and vector-valued cases. It incorporates extra terms, depending on the image gradient, and aims at approximating the smoothed image gradient norm, inside and outside the segmentation curve, by mean constant values. As a result, a flexible model is obtained. It segments, ...

In the first part of this paper, we prove local interior and boundary gradient estimates for p-harmonic functions on general Riemannian manifolds. With these estimates, following the strategy in recent work of R. Moser, we prove an existence theorem for weak solutions to the level set formulation of the 1/H (inverse mean curvature) flow for hypersurfaces in ambient manifolds satisfying a sharp ...

Boreal wetlands are characterized by a mosaic of plant communities, including forests, shrublands, grasslands, and fens, which are structured largely by changes in topography and water table position. The soil associatedwith these plant communities contain quantitatively and qualitatively different forms of soil organic matter (SOM) and nutrient availability that drive changes in biogeochemical...

where ν is the outward pointing unit normal of ∂Ω, and where cosθ is a given function on ∂Ω. (Thus, in the capillarity problem, we are considering geometrically a function u in Ω̄ whose graph has the prescribed mean curvature H and which meets the boundary cylinder in the prescribed angle θ.) Here, H = H(x,t) is assumed to be a given locally Lipschitz function in Ω×R satisfying the structural co...

Let φ be a convex function on a strictly convex domain Ω ⊂ Rn, n ≥ 1. The corresponding linearized Monge–Ampère equation is trace(ΦD2u) = f , where Φ := det D2φ (D2φ)−1 is the matrix of cofactors of D2φ. We establish interior Hölder estimates for derivatives of solutions to the equation when the function f on the right hand side belongs to Lp(Ω) for some p > n. The function φ is assumed to be s...

Article history: Received 29 August 2008 Accepted 19 November 2009 Available online 12 January 2010 Submitted by V. Mehrmann AMS classification: 65F15 65K05 65K10 65L15