Living Close to the Edge: Financial Challenges and Tradeoffs for People on Medicare

Profiles the choices and trade-offs Medicare beneficiaries make to cover expenses with limited financial resources, including cutting back on basics and relying on credit cards or help from family, and the effects on medical debts and access to care

Characterizing the dual mixed volume via additive functionals

Integral representations are obtained of positive additive functionals on finite products of the space of continuous functions (or of bounded Borel functions) on a compact Hausdorff space. These are shown to yield characterizations of the dual mixed volume, the fundamental concept in the dual Brunn-Minkowski theory. The characterizations are shown to be best possible in the sense that none of the assumptions can be omitted. The results obtained are in the spirit of a similar characterization of the mixed volume in the classical Brunn-Minkowski theory, obtained recently by Milman and Schneider, but the methods employed are completely different

METROPOLIS : a thematic network in support of precautionary sciences and sustainable development policies

International audienceThe METROPOLIS network was created in July 2002, under the 5th Framework Programme, to respond to the need for an overall, cross-sectoral assessment of the state of the art of measurements and monitoring systems in the environmental field in Europe. The objectives of Metropolis include: - gathering information and knowledge about the problems/shortcomings that we face today in environmental monitoring ; - identifying the fields where research and further work are needed in order to improve the quality and comparability of environmental data across Europe

Consumer Direction of Personal Assistance Services Programs in Medicaid: Insights From Enrollees in Four States

Discusses enrollees' experiences with taking control of their personal care services under the Consumer Direction of Personal Assistance Services program, including recruitment issues, degree of responsibility, and closeness to their care workers

Convex decomposition of U-polygons

AbstractWhen parallel X-rays are considered in any finite set U of directions, switching components with respect to U can be constructed. This is true for U⊂Rn, and also for any finite set of lattice directions. R.J. Gardner raised the problem of looking for a characterization of switching components. In 2001, L. Hajdu and R. Tijdeman gave an answer by proving that a switching component is always the linear combination of switching elements. Though splendid, this result fails to be a characterization theorem inside the class of convex bodies, meaning that the switching element of the linear combination could be not convex even if the switching component is convex. The purpose of this paper is to investigate the problem in the plane, where a convex switching component with respect to U is a U-polygon. We prove that a U-polygon can always be decomposed as a linear sum inside the class of U-polygons

Characterization of hv-Convex Sequences

Reconstructing a discrete object by means of X-rays along a finite set U of (discrete) directions represents one of the main task in discrete tomography. Indeed, it is an ill-posed inverse problem, since different structures exist having the same projections along all lines whose directions range in U. Characteristic of ambiguous reconstructions are special configurations, called switching components, whose understanding represents a main issue in discrete tomography, and an independent interesting geometric problem as well. The investigation of switching component usually bases on some kind of prior knowledge that is incorporated in the tomographic problem. In this paper, we focus on switching components under the constraint of convexity along the horizontal and the vertical directions imposed to the unknown object. Moving from their geometric characterization in windows and curls, we provide a numerical description, by encoding them as special sequences of integers. A detailed study of these sequences leads to the complete understanding of their combinatorial structure, and to a polynomial-time algorithm that explicitly reconstructs any of them from a pair of integers arbitrarily given

On Some Geometric Aspects of the Class of hv-Convex Switching Components

In the usual aim of discrete tomography, the reconstruction of an unknown discrete set is considered, by means of projection data collected along a set U of discrete directions. Possible ambiguous reconstructions can arise if and only if switching components occur, namely, if and only if non-empty images exist having null projections along all the directions in U. In order to lower the number of allowed reconstructions, one tries to incorporate possible extra geometric constraints in the tomographic problem. In particular, the class P of horizontally and vertically convex connected sets (briefly, hv-convex polyominoes) has been largely considered. In this paper we introduce the class of hv-convex switching components, and prove some preliminary results on their geometric structure. The class includes all switching components arising when the tomographic problem is considered in P, which highly motivates the investigation of such configurations. It turns out that the considered class can be partitioned in two disjointed subclasses of closed patterns, called windows and curls, respectively. It follows that all windows have a unique representation, while curls consist of interlaced sequences of sub-patterns, called Z-paths, which leads to the problem of understanding the combinatorial structure of such sequences. We provide explicit constructions of families of curls associated to some special sequences, and also give additional details on further allowed or forbidden configurations by means of a number of illustrative examples