Dvořák [5] gave a bound on the minimum size of a distance r dominating set in the terms of the maximum size of a distance 2r independent set and generalized coloring numbers, thus obtaining a constant factor approximation algorithm for the parameters in any class of graphs with bounded expansion. We improve and clarify this dependence using an LP-based argument inspired by the work of Bansal an...

We study the complexity of inverting many-one, honest, polynomial-time computable onto functions. Asserting that every polynomial-time computable, honest, onto function is invertible is equivalent to the following proposition that we call Q: For all NP machines M that accept , there exists a polynomial-time computable function gM such that for all x, gM(x) outputs an accepting computation of M ...

Many NP-hard graph problems become easier to approximate on planar graphs and their generalizations. (A graph is planar if it can be drawn in the plane (or the sphere) without crossings. For definitions of other related graph classes, see the entry on Bidimensionality (2004; Demaine, Fomin, Hajiaghayi, Thilikos).) For example, maximum independent set asks to find a maximum subset of vertices in...

We study the offline and online versions of the well known problem of scheduling a set of n independent multiprocessor tasks with prespecified processor allocations on a set of identical processors in order to minimize the makespan. Recently, in [13], it has been proven that in the case when all tasks have unit processing time the problem cannot be approximated within a factor of m 1 2 ε, neith...

In a short term prospective study 70 male lead workers performed a series of cognitive tasks on three occasions during an eight month period. Concurrently with the cognitive testing, the concentrations of blood lead, zinc protoporphyrin (ZPP) and urinary aminolaevulinic acid (ALA) were measured. Indicators of lead absorption were stable during the study and each subject was allocated to either ...

In-home fortification of infants with micronutrient powders (MNPs) containing 12.5 mg iron may increase morbidity from infections; therefore, an efficacious low-dose iron-containing MNP might be advantageous. Effects of iron-containing MNPs on infant growth are unclear. We assessed the efficacy of a low-iron MNP on iron status and growth and monitored safety in a randomised, controlled, double-...

OBJECTIVES To test the association between inorganic lead (Pb) exposure, blood pressure, and renal function in South African battery factory workers, with both conventional and newer measures of renal function and integrity. METHODS Renal function measures included serum creatinine, urea, and urate (n = 382). Urinary markers (n = 199) included urinary N-acetyl-beta-D-glucosaminidase (NAG), re...

This is a non-technical survey paper of recent quantum-mechanical discoveries that challenge generally accepted complexity-theoretic versions of the Church{Turing thesis. In particular, building on pi-onering work of David Deutsch and Richard Jozsa, we construct an oracle relative to which there exists a set that can be recognized in Quantum Polynomial Time (QP), yet any Turing machine that rec...

Permission to make copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for proot or commercial advantage and that new copies bear this notice and the full citation on the rst page. Abstracting with credit is permitted. I Preface Complexity Theory is a central eld of Theoretical Computer Science, with a remarkab...

The aim of this study was to estimate the activity of superoxide dismutase (SOD) and catalase in erythrocytes and malondialdehyde (MDA) in plasma of battery manufacturing workers (BMW) of Western Maharashtra (India) who were occupationally exposed to lead (Pb) over a long period of time (about 15 years). This study was also aimed to determine the Pb intoxication resulted in a disturbance of hem...