A pseudo-boolean constraint (PB-constraint) is a linear inequality with 0-1 variables and integer coefficients. Search problems can be modeled as sets of PB-constraints, so that, solutions to a set of PB-constraints map to solutions of the search problem. An optimization problem can be modeled using a set of PB-constraints along with an optimization statement over a set of 0-1 variables. Pseudo...

The addition of lead salts to phosphate-containing Chlamydomonas reinhardtii media caused precipitation of Pb(3)(PO(4))(2), effectively removing phosphate from solution. The effect of Pb(2+) on growth of Chlamydomonas in liquid cultures depended strictly on the ratio of the equivalents of Pb(2+) to phosphate present. When the amount of Pb(2+) approached equivalency with phosphate, cell growth w...

Waterbird feces (mainly mallard Anas platyrhynchos and coot Fulica atra) were collected from four wetlands in Southern Spain in the field or during capture (n = 558 and n = 59, respectively) to study lead (Pb) shot ingestion. Lead and aluminum (Al) concentrations along with Pb isotope signatures were used to identify sources of Pb exposure. The profile and concentrations of porphyrins and biliv...

The role of phytochelatins (PC(n), metal-binding oligopeptides with the general structure (γGlu-Cys)(n)-Gly (n = 2-11) in metal detoxification is assumed to be based on immobilization of metals, which prevents binding of metals to important biomolecules. Although induction of phytochelatin synthesis has often been observed in algae upon exposure to metals, direct evidence for binding of the ind...

Natural Pb-isotope variability in the oceans encodes information about the sources of continental material to the oceans, about ocean circulation, and about Pb removal. In order to use this information, we must understand the natural cycle of Pb in the oceans, which is overprinted by large anthropogenic input. In this study we use Pb, which has not been significantly anthropogenically perturbed...

The risk of Pb contaminated soil after treatment with different remediation techniques was assessed. Soil vitrification (microwaves) reduced Pb orally available from the stomach and intestinal phase measured by a physiologically based extraction test. Solidification of Pb (Slovakite) did not reduce the concentration of orally available Pb and increased the Pb uptake by Thlaspi goesingens for 2-...

The aim of this study was to evaluate the aforementioned chemical elements in tibial plateau samples obtained during knee arthroplasty. The gender-specific analysis of chemical element levels in the bone samples revealed that there were statistically significant differences in the concentration of Pb and Se/Pb ratio. The contents of elements in the tibial plateau in the patients with osteoarthr...

The natural background concentration of lead (Pb) in soils in the United States ranges from 10 to 700 ppm, with an average of 20 ppm (Demayo et al., 1982). However, as a result of anthropogenic activities, soils may be contaminated with elevated levels of Pb. For example, gasoline combustion releases Pb into the atmosphere, and this Pb can be deposited· onto roadside soils. 1,225 ppm Pb ~s note...