In 1957 W.M. Hirsch conjectured that every d-polytope with n facets has edge-diameter at most n ? d. Recently Holt and Klee constructed polytopes which meet this bound for a number of (d; n) pairs with d 13 and for all pairs (14; n). These constructions involve a judicious use of truncation, wedging, and blending on polytopes which already meet the Hirsch bound. In this paper we extend these te...

We develop two q-analogues of the previously defined poly-Stirling numbers of the first and second kinds. We also develop the corresponding q-rook theory models to give combinatorial interpretations to these numbers.

We investigate the expressive limitations of FO +poly extended with a connectivity predicate, Conn.

Dust from thermal processes may catalytically enhance the formation of chlorinated aromatic compounds under oxygen-rich conditions. The activities of two dust samples from electric arc furnaces and one from iron ore-based steelmaking (oxygen converter) were investigated in a laboratory experiment. The dust samples were heated at 300 degrees C for 2 h in an air atmosphere. The concentrations of ...

There are several basic principles that apply to the clinicopathologic syndrome produced by polychlorinated biphenyls (PCBs). They are as follows: The degree of halogenation and position of the halogen atoms determine the potency of PCB, PBB, CDD, CDF and CN; in a given species of animals, the clinicopathologic syndrome induced by PCB is comparable to that induced by polybrominated biphenyls (P...

Chlorinated dioxins are the group of environmental pollutants consisting of 210 chlorinated dibenzo-p-dioxins and dibenzofurans. They are highly toxic and persistent. They are lipophilic and can easily biomagnify in the food chain, hence posing a serious threat to human health. The daily consumption of low-level contaminated food, mainly of animal origin, leads to the accumulation of dioxins in...

The holy grail for computer science has been trying to somehow show that P 6= NP . And another problem that is equally intriguing is to show that NP * P/poly, trying to find circuit (over ∧,∨,¬) lower bounds for problems in NP . But suppose we were able to drop the ¬ gate from the basis, we would be able to compute only monotone functions, but can we show some monotone circuit lower bounds for ...

Concentrations of 6 organophosphate esters (OPEs) were determined in 60 indoor (ID) and outdoor (OD) dust samples collected from 20 homes Basrah, Iraq. From each home, two ID collected, one elevated surfaces (ESD) the floor (FD) living room; while OD front yard same house. Total Σ6OPEs concentrations ranged between 681 17900 ng/g with median 5950, 3590 1550 ESD, FD samples, respectively. Chlori...