By w, we denote the space of all real or complex valued sequences. If x ∈ w, then we simply write x xk instead of x xk ∞ k 1. Also, we will use the conventions that e 1, 1, . . . . Any vector subspace of w is called a sequence space. We will write l∞, c, and c0 for the sequence spaces of all bounded, convergent, and null sequences, respectively. Further, by lp 1 ≤ p < ∞ , we denote the sequence...

Salmonella enterica subsp. enterica serovar Typhimurium is a leading cause of food-borne salmonellosis in the United States. The number of antibiotic-resistant isolates identified in humans is steadily increasing, suggesting that the spread of antibiotic-resistant strains is a major threat to public health. S Typhimurium is commonly identified in a wide range of animal hosts, food sources, and ...

We examine portage sites in the U.S. South, Mid-Atlantic, and Midwest, including those on the fall line, a geomorphologic feature in the southeastern U.S. marking the final rapids on rivers before the ocean. Historically, waterborne transport of goods required portage around the falls at these points, while some falls provided water power during early industrialization. These factors attracted ...

A natural rsbU mutant of Staphylococcus aureus, unable to activate the alternative transcription factor s via the RsbU pathway and therefore forming unpigmented colonies, produced first-step teicoplanin-resistant mutants upon selection for growth in the presence of teicoplanin, of which the majority were of an intense orange color. By using an asp23 promoter-luciferase fusion as an indicator, t...

A line in [n]d is a set {x(1), . . . , x(n)} of n elements of [n]d such that for each 1 6 i 6 d, the sequence x i , . . . , x (n) i is either strictly increasing from 1 to n, or strictly decreasing from n to 1, or constant. How many lines can a set S ⊆ [n]d of a given size contain? One of our aims in this paper is to give a counterexample to the Ratio Conjecture of Patashnik, which states that ...