Better Bounds on the Accommodating Ratio for the Seat Reservation Problem

In a recent paper [J. Boyar and K.S. Larsen, The seat reservation problem, Algorithmica, 25(1999), 403--417], the seat reservation problem was investigated. It was shown that for the unit price problem, where all tickets have the same price, all "fair" algorithms are at least 1/2-accommodating, while no fair algorithm is more than (4/5 + O(1/k))-accommodating, where k is the number of stations the train travels. In this paper, we design a more dextrous adversary ..

Experimental analysis of some factors affecting parental expenditure and investment in Gasterosteus aculeatus (Gasterosteidae)

Parental investment is the cost of providing parental care. Parental investment was measured in the paternal stickleback, Gasterosteus aculeatus, by comparing future survival (measured indirectly as energy content of the body) and growth of parental and non-parental males. The time taken by parental males to renest was also measured. Male energy content was unaffected after a single parental cycle and no difference in growth rate was detected. Re-nesting was delayed. The effect of stressing parental males by exposing them to potential predators of their offspring and reducing their ration level, was also investigated. Stressed males had reduced energy contents in comparison with unstressed parental males. The time taken by stressed males to re-nest was unaffected. Males on low rations did not fan significantly less than well-fed males. Males exposed to brood predators did fan significantly less than parental males not exposed to brood predators, but the former did spend nearly 60% of their time attacking the predators when present.</p