time. This can be costly. More importantly, even if one had collision detection, a collision could still occur at the receiver. Suppose that station A is transmitting to station B. Suppose also that station C is transmitting to station B. With the so-called hidden terminal problem, physical obstructions in the may prevent A and C from hearing each others transmissions. A second scenario that results in undetectable collisions at the receiver results from the fading of a signal's strength as propagates through the wireless medium. A and C are placed such that their signal strengths are not strong enough for them to detect each others' transmissions, and yet are strong enough to interfere with each other at station B. The IEEE 802.11 frame contains a duration field in
feels as if it is now in hot water, while the one that was in the hot water feels as if it is now in cold water. The point is that the same thing-in this instance, room- temperature water-can be made to seem very different depending on the nature of the event that precedes it. Be assured that the nice little weapon of influence provided by the contrast principle does not go unexploited. The great advantage of this principle is not only that it works but also that it is virtually undetectable (Tormala 8(: Petty, 2007). Those who employ it can cash in on its influence without any appearance of having struc- tured the situation in their favor. Retail clothiers are a good example. Suppose a man enters a fashionable men's store and says that he wants to buy a three-piece suit and a sweater. If you were the salesperson, which would you show him first to make him likely to spend the most money? Clothing stores instruct their sales per- sonnel to sell the costly item first
(2004) observed high correlation sensitive to sanitation agents (Stopforth et al. Meat Decontamination 73 2003). Moreover, even though cells exposed 1995). However, excessive doses of the to acidic environments formed by diluted above antimicrobials may allow for antimi- organic acid run-off fluids may be injured by crobial resistance (EFSA 2008). Furthermore, sanitizing agents and be undetectable with in vitro studies suggest that exposure of common plating methods, they may recover pathogens to sublethal levels of certain meat and restore their acid resistance during sub- decontamination chemical agents may induce sequent exposure to fresh meat decontamina- tolerance to lethal levels of the same bio- tion run-off fluids (Skandamis et al. 2009). cides, as well as to other (heterologous)
annaabi.ee 
