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Parasitic wasps propagate by injecting their eggs into a caterpillar that then becomes paralyzed as the eggs inside develop into wasp larvae. The wasp larvae kill the caterpillar host as they feed on it, form cocoons, and finally develop into wasps. In attempting to discover how such wasps detect the presence of the caterpillar hosts that are so critical to the wasps' propagation, researchers have uncovered an intriguing defense mechanism developed by the plants on which the caterpillars feed.

When chewed on, many plants release volatile compounds from both damaged and undamaged tissues. When these compounds are toxic to the insects that feed on the plants, they can help defend the plants from such attacks. However, the plants on which the wasps' caterpillar hosts feed have evolved an even more complex defense: the caterpillar-infested plants appear to release volatile chemicals that attract parasitic wasps, which then prey on the caterpillars. Scientists originally suspected that the wasps were attracted by an odor, reminiscent of cut grass, that is released as the caterpillar feeds, but a recent study suggests that a different set of volatile attractants is involved. In this study, when researchers used a razor blade to mimic caterpillar damage on the leaves, only grassy odors were emitted, not the volatile compounds that attracted wasps. However, when oral secretions from the caterpillars were applied to these damaged leaves, the leaves released the wasp attractants several hours later. Further tests revealed that oral secretions placed on the razor-damaged leaves stimulated the release of such attractants, making the plants as attractive to wasps as plants that had suffered actual caterpillar damage. These results suggest that chemicals from the caterpillar must be present for these attractants to be released and that unlike the grassy scent, which emanates only as the caterpillar on the plant, the wasp attractants are produced several hours after the attack and persist for several hours, perhaps days. Researchers have launched additional studies to determine whether the wasps' capacity to prey on caterpillars can be enhanced to the extent that the wasps could be used as a natural pesticide to "police" plants and protect them from crop-destroying caterpillars.

Although a substantial body of evidence Indicates that flexible and participative work arrangements make possible significant performance advantages over more traditional centralized and hierarchical structures, the proportion of businesses that have so transformed themselves remains quite small. Why, then, do firms that purport to be rationally acting organizations appear to resist the very methods that would best equip them to achieve their stated goals?

One line of analysis points toward the phenomenon of structural inertia, suggesting that organizations are "imprinted" with the conditions under which they were born, tending thereafter to ding to long-established routines, production methods, and identities. A second approach fastens on resistance to change among middle managers, who are said to view new work practices as threats to their traditional status and authority. A third approach suggests that because firms have tended to adopt innovations singly, rather than in clusters, the firms often fail to achieve far-reaching organization change.

Although each of these perspectives contains a partial truth, each one is limited. Analysis using the concept of structural inertia tends to emphasize the conservative aspects of organizational culture and to neglect inside factors as sources of change. While theories of managerial resistance have stressed the importance of within-firm political processes, they often endow upper levels of management with an omniscience and openness to egalitarian practices that upper-level managers do not possess. Finally, the last approach often views new practices as if they exist in a vacuum—as if they are unmediated by the manner in which they are introduced.

Consider a mirage on a hot toad: when light tays hit the hot ait just above the surface, they bend. Although light moves through a vacuum at a certain constant speed, it moves more slowly through any transparent medium, such as water or gas. Light travels faster in the thin air near the road than it does in the colder, denser air above, and the difference in speed makes it shift direction as it crosses the boundary between the two. Rays once headed downwards from the sky are redirected to your eye, hiding part of the road with a shimmering image.

A research team has constructed an apparatus to cloak an object from electromagnetic radiation (EMR)—in this case, microwaves—making the object "invisible" to microwave-based detection devices, somewhat as a mirage on a hot road makes the road invisible. The apparatus bends incoming microwaves around the object, using a class of recently created metamaterials—materials that gain certain desired properties directly from their engineered structures rather than from their composition. These metamaterials possess the ability, not found in nature, to bend microwaves at extreme angles. The metamateria! in this case—thin, rigid sheets of fiberglass insulator stamped with conducting loops, coils, and tiny rectangles—was designed to control the movement of incoming EMR.