Host selection physical factors

Recently, extensions of the core-shell definition of interpar-ticle electrical connectedness, whereby a connectivity range or shell of the order of the turmeling decay constant is defined, have been used in many analytical and simulation studies. " However, the characteristic tunneling length in various S3 tems is still difScult to predirt, as the dependence of this parameter on various factors such as the details of electrical transport in the system, and electronic and physical stmcture of the filler, as well as the properties of the host matrix are not well understood. Nevertheless, the tunneling distance is believed to be of the order of tens of angstroms and many studies select physically reasonable values within this range in their definitions of connectivity criteria. 

The selection or avoidance of potential host plants by phytophagous Insects Is guided by a complex combination of physical and chemical stimuli. Color, shape and olfactory cues may play a role In the Initial orientation, whereas acceptance or rejection of a plant depends on texture as well as chemical stimulants or deterrents. Initiation of feeding Is stimulated or deterred by the presence or absence of specific chemicals or groups of chemicals, many of which have been Identified. The selection of a suitable plant for ovlposltlon Is also crucial for survival of the progeny of most herbivorous Insects, but the chemical factors Involved are known In relatively few cases. Ovlposltlon stimulants and deterrents often appear to be quite different from the chemicals that elicit or Inhibit feeding responses of larvae. 

The behavior of Insects In selecting a host plant for food and shelter is affected by a wide array of physical and chemical stimuli. Chemicals that play a role in resistance mechanisms may interfere with an Insect s orientation, inhibit feeding, or deter ovipositlon. Most of the known mechanisms of resistance involve feeding deterrents, but the most vulnerable phase of the Insect life cycle may prove to be ovipositlon. Environmental factors may influence the ability... 

An additional factor that can contribute to the value of the EM is the stabilization provided by a template. Indeed if an assembly can serve as a host for a guest molecule, it will be selectively stabilized by host-guest interactions. This is the physical principle at the basis of the adaptive behavior of dynamic combinatorial libraries [66-68]. 

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