Structural plasticity

In parallel to the discovery of the long-term actions of dopamine on the sensitivity of the corticostriatal pathway, there have been a series of studies, which suggest that in the striatum, as in the hippocampus, the changes in synaptic strength have structural consequences. The earliest of these is probably the study of spine numbers in the neostriatum after destruction of dopamine input (Ingham et al., 1989). After a 6-OHDA lesion it seemed that there were fewer spines on individual dendrites in the striatum. The effect was visible as soon as the damage became stable at three weeks after the lesion and was still present one year later. But the lesion does not involve glutamatergic neurones. So perhaps the spines that are lost may have had dopamine synapses on them. That too seems unlikely since we estimated earlier that only about 11 % of spines would have a dopamine 

---

Packed-Bed Fixed-Film Systems These systems were originaUy termed anaerobic trickhng filters because the first systems were submerged columns filled with stones run under anaerobic conditions (Fig. 25-57). A wide variety of packed media is now used ranging in size from graniiles 40 mesh to 7.5-cm (3—in) stones. Many systems use open structure plastic packing similar to that used in aerobic trickhng filters. 

Heger, F. J., Structural Plastics Design Manual, ASCE, 1981. 

Robinson, T.E., Kolb, B. Structural plasticity associated with exposure to drugs of abuse. Neuropharmacology. 47 33, 2004. 

Different structural materials have different thermal contraction coefficients, meaning that accommodations should be made for their different dimensions at cryogenic temperatures. If not, problems associated with safety (e.g., leaks) may arise. Generally, the contraction of most metals from room temperature (300 K) to a temperature close to the liquefaction temperature of hydrogen (20 K) is <1%, whereas the contraction for most common structural plastics is from 1% to 2.5% [23]. 

The response of neural tissue to damage involves some degree of structural plasticity, as in development 855 Activation and adaptation behaviors maybe mediated by hormones 856... 

Although the exact molecular basis underlying longterm plasticity is not clear, the general consensus has been that structural plasticity is a fundamental property of... 

Stronge and Yu, Dynamic Models for Structural Plasticity, W. J. Stronge and T, X. Yu, Springer-Vcrlag London, Ltd, London, England, 1993... 

Use of structural plastics long fibre reinforced thermoplastics (LFRT), glass mat thermoplastics (GMT), thermoplastic sandwich structures, carbon fibre reinforced thermoplastics. 

Oligosilsesquioxanes with long-chain alkyl substituents have been offered as water-repellents and adhesives for pearlite heat-insulating plates and materials and as damping fluids and structural plasticizers for polymeric ceramic materials which allow to control the properties of the latter in the manufacture of the items concerned. 

While polymer melts and non-cross-linked elastomers flow readily when stress is applied, structural plastics must resist irreversible deformation and behave as elastic solids when relatively small stresses are applied. These plastics are called ideal or Bingham plastics with their behavior described mathematically by... 

Another reason to consider a novel role for the cholinergic basal forebrain is that cholinergic axons exhibit exquisite structural plasticity, similar to that of monoaminergic axons, and in marked contrast to that of glutamatergic axons (Farris et ah, 1993 Woolf, 1996). Wholly new cholinergic axon branches bear-... 

Cellular Mechanisms of Stress-Induced Structural Plasticity. 313... 

Figure 11.4 The all-composite Aberfeldy footbridge over the river Tay in Scotland. Photograph published courtesy of Maunsell Structural Plastics Ltd...

It is evident from the above discussion that lignin is still a material of the future in the areas of structural plastics and as a source of chemicals. However, the ever-increasing demand for a clean environment hastens the day when lignin is used on a large industrial scale. This day is much nearer than was predicted only a few years ago. From this point of view, it is evident that research should continue and more funds should be allocated to research work on lignin modification. 

NMR Studies of Biomolecular Dynamics and Structural Plasticity Using Residual Dipolar Couplings... 

---