Failures of coordination

Fig. 6. Failure of coordinate driving method due to a long valley not leading to the transition structure. The dotted curve is the steepest-descent path from the saddle point.

NASA is certainly not free from concerns of coordination neglect and communication breakdown. NASA s size, geographical distribution, and cultural variation make effective communication and coordination difficult (McCurdy, 1994). One particularly glaring example of an accident caused in part by a failure of coordination is the September 23, 1999 loss of NASA s Mars Climate Orbiter spacecraft. NASA s investigation of the accident revealed that it came about at least in part because NASA engineers used metric units in their calculations while Lockheed Martin engineers used English units (www.cnn.eom/TECH/space/9909/30/mars.metric.02/). 

All three cases of aberrant behavior of young somatic hybrids which we have just described may be regarded as failures of coordination of various degrees. Although their precise causes are obscure at this time, we wish to indicate some of the most obvious among the many possible explanations. 

In concluding, we would like to emphasize that we have described the failures of coordination and discussed in some detail their possible mechanisms because we believe that it is partly through functional mistakes of this sort that it will be possible to recognize both the kinds of signals which are involved in the regulation of cell cycles and the time at which these signals are given. 

Thus, the Tsai-Wu tensor failure criterion is obviously of more general character than the Tsai-Hill or Hoffman failure criteria. Specific advantages of the Tsai-Wu failure criterion include (1) invariance under rotation or redefinition of coordinates (2) transformation via known tensor-transformation laws (so data interpretation is eased) and (3) symmetry properties similar to those of the stiffnesses and compliances. Accordingly, the mathematical operations with this tensor failure criterion are well-known and relatively straightforward. 

If no laminae have failed, the load must be determined at which the first lamina fails (so-called first-ply failure), that is, violates the lamina failure criterion. In the process of this determination, the laminae stresses must be found as a function of the unknown magnitude of loads first in the laminate coordinates and then in the principal material directions. The proportions of load (i.e., the ratios of to Ny, to My,/ etc.) are, of course, specified at the beginning of the analysik The loaa parameter is increased until some individual lamina fails. The properties, of the failed lamina are then degraded in one of two ways (1) totally to zero if the fibers in the lamina fail or (2) to fiber-direction properties if the failure is by cracking parallel to the fibers (matrix failure). Actually, because of the matrix manipulations involved in the analysis, the failed lamina properties must not be zero, but rather effectively zero values in order to avoid a singular matrix that could not be inverted in the structural analysis problem. The laminate strains are calculated from the known load and the stiffnesses prior to failure of a lamina. The laminate deformations just after failure of a lamina are discussed later. 

When the states and 1 are of equal energy, AG = 0 and Eq. (5-78) becomes Eq. (5-76) with this condition, also, jc = a and y = z, describing the pure concerted reaction along the x coordinate with no net perpendicular displacement. An apparent failure of Eq. (5-76) may mean that Eq. (5-78) is applicable. 

Iron(II) alkyl anions fFe(Por)R (R = Me, t-Bu) do not insert CO directly, but do upon one-electron oxidation to Fe(Por)R to give the acyl species Fe(Por)C(0)R, which can in turn be reduced to the iron(II) acyl Fe(Por)C(0)R]. This process competes with homolysis of Fe(Por)R, and the resulting iron(II) porphyrin is stabilized by formation of the carbonyl complex Fe(Por)(CO). Benzyl and phenyl iron(III) complexes do not insert CO, with the former undergoing decomposition and the latter forming a six-coordinate adduct, [Fe(Por)(Ph)(CO) upon reduction to iron(ll). The failure of Fe(Por)Ph to insert CO was attributed to the stronger Fe—C bond in the aryl complexes. The electrochemistry of the iron(lll) acyl complexes Fe(Por)C(0)R was investigated as part of this study, and showed two reversible reductions (to Fe(ll) and Fe(l) acyl complexes, formally) and one irreversible oxidation process."" ... 

Pd(OAc)2 works well with strained double bonds as well as with styrene and its ring-substituted derivatives. Basic substituents cannot be tolerated, however, as the failures with 4-(dimethylamino)styrene, 4-vinylpyridine and 1 -vinylimidazole show. In contrast to Rh2(OAc)4, Pd(OAe)2 causes preferential cyclopropanation of the terminal or less hindered double bond in intermolecular competition experiments. These facts are in agreement with a mechanism in which olefin coordination to the metal is a determining factor but the reluctance or complete failure of Pd(II)-diene complexes to react with diazoesters sheds some doubt on the hypothesis of Pd-olefin-carbene complexes (see Sect. 11). 

Chapter 13). Failure of central control of muscle action can also have severe consequences. Malfunctioning of some parts of the central control mechanism can result in failure of muscles to contract normally and in a coordinated manner, e.g. Parkinson s disease (Chapter 14) or result in excessive fatigue (chronic fatigue syndrome (Chapter 13)). 

One reason for the failure of the radius ratio rules is that ions do not behave like hard spheres. Even those that are hard in the Pearson (1973) sense can still be compressed. This is clearly seen in the way the bond length varies with the bond valence. If cation anion bonds can be compressed, so can the distance between the 0 ions in the first coordination sphere. The stronger the cation anion bonds, therefore, the closer the anions in the first coordination sphere can be pulled together (Shannon el al. 1975). 

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