Event-generating mechanisms

The complete system responses are determined by the interactions, i.e. resonances, between the subthreshold and event-generating mechanisms. Again, in the HPA axis model, these interactions, so far, are rather simple and unidirectional. The circadian pacemaker modulates the H PA feedback loops in a nonlinear multiplicative way but is itself not influenced by the dynamics of the cortisol releasing processes. In contrast, in the neuronal and psychiatric models, the two subsystems are interlinked by a common control variable, the membrane voltage and the disease variable, respectively. These interlinks are a major source of very complex, inclusively chaotic dynamics [96, 111, 112]. 

In order to learn about the true quantum efficiency of photogeneration one therefore has to study the photoinduced charge generation mechanism at faster time scales. Pump probe spectroscopy utilising a few optical-cycle laser pulses (5-6 fs) in the visible spectral range with broadband frequency conversion techniques [89] now makes it possible to study extremely fast optically-initiated events with unprecedented time resolution. Such a setup was used to time-resolve the kinetics of the charge transfer process from a polymer chain to a fullerene moiety in thin films of poly[2-methoxy, 5-(3, 7 -dimethyl-octyloxy)]-p-phenylene vinylene (MDMO-PPV) and [6,6]-phenyl C6i butyric acid methyl ester (PCBM). Solutions prepared from 1 wt% solutions of toluene on thin quartz substrates were studied. 

In order to influence ceU growth and function, mechanical forces may trigger the same signaling pathways that are activated by conventional chemical stimuli (e.g., growth factors and hormones). A vast amount of data has shown that many of the biochemical events generated by ceUs in response to forces are similar to those that occur foUowing recognition of chemical stimuli (see References 3,33,45, and 52-56... 

One Private Buffer per Monitor. An alternative implementation would be to provide a private buffer for each monitor. As a consequence, there is no need for an event dispatcher anymore. Although diminishing the number of potential concurrent accesses to the same buffer, a synchronisation mechanism is still necessary when events generated by multiple threads are needed by the same monitor. Furthermore, additional issues must now be considered ... 

However, reaction 7 suffers other shortcomings, eg, entropy problems. Other proposals range from trace peroxidic contaminants to ionic mechanisms for generating peroxides (1) to cosmic rays (17). In any event, the initiating reactions are significant only during the induction period (18). 

Work in the mid-1970s demonstrated that the vitamin K-dependent step in prothrombin synthesis was the conversion of glutamyl residues to y-carboxyglutamyl residues. Subsequent studies more cleady defined the role of vitamin K in this conversion and have led to the current theory that the vitamin K-dependent carboxylation reaction is essentially a two-step process which first involves generation of a carbanion at the y-position of the glutamyl (Gla) residue. This event is coupled with the epoxidation of the reduced form of vitamin K and in a subsequent step, the carbanion is carboxylated (77—80). Studies have provided thermochemical confirmation for the mechanism of vitamin K and have shown the oxidation of vitamin KH2 (15) can produce a base of sufficient strength to deprotonate the y-position of the glutamate (81—83). 

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