Pathologic behavior

Drug addiction is a pathological behavioral syndrome that has to be strictly separated from physical dependence. An individual can be physically dependent on a drug without being addicted to it and vice versa. Transient neuroadaptive processes underlie physical dependence and tolerance to a drug, whereas persistent changes within specific neuronal systems underlie addictive behavior. 

A review article describing the occasionally pathological behavior of packed bed reactors is... 

Pathological Behavior. An important use of residence time measurements is to diagnose flow problems. As indicated previously, the first test is whether or not t... 

Isolation-induced aggression, mostly in mice Isolation housing prior to confrontation with another isolate or group-housed animal Territorial defense or pathologic behavior Full agonistic pattern the isolate attacks, threatens, pursues opponent... 

Dyssomnias consist of problems associated with the amount, quality or timing of sleep, whereas parasomnias involve pathological, behavioral, or psychological events that occur with sleep, specific sleep stages, or sleep-wake transitions (see also Chapter 11). The other two categories usually require treatment of the mental or physical condition that has created the sleep disturbance. For all categories, the short-term use of hypnotics may play a role. 

Wu Y, Wu Z, Butko P, Christen Y, Lambert MP, Klein WL, Link CD, Luo Y. 2006. Amyloid-beta-induced pathological behaviors are suppressed by Ginkgo biloba extract EGb 761 and ginkgolides in transgenic Caenorhabditis elegans. J Neurosci 26 13102-13113. 

Dan Luss I believe that there is still a need to study pathological behavior, especially in systems where it is caused by the interaction of the fluid flow and chemical reaction. For example, a major problem in the design and operation of a trickle-bed reactor is the presence of local hot spots, which have caused several major explosions. I ve just been involved in litigation that resulted from a reactor explosion it caused 15 million worth of damage at a plant in Corpus Christi. Most of the existing models in the literature are oversimplified and cannot predict this important feature. A model that will predict this behavior would be an important contribution. Another example is the self-ignition of coal piles, which is the major source of emission of sulfur dioxide into the atmosphere in South Africa. It s definitely desirable to get a better quantitative understanding of this behavior and how to prevent it. 

In carrying ont polynomial fits, one must be alert to possible pathological behavior. If the observed quantities 7 vary in a smooth but rapid and complex way with x one will need a high-degree polynomial to fit the data. This leads to a potentially serious problem. Two high-degree polynomials of different order that each fit a limited data set very well may yield different interpolated values and derivatives. Another problem situation arises when the measured physical quantity represents a singular function for example the heat capacity of a pure fluid at its critical density tends smoothly to infinity as Tapproaches the critical temperature y. In such a case, a polynomial fit will improperly round off the sharp physical feature. 

The highest experimental exposure levels that did not cause decreased hematocrit, kidney pathology, behavioral changes, or lethality (effects observed at higher exposures were above the definition for AEGL-2) have been used as the basis for determining AEGL-2 values. 

Threshold between normal and pathological behavior Figure 1 The quantitative trait model of neuroticism and anxiety. 

Aside from these large-scale, macroscopic deviations from ideal flow patterns, nonideal F t) responses can arise from diffusion within the reactor, from velocity profiles in tubular reactors that deviate from the plug-flow pattern, or from combinations of the two effects. It is the sum combination of all such processes that constitute what we have called mixing effects on chemical reactor performance In what follows, we will first attempt to develop a model adequate for the types of F t) and C t) behavior illustrated in Figures 4.3(b) and 4.4(b), then attempt to extend these ideas to modeling some of the more pathological behavior illustrated in Figure 5.1. 

Since this pathological behavior can only occur for very special ranges of the reaction rate parameters, (e.g., see Lee and Luss [90], we will not discuss it further here. Aris [91] has presented a comprehensive review vX these questions of uniqueness and stabili. ... 

Note that the Brusselator does not have a Takens-Bogdanov point. Theorems 10.2 and 10.3 are not applicable in this case, and the Brusselator displays somewhat pathological behavior as decreases toward unity. Equation (10.51) implies that a becomes arbitrarily large as Infinite a corresponds to an infinite Hopf... 

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