From Allostatic Load to Allostatic State—An Endogenous Sympathetic Strategy to Deal With Chronic Anxiety and Stress?

The concepts of allostatic load and overload, i. e., a dramatic increase in the allostatic load that predisposes to disease, have been extensively described in the literature. Here, we show that rats engaging in active offensive response (AOR) behavioral strategies to chronic predator scent stress (PSS) display less anxiety behavior and lower plasma cortisol levels vs. rats engaging in passive defensive response (PDR) behavioral strategies to chronic PSS. In the same chronic PSS paradigm, AOR rats also have higher lactate and lower glutamate levels in amygdala but not in control-region hippocampus vs. PDR rats. The implications of these findings for regulation of allostatic and stress responses, and post-traumatic stress disorder (PTSD) are discussed

Discrete 2D model of combustion in a binary mixture containing mechanically activated and non-activated layers

A discrete 2D model of combustion process in donor–acceptor mixture consisting of activated and non-activated reaction cells was proposed. The influence of the activated composition fraction and cell size on the burning velocity of a combined mixture was analyzed. Calculations showed that an increase in the activated composition fraction elevates the average burning velocity. It was found that burning velocity vs cell size dependence passes through a maximum

Specific features of the synthesis of ceramic-metal materials in an unsteady combustion regime

A mathematical model has been constructed and investigated by numerical methods for unsteady gasless combustion of a binary mixture under the conditions of thermocapillary flow of the melt of one of the components. Various unsteady regimes have been identified for the propagation of a synthesis wave depending on mass concentrations of components and the initial porosity of the mixture. An investigation has been made into the process of forming the macrostructure of synthesis products in a self-sustained oscillating regime of combustion. A possibility in principle has been shown for combustion of mixtures with excess of a low-melting component at a higher rate than in combustion of a mixture of a stoichiometric composition

Mathematical simulation of volume and gasless wave combustion in a hybrid mixture of activated and inactivated powders

Mathematical models constructed in the macroscopic approximation are used to perform a theoretical study of volume and wave synthesis in a hybrid mixture consisting of nonactivated and activated powders of the same composition. Synthesis dynamics depending on the fraction of activated powder at different values of the preliminary mechanical activation parameters is considered. Analytical formulas are obtained for approximate estimates of the temperature and time of synthesis in nonactivated and activated composition

Gasless combustion in combined binary mixtures containing low-melting reagent: mathematical model

Gasless combustion in the combined binary mixtures formed by alternating non-activated and mechanically activated layers containing low-melting reagent was mathematically modelled in a macroscopic approximation, with account for a phase transformation (melting) in a low-melting reagent. The phase transition was found to either decelerate or accelerate combustion: the former happens when some amount of the reaction heat is spent on the recovery of a low-melting compound, while the latter takes place when melting occurs at lower temperatures and is accompanied by an increase in the interphase (contact) surfac