This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract This study analyses the effects of nongray gas radiation on double diffusive convection, in a square differentially heated cavity filled with air-CO2 mixtures, when the buoyancy forces thermal and mass are cooperating or opposing. The radiative source term in the energy equation is evaluated by the discrete ordinate method solving the radiative transfer equation and the SLW spectral model accounting for real radiative properties of absorbing species.
Attachment RD3 Dependence on approval Comparative study of the concentration dependence others RD4 A study comparing the TCI to the five factor model of personality found that reward dependence was substantially positively associated with extraversion and to a lesser extent openness to experience.
Striatal projections and Tracts between the prefrontal cortex predict our individual differences in reward processing, reward dependence and reward-guided behaviors. High reward dependence is characterized by learning from reward signals, persisting repetition of actions that are associated with rewards, increased sociability and a need for social approval.
The striatum, especially the dorsal regionsis necessary to carry out these functions. These findings demonstrate that people with high reward dependence who feel a greater need for social rewards and verbal approval have more opiate receptors found in the ventral striatum, whereas people with low reward dependence have a lower concentration of receptors.
MRI fMRI studies have shown that individuals with immature development of the inferior part of the frontal lobe around the midline inner surface of the brain, showed greater reward dependence.
The researchers warn that these studies are only correlational and cross-sectional and none of this research is definitive in proving that brain structure determines personality but it could be that personality, through experience, may help in determining the structure of the brain.
Social Reward Dependence has also been associated with the temporal lobesthe caudate Grey Matter Density GMD in the orbitofrontal cortex and the basal ganglia of the ventral striatum.
These significant findings show a correlation between primary reward processing circuits and reward dependence, keeping with the fMRI research studies that demonstrated that, following the experience of complex rewards the activation of the striatal circuits occur. Primary reward processing has also been associated with the orbitofrontal cortex and the grey matter density in the ventral striatum, whereas higher RD scores were associated with the interactions between dopamine projections, neuropeptides and opiates in the ventral striatum.
It is demonstrated here, then, that there is evidence for a structural disposition of the brain towards social interactions, and that both sensitivity to salient social reward cues and primary reward processing share the same brain systems. The medial prefrontal cortex and orbitofrontal cortex, along with other temporal structures, project to the temporal pole, enabling reward stimuli information between the two regions to be integrated.
In an fMRI study, the temporal poles and the ventral striatal areas have been shown to be activated in response to social rewards such as humor and also in looking forward to simpler rewards such as money.
When produced in normal levels, norepinephrine creates a sense of well-being, but low levels of norepinephrine cause symptoms of depressionlack of arousal and lack of motivation.
In humans, this leads to then a negative feedback mechanism whereby we seek out pleasurable activities to remove the negative affect caused by the low levels of norepinephrine, therefore increasing our reward dependence.
Our neuro-circuity is as such that when we stop having access to such pleasurable objects of desire, we then experience negative consequences withdrawal symptoms. Addictive behaviors then arise to alleviate such negative consequences and the cycle continues.
It is then suggested that individuals with such predispositions should adopt preventive strategies or avoid such situations, where they seek such rewards that could potentially have adverse consequences.
The Brain on Substance Dependence According to researchers the reward circuit is continuously involved in initiating behaviors that are essential for the sustenance of the individual such as eating or of the preservation of the species such as sexual reproduction.
Food intake or sexual stimuli then lead to endorphine regulated release of dopamine in core substrates of the reward processing system, which subsequently activate craving sensations.
The development of addictions is then directly related to the acquired or genetic abuse of the reward circuit.
This finding then suggests that individuals with increased reward dependence have a relative deficit of endorphines and are possibly at higher risk for developing addictive behaviors. Proposed Type 1 Alcoholism is clinically characterized by a late onset after the age of 25 of alcohol-related problems usually after an extended period of drinking that is socially encouragedstrong psychological dependence loss of control with guilt and fear about alcohol dependence, and rare occurrence of fighting and arrests after drinking.
Psychologically, it is proposed to be characterized by high reward-dependence in both males and females. Type 2 Alcoholism is clinically characterized by an early onset of alcohol-related problems before the age of 25 independent of external circumstancesdrinking often associated with antisocial behaviorspontaneous alcohol-seeking behavior inability to abstainlow associated guilt and fear, and frequent fighting and arrests after drinking.
Since the inception of these theories they have been tested in several investigations and the results have been consistent with the theories. Whereas they scored high on the Persistence sub scale of RD, representing resistance to extinction of previously rewarded behavior thereby reengaging in the addictive behavior.
Craving has increasingly received attention as a critical phenomenon in addictive psychopathology.The protocols used in this study were fairly simple; the accuracy of the method can be further improved by including measurements for additional biophysical parameters (e.g.
frequency-dependence, pH-dependence, etc). Full-Text Paper (PDF): Comparative Study of Carrier Lifetime Dependence on Dopant Concentration in Silicon and Germanium. To evaluate association of the dose-dependent effect of rifampicin, an OATP1B inhibitor, on the plasma concentration–time profiles among OATP1B substrates drugs and endogenous substrates.
Methods Eight healthy volunteers received atorvastatin (1 mg), pitavastatin ( mg), rosuvastatin ( mg), and fluvastatin (2 mg) alone or with rifampicin ( or mg) in a crossover fashion.
The concentration dependence of PCARS intensity has been measured for the cm−1 band of benzene in five different solvents and compared with that of Rayleigh scattering intensity. The temperature dependence of PCARS and Rayleigh scattering has also been studied for neat benzene.
The concentration dependence of PCARS and Rayleigh scattering shows a similar correlation to the . Measurement of transference numbers for lithium ion electrolytes via four different methods, a comparative study. The ionic radii showed no strong concentration dependence, leading to the conclusion that the mobility of the lithium species, that is affected by the size of the moving species did not change much with concentration contrary to.
Recently, some attempts have been made to study double diffusive convection coupled to radiation in participating gases, accounting for the real (nongray) radiative properties of the mixture (absorption varies with temperature, concentration, and wavelength).