BOLD effect

BOLD Effect, High Field. The close correspondence between neural activity in the brain and cerebral blood flow (CBF) forms the basis for... 

In the great majority of cases, no activation is detected inside the nidus during the performance of a task. This could be related to the absence of functional tissue within the nidus, but the detection of subtle and minor activation within an AVM could also be obscured by the complex relationships between the BOLD effect and AVM circulatory patterns (Vikingstad et al. 2000). Activation can be observed in the cortical regions adjacent to AVMs. In the majority of cases where brain AVMs are located in eloquent areas, a shift of the activated areas with a frequent interhemispheric transfer is observed. 

We commented above that the elastic and viscous effects are out of phase with each other by some angle 5 in a viscoelastic material. Since both vary periodically with the same frequency, stress and strain oscillate with t, as shown in Fig. 3.14a. The phase angle 5 measures the lag between the two waves. Another representation of this situation is shown in Fig. 3.14b, where stress and strain are represented by arrows of different lengths separated by an angle 5. Projections of either one onto the other can be expressed in terms of the sine and cosine of the phase angle. The bold arrows in Fig. 3.14b are the components of 7 parallel and perpendicular to a. Thus we can say that 7 cos 5 is the strain component in phase with the stress and 7 sin 6 is the component out of phase with the stress. We have previously observed that the elastic response is in phase with the stress and the viscous response is out of phase. Hence the ratio of... 

With strategic bond guidance, it is easy to find 2-Gp transform disconnections even if neither FG of an effective retron is present. In the case of the bridged aldehyde 160, recognition of the strategic bond shown (in bold face) keys FGI processes in both directions from the bond, which successfully establish the aldol retron leading to molecular disconnection by a sequence of aldol and Michael transforms, to generate a simple chiral precursor.31... 

Fig. 17a, b Substituent effects on the cyclic orbital interactions the (a) p-o -q and (b) p-o -q interactions are strengthened (shown by bold lines) by the electron-donating and -withdrawing substituents, respectively... 

Table 22 Summary of toxicological data for the critical toxic effects (studies used to derive TDIs in bold type). ...

Fig. 40.26. Effect of exponential smoothing (A. = 0.6) on a Gaussian peak (wi/, = 6 data points) (solid line original data bold line smoothed data).

To provide a mathematical description of a particle in space it is essential to specify not only its mass, but also its position (perhaps with respect to an arbitrary origin), as well as its velocity (and hence its momentum). Its mass is constant and thus independent of its position and velocity, at least in the absence of relativistic effects. It is also independent of the system of coordinates used to locate it in space. Its position and velocity, on the other hand, which have direction as well as magnitude, are vector quantities. Their descriptions depend on the choice of coordinate system. In this chapter Heaviside s notation will be followed, viz. a scalar quantity is represented by a symbol in plain italics, while a vector is printed in bold-face italic type. 

Fig. 2.7 Comparison of the Mulliken charges computed for 4-pyridone using the AMI semi-empirical model in (a) the gas-phase, and (b) water (bold) using the SM2 solvation model. The effect of including solvent is to increase the magnitude of the molecular dipole.

Figure 5. Energy level diagram for a spin 5/2 nucleus showing the effect of the first-order quadrupolar interaction on the Zeeman energy levels. The (m V2 m = -V2) transition (shown in bold) is independent of the quadrupolar interaction to...

Fig. 15.6. Effects on pH (top) and C02 fugacity (bottom) of reacting HC1 into a fluid not in contact with calcite (fine lines) and with the same fluid when it maintains equilibrium with calcite over the reaction path (bold lines).

Fig. 15.10. Calculated effects on pH of reacting sodium hydroxide into an initially acidic solution that is either closed to mass transfer (fine line) or in equilibrium with atmospheric C02 (bold line).

Fig. 23.3. Variation in C02 fugacity in a computer simulation of sampling, cooling, and then reheating a hypothetical geothermal fluid. Bold line shows path followed when system is held closed. Fine lines show effects of an open system in which fluid is allowed to degas C02 as it cools.

Fig. 2.4 The S-methylmethionine cycle and its interaction with the activated methyl cycle. The SMM cycle operates within the activated methyl cycle, and in effect short-circuits it. The reactions mediated by MMT and HMT are shown in bold. THF, tetrahydrofolate CH2-THF, 5,10-methylenetetrahydrofolate,...

Fig. 13 The steric assistance mechanism for the ortho-effect. Energy profile for the para-isomer is given in dotted lines whereas data for ort/zo-isomer are shown in solid lines. Calculations were performed at the BLYP/6-31G (in bold) and B3LYP/6-31G levels. P stands for products, R stands for reactants. Adapted from reference49.

Since diffusional effects are most important, we wish to emphasize these processes in the gas phase. For the control volume selected in Figure 9.7, the bold assumption is made that transport processes across the lateral faces in the x direction do not change - or change very slowly. Thus we only consider changes in the y direction. This approximation is known as the stagnant layer model since the direct effect of the main flow velocity (it) is not expressed. A differential control volume Ay x Ax x unity is selected. 

Snapshots illustrate specific example situations. Figure 6.18 shows snapshots depicting the state of our spreadsheet before and after an operation. (The thicker lines and bold type represent the state after the operation.) Notice that because we are dealing with a requirements model here, we show no messages (function calls) between the objects they will be decided in the design process. Here we re concerned only with the effects of the operation invoked by the user. This is part of how the layering of decisions works in Catalysis We start with the effects of operations and then work out how they are implemented in terms of collaborations between objects. 

Figure 8.4. Schematic illustration of the effect of adding an effector. Curve a (bold line) is the BI of the enzyme in the absence of an effector. We choose the arbitrary value 6 = 0.8, corresponding to the concentration C. We follow the variation in 0 along the vertical line at C. The addition of an activator R shifts the 61 upward (thin lines). The addition of an inhibitor shifts the Bis downward (dashed lines).

Marks Ml, Stitzel lA, et al (1985) Time course study of the effects of chronic nicotine infusion on drug response and brain receptors. 1 Pharmacol Exp Ther 235(3) 619-628 Marshall DL, Redfem PH, et al (1997) Presynaptic nicotinic modulation of dopamine release in the three ascending pathways studied by in vivo microdialysis comparison of naive and chronic nicotine-treated rats. 1 Neurochem 68(4) 1511-1519 Martinez D, Gil R, et al (2005) Alcohol dependence is associated with blunted dopamine transmission in the ventral striatum. Biol Psychiatry 58(10) 779-786 McClernon El, Kozink RV, Rose IE (2007) Individual differences in nicotine dependence, withdrawal symptoms, and sex predict transient fMRl-BOLD responses to smoking cues. Neuropsychopharmacology 33(9) 2148-2147... 

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