Tail segments

Figure 11. A schematic representation of the mean-field approximation, a central issue in the self-consistent-field theory. The arrows symbolically represent the lipid molecules. The head of the arrow is the hydrophilic part and the line is the hydrophobic tail. On the left a two-dimensional representation of a disordered bilayer is given. One of the lipids has been selected, as shown by the box around it. The same molecule is depicted on the right. The bilayer is depicted schematically by two horizontal lines. The centre of the bilayer is at z = 0. These lines are to guide the eye the membrane thickness is not preassumed, but is the result of the calculations. Both the potential energy felt by the head groups and that of the tail segments are indicated. We note that in the detailed models the self-consistent potential profiles are of course much more detailed than shown in this graph...

Figure 19. The root-mean-square (RMS) position of each segment of both acyl chains of SOPC lipids is plotted as a function of the average position of the segment. The sn tail is given by the closed symbols, and the sn2 tail is given by the open symbols. Various numbers of the tail segments and of the backbone segments are indicated. The lines are drawn to guide the eye. The arrow points to the position of the unsaturated bond, (a) SCF results (conversion from dimensionless units to real units is approximately a factor of 0.2 nm), (b) MD results (the average over the sides of the bilayer is taken)...

The distribution of loop segments is a simple exponential function of the distance from the surface while that of tail segments is the difference of two exponential functions and has a maximum at an intermediate distance. 

Scheutjens and Fleer further calculated50 the concentration distributions of loop and tail segments, the root-mean-square thickness of the adsorbed layer, and the average numbers and lengths of trains, loops, and tails. They also computed the distributions of trains, loops, and tails from the free segment probability Pj, which may be represented by... 

The spectral line shape is concentration dependent, but remains motionally narrowed until relatively high polymer concentrations are reached (Figure 1-B,C and reference 27). Loop and tail segment density near the surface may be large, but falls off rapidly with distance above the surface. We therefore expected tails and all but the smallest loops (and surface extended loops) would exhibit three line spectra similar to that observed with the free, isolated polymer molecule. 

The volume fraction falls off sharply over 0 < z < %Rg and is dominated by the exponential decay of segments contained in loops. In the interval 0.80Rg < z < 1.80Rg, q> decays more slowly with tail segments making up... 

Reptation steps (a) formation of a loop at the tail of the snake and elimination of the tail segment of the confining tube ... 

As the only seriously toxic US species, it may be distinguished from other less toxic species by its very slender tail segments and long slender pincers. Reaching only 1.5" at maturity, it is a comparatively small scorpion. The body is a yellow-ish/golden-brown or straw colored and the color becomes darker with age. 

The effect of coal caving at the supports of tail segment must be ensured (Wang 2004). 

Before we discuss the definitions of micellar properties, we first comment on how an aggregate is defined. Any surfactant chain with at least one tail segment that has a nearest-neighbor contact with a tail segment from another surfactant chain is considered to be part of an aggregate, which we will call a micelle. Nonaggregated surfactant chains are called free surfactants. Any solute chain that has at least one nearest-neighbor contact with a tail bead in a micelle is considered to be a solubilized or encapsulated solute. All other solute chains are considered to be unsolubilized solutes. 

Step 3, Split both parents at this point, thus producing two head segments and two tail segments. 

Step 4. The tail segments are then swapped over to produce two new fiill-length chromosomes. 

Adsorption of a polymer necessarily implies a change in the conformation the most common description is the loop-train-tail model (Jenkel and Rum-bach 1951) shown schematically in figure 5.10. The trains are made up of segments in direct contact with the surface, whereas loops have no direct contact with the surface but are in close proximity. Tails are non-adsorbed chain ends. Although tail segments may constitute a small proportion of all segments, they determine the hydrodynamic layer thickness of the adsorbed polymer. Many other properties of adsorbed polymers are determined by the total segment concentration profile as a function of the distance from the surface. 

Figure 4 Volume fraction profiles for tail segments using the Monte Carlo simulation method. 0 = 0.8. The other parameters are given in Table 3. A1B18A1[B] and A1B19[ ] and B20 [4 ].

Fig. 7 The number of amphiphiles in primary bilayer vs. number of tail segments in amphiphile. ( ) first appearance of stable bilayer ( ) packing limit of bilayer...

Abstract Configurational-bias Monte Carlo simulations in the Gibbs ensemble have been carried out to determine the vapor-liquid coexistence curve for a pentadecanoic acid Langmuir monolayer. Two different force fields were studied (i) the original monolayer model of Karaborni and Toxvaerd including anisotropic interactions between alkyl tails, and (ii) a modified version of this model which uses an isotropic united-atom description for the methylene and methyl groups and includes dispersive interactions between the tail segments and the water surface. 

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