Direct encoding

An entirely different type of transport is formed by thermal convection and conduction. Flow induced by thermal convection can be examined by the phaseencoding techniques described above [8, 44, 45] or by time-of-flight methods [28, 45]. The latter provide less quantitative but more illustrative representations of thermal convection rolls. The origin of any heat transport, namely temperature gradients and spatial temperature distributions, can also be mapped with the aid of NMR techniques. Of course, there is no direct encoding method such as those for flow parameters. However, there are a number of other parameters, for example, relaxation times, which strongly depend on the temperature so that these parameters can be calibrated correspondingly. Examples are described in Refs. [8, 46, 47], for instance. 

The genetic information of living organisms is coded in DNA in the form of base pair sequences. There are four types of nucleotides, which are linked to a polynucleotide with a sugar-phosphate backbone. The arrangement of nucleotides along the one-dimensional chain is called the primary structure of DNA, which directly encodes the primary structure of proteins by means of... 

In the direct encoding, each molecular residue can be represented by its identity or its features. The most commonly used method for direct encoding involves the use of... 

Input/Output sequence encoding methods (see Table 9.1) PRF direct encoding of residue profile a = a-helix fi = P-sheet C = random coil t = (5-reverse turn L = loop %AA = amino acid composition FEAT = indirect encoding of sequence features MF = memory factor dist = distance Map = Kohonen map (with dimensions). 

Prochloron spp. synthesize patellamides using a bacteriocin-like process. " The final patellamide structures are directly encoded on a precursor peptide, PatE. This linear, ribosomally encoded peptide must be modified and cleaved to yield heterocyclized, macrocyclized patellamides. In particular, the patellamides must be cut out of the precursor peptide from both their C- and N-termini, a property not yet observed in any other cyclic... 

Fig. 6.14 Normal and abnormal phase contrast MRA of the circle of Willis, (a) Normal 2D phase contrast MRA with direction encoding in the rightdeft direction (vessel is bright if flowing right to left and dark if flowing left to right). There is normally...

Proteins play crucial and essential roles in all aspects of cellular function in all organisms. They are composed of linear strings of discrete subunits called amino acids. There are 20 naturally occurring amino acids, which can be grouped into different classes based on the chemical nature of their side chains acidic, basic, polar, aliphatic, aromatic. All the information necessary and sufficient to specify the final three-dimensional structure that is adopted by a protein is encoded by its amino acid sequence. The amino acid sequence of each protein is itself directly encoded in the chromosomal DNA, which is passed from generation to generation. 

In nature the 20 proteinogenetic standard (or natural) a-amino acids that are directly encoded by the genetic code are the building blocks of all proteins within humans and other eukaryotes. Amino acids that are not among these standard amino acids are named noncanonical amino acids, nonstandard or unnatural amino acids. 

The genes of an individual are collectively known as its genotype, while their physical expression, or result of decoding, is referred to as the phenotype. Some EAs exploit the mapping process from genotype to phenotype, while others rely on the fact that the phenotype is directly encoded, i.e., the genotype and the phenotype are the same. 

One potential advantage of the peptide nature of cationic peptides is their potential abiU ity to be synthesized recombinantly, since they can be directly encoded by DNA. There are certainly some limitations to this, since nonnatural amino acids (e.g., in the antibi otics) and many modiiicatjons (e.g., carboxyl-terminal amidation) are difficult to introduce recombinantly. As with the protein chemical procedures, however, one is not limited to "natural cationic peptides. 

Fourier velocity encoding was developed theoretically by [283] and verified experimentally by [284]. For details see [277]. Fourier velocity encoding takes phase contrast one step further by directly encoding the velocity into the velocity Fourier space or " -space" in the same way position is encoded into fc-space. 

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