Hybridization data interpretation

Hybrid systems. Depending on the problem to be solved, use can also be made of a combination of techniques leading to a hybrid system. For example, a rule-based system may use neural networks for solving classification subproblems (as is described in [Hopgood, 1993]), or a combination of a rule-based and a CBR system can be used as in the system for URS data interpretation described later in this paper. 

Figure 1 Schema of the hybrid rule-based/CBR system for interpretation of URS data.

Oxford Gene Technologies offers services and licenses their proprietary technologies. The array technique surveys hybridization across gene sequences. The customized DNA microarray service supports research activities, and includes consultation, experimental design, data analysis, and interpretation. 

Next we consider the compact star in the low mass X-ray binary 4U 1728-34. In a very recent paper Shaposhnikov et al. (2003) (hereafter STH) have analyzed a set of 26 Type-I X-ray bursts for this source. The data were collected by the Proportional Counter Array on board of the Rossi X-ray Timing Explorer (RXTE) satellite. For the interpretation of these observational data Shaposhnikov et al. 2003 used a model of the X-ray burst spectral formation developed by Titarchuk (1994) and Shaposhnikov Titarchuk (2002). Within this model, STH were able to extract very stringent constrain on the radius and the mass of the compact star in this bursting source. The radius and mass for 4U 1728-34, extracted by STH for different best-fits of the burst data, are depicted in Fig. 6 by the filled squares. Each of the four MR points is relative to a different value of the distance to the source (d = 4.0, 4.25, 4.50, 4.75 kpc, for the fit which produces the smallest values of the mass, up to the one which gives the largest mass). The error bars on each point represent the error contour for 90% confidence level. It has been pointed out (Bombaci 2003) that the semi-empirical MR relation for the compact star in 4U 1728-34 obtained by STH is not compatible with models pure hadronic stars, while it is consistent with strange stars or hybrid stars. 

C-21 methyl protons. The C-3 and C-16 melhine protons appeared at 8 3.82 and 4.99, respectively. The downfield chemical shift values of C-3 and C-6 methine protons were indicative of the presence of geminal oxygen functionahties. The C-6 resonated at 8 5.36 while the sp hybridized C-28 methylene protons resonated as two singlets, integrating for one proton each, at 8 5.56 and 6.06. A combination of H and C-NMR spectral data indicated to us that compound 11 has a steroidal skeleton. A detailed interpretation of broad C-NMR and DEPT spectra revealed the presence of three metlyl, ten methylene, eight methine and five quaternary carbon atoms in 11. The stereochemistry at various chiral centers was estabhshed with the aid of NOESY spectrum. 

There is a continuing debate as to whether inbred or outbred strains of rodents should be used. In theory, inbred strains are preferable because a more accurate knowledge of back-grormd tumour incidence is available. It may be, however, that a particular inbred strain may metabolise the test material in a certain way or have a genetic resistance to the development of a specific tumour type. Usually outbred strains of rat or hamster are used, but occasionally inbred mice strains are included. An FI hybrid mouse strain is frequently employed. In some circumstances outbred Syrian hamsters may be the species of choice. The most important factor is to have a sound knowledge of the background incidence of tumours in the species or strain selected. This information complements the concurrent control data and provides information on the susceptibility of the strain to rare tumour t)rpes. Modif)dng factors, such as diet, cage density, etc., must be kept as constant as possible to enable correct interpretation of the results. ... 

Carbon Chemical Shifts. In general, because carbon chemical shift values are dominated by the paramagnetic term, they are sensitive to a variety of factors such as hybridization, inductive, electric field, steric , resonance, and neighboring anisotropic effects. In many instances trends can be found for a series of compounds, but interpretation of the results is difficult. Therefore, it can be more enlightening to simply look for where changes in chemical shift do and do not occur and correlate them to better characterized data. 

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