Applications of decision networks

In the last three decades, the ‘Principle of Optimality’ has been applied to a number of problems of multi-stage character. In this paper, we wish to review some of the work done by different authors using the principle.The current emphasis is on Decision Networks, which incorporates the basic principle and yet reveals the graphical structure of the problem similar to PERT/CPM charts. Actual applications of this technique are discussed in detail. It is expected that many new and real-life problems will be amenable to this technique.     

Isotope shifts in energy levels of the neutral neodymium atom

Isotope shift ΔT(142–144) have been evaluated for 281 odd and 110 even levels of the neutral neodymium atom from the isotope shift measurements made in the classified lines of Nd I spectra covering the region 3930–6510 Å. These investigations were carried out on a recording Fabry—Perot spectrometer using enriched isotopes excited in liquid-air cooled hollow cathodes. Electronic configurations of the energy levels have been discussed and probable configurations assigned to many odd and even levels. Most of the high even levels could be assigned to 4f³5d²6p configuration.     

Synthesis of 7,8-acetylenic analogs of hexahydro leukotriene-E4 with agonist and antagonist activities: convenient stereoselective routes to E- and Z-enynes

E- and Z-enynes available by stereoselective dehydrations of Co₂(CO)₆ completed and uncomplexed propargyl alcohols 13 and 5 produced acetylenic LT-E₄ analogs with contractile activity similar to leukotrienes. Their 5-desoxy analogs were found to have antagonist activity against LT-C₄ induced contractions on isolated guinea pig lung parenchyma.     

γ-Trimethylsilyl(triphenylsilyl) pyridines in syntheses of silicon-containing pyridinium ylids and indolizines

Three N-phenacyl--trimethylsilyl (triphenylsilyl)pyridinium bromides were converted to stable silyl-substituted pyridinium ylids. Six previously unknown silicon-containing indolizines were obtained by two methods, viz., 1,3-dipolar cycloaddition of dimethyl acetylenedicarboxylate (DMAD) to the pyridinium ylids and the Chichibabin reaction. Spectral data that confirm the structures of the synthesized compounds are presented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 965–968, July, 1980.     

Identity of coleonol with forskolin: structure revision of a base-catalysed rearrangement product

The identity of coleonol and forskolin is shown through structure revision of a rearrangement product isolated earlier from coleonol and is confirmed by direct comparison of authentic coleonol with forskolin $\text{1}$; in addition, coleonol-B should be correctly represented by structure $\text{4}$.     

Synthesis of butanoic acid 4,4′-[(4E, 6Z, 9Z-pentadecatrien-2-ynylidene)-bis with leukotriene- like activity: Novel acetylenic acetals and dithioacetals as antagonists of leukotriene-C4

A selective exchange reaction of the symmetrical acetal 5a with protected cysteine readily provided the hemi-thioacetals 9a and 11a related to leukotriene-E₄. Use of acetylene-bis-(diethyl acetal) 12 led to a facile synthesis of the title compound 17a. Its corresponding hexahydro analogs displayed marked antagonist activity against LT-C₄ induced contractions on isolated guinea pig lung parenchyma.     

Vibrational analysis of Fourier transform spectrum of the A3Π0-X1Σ+ and B3Π1-X1Σ+ transitions of indium monobromide

The emission spectrum of InBr molecule has been recorded in the region 350–400 nm on BOMEM DA8 Fourier transform spectrometer at an apodized resolution of 0.06 cm⁻¹ using microwave excitation technique. About 61 violet degraded and single headed bands have been recorded and are classified into two band systems, viz. A³Π₀-X¹Σ⁺ and B³Π₁-X¹Σ⁺. A few new bands have been observed and are fitted in the vibrational schemes of the two systems. Revised vibrational constants have been determined. The vibrational assignments have been confirmed by observing isotope effect due to InBr⁸¹ in the 30 bands of the A³Π₀-X¹Σ⁺ system and 19 bands of the B³Π₁-X¹Σ⁺ system. The analysis is further supported by calculating the Franck-Condon factor for InBr⁷⁹ and InBr⁸¹ molecules. The following vibrational constants (in cm⁻¹) have been determined from the analysis:      

The Fourier Transform Emission Spectrum of BΠ1-XΣ Band-System of InCl

The emission spectrum of the B³Π₁-X¹Σ⁺ band-system of the InCl molecule has been recorded on a Fourier transform spectrometer at an apodized resolution of 0.025 cm⁻¹. The rotational structure of 1-0, 2-1, 0-0, 0-1, 1-2, 0-2, and 1-3 bands belonging to the B³Π₁-X¹Σ⁺ transition of In³⁵Cl has been analyzed and accurate equilibrium rotational constants of the B³Π₁ state, have been obtained. Precise Λ-doubling constants of the B³Π₁ state (v=0, 1, and 2) are also reported for the first time.