Software Reviews

Super Vocab Machine Elements, Compounds, and Mixtures: A Matter of Mystery That's Life: Human Body Exploration     

An Approximate Distribution for the Maximum Order Complexity

In this paper we give an approximate probability distribution for the maximum order complexity of a random binary sequence. This enables the development of statistical tests based on maximum order complexity for the testing of a binary sequence generator. These tests are analogous to those based on linear complexity.     

Total synthesis of (±)-desepoxy-4,5-didehybromethylenomycin A

The total synthesis of (±)-desepoxy-4,5-didehydromethylenomycin A employing a retrolactonization strategy has been achieved.     

Synthesis of (±)-averufanin,1noraverufanin and bis-deoxyaverufanin

Alkylation of xanthopurpurin (8) by 2-hydroxy-6-methyltetrahydropyran (6a and 6b) produced bis-deoxyaverufanin (9). This reaction was first carried out in aqueous sodium bicarbonate solution. Use of (S)-(?)-proline in dimethylformamide gave a quantitative yield of 9. With this method, 1,3,6,8-tetrahydroxyanthraquinone (4) was alkylated by 2-hydroxytetrahydropyran (15). Chromatography of the reaction mixture produced noraverufanin (17) along with a dialkytation product 18. Synthesis of (±)-averufanin (12) with 42% yield was achieved.     

A COMPARISON OF DECAY KINETICS OF PHOTO-PRODUCED ABSORBANCE,EPR, AND LUMINESCENCE CHANGES IN CHROMATOPHORES OF RHODOSPIRRILLUM RUBRUM*

–Quantitative comparison of the decay rate for absorbance photochanges in chromatophores of R. rubrum at the major wavelengths of peaks and troughs (280, 365, 385, 433, 605, 763, 790, 810, 850, 865, 890 nm) reveal no major differences under a variety of sample conditions. In addition, the decay kinetics of EPR phtochange at the two environmental potentials used in this study are identical with the absorbance ph;otochange decay. Decay curves for fresh chromatophores, aged chromatophores, and fresh chromatophores at high ionic strength display a variety of half times and curve shapes. All of these data however, may be fit (within 10 per cent) by the equation x=αe^8.2t+βe^0.18t by merely varying the values of α and β. This is interpreted as meaning that any single trapping site may exist in one of two major forms each of which decays following a first order or pseudo-first order reaction. Although the change in decay pattern upon aging is not reversible, that due to high ionic strength is. The time dependencies for two light emission phenomena have been measured as well as their response to the oxidation state of molecules at the trapping site. A major component of long-lived luminescence follows pseudo-second order kinetics with a half time of 38 msec. A very long lived luminescence shows an increse with time which is nearly proportional to the decay of absorbance photochanges.     

Metal-ammonia reduction: the ring reduction of aromatic carboxylic esters

Aryl benzoates are reduced to 1,4-dihydroaromatics with Na/NH₃ in the presence of water.     

Disjoint Compatible Geometric Matchings

We prove that for every set of n pairwise disjoint line segments in the plane in general position, where n is even, there is another set of n segments such that the 2n segments form pairwise disjoint simple polygons in the plane. This settles in the affirmative the Disjoint Compatible Matching Conjecture by Aichholzer et al. (Comput. Geom. 42:617–626, 2009). The key tool in our proof is a novel subdivision of the free space around n disjoint line segments into at most n+1 convex cells such that the dual graph of the subdivision contains two edge-disjoint spanning trees.