Generalized evaluation subgroups of product spaces relative to a factor

For any -complexes and , we show that . We use this fact to compute generalized evaluation subgroups of generalized tori relative to a sphere.

     

A characterization of discrete unimodality with applications to variance upper bounds

Bertin and Theodorescu (1984,Statist. Probab. Lett.,2, 23–30) developed a characterization of discrete unimodality based on convexity properties of a discretization of distribution functions. We offer a new characterization of discrete unimodality based on convexity properties of a piecewise linear extension of distribution functions. This reliance on functional convexity, as in Khintchine's classic definition, leads to variance dilations and upper bounds on variance for a large class of discrete unimodal distributions. These bounds are compared to existing inequalities due to Muilwijk (1966,Sankhy, Ser. B,28, p. 183), Moors and Muilwijk (1971,Sankhy, Ser. B,33, 385–388), and Rayner (1975,Sankhy, Ser. B,37, 135–138), and are found to be generally tighter, thus illustrating the power of unimodality assumptions.     

Enhanced emission and its switching in fluorescent organic nanoparticles

A new class of organic nanoparticles (CN-MBE nanoparticles) with a mean diameter of ca. 30-40 nm, which exhibit a strongly enhanced fluorescence emission, were prepared by a simple reprecipitation method. CN-MBE (1-cyano-trans-1,2-bis-(4'-methylbiphenyl)ethylene) is very weakly fluorescent in solution, but the intensity is increased by almost 700 times in the nanoparticles. Enhanced emission in CN-MBE nanoparticles is attributed to the synergetic effect of intramolecular planarization and J-type aggregate formation (restricted excimer formation) in nanopaticles. On/off fluorescence switching for organic vapor was demonstrated with CN-MBE nanoparticles.     

Probing the Binding Region of the Single-Stranded DNA-Binding Domain of Rat DNA Polymerase β Using Nanosecond-Pulse Laser-Induced Cross-Linking and Mass Spectrometry

In recent years, there has been a significant number of studies in which UV light has been used as a reagent to induce cross-links in nucleic acid-protein complexes. An area of considerable interest among those interested in structural biology is the garnering of information about the sites of cross-linking within the protein and nucleic acid members of photolinked conjugates, under the assumption that such knowledge should lead to identification of contact regions or sites within the native complexes. In this paper, we present our results from a photocross-linking study of the complex of the single-stranded DNA-binding domain of rat DNA polymerase β (pol β-ss) with the oligonucleotide d(ATATATA). In this study, we have used single nanosecond laser pulses as the cross-linking reagent and matrix-assisted laser desorp-tion/ionization-time of flight mass spectrometry as an analytical tool to identify cross-linked peptides purified from proteolytic digests of the cross-linked complex. Six cross-linked peptides have been identified in tryptic digests of the protein-oligonucleotide conjugates that result from irradiation of the pol β-ss-d(ATATATA) complex with a single laser pulse. Comparisons with NMR data in the literature for the same complex show that each of the cross-linked peptides contains amino acids that are in contact with the nucleic acid component of the complex.