Bacterial conjugation in the human gut microbiota is believed to play a major role in the dissemination of antibiotic resistance genes and virulence plasmids. However, the modulation of bacterial conjugation by the human host remains poorly understood and there is a need for controlled systems to study this process. We established an in vitro co-culture system to study the interaction between h...

The polycation polylysine, at different degrees of polymerization, was found to cause a marked inhibition of the conjugation process. Inhibition of conjugation by polylysine was highly dependent on the molecular weight of the polymer. When polylysine of a mol wt of 1,250 (degree of polymerization=6) was used, a concentration of 1.6 X 10(-5) M was required for a complete inhibition of conjugatio...

Conjugation is a process in which bacteria exchange DNA through a physical connection (conjugative junction) between mating cells. Despite its significance for processes such as the spread of antibiotic resistance, the role of physical forces in conjugation is poorly understood. Here we use computer models to show that the conjugative junction not only serves as a link to transfer the DNA but i...

The present review aims to synthesize our present knowledge about the mechanisms implied in the biosynthesis of volatile compounds in the ripe tomato fruit, which have a key role in tomato flavour. The difficulties in identifiying not only genes or genomic regions but also individual target compounds for plant breeding are addressed. Ample variability in the levels of almost any volatile compou...

Escherichia coli K-12 F- mutants defective in conjugation with an I-type donor (ConI-) were isolated and characterized. These mutants are specific in that they are conjugation proficient with other types of donor strains. They have an altered susceptibility to phages and detergents. Chemical analysis of the cell envelopes of mutant strains has shown that the lipopolysaccharide (LPS) is altered ...

Problems emerging from previous analyses of epenthesis in Japanese verbal endings are discussed and a crucial relationship between epenthesis and assimilation is argued. The focus is on the occurrence of /i/-epenthesis with certain root-final consonants. The analysis, which incorporates the view that assimilation is accomplished by means of autosegmental spreading, illustrate* that epenthesis c...

The light scattering effects of turbid media causing opacity may be undone via Optical Phase Conjugation (OPC). Here we rigorously simulate light scattering through a macroscopic random using the pseudospectral time-domain (PSTD) technique. The OPC phenomenon of multiply scattered light can be quantitatively analyzed which is not feasible otherwise. Specifically, factors affecting the electroma...

We study the symmetry behavior of the Gross-Neveu model in three and two dimensions with random chemical potential. This is equivalent to a fourfermion model with charge conjugation symmetry as well as Z2 chiral symmetry. At high temperature the Z2 chiral symmetry is always restored. In three dimensions the initially broken charge conjugation symmetry is not restored at high temperature, irresp...

Small ubiquitin-related modifier-2/3 (SUMO-2/3) is a member of the ubiquitin-like (Ubl) protein family. Conjugation of SUMO-2/3 to target proteins is influenced by various stress conditions and chemical inhibitors. SUMO-2/3 conjugation may serve as a neuroprotective mechanism and may play a role in protein quality control. A method for screening global changes in SUMO-2/3 conjugation would faci...

Molecular electrostatic potentials (MESP) of the most common building blocks of organic π-conjugated systems, viz. ethylene, acetylene, benzene, furan, pyrrole, thiophene and phenylvinylene, are examined at the B3LYP/6-311++G(2d,2p) level. The topography of MESP is employed for mapping the strength of electronic conjugation between these building blocks. When electron-rich molecular regions are...