Triggering Mechanism for DNA Electrical Conductivity: Reversible Electron Transfer between DNA and Iron Oxide Nanoparticles

A new category of iron oxide nanoparticles (surface active maghemite nanoparticles (SAMNs, γ‐Fe₂O₃)) allows the intimate chemical and electrical contact with DNA by direct covalent binding. On these basis, different DNA‐nanoparticle architectures are developed and used as platform for studying electrical properties of DNA. The macroscopic 3D nanobioconjugate, constituted of 5% SAMNs, 70% water, and 25% DNA, shows high stability, electrochemical reversibility and, moreover, electrical conductivity (70–80 Ω cm^?1). Reversible electron transfer at the interface between nanoparticles and DNA is unequivocally demonstrated by Mössbauer spectroscopy, which shows the appearance of Fe(II) atoms on nanoparticles following nanobioconjugate formation. This represents the first example of permanent electron exchange by DNA, as well as, of DNA conductivity at a macroscopic scale. Finally, the most probable configuration of the binding is tentatively modeled by density functional theory (DFT/UBP86/6‐31+G*), showing the occurrence of electron transfer from the organic orbitals of DNA to surface exposed Fe(III) on nanoparticles, as well as the generation of defects (holes) on the DNA bases. The unequivocal demonstration of DNA conduction provides a new perspective in the five decades long debate about electrical properties of this biopolymer, further suggesting novel approaches for DNA exploitation in nanoelectronics.     

Leaching patterns from wood of different tree species and environmental implications related to wood storage areas

Batch tests were carried out with sawdust obtained from oak (Quercus robur), maple (Acer platanoides), pine (Pinus sylvestris), beech (Fagus sylvatica) and wood chips from oak and pine. Leaching of organic compounds expressed as dissolved organic carbon (DOC) in mg/kg of dry mass took place during the first 24 h. The following additional variables were analysed: pH, conductivity, colour, phenols, tannins and lignin, and biochemical oxygen demand (BOD₇). When leachates obtained with oak wood chips and pine wood chips were compared, no significant difference was observed. However, in batch tests with sawdust, DOC released by oak (90 000 mg/kg) was significantly higher (P = 0.0001) than DOC released by pine (30 000 mg/kg). The results suggest that particle size is not the only variable affecting the leaching of organic compounds from wood. Regarding BOD, colour [platinum‐cobalt (Pt‐Co)], phenols, tannins and lignin, the leaching patterns differed among species, and oak was the species with the highest released values.     

Crash risk and aberrant driving behaviors among bus drivers: The role of personality and attitudes towards traffic safety

Several studies have shown that personality traits and attitudes toward traffic safety predict aberrant driving behaviors and crash involvement. However, this process has not been adequately investigated in professional drivers, such as bus drivers. The present study used a personality–attitudes model to assess whether personality traits predicted aberrant self-reported driving behaviors (driving violations, lapses, and errors) both directly and indirectly, through the effects of attitudes towards traffic safety in a large sample of bus drivers. Additionally, the relationship between aberrant self-reported driving behaviors and crash risk was also assessed.     

Entropy and algorithmic complexity in quantum information theory

A theorem of Brudno says that the entropy production of classical ergodic information sources equals the algorithmic complexity per symbol of almost every sequence emitted by such sources. The recent advances in the theory and technology of quantum information raise the question whether a same relation may hold for ergodic quantum sources. In this paper, we discuss a quantum generalization of Brudno’s result which connects the von Neumann entropy rate and a recently proposed quantum algorithmic complexity.     

The influence of personality factors on visitor attitudes towards adaptivity dimensions for mobile museum guides

In this work, we present a study on adaptation in a mobile museum guide, investigating the relationships between personality traits, and the attitudes towards some basic dimensions of adaptivity. Each participant was exposed to two simulated systems—one adaptive, the other not—on each of the dimensions investigated. The study showed that the personality traits relating to the notion of control (conscientiousness, neuroticism/emotional stability, Locus of Control) have a selective effect on the acceptance of the adaptivity dimensions.