On the importance of low-energy beta beams for supernova neutrino physics

We argue that isotropization and, consequently, thermalization of the system of gluons and quarks produced in an ultrarelativistic heavy-ion collision does not follow from Feynman diagram analysis to any order in the coupling constant. We conclude that the apparent thermalization of quarks and gluons, leading to success of perfect fluid hydrodynamics in describing heavy-ion collisions at RHIC, can only be attributed to the non-perturbative QCD effects not captured by Feynman diagrams. We proceed by modeling these non-pertrubative thermalization effects using viscous hydrodynamics. We point out that matching Color Glass Condensate inital conditions with viscous hydrodynamics leads to a continuous evolution of all the components of the energy-momentum tensor and, unlike the case of ideal hydrodynamics, does not give rise to a discontinuity in the longitudinal pressure. An important consequence of such a matching is a relationship between the thermalization time and shear viscosity: we observe that small viscosity leads to short thermalization time.     

Frequency-coded quantum key distribution

We report an intrinsically stable quantum key distribution scheme based on genuine frequency-coded quantum states. The qubits are efficiently processed without fiber interferometers by fully exploiting the nonlinear interaction occurring in electro-optic phase modulators. The system requires only integrated off-the-shelf devices and could be used with a true single-photon source. Preliminary experiments have been performed with weak laser pulses and have demonstrated the feasibility of this new setup.     

Supramolecular DNA assembly

The powerful self-assembly features of DNA make it a unique template to finely organize and control matter on the nanometre scale. While DNA alone offers a high degree of fidelity in its self-assembly, a new area of research termed 'supramolecular DNA assembly' has recently emerged. This field combines DNA building blocks with synthetic organic, inorganic and polymeric structures. It thus brings together the toolbox of supramolecular chemistry with the predictable and programmable nature of DNA. The result of this molecular partnership is a variety of hybrid architectures, that expand DNA assembly beyond the boundaries of Watson-Crick base pairing into new structural and functional properties. In this tutorial review we outline this emerging field of study, and describe recent research aiming to synergistically combine the properties inherent to DNA with those of a number of supramolecular scaffolds. This ultimately creates structures with numerous potential applications in materials science, catalysis and medicine.     

Potential application of Raman spectroscopy for determining burial duration of skeletal remains

Raman spectroscopy was used to study trends in chemical composition of bones in a burial environment. A turkey bone was sectioned and buried for short intervals between 12 and 62 days. Buried sections were analyzed using Raman microspectroscopy with 785 nm excitation. The results indicate that chemical changes in bone due to soil bacteria are time-dependent. Spectroscopic trends within buried bone segments were correlated to burial duration. A preliminary model was constructed using peak integration of Raman bands. Data collected within buried bone segments fit very well in this model. The model constructed is sensitive to changes in bone composition in a scale of days. This study illustrates the great potential of Raman spectroscopy as a non-destructive method for estimating the burial duration of bone for forensic purposes.     

Stability of DNA containing a structural water mimic in an A-T rich sequence

We describe here the synthesis and properties of A-T rich DNA containing covalently bound water mimics located in the DNA minor groove.