When external stresses in a system-physical, social or virtual-are relieved through impulsive events, it is natural to focus on the attributes of these avalanches. However, during the quiescent periods between them, stresses may be relieved through competing processes, such as slowly flowing water between earthquakes or thermally activated dislocation flow between plastic bursts in crystals. Such smooth responses can in turn have marked effects on the avalanche properties.

We report the room temperature formation of aminated mesoporous silica nanoparticles (NH 2-MSNs) by means of co-condensation of different molar ratios of tetraethyl orthosilicate (TEOS) and 3-aminopropyl triethoxysilane (APTES) in the synthesis feed. The resulting materials are characterized by a combination of transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and N 2 adsorption/desorption measurements.

We study the primary root growth of wild-type Medicago truncatula plants in heterogeneous environments using 3D time-lapse imaging. The growth medium is a transparent hydrogel consisting of a stiff lower layer and a compliant upper layer. We find that the roots deform into a helical shape just above the gel layer interface before penetrating into the lower layer. This geometry is interpreted as a combination of growth-induced mechanical buckling modulated by the growth medium and a simultaneous twisting near the root tip.

Many correlated materials display a quantum-critical point between a paramagnetic and a spin-density wave (SDW) state. The SDW wave vector connects points, so-called hot spots, on opposite sides of the Fermi surface. The Fermi velocities at these pairs of points are in general not parallel. Here, we consider the case where pairs of hot spots coalesce, and the wave vector (π,π) of the SDW connects hot spots with parallel Fermi velocities.

New approaches for optical data storage (ODS) applications are needed to meet the future requirements of applications in multimedia, archiving, security, and many others. Commercial data storage technologies are moving to threedimensional (3D) materials, but the capacity is limited by the fabrication cost and the number of layers that can be addressed using the reflection-based storage mechanism. We demonstrate here storage systems based on co-extrusion of multilayer (ML) films that can overcome these problems.

Single-molecule techniques reveal short- and long-range dynamics of supercoiled DNA.

3D Optical data storage is demonstrated in co-extruded multilayer films using organic materials. Co-extrusion is able to produce films on a much larger scale at a much lower cost than current methods. The material compatibility and mechanical flexibility allow for new data formats with higher capacities to be realized. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

We have examined a promising family of radio frequency coaxial connectors (the SSMCX range) suitable for use at low temperatures. We describe the measured characteristics of these connectors in typical arrangements using lossy Cooner stainless steel inner and outer (braided) coaxial cable and other specialty low temperature coaxial cables including Beryllium Copper (BeCu) outer and inner conductors, Copper Nickel (CuNi) outer and Niobium–Titanium (NbTi) superconducting inner conductors, and Nb outer/NbTi inner conductor (homemade) cables.

The computational evolution of gene networks functions like a forward genetic screen to generate, without preconceptions, all networks that can be assembled from a defined list of parts to implement a given function. Frequently networks are subject to multiple design criteria that cannot all be optimized simultaneously. To explore how these tradeoffs interact with evolution, we implement Pareto optimization in the context of gene network evolution.

Controlling the electronic properties of interfaces has enormous scientific and technological implications and has been recently extended from semiconductors to complex oxides that host emergent ground states not present in the parent materials. These oxide interfaces present a fundamentally new opportunity where, instead of conventional bandgap engineering, the electronic and magnetic properties can be optimized by engineering quantum many-body interactions.