Hepatitis C virus helicase is a molecular motor that splits duplex DNA while actively moving over it. An approximate coarse-grained dynamical description of this protein, including its interactions with DNA and ATP, is constructed. Using such a mechanical model, entire operation cycles of an important protein machine could be followed in structurally resolved dynamical simulations. Ratcheting i...

Surface ratchets can guide droplet transport for microfluidic systems. Here, we demonstrated the actuation of microgels encapsulated in droplets using a unidirectional nanotextured surface, which moves droplets with low vibration amplitudes by a ratcheting mechanism. The nanofilm carries droplets along the ratchets with minimal drop shape deformation to move the encapsulated soft cargo, i.e., m...

Inspired by the locomotion of terrestrial limbless animals, we study the motion of a lubricated rod of a hydrogel on a soft substrate. We show that it is possible to mimic observed biological gaits by vibrating the substrate and by using a variety of mechanisms to break longitudinal and lateral symmetry. Our simple theory and experiments provide a unified view of the creeping, undulating, and i...

Some researchers have claimed that chimpanzee and human culture rest on homologous cognitive and learning mechanisms. While clearly there are some homologous mechanisms, we argue here that there are some different mechanisms at work as well. Chimpanzee cultural traditions represent behavioural biases of different populations, all within the species' existing cognitive repertoire (what we call t...

We have developed a non-steady-state mathematical model describing post-translational protein translocation across the endoplasmic reticulum membrane. Movement of the polypeptide chain through the channel in the endoplasmic reticulum membrane is considered to be a stochastic process which is biased at the lumenal side of the channel by the binding of BiP (Kar2p), a member of the Hsp70 family of...

This review examines some recent work on robust heteroclinic networks that can appear as attractors for coupled dynamical systems. We focus on coupled phase oscillators and discuss a number of nonlinear dynamical phenomena that are atypical in systems without some coupling structure. The phenomena we discuss include heteroclinic cycles and networks between partially synchronized states. These n...

Accurate analysis of plastic strain accumulation under stress-controlled cyclic loading is vital for numerous engineering applications. Typically, models ratcheting are calibrated against available experimental data. Since actual experiments not exactly accurate, one should check the identification protocols pathological dependencies on errors. In this paper, a step-by-step algorithm presented ...

A long-time dynamic for granular materials arising in the hypoplastic theory of Kolymbas type is investigated. It assumed that hardness allows exponential degradation, which leads to densification material states. The governing system a rate-independent strain under stress control described by implicit differential equations. Its analytical solution arbitrary inhomogeneous coefficients construc...

Accounting educators struggle with ways to incorporate the development of critical thinking and communication skills into the curriculum. Case analysis is one tool for developing these skills. We examine whether students’ case analysis scores improve as a result of participation in peer grading and peer review. We find that students improve their ability to perform case analyses after both eval...

Intensification of poverty and degradation of health infrastructure over recent decades in countries most affected by HIV/AIDS present formidable challenges to clinical research. This paper addresses the overall standard of health care (SOC) that should be provided to research participants in developing countries, rather than the narrow definition of SOC that has characterised the international...