Reducing the energy cost of human walking using an unpowered exoskeleton

Walking is the most commonplace of activities, yet we know remarkably little about it and no robot has yet reproduced the grace and poise of a human walk. Steven Collins et al. now show that the attachment of a simple mechanical exoskeleton to the foot and ankle results in a 7 reduction of the metabolic energy expended in walking. This work shows that net energy input is not a fundamental requirement for reducing the metabolic cost of human walking, and that reducing calf muscle forces while also fulfilling normal ankle functions and minimizing penalties associated with added mass or restricted motions can be beneficial

A study of the damping-off disease of coniferous seedlings

This archival publication may not reflect current scientific knowledge or recommendations

The medical student

The Medical Student was published from 1888-1921 by the students of Boston University School of Medicine

A pragmatic cognitive model for the interpretation of verbal–visual communication in television news programmes

The combination of the verbal and the visual track in television news discourse poses a considerable analytical challenge. In the viewers’ minds the co-habitation of these two semiotic channels triggers a complex network of inferential processes, based on expectations of coherence and relevance, with which they make sense of the representation of the world offered in the news. Through the analysis of a number of news items, this article considers the cognitive processes which viewers may activate when extracting meaning from the multimedial messages contained in television news. The analysis of news items from two British television networks offered by the authors traces the possible meanings that, it is assumed, become available to a potential, ‘idealised’ or ‘implied’ viewer, who accesses the information with some social and cultural knowledge of contemporary Britain. Building on existing studies, the article proposes a model for the classification of verbal–visual relations

Planning Framework Options for The Massachusetts Ocean Plan (DRAFT)

The Massachusetts Ocean Partnership (MOP) Planning Frameworks Team, in consultation with the Massachusetts Executive Office of Energy and Environmental Affairs (EEA), and based on collective experience and a review of ocean, coastal and resource management programs from the US and other countries, suggests that nine elements are essential components of the framework for the Massachusetts Ocean Plan and its implementation. While management plans and programs generally have these elements in common, there are a range of options for carrying out each program component. These options were presented to structure and inform the development of the Massachusetts Ocean Plan. For the most part, the range of options represents those that were considered to be appropriate under the Commonwealth’s existing legal and administrative structure and responsive to the requirements of the Massachusetts Ocean Act. However, the general concepts these options represent are likely to be transferable to other jurisdictions (especially in the United States) and can inform future ocean management and planning in Massachusetts. Additionally, options or their core elements can be combined to create additional alternatives within one of the nine planning components

Dendrimers in Nanoscale Confinement: The Interplay between Conformational Change and Nanopore Entrance

Hyperbranched dendrimers are nanocarriers for drugs, imaging agents, and catalysts. Their nanoscale confinement is of fundamental interest and occurs when dendrimers with bioactive payload block or pass biological nanochannels or when catalysts are entrapped in inorganic nanoporous support scaffolds. The molecular process of confinement and its effect on dendrimer conformations are, however, poorly understood. Here, we use single-molecule nanopore measurements and molecular dynamics simulations to establish an atomically detailed model of pore dendrimer interactions. We discover and explain that electrophoretic migration of polycationic PAMAM dendrimers into confined space is not dictated by the diameter of the branched molecules but by their size and generation-dependent compressibility. Differences in structural flexibility also rationalize the apparent anomaly that the experimental nanopore current read-out depends in nonlinear fashion on dendrimer size. Nanoscale confinement is inferred to reduce the protonation of the polycationic structures. Our model can likely be expanded to other dendrimers and be applied to improve the analysis of biophysical experiments, rationally design functional materials such as nanoporous filtration devices or nanoscale drug carriers that effectively pass biological pores