Lower limb stiffness estimation during running: the effect of using kinematic constraints in muscle force optimization algorithms

The focus of this paper is on the effect of muscle force optimization algorithms on the human lower limb stiffness estimation. By using a forward dynamic neuromusculoskeletal model coupled with a muscle short-range stiffness model we computed the human joint stiffness of the lower limb during running. The joint stiffness values are calculated using two different muscle force optimization procedures, namely: Toque-based and Torque/Kinematic-based algorithm. A comparison between the processed EMG signal and the corresponding estimated muscle forces with the two optimization algorithms is provided. We found that the two stiffness estimates are strongly influenced by the adopted algorithm. We observed different magnitude and timing of both the estimated muscle forces and joint stiffness time profile with respect to each gait phase, as function of the optimization algorithm used

Receptor-dependent phagocytosis of \u3ci\u3eClostridium sordellii\u3c/i\u3e by human decidual macrophages

Clostridium sordellii is an emerging pathogen associated with highly-lethal female reproductive tract (FRT) infections following childbirth, abortion, or cervical instrumentation. Gaps in our understanding of the pathogenesis of C. sordellii infections present major challenges to the development of better preventive and therapeutic strategies against this problem. We sought to determine the mechanisms whereby uterine DMs phagocytose this bacterium and tested the hypothesis that human DMs utilize class A scavenger receptors (CASRs) to internalize unopsonized C. sordellii. In vitro phagocytosis assays with human DMs incubated with pharmacological inhibitors of CASRs (fucoidan, polyinosinic acid, and dextran sulfate) revealed a role for these receptors in C. sordellii phagocytosis. Soluble macrophage receptor with collagenous structure (MARCO) receptor prevented C. sordellii internalization, suggesting that MARCO is an important CASR in DM phagocytosis of this microbe. Peritoneal macrophages from MARCO-deficient mice, but not wild-type or SR-AI/II-deficient mice, showed impaired C. sordellii phagocytosis. MARCOnull mice were more susceptible to death from C. sordellii uterine infection than wild-type mice and exhibited impaired clearance of this bacterium from the infected uterus. Thus, MARCO is an important phagocytic receptor utilized by human and mouse macrophages to clear C. sordellii from the infected uterus

A tunable CMOS constant current source

A constant current source has been designed which makes use of on chip electrically erasable memory to adjust the magnitude and temperature coefficient of the output current. The current source includes a voltage reference based on the difference between enhancement and depletion transistor threshold voltages. Accuracy is +/- 3% over the full range of power supply, process variations, and temperature using eight bits for tuning

Single-trial multisensory memories affect later auditory and visual object discrimination.

Multisensory memory traces established via single-trial exposures can impact subsequent visual object recognition. This impact appears to depend on the meaningfulness of the initial multisensory pairing, implying that multisensory exposures establish distinct object representations that are accessible during later unisensory processing. Multisensory contexts may be particularly effective in influencing auditory discrimination, given the purportedly inferior recognition memory in this sensory modality. The possibility of this generalization and the equivalence of effects when memory discrimination was being performed in the visual vs. auditory modality were at the focus of this study. First, we demonstrate that visual object discrimination is affected by the context of prior multisensory encounters, replicating and extending previous findings by controlling for the probability of multisensory contexts during initial as well as repeated object presentations. Second, we provide the first evidence that single-trial multisensory memories impact subsequent auditory object discrimination. Auditory object discrimination was enhanced when initial presentations entailed semantically congruent multisensory pairs and was impaired after semantically incongruent multisensory encounters, compared to sounds that had been encountered only in a unisensory manner. Third, the impact of single-trial multisensory memories upon unisensory object discrimination was greater when the task was performed in the auditory vs. visual modality. Fourth, there was no evidence for correlation between effects of past multisensory experiences on visual and auditory processing, suggestive of largely independent object processing mechanisms between modalities. We discuss these findings in terms of the conceptual short term memory (CSTM) model and predictive coding. Our results suggest differential recruitment and modulation of conceptual memory networks according to the sensory task at hand

Training product unit neural networks with genetic algorithms

The training of product neural networks using genetic algorithms is discussed. Two unusual neural network techniques are combined; product units are employed instead of the traditional summing units and genetic algorithms train the network rather than backpropagation. As an example, a neural netork is trained to calculate the optimum width of transistors in a CMOS switch. It is shown how local minima affect the performance of a genetic algorithm, and one method of overcoming this is presented

Unstable Dynamics, Nonequilibrium Phases and Criticality in Networked Excitable Media

Here we numerically study a model of excitable media, namely, a network with occasionally quiet nodes and connection weights that vary with activity on a short-time scale. Even in the absence of stimuli, this exhibits unstable dynamics, nonequilibrium phases -including one in which the global activity wanders irregularly among attractors- and 1/f noise while the system falls into the most irregular behavior. A net result is resilience which results in an efficient search in the model attractors space that can explain the origin of certain phenomenology in neural, genetic and ill-condensed matter systems. By extensive computer simulation we also address a relation previously conjectured between observed power-law distributions and the occurrence of a "critical state" during functionality of (e.g.) cortical networks, and describe the precise nature of such criticality in the model.Comment: 18 pages, 9 figure

Excited States in Warm and Hot Dense Matter

Accurate modeling of warm and hot dense matter is challenging in part due to the multitude of excited states that must be considered. In thermal density functional theory, these excited states are averaged over to produce a single, averaged, thermal ground state. Here we present a variational framework and model that includes explicit excited states. In this framework an excited state is defined by a set of effective one-electron occupation factors and the corresponding energy is defined by the effective one-body energy with an exchange and correlation term. The variational framework is applied to an atom-in-plasma model (a generalization of the so-called average atom model). Comparisons with a density functional theory based average atom model generally reveal good agreement in the calculated pressure, but the new model also gives access to the excitation energies and charge state distributions

Evidence for dx2-y2 pairing from nuclear-magnetic-resonance experiments in the superconducting state of YBa2Cu3O7

We calculate the electron spin susceptibility for the superconducting state of YBa2Cu3O7 using a band structure with nearest- and next-nearest-neighbor hopping, a momentum-dependent spin-spin interaction, and a superconducting gap with dx2-y2 symmetry. Our calculated nuclear magnetic relaxation rates and Knight shift agree favorably with experiment. Our work provides further evidence for a dx2-y2 pairing state and demonstrates that antiferromagnetic correlations persist in the superconducting state

Historical-institutionalist perspectives on the development of the EU budget system

The EU budget has only recently started to feature in theories of European integration. Studies typically adopt a historical-institutionalist framework, exploring notions such as path dependency. They have, however, generally been rather aggregated, or coarse-grained, in their approach. The EU budget has thus been treated as a single entity rather than a series of inter-linked institutions. This paper seeks to address these lacunae by adopting a fine-grained approach. This enables us to emphasize the connections that exist between EU budgetary institutions, in both time and space. We show that the initial set of budgetary institutions was unable, over time, to achieve consistently their treaty-based objectives. In response, rather than reform these institutions at potentially high political cost, additional institutions were layered on top of the extant structures. We thus demonstrate how some EU budgetary institutions have remained unchanged, whilst others have been added or changed over time

'She's like a daughter to me': insights into care, work and kinship from rural Russia

This article draws on ethnographic research into a state-funded homecare service in rural Russia. The article discusses intersections between care, work and kinship in the relationships between homecare workers and their elderly wards and explores the ways in which references to kinship, as a means of authenticating paid care and explaining its emotional content, reinforce public and private oppositions while doing little to relieve the tensions and conflicts of care work. The discussion brings together detailed empirical insights into local ideologies and practices as a way of generating new theoretical perspectives, which will be of relevance beyond the particular context of study