Bill-EVR: an embodied virtual reality framework for reward-and-error-based motor rehab-learning

VR rehabilitation is an established field by now, however, it often refers to computer screen-based interactive rehabilitation activities. In recent years, there was an increased use of VR-headsets, which can provide an immersive virtual environment for real-world tasks, but they are lacking any physical interaction with the task objects and any proprioceptive feedback. Here, we focus on Embodied Virtual Reality (EVR), an emerging field where not only the visual input via VR-headset but also the haptic feedback is physically correct. This happens because subjects interact with physical objects that are veridically aligned in Virtual Reality. This technology lets us manipulate motor performance and motor learning through visual feedback perturbations. Bill-EVR is a framework that allows interventions in the performance of real-world tasks, such as playing pool billiard, engaging end-users in motivating life-like situations to trigger motor (re)learning - subjects see in VR and handle the real-world cue stick, the pool table and shoot physical balls. Specifically, we developed our platform to isolate and evaluate different mechanisms of motor learning to investigate its two main components, error-based and reward-based motor adaptation. This understanding can provide insights for improvements in neurorehabilitation: indeed, reward-based mechanisms are putatively impaired by degradation of the dopaminergic system, such as in Parkinson's disease, while error-based mechanisms are essential for recovering from stroke-induced movement errors. Due to its fully customisable features, our EVR framework can be used to facilitate the improvement of several conditions, providing a valid extension of VR-based implementations and constituting a motor learning tool that can be completely tailored to the individual needs of patients

Investor protection through model case procedures – implementing collective goals and individual rights under the 2012 Amendment of the German Capital Markets Model Case Act (KapMuG)

The German Capital Markets Model Case Act (KapMuG) and its amendment of 2012 highlight some fundamentals of collective redress in civil law countries at the example of model case procedures in the field of investor protection. That is why a survey of the ongoing activities of the European Union in the area of collective redress and of its repercussions on the member state level forms a suitable basis for the following analysis of the 2012 amendment of the KapMuG. It clearly brings into focus a shift from sector-specific regulation with an emphasis on the cross-border aspect of protecting consumers towards a “coherent approach” strengthening the enforcement of EU law. As a result, regulatory policy and collective redress are two sides of the same coin today. With respect to the KapMuG such a development brings about some tension between its aim to aggregate small individual claims as efficiently as possible and the dominant role of individual procedural rights in German civil procedure. This conflict can be illustrated by some specific rules of the KapMuG: its scope of application, the three-tier procedure of a model case procedure, the newly introduced notification of claims and the new opt-out settlement under the amended §§ 17-19

Linear Continuum Mechanics for Quantum Many-Body Systems

We develop the continuum mechanics of quantum many-body systems in the linear response regime. The basic variable of the theory is the displacement field, for which we derive a closed equation of motion under the assumption that the time-dependent wave function in a locally co-moving reference frame can be described as a geometric deformation of the ground-state wave function. We show that this equation of motion is exact for systems consisting of a single particle, and for all systems at sufficiently high frequency, and that it leads to an excitation spectrum that has the correct integrated strength. The theory is illustrated by simple model applications to one- and two-electron systems.Comment: 4 pages, 1 figure, 1 tabl

Artery/vein classification using reflection features in retina fundus images

Automatic artery/vein (A/V) classification is one of the important topics in retinal image analysis. It allows the researchers to investigate the association between biomarkers and disease progression on a huge amount of data for arteries and veins separately. Recent proposed methods, which employ contextual information of vessels to achieve better A/V classification accuracy, still rely on the performance of pixel-wise classification, which has received limited attention in recent years. In this paper, we show that these classification methods can be markedly improved. We propose a new normalization technique for extracting four new features which are associated with the lightness reflection of vessels. The accuracy of a linear discriminate analysis classifier is used to validate these features. Accuracy rates of 85.1, 86.9 and 90.6% were obtained on three datasets using only local information. Based on the introduced features, the advanced graph-based methods will achieve a better performance on A/V classification.</p

Standardization of serum cholesterol assays by use of serum calibrators and direct addition of Liebermann-Burchard reagent

Serum cholesterol concentrations of subjects in epidemiological studies were measured after direct addition of Liebermann-Burchard reagent; results were calibrated with human serum pools assayed according to Abell et al. (J. Biol. Chem. 195:357-366, 1952). Accuracy and precision were monitored for six years by analysis of internal-control pools and blind external-control pools. For various internal-control pools, the imprecision (CV) of the long-term averages of run means ranged from 0.5 to 0.9%. The within-run CV for internal control and patients' sera was about 1%. For blind control sera with different concentrations (provided by the Centers for Disease Control, Atlanta, GA, over the same period), the average difference per three-month period between the values found and the target values was usually between -0.5% and 0.7% for medium-concentration pools and between -2% and 2% for low- and high-concentration pools (extreme values: -2.4% and 2.5%). The CV per three-month period ranged from 0.6 to 2.7%. Sera from subjects on diets of high or low linoleic acid content were analyzed to study the effect of the fatty acid portion of serum cholesterol esters; the differences between values obtained with the comparison method and the direct method was insignificant on both diets. We conclude that the use of serum calibrators eliminates the bias inherent in the direct method

Spectroscopy on two coupled flux qubits

We have performed spectroscopy measurements on two coupled flux qubits. The qubits are coupled inductively, which results in a $\sigma_1^z\sigma_2^z$ interaction. By applying microwave radiation, we observe resonances due to transitions from the ground state to the first two excited states. From the position of these resonances as a function of the magnetic field applied we observe the coupling of the qubits. The coupling strength agrees well with calculations of the mutual inductance

Mesoscale analysis by numerical modeling coupled with satellite-based sounding

November 1988.Principal investigators: Thomas H. Vonder Haar, James F.W. Purdom.Includes bibliographical references.This dissertation deals with the development of a system for time-continuous mesoscale analysis and its use in studying the mesoscale distribution of summertime convective cloud development in the Northeastern Colorado region. There were two basic components of the system — a version of the CSU Regional Atmospheric Modeling System (RAMS) and an algorithm for retrieving temperatures and water vapor concentrations from VISSR Atmospheric Sounder (VAS) data. The system was designed to avoid some of the problems that researchers have encountered when satellite-retrieved parameters have been input to models. The primary distinguishing feature of the new method is that there is an intimate coupling of the retrieval and modeling processes. Water vapor concentrations and ground surface temperatures were the foci of the analyses. In preparation for analysis experiments we tested the sensitivity of a two-dimensional version of the model to various controls on the behavior of water vapor concentrations and surface temperatures. For water vapor mixing ratios, variations that might be caused by analysis errors had very little impact on the dynamics of circulations in the pre-convective stage. In contrast, ground surface temperature variations were shown to have a large impact on circulations, so analysis errors are very relevant to pre-convective dynamics. The first comparisons of the coupled analysis method with other, related, methods was by means of two-dimensional simulations. Analyses in which surface temperatures were derived from satellite-retrievals were compared with the alternative of relying on energy balance computations. The energy balance computations were so sensitive to soil characteristics, which were simulated as unknown, that the satellite retrieval method gave better results even with cloud contamination. In water vapor analysis comparisons no single method was superior in every respect, but the coupled method performed relatively well. Vertical gradients and horizontal gradients were well represented, and the method was relatively insensitive to a common problem in pre-convective analysis — contamination of satellite data by increasing amounts of small convective clouds. Analysis methods were further compared in a three-dimensional case study for 21 August 1983. The horizontal and time variations of satellite-retrieved surface temperatures closely corresponded to the conventional shelter temperature observations, but had much greater detail. In contrast, the energy balance-based temperatures tended to increase too quickly during the morning and lacked some of the observed gradients. According to the retrievals, there can be very large mesoscale gradients in temperatures at the ground surface even on the relatively flat plains. In the case study water vapor analyses there were substantial differences among the results of the several methods that were intercompared. The study demonstrated that, when the first set of satellite data is less reliable than the later sets, some of the contamination lingers throughout the time-continuous coupled analysis results. However, the coupled method generally appeared to be the most valuable of the methods considered in this study because it exploited the major strengths of the numerical model and the satellite data while making it relatively easy to recognize any impacts of their weaknesses. The results of this dissertation support the hypothesis that both ground surface temperatures and terrain variations can play important roles in pre-convective water vapor kinematics through their influences on vertical and horizontal winds. The development of convective clouds corresponded largely, but not exclusively, with convergence and deepening of low-level water vapor. The analysis system proved to be valuable for forecasting through the close correspondence between derived stability indices and later convective development. The new method is a step in the expanding capability of meteorologists to combine tools and sources of data for understanding and forecasting mesoscale phenomena.Research supported by National Oceanic and Atmospheric Administration Grant NA-85-RAH-05045 (53-1209) and in part by Army Research Office Center for Geosciences, Grant DALL-03-86-K-9175