Cortical alpha activity predicts the confidence in an impending action

When we make a decision, we experience a degree of confidence that our choice may lead to a desirable outcome. Recent studies in animals have probed the subjective aspects of the choice confidence using confidence-reporting tasks. These studies showed that estimates of the choice confidence substantially modulate neural activity in multiple regions of the brain. Building on these findings, we investigated the neural representation of the confidence in a choice in humans who explicitly reported the confidence in their choice. Subjects performed a perceptual decision task in which they decided between choosing a button press or a saccade while we recorded EEG activity. Following each choice, subjects indicated whether they were sure or unsure about the choice. We found that alpha activity strongly encodes a subject's confidence level in a forthcoming button press choice. The neural effect of the subjects' confidence was independent of the reaction time and independent of the sensory input modeled as a decision variable. Furthermore, the effect is not due to a general cognitive state, such as reward expectation, because the effect was specifically observed during button press choices and not during saccade choices. The neural effect of the confidence in the ensuing button press choice was strong enough that we could predict, from independent single trial neural signals, whether a subject was going to be sure or unsure of an ensuing button press choice. In sum, alpha activity in human cortex provides a window into the commitment to make a hand movement

Comparability of antibody response to a booster dose of 7-valent pneumococcal conjugate vaccine in infants primed with either 2 or 3 doses

In this cohort study we compared IgG antibody levels between infants immunized with 7-valent CRM197-conjugated pneumococcal vaccine (PCV-7) at 2,4 and 11 months and at 2, 3, 4 and 11 months of age,as measured by double adsorption ELISA. Pre- and post-booster levels following the 2 + 1 - and 3 + 1-dose schedule were comparable for 5 out of 7 serotypes except for serotypes 6B and 19F. The proportion of children reaching post-booster antibody thresholds were comparable except for 6B (>= 1.0 mu g/ml and >= 5.0 mu g/ml) and 19F (>= 5.0 mu g/ml). Surveillance studies are warranted for vaccine impact on 6B and 19F disease cases after reduced-dose PCV-7 schedules. (C) 2009 Elsevier Ltd. All rights reserved

Trap-Assisted Charge Generation and Recombination in State-of-the-Art Organic Photodetectors

The performance of organic photodetectors is steadily improving, and the specific detectivity, as a key figure of merit, has reached values of 1012–1013 Jones, i.e., comparable to that of silicon diodes but still considerably lower than the intrinsic limit. As with other semiconductor devices, the electrical performance of state-of-the art organic photodiodes (OPDs) is presently determined to a high degree by the presence of chemical impurities or structural defects which create carrier trapping states within the bandgap of organic active layer. This review aims to provide a comprehensive and timely account of trap-assisted charge generation and recombination in OPDs, with emphasis on the impact of these phenomena on photodetector performance parameters such as, noise and dark current density, responsivity, response speed, and ultimately, specific detectivity.</p

Consensus guidelines for lumbar puncture in patients with neurological diseases

Introduction Cerebrospinal fluid collection by lumbar puncture (LP) is performed in the diagnostic workup of several neurological brain diseases. Reluctance to perform the procedure is among others due to a lack of standards and guidelines to minimize the risk of complications, such as post-LP headache or back pain. Methods We provide consensus guidelines for the LP procedure to minimize the risk of complications. The recommendations are based on (1) data from a large multicenter LP feasibility study (evidence level II-2), (2) systematic literature review on LP needle characteristics and post-LP complications (evidence level II-2), (3) discussion of best practice within the Joint Programme Neurodegenerative Disease Research Biomarkers for Alzheimer's disease and Parkinson's Disease and Biomarkers for Multiple Sclerosis consortia (evidence level III). Results Our consensus guidelines address contraindications, as well as patient-related and procedure-related risk factors that can influence the development of post-LP complications. Discussion When an LP is performed correctly, the procedure is well tolerated and accepted with a low complication rate

Quantitative loss analysis of opaque perovskite solar cells using transient and steady-state characterization

Perovskite solar cells have emerged as a promising technology in the field of photovoltaics, owing to their notable advancements in power-conversion efficiency. Recent investigations have revealed a crucial dependency of efficiency on the source of bromide within the perovskite absorption layer. To elucidate the underlying nature of traps within these solar cells, a comprehensive series of measurements was conducted under varying light intensities. Subsequently, employing an electrodynamic theoretical model, the intrinsic processes inherent to caesium and lead-based perovskite solar cells with different bromide sources were analyzed. The study reveals significant differences in transient photocurrent measurements and photocurrent-voltage characteristics among perovskites originating from different bromide sources, measured under different light intensities. Leveraging theoretical analyses on the picosecond scale, the recombination mechanism of crystal defects was meticulously described revealing the pronounced influence of capture rates on electron-hole recombination dynamics. Furthermore, the investigation substantiated the presence of a band-bending phenomenon at the interface between the hole transport layer (HTL) and perovskite, elucidating the observed transient photocurrent phenomena. The findings significantly advance the understanding of the mechanisms underlying perovskite solar cells, offering valuable insights into their performance and paving the way for enhanced efficiency and stability in future device design and optimization.</p

Multi-commodity support in profile steering

The interest in hybrid energy systems that coordinate multiple commodities simultaneously on residential level (e.g., electricity, heat, gas) is increasing. Such systems can benefit from the synergy between energy carriers to improve the overall energy system efficiency. However, dependencies between commodities make optimisation of such a system generally hard. This paper presents a planning-based multi-commodity energy management system that scales linearly with the number of commodities and connected devices. We apply our approach to balance the three phases in a low voltage grid while charging a fleet of electric vehicles. Simulation results show that our approach is capable of balancing the three phases in this network to enhance the delivered power quality. This balancing also results in a decrease of distribution losses of up to 41.2% compared to a control strategy that does not consider multiple commodities and phase balancing

Flexible Abstraction Layers for VR application development

The development of domain-specific Virtual Reality applications is often a slow and laborious process. The integration of the domain-specific functionality in an interactive Virtual Environment requires close collaboration between domain expert and VR developer, as well as the integration of domain-specific data and software in a VR application. The software environment needs to support the entire development process and software life cycle, from the early stages of iterative, rapid prototyping to a final end-user application. In this paper, we propose the use of flexible abstraction layers in the form of a dynamic scripting language, which act as the glue between VR system components and external software libraries and applications. First, we discuss the motivation and potential of our approach, after which we overview related approaches. Then, we describe the integration of a Python interpreter in our VR toolkit. The potential of our integration approach is demonstrated by rapid prototyping features, the flexible extension of core functionality and the integration of an external toolkit. We conclude with an overview of implications our approach has for the future development of new framework features and application integration

TINTE - nuclear calculation theory description report

The Time Dependent Neutronics and Temperatures (TINTE) code system deals with the nuclear and the thermal transient behaviour of the primary circuit of the High-temperature Gas-cooled Reactor (HTGR), taking into consideration the mutual feedback effects in twodimensional axisymmetric geometry. This document contains a complete description of the theoretical basis of the TINTE nuclear calculation, including the equations solved, solution methods and the nuclear data used in the solution. This document was prepared in compliance with the layout and review requirements of [1] and [2], and forms part of the verification and validation of TINTE

TINTE - A two-dimensional code for reactor dynamics

The TINTE main documentation consists of three parts, the first two of which/1/,/2/ have been published (in German) in the late eighties. In the first part the problems of modelling the nuclear and thermo-gas-dynamic behaviour of the primary circuit of a high temperature gas cooled reactor (HTGR) have been discussed in detail. It has been explained how the multiconnected system can be decomposed into single tasks to be solved separately. The solution of the total system is thus found by iteration of the partial results. In the second part of the documentation some major applications of TINTE are demonstrated. Among them the analyses of dynamic reactor experiments performed at the AVR reactor /4/ are of special interest. These results play a major role in the TINTE validation process, and the very good conformance obtained with the experimental data validate the TINTE calculations to a considerable extent. Earlier post-calculations of the AVR experiments with a previous version of the TINTE code have been described in /5/. Moreover, the basic algorithms as used in TINTE together with some applications have been shown in /4/. Since not all of the capabilities of TINTE could be addressed in these analysis, the validation process was continued, e.g. with the evaluation of the VELUNA corrosion experiments /6/. An addendum to the principal considerations of /1/ has been added as a supplement to /2/. Here the gas flow in an optional 1-D component and flow network is described, which may be used to enhance the 2-D reactor model for special situations. This flow network was necessary to model non-central pipes and other three-dimensional gas flow paths. It allows the description of co-axial pipes and a lumped parameter simulation of the primary side ofheat exchangers or steam generators. One example in /4/ shows that under certain limitations even a simulation of a gas-gas heat exchanger and the incorporation of the secondary loop is possible with the aid of that flow-network. In this addendum the possibility is also introduced to calculate the pressure inside the reactorfrom a given (fixed or variable in time) gas inventory. This is of relevance for accident analyses, where a failure of the pressure enclosure is assumed. If the pressure increases significantly gas may be removed from the system by burst discs or safety valves. This document starts with a description of the TINTE code structure (Section 4), while Section 5 is dedicated to the description and interpretation of the main input data. Section 6 deals with the preparation of the nuclear data base, the generation of the cross-section polynomial expansions and the necessary interface codes. Aspects included here are the evaluation of nuclide vectors (prepared by burn-up codes) and the preparation of spectrum calculations with variation of temperatures, buckling and concentrations for spectrum relevant nuclides. User notes on the code installation and calculational procedures are presented in Section 7, while Sections 8 and 9 discuss the TINTE control options and output data options, respectively. Section 10 lists the changes made in the TINTE source code over the years. The report also includes in the Appendices some newer algorithms for the treatment of special situations, while a description of the correlations used for the heat capacities and thermal conductivities are also given. Of special note here is Appendix E, which lists the detail of the ROMO model newly implemented in TINTE in 2004