Design and modeling of electrolyte pumping power reduction in redox flow cells

Because of flexible design, long life, and low-cost maintenance, redox flow cell has been recognized as one of the reliable energy storage techniques in remote power systems. In redox flow cells, electrolyte circulation through carbon felt is necessary in order to produce effective ion exchange during the charge and discharge operations. Pumping power required for electrolyte circulation could be significant, especially for multi-stack cell, due to low permeability of the porous carbon felt. Moreover, effective method for transporting bubbles formed inside the electrode is necessary for increasing the effective area of reaction of the electrodes. To further improve the overall performance of the redox flow cells, we proposed several novel designs of electrolyte inlet/outlet port and flow passage in carbon felt intending to reduce the electrolyte pumping power and to increase the effective area. Based on our numerical modeling, it is found that pumping power can be reduced by appropriate inlet/outlet port design and carbon felt with flow channel. The non-uniform flow pattern may cause the bubbles to be carried away from the electrodes effectively. The proposed designs can be applied not only for the single-stack cell but also applicable for the multiple-stacked cells

A Partial-Closure Canonicity Test to Increase the Efficiency of CbO-Type Algorithms

Computing formal concepts is a fundamental part of Formal Concept Analysis and the design of increasingly efficient algorithms to carry out this task is a continuing strand of FCA research. Most approaches suffer from the repeated computation of the same formal concepts and, initially, algorithms concentrated on efficient searches through already computed results to detect these repeats, until the so-called canonicity test was introduced. The canonicity test meant that it was sufficient to examine the attributes of a computed concept to determine its newness: searching through previously computed concepts was no longer necessary. The employment of this test in Close-by-One type algorithms has proved to be highly effective. The typical CbO approach is to compute a concept and then test its canonicity. This paper describes a more efficient approach, whereby a concept need only be partially computed in order to carry out the test. Only if it passes the test does the computation of the concept need to be completed. This paper presents this ‘partial-closure’ canonicity test in the In-Close algorithm and compares it to a traditional CbO algorithm to demonstrate the increase in efficiency

A randomized, placebo-controlled trial of prednisone in early Henoch Schönlein Purpura [ISRCTN85109383]

BACKGROUND: Henoch Schönlein Purpura (HSP) is the most common systemic vasculitis of childhood. There is considerable controversy over whether children with HSP should be treated with corticosteroids. The goal of this study was to investigate whether early corticosteroid administration could reduce the rate of renal or gastrointestinal complications in children with HSP. METHODS: Forty children with HSP, seen in the emergency room of a tertiary-care, paediatric centre, entered a randomized, double-blind, placebo controlled study. The treatment group (n = 21) received oral prednisone, 2 mg/kg/day for one week, with weaning over a second week, while the placebo group (n = 19) received an identical appearing placebo. Co-primary outcomes were the rate of renal involvement at one year and the rate of acute gastrointestinal complications. Co-primary outcomes were analysed using Fisher's Exact test. RESULTS: At one year, there was no difference in the rate of renal involvement (3/21 prednisone group vs. 2/19 placebo group, P = 1.0). There was also no statistically significant difference in the rate of acute gastrointestinal complications (2/21 prednisone group vs. 3/19 placebo group, P = 0.7). Two children in the placebo group did experience intussusceptions compared with none in the prednisone group (P = 0.2). CONCLUSIONS: Early prednisone therapy in HSP does not appear to reduce the risk of renal involvement at one year, or the risk of acute gastrointestinal complications. There may be a reduced risk of intussusception. The routine, early use of prednisone in uncomplicated HSP cannot be recommended at this time

Would the field of cognitive neuroscience be advanced by sharing functional MRI data?

During the past two decades, the advent of functional magnetic resonance imaging (fMRI) has fundamentally changed our understanding of brain-behavior relationships. However, the data from any one study add only incrementally to the big picture. This fact raises important questions about the dominant practice of performing studies in isolation. To what extent are the findings from any single study reproducible? Are researchers who lack the resources to conduct a fMRI study being needlessly excluded? Is pre-existing fMRI data being used effectively to train new students in the field? Here, we will argue that greater sharing and synthesis of raw fMRI data among researchers would make the answers to all of these questions more favorable to scientific discovery than they are today and that such sharing is an important next step for advancing the field of cognitive neuroscience

Background Music Stints Creativity: Evidence from Compound Remote Associate Tasks

Background music has been claimed to enhance people’s creativity (Ritter & Ferguson, 2017). In three experiments we investigated the impact of background music on performance of Compound Remote Associate Tasks (CRATs), which are widely thought to tap creativity. Background music with foreign (unfamiliar) lyrics (Experiment 1), instrumental music without lyrics (Experiment 2), and music with familiar lyrics (Experiment 3) all significantly impaired CRAT performance in comparison to quiet background conditions. Furthermore, Experiment 3 demonstrated that background music impaired CRAT performance regardless of whether the music induced a positive mood or whether participants typically studied in the presence of music. The findings challenge the view that background music enhances creativity, and are discussed in terms of an auditory distraction account (interference-by-process; Jones & Tremblay, 2000) and the processing disfluency account (Mehta et al., 2012)

Does working memory training have to be adaptive?

This study tested the common assumption that, to be most effective, working memory (WM) training should be adaptive (i.e., task difficulty is adjusted to individual performance). Indirect evidence for this assumption stems from studies comparing adaptive training to a condition in which tasks are practiced on the easiest level of difficulty only [cf. Klingberg (Trends Cogn Sci 14:317-324, 2010)], thereby, however, confounding adaptivity and exposure to varying task difficulty. For a more direct test of this hypothesis, we randomly assigned 130 young adults to one of the three WM training procedures (adaptive, randomized, or self-selected change in training task difficulty) or to an active control group. Despite large performance increases in the trained WM tasks, we observed neither transfer to untrained structurally dissimilar WM tasks nor far transfer to reasoning. Surprisingly, neither training nor transfer effects were modulated by training procedure, indicating that exposure to varying levels of task difficulty is sufficient for inducing training gains

Practice Induces Function-Specific Changes in Brain Activity

Practice can have a profound effect on performance and brain activity, especially if a task can be automated. Tasks that allow for automatization typically involve repeated encoding of information that is paired with a constant response. Much remains unknown about the effects of practice on encoding and response selection in an automated task.To investigate function-specific effects of automatization we employed a variant of a Sternberg task with optimized separation of activity associated with encoding and response selection by means of m-sequences. This optimized randomized event-related design allows for model free measurement of BOLD signals over the course of practice. Brain activity was measured at six consecutive runs of practice and compared to brain activity in a novel task.Prompt reductions were found in the entire cortical network involved in encoding after a single run of practice. Changes in the network associated with response selection were less robust and were present only after the third run of practice.This study shows that automatization causes heterogeneous decreases in brain activity across functional regions that do not strictly track performance improvement. This suggests that cognitive performance is supported by a dynamic allocation of multiple resources in a distributed network. Our findings may bear importance in understanding the role of automatization in complex cognitive performance, as increased encoding efficiency in early stages of practice possibly increases the capacity to otherwise interfering information

Zebrafish Krüppel-Like Factor 4a Represses Intestinal Cell Proliferation and Promotes Differentiation of Intestinal Cell Lineages

BACKGROUND:Mouse krüppel-like factor 4 (Klf4) is a zinc finger-containing transcription factor required for terminal differentiation of goblet cells in the colon. However, studies using either Klf4(-/-) mice or mice with conditionally deleted Klf4 in their gastric epithelia showed different results in the role of Klf4 in epithelial cell proliferation. We used zebrafish as a model organism to gain further understanding of the role of Klf4 in the intestinal cell proliferation and differentiation. METHODOLOGY/PRINCIPAL FINDINGS:We characterized the function of klf4a, a mammalian klf4 homologue by antisense morpholino oligomer knockdown. Zebrafish Klf4a shared high amino acid similarities with human and mouse Klf4. Phylogenetic analysis grouped zebrafish Klf4a together with both human and mouse Klf4 in a branch with high bootstrap value. In zebrafish, we demonstrate that Klf4a represses intestinal cell proliferation based on results of BrdU incorporation, p-Histone 3 immunostaining, and transmission electron microscopy analyses. Decreased PepT1 expression was detected in intestinal bulbs of 80- and 102-hours post fertilization (hpf) klf4a morphants. Significant reduction of alcian blue-stained goblet cell number was identified in intestines of 102- and 120-hpf klf4a morphants. Embryos treated with γ-secretase inhibitor showed increased klf4a expression in the intestine, while decreased klf4a expression and reduction in goblet cell number were observed in embryos injected with Notch intracellular domain (NICD) mRNA. We were able to detect recovery of goblet cell number in 102-hpf embryos that had been co-injected with both klf4a and Notch 1a NICD mRNA. CONCLUSIONS/SIGNIFICANCE:This study provides in vivo evidence showing that zebrafih Klf4a is essential for the repression of intestinal cell proliferation. Zebrafish Klf4a is required for the differentiation of goblet cells and the terminal differentiation of enterocytes. Moreover, the regulation of differentiation of goblet cells in zebrafish intestine by Notch signaling at least partially mediated through Klf4a

Point contact Andreev reflection spectroscopy of NdFeAsO_0.85

The newly discovered oxypnictide family of superconductors show very high critical temperatures of up to 55K. Whilst there is growing evidence that suggests a nodal order parameter, point contact Andreev reflection spectroscopy can provide crucial information such as the gap value and possibly the number of energy gaps involved. For the oxygen deficient NdFeAsO0.85 with a Tc of 45.5K, we show that there is clearly a gap value at 4.2K that is of the order of 7meV, consistent with previous studies on oxypnictides with lower Tc. Additionally, taking the spectra as a function of gold tip contact pressure reveals important changes in the spectra which may be indicative of more complex physics underlying this structure.Comment: 11 pages, 3 figures. New references included, extra discussion. This version is accepted in Superconductor Science and Technolog