Causal contribution and dynamical encoding in the striatum during evidence accumulation.

A broad range of decision-making processes involve gradual accumulation of evidence over time, but the neural circuits responsible for this computation are not yet established. Recent data indicate that cortical regions that are prominently associated with accumulating evidence, such as the posterior parietal cortex and the frontal orienting fields, may not be directly involved in this computation. Which, then, are the regions involved? Regions that are directly involved in evidence accumulation should directly influence the accumulation-based decision-making behavior, have a graded neural encoding of accumulated evidence and contribute throughout the accumulation process. Here, we investigated the role of the anterior dorsal striatum (ADS) in a rodent auditory evidence accumulation task using a combination of behavioral, pharmacological, optogenetic, electrophysiological and computational approaches. We find that the ADS is the first brain region known to satisfy the three criteria. Thus, the ADS may be the first identified node in the network responsible for evidence accumulation

Introducing an Artificial Deazaflavin Cofactor in Escherichia coli and Saccharomyces cerevisiae

[Image: see text] Deazaflavin-dependent whole-cell conversions in well-studied and industrially relevant microorganisms such as Escherichia coli and Saccharomyces cerevisiae have high potential for the biocatalytic production of valuable compounds. The artificial deazaflavin FOP (FO-5′-phosphate) can functionally substitute the natural deazaflavin F(420) and can be synthesized in fewer steps, offering a solution to the limited availability of the latter due to its complex (bio)synthesis. Herein we set out to produce FOP in vivo as a scalable FOP production method and as a means for FOP-mediated whole-cell conversions. Heterologous expression of the riboflavin kinase from Schizosaccharomyces pombe enabled in vivo phosphorylation of FO, which was supplied by either organic synthesis ex vivo, or by a coexpressed FO synthase in vivo, producing FOP in E. coli as well as in S. cerevisiae. Through combined approaches of enzyme engineering as well as optimization of expression systems and growth media, we further improved the in vivo FOP production in both organisms. The improved FOP production yield in E. coli is comparable to the F(420) yield of native F(420)-producing organisms such as Mycobacterium smegmatis, but the former can be achieved in a significantly shorter time frame. Our E. coli expression system has an estimated production rate of 0.078 μmol L(–1) h(–1) and results in an intracellular FOP concentration of about 40 μM, which is high enough to support catalysis. In fact, we demonstrate the successful FOP-mediated whole-cell conversion of ketoisophorone using E. coli cells. In S. cerevisiae, in vivo FOP production by SpRFK using supplied FO was improved through media optimization and enzyme engineering. Through structure-guided enzyme engineering, a SpRFK variant with 7-fold increased catalytic efficiency compared to the wild type was discovered. By using this variant in optimized media conditions, FOP production yield in S. cerevisiae was 20-fold increased compared to the very low initial yield of 0.24 ± 0.04 nmol per g dry biomass. The results show that bacterial and eukaryotic hosts can be engineered to produce the functional deazaflavin cofactor mimic FOP

Polymicrobial periodontal disease triggers a wide radius of effect and unique virome.

Periodontal disease is a microbially-mediated inflammatory disease of tooth-supporting tissues that leads to bone and tissue loss around teeth. Although bacterially-mediated mechanisms of alveolar bone destruction have been widely studied, the effects of a polymicrobial infection on the periodontal ligament and microbiome/virome have not been well explored. Therefore, the current investigation introduced a new mouse model of periodontal disease to examine the effects of a polymicrobial infection on periodontal ligament (PDL) properties, changes in bone loss, the host immune response, and the microbiome/virome using shotgun sequencing. Periodontal pathogens, namely Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Fusobacterium nucleatum were used as the polymicrobial oral inoculum in BALB/cByJ mice. The polymicrobial infection triggered significant alveolar bone loss, a heightened antibody response, an elevated cytokine immune response, a significant shift in viral diversity and virome composition, and a widening of the PDL space; the latter two findings have not been previously reported in periodontal disease models. Changes in the PDL space were present at sites far away from the site of insult, indicating that the polymicrobial radius of effect extends beyond the bone loss areas and site of initial infection and wider than previously appreciated. Associations were found between bone loss, specific viral and bacterial species, immune genes, and PDL space changes. These findings may have significant implications for the pathogenesis of periodontal disease and biomechanical properties of the periodontium. This new polymicrobial mouse model of periodontal disease in a common mouse strain is useful for evaluating the features of periodontal disease

Content validity and test-retest reliability of patient perception of intensity of urgency scale (PPIUS) for overactive bladder

BACKGROUND: The Patient Perception of Intensity of Urgency Scale (PPIUS) is a patient-reported outcome instrument intended to measure the intensity of urgency associated with each urinary or incontinence episode. The objectives of this study were to assess the content validity, test-retest reliability, and acclimation effect of the PPIUS in overactive bladder (OAB) patients. METHODS: Patients undergoing treatment for OAB were recruited to participate in a non-interventional study by completing a three-day micturition diary including the PPIUS for three consecutive weeks. Following completion of the three-week study, participants from two select sites also completed a cognitive interview to assess their comprehension of the PPIUS. RESULTS: Thirty-nine participants successfully completed the three-week test-retest study; twelve of these participants completed the cognitive interview. Test-retest reliability was high based on intra-class correlation coefficient of 0.95. Among stable patients, the difference between the mean ratings of any two weeks was non-significant. Among the twelve interview participants, nine found it simple to choose a PPIUS rating for each of their micturition episodes and most found the urgency rating definitions consistent with their urgency experiences. CONCLUSIONS: The results demonstrated content validity based on qualitative interviews, and excellent test-retest reliability among stable patients. In addition, no acclimation effect was observed among stable patients. These findings support the use of the PPIUS as a reliable measure of urgency in both clinical trial and real life settings. The validity of PPIUS could be further established with future studies investigating the relationship between discretely graded urgency and incontinence continuum

Dissociation of ssDNA - Single-Walled Carbon Nanotube Hybrids by Watson-Crick Base Pairing

The unwrapping event of ssDNA from the SWNT during the Watson-Crick base paring is investigated through electrical and optical methods, and binding energy calculations. While the ssDNA-metallic SWNT hybrid shows the p-type semiconducting property, the hybridization product recovered metallic properties. The gel electrophoresis directly verifies the result of wrapping and unwrapping events which was also reflected to the Raman shifts. Our molecular dynamics simulations and binding energy calculations provide atomistic description for the pathway to this phenomenon. This nano-physical phenomenon will open up a new approach for nano-bio sensing of specific sequences with the advantages of efficient particle-based recognition, no labeling, and direct electrical detection which can be easily realized into a microfluidic chip format.Comment: 4 pages, 4 figure

Preparation of Nanotube TiO2-Carbon Composite and Its Anode Performance in Lithium-Ion Batteries

A nanocomposite between carbon and nanotube TiO2 (CNTT) was prepared by addition of activated carbon during hydrothermal treatment of TiO2 and following high-temperature calcinations. From morphological analysis using a scanning electron microscope, transmission electron microscope, and N2 sorption profiles, it was revealed that nanotube TiO2 was homogeneously dispersed with carbon in nanoscale for CNTT materials. When applied into the anode in a lithium-ion battery, CNTT electrodes displayed higher cyclability and better rate capability. From ac-impedance measurement, the total resistance was smaller in the CNTT electrode due to a homogeneously dispersed carbon in nanoscale and a more porous structure.This research was supported by a grant from the Fundamental Research and Development Program for Core Technology of Materials funded by the Ministry of Knowledge Economy, Republic of Korea

Microfluidic Hanging-Drop Platforms for 3D Microtissue Culture and Analysis

This thesis presents the concept and applications of microfluidic hanging-drop platforms for the culture and analysis of 3D microtissues – an emerging in vitro cell culture model. The motivation of this work was to bridge the gap between advances in 3D cell cultures and the commonly used cell culture platforms, which are designed prevalently for static and 2D cell cultures, and to demonstrate the potential of dedicated 3D cell culture platforms in providing suitable and reliable experimental conditions. Hanging drops are used for the scaffold-free formation and culture of spherical 3D microtissues. These microtissues are easy to handle and feature many organotypic tissue functions, which renders them a suitable in vitro model system for both, basic research, and pharmaceutical industry. Despite the biological relevance and advantages of these microtissue model systems, the lack of optimized platforms for culturing and analysis still limits the widespread use and application of 3D microtissues in biomedical testing and pharmaceutical compound screening. Microfabrication techniques offer a great toolbox to build next-generation cell culturing and analysis systems. The combination of microfluidics to realize physiologically-relevant culture conditions and microfabricated sensor units enables the realization of integrated systems for organ-, and body-on-a-chip applications. This thesis presents the fabrication, working principle and operation of microfluidic hanging-drop networks for the culturing and analysis of 3D microtissues, and introduces three dedicated platforms for interrogating 3D models. i. Biosensing in hanging-drop networks. Enzyme-based biosensors were integrated in hanging-drop networks for real-time in situ multi-analyte monitoring of 3D microtissue metabolism. The device enabled online detection of lactate secretion and glucose consumption of human colon cancer microtissues. ii. High-resolution imaging in hanging-drop networks. Integration of hydrogels in hanging-drop networks enabled both, immobilization of 3D microtissues for high-resolution and long-term imaging, as well as providing fine control over the microenvironment of the 3D microtissues. The system allows for investigating complex biological processes down to single-cell level and for observation of physiologically events at subcellular scale. iii. FlowGSIS in hanging drops. A hanging-drop perfusion system was developed for studying the dynamics of glucose-stimulated insulin secretion (GSIS) of human endocrine pancreas islets. The device enabled high-temporal-resolution sampling to resolve the bi-phasic and pulsatile insulin release of single islets to study the effects of anti-diabetic medication. The presented platforms represent a set of novel tools for culturing and interrogating 3D microtissues. The design and operation of each platform has been optimized for the respective application, ranging from precise stimulation of microtissues and subsequent metabolite detection, to long-term and high-resolution imaging. The broad range of applications served by these platforms and the platform complementarity greatly improve our capability of taking full advantage of 3D microtissues as organotypic in vitro model systems

An extended global Inventory of Mars Surface Faults

For a quantitative assessment and interpretation of the tectonic history of Mars, a global mapping of tectonic structures is necessary. Based on the fault inventory used previously to model the expected spatial distribution of seismic activity on Mars [1], we have produced a new, more extensive catalog of thrust and normal faults on Mars. We have revised the fault traces contained in the catalog of [1], removing some minor inaccuracies, and added 1409 new thrust faults and 4925 normal faults, with a cumulative length of about 340000 km, which were previously not contained. The total numbers of faults are now 5146 thrust and 9689 normal faults, with a cumulative length of about 941000 km. All faults were mapped based on a global shaded relief map derived from MOLA (Mars Orbiting Laser Altimeter) topography data, with a map resolution of 1 km per pixel. The topographic map was artificially illuminated from two different directions, 90 degrees apart, to avoid any sampling bias by illumination geometry. Additionally, a global 3-D anaglyphic map (Knapmeyer et al., shown elsewhere on this conference) was used to support the identification of faults. The ESRI ArcGIS and the GRASS open-source software were used for mapping, interpolation to uniform sampling and numerical evaluations. A digitized version of the USGS geological map of Mars [2] [3] [4] was manually registered to the MOLA map and absolute surface ages were assigned based on crater statistics. All faults were gathered into several groups and sub-groups of presumably common tectonic origin, and relative ages of these groups and sub-groups were derived from cross-cutting relations between them. These relative ages allow inferring a sequence of tectonic events or epochs independent of the crater statistical ages. References: [1] Knapmeyer M. et al. JGR, 111,E11006, doi:10.1029/2006JE002708,2006. [2] Scott & Tanaka, Map I-1802-A, USGS, 1986 [3] Greeley & Guest, Map I-1802-B, USGS, 1987 [4] Tanaka & Scott, Map I-1802-C, USGS, 198