Indole and 3-indolylacetonitrile inhibit spore maturation in Paenibacillus alvei

<p>Abstract</p> <p>Background</p> <p>Bacteria use diverse signaling molecules to ensure the survival of the species in environmental niches. A variety of both Gram-positive and Gram-negative bacteria produce large quantities of indole that functions as an intercellular signal controlling diverse aspects of bacterial physiology.</p> <p>Results</p> <p>In this study, we sought a novel role of indole in a Gram-positive bacteria <it>Paenibacillus alvei </it>that can produce extracellular indole at a concentration of up to 300 μM in the stationary phase in Luria-Bertani medium. Unlike previous studies, our data show that the production of indole in <it>P. alvei </it>is strictly controlled by catabolite repression since the addition of glucose and glycerol completely turns off the indole production. The addition of exogenous indole markedly inhibits the heat resistance of <it>P. alvei </it>without affecting cell growth. Observation of cell morphology with electron microscopy shows that indole inhibits the development of spore coats and cortex in <it>P. alvei</it>. As a result of the immature spore formation of <it>P. alvei</it>, indole also decreases <it>P. alvei </it>survival when exposed to antibiotics, low pH, and ethanol. Additionally, indole derivatives also influence the heat resistance; for example, a plant auxin, 3-indolylacetonitrile dramatically (2900-fold) decreased the heat resistance of <it>P. alvei</it>, while another auxin 3-indoleacetic acid had a less significant influence on the heat resistance of <it>P. alvei</it>.</p> <p>Conclusions</p> <p>Together, our results demonstrate that indole and plant auxin 3-indolylacetonitrile inhibit spore maturation of <it>P. alvei </it>and that 3-indolylacetonitrile presents an opportunity for the control of heat and antimicrobial resistant spores of Gram-positive bacteria.</p

Fully integrated lab-on-a-disc for simultaneous analysis of biochemistry and immunoassay from whole blood

We report a fully integrated device that can perform both multiple biochemical analysis and sandwich type immunoassay simultaneously on a disc. The whole blood is applied directly to the disposable &quot;lab-on-a-disc&quot; containing different kinds of freeze-dried reagents for the blood chemistry analysis as well as reagents required for the immunoassay. The concentrations of different kinds of analytes are reported within 22 min by simply inserting a disc to a portable device. Using the innovative laser irradiated ferrowax microvalves together with the centrifugal microfluidics, the total process of plasma separation, metering, mixing, incubation, washing, and detection is fully automated. The analyzer is equipped with an optical detection module to measure absorbances at 10 different wavelengths to accommodate the various kinds of reaction protocols. Compared to the conventional blood analysis done in clinical laboratories, it is advantageous for point-of-care applications because it requires a smaller amount of blood (350 mu L vs. 3 mL), takes less time (22 min vs. several days), does not require specially trained operators or expensive instruments to run biochemical analysis and immunoassay separately.close554

Electrochemical velocimetry on centrifugal microfluidic platforms

Expanding upon recent applications of interfacing electricity with centrifugal microfluidic platforms, we introduce electrochemical velocimetry to monitor flow in real-time on rotating fluidic devices. Monitoring flow by electrochemical techniques requires a simple, compact setup of miniaturized electrodes that are embedded within a microfluidic channel and are connected to a peripherally-located potentiostat. On-disc flow rates, determined by electrochemical velocimetry, agreed well with theoretically expected values and with optical measurements. As an application of the presented techniques, the dynamic process of droplet formation and release was recorded, yielding critical information about droplet frequency and volume. Overall, the techniques presented in this work advance the field of centrifugal microfluidics by offering a powerful tool, previously unavailable, to monitor flow in real-time on rotating microfluidic systems.close4

DC Networks on the Distribution Level – New Trend or Vision?

"DC networks on Distribution Level – are they a new trend or a Vision?" That is the question that has focused the efforts of the Working Group the last two years, and whose consideration is summarized in this report. This report represents the first phase evaluation of this topic and is focused primarily on medium (MVDC) and low voltage (LVDC) level applications

High-Efficiency Bi-Directional Single-Phase AC/DC Converter Design and Field Application for LVDC Distribution

This paper describes the design and field application of a high-efficiency single-phase AC/DC converter that is suitable for distribution lines. First, an appropriate AC/DC converter was designed in consideration of the environment of the application system. In order to ensure high efficiency and high reliability, we designed an optimum switching element and capacitor suitable for the converter, and the protection element of the AC/DC converter was designed based on these elements. The control function for the power converter suitable for an LVDC distribution system is proposed for highly reliable operation. The AC/DC converter was manufactured based on the design and its performance was verified during application in an actual low-voltage DC (LVDC) distribution grid through tests at the demonstration site. The application to a DC distribution system in an actual grid is very rare and it is expected that it will contribute to the expansion of LVDC distribution

Application of a DC Distribution System in Korea: A Case Study of the LVDC Project

With the rapid expansion of renewable energy and digital devices, there is a need for direct current (DC) distribution technology that can increase energy efficiency. As a result, DC distribution research is actively underway to cope with the sudden digitization and decentralization of load environment and power supply. To verify the possibility of DC distribution, Korea Electric Power Corporation (KEPCO) Research Institute made a DC distribution system connected with a real power system in Gwangju. The construction of the demonstration area mainly includes design of protection and grounding systems, operating procedures of insulation monitoring device (IMD), and construction of power converters. Furthermore, this paper goes beyond the simulation and the lab testing to apply DC distribution to a real system operation in advance. It is designed as a long-distance low-loaded customer for rural areas and operated by the DC distribution. In addition, safety and reliability are confirmed through field tests of DC distribution elements such as power conversion devices, protection and grounding systems. In particular, to improve the reliability of non-grounding system, the insulation monitoring device was installed and the algorithms of its operational procedures are proposed. Finally, this paper analyzes the problems caused by operating the actual DC distribution and suggests solutions accordingly

Does CSR Assurance Affect the Relationship between CSR Performance and Financial Performance?

In this study, we investigate the effect of assurance service of corporate social responsibility (CSR) reports on the relationship between CSR performance and firms&rsquo; financial performance. Specifically, we question whether firms having their CSR performance assured to benefit from such assurance services. Theory suggests that investors apply a lower discount rate when valuing firms if information from the firms is credible. Using a sample of 5040 large U.S. companies, we find that the CSR performance is positively associated with the firms&rsquo; financial performance on average and that there is a significant effect of CSR assurance service on the relationship between CSR performance and firms&rsquo; financial performance. This implies that firms having their CSR reports assured by external experts experience much higher financial performance than firms without such assurance service. Our findings are consistent with the prior studies and support our argument with regard to the CSR assurance service. The findings have implications for firms considering CSR assurance and accounting professionals for their opportunities

Cloud Cover Forecast Based on Correlation Analysis on Satellite Images for Short-Term Photovoltaic Power Forecasting

Photovoltaic power generation must be predicted to counter the system instability caused by an increasing number of photovoltaic power-plant connections. In this study, a method for predicting the cloud volume and power generation using satellite images is proposed. Generally, solar irradiance and cloud cover have a high correlation. However, because the predicted solar irradiance is not provided by the Meteorological Administration or a weather site, cloud cover can be used instead of the predicted solar radiation. A lot of information, such as the direction and speed of movement of the cloud is contained in the satellite image. Therefore, the spatio-temporal correlation of the cloud is obtained from satellite images, and this correlation is presented pictorially. When the learning is complete, the current satellite image can be entered at the current time and the cloud value for the desired time can be obtained. In the case of the predictive model, the artificial neural network (ANN) model with the identical hyperparameters or setting values is used for data performance evaluation. Four cases of forecasting models are tested: cloud cover, visible image, infrared image, and a combination of the three variables. According to the result, the multivariable case showed the best performance for all test periods. Among single variable models, cloud cover presented a fair performance for short-term forecasting, and visible image presented a good performance for ultra-short-term forecasting

Probabilistic Stability Evaluation Based on Confidence Interval in Distribution Systems with Inverter-Based Distributed Generations

This study proposed a probabilistic methodology based on a confidence interval with the aim of overcoming the limitations of deterministic methods. A stability evaluation technique was required because the output variability of renewable energy can lead to instability of the distribution system. The proposed method can predict the possibility of violating stability in the future. It can also provide a theoretical basis for securing distribution system stability and improving operational efficiency by assessing the in-stability risk and worst-case scenarios. Because of steady-state analysis in the distribution system to which solar power is connected, the probability of violating the standard voltage during the daytime when PV fluctuations are severe was the highest. Moreover, as a result of a simulation of a three-phase short-circuit in the distribution system that is connected to the PV and WT, it was observed that it could violate the allowable capacity of the CB owing to the effects of the power demand pattern and output variability