Network Capacity Assessment of CHP-based Distributed Generation on Urban Energy Distribution Networks

NASA Astrophysics Data System (ADS)

Zhang, Xianjun

The combined heat and power (CHP)-based distributed generation (DG) or dis-tributed energy resources (DERs) are mature options available in the present energy market, considered to be an effective solution to promote energy efficiency. In the urban environment, the electricity, water and natural gas distribution networks are becoming increasingly interconnected with the growing penetration of the CHP-based DG. Subsequently, this emerging interdependence leads to new topics meriting serious consideration: how much of the CHP-based DG can be accommodated and where to locate these DERs, and given preexisting constraints, how to quantify the mutual impacts on operation performances between these urban energy distribution networks and the CHP-based DG. The early research work was conducted to investigate the feasibility and design methods for one residential microgrid system based on existing electricity, water and gas infrastructures of a residential community, mainly focusing on the economic planning. However, this proposed design method cannot determine the optimal DG sizing and siting for a larger test bed with the given information of energy infrastructures. In this context, a more systematic as well as generalized approach should be developed to solve these problems. In the later study, the model architecture that integrates urban electricity, water and gas distribution networks, and the CHP-based DG system was developed. The proposed approach addressed the challenge of identifying the optimal sizing and siting of the CHP-based DG on these urban energy networks and the mutual impacts on operation performances were also quantified. For this study, the overall objective is to maximize the electrical output and recovered thermal output of the CHP-based DG units. The electricity, gas, and water system models were developed individually and coupled by the developed CHP-based DG system model. The resultant integrated system model is used to constrain the DG's electrical output and recovered thermal output, which are affected by multiple factors and thus analyzed in different case studies. The results indicate that the designed typical gas system is capable of supplying sufficient natural gas for the DG normal operation, while the present water system cannot support the complete recovery of the exhaust heat from the DG units.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bluestein, J.; Horgan, S.; Eldridge, M. M.

Relatively small projects for generating electrical power at or near the point of use--distributed generation (DG)--offer unique opportunities for enhancing the U.S. electric system. This report finds that current air quality regulatory practices are inappropriately inhibiting the development of DG through a failure to recognize the environmental benefits offered by DG or by imposing requirements designed for larger systems that are not appropriate to DG systems. The report recommends that air quality regulation be made more efficient and appropriate for DG by establishing national standards for DG equipment. This report also recommends that DG projects be evaluated on a''net'' emissionsmore » basis by being given credit for any emission sources that they displace. Air quality regulation should also recognize the benefits of combined heat and power (CHP).« less

Anti-islanding Protection of Distributed Generation Using Rate of Change of Impedance

NASA Astrophysics Data System (ADS)

Shah, Pragnesh; Bhalja, Bhavesh

2013-08-01

Distributed Generation (DG), which is interlinked with distribution system, has inevitable effect on distribution system. Integrating DG with the utility network demands an anti-islanding scheme to protect the system. Failure to trip islanded generators can lead to problems such as threats to personnel safety, out-of-phase reclosing, and degradation of power quality. In this article, a new method for anti-islanding protection based on impedance monitoring of distribution network is carried out in presence of DG. The impedance measured between two phases is used to derive the rate of change of impedance (dz/dt), and its peak values are used for final trip decision. Test data are generated using PSCAD/EMTDC software package and the performance of the proposed method is evaluated in MatLab software. The simulation results show the effectiveness of the proposed scheme as it is capable to detect islanding condition accurately. Subsequently, it is also observed that the proposed scheme does not mal-operate during other disturbances such as short circuit and switching event.

Informing Mexico's Distributed Generation Policy with System Advisor Model (SAM) Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aznar, Alexandra Y; Zinaman, Owen R; McCall, James D

The Government of Mexico recognizes the potential for clean distributed generation (DG) to meaningfully contribute to Mexico's clean energy and emissions reduction goals. However, important questions remain about how to fairly value DG and foster inclusive and equitable market growth that is beneficial to investors, electricity ratepayers, electricity distributors, and society. The U.S. National Renewable Energy Laboratory (NREL) has partnered with power sector institutions and stakeholders in Mexico to provide timely analytical support and expertise to help inform policymaking processes on clean DG. This document describes two technical assistance interventions that used the System Advisor Model (SAM) to inform Mexico'smore » DG policymaking processes with a focus on rooftop solar regulation and policy.« less

Design optimization of a fuzzy distributed generation (DG) system with multiple renewable energy sources

NASA Astrophysics Data System (ADS)

Ganesan, T.; Elamvazuthi, I.; Shaari, Ku Zilati Ku; Vasant, P.

2012-09-01

The global rise in energy demands brings major obstacles to many energy organizations in providing adequate energy supply. Hence, many techniques to generate cost effective, reliable and environmentally friendly alternative energy source are being explored. One such method is the integration of photovoltaic cells, wind turbine generators and fuel-based generators, included with storage batteries. This sort of power systems are known as distributed generation (DG) power system. However, the application of DG power systems raise certain issues such as cost effectiveness, environmental impact and reliability. The modelling as well as the optimization of this DG power system was successfully performed in the previous work using Particle Swarm Optimization (PSO). The central idea of that work was to minimize cost, minimize emissions and maximize reliability (multi-objective (MO) setting) with respect to the power balance and design requirements. In this work, we introduce a fuzzy model that takes into account the uncertain nature of certain variables in the DG system which are dependent on the weather conditions (such as; the insolation and wind speed profiles). The MO optimization in a fuzzy environment was performed by applying the Hopfield Recurrent Neural Network (HNN). Analysis on the optimized results was then carried out.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Linvill, Carl; Brutkoski, Donna

Mexico's energy reform will have far-reaching effects on how people produce and consume electricity in the country. Market liberalization will open the door to an increasing number of options for Mexican residential, commercial, and industrial consumers, and distributed generation (DG), which for Mexico includes generators of less than 500 kilowatts (kW) of capacity connected to the distribution network. Distributed generation is an option for consumers who want to produce their own electricity and provide electricity services to others. This report seeks to provide guidance to Mexican officials on designing DG economic and regulatory policies.

Stochastic DG Placement for Conservation Voltage Reduction Based on Multiple Replications Procedure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhaoyu; Chen, Bokan; Wang, Jianhui

2015-06-01

Conservation voltage reduction (CVR) and distributed-generation (DG) integration are popular strategies implemented by utilities to improve energy efficiency. This paper investigates the interactions between CVR and DG placement to minimize load consumption in distribution networks, while keeping the lowest voltage level within the predefined range. The optimal placement of DG units is formulated as a stochastic optimization problem considering the uncertainty of DG outputs and load consumptions. A sample average approximation algorithm-based technique is developed to solve the formulated problem effectively. A multiple replications procedure is developed to test the stability of the solution and calculate the confidence interval ofmore » the gap between the candidate solution and optimal solution. The proposed method has been applied to the IEEE 37-bus distribution test system with different scenarios. The numerical results indicate that the implementations of CVR and DG, if combined, can achieve significant energy savings.« less

Probabilistic Harmonic Analysis on Distributed Photovoltaic Integration Considering Typical Weather Scenarios

NASA Astrophysics Data System (ADS)

Bin, Che; Ruoying, Yu; Dongsheng, Dang; Xiangyan, Wang

2017-05-01

Distributed Generation (DG) integrating to the network would cause the harmonic pollution which would cause damages on electrical devices and affect the normal operation of power system. On the other hand, due to the randomness of the wind and solar irradiation, the output of DG is random, too, which leads to an uncertainty of the harmonic generated by the DG. Thus, probabilistic methods are needed to analyse the impacts of the DG integration. In this work we studied the harmonic voltage probabilistic distribution and the harmonic distortion in distributed network after the distributed photovoltaic (DPV) system integrating in different weather conditions, mainly the sunny day, cloudy day, rainy day and the snowy day. The probabilistic distribution function of the DPV output power in different typical weather conditions could be acquired via the parameter identification method of maximum likelihood estimation. The Monte-Carlo simulation method was adopted to calculate the probabilistic distribution of harmonic voltage content at different frequency orders as well as the harmonic distortion (THD) in typical weather conditions. The case study was based on the IEEE33 system and the results of harmonic voltage content probabilistic distribution as well as THD in typical weather conditions were compared.

Grid-Connected Distributed Generation: Compensation Mechanism Basics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aznar, Alexandra Y; Zinaman, Owen R

2017-10-02

This short report defines compensation mechanisms for grid-connected, behind-the-meter distributed generation (DG) systems as instruments that comprise three core elements: (1) metering and billing arrangements, (2) sell rate design, and (3) retail rate design. This report describes metering and billing arrangements, with some limited discussion of sell rate design. We detail the three possible arrangements for metering and billing of DG: net energy metering (NEM); buy all, sell all; and net billing.

Adoption and supply of a distributed energy technology

NASA Astrophysics Data System (ADS)

Strachan, Neil Douglas

2000-12-01

Technical and economic developments in distributed generation (DG) represent an opportunity for a radically different energy market paradigm, and potentially significant cuts in global carbon emissions. This thesis investigates DG along two interrelated themes: (1) Early adoption and supply of the DG technology of internal combustion (IC) engine cogeneration. (2) Private and social cost implications of DG for private investors and within an energy system. IC engine cogeneration of both power and heat has been a remarkable success in the Netherlands with over 5,000 installations and 1,500MWe of installed capacity by 1997. However, the technology has struggled in the UK with an installed capacity of 110Mwe, fulfilling only 10% of its large estimated potential. An investment simulation model of DG investments in the UK and Netherlands was used, together with analysis of site level data on all DG adoptions from 1985 through 1997. In the UK over 60% of the early installations were sized too small (<140kWe) to be economically attractive (suppliers made their money with maintenance contracts). In the Netherlands, most facilities were sized well above the economic size threshold of 100kWe (lower due to reduced operating and grid connection costs). Institutional players were key in improved sizing of DG. Aided by energy market and CO2 reduction regulatory policy, Dutch distributions utilities played a proactive role in DG. This involved joint ventures with engine cogen suppliers and users, offering improved electricity buy-back tariffs and lower connection costs. This has allowed flexible operation of distributed generation, especially in electricity sales to the grid. Larger units can be sized for on-site heat requirements with electricity export providing revenue and aiding in management of energy networks. A comparison of internal and external costs of three distributed and three centralized generation technologies over a range of heat to power ratios (HPR) was made. Micro-turbines were found to be the lowest cost technology, especially at higher heat loads. Engines are also very competitive providing their NOx and CO emissions are controlled. A cost optimization program was used to develop an optimal green-field supply mix for Florida and New York. (Abstract shortened by UMI.)

Air quality impacts of distributed power generation in the South Coast Air Basin of California 1: Scenario development and modeling analysis

NASA Astrophysics Data System (ADS)

Rodriguez, M. A.; Carreras-Sospedra, M.; Medrano, M.; Brouwer, J.; Samuelsen, G. S.; Dabdub, D.

Distributed generation (DG) is generally defined as the operation of many small stationary power generators throughout an urban air basin. Although DG has the potential to supply a significant portion of the increased power demands in California and the rest of the United States, it may lead to increased levels of in-basin pollutants and adversely impact urban air quality. This study focuses on two main objectives: (1) the systematic characterization of DG installation in urban air basins, and (2) the simulation of potential air quality impacts using a state-of-the-art three-dimensional computational model. A general and systematic approach is devised to construct five realistic and 21 spanning scenarios of DG implementation in the South Coast Air Basin (SoCAB) of California. Realistic scenarios reflect an anticipated level of DG deployment in the SoCAB by the year 2010. Spanning scenarios are developed to determine the potential impacts of unexpected outcomes. Realistic implementations of DG in the SoCAB result in small differences in ozone and particulate matter concentrations in the basin compared to the baseline simulations. The baseline accounts for population increase, but does not consider any future emissions control measures. Model results for spanning implementations with extra high DG market penetration show that domain-wide ozone peak concentrations increase significantly. Also, air quality impacts of spanning implementations when DG operate during a 6-h period are larger than when the same amount of emissions are introduced during a 24-h period.

An adequacy-constrained integrated planning method for effective accommodation of DG and electric vehicles in smart distribution systems

NASA Astrophysics Data System (ADS)

Tan, Zhukui; Xie, Baiming; Zhao, Yuanliang; Dou, Jinyue; Yan, Tong; Liu, Bin; Zeng, Ming

2018-06-01

This paper presents a new integrated planning framework for effective accommodating electric vehicles in smart distribution systems (SDS). The proposed method incorporates various investment options available for the utility collectively, including distributed generation (DG), capacitors and network reinforcement. Using a back-propagation algorithm combined with cost-benefit analysis, the optimal network upgrade plan, allocation and sizing of the selected components are determined, with the purpose of minimizing the total system capital and operating costs of DG and EV accommodation. Furthermore, a new iterative reliability test method is proposed. It can check the optimization results by subsequently simulating the reliability level of the planning scheme, and modify the generation reserve margin to guarantee acceptable adequacy levels for each year of the planning horizon. Numerical results based on a 32-bus distribution system verify the effectiveness of the proposed method.

Application Processing | Distributed Generation Interconnection

Science.gov Websites

delivering swift customer service. The rapid rise of distributed generation (DG) PV interconnection speed processing, reduce paperwork, and improve customer service. Webinars and publications are

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siddiqui, Afzal; Marnay, Chris

This paper examines a California-based microgrid s decision to invest in a distributed generation (DG) unit that operates on natural gas. While the long-term natural gas generation cost is stochastic, we initially assume that the microgrid may purchase electricity at a fixed retail rate from its utility. Using the real options approach, we find natural gas generating cost thresholds that trigger DG investment. Furthermore, the consideration of operational flexibility by the microgrid accelerates DG investment, while the option to disconnect entirely from the utility is not attractive. By allowing the electricity price to be stochastic, we next determine an investmentmore » threshold boundary and find that high electricity price volatility relative to that of natural gas generating cost delays investment while simultaneously increasing the value of the investment. We conclude by using this result to find the implicit option value of the DG unit.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marnay, Chris; Siddiqui, Afzal; Marnay, Chris

This paper examines a California-based microgrid?s decision to invest in a distributed generation (DG) unit fuelled by natural gas. While the long-term natural gas generation cost is stochastic, we initially assume that the microgrid may purchase electricity at a fixed retail rate from its utility. Using the real options approach, we find a natural gas generation cost threshold that triggers DG investment. Furthermore, the consideration of operational flexibility by the microgrid increases DG investment, while the option to disconnect from the utility is not attractive. By allowing the electricity price to be stochastic, we next determine an investment threshold boundarymore » and find that high electricity price volatility relative to that of natural gas generation cost delays investment while simultaneously increasing the value of the investment. We conclude by using this result to find the implicit option value of the DG unit when two sources of uncertainty exist.« less

Mitigation of Power Quality Problems in Grid-Interactive Distributed Generation System

NASA Astrophysics Data System (ADS)

Bhende, C. N.; Kalam, A.; Malla, S. G.

2016-04-01

Having an inter-tie between low/medium voltage grid and distributed generation (DG), both exposes to power quality (PQ) problems created by each other. This paper addresses various PQ problems arise due to integration of DG with grid. The major PQ problems are due to unbalanced and non-linear load connected at DG, unbalanced voltage variations on transmission line and unbalanced grid voltages which severely affect the performance of the system. To mitigate the above mentioned PQ problems, a novel integrated control of distribution static shunt compensator (DSTATCOM) is presented in this paper. DSTATCOM control helps in reducing the unbalance factor of PCC voltage. It also eliminates harmonics from line currents and makes them balanced. Moreover, DSTATCOM supplies the reactive power required by the load locally and hence, grid need not to supply the reactive power. To show the efficacy of the proposed controller, several operating conditions are considered and verified through simulation using MATLAB/SIMULINK.

Islanding detection and over voltage mitigation using wireless sensor networks and electric vehicle charging stations.

DOT National Transportation Integrated Search

2016-06-01

An islanding condition occurs when a distributed generation (DG) unit continues to energize a : part of the grid while said part has been isolated from the main electrical utility. In this event, if : the power of the DG exceeds the load, a transient...

Intake-to-delivered-energy ratios for central station and distributed electricity generation in California

NASA Astrophysics Data System (ADS)

Heath, Garvin A.; Nazaroff, William W.

In previous work, we showed that the intake fraction (iF) for nonreactive primary air pollutants was 20 times higher in central tendency for small-scale, urban-sited distributed electricity generation (DG) sources than for large-scale, central station (CS) power plants in California [Heath, G.A., Granvold, P.W., Hoats, A.S., Nazaroff, W.W., 2006. Intake fraction assessment of the air pollutant exposure implications of a shift toward distributed electricity generation. Atmospheric Environment 40, 7164-7177]. The present paper builds on that study, exploring pollutant- and technology-specific aspects of population inhalation exposure from electricity generation. We compare California's existing CS-based system to one that is more reliant on DG units sited in urban areas. We use Gaussian plume modeling and a GIS-based exposure analysis to assess 25 existing CSs and 11 DG sources hypothetically located in the downtowns of California's most populous cities. We consider population intake of three pollutants—PM 2.5, NO x and formaldehyde—directly emitted by five DG technologies—natural gas (NG)-fired turbines, NG internal combustion engines (ICE), NG microturbines, diesel ICEs, and fuel cells with on-site NG reformers. We also consider intake of these pollutants from existing CS facilities, most of which use large NG turbines, as well as from hypothetical facilities located at these same sites but meeting California's best-available control technology standards. After systematically exploring the sensitivity of iF to pollutant decay rate, the iFs for each of the three pollutants for all DG and CS cases are estimated. To efficiently compare the pollutant- and technology-specific exposure potential on an appropriate common basis, a new metric is introduced and evaluated: the intake-to-delivered-energy ratio (IDER). The IDER expresses the mass of pollutant inhaled by an exposed population owing to emissions from an electricity generation unit per quantity of electric energy delivered to the place of use. We find that the central tendency of IDER is much greater for almost every DG technology evaluated than for existing CS facilities in California.

Distributed cooperative control of AC microgrids

NASA Astrophysics Data System (ADS)

Bidram, Ali

In this dissertation, the comprehensive secondary control of electric power microgrids is of concern. Microgrid technical challenges are mainly realized through the hierarchical control structure, including primary, secondary, and tertiary control levels. Primary control level is locally implemented at each distributed generator (DG), while the secondary and tertiary control levels are conventionally implemented through a centralized control structure. The centralized structure requires a central controller which increases the reliability concerns by posing the single point of failure. In this dissertation, the distributed control structure using the distributed cooperative control of multi-agent systems is exploited to increase the secondary control reliability. The secondary control objectives are microgrid voltage and frequency, and distributed generators (DGs) active and reactive powers. Fully distributed control protocols are implemented through distributed communication networks. In the distributed control structure, each DG only requires its own information and the information of its neighbors on the communication network. The distributed structure obviates the requirements for a central controller and complex communication network which, in turn, improves the system reliability. Since the DG dynamics are nonlinear and non-identical, input-output feedback linearization is used to transform the nonlinear dynamics of DGs to linear dynamics. Proposed control frameworks cover the control of microgrids containing inverter-based DGs. Typical microgrid test systems are used to verify the effectiveness of the proposed control protocols.

Reactive power and voltage control strategy based on dynamic and adaptive segment for DG inverter

NASA Astrophysics Data System (ADS)

Zhai, Jianwei; Lin, Xiaoming; Zhang, Yongjun

2018-03-01

The inverter of distributed generation (DG) can support reactive power to help solve the problem of out-of-limit voltage in active distribution network (ADN). Therefore, a reactive voltage control strategy based on dynamic and adaptive segment for DG inverter is put forward to actively control voltage in this paper. The proposed strategy adjusts the segmented voltage threshold of Q(U) droop curve dynamically and adaptively according to the voltage of grid-connected point and the power direction of adjacent downstream line. And then the reactive power reference of DG inverter can be got through modified Q(U) control strategy. The reactive power of inverter is controlled to trace the reference value. The proposed control strategy can not only control the local voltage of grid-connected point but also help to maintain voltage within qualified range considering the terminal voltage of distribution feeder and the reactive support for adjacent downstream DG. The scheme using the proposed strategy is compared with the scheme without the reactive support of DG inverter and the scheme using the Q(U) control strategy with constant segmented voltage threshold. The simulation results suggest that the proposed method has a significant improvement on solving the problem of out-of-limit voltage, restraining voltage variation and improving voltage quality.

The Role of Distributed Generation and Combined Heat and Power (CHP) Systems in Data Centers

EPA Pesticide Factsheets

This report reviews how distributed generation (DG) resources such as fuel cells, reciprocating engines, and gas turbines can offer powerful energy efficiency savings in data centers, particularly when configured in combined heat and power (CHP) mode.

Advanced Energy Storage Management in Distribution Network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Guodong; Ceylan, Oguzhan; Xiao, Bailu

2016-01-01

With increasing penetration of distributed generation (DG) in the distribution networks (DN), the secure and optimal operation of DN has become an important concern. In this paper, an iterative mixed integer quadratic constrained quadratic programming model to optimize the operation of a three phase unbalanced distribution system with high penetration of Photovoltaic (PV) panels, DG and energy storage (ES) is developed. The proposed model minimizes not only the operating cost, including fuel cost and purchasing cost, but also voltage deviations and power loss. The optimization model is based on the linearized sensitivity coefficients between state variables (e.g., node voltages) andmore » control variables (e.g., real and reactive power injections of DG and ES). To avoid slow convergence when close to the optimum, a golden search method is introduced to control the step size and accelerate the convergence. The proposed algorithm is demonstrated on modified IEEE 13 nodes test feeders with multiple PV panels, DG and ES. Numerical simulation results validate the proposed algorithm. Various scenarios of system configuration are studied and some critical findings are concluded.« less

Distributed Generation Planning using Peer Enhanced Multi-objective Teaching-Learning based Optimization in Distribution Networks

NASA Astrophysics Data System (ADS)

Selvam, Kayalvizhi; Vinod Kumar, D. M.; Siripuram, Ramakanth

2017-04-01

In this paper, an optimization technique called peer enhanced teaching learning based optimization (PeTLBO) algorithm is used in multi-objective problem domain. The PeTLBO algorithm is parameter less so it reduced the computational burden. The proposed peer enhanced multi-objective based TLBO (PeMOTLBO) algorithm has been utilized to find a set of non-dominated optimal solutions [distributed generation (DG) location and sizing in distribution network]. The objectives considered are: real power loss and the voltage deviation subjected to voltage limits and maximum penetration level of DG in distribution network. Since the DG considered is capable of injecting real and reactive power to the distribution network the power factor is considered as 0.85 lead. The proposed peer enhanced multi-objective optimization technique provides different trade-off solutions in order to find the best compromise solution a fuzzy set theory approach has been used. The effectiveness of this proposed PeMOTLBO is tested on IEEE 33-bus and Indian 85-bus distribution system. The performance is validated with Pareto fronts and two performance metrics (C-metric and S-metric) by comparing with robust multi-objective technique called non-dominated sorting genetic algorithm-II and also with the basic TLBO.

Modeling and Optimization of Commercial Buildings and Stationary Fuel Cell Systems (Presentation)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ainscough, C.; McLarty, D.; Sullivan, R.

2013-10-01

This presentation describes the Distributed Generation Building Energy Assessment Tool (DG-BEAT) developed by the National Renewable Energy Laboratory and the University of California Irvine. DG-BEAT is designed to allow stakeholders to assess the economics of installing stationary fuel cell systems in a variety of building types in the United States.

Path Searching Based Fault Automated Recovery Scheme for Distribution Grid with DG

NASA Astrophysics Data System (ADS)

Xia, Lin; Qun, Wang; Hui, Xue; Simeng, Zhu

2016-12-01

Applying the method of path searching based on distribution network topology in setting software has a good effect, and the path searching method containing DG power source is also applicable to the automatic generation and division of planned islands after the fault. This paper applies path searching algorithm in the automatic division of planned islands after faults: starting from the switch of fault isolation, ending in each power source, and according to the line load that the searching path traverses and the load integrated by important optimized searching path, forming optimized division scheme of planned islands that uses each DG as power source and is balanced to local important load. Finally, COBASE software and distribution network automation software applied are used to illustrate the effectiveness of the realization of such automatic restoration program.

Why do electricity policy and competitive markets fail to use advanced PV systems to improve distribution power quality?

DOE Office of Scientific and Technical Information (OSTI.GOV)

McHenry, Mark P.; Johnson, Jay; Hightower, Mike

The increasing pressure for network operators to meet distribution network power quality standards with increasing peak loads, renewable energy targets, and advances in automated distributed power electronics and communications is forcing policy-makers to understand new means to distribute costs and benefits within electricity markets. Discussions surrounding how distributed generation (DG) exhibits active voltage regulation and power factor/reactive power control and other power quality capabilities are complicated by uncertainties of baseline local distribution network power quality and to whom and how costs and benefits of improved electricity infrastructure will be allocated. DG providing ancillary services that dynamically respond to the networkmore » characteristics could lead to major network improvements. With proper market structures renewable energy systems could greatly improve power quality on distribution systems with nearly no additional cost to the grid operators. Renewable DG does have variability challenges, though this issue can be overcome with energy storage, forecasting, and advanced inverter functionality. This paper presents real data from a large-scale grid-connected PV array with large-scale storage and explores effective mitigation measures for PV system variability. As a result, we discuss useful inverter technical knowledge for policy-makers to mitigate ongoing inflation of electricity network tariff components by new DG interconnection requirements or electricity markets which value power quality and control.« less

Why do electricity policy and competitive markets fail to use advanced PV systems to improve distribution power quality?

DOE PAGES

McHenry, Mark P.; Johnson, Jay; Hightower, Mike

2016-01-01

The increasing pressure for network operators to meet distribution network power quality standards with increasing peak loads, renewable energy targets, and advances in automated distributed power electronics and communications is forcing policy-makers to understand new means to distribute costs and benefits within electricity markets. Discussions surrounding how distributed generation (DG) exhibits active voltage regulation and power factor/reactive power control and other power quality capabilities are complicated by uncertainties of baseline local distribution network power quality and to whom and how costs and benefits of improved electricity infrastructure will be allocated. DG providing ancillary services that dynamically respond to the networkmore » characteristics could lead to major network improvements. With proper market structures renewable energy systems could greatly improve power quality on distribution systems with nearly no additional cost to the grid operators. Renewable DG does have variability challenges, though this issue can be overcome with energy storage, forecasting, and advanced inverter functionality. This paper presents real data from a large-scale grid-connected PV array with large-scale storage and explores effective mitigation measures for PV system variability. As a result, we discuss useful inverter technical knowledge for policy-makers to mitigate ongoing inflation of electricity network tariff components by new DG interconnection requirements or electricity markets which value power quality and control.« less

Compensation for Distributed Solar. A Survey of Options to Preserve Stakeholder Value

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flores-Espino, Francisco

2015-09-01

Compensation mechanisms for electricity generation systems installed behind the meter are under scrutiny in several jurisdictions in the United States. Legislators in 29 states introduced bills to amend net metering provisions in 2014, and in 33 states in the 2015 legislative session as of August 20, 2015. Some utilities have also sought to increase the revenue they receive from net-metered customers through rate redesign. The circumstances that have triggered the recent push for change include a growing percentage of net-metered customers, potential effects of distributed generation on cost allocation, decreasing photovoltaic (PV) system costs, the challenges of integrating high levelsmore » of solar generation in the distribution network, and increasing pressure on utility business models. This report presents a survey of options to charge and compensate PV customers, as well as options that may preserve utility revenues in scenarios with increased DG. These options could be used as building blocks to create a distributed generation (DG) compensation policy that may preserve the value of the different stakeholders and balance their interests.« less

Distributed Economic Dispatch in Microgrids Based on Cooperative Reinforcement Learning.

PubMed

Liu, Weirong; Zhuang, Peng; Liang, Hao; Peng, Jun; Huang, Zhiwu; Weirong Liu; Peng Zhuang; Hao Liang; Jun Peng; Zhiwu Huang; Liu, Weirong; Liang, Hao; Peng, Jun; Zhuang, Peng; Huang, Zhiwu

2018-06-01

Microgrids incorporated with distributed generation (DG) units and energy storage (ES) devices are expected to play more and more important roles in the future power systems. Yet, achieving efficient distributed economic dispatch in microgrids is a challenging issue due to the randomness and nonlinear characteristics of DG units and loads. This paper proposes a cooperative reinforcement learning algorithm for distributed economic dispatch in microgrids. Utilizing the learning algorithm can avoid the difficulty of stochastic modeling and high computational complexity. In the cooperative reinforcement learning algorithm, the function approximation is leveraged to deal with the large and continuous state spaces. And a diffusion strategy is incorporated to coordinate the actions of DG units and ES devices. Based on the proposed algorithm, each node in microgrids only needs to communicate with its local neighbors, without relying on any centralized controllers. Algorithm convergence is analyzed, and simulations based on real-world meteorological and load data are conducted to validate the performance of the proposed algorithm.

New method for generating breast models featuring glandular tissue spatial distribution

NASA Astrophysics Data System (ADS)

Paixão, L.; Oliveira, B. B.; Oliveira, M. A.; Teixeira, M. H. A.; Fonseca, T. C. F.; Nogueira, M. S.

2016-02-01

Mammography is the main radiographic technique used for breast imaging. A major concern with mammographic imaging is the risk of radiation-induced breast cancer due to the high sensitivity of breast tissue. The mean glandular dose (DG) is the dosimetric quantity widely accepted to characterize the risk of radiation induced cancer. Previous studies have concluded that DG depends not only on the breast glandular content but also on the spatial distribution of glandular tissue within the breast. In this work, a new method for generating computational breast models featuring skin composition and glandular tissue distribution from patients undergoing digital mammography is proposed. Such models allow a more accurate way of calculating individualized breast glandular doses taking into consideration the glandular tissue fraction. Sixteen breast models of four patients with different glandularity breasts were simulated and the results were compared with those obtained from recommended DG conversion factors. The results show that the internationally recommended conversion factors may be overestimating the mean glandular dose to less dense breasts and underestimating the mean glandular dose for denser breasts. The methodology described in this work constitutes a powerful tool for breast dosimetry, especially for risk studies.

Energy Systems Integration News - September 2016 | Energy Systems

Science.gov Websites

, Smarter Grid Solutions demonstrated a new distributed energy resources (DER) software control platform utility interconnections require distributed generation (DG) devices to disconnect from the grid during OpenFMB distributed applications on the microgrid test site to locally optimize renewable energy resources

NREL Smart Grid Projects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hambrick, J.

2012-01-01

Although implementing Smart Grid projects at the distribution level provides many advantages and opportunities for advanced operation and control, a number of significant challenges must be overcome to maintain the high level of safety and reliability that the modern grid must provide. For example, while distributed generation (DG) promises to provide opportunities to increase reliability and efficiency and may provide grid support services such as volt/var control, the presence of DG can impact distribution operation and protection schemes. Additionally, the intermittent nature of many DG energy sources such as photovoltaics (PV) can present a number of challenges to voltage regulation,more » etc. This presentation provides an overview a number of Smart Grid projects being performed by the National Renewable Energy Laboratory (NREL) along with utility, industry, and academic partners. These projects include modeling and analysis of high penetration PV scenarios (with and without energy storage), development and testing of interconnection and microgrid equipment, as well as the development and implementation of advanced instrumentation and data acquisition used to analyze the impacts of intermittent renewable resources. Additionally, standards development associated with DG interconnection and analysis as well as Smart Grid interoperability will be discussed.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, N.; Ye, Z.

This report documents part of a multiyear research program dedicated to the development of requirements to support the definition, design, and demonstration of a distributed generation-electric power system interconnection interface concept. The report focuses on the dynamic behavior of power systems when a significant portion of the total energy resource is distributed generation. It also focuses on the near-term reality that the majority of new DG relies on rotating synchronous generators for energy conversion.

Electricity diversification, decentralization, and decarbonization: The role of U.S. state energy policy

NASA Astrophysics Data System (ADS)

Carley, Sanya

In response to mounting concerns about climate change and an over-dependence on fossil fuels, U.S. state governments have assumed leadership roles in energy policy. State leaders across the country have constructed policies that target electricity sector operations, and aim to increase the percentage of renewable electricity generation, increase the use of distributed generation, and decrease carbon footprints. The policy literature, however, lacks compelling empirical evidence that state initiatives toward these ends are effective. This research seeks to contribute empirical insights that can help fill this void in the literature, and advance policy knowledge about the efficacy of these instruments. This three-essay dissertation focuses on the assessment of state energy policy instruments aimed at the diversification, decentralization, and decarbonization of the U.S. electricity sector. The first essay considers the effects of state efforts to diversify electricity portfolios via increases in renewable energy. This essay asks: are state-level renewable portfolio standards (RPS) effective at increasing renewable energy deployment, as well as the share of renewable energy out of the total generation mix? Empirical results demonstrate that RPS policies so far are effectively encouraging total renewable energy deployment, but not the percentage of renewable energy generation. The second essay considers state policy efforts to decentralize the U.S. electricity sector via instruments that remove barriers to distributed generation (DG) deployment. The primary question this essay addresses is whether the removal of legal barriers acts as a primary motivating factor for DG deployment. Empirical results reveal that net metering policies are positively associated with DG deployment; interconnection standards significantly increase the likelihood that end-users will adopt DG capacity; and utility DG adoption is related to standard market forces. The third essay asks: what are the potential effects of state energy policy portfolios on carbon emissions within the U.S. electricity sector? The results from an electricity modeling scenario analysis reveal that state policy portfolios have modest to minimal carbon mitigation effects in the long run if surrounding states do not adopt similar portfolios as well. The effectiveness of state-level policy portfolios can increase significantly if surrounding states adopt similar portfolios, or with the introduction of a national carbon price.

Optimal reactive power planning for distribution systems considering intermittent wind power using Markov model and genetic algorithm

NASA Astrophysics Data System (ADS)

Li, Cheng

Wind farms, photovoltaic arrays, fuel cells, and micro-turbines are all considered to be Distributed Generation (DG). DG is defined as the generation of power which is dispersed throughout a utility's service territory and either connected to the utility's distribution system or isolated in a small grid. This thesis addresses modeling and economic issues pertaining to the optimal reactive power planning for distribution system with wind power generation (WPG) units. Wind farms are inclined to cause reverse power flows and voltage variations due to the random-like outputs of wind turbines. To deal with this kind of problem caused by wide spread usage of wind power generation, this thesis investigates voltage and reactive power controls in such a distribution system. Consequently static capacitors (SC) and transformer taps are introduced into the system and treated as controllers. For the purpose of getting optimum voltage and realizing reactive power control, the research proposes a proper coordination among the controllers like on-load tap changer (OLTC), feeder-switched capacitors. What's more, in order to simulate its uncertainty, the wind power generation is modeled by the Markov model. In that way, calculating the probabilities for all the scenarios is possible. Some outputs with consecutive and discrete values have been used for transition between successive time states and within state wind speeds. The thesis will describe the method to generate the wind speed time series from the transition probability matrix. After that, utilizing genetic algorithm, the optimal locations of SCs, the sizes of SCs and transformer taps are determined so as to minimize the cost or minimize the power loss, and more importantly improve voltage profiles. The applicability of the proposed method is verified through simulation on a 9-bus system and a 30-bus system respectively. At last, the simulation results indicate that as long as the available capacitors are able to sufficiently compensate the reactive power demand, the DG operation no longer imposes a significant effect on the voltage fluctuations in the distribution system. And the proposed approach is efficient, simple and straightforward.

An optimal autonomous microgrid cluster based on distributed generation droop parameter optimization and renewable energy sources using an improved grey wolf optimizer

NASA Astrophysics Data System (ADS)

Moazami Goodarzi, Hamed; Kazemi, Mohammad Hosein

2018-05-01

Microgrid (MG) clustering is regarded as an important driver in improving the robustness of MGs. However, little research has been conducted on providing appropriate MG clustering. This article addresses this shortfall. It proposes a novel multi-objective optimization approach for finding optimal clustering of autonomous MGs by focusing on variables such as distributed generation (DG) droop parameters, the location and capacity of DG units, renewable energy sources, capacitors and powerline transmission. Power losses are minimized and voltage stability is improved while virtual cut-set lines with minimum power transmission for clustering MGs are obtained. A novel chaotic grey wolf optimizer (CGWO) algorithm is applied to solve the proposed multi-objective problem. The performance of the approach is evaluated by utilizing a 69-bus MG in several scenarios.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoffman, Michael G.; Srivastava, Viraj; Wagner, Anne W.

The Pacific Northwest National Laboratory (PNNL) has launched a project funded by the Bonneville Power Association (BPA) to identify strategies for increasing industrial energy efficiency and reducing energy costs of Northwest Food Processors Association (NWFPA) plants through deployment of novel combinations and designs of variable-output combined heat and power (CHP) distributed generation (DG), combined cooling, heating and electric power (CCHP) DG and energy storage systems. Detailed evaluations and recommendations of CHP and CCHP DG systems will be performed for several Northwest (NW) food processing sites. The objective is to reduce the overall energy use intensity of NW food processors bymore » 25% by 2020 and by 50% by 2030, as well as reducing emissions and understanding potential congestion reduction impacts on the transmission system in the Pacific Northwest.« less

Waste-to-Energy Technology Brief

EPA Science Inventory

ETV's Greenhouse Gas Technology (GHG) Center, operated by Southern Research Institute under a cooperative agreement with US EPA, verified two biogas processing systems and four distributed generation (DG) energy systems in collaboration with the Colorado Governors Office or the N...

DGIC Interconnection Insights | Distributed Generation Interconnection

Science.gov Websites

appointed by the "Government/Customer" stakeholder group (one member) or the "DG Industry group. That is, the value of such a group (and the willpower to establish one) may be much less evident Distributed Resources Collaborative, California Smart Inverter Working Group, and Massachusetts Technical

Breast dose in mammography is about 30% lower when realistic heterogeneous glandular distributions are considered

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hernandez, Andrew M., E-mail: amhern@ucdavis.edu; Seibert, J. Anthony; Boone, John M.

2015-11-15

Purpose: Current dosimetry methods in mammography assume that the breast is comprised of a homogeneous mixture of glandular and adipose tissues. Three-dimensional (3D) dedicated breast CT (bCT) data sets were used previously to assess the complex anatomical structure within the breast, characterizing the statistical distribution of glandular tissue in the breast. The purpose of this work was to investigate the effect of bCT-derived heterogeneous glandular distributions on dosimetry in mammography. Methods: bCT-derived breast diameters, volumes, and 3D fibroglandular distributions were used to design realistic compressed breast models comprised of heterogeneous distributions of glandular tissue. The bCT-derived glandular distributions were fitmore » to biGaussian functions and used as probability density maps to assign the density distributions within compressed breast models. The MCNPX 2.6.0 Monte Carlo code was used to estimate monoenergetic normalized mean glandular dose “DgN(E)” values in mammography geometry. The DgN(E) values were then weighted by typical mammography x-ray spectra to determine polyenergetic DgN (pDgN) coefficients for heterogeneous (pDgN{sub hetero}) and homogeneous (pDgN{sub homo}) cases. The dependence of estimated pDgN values on phantom size, volumetric glandular fraction (VGF), x-ray technique factors, and location of the heterogeneous glandular distributions was investigated. Results: The pDgN{sub hetero} coefficients were on average 35.3% (SD, 4.1) and 24.2% (SD, 3.0) lower than the pDgN{sub homo} coefficients for the Mo–Mo and W–Rh x-ray spectra, respectively, across all phantom sizes and VGFs when the glandular distributions were centered within the breast phantom in the coronal plane. At constant breast size, increasing VGF from 7.3% to 19.1% lead to a reduction in pDgN{sub hetero} relative to pDgN{sub homo} of 23.6%–27.4% for a W–Rh spectrum. Displacement of the glandular distribution, at a distance equal to 10% of the compressed breast width in the superior and inferior directions, resulted in a 37.3% and a −26.6% change in the pDgN{sub hetero} coefficient, respectively, relative to the centered distribution for the Mo–Mo spectrum. Lateral displacement of the glandular distribution, at a distance equal to 10% of the compressed breast width, resulted in a 1.5% change in the pDgN{sub hetero} coefficient relative to the centered distribution for the W–Rh spectrum. Conclusions: Introducing bCT-derived heterogeneous glandular distributions into mammography phantom design resulted in decreased glandular dose relative to the widely used homogeneous assumption. A homogeneous distribution overestimates the amount of glandular tissue near the entrant surface of the breast, where dose deposition is exponentially higher. While these findings are based on clinically measured distributions of glandular tissue using a large cohort of women, future work is required to improve the classification of glandular distributions based on breast size and overall glandular fraction.« less

Histamine release factor from Dermanyssus gallinae (De Geer): characterization and in vitro assessment as a protective antigen.

PubMed

Bartley, Kathryn; Nisbet, Alasdair J; Offer, Jill E; Sparks, Nicholas H C; Wright, Harry W; Huntley, John F

2009-03-01

A cDNA encoding a 174-amino-acid orthologue of a tick histamine release factor (HRF) was identified from the haematophagous poultry red mite Dermanyssus gallinae. The predicted D. gallinae HRF protein (Dg-HRF-1) sequence is highly conserved with the tick HRFs (identity 52-54%) and to a lesser degree with translationally controlled tumour proteins (TCTP) from mammals and other invertebrates (range 38-47%). Phylogenetically, Dg-HRF-1 partitions with the tick HRF clade suggesting a shared linage and potentially similar function(s). A recombinant Dg-HRF-1 protein (rDg-HRF-1) was produced and shown to induce degranulation of rat peritoneal mast cells in vitro, confirming conservation of the histamine-releasing function in D. gallinae. Polyclonal antibodies were generated in rabbits and hens to rDg-HRF-1. Western blotting demonstrated that native Dg-HRF is a soluble protein and immunohistochemical staining of mite sections revealed that the distribution of Dg-HRF, although ubiquitous, is more common in mite reproductive, digestive and synganglion tissues. A survey of hens housed continuously in a mite-infested commercial poultry unit failed to identify IgY specific for recombinant or native Dg-HRF, indicating that Dg-HRF is not exposed to the host during infestation/feeding and may therefore have potential as a vaccine using the concealed antigen approach. To test the protective capability of rDg-HRF-1, fresh heparinised chicken blood was enriched with yolk-derived anti-Dg-HRF IgY antibodies and fed to semi-starved mites using an in vitro feeding system. A statistically significant increase in mortality was shown (P=0.004) in mites fed with anti-Dg-HRF IgY after just one blood meal. The work presented here demonstrates, to our knowledge for the first time, the feasibility of vaccinating hens with recombinant D. gallinae antigens to control mite infestation and the potential of rDg-HRF-1 as a vaccine antigen.

Protective Controller against Cascade Outages with Selective Harmonic Compensation Function

NASA Astrophysics Data System (ADS)

Abramovich, B. N.; Kuznetsov, P. A.; Sychev, Yu A.

2018-05-01

The paper presents data on the power quality and development of protective devices for the power networks with distributed generation (DG).The research has shown that power quality requirements for DG networks differ from conventional ones. That is why main tendencies, protective equipment and filters should be modified. There isa developed algorithm for detection and prevention of cascade outages that can lead to the blackoutin DG networks and there was a proposed structural scheme for a new active power filter for selective harmonics compensation. Analysis of these theories and equipment led to the development of protective device that could monitor power balance and cut off non-important consumers. The last part of the article describes a microcontroller prototype developed for connection to the existing power station control center.

Optimization of active distribution networks: Design and analysis of significative case studies for enabling control actions of real infrastructure

NASA Astrophysics Data System (ADS)

Moneta, Diana; Mora, Paolo; Viganò, Giacomo; Alimonti, Gianluca

2014-12-01

The diffusion of Distributed Generation (DG) based on Renewable Energy Sources (RES) requires new strategies to ensure reliable and economic operation of the distribution networks and to support the diffusion of DG itself. An advanced algorithm (DISCoVER - DIStribution Company VoltagE Regulator) is being developed to optimize the operation of active network by means of an advanced voltage control based on several regulations. Starting from forecasted load and generation, real on-field measurements, technical constraints and costs for each resource, the algorithm generates for each time period a set of commands for controllable resources that guarantees achievement of technical goals minimizing the overall cost. Before integrating the controller into the telecontrol system of the real networks, and in order to validate the proper behaviour of the algorithm and to identify possible critical conditions, a complete simulation phase has started. The first step is concerning the definition of a wide range of "case studies", that are the combination of network topology, technical constraints and targets, load and generation profiles and "costs" of resources that define a valid context to test the algorithm, with particular focus on battery and RES management. First results achieved from simulation activity on test networks (based on real MV grids) and actual battery characteristics are given, together with prospective performance on real case applications.

Integrated Field Testing of Fuel Cells and Micro-Turbines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jerome R. Temchin; Stephen J. Steffel

A technical and economic evaluation of the prospects for the deployment of distributed generation on Long Beach Island, New Jersey concluded that properly sited DG would defer upgrading of the electric power grid for 10 years. This included the deployment of fuel cells or microturbines as well as reciprocating engines. The implementation phase of this project focused on the installation of a 120 kW CHP microturbine system at the Harvey Cedars Bible Conference in Harvey Cedars, NJ. A 1.1 MW generator powered by a gas-fired reciprocating engine for additional grid support was also installed at a local substation. This reportmore » contains installation and operation issues as well as the utility perspective on DG deployment.« less

Modeling and control of hybrid wind/photovoltaic/fuel cell distributed generation systems

NASA Astrophysics Data System (ADS)

Wang, Caisheng

Due to ever increasing energy consumption, rising public awareness of environmental protection, and steady progress in power deregulation, alternative (i.e., renewable and fuel cell based) distributed generation (DG) systems have attracted increased interest. Wind and photovoltaic (PV) power generation are two of the most promising renewable energy technologies. Fuel cell (FC) systems also show great potential in DG applications of the future due to their fast technology development and many merits they have, such as high efficiency, zero or low emission (of pollutant gases) and flexible modular structure. The modeling and control of a hybrid wind/PV/FC DG system is addressed in this dissertation. Different energy sources in the system are integrated through an AC bus. Dynamic models for the main system components, namely, wind energy conversion system (WECS), PV energy conversion system (PVECS), fuel cell, electrolyzer, power electronic interfacing circuits, battery, hydrogen storage tank, gas compressor and gas pressure regulator, are developed. Two types of fuel cells have been modeled in this dissertation: proton exchange membrane fuel cell (PEMFC) and solid oxide fuel cell (SOFC). Power control of a grid-connected FC system as well as load mitigation control of a stand-alone FC system are investigated. The pitch angle control for WECS, the maximum power point tracking (MPPT) control for PVECS, and the control for electrolyzer and power electronic devices, are also addressed in the dissertation. Based on the dynamic component models, a simulation model for the proposed hybrid energy system has been developed using MATLAB/Simulink. The overall power management strategy for coordinating the power flows among the different energy sources is presented in the dissertation. Simulation studies have been carried out to verify the system performance under different scenarios using a practical load profile and real weather data. The results show that the overall power management strategy is effective and the power flows among the different energy sources and the load demand is balanced successfully. The DG's impacts on the existing power system are also investigated in this dissertation. Analytical methods for finding optimal sites to deploy DG sources in power systems are presented and verified with simulation studies.

Bidding strategy for microgrid in day-ahead market based on hybrid stochastic/robust optimization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Guodong; Xu, Yan; Tomsovic, Kevin

In this paper, we propose an optimal bidding strategy in the day-ahead market of a microgrid consisting of intermittent distributed generation (DG), storage, dispatchable DG and price responsive loads. The microgrid coordinates the energy consumption or production of its components and trades electricity in both the day-ahead and real-time markets to minimize its operating cost as a single entity. The bidding problem is challenging due to a variety of uncertainties, including power output of intermittent DG, load variation, day-ahead and real-time market prices. A hybrid stochastic/robust optimization model is proposed to minimize the expected net cost, i.e., expected total costmore » of operation minus total benefit of demand. This formulation can be solved by mixed integer linear programming. The uncertain output of intermittent DG and day-ahead market price are modeled via scenarios based on forecast results, while a robust optimization is proposed to limit the unbalanced power in real-time market taking account of the uncertainty of real-time market price. Numerical simulations on a microgrid consisting of a wind turbine, a PV panel, a fuel cell, a micro-turbine, a diesel generator, a battery and a responsive load show the advantage of stochastic optimization in addition to robust optimization.« less

Bidding strategy for microgrid in day-ahead market based on hybrid stochastic/robust optimization

DOE PAGES

Liu, Guodong; Xu, Yan; Tomsovic, Kevin

2016-01-01

In this paper, we propose an optimal bidding strategy in the day-ahead market of a microgrid consisting of intermittent distributed generation (DG), storage, dispatchable DG and price responsive loads. The microgrid coordinates the energy consumption or production of its components and trades electricity in both the day-ahead and real-time markets to minimize its operating cost as a single entity. The bidding problem is challenging due to a variety of uncertainties, including power output of intermittent DG, load variation, day-ahead and real-time market prices. A hybrid stochastic/robust optimization model is proposed to minimize the expected net cost, i.e., expected total costmore » of operation minus total benefit of demand. This formulation can be solved by mixed integer linear programming. The uncertain output of intermittent DG and day-ahead market price are modeled via scenarios based on forecast results, while a robust optimization is proposed to limit the unbalanced power in real-time market taking account of the uncertainty of real-time market price. Numerical simulations on a microgrid consisting of a wind turbine, a PV panel, a fuel cell, a micro-turbine, a diesel generator, a battery and a responsive load show the advantage of stochastic optimization in addition to robust optimization.« less

Mapping analysis of scaffold/matrix attachment regions (s/MARs) from two different mammalian cell lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pilus, Nur Shazwani Mohd; Ahmad, Azrin; Yusof, Nurul Yuziana Mohd

Scaffold/matrix attachment regions (S/MARs) are potential element that can be integrated into expression vector to increase expression of recombinant protein. Many studies on S/MAR have been done but none has revealed the distribution of S/MAR in a genome. In this study, we have isolated S/MAR sequences from HEK293 and Chinese hamster ovary cell lines (CHO DG44) using two different methods utilizing 2 M NaCl and lithium-3,5-diiodosalicylate (LIS). The isolated S/MARs were sequenced using Next Generation Sequencing (NGS) platform. Based on reference mapping analysis against human genome database, a total of 8,994,856 and 8,412,672 contigs of S/MAR sequences were retrieved frommore » 2M NaCl and LIS extraction of HEK293 respectively. On the other hand, reference mapping analysis of S/MAR derived from CHO DG44 against our own CHO DG44 database have generated a total of 7,204,348 and 4,672,913 contigs from 2 M NaCl and LIS extraction method respectively.« less

An Efficacious Multi-Objective Fuzzy Linear Programming Approach for Optimal Power Flow Considering Distributed Generation.

PubMed

Warid, Warid; Hizam, Hashim; Mariun, Norman; Abdul-Wahab, Noor Izzri

2016-01-01

This paper proposes a new formulation for the multi-objective optimal power flow (MOOPF) problem for meshed power networks considering distributed generation. An efficacious multi-objective fuzzy linear programming optimization (MFLP) algorithm is proposed to solve the aforementioned problem with and without considering the distributed generation (DG) effect. A variant combination of objectives is considered for simultaneous optimization, including power loss, voltage stability, and shunt capacitors MVAR reserve. Fuzzy membership functions for these objectives are designed with extreme targets, whereas the inequality constraints are treated as hard constraints. The multi-objective fuzzy optimal power flow (OPF) formulation was converted into a crisp OPF in a successive linear programming (SLP) framework and solved using an efficient interior point method (IPM). To test the efficacy of the proposed approach, simulations are performed on the IEEE 30-busand IEEE 118-bus test systems. The MFLP optimization is solved for several optimization cases. The obtained results are compared with those presented in the literature. A unique solution with a high satisfaction for the assigned targets is gained. Results demonstrate the effectiveness of the proposed MFLP technique in terms of solution optimality and rapid convergence. Moreover, the results indicate that using the optimal DG location with the MFLP algorithm provides the solution with the highest quality.

An Efficacious Multi-Objective Fuzzy Linear Programming Approach for Optimal Power Flow Considering Distributed Generation

PubMed Central

Warid, Warid; Hizam, Hashim; Mariun, Norman; Abdul-Wahab, Noor Izzri

2016-01-01

This paper proposes a new formulation for the multi-objective optimal power flow (MOOPF) problem for meshed power networks considering distributed generation. An efficacious multi-objective fuzzy linear programming optimization (MFLP) algorithm is proposed to solve the aforementioned problem with and without considering the distributed generation (DG) effect. A variant combination of objectives is considered for simultaneous optimization, including power loss, voltage stability, and shunt capacitors MVAR reserve. Fuzzy membership functions for these objectives are designed with extreme targets, whereas the inequality constraints are treated as hard constraints. The multi-objective fuzzy optimal power flow (OPF) formulation was converted into a crisp OPF in a successive linear programming (SLP) framework and solved using an efficient interior point method (IPM). To test the efficacy of the proposed approach, simulations are performed on the IEEE 30-busand IEEE 118-bus test systems. The MFLP optimization is solved for several optimization cases. The obtained results are compared with those presented in the literature. A unique solution with a high satisfaction for the assigned targets is gained. Results demonstrate the effectiveness of the proposed MFLP technique in terms of solution optimality and rapid convergence. Moreover, the results indicate that using the optimal DG location with the MFLP algorithm provides the solution with the highest quality. PMID:26954783

Bone morphogenetic protein signaling in the developing telencephalon controls formation of the hippocampal dentate gyrus and modifies fear-related behavior.

PubMed

Caronia, Giuliana; Wilcoxon, Jennifer; Feldman, Polina; Grove, Elizabeth A

2010-05-05

The cortical hem is an embryonic signaling center that generates bone morphogenetic proteins (BMPs) and acts as an organizer for the hippocampus. The role of BMP signaling in hippocampal neurogenesis, however, has not been established. We therefore generated mice that were deficient in Bmpr1b constitutively, and deficient in Bmpr1a conditionally in the dorsal telencephalon. In double mutant male and female mice, the dentate gyrus (DG) was dramatically smaller than in control mice, reflecting decreased production of granule neurons at the peak period of DG neurogenesis. Additionally, the pool of cells that generates new DG neurons throughout life was reduced, commensurate with the smaller size of the DG. Effects of diminished BMP signaling on the cortical hem were at least partly responsible for these defects in DG development. Reduction of the DG and its major extrinsic output to CA3 raised the possibility that the DG was functionally compromised. We therefore looked for behavioral deficits in double mutants and found that the mice were less responsive to fear- or anxiety-provoking stimuli, whether the association of the stimulus with fear or anxiety was learned or innate. Given that no anatomical defects appeared in the double mutant telencephalon outside the DG, our observations support a growing literature that implicates the hippocampus in circuitry mediating fear and anxiety. Our results additionally indicate a requirement for BMP signaling in generating the dorsalmost neuronal lineage of the telencephalon, DG granule neurons, and in the development of the stem cell niche that makes neurons in the adult hippocampus.

Neurogenin 2 has an essential role in development of the dentate gyrus.

PubMed

Galichet, Christophe; Guillemot, François; Parras, Carlos M

2008-06-01

The dentate gyrus (DG) of the hippocampus has a central role in learning and memory in adult rodents. The DG is generated soon after birth, although new neurons continue to be generated in the DG throughout life. The proneural factors Mash1 (Ascl1) and neurogenin 2 (Ngn2) are expressed during formation of the DG but their role in the development of this structure has not yet been addressed. Here, we show that Ngn2 is essential for the development of the DG. Ngn2 mutant mice have fewer DG progenitors and these cells present defects in neuronal differentiation. By contrast, the DG is normal in Mash1 mutant mice at birth, and loss of both Mash1 and Ngn2 does not aggravate the defect observed in Ngn2 single mutants. These data establish a unique role of Ngn2 in DG neurogenesis during development and raise the possibility that Ngn2 has a similar function in adult neurogenesis.

Finite Control Set Model Predictive Control for Multiple Distributed Generators Microgrids

NASA Astrophysics Data System (ADS)

Babqi, Abdulrahman Jamal

This dissertation proposes two control strategies for AC microgrids that consist of multiple distributed generators (DGs). The control strategies are valid for both grid-connected and islanded modes of operation. In general, microgrid can operate as a stand-alone system (i.e., islanded mode) or while it is connected to the utility grid (i.e., grid connected mode). To enhance the performance of a micrgorid, a sophisticated control scheme should be employed. The control strategies of microgrids can be divided into primary and secondary controls. The primary control regulates the output active and reactive powers of each DG in grid-connected mode as well as the output voltage and frequency of each DG in islanded mode. The secondary control is responsible for regulating the microgrid voltage and frequency in the islanded mode. Moreover, it provides power sharing schemes among the DGs. In other words, the secondary control specifies the set points (i.e. reference values) for the primary controllers. In this dissertation, Finite Control Set Model Predictive Control (FCS-MPC) was proposed for controlling microgrids. FCS-MPC was used as the primary controller to regulate the output power of each DG (in the grid-connected mode) or the voltage of the point of DG coupling (in the islanded mode of operation). In the grid-connected mode, Direct Power Model Predictive Control (DPMPC) was implemented to manage the power flow between each DG and the utility grid. In the islanded mode, Voltage Model Predictive Control (VMPC), as the primary control, and droop control, as the secondary control, were employed to control the output voltage of each DG and system frequency. The controller was equipped with a supplementary current limiting technique in order to limit the output current of each DG in abnormal incidents. The control approach also enabled smooth transition between the two modes. The performance of the control strategy was investigated and verified using PSCAD/EMTDC software platform. This dissertation also proposes a control and power sharing strategy for small-scale microgrids in both grid-connected and islanded modes based on centralized FCS-MPC. In grid-connected mode, the controller was capable of managing the output power of each DG and enabling flexible power regulation between the microgrid and the utility grid. In islanded mode, the controller regulated the microgrid voltage and frequency, and provided a precise power sharing scheme among the DGs. In addition, the power sharing can be adjusted flexibly by changing the sharing ratio. The proposed control also enabled plug-and-play operation. Moreover, a smooth transition between the two modes of operation was achieved without any disturbance in the system. Case studies were carried out in order to validate the proposed control strategy with the PSCAD/EMTDA software package.

Optimal Operation of Energy Storage in Power Transmission and Distribution

NASA Astrophysics Data System (ADS)

Akhavan Hejazi, Seyed Hossein

In this thesis, we investigate optimal operation of energy storage units in power transmission and distribution grids. At transmission level, we investigate the problem where an investor-owned independently-operated energy storage system seeks to offer energy and ancillary services in the day-ahead and real-time markets. We specifically consider the case where a significant portion of the power generated in the grid is from renewable energy resources and there exists significant uncertainty in system operation. In this regard, we formulate a stochastic programming framework to choose optimal energy and reserve bids for the storage units that takes into account the fluctuating nature of the market prices due to the randomness in the renewable power generation availability. At distribution level, we develop a comprehensive data set to model various stochastic factors on power distribution networks, with focus on networks that have high penetration of electric vehicle charging load and distributed renewable generation. Furthermore, we develop a data-driven stochastic model for energy storage operation at distribution level, where the distribution of nodal voltage and line power flow are modelled as stochastic functions of the energy storage unit's charge and discharge schedules. In particular, we develop new closed-form stochastic models for such key operational parameters in the system. Our approach is analytical and allows formulating tractable optimization problems. Yet, it does not involve any restricting assumption on the distribution of random parameters, hence, it results in accurate modeling of uncertainties. By considering the specific characteristics of random variables, such as their statistical dependencies and often irregularly-shaped probability distributions, we propose a non-parametric chance-constrained optimization approach to operate and plan energy storage units in power distribution girds. In the proposed stochastic optimization, we consider uncertainty from various elements, such as solar photovoltaic , electric vehicle chargers, and residential baseloads, in the form of discrete probability functions. In the last part of this thesis we address some other resources and concepts for enhancing the operation of power distribution and transmission systems. In particular, we proposed a new framework to determine the best sites, sizes, and optimal payment incentives under special contracts for committed-type DG projects to offset distribution network investment costs. In this framework, the aim is to allocate DGs such that the profit gained by the distribution company is maximized while each DG unit's individual profit is also taken into account to assure that private DG investment remains economical.

The Case for Natural Gas Fueled Solid Oxide Fuel Cell Power Systems for Distributed Generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chick, Lawrence A.; Weimar, Mark R.; Whyatt, Greg A.

2015-02-01

Natural-gas-fueled solid oxide fuel cell (NGSOFC) power systems yield electrical conversion efficiencies exceeding 60% and may become a viable alternative for distributed generation (DG) if stack life and manufacturing economies of scale can be realized. Currently, stacks last approximately 2 years and few systems are produced each year because of the relatively high cost of electricity from the systems. If mass manufacturing (10,000 units per year) and a stack life of 15 years can be reached, the cost of electricity from an NGSOFC system is estimated to be about 7.7 ¢/kWh, well within the price of commercial and residential retailmore » prices at the national level (9.9-10¢/kWh and 11-12 ¢/kWh, respectively). With an additional 5 ¢/kWh in estimated additional benefits from DG, NGSOFC could be well positioned to replace the forecasted 59-77 gigawatts of capacity loss resulting from coal plant closures due to stricter emissions regulations and low natural gas prices.« less

Nonlinear adaptive control of grid-connected three-phase inverters for renewable energy applications

NASA Astrophysics Data System (ADS)

Mahdian-Dehkordi, N.; Namvar, M.; Karimi, H.; Piya, P.; Karimi-Ghartemani, M.

2017-01-01

Distributed generation (DG) units are often interfaced to the main grid using power electronic converters including voltage-source converters (VSCs). A VSC offers dc/ac power conversion, high controllability, and fast dynamic response. Because of nonlinearities, uncertainties, and system parameters' changes involved in the nature of a grid-connected renewable DG system, conventional linear control methods cannot completely and efficiently address all control objectives. In this paper, a nonlinear adaptive control scheme based on adaptive backstepping strategy is presented to control the operation of a grid-connected renewable DG unit. As compared to the popular vector control technique, the proposed controller offers smoother transient responses, and lower level of current distortions. The Lyapunov approach is used to establish global asymptotic stability of the proposed control system. Linearisation technique is employed to develop guidelines for parameters tuning of the controller. Extensive time-domain digital simulations are performed and presented to verify the performance of the proposed controller when employed in a VSC to control the operation of a two-stage DG unit and also that of a single-stage solar photovoltaic system. Desirable and superior performance of the proposed controller is observed.

Incongruity of imaging using fluorescent 2-DG conjugates compared to 18F-FDG in preclinical cancer models.

PubMed

Tseng, Jen-Chieh; Wang, Yuchuan; Banerjee, Pallab; Kung, Andrew L

2012-10-01

We compared the use of near-infrared conjugates of 2-deoxyglucose (NIR 2-DG) to 2-deoxy-2-[18F]fluoro-d-glucose (18F-FDG) for the purposes of imaging tumors, as well as response to therapy. Uptake of both 18F-FDG and NIR 2-DG within gastrointestinal stromal tumor xenografts were imaged before and after nilotinib treatment. Confocal microscopy was performed to determine NIR 2-DG distribution in tumors. Treatment with nilotinib resulted in a rapid reduction in 18F-FDG uptake and reduced tumor cell viability which was predictive of long-term antitumor efficacy. In contrast, optical imaging with NIR 2-DG probes was unable to differentiate control from niltonib-treated animals, and microscopic analysis revealed no change in probe distribution as a result of treatment. These results suggest that conjugation of large bulky fluorophores to 2-DG disrupts the facilitated transport and retention of these probes in cells. Therefore, optical imaging of NIR 2-DG probes cannot substitute for 18F-FDG positron emission tomography imaging as a biomarker of tumor cell viability and metabolism.

Dynamic analysis of combined photovoltaic source and synchronous generator connected to power grid

NASA Astrophysics Data System (ADS)

Mahabal, Divya

In the world of expanding economy and technology, the energy demand is likely to increase even with the global efforts of saving and increasing energy efficiency. Higher oil prices, effects of greenhouse gases, and concerns over other environmental impacts gave way to Distributed Generation (DG). With adequate awareness and support, DG's can meet these rising energy demands at lower prices compared to conventional methods. Extensive research is taking place in different areas like fuel cells, photovoltaic cells, wind turbines, and gas turbines. DG's when connected to a grid increase the overall efficiency of the power grid. It is believed that three-fifth of the world's electricity would account for renewable energy by middle of 21st century. This thesis presents the dynamic analysis of a grid connected photovoltaic (PV) system and synchronous generator. A grid is considered as an infinite bus. The photovol-taic system and synchronous generator act as small scale distributed energy resources. The output of the photovoltaic system depends on the light intensity, temperature, and irradiance levels of sun. The maximum power point tracking and DC/AC converter are also modeled for the photovoltaic system. The PV system is connected to the grid through DC/AC system. Different combinations of PV and synchronous generator are modeled with the grid to study the dynamics of the proposed system. The dynamics of the test system is analyzed by subjecting the system to several disturbances under various conditions. All modules are individually modeled and con-nected using MATLAB/Simulink software package. Results from the study show that, as the penetration of renewable energy sources like PV increases into the power system, the dynamics of the system becomes faster. When considering cases such as load switching, PV cannot deliver more power as the performance of PV depends on environmental conditions. Synchronous generator in power system can produce the required amount of power. As the main aim of this research is to use renewable sources like PV in the system, it is advantageous to use a combination of both PV and synchronous generator in the system.

Laying the Groundwork: Lessons Learned from the Telecommunications Industry for Distributed Generation; Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wise, A. L.

2008-05-01

The telecommunications industry went through growing pains in the past that hold some interesting lessons for the growing distributed generation (DG) industry. The technology shifts and stakeholders involved with the historic market transformation of the telecommunications sector mirror similar factors involved in distributed generation today. An examination of these factors may inform best practices when approaching the conduits necessary to accelerate the shifting of our nation's energy system to cleaner forms of generation and use. From a technical perspective, the telecom industry in the 1990s saw a shift from highly centralized systems that had no capacity for adaptation to highlymore » adaptive, distributed network systems. From a management perspective, the industry shifted from small, private-company structures to big, capital-intensive corporations. This presentation will explore potential correlation and outline the lessons that we can take away from this comparison.« less

Determination of Glucose Utilization Rates in Cultured Astrocytes and Neurons with [14C]deoxyglucose: Progress, Pitfalls, and Discovery of Intracellular Glucose Compartmentation.

PubMed

Dienel, Gerald A; Cruz, Nancy F; Sokoloff, Louis; Driscoll, Bernard F

2017-01-01

2-Deoxy-D-[ 14 C]glucose ([ 14 C]DG) is commonly used to determine local glucose utilization rates (CMR glc ) in living brain and to estimate CMR glc in cultured brain cells as rates of [ 14 C]DG phosphorylation. Phosphorylation rates of [ 14 C]DG and its metabolizable fluorescent analog, 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose (2-NBDG), however, do not take into account differences in the kinetics of transport and metabolism of [ 14 C]DG or 2-NBDG and glucose in neuronal and astrocytic cells in cultures or in single cells in brain tissue, and conclusions drawn from these data may, therefore, not be correct. As a first step toward the goal of quantitative determination of CMR glc in astrocytes and neurons in cultures, the steady-state intracellular-to-extracellular concentration ratios (distribution spaces) for glucose and [ 14 C]DG were determined in cultured striatal neurons and astrocytes as functions of extracellular glucose concentration. Unexpectedly, the glucose distribution spaces rose during extreme hypoglycemia, exceeding 1.0 in astrocytes, whereas the [ 14 C]DG distribution space fell at the lowest glucose levels. Calculated CMR glc was greatly overestimated in hypoglycemic and normoglycemic cells because the intracellular glucose concentrations were too high. Determination of the distribution space for [ 14 C]glucose revealed compartmentation of intracellular glucose in astrocytes, and probably, also in neurons. A smaller metabolic pool is readily accessible to hexokinase and communicates with extracellular glucose, whereas the larger pool is sequestered from hexokinase activity. A new experimental approach using double-labeled assays with DG and glucose is suggested to avoid the limitations imposed by glucose compartmentation on metabolic assays.

Reactive Power Compensation Using an Energy Management System

DTIC Science & Technology

2014-09-01

bulk power grid or independent of the grid in islanded mode using various DG sources ( photovoltaic panels, fuel cells, gas generators, batteries...developed in order to forecast the system’s response to both capacitive and inductive power demands on the grid. The process was then confirmed in a...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited REACTIVE POWER

2-Deoxy-D-glucose treatment induces ketogenesis, sustains mitochondrial function, and reduces pathology in female mouse model of Alzheimer's disease.

PubMed

Yao, Jia; Chen, Shuhua; Mao, Zisu; Cadenas, Enrique; Brinton, Roberta Diaz

2011-01-01

Previously, we demonstrated that mitochondrial bioenergetic deficits preceded Alzheimer's disease (AD) pathology in the female triple-transgenic AD (3xTgAD) mouse model. In parallel, 3xTgAD mice exhibited elevated expression of ketogenic markers, indicating a compensatory mechanism for energy production in brain. This compensatory response to generate an alternative fuel source was temporary and diminished with disease progression. To determine whether this compensatory alternative fuel system could be sustained, we investigated the impact of 2-deoxy-D-glucose (2-DG), a compound known to induce ketogenesis, on bioenergetic function and AD pathology burden in brain. 6-month-old female 3xTgAD mice were fed either a regular diet (AIN-93G) or a diet containing 0.04% 2-DG for 7 weeks. 2-DG diet significantly increased serum ketone body level and brain expression of enzymes required for ketone body metabolism. The 2-DG-induced maintenance of mitochondrial bioenergetics was paralleled by simultaneous reduction in oxidative stress. Further, 2-DG treated mice exhibited a significant reduction of both amyloid precursor protein (APP) and amyloid beta (Aβ) oligomers, which was paralleled by significantly increased α-secretase and decreased γ-secretase expression, indicating that 2-DG induced a shift towards a non-amyloidogenic pathway. In addition, 2-DG increased expression of genes involved in Aβ clearance pathways, degradation, sequestering, and transport. Concomitant with increased bioenergetic capacity and reduced β-amyloid burden, 2-DG significantly increased expression of neurotrophic growth factors, BDNF and NGF. Results of these analyses demonstrate that dietary 2-DG treatment increased ketogenesis and ketone metabolism, enhanced mitochondrial bioenergetic capacity, reduced β-amyloid generation and increased mechanisms of β-amyloid clearance. Further, these data link bioenergetic capacity with β-amyloid generation and demonstrate that β-amyloid burden was dynamic and reversible, as 2-DG reduced activation of the amyloidogenic pathway and increased mechanisms of β-amyloid clearance. Collectively, these data provide preclinical evidence for dietary 2-DG as a disease-modifying intervention to delay progression of bioenergetic deficits in brain and associated β-amyloid burden.

Effects of 2-deoxy-D-glucose administration on immune parameters in mice

NASA Technical Reports Server (NTRS)

Dreau, D.; Morton, D. S.; Foster, M.; Fowler, N.; Sonnenfeld, G.

1998-01-01

Physical exercise and diet alterations have been shown to affect immune parameters. Similar effects are also induced by the administration of the non-metabolizable glucose analog, 2-deoxy-D-glucose (2-DG). The current study was designed to characterize the effects of glucoprivation induced by 2-DG administration on leukocyte subset distribution and function. BDF1 mice (n = 8 per group) were injected intraperitoneally one or three times with 0, 500, 750, 1000 or 1500 mg/kg of 2-DG. Two hours after the last injection of 2-DG, immunological parameters were analyzed. A dose-dependent increase in plasma glucose concentrations of mice injected once with up to 1500 mg/kg of 2-DG was observed (p < 0.001). After either one or three injections of up to 1500 mg/kg of 2-DG, corticosterone levels, leukocyte counts in the spleen, and CD3+ cells in the thymus increased. In vitro proliferation of partially purified lymphocytes from the spleen in the presence of both concanavalin-A and lipopolysaccharide decreased in a dose dependent manner (p < 0.05). In addition, after three injections, the proportion of both thymocytes and splenocytes bearing alphabeta-TCR increased as the concentration of 2-DG increased (p < 0.01). These results demonstrate that 2-DG administration induced dose-dependent changes in both thymus and spleen cell distribution and function.

Software Comparison for Renewable Energy Deployment in a Distribution Network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, David Wenzhong; Muljadi, Eduard; Tian, Tian

The main objective of this report is to evaluate different software options for performing robust distributed generation (DG) power system modeling. The features and capabilities of four simulation tools, OpenDSS, GridLAB-D, CYMDIST, and PowerWorld Simulator, are compared to analyze their effectiveness in analyzing distribution networks with DG. OpenDSS and GridLAB-D, two open source software, have the capability to simulate networks with fluctuating data values. These packages allow the running of a simulation each time instant by iterating only the main script file. CYMDIST, a commercial software, allows for time-series simulation to study variations on network controls. PowerWorld Simulator, another commercialmore » tool, has a batch mode simulation function through the 'Time Step Simulation' tool, which obtains solutions for a list of specified time points. PowerWorld Simulator is intended for analysis of transmission-level systems, while the other three are designed for distribution systems. CYMDIST and PowerWorld Simulator feature easy-to-use graphical user interfaces (GUIs). OpenDSS and GridLAB-D, on the other hand, are based on command-line programs, which increase the time necessary to become familiar with the software packages.« less

Network integration of distributed power generation

NASA Astrophysics Data System (ADS)

Dondi, Peter; Bayoumi, Deia; Haederli, Christoph; Julian, Danny; Suter, Marco

The world-wide move to deregulation of the electricity and other energy markets, concerns about the environment, and advances in renewable and high efficiency technologies has led to major emphasis being placed on the use of small power generation units in a variety of forms. The paper reviews the position of distributed generation (DG, as these small units are called in comparison with central power plants) with respect to the installation and interconnection of such units with the classical grid infrastructure. In particular, the status of technical standards both in Europe and USA, possible ways to improve the interconnection situation, and also the need for decisions that provide a satisfactory position for the network operator (who remains responsible for the grid, its operation, maintenance and investment plans) are addressed.

A Three-Phase Microgrid Restoration Model Considering Unbalanced Operation of Distributed Generation

DOE PAGES

Wang, Zeyu; Wang, Jianhui; Chen, Chen

2016-12-07

Recent severe outages highlight the urgency of improving grid resiliency in the U.S. Microgrid formation schemes are proposed to restore critical loads after outages occur. Most distribution networks have unbalanced configurations that are not represented in sufficient detail by single-phase models. This study provides a microgrid formation plan that adopts a three-phase network model to represent unbalanced distribution networks. The problem formulation has a quadratic objective function with mixed-integer linear constraints. The three-phase network model enables us to examine the three-phase power outputs of distributed generators (DGs), preventing unbalanced operation that might trip DGs. Because the DG unbalanced operation constraintmore » is non-convex, an iterative process is presented that checks whether the unbalanced operation limits for DGs are satisfied after each iteration of optimization. We also develop a relatively conservative linear approximation on the unbalanced operation constraint to handle larger networks. Compared with the iterative solution process, the conservative linear approximation is able to accelerate the solution process at the cost of sacrificing optimality to a limited extent. Simulation in the IEEE 34 node and IEEE 123 test feeders indicate that the proposed method yields more practical microgrid formations results. In addition, this paper explores the coordinated operation of DGs and energy storage (ES) installations. The unbalanced three-phase outputs of ESs combined with the relatively balanced outputs of DGs could supply unbalanced loads. In conclusion, the case study also validates the DG-ES coordination.« less

A Three-Phase Microgrid Restoration Model Considering Unbalanced Operation of Distributed Generation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zeyu; Wang, Jianhui; Chen, Chen

Recent severe outages highlight the urgency of improving grid resiliency in the U.S. Microgrid formation schemes are proposed to restore critical loads after outages occur. Most distribution networks have unbalanced configurations that are not represented in sufficient detail by single-phase models. This study provides a microgrid formation plan that adopts a three-phase network model to represent unbalanced distribution networks. The problem formulation has a quadratic objective function with mixed-integer linear constraints. The three-phase network model enables us to examine the three-phase power outputs of distributed generators (DGs), preventing unbalanced operation that might trip DGs. Because the DG unbalanced operation constraintmore » is non-convex, an iterative process is presented that checks whether the unbalanced operation limits for DGs are satisfied after each iteration of optimization. We also develop a relatively conservative linear approximation on the unbalanced operation constraint to handle larger networks. Compared with the iterative solution process, the conservative linear approximation is able to accelerate the solution process at the cost of sacrificing optimality to a limited extent. Simulation in the IEEE 34 node and IEEE 123 test feeders indicate that the proposed method yields more practical microgrid formations results. In addition, this paper explores the coordinated operation of DGs and energy storage (ES) installations. The unbalanced three-phase outputs of ESs combined with the relatively balanced outputs of DGs could supply unbalanced loads. In conclusion, the case study also validates the DG-ES coordination.« less

Optimal Operation and Management for Smart Grid Subsumed High Penetration of Renewable Energy, Electric Vehicle, and Battery Energy Storage System

NASA Astrophysics Data System (ADS)

Shigenobu, Ryuto; Noorzad, Ahmad Samim; Muarapaz, Cirio; Yona, Atsushi; Senjyu, Tomonobu

2016-04-01

Distributed generators (DG) and renewable energy sources have been attracting special attention in distribution systems in all over the world. Renewable energies, such as photovoltaic (PV) and wind turbine generators are considered as green energy. However, a large amount of DG penetration causes voltage deviation beyond the statutory range and reverse power flow at interconnection points in the distribution system. If excessive voltage deviation occurs, consumer's electric devices might break and reverse power flow will also has a negative impact on the transmission system. Thus, mass interconnections of DGs has an adverse effect on both of the utility and the customer. Therefore, reactive power control method is proposed previous research by using inverters attached DGs for prevent voltage deviations. Moreover, battery energy storage system (BESS) is also proposed for resolve reverse power flow. In addition, it is possible to supply high quality power for managing DGs and BESSs. Therefore, this paper proposes a method to maintain voltage, active power, and reactive power flow at interconnection points by using cooperative controlled of PVs, house BESSs, EVs, large BESSs, and existing voltage control devices. This paper not only protect distribution system, but also attain distribution loss reduction and effectivity management of control devices. Therefore mentioned control objectives are formulated as an optimization problem that is solved by using the Particle Swarm Optimization (PSO) algorithm. Modified scheduling method is proposed in order to improve convergence probability of scheduling scheme. The effectiveness of the proposed method is verified by case studies results and by using numerical simulations in MATLAB®.

Siting and sizing of distributed generators based on improved simulated annealing particle swarm optimization.

PubMed

Su, Hongsheng

2017-12-18

Distributed power grids generally contain multiple diverse types of distributed generators (DGs). Traditional particle swarm optimization (PSO) and simulated annealing PSO (SA-PSO) algorithms have some deficiencies in site selection and capacity determination of DGs, such as slow convergence speed and easily falling into local trap. In this paper, an improved SA-PSO (ISA-PSO) algorithm is proposed by introducing crossover and mutation operators of genetic algorithm (GA) into SA-PSO, so that the capabilities of the algorithm are well embodied in global searching and local exploration. In addition, diverse types of DGs are made equivalent to four types of nodes in flow calculation by the backward or forward sweep method, and reactive power sharing principles and allocation theory are applied to determine initial reactive power value and execute subsequent correction, thus providing the algorithm a better start to speed up the convergence. Finally, a mathematical model of the minimum economic cost is established for the siting and sizing of DGs under the location and capacity uncertainties of each single DG. Its objective function considers investment and operation cost of DGs, grid loss cost, annual purchase electricity cost, and environmental pollution cost, and the constraints include power flow, bus voltage, conductor current, and DG capacity. Through applications in an IEEE33-node distributed system, it is found that the proposed method can achieve desirable economic efficiency and safer voltage level relative to traditional PSO and SA-PSO algorithms, and is a more effective planning method for the siting and sizing of DGs in distributed power grids.

Polyelectrolyte brush bilayers in weak interpenetration regime: Scaling theory and molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Desai, Parth Rakesh; Sinha, Shayandev; Das, Siddhartha

2018-03-01

We employ molecular dynamics (MD) simulations and develop scaling theories to quantify the equilibrium behavior of polyelectrolyte (PE) brush bilayers (BBLs) in the weakly interpenetrated regime, which is characterized by d0

Dentate network activity is necessary for spatial working memory by supporting CA3 sharp-wave ripple generation and prospective firing of CA3 neurons.

PubMed

Sasaki, Takuya; Piatti, Verónica C; Hwaun, Ernie; Ahmadi, Siavash; Lisman, John E; Leutgeb, Stefan; Leutgeb, Jill K

2018-02-01

Complex spatial working memory tasks have been shown to require both hippocampal sharp-wave ripple (SWR) activity and dentate gyrus (DG) neuronal activity. We therefore asked whether DG inputs to CA3 contribute to spatial working memory by promoting SWR generation. Recordings from DG and CA3 while rats performed a dentate-dependent working memory task on an eight-arm radial maze revealed that the activity of dentate neurons and the incidence rate of SWRs both increased during reward consumption. We then found reduced reward-related CA3 SWR generation without direct input from dentate granule neurons. Furthermore, CA3 cells with place fields in not-yet-visited arms preferentially fired during SWRs at reward locations, and these prospective CA3 firing patterns were more pronounced for correct trials and were dentate-dependent. These results indicate that coordination of CA3 neuronal activity patterns by DG is necessary for the generation of neuronal firing patterns that support goal-directed behavior and memory.

DG-AMMOS: a new tool to generate 3d conformation of small molecules using distance geometry and automated molecular mechanics optimization for in silico screening.

PubMed

Lagorce, David; Pencheva, Tania; Villoutreix, Bruno O; Miteva, Maria A

2009-11-13

Discovery of new bioactive molecules that could enter drug discovery programs or that could serve as chemical probes is a very complex and costly endeavor. Structure-based and ligand-based in silico screening approaches are nowadays extensively used to complement experimental screening approaches in order to increase the effectiveness of the process and facilitating the screening of thousands or millions of small molecules against a biomolecular target. Both in silico screening methods require as input a suitable chemical compound collection and most often the 3D structure of the small molecules has to be generated since compounds are usually delivered in 1D SMILES, CANSMILES or in 2D SDF formats. Here, we describe the new open source program DG-AMMOS which allows the generation of the 3D conformation of small molecules using Distance Geometry and their energy minimization via Automated Molecular Mechanics Optimization. The program is validated on the Astex dataset, the ChemBridge Diversity database and on a number of small molecules with known crystal structures extracted from the Cambridge Structural Database. A comparison with the free program Balloon and the well-known commercial program Omega generating the 3D of small molecules is carried out. The results show that the new free program DG-AMMOS is a very efficient 3D structure generator engine. DG-AMMOS provides fast, automated and reliable access to the generation of 3D conformation of small molecules and facilitates the preparation of a compound collection prior to high-throughput virtual screening computations. The validation of DG-AMMOS on several different datasets proves that generated structures are generally of equal quality or sometimes better than structures obtained by other tested methods.

An islanding detection methodology combining decision trees and Sandia frequency shift for inverter-based distributed generations

DOE PAGES

Azim, Riyasat; Li, Fangxing; Xue, Yaosuo; ...

2017-07-14

Distributed generations (DGs) for grid-connected applications require an accurate and reliable islanding detection methodology (IDM) for secure system operation. This paper presents an IDM for grid-connected inverter-based DGs. The proposed method is a combination of passive and active islanding detection techniques for aggregation of their advantages and elimination/minimisation of the drawbacks. In the proposed IDM, the passive method utilises critical system attributes extracted from local voltage measurements at target DG locations as well as employs decision tree-based classifiers for characterisation and detection of islanding events. The active method is based on Sandia frequency shift technique and is initiated only whenmore » the passive method is unable to differentiate islanding events from other system events. Thus, the power quality degradation introduced into the system by active islanding detection techniques can be minimised. Furthermore, a combination of active and passive techniques allows detection of islanding events under low power mismatch scenarios eliminating the disadvantage associated with the use of passive techniques alone. Finally, detailed case study results demonstrate the effectiveness of the proposed method in detection of islanding events under various power mismatch scenarios, load quality factors and in the presence of single or multiple grid-connected inverter-based DG units.« less

An islanding detection methodology combining decision trees and Sandia frequency shift for inverter-based distributed generations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azim, Riyasat; Li, Fangxing; Xue, Yaosuo

Distributed generations (DGs) for grid-connected applications require an accurate and reliable islanding detection methodology (IDM) for secure system operation. This paper presents an IDM for grid-connected inverter-based DGs. The proposed method is a combination of passive and active islanding detection techniques for aggregation of their advantages and elimination/minimisation of the drawbacks. In the proposed IDM, the passive method utilises critical system attributes extracted from local voltage measurements at target DG locations as well as employs decision tree-based classifiers for characterisation and detection of islanding events. The active method is based on Sandia frequency shift technique and is initiated only whenmore » the passive method is unable to differentiate islanding events from other system events. Thus, the power quality degradation introduced into the system by active islanding detection techniques can be minimised. Furthermore, a combination of active and passive techniques allows detection of islanding events under low power mismatch scenarios eliminating the disadvantage associated with the use of passive techniques alone. Finally, detailed case study results demonstrate the effectiveness of the proposed method in detection of islanding events under various power mismatch scenarios, load quality factors and in the presence of single or multiple grid-connected inverter-based DG units.« less

Modelling and control of a microgrid including photovoltaic and wind generation

NASA Astrophysics Data System (ADS)

Hussain, Mohammed Touseef

Extensive increase of distributed generation (DG) penetration and the existence of multiple DG units at distribution level have introduced the notion of micro-grid. This thesis develops a detailed non-linear and small-signal dynamic model of a microgrid that includes PV, wind and conventional small scale generation along with their power electronics interfaces and the filters. The models developed evaluate the amount of generation mix from various DGs for satisfactory steady state operation of the microgrid. In order to understand the interaction of the DGs on microgrid system initially two simpler configurations were considered. The first one consists of microalternator, PV and their electronics, and the second system consists of microalternator and wind system each connected to the power system grid. Nonlinear and linear state space model of each microgrid are developed. Small signal analysis showed that the large participation of PV/wind can drive the microgrid to the brink of unstable region without adequate control. Non-linear simulations are carried out to verify the results obtained through small-signal analysis. The role of the extent of generation mix of a composite microgrid consisting of wind, PV and conventional generation was investigated next. The findings of the smaller systems were verified through nonlinear and small signal modeling. A central supervisory capacitor energy storage controller interfaced through a STATCOM was proposed to monitor and enhance the microgrid operation. The potential of various control inputs to provide additional damping to the system has been evaluated through decomposition techniques. The signals identified to have damping contents were employed to design the supervisory control system. The controller gains were tuned through an optimal pole placement technique. Simulation studies demonstrate that the STATCOM voltage phase angle and PV inverter phase angle were the best inputs for enhanced stability boundaries.

Microscale air quality impacts of distributed power generation facilities.

PubMed

Olaguer, Eduardo P; Knipping, Eladio; Shaw, Stephanie; Ravindran, Satish

2016-08-01

The electric system is experiencing rapid growth in the adoption of a mix of distributed renewable and fossil fuel sources, along with increasing amounts of off-grid generation. New operational regimes may have unforeseen consequences for air quality. A three-dimensional microscale chemical transport model (CTM) driven by an urban wind model was used to assess gaseous air pollutant and particulate matter (PM) impacts within ~10 km of fossil-fueled distributed power generation (DG) facilities during the early afternoon of a typical summer day in Houston, TX. Three types of DG scenarios were considered in the presence of motor vehicle emissions and a realistic urban canopy: (1) a 25-MW natural gas turbine operating at steady state in either simple cycle or combined heating and power (CHP) mode; (2) a 25-MW simple cycle gas turbine undergoing a cold startup with either moderate or enhanced formaldehyde emissions; and (3) a data center generating 10 MW of emergency power with either diesel or natural gas-fired backup generators (BUGs) without pollution controls. Simulations of criteria pollutants (NO2, CO, O3, PM) and the toxic pollutant, formaldehyde (HCHO), were conducted assuming a 2-hr operational time period. In all cases, NOx titration dominated ozone production near the source. The turbine scenarios did not result in ambient concentration enhancements significantly exceeding 1 ppbv for gaseous pollutants or over 1 µg/m(3) for PM after 2 hr of emission, assuming realistic plume rise. In the case of the datacenter with diesel BUGs, ambient NO2 concentrations were enhanced by 10-50 ppbv within 2 km downwind of the source, while maximum PM impacts in the immediate vicinity of the datacenter were less than 5 µg/m(3). Plausible scenarios of distributed fossil generation consistent with the electricity grid's transformation to a more flexible and modernized system suggest that a substantial amount of deployment would be required to significantly affect air quality on a localized scale. In particular, natural gas turbines typically used in distributed generation may have minor effects. Large banks of diesel backup generators such as those used by data centers, on the other hand, may require pollution controls or conversion to natural gas-fired reciprocal internal combustion engines to decrease nitrogen dioxide pollution.

Performance Enhancement of Radial Distributed System with Distributed Generators by Reconfiguration Using Binary Firefly Algorithm

NASA Astrophysics Data System (ADS)

Rajalakshmi, N.; Padma Subramanian, D.; Thamizhavel, K.

2015-03-01

The extent of real power loss and voltage deviation associated with overloaded feeders in radial distribution system can be reduced by reconfiguration. Reconfiguration is normally achieved by changing the open/closed state of tie/sectionalizing switches. Finding optimal switch combination is a complicated problem as there are many switching combinations possible in a distribution system. Hence optimization techniques are finding greater importance in reducing the complexity of reconfiguration problem. This paper presents the application of firefly algorithm (FA) for optimal reconfiguration of radial distribution system with distributed generators (DG). The algorithm is tested on IEEE 33 bus system installed with DGs and the results are compared with binary genetic algorithm. It is found that binary FA is more effective than binary genetic algorithm in achieving real power loss reduction and improving voltage profile and hence enhancing the performance of radial distribution system. Results are found to be optimum when DGs are added to the test system, which proved the impact of DGs on distribution system.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doris, E.; Krasko, V.A.

State and local policymakers show increasing interest in spurring the development of customer-sited distributed generation (DG), in particular solar photovoltaic (PV) markets. Prompted by that interest, this analysis examines the use of state policy as a tool to support the development of a robust private investment market. This analysis builds on previous studies that focus on government subsidies to reduce installation costs of individual projects and provides an evaluation of the impacts of policies on stimulating private market development.

Gender differences and lateralization in the distribution pattern of insulin-like growth factor-1 receptor in developing rat hippocampus: an immunohistochemical study.

PubMed

Hami, Javad; Kheradmand, Hamed; Haghir, Hossein

2014-03-01

Numerous investigators have provided data supporting essential roles for insulin-like growth factor-I (IGF-I) in development of the brain. The aim of this study was to immunohistochemically determine the distinct regional distribution pattern of IGF-1 receptor (IGF-IR) expression in various portions of newborn rat hippocampus on postnatal days 0 (P0), 7 (P7), and 14 (P14), with comparison between male/female and right/left hippocampi. We found an overall significant increase in distribution of IGF-IR-positive (IGF-IR+) cells in CA1 from P0 until P14. Although, no marked changes in distribution of IGF-IR+ cells in areas CA2 and CA3 were observed; IGF-IR+ cells in DG decreased until P14. The smallest number of immunoreactive cells was present in CA2 and the highest number in DG at P0. Moreover, in CA1, CA3, and DG, the number of IGF-IR+ cells was markedly higher in both sides of the hippocampus in females. Our data also showed a higher mean number of IGF-IR+ cells in the left hippocampus of female at P7. By contrast, male pups showed a significantly higher number of IGF-IR+ cells in the DG of the right hippocampus. At P14, the mean number of immunoreactive cells in CA1, CA3, and DG areas found to be significantly increased in left side of hippocampus of males, compared to females. These results indicate the existence of a differential distribution pattern of IGF-IR between left-right and male-female hippocampi. Together with other mechanisms, these differences may underlie sexual dimorphism and left-right asymmetry in the hippocampus.

Energy and Cost Optimized Technology Options to Meet Energy Needs of Food Processors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makhmalbaf, Atefe; Srivastava, Viraj; Hoffman, Michael G.

ABSTRACT Combined cooling, heating and electric power (CCHP) distributed generation (DG) systems can provide electricity, heat, and cooling power to buildings and industrial processes directly onsite, while significantly increasing energy efficiency, security of energy supply, and grid independence. Fruit, vegetable, dairy and meat processing industries with simultaneous requirements for heat, steam, chilling and electricity, are well suited for the use of such systems to supply base-load electrical demand or as peak reducing generators with heat recovery in the forms of hot water, steam and/or chilled water. This paper documents results and analysis from a pilot project to evaluate opportunities formore » energy, emission, and cost for CCHP-DG and energy storage systems installed onsite at food processing facilities. It was found that a dairy processing plant purchasing 15,000 MWh of electricity will need to purchase 450 MWh with the integration of a 1.1 MW CCHP system. Here, the natural gas to be purchased increased from 190,000 MMBtu to 255,000 MMBtu given the fuel requirements of the CCHP system. CCHP systems lower emissions, however, in the Pacific Northwest the high percentage of hydro-power results in CO2 emissions from CCHP were higher than that attributed to the electric utility/regional energy mix. The value of this paper is in promoting and educating financial decision makers to seriously consider CCHP systems when building or upgrading facilities. The distributed generation aspect can reduce utility costs for industrial facilities and show non-wires solution benefits to delay or eliminate the need for upgrades to local electric transmission and distribution systems.« less

Analysis of critical operating conditions for LV distribution networks with microgrids

NASA Astrophysics Data System (ADS)

Zehir, M. A.; Batman, A.; Sonmez, M. A.; Font, A.; Tsiamitros, D.; Stimoniaris, D.; Kollatou, T.; Bagriyanik, M.; Ozdemir, A.; Dialynas, E.

2016-11-01

Increase in the penetration of Distributed Generation (DG) in distribution networks, raises the risk of voltage limit violations while contributing to line losses. Especially in low voltage (LV) distribution networks (secondary distribution networks), impacts of active power flows on the bus voltages and on the network losses are more dominant. As network operators must meet regulatory limitations, they have to take into account the most critical operating conditions in their systems. In this study, it is aimed to present the impact of the worst operation cases of LV distribution networks comprising microgrids. Simulation studies are performed on a field data-based virtual test-bed. The simulations are repeated for several cases consisting different microgrid points of connection with different network loading and microgrid supply/demand conditions.

Active and Reactive Power Optimal Dispatch Associated with Load and DG Uncertainties in Active Distribution Network

NASA Astrophysics Data System (ADS)

Gao, F.; Song, X. H.; Zhang, Y.; Li, J. F.; Zhao, S. S.; Ma, W. Q.; Jia, Z. Y.

2017-05-01

In order to reduce the adverse effects of uncertainty on optimal dispatch in active distribution network, an optimal dispatch model based on chance-constrained programming is proposed in this paper. In this model, the active and reactive power of DG can be dispatched at the aim of reducing the operating cost. The effect of operation strategy on the cost can be reflected in the objective which contains the cost of network loss, DG curtailment, DG reactive power ancillary service, and power quality compensation. At the same time, the probabilistic constraints can reflect the operation risk degree. Then the optimal dispatch model is simplified as a series of single stage model which can avoid large variable dimension and improve the convergence speed. And the single stage model is solved using a combination of particle swarm optimization (PSO) and point estimate method (PEM). Finally, the proposed optimal dispatch model and method is verified by the IEEE33 test system.

Commissioning dose computation models for spot scanning proton beams in water for a commercially available treatment planning system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, X. R.; Poenisch, F.; Lii, M.

2013-04-15

Purpose: To present our method and experience in commissioning dose models in water for spot scanning proton therapy in a commercial treatment planning system (TPS). Methods: The input data required by the TPS included in-air transverse profiles and integral depth doses (IDDs). All input data were obtained from Monte Carlo (MC) simulations that had been validated by measurements. MC-generated IDDs were converted to units of Gy mm{sup 2}/MU using the measured IDDs at a depth of 2 cm employing the largest commercially available parallel-plate ionization chamber. The sensitive area of the chamber was insufficient to fully encompass the entire lateralmore » dose deposited at depth by a pencil beam (spot). To correct for the detector size, correction factors as a function of proton energy were defined and determined using MC. The fluence of individual spots was initially modeled as a single Gaussian (SG) function and later as a double Gaussian (DG) function. The DG fluence model was introduced to account for the spot fluence due to contributions of large angle scattering from the devices within the scanning nozzle, especially from the spot profile monitor. To validate the DG fluence model, we compared calculations and measurements, including doses at the center of spread out Bragg peaks (SOBPs) as a function of nominal field size, range, and SOBP width, lateral dose profiles, and depth doses for different widths of SOBP. Dose models were validated extensively with patient treatment field-specific measurements. Results: We demonstrated that the DG fluence model is necessary for predicting the field size dependence of dose distributions. With this model, the calculated doses at the center of SOBPs as a function of nominal field size, range, and SOBP width, lateral dose profiles and depth doses for rectangular target volumes agreed well with respective measured values. With the DG fluence model for our scanning proton beam line, we successfully treated more than 500 patients from March 2010 through June 2012 with acceptable agreement between TPS calculated and measured dose distributions. However, the current dose model still has limitations in predicting field size dependence of doses at some intermediate depths of proton beams with high energies. Conclusions: We have commissioned a DG fluence model for clinical use. It is demonstrated that the DG fluence model is significantly more accurate than the SG fluence model. However, some deficiencies in modeling the low-dose envelope in the current dose algorithm still exist. Further improvements to the current dose algorithm are needed. The method presented here should be useful for commissioning pencil beam dose algorithms in new versions of TPS in the future.« less

Commissioning dose computation models for spot scanning proton beams in water for a commercially available treatment planning system

PubMed Central

Zhu, X. R.; Poenisch, F.; Lii, M.; Sawakuchi, G. O.; Titt, U.; Bues, M.; Song, X.; Zhang, X.; Li, Y.; Ciangaru, G.; Li, H.; Taylor, M. B.; Suzuki, K.; Mohan, R.; Gillin, M. T.; Sahoo, N.

2013-01-01

Purpose: To present our method and experience in commissioning dose models in water for spot scanning proton therapy in a commercial treatment planning system (TPS). Methods: The input data required by the TPS included in-air transverse profiles and integral depth doses (IDDs). All input data were obtained from Monte Carlo (MC) simulations that had been validated by measurements. MC-generated IDDs were converted to units of Gy mm2/MU using the measured IDDs at a depth of 2 cm employing the largest commercially available parallel-plate ionization chamber. The sensitive area of the chamber was insufficient to fully encompass the entire lateral dose deposited at depth by a pencil beam (spot). To correct for the detector size, correction factors as a function of proton energy were defined and determined using MC. The fluence of individual spots was initially modeled as a single Gaussian (SG) function and later as a double Gaussian (DG) function. The DG fluence model was introduced to account for the spot fluence due to contributions of large angle scattering from the devices within the scanning nozzle, especially from the spot profile monitor. To validate the DG fluence model, we compared calculations and measurements, including doses at the center of spread out Bragg peaks (SOBPs) as a function of nominal field size, range, and SOBP width, lateral dose profiles, and depth doses for different widths of SOBP. Dose models were validated extensively with patient treatment field-specific measurements. Results: We demonstrated that the DG fluence model is necessary for predicting the field size dependence of dose distributions. With this model, the calculated doses at the center of SOBPs as a function of nominal field size, range, and SOBP width, lateral dose profiles and depth doses for rectangular target volumes agreed well with respective measured values. With the DG fluence model for our scanning proton beam line, we successfully treated more than 500 patients from March 2010 through June 2012 with acceptable agreement between TPS calculated and measured dose distributions. However, the current dose model still has limitations in predicting field size dependence of doses at some intermediate depths of proton beams with high energies. Conclusions: We have commissioned a DG fluence model for clinical use. It is demonstrated that the DG fluence model is significantly more accurate than the SG fluence model. However, some deficiencies in modeling the low-dose envelope in the current dose algorithm still exist. Further improvements to the current dose algorithm are needed. The method presented here should be useful for commissioning pencil beam dose algorithms in new versions of TPS in the future. PMID:23556893

Commissioning dose computation models for spot scanning proton beams in water for a commercially available treatment planning system.

PubMed

Zhu, X R; Poenisch, F; Lii, M; Sawakuchi, G O; Titt, U; Bues, M; Song, X; Zhang, X; Li, Y; Ciangaru, G; Li, H; Taylor, M B; Suzuki, K; Mohan, R; Gillin, M T; Sahoo, N

2013-04-01

To present our method and experience in commissioning dose models in water for spot scanning proton therapy in a commercial treatment planning system (TPS). The input data required by the TPS included in-air transverse profiles and integral depth doses (IDDs). All input data were obtained from Monte Carlo (MC) simulations that had been validated by measurements. MC-generated IDDs were converted to units of Gy mm(2)/MU using the measured IDDs at a depth of 2 cm employing the largest commercially available parallel-plate ionization chamber. The sensitive area of the chamber was insufficient to fully encompass the entire lateral dose deposited at depth by a pencil beam (spot). To correct for the detector size, correction factors as a function of proton energy were defined and determined using MC. The fluence of individual spots was initially modeled as a single Gaussian (SG) function and later as a double Gaussian (DG) function. The DG fluence model was introduced to account for the spot fluence due to contributions of large angle scattering from the devices within the scanning nozzle, especially from the spot profile monitor. To validate the DG fluence model, we compared calculations and measurements, including doses at the center of spread out Bragg peaks (SOBPs) as a function of nominal field size, range, and SOBP width, lateral dose profiles, and depth doses for different widths of SOBP. Dose models were validated extensively with patient treatment field-specific measurements. We demonstrated that the DG fluence model is necessary for predicting the field size dependence of dose distributions. With this model, the calculated doses at the center of SOBPs as a function of nominal field size, range, and SOBP width, lateral dose profiles and depth doses for rectangular target volumes agreed well with respective measured values. With the DG fluence model for our scanning proton beam line, we successfully treated more than 500 patients from March 2010 through June 2012 with acceptable agreement between TPS calculated and measured dose distributions. However, the current dose model still has limitations in predicting field size dependence of doses at some intermediate depths of proton beams with high energies. We have commissioned a DG fluence model for clinical use. It is demonstrated that the DG fluence model is significantly more accurate than the SG fluence model. However, some deficiencies in modeling the low-dose envelope in the current dose algorithm still exist. Further improvements to the current dose algorithm are needed. The method presented here should be useful for commissioning pencil beam dose algorithms in new versions of TPS in the future.

IMEX HDG-DG: A coupled implicit hybridized discontinuous Galerkin and explicit discontinuous Galerkin approach for Euler systems on cubed sphere.

NASA Astrophysics Data System (ADS)

Kang, S.; Muralikrishnan, S.; Bui-Thanh, T.

2017-12-01

We propose IMEX HDG-DG schemes for Euler systems on cubed sphere. Of interest is subsonic flow, where the speed of the acoustic wave is faster than that of the nonlinear advection. In order to simulate these flows efficiently, we split the governing system into stiff part describing the fast waves and non-stiff part associated with nonlinear advection. The former is discretized implicitly with HDG method while explicit Runge-Kutta DG discretization is employed for the latter. The proposed IMEX HDG-DG framework: 1) facilitates high-order solution both in time and space; 2) avoids overly small time stepsizes; 3) requires only one linear system solve per time step; and 4) relatively to DG generates smaller and sparser linear system while promoting further parallelism owing to HDG discretization. Numerical results for various test cases demonstrate that our methods are comparable to explicit Runge-Kutta DG schemes in terms of accuracy, while allowing for much larger time stepsizes.

Evolving Distributed Generation Support Mechanisms: Case Studies from United States, Germany, United Kingdom, and Australia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lowder, Travis; Zhou, Ella; Tian, Tian

This report expands on a previous National Renewable Energy Laboratory (NREL) technical report (Lowder et al. 2015) that focused on the United States' unique approach to distributed generation photovoltaics (DGPV) support policies and business models. While the focus of that report was largely historical (i.e., detailing the policies and market developments that led to the growth of DGPV in the United States), this report looks forward, narrating recent changes to laws and regulations as well as the ongoing dialogues over how to incorporate distributed generation (DG) resources onto the electric grid. This report also broadens the scope of Lowder etmore » al. (2015) to include additional countries and technologies. DGPV and storage are the principal technologies under consideration (owing to market readiness and deployment volumes), but the report also contemplates any generation resource that is (1) on the customer side of the meter, (2) used to, at least partly, offset a host's energy consumption, and/or (3) potentially available to provide grid support (e.g., through peak shaving and load shifting, ancillary services, and other means).« less

Optimal coordinated voltage control in active distribution networks using backtracking search algorithm

PubMed Central

Tengku Hashim, Tengku Juhana; Mohamed, Azah

2017-01-01

The growing interest in distributed generation (DG) in recent years has led to a number of generators connected to a distribution system. The integration of DGs in a distribution system has resulted in a network known as active distribution network due to the existence of bidirectional power flow in the system. Voltage rise issue is one of the predominantly important technical issues to be addressed when DGs exist in an active distribution network. This paper presents the application of the backtracking search algorithm (BSA), which is relatively new optimisation technique to determine the optimal settings of coordinated voltage control in a distribution system. The coordinated voltage control considers power factor, on-load tap-changer and generation curtailment control to manage voltage rise issue. A multi-objective function is formulated to minimise total losses and voltage deviation in a distribution system. The proposed BSA is compared with that of particle swarm optimisation (PSO) so as to evaluate its effectiveness in determining the optimal settings of power factor, tap-changer and percentage active power generation to be curtailed. The load flow algorithm from MATPOWER is integrated in the MATLAB environment to solve the multi-objective optimisation problem. Both the BSA and PSO optimisation techniques have been tested on a radial 13-bus distribution system and the results show that the BSA performs better than PSO by providing better fitness value and convergence rate. PMID:28991919

Optimal coordinated voltage control in active distribution networks using backtracking search algorithm.

PubMed

Tengku Hashim, Tengku Juhana; Mohamed, Azah

2017-01-01

The growing interest in distributed generation (DG) in recent years has led to a number of generators connected to a distribution system. The integration of DGs in a distribution system has resulted in a network known as active distribution network due to the existence of bidirectional power flow in the system. Voltage rise issue is one of the predominantly important technical issues to be addressed when DGs exist in an active distribution network. This paper presents the application of the backtracking search algorithm (BSA), which is relatively new optimisation technique to determine the optimal settings of coordinated voltage control in a distribution system. The coordinated voltage control considers power factor, on-load tap-changer and generation curtailment control to manage voltage rise issue. A multi-objective function is formulated to minimise total losses and voltage deviation in a distribution system. The proposed BSA is compared with that of particle swarm optimisation (PSO) so as to evaluate its effectiveness in determining the optimal settings of power factor, tap-changer and percentage active power generation to be curtailed. The load flow algorithm from MATPOWER is integrated in the MATLAB environment to solve the multi-objective optimisation problem. Both the BSA and PSO optimisation techniques have been tested on a radial 13-bus distribution system and the results show that the BSA performs better than PSO by providing better fitness value and convergence rate.

Restraint Method of Voltage Total Harmonic Distortion in Distribution Network by Power Conditioner Systems using Measured Data from IT Switches

NASA Astrophysics Data System (ADS)

Kawasaki, Shoji; Shimoda, Kazuki; Tanaka, Motohiro; Taoka, Hisao; Matsuki, Junya; Hayashi, Yasuhiro

Recently, the amount of distributed generation (DG) such as photovoltaic system and wind power generator system installed in a distribution system has been increasing because of reduction of the effects on the environment. However, the harmonic troubles in the distribution system are apprehended in the background of the increase of connection of DGs through the inverters and the spread of power electronics equipment. In this paper, the authors propose a restraint method of voltage total harmonic distortion (THD) in a whole distribution network by active filter (AF) operation of plural power conditioner systems (PCS). Moreover, the authors propose a determination method of the optimal gain of AF operation so as to minimize the maximum value of voltage THD in the distribution network by the real-time feedback control with measured data from the information technology (IT) switches. In order to verify the validity of the proposed method, the numerical calculations are carried out by using an analytical model of distribution network interconnected DGs with PCS.

Analysis and Application of Microgrids

NASA Astrophysics Data System (ADS)

Yue, Lu

New trends of generating electricity locally and utilizing non-conventional or renewable energy sources have attracted increasing interests due to the gradual depletion of conventional fossil fuel energy sources. The new type of power generation is called Distributed Generation (DG) and the energy sources utilized by Distributed Generation are termed Distributed Energy Sources (DERs). With DGs embedded in the distribution networks, they evolve from passive distribution networks to active distribution networks enabling bidirectional power flows in the networks. Further incorporating flexible and intelligent controllers and employing future technologies, active distribution networks will turn to a Microgrid. A Microgrid is a small-scale, low voltage Combined with Heat and Power (CHP) supply network designed to supply electrical and heat loads for a small community. To further implement Microgrids, a sophisticated Microgrid Management System must be integrated. However, due to the fact that a Microgrid has multiple DERs integrated and is likely to be deregulated, the ability to perform real-time OPF and economic dispatch with fast speed advanced communication network is necessary. In this thesis, first, problems such as, power system modelling, power flow solving and power system optimization, are studied. Then, Distributed Generation and Microgrid are studied and reviewed, including a comprehensive review over current distributed generation technologies and Microgrid Management Systems, etc. Finally, a computer-based AC optimization method which minimizes the total transmission loss and generation cost of a Microgrid is proposed and a wireless communication scheme based on synchronized Code Division Multiple Access (sCDMA) is proposed. The algorithm is tested with a 6-bus power system and a 9-bus power system.

Foundational Report Series: Advanced Distribution Management Systems for Grid Modernization, DMS Integration of Distributed Energy Resources and Microgrids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Ravindra; Reilly, James T.; Wang, Jianhui

Deregulation of the electric utility industry, environmental concerns associated with traditional fossil fuel-based power plants, volatility of electric energy costs, Federal and State regulatory support of “green” energy, and rapid technological developments all support the growth of Distributed Energy Resources (DERs) in electric utility systems and ensure an important role for DERs in the smart grid and other aspects of modern utilities. DERs include distributed generation (DG) systems, such as renewables; controllable loads (also known as demand response); and energy storage systems. This report describes the role of aggregators of DERs in providing optimal services to distribution networks, through DERmore » monitoring and control systems—collectively referred to as a Distributed Energy Resource Management System (DERMS)—and microgrids in various configurations.« less

Non-Aqueous Titration Method for Determining Suppressor Concentration in the MCU Next Generation Solvent (NGS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor-Pashow, Kathryn M. L.; Jones, Daniel H.

A non-aqueous titration method has been used for quantifying the suppressor concentration in the MCU solvent hold tank (SHT) monthly samples since the Next Generation Solvent (NGS) was implemented in 2013. The titration method measures the concentration of the NGS suppressor (TiDG) as well as the residual tri-n-octylamine (TOA) that is a carryover from the previous solvent. As the TOA concentration has decreased over time, it has become difficult to resolve the TiDG equivalence point as the TOA equivalence point has moved closer. In recent samples, the TiDG equivalence point could not be resolved, and therefore, the TiDG concentration wasmore » determined by subtracting the TOA concentration as measured by semi-volatile organic analysis (SVOA) from the total base concentration as measured by titration. In order to improve the titration method so that the TiDG concentration can be measured directly, without the need for the SVOA data, a new method has been developed that involves spiking of the sample with additional TOA to further separate the two equivalence points in the titration. This method has been demonstrated on four recent SHT samples and comparison to results obtained using the SVOA TOA subtraction method shows good agreement. Therefore, it is recommended that the titration procedure be revised to include the TOA spike addition, and this to become the primary method for quantifying the TiDG.« less

Mean Glandular dose coefficients (DgN) for x-ray spectra used in contemporary breast imaging systems

PubMed Central

Nosratieh, Anita; Hernandez, Andrew; Shen, Sam Z.; Yaffe, Martin J.; Seibert, J. Anthony; Boone, John M.

2015-01-01

Purpose To develop tables of normalized glandular dose coefficients DgN for a range of anode–filter combinations and tube voltages used in contemporary breast imaging systems. Methods Previously published mono-energetic DgN values were used with various spectra to mathematically compute DgN coefficients. The tungsten anode spectra from TASMICS were used; Molybdenum and Rhodium anode-spectra were generated using MCNPx Monte Carlo code. The spectra were filtered with various thicknesses of Al, Rh, Mo or Cu. An initial HVL calculation was made using the anode and filter material. A range of the HVL values was produced with the addition of small thicknesses of polymethyl methacrylate (PMMA) as a surrogate for the breast compression paddle, to produce a range of HVL values at each tube voltage. Using a spectral weighting method, DgN coefficients for the generated spectra were calculated for breast glandular densities of 0%, 12.5%, 25%, 37.5%, 50% and 100% for a range of compressed breast thicknesses from 3 to 8 cm. Results Eleven tables of normalized glandular dose (DgN) coefficients were produced for the following anode/filter combinations: W + 50 μm Ag, W + 500 μm Al, W + 700 μm Al, W + 200 μm Cu, W + 300 μm Cu, W + 50 μm Rh, Mo + 400 μm Cu, Mo + 30 μm Mo, Mo + 25 μm Rh, Rh + 400 μm Cu and Rh + 25 μm Rh. Where possible, these results were compared to previously published DgN values and were found to be on average less than 2% different than previously reported values. Conclusion Over 200-pages of DgN coefficients were computed for modeled x-ray system spectra that are used in a number of new breast imaging applications. The reported values were found to be in excellent agreement when compared to published values. PMID:26348995

Impact of device engineering on analog/RF performances of tunnel field effect transistors

NASA Astrophysics Data System (ADS)

Vijayvargiya, V.; Reniwal, B. S.; Singh, P.; Vishvakarma, S. K.

2017-06-01

The tunnel field effect transistor (TFET) and its analog/RF performance is being aggressively studied at device architecture level for low power SoC design. Therefore, in this paper we have investigated the influence of the gate-drain underlap (UL) and different dielectric materials for the spacer and gate oxide on DG-TFET (double gate TFET) and its analog/RF performance for low power applications. Here, it is found that the drive current behavior in DG-TFET with a UL feature while implementing dielectric material for the spacer is different in comparison to that of DG-FET. Further, hetero gate dielectric-based DG-TFET (HGDG-TFET) is more resistive against drain-induced barrier lowering (DIBL) as compared to DG-TFET with high-k (HK) gate dielectric. Along with that, as compared to DG-FET, this paper also analyses the attributes of UL and dielectric material on analog/RF performance of DG-TFET in terms of transconductance (gm ), transconductance generation factor (TGF), capacitance, intrinsic resistance (Rdcr), cut-off frequency (F T), and maximum oscillation frequency (F max). The LK spacer-based HGDG-TFET with a gate-drain UL has the potential to improve the RF performance of device.

SU-F-BRD-08: A Novel Technique to Derive a Clinically-Acceptable Beam Model for Proton Pencil-Beam Scanning in a Commercial Treatment Planning System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scholey, J. E.; Lin, L.; Ainsley, C. G.

2015-06-15

Purpose: To evaluate the accuracy and limitations of a commercially-available treatment planning system’s (TPS’s) dose calculation algorithm for proton pencil-beam scanning (PBS) and present a novel technique to efficiently derive a clinically-acceptable beam model. Methods: In-air fluence profiles of PBS spots were modeled in the TPS alternately as single-(SG) and double-Gaussian (DG) functions, based on fits to commissioning data. Uniform-fluence, single-energy-layer square fields of various sizes and energies were calculated with both beam models and delivered to water. Dose was measured at several depths. Motivated by observed discrepancies in measured-versus-calculated dose comparisons, a third model was constructed based on double-Gaussianmore » parameters contrived through a novel technique developed to minimize these differences (DGC). Eleven cuboid-dose-distribution-shaped fields with varying range/modulation and field size were subsequently generated in the TPS, using each of the three beam models described, and delivered to water. Dose was measured at the middle of each spread-out Bragg peak. Results: For energies <160 MeV, the DG model fit square-field measurements to <2% at all depths, while the SG model could disagree by >6%. For energies >160 MeV, both SG and DG models fit square-field measurements to <1% at <4 cm depth, but could exceed 6% deeper. By comparison, disagreement with the DGC model was always <3%. For the cuboid plans, calculation-versus-measured percent dose differences exceeded 7% for the SG model, being larger for smaller fields. The DG model showed <3% disagreement for all field sizes in shorter-range beams, although >5% differences for smaller fields persisted in longer-range beams. In contrast, the DGC model predicted measurements to <2% for all beams. Conclusion: Neither the TPS’s SG nor DG models, employed as intended, are ideally suited for routine clinical use. However, via a novel technique to be presented, its DG model can be tuned judiciously to yield acceptable results.« less

SU-F-I-01: Normalized Mean Glandular Dose Values for Dedicated Breast CT Using Realistic Breast-Shaped Phantoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hernandez, A; Boone, J

Purpose: To estimate normalized mean glandular dose values for dedicated breast CT (DgN-CT) using breast CT-derived phantoms and compare to estimations using cylindrical phantoms. Methods: Segmented breast CT (bCT) volume data sets (N=219) were used to measure effective diameter profiles and were grouped into quintiles by volume. The profiles were averaged within each quintile to represent the range of breast sizes found clinically. These profiles were then used to generate five voxelized computational phantoms (V1, V2, V3, V4, V5 for the small to large phantom sizes, respectively), and loaded into the MCNP6 lattice geometry to simulate normalized mean glandular dosemore » coefficients (DgN-CT) using the system specifications of the Doheny-prototype bCT scanner in our laboratory. The DgN-CT coefficients derived from the bCT-derived breast-shaped phantoms were compared to those generated using a simpler cylindrical phantom using a constant volume, and the following constraints: (1) Length=1.5*radius; (2) radius determined at chest wall (Rcw), and (3) radius determined at the phantom center-of-mass (Rcm). Results: The change in Dg-NCT coefficients averaged across all phantom sizes, was - 0.5%, 19.8%, and 1.3%, for constraints 1–3, respectively. This suggests that the cylindrical assumption is a good approximation if the radius is taken at the breast center-of-mass, but using the radius at the chest wall results in an underestimation of the glandular dose. Conclusion: The DgN-CT coefficients for bCT-derived phantoms were compared against the assumption of a cylindrical phantom and proved to be essentially equivalent when the cylinder radius was set to r=1.5/L or Rcm. While this suggests that for dosimetry applications a patient’s breast can be approximated as a cylinder (if the correct radius is applied), this assumes a homogenous composition of breast tissue and the results may be different if the realistic heterogeneous distribution of glandular tissue is considered. Research reported in this paper was supported in part by the National Cancer Institute of the National Institutes of Health under award R01CA181081. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institue of Health.« less

Improved sensing characteristics of dual-gate transistor sensor using silicon nanowire arrays defined by nanoimprint lithography.

PubMed

Lim, Cheol-Min; Lee, In-Kyu; Lee, Ki Joong; Oh, Young Kyoung; Shin, Yong-Beom; Cho, Won-Ju

2017-01-01

This work describes the construction of a sensitive, stable, and label-free sensor based on a dual-gate field-effect transistor (DG FET), in which uniformly distributed and size-controlled silicon nanowire (SiNW) arrays by nanoimprint lithography act as conductor channels. Compared to previous DG FETs with a planar-type silicon channel layer, the constructed SiNW DG FETs exhibited superior electrical properties including a higher capacitive-coupling ratio of 18.0 and a lower off-state leakage current under high-temperature stress. In addition, while the conventional planar single-gate (SG) FET- and planar DG FET-based pH sensors showed the sensitivities of 56.7 mV/pH and 439.3 mV/pH, respectively, the SiNW DG FET-based pH sensors showed not only a higher sensitivity of 984.1 mV/pH, but also a lower drift rate of 0.8% for pH-sensitivity. This demonstrates that the SiNW DG FETs simultaneously achieve high sensitivity and stability, with significant potential for future biosensing applications.

Improved sensing characteristics of dual-gate transistor sensor using silicon nanowire arrays defined by nanoimprint lithography

NASA Astrophysics Data System (ADS)

Lim, Cheol-Min; Lee, In-Kyu; Lee, Ki Joong; Oh, Young Kyoung; Shin, Yong-Beom; Cho, Won-Ju

2017-12-01

This work describes the construction of a sensitive, stable, and label-free sensor based on a dual-gate field-effect transistor (DG FET), in which uniformly distributed and size-controlled silicon nanowire (SiNW) arrays by nanoimprint lithography act as conductor channels. Compared to previous DG FETs with a planar-type silicon channel layer, the constructed SiNW DG FETs exhibited superior electrical properties including a higher capacitive-coupling ratio of 18.0 and a lower off-state leakage current under high-temperature stress. In addition, while the conventional planar single-gate (SG) FET- and planar DG FET-based pH sensors showed the sensitivities of 56.7 mV/pH and 439.3 mV/pH, respectively, the SiNW DG FET-based pH sensors showed not only a higher sensitivity of 984.1 mV/pH, but also a lower drift rate of 0.8% for pH-sensitivity. This demonstrates that the SiNW DG FETs simultaneously achieve high sensitivity and stability, with significant potential for future biosensing applications.

An Operating Method Using Prediction of Photovoltaic Power for a Photovoltaic-Diesel Hybrid Power Generation System

NASA Astrophysics Data System (ADS)

Yamamoto, Shigehiro; Sumi, Kazuyoshi; Nishikawa, Eiichi; Hashimoto, Takeshi

This paper describes a novel operating method using prediction of photovoltaic (PV) power for a photovoltaic-diesel hybrid power generation system. The system is composed of a PV array, a storage battery, a bi-directional inverter and a diesel engine generator (DG). The proposed method enables the system to save fuel consumption by using PV energy effectively, reducing charge and discharge energy of the storage battery, and avoiding low-load operation of the DG. The PV power is simply predicted from a theoretical equation of solar radiation and the observed PV energy for a constant time before the prediction. The amount of fuel consumption of the proposed method is compared with that of other methods by a simulation based on measurement data of the PV power at an actual PV generation system for one year. The simulation results indicate that the amount of fuel consumption of the proposed method is smaller than that of any other methods, and is close to that of the ideal operation of the DG.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olama, Mohammed M; Allgood, Glenn O; Kuruganti, Phani Teja

Electric utilities have a main responsibility to protect the lives and safety of their workers when they are working on low-, medium-, and high-voltage power lines and distribution circuits. With the anticipated widespread deployment of smart grids, a secure and highly reliable means of maintaining isolation of customer-owned distributed generation (DG) from the affected distribution circuits during maintenance is necessary to provide a fully de-energized work area, ensure utility personnel safety, and prevent hazards that can lead to accidents such as accidental electrocution from unanticipated power sources. Some circuits are serviced while energized (live line work) while others are de-energizedmore » for maintenance. For servicing de-energized circuits and equipment, lock-out tag-out (LOTO) programs provide a verifiable procedure for ensuring that circuit breakers are locked in the off state and tagged to indicate that status to operational personnel so that the lines will be checked for voltage to verify they are de-energized. The de-energized area is isolated from any energized sources, which traditionally are the substations. This procedure works well when all power sources and their interconnections are known armed with this knowledge, utility personnel can determine the appropriate circuits to de-energize for isolating the target line or equipment. However, with customer-owned DG tied into the grid, the risk of inadvertently reenergizing a circuit increases because circuit connections may not be adequately documented and are not under the direct control of the local utility. Thus, the active device may not be properly de-energized or isolated from the work area. Further, a remote means of de-energizing and locking out energized devices provides an opportunity for greatly reduced safety risk to utility personnel compared to manual operations. In this paper, we present a remotely controllable LOTO system that allows individual workers to determine the configuration and status of electrical system circuits and permit them to lock out customer-owned DG devices for safety purposes using a highly secure and ultra-reliable radio signal. The system consists of: (1) individual personal lockout devices, (2) lockout communications and logic module at circuit breakers, which are located at all DG devices, and (3) a database and configuration control process located at the utility operations center. The lockout system is a close permissive, i.e., loss of control power or communications will cause the circuit breaker to open. Once the DG device is tripped open, a visual means will provide confirmation of a loss of voltage and current that verifies the disconnected status of the DG. Further the utility personnel will be able to place their own lock electronically on the system to ensure a lockout functionally. The proposed LOTO system provides enhanced worker safety and protection against unintended energized lines when DG is present. The main approaches and challenges encountered through designing the proposed region-wide LOTO system are discussed in this paper. These approaches include: (1) evaluating the reliability of the proposed approach under N-modular redundancy with voter/spares configurations and (2) conducting a system level risk assessment study using the failure modes and effects analysis (FMEA) technique to identify and rank failure modes by probability of occurrence, probability of detection, and severity of consequences. This ranking allows a cost benefits analysis to be conducted such that dollars and efforts will be applied to the failures that provide greatest incremental gains in system capability (resilience, survivability, security, reliability, availability, etc.) per dollar spent whether capital, operations, or investment. Several simulation scenarios and their results are presented to demonstrate the viability of these approaches.« less

Observations of jets from low-luminosity stars - DG Tauri B

NASA Technical Reports Server (NTRS)

Jones, B. F.; Cohen, Martin

1986-01-01

Low spectral resolution studies of DG Tau B, the faint system of knots south of the T Tauri star DG Tau, are described. The observations show this object to be bipolar, with the blueshifted lobe having extraordinarily low excitation. Infrared observations of the exciting star show it to be of very low luminosity, with a bolometric luminosity of 0.88 solar luminosity. The visual extinction indicates a highly nonspherical distribution of circumstellar dust around the exciting star. In spite of this lack of embedding within an obvious dark cloud, the system is identified as a young one.

Impacts of Demand-Side Resources on Electric Transmission Planning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hadley, Stanton W.; Sanstad, Alan H.

2015-01-01

Will demand resources such as energy efficiency (EE), demand response (DR), and distributed generation (DG) have an impact on electricity transmission requirements? Five drivers for transmission expansion are discussed: interconnection, reliability, economics, replacement, and policy. With that background, we review the results of a set of transmission studies that were conducted between 2010 and 2013 by electricity regulators, industry representatives, and other stakeholders in the three physical interconnections within the United States. These broad-based studies were funded by the US Department of Energy and included scenarios of reduced load growth due to EE, DR, and DG. While the studies weremore » independent and used different modeling tools and interconnect-specific assumptions, all provided valuable results and insights. However, some caveats exist. Demand resources were evaluated in conjunction with other factors, and limitations on transmission additions between scenarios made understanding the role of demand resources difficult. One study, the western study, included analyses over both 10- and 20-year planning horizons; the 10-year analysis did not show near-term reductions in transmission, but the 20-year indicated fewer transmission additions, yielding a 36percent capital cost reduction. In the eastern study the reductions in demand largely led to reductions in local generation capacity and an increased opportunity for low-cost and renewable generation to export to other regions. The Texas study evaluated generation changes due to demand, and is in the process of examining demand resource impacts on transmission.« less

PAMAM dendrimers as a carbamazepine delivery system for neurodegenerative diseases: A biophysical and nanotoxicological characterization.

PubMed

Igartúa, Daniela E; Martinez, Carolina S; Temprana, C Facundo; Alonso, Silvia Del V; Prieto, M Jimena

2018-06-10

Carbamazepine (CBZ) is an antiepileptic drug, which also could be used in the treatment of neurodegenerative diseases, such as the Alzheimer's disease. However, its use has been limited due to its low solubility, inefficient pharmacokinetic profiles, and multiple side effects. PAMAM dendrimers, ethylenediamine core, generation 4.0 (amine terminal groups) and 4.5 (carboxylate terminal groups) (DG4.0 and DG4.5 respectively) are polymers that can increase drug solubility through complexation. Thus, the aim of this work was to obtain and characterize complexes between CBZ and dendrimers. Both DG4.0 and DG4.5 allowed the incorporation of ∼20 molecules of CBZ per dendrimer, into their hydrophobic pockets. DG4.0-CBZ and DG4.5-CBZ complexes were found to be stable for 90 days at 37 °C and resistant to a lyophilization process, presenting controlled drug release. Also, the complexes nanotoxicity was tested ex vivo (human red blood cells), in vitro (N2a cell line), and in vivo (zebrafish). No hemolytic effect was observed in the ex vivo model. As regards in vitro toxicity, the DG4.5-CBZ complexes significantly reduced the toxicity caused by the free drug. Moreover, the DG4.5-CBZ did not cause neurotoxicity or cardiotoxicity in zebrafish larvae. In conclusion, a stable and biocompatible drug delivery system based on the DG4.5 capable of complex the CBZ has been developed. This achievement highlights the advantages of using negatively charged dendrimers for nanomedicine. Copyright © 2018 Elsevier B.V. All rights reserved.

Application of Phasor Measurement Units for Protection of Distribution Networks with High Penetration of Photovoltaic Sources

NASA Astrophysics Data System (ADS)

Meskin, Matin

The rate of the integration of distributed generation (DG) units to the distribution level to meet the growth in demand increases as a reasonable replacement for costly network expansion. This integration brings many advantages to the consumers and power grids, as well as giving rise to more challenges in relation to protection and control. Recent research has brought to light the negative effects of DG units on short circuit currents and overcurrent (OC) protection systems in distribution networks. Change in the direction of fault current flow, increment or decrement of fault current magnitude, blindness of protection, feeder sympathy trip, nuisance trip of interrupting devices, and the disruption of coordination between protective devices are some potential impacts of DG unit integration. Among other types of DG units, the integration of renewable energy resources into the electric grid has seen a vast improvement in recent years. In particular, the interconnection of photovoltaic (PV) sources to the medium voltage (MV) distribution networks has experienced a rapid increase in the last decade. In this work, the effect of PV source on conventional OC relays in MV distribution networks is shown. It is indicated that the PV output fluctuation, due to changes in solar radiation, causes the magnitude and direction of the current to change haphazardly. These variations may result in the poor operation of OC relays as the main protective devices in the MV distribution networks. In other words, due to the bi-directional power flow characteristic and the fluctuation of current magnitude occurring in the presence of PV sources, a specific setting of OC relays is difficult to realize. Therefore, OC relays may operate in normal conditions. To improve the OC relay operation, a voltage-dependent-overcurrent protection is proposed. Although, this new method prevents the OC relay from maloperation, its ability to detect earth faults and high impedance faults is poor. Thus, a comprehensive protective system is suggested at the end of the dissertation. The proposed method is based on the application of the phasor measurement unit (PMU) and the differential protection method. All of the current magnitudes and angles are collected by PMU and are sent to the phasor data concentrator (PDC), where a differential protection algorithm is applied to these data. If any fault is detected, the trip will be sent back to the corresponding circuit breakers across the network. Higher selectivity, sensitivity, and faster operation in the differential protection are superior to those of other protection schemes. Differential protection operates as unit protection, which means that it operates only when there is a fault in the protection zone. It does not function for faults occurring out of zone. Therefore, no coordination is required between differential protections across the power system. Moreover, the misoperation of this protective scheme is less likely as compared to other protection methods.

Evolving Distributed Generation Support Mechanisms: Case Studies from United States, Germany, United Kingdom, and Australia (Chinese translation)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Shengru; Lowder, Travis R; Tian, Tian

This is the Chinese translation of NREL/TP-6A20-67613. This report expands on a previous National Renewable Energy Laboratory (NREL) technical report (Lowder et al. 2015) that focused on the United States' unique approach to distributed generation photovoltaics (DGPV) support policies and business models. While the focus of that report was largely historical (i.e., detailing the policies and market developments that led to the growth of DGPV in the United States), this report looks forward, narrating recent changes to laws and regulations as well as the ongoing dialogues over how to incorporate distributed generation (DG) resources onto the electric grid. This reportmore » also broadens the scope of Lowder et al. (2015) to include additional countries and technologies. DGPV and storage are the principal technologies under consideration (owing to market readiness and deployment volumes), but the report also contemplates any generation resource that is (1) on the customer side of the meter, (2) used to, at least partly, offset a host's energy consumption, and/or (3) potentially available to provide grid support (e.g., through peak shaving and load shifting, ancillary services, and other means).« less

Improving Fidelity of Launch Vehicle Liftoff Acoustic Simulations

NASA Technical Reports Server (NTRS)

Liever, Peter; West, Jeff

2016-01-01

Launch vehicles experience high acoustic loads during ignition and liftoff affected by the interaction of rocket plume generated acoustic waves with launch pad structures. Application of highly parallelized Computational Fluid Dynamics (CFD) analysis tools optimized for application on the NAS computer systems such as the Loci/CHEM program now enable simulation of time-accurate, turbulent, multi-species plume formation and interaction with launch pad geometry and capture the generation of acoustic noise at the source regions in the plume shear layers and impingement regions. These CFD solvers are robust in capturing the acoustic fluctuations, but they are too dissipative to accurately resolve the propagation of the acoustic waves throughout the launch environment domain along the vehicle. A hybrid Computational Fluid Dynamics and Computational Aero-Acoustics (CFD/CAA) modeling framework has been developed to improve such liftoff acoustic environment predictions. The framework combines the existing highly-scalable NASA production CFD code, Loci/CHEM, with a high-order accurate discontinuous Galerkin (DG) solver, Loci/THRUST, developed in the same computational framework. Loci/THRUST employs a low dissipation, high-order, unstructured DG method to accurately propagate acoustic waves away from the source regions across large distances. The DG solver is currently capable of solving up to 4th order solutions for non-linear, conservative acoustic field propagation. Higher order boundary conditions are implemented to accurately model the reflection and refraction of acoustic waves on launch pad components. The DG solver accepts generalized unstructured meshes, enabling efficient application of common mesh generation tools for CHEM and THRUST simulations. The DG solution is coupled with the CFD solution at interface boundaries placed near the CFD acoustic source regions. Both simulations are executed simultaneously with coordinated boundary condition data exchange.

DGs for Service Restoration to Critical Loads in a Secondary Network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Yin; Liu, Chen-Ching; Wang, Zhiwen

During a major outage in a secondary network distribution system, distributed generators (DGs) connected to the primary feeders as well as the secondary network can be used to serve critical loads. This paper proposed a resilience-oriented method to determine restoration strategies for secondary network distribution systems after a major disaster. Technical issues associated with the restoration process are analyzed, including the operation of network protectors, inrush currents caused by the energization of network transformers, synchronization of DGs to the network, and circulating currents among DGs. A look-ahead load restoration framework is proposed, incorporating technical issues associated with secondary networks, limitsmore » on DG capacity and generation resources, dynamic constraints, and operational limits. The entire outage duration is divided into a sequence of periods. Restoration strategies can be adjusted at the beginning of each period using the latest information. Finally, numerical simulation of the modified IEEE 342-node low voltage networked test system is performed to validate the effectiveness of the proposed method.« less

DGs for Service Restoration to Critical Loads in a Secondary Network

DOE PAGES

Xu, Yin; Liu, Chen-Ching; Wang, Zhiwen; ...

2017-08-25

During a major outage in a secondary network distribution system, distributed generators (DGs) connected to the primary feeders as well as the secondary network can be used to serve critical loads. This paper proposed a resilience-oriented method to determine restoration strategies for secondary network distribution systems after a major disaster. Technical issues associated with the restoration process are analyzed, including the operation of network protectors, inrush currents caused by the energization of network transformers, synchronization of DGs to the network, and circulating currents among DGs. A look-ahead load restoration framework is proposed, incorporating technical issues associated with secondary networks, limitsmore » on DG capacity and generation resources, dynamic constraints, and operational limits. The entire outage duration is divided into a sequence of periods. Restoration strategies can be adjusted at the beginning of each period using the latest information. Finally, numerical simulation of the modified IEEE 342-node low voltage networked test system is performed to validate the effectiveness of the proposed method.« less

Glandular radiation dose in tomosynthesis of the breast using tungsten targets.

PubMed

Sechopoulos, Ioannis; D'Orsi, Carl J

2008-10-24

With the advent of new detector technology, digital tomosynthesis imaging of the breast has, in the past few years, become a technique intensely investigated as a replacement for planar mammography. As with all other x-ray-based imaging methods, radiation dose is of utmost concern in the development of this new imaging technology. For virtually all development and optimization studies, knowledge of the radiation dose involved in an imaging protocol is necessary. A previous study characterized the normalized glandular dose in tomosynthesis imaging and its variation with various breast and imaging system parameters. This characterization was performed with x-ray spectra generated by molybdenum and rhodium targets. In the recent past, many preliminary patient studies of tomosynthesis imaging have been reported in which the x-ray spectra were generated with x-ray tubes with tungsten targets. The differences in x-ray distribution among spectra from these target materials make the computation of new normalized glandular dose values for tungsten target spectra necessary. In this study we used previously obtained monochromatic normalized glandular dose results to obtain spectral results for twelve different tungsten target x-ray spectra. For each imaging condition, two separate values were computed: the normalized glandular dose for the zero degree projection angle (DgN0), and the ratio of the glandular dose for non-zero projection angles to the glandular dose for the zero degree projection (the relative glandular dose, RGD(alpha)). It was found that DgN0 is higher for tungsten target x-ray spectra when compared with DgN0 values for molybdenum and rhodium target spectra of both equivalent tube voltage and first half value layer. Therefore, the DgN0 for the twelve tungsten target x-ray spectra and different breast compositions and compressed breast thicknesses simulated are reported. The RGD(alpha) values for the tungsten spectra vary with the parameters studied in a similar manner to that found for the molybdenum and rhodium target spectra. The surface fit equations and the fit coefficients for RGD(alpha) included in the previous study were also found to be appropriate for the tungsten spectra.

Antitumor effect of degalactosylated gc-globulin on orthotopic grafted lung cancer in mice.

PubMed

Hirota, Keiji; Nakagawa, Yoshinori; Takeuchi, Ryota; Uto, Yoshihiro; Hori, Hitoshi; Onizuka, Shinya; Terada, Hiroshi

2013-07-01

Group-specific component (Gc)-globulin-derived macrophage-activating factor (GcMAF) generated by a cascade of catalytic reactions with deglycosidase enzymes exerts antitumor activity. We hypothesized that degalactosyl Gc-globulin (DG3), a precursor of GcMAF, also plays a role in recovery from cancer as well as GcMAF due to progression of deglycosylation by generally resident sialidases and mannosidases. We prepared the subtypes of DG3, such as 1f1f and 1s1s and its 22 homodimers, by using vitamin D3-binding Sepharose CL-6B and examined their antitumor activity in mice bearing Lewis lung carcinoma cells, by counting the number of nodules formed in their lungs. Antitumor activity of DG3 was observed regardless of its subtype, being equivalent to that of GcMAF. The injection route of DG3 affected its antitumor activity, with subcutaneous and intramuscular administration being more favorable than the intraperitoneal or intravenous route. In order to obtain significant antitumor activity, more than 160 ng/kg of DG3 were required. DG3 proved to be promising as an antitumor agent, similarly to GcMAF.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Magee, Thoman

The Consolidated Edison, Inc., of New York (Con Edison) Secure Interoperable Open Smart Grid Demonstration Project (SGDP), sponsored by the United States (US) Department of Energy (DOE), demonstrated that the reliability, efficiency, and flexibility of the grid can be improved through a combination of enhanced monitoring and control capabilities using systems and resources that interoperate within a secure services framework. The project demonstrated the capability to shift, balance, and reduce load where and when needed in response to system contingencies or emergencies by leveraging controllable field assets. The range of field assets includes curtailable customer loads, distributed generation (DG), batterymore » storage, electric vehicle (EV) charging stations, building management systems (BMS), home area networks (HANs), high-voltage monitoring, and advanced metering infrastructure (AMI). The SGDP enables the seamless integration and control of these field assets through a common, cyber-secure, interoperable control platform, which integrates a number of existing legacy control and data systems, as well as new smart grid (SG) systems and applications. By integrating advanced technologies for monitoring and control, the SGDP helps target and reduce peak load growth, improves the reliability and efficiency of Con Edison’s grid, and increases the ability to accommodate the growing use of distributed resources. Con Edison is dedicated to lowering costs, improving reliability and customer service, and reducing its impact on the environment for its customers. These objectives also align with the policy objectives of New York State as a whole. To help meet these objectives, Con Edison’s long-term vision for the distribution grid relies on the successful integration and control of a growing penetration of distributed resources, including demand response (DR) resources, battery storage units, and DG. For example, Con Edison is expecting significant long-term growth of DG. The SGDP enables the efficient, flexible integration of these disparate resources and lays the architectural foundations for future scalability. Con Edison assembled an SGDP team of more than 16 different project partners, including technology vendors, and participating organizations, and the Con Edison team provided overall guidance and project management. Project team members are listed in Table 1-1.« less

A consortium approach to commercialized Westinghouse solid oxide fuel cell technology

NASA Astrophysics Data System (ADS)

Casanova, Allan

Westinghouse is developing its tubular solid oxide fuel cells (SOFCs) for a variety of applications in stationary power generation markets. By pressurizing a SOFC and integrating it with a gas turbine (GT), power systems with efficiencies as high as 70-75% can be obtained. The first such system will be tested in 1998. Because of their extraordinarily high efficiency (60-70%) even in small sizes the first SOFC products to be offered are expected to be integrated SOFC/GT power systems in the 1-7 MW range, for use in the emerging distributed generation (DG) market segment. Expansion into larger sizes will follow later. Because of their modularity, environmental friendliness and expected cost effectiveness, and because of a worldwide thrust towards utility deregulation, a ready market is forecasted for baseload distributed generation. Assuming Westinghouse can complete its technology development and reach its cost targets, the integrated SOFC/GT power system is seen as a product with tremendous potential in the emerging distributed generation market. While Westinghouse has been a leader in the development of power generation technology for over a century, it does not plan to manufacture small gas turbines. However, GTs small enough to integrate with SOFCs and address the 1-7 MW market are generally available from various manufacturers. Westinghouse will need access to a new set of customers as it brings baseload plants to the present small market mix of emergency and peaking power applications. Small cogeneration applications, already strong in some parts of the world, are also gaining ground everywhere. Small GT manufacturers already serve this market, and alliances and partnerships can enhance SOFC commercialization. Utilities also serve the DG market, especially those that have set up energy service companies and seek to grow beyond the legal and geographical confines of their current regulated business. Because fuel cells in general are a new product, because small baseload applications are a new segment, and because deregulation will continue to shake up the mature traditional power generation market, the commercial risks of launching a new product at this time are unique and considerable. Hence, a collaborative approach to commercialization is deemed desirable and appropriate, and collaboration with GT manufacturers and utilities will be addressed in this paper.

Energy metabolism of leukemia cells: glycolysis versus oxidative phosphorylation.

PubMed

Suganuma, Kazuto; Miwa, Hiroshi; Imai, Norikazu; Shikami, Masato; Gotou, Mayuko; Goto, Mineaki; Mizuno, Shohei; Takahashi, Miyuki; Yamamoto, Hidesuke; Hiramatsu, Akihito; Wakabayashi, Motohiro; Watarai, Masaya; Hanamura, Ichiro; Imamura, Akira; Mihara, Hidetsugu; Nitta, Masakazu

2010-11-01

For generation of energy, cancer cells utilize glycolysis more vigorously than oxidative phosphorylation in mitochondria (Warburg effect). We examined the energy metabolism of four leukemia cell lines by using glycolysis inhibitor, 2-deoxy-d-glucose (2-DG) and inhibitor of oxidative phosphorylation, oligomycin. NB4 was relatively sensitive to 2-DG (IC(50): 5.75 mM), consumed more glucose and produced more lactate (waste product of glycolysis) than the three other cell lines. Consequently, NB4 was considered as a "glycolytic" leukemia cell line. Dependency on glycolysis in NB4 was confirmed by the fact that glucose (+) FCS (-) medium showed more growth and survival than glucose (-) FCS (+) medium. Alternatively, THP-1, most resistant to 2-DG (IC(50): 16.14 mM), was most sensitive to oligomycin. Thus, THP-1 was recognized to be dependent on oxidative phosphorylation. In THP-1, glucose (-) FCS (+) medium showed more growth and survival than glucose (+) FCS (-) medium. The dependency of THP-1 on FCS was explained, at least partly, by fatty acid oxidation because inhibitor of fatty acid β-oxidation, etomoxir, augmented the growth suppression of THP-1 by 2-DG. We also examined the mechanisms by which THP-1 was resistant to, and NB4 was sensitive to 2-DG treatment. In THP-1, AMP kinase (AMPK), which is activated when ATP becomes limiting, was rapidly phosphorylated by 2-DG, and expression of Bcl-2 was augmented, which might result in resistance to 2-DG. On the other hand, AMPK phosphorylation and augmentation of Bcl-2 expression by 2-DG were not observed in NB4, which is 2-DG sensitive. These results will facilitate the future leukemia therapy targeting metabolic pathways.

Decentralized Energy Management System for Networked Microgrids in Grid-connected and Islanded Modes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhaoyu; Chen, Bokan; Wang, Jianhui

This paper proposes a decentralized energy management system (EMS) for the coordinated operation of networked Microgirds (MGs) in a distribution system. In the grid-connected mode, the distribution network operator (DNO) and each MG are considered as distinct entities with individual objectives to minimize their own operation costs. It is assumed that both dispatchable and renewable energy source (RES)-based distributed generators (DGs) exist in the distribution network and the networked MGs. In order to coordinate the operation of all entities, we apply a decentralized bi-level algorithm to solve the problem with the first level to conduct negotiations among all entities andmore » the second level to update the non-converging penalties. In the islanded mode, the objective of each MG is to maintain a reliable power supply to its customers. In order to take into account the uncertainties of DG outputs and load consumption, we formulate the problems as two-stage stochastic programs. The first stage is to determine base generation setpoints based on the forecasts and the second stage is to adjust the generation outputs based on the realized scenarios. Case studies of a distribution system with networked MGs demonstrate the effectiveness of the proposed methodology in both grid-connected and islanded modes.« less

Insights from Molecular Dynamics Simulations: Structural Basis for the V567D Mutation-Induced Instability of Zebrafish Alpha-Dystroglycan and Comparison with the Murine Model

PubMed Central

Pirolli, Davide; Sciandra, Francesca; Bozzi, Manuela; Giardina, Bruno; Brancaccio, Andrea; De Rosa, Maria Cristina

2014-01-01

A missense amino acid mutation of valine to aspartic acid in 567 position of alpha-dystroglycan (DG), identified in dag1-mutated zebrafish, results in a reduced transcription and a complete absence of the protein. Lacking experimental structural data for zebrafish DG domains, the detailed mechanism for the observed mutation-induced destabilization of the DG complex and membrane damage, remained unclear. With the aim to contribute to a better clarification of the structure-function relationships featuring the DG complex, three-dimensional structural models of wild-type and mutant (V567D) C-terminal domain of alpha-DG from zebrafish were constructed by a template-based modelling approach. We then ran extensive molecular dynamics (MD) simulations to reveal the structural and dynamic properties of the C-terminal domain and to evaluate the effect of the single mutation on alpha-DG stability. A comparative study has been also carried out on our previously generated model of murine alpha-DG C-terminal domain including the I591D mutation, which is topologically equivalent to the V567D mutation found in zebrafish. Trajectories from MD simulations were analyzed in detail, revealing extensive structural disorder involving multiple beta-strands in the mutated variant of the zebrafish protein whereas local effects have been detected in the murine protein. A biochemical analysis of the murine alpha-DG mutant I591D confirmed a pronounced instability of the protein. Taken together, the computational and biochemical analysis suggest that the V567D/I591D mutation, belonging to the G beta-strand, plays a key role in inducing a destabilization of the alpha-DG C-terminal Ig-like domain that could possibly affect and propagate to the entire DG complex. The structural features herein identified may be of crucial help to understand the molecular basis of primary dystroglycanopathies. PMID:25078606

Insights from molecular dynamics simulations: structural basis for the V567D mutation-induced instability of zebrafish alpha-dystroglycan and comparison with the murine model.

PubMed

Pirolli, Davide; Sciandra, Francesca; Bozzi, Manuela; Giardina, Bruno; Brancaccio, Andrea; De Rosa, Maria Cristina

2014-01-01

A missense amino acid mutation of valine to aspartic acid in 567 position of alpha-dystroglycan (DG), identified in dag1-mutated zebrafish, results in a reduced transcription and a complete absence of the protein. Lacking experimental structural data for zebrafish DG domains, the detailed mechanism for the observed mutation-induced destabilization of the DG complex and membrane damage, remained unclear. With the aim to contribute to a better clarification of the structure-function relationships featuring the DG complex, three-dimensional structural models of wild-type and mutant (V567D) C-terminal domain of alpha-DG from zebrafish were constructed by a template-based modelling approach. We then ran extensive molecular dynamics (MD) simulations to reveal the structural and dynamic properties of the C-terminal domain and to evaluate the effect of the single mutation on alpha-DG stability. A comparative study has been also carried out on our previously generated model of murine alpha-DG C-terminal domain including the I591D mutation, which is topologically equivalent to the V567D mutation found in zebrafish. Trajectories from MD simulations were analyzed in detail, revealing extensive structural disorder involving multiple beta-strands in the mutated variant of the zebrafish protein whereas local effects have been detected in the murine protein. A biochemical analysis of the murine alpha-DG mutant I591D confirmed a pronounced instability of the protein. Taken together, the computational and biochemical analysis suggest that the V567D/I591D mutation, belonging to the G beta-strand, plays a key role in inducing a destabilization of the alpha-DG C-terminal Ig-like domain that could possibly affect and propagate to the entire DG complex. The structural features herein identified may be of crucial help to understand the molecular basis of primary dystroglycanopathies.

Infiltration of chitin by protein coacervates defines the squid beak mechanical gradient.

PubMed

Tan, YerPeng; Hoon, Shawn; Guerette, Paul A; Wei, Wei; Ghadban, Ali; Hao, Cai; Miserez, Ali; Waite, J Herbert

2015-07-01

The beak of the jumbo squid Dosidicus gigas is a fascinating example of how seamlessly nature builds with mechanically mismatched materials. A 200-fold stiffness gradient begins in the hydrated chitin of the soft beak base and gradually increases to maximum stiffness in the dehydrated distal rostrum. Here, we combined RNA-Seq and proteomics to show that the beak contains two protein families. One family consists of chitin-binding proteins (DgCBPs) that physically join chitin chains, whereas the other family comprises highly modular histidine-rich proteins (DgHBPs). We propose that DgHBPs play multiple key roles during beak bioprocessing, first by forming concentrated coacervate solutions that diffuse into the DgCBP-chitin scaffold, and second by inducing crosslinking via an abundant GHG sequence motif. These processes generate spatially controlled desolvation, resulting in the impressive biomechanical gradient. Our findings provide novel molecular-scale strategies for designing functional gradient materials.

The Performance Analysis of a Uav Based Mobile Mapping System Platform

NASA Astrophysics Data System (ADS)

Tsai, M. L.; Chiang, K. W.; Lo, C. F.; Ch, C. H.

2013-08-01

To facilitate applications such as environment detection or disaster monitoring, the development of rapid low cost systems for collecting near real-time spatial information is very critical. Rapid spatial information collection has become an emerging trend for remote sensing and mapping applications. This study develops a Direct Georeferencing (DG) based fixed-wing Unmanned Aerial Vehicle (UAV) photogrammetric platform where an Inertial Navigation System (INS)/Global Positioning System (GPS) integrated Positioning and Orientation System (POS) system is implemented to provide the DG capability of the platform. The performance verification indicates that the proposed platform can capture aerial images successfully. A flight test is performed to verify the positioning accuracy in DG mode without using Ground Control Points (GCP). The preliminary results illustrate that horizontal DG positioning accuracies in the x and y axes are around 5 m with 300 m flight height. The positioning accuracy in the z axis is less than 10 m. Such accuracy is good for near real-time disaster relief. The DG ready function of proposed platform guarantees mapping and positioning capability even in GCP free environments, which is very important for rapid urgent response for disaster relief. Generally speaking, the data processing time for the DG module, including POS solution generalization, interpolation, Exterior Orientation Parameters (EOP) generation, and feature point measurements, is less than one hour.

Endogenous formation and repair of oxidatively induced G[8-5 m]T intrastrand cross-link lesion

PubMed Central

Wang, Jin; Cao, Huachuan; You, Changjun; Yuan, Bifeng; Bahde, Ralf; Gupta, Sanjeev; Nishigori, Chikako; Niedernhofer, Laura J.; Brooks, Philip J.; Wang, Yinsheng

2012-01-01

Exposure to reactive oxygen species (ROS) can give rise to the formation of various DNA damage products. Among them, d(G[8-5 m]T) can be induced in isolated DNA treated with Fenton reagents and in cultured human cells exposed to γ-rays, d(G[8-5m]T) can be recognized and incised by purified Escherichia coli UvrABC nuclease. However, it remains unexplored whether d(G[8-5 m]T) accumulates in mammalian tissues and whether it is a substrate for nucleotide excision repair (NER) in vivo. Here, we found that d(G[8-5 m]T) could be detected in DNA isolated from tissues of healthy humans and animals, and elevated endogenous ROS generation enhanced the accumulation of this lesion in tissues of a rat model of Wilson’s disease. Additionally, XPA-deficient human brain and mouse liver as well as various types of tissues of ERCC1-deficient mice contained higher levels of d(G[8-5 m]T) but not ROS-induced single-nucleobase lesions than the corresponding normal controls. Together, our studies established that d(G[8-5 m]T) can be induced endogenously in mammalian tissues and constitutes a substrate for NER in vivo. PMID:22581771

Muscle force distribution of the lower limbs during walking in diabetic individuals with and without polyneuropathy.

PubMed

Gomes, Aline A; Ackermann, Marko; Ferreira, Jean P; Orselli, Maria Isabel V; Sacco, Isabel C N

2017-11-09

Muscle force estimation could advance the comprehension of the neuromuscular strategies that diabetic patients adopt to preserve walking ability, which guarantees their independence as they deal with their neural and muscular impairments due to diabetes and neuropathy. In this study, the lower limb's muscle force distribution during gait was estimated and compared in diabetic patients with and without polyneuropathy. Thirty individuals were evaluated in a cross-sectional study, equally divided among controls (CG) and diabetic patients with (DNG) and without (DG) polyneuropathy. The acquired ground reaction forces and kinematic data were used as input variables for a scaled musculoskeletal model in the OpenSim software. The maximum isometric force of the ankle extensors and flexors was reduced in the model of DNG by 30% and 20%, respectively. The muscle force was calculated using static optimization, and peak forces were compared among groups (flexors and extensors of hip, knee, and ankle; ankle evertors; and hip abductors) using MANOVAs, followed by univariate ANOVAs and Newman-Keuls post-hoc tests (p < 0.05). From the middle to late stance phase, DG showed a lower soleus muscle peak force compared to the CG (p=0.024) and the DNG showed lower forces in the gastrocnemius medialis compared to the DG (p=0.037). At the terminal swing phase, the semitendinosus and semimembranosus peak forces showed lower values in the DG compared to the CG and DNG. At the late stance, the DNG showed a higher peak force in the biceps short head, semimembranosus, and semitendinosus compared to the CG and DG. Peak forces of ankle (flexors, extensors, and evertors), knee (flexors and extensors), and hip abductors distinguished DNG from DG, and both of those from CG. Both diabetic groups showed alterations in the force production of the ankle extensors with reductions in the forces of soleus (DG) and gastrocnemius medialis (DNG) seen in both diabetic groups, but only DNG showed an increase in the hamstrings (knee flexor) at push-off. A therapeutic approach focused on preserving the functionality of the knee muscles is a promising strategy, even if the ankle dorsiflexors and plantarflexors are included in the resistance training.

Retrograde monosynaptic tracing reveals the temporal evolution of inputs onto new neurons in the adult dentate gyrus and olfactory bulb

PubMed Central

Deshpande, Aditi; Bergami, Matteo; Ghanem, Alexander; Conzelmann, Karl-Klaus; Lepier, Alexandra; Götz, Magdalena; Berninger, Benedikt

2013-01-01

Identifying the connectome of adult-generated neurons is essential for understanding how the preexisting circuitry is refined by neurogenesis. Changes in the pattern of connectivity are likely to control the differentiation process of newly generated neurons and exert an important influence on their unique capacity to contribute to information processing. Using a monosynaptic rabies virus-based tracing technique, we studied the evolving presynaptic connectivity of adult-generated neurons in the dentate gyrus (DG) of the hippocampus and olfactory bulb (OB) during the first weeks of their life. In both neurogenic zones, adult-generated neurons first receive local connections from multiple types of GABAergic interneurons before long-range projections become established, such as those originating from cortical areas. Interestingly, despite fundamental similarities in the overall pattern of evolution of presynaptic connectivity, there were notable differences with regard to the development of cortical projections: although DG granule neuron input originating from the entorhinal cortex could be traced starting only from 3 to 5 wk on, newly generated neurons in the OB received input from the anterior olfactory nucleus and piriform cortex already by the second week. This early glutamatergic input onto newly generated interneurons in the OB was matched in time by the equally early innervations of DG granule neurons by glutamatergic mossy cells. The development of connectivity revealed by our study may suggest common principles for incorporating newly generated neurons into a preexisting circuit. PMID:23487772

TENTATIVE EVIDENCE FOR RELATIVISTIC ELECTRONS GENERATED BY THE JET OF THE YOUNG SUN-LIKE STAR DG Tau

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ainsworth, Rachael E.; Ray, Tom P.; Taylor, Andrew M.

2014-09-01

Synchrotron emission has recently been detected in the jet of a massive protostar, providing further evidence that certain jet formation characteristics for young stars are similar to those found for highly relativistic jets from active galactic nuclei. We present data at 325 and 610 MHz taken with the Giant Metrewave Radio Telescope of the young, low-mass star DG Tau, an analog of the Sun soon after its birth. This is the first investigation of a low-mass young stellar object at such low frequencies. We detect emission with a synchrotron spectral index in the proximity of the DG Tau jet and interpretmore » this emission as a prominent bow shock associated with this outflow. This result provides tentative evidence for the acceleration of particles to relativistic energies due to the shock impact of this otherwise very low-power jet against the ambient medium. We calculate the equipartition magnetic field strength B {sub min} ≈ 0.11 mG and particle energy E {sub min} ≈ 4 × 10{sup 40} erg, which are the minimum requirements to account for the synchrotron emission of the DG Tau bow shock. These results suggest the possibility of low energy cosmic rays being generated by young Sun-like stars.« less

Streptococcus mutans levels in saliva and distribution of serotypes among 9-year-old Icelandic children.

PubMed

Holbrook, W P; Beighton, D

1987-02-01

Streptococcus mutans levels in saliva were determined in 9-yr-old children from five towns in Iceland. In four towns the mean counts were greater than 10(5)/ml. Serotype c was predominant but types e and d/g were also found. The proportion of children harbouring serotype d/g alone or in combination with other serotypes was higher than that reported in most other studies.

Chemical structure determination of DNA bases modified by active metabolites of lucidin-3-O-primeveroside.

PubMed

Ishii, Yuji; Okamura, Toshiya; Inoue, Tomoki; Fukuhara, Kiyoshi; Umemura, Takashi; Nishikawa, Akiyoshi

2010-01-01

Lucidin-3-O- primeveroside (LuP) is one of the components of madder root (Rubia tinctorum L.; MR) which is reported to be carcinogenic in the kidney and liver of rats. Since metabolism of LuP generates genotoxic compounds such as lucidin (Luc) and rubiadin (Rub), it is likely that LuP plays a key role in MR carcinogenesis. In the present study, the chemical structures of Luc-specific 2'-deoxyguanosine (dG) and 2'-deoxyadenosine (dA) adducts following the reactions of dG and dA with a Luc carbocation or quinone methide intermediate derived from Acetoxy-Luc were determined by liquid chromatography with photodiode array and electron spray ionizaion-mass spectrometry (LC-PDA-ESI/MS). The identification of the two measurable adducts as Luc-N(2)-dG and Luc-N(6)-dA was confirmed by NMR analysis. Subsequently, using a newly developed quantitative analytical method using LC-ESI/MS, the formation of Luc-N(2)-dG and Luc-N(6)-dA from the reaction of calf thymus DNA with Luc in the presence of S9 mixture was observed. The fact that this reaction with Rub also gave rise to the same dG and dA adducts strongly suggests that Rub genotoxicity involves a metabolic conversion to Luc. The precise determination of the modified DNA bases generated by LuP and the method for their analysis may contribute to further comprehension of the mode of action underlying carcinogenesis by MR and related anthraquinones.

Glycation of H1 Histone by 3-Deoxyglucosone: Effects on Protein Structure and Generation of Different Advanced Glycation End Products

PubMed Central

Ashraf, Jalaluddin Mohammad; Rabbani, Gulam; Ahmad, Saheem; Hasan, Qambar; Khan, Rizwan Hasan; Alam, Khursheed; Choi, Inho

2015-01-01

Advanced glycation end products (AGEs) culminate from the non-enzymatic reaction between a free carbonyl group of a reducing sugar and free amino group of proteins. 3-deoxyglucosone (3-DG) is one of the dicarbonyl species that rapidly forms several protein-AGE complexes that are believed to be involved in the pathogenesis of several diseases, particularly diabetic complications. In this study, the generation of AGEs (Nε-carboxymethyl lysine and pentosidine) by 3-DG in H1 histone protein was characterized by evaluating extent of side chain modification (lysine and arginine) and formation of Amadori products as well as carbonyl contents using several physicochemical techniques. Results strongly suggested that 3-DG is a potent glycating agent that forms various intermediates and AGEs during glycation reactions and affects the secondary structure of the H1 protein. Structural changes and AGE formation may influence the function of H1 histone and compromise chromatin structures in cases of secondary diabetic complications. PMID:26121680

Modeling hippocampal neurogenesis using human pluripotent stem cells.

PubMed

Yu, Diana Xuan; Di Giorgio, Francesco Paolo; Yao, Jun; Marchetto, Maria Carolina; Brennand, Kristen; Wright, Rebecca; Mei, Arianna; McHenry, Lauren; Lisuk, David; Grasmick, Jaeson Michael; Silberman, Pedro; Silberman, Giovanna; Jappelli, Roberto; Gage, Fred H

2014-03-11

The availability of human pluripotent stem cells (hPSCs) offers the opportunity to generate lineage-specific cells to investigate mechanisms of human diseases specific to brain regions. Here, we report a differentiation paradigm for hPSCs that enriches for hippocampal dentate gyrus (DG) granule neurons. This differentiation paradigm recapitulates the expression patterns of key developmental genes during hippocampal neurogenesis, exhibits characteristics of neuronal network maturation, and produces PROX1+ neurons that functionally integrate into the DG. Because hippocampal neurogenesis has been implicated in schizophrenia (SCZD), we applied our protocol to SCZD patient-derived human induced pluripotent stem cells (hiPSCs). We found deficits in the generation of DG granule neurons from SCZD hiPSC-derived hippocampal NPCs with lowered levels of NEUROD1, PROX1, and TBR1, reduced neuronal activity, and reduced levels of spontaneous neurotransmitter release. Our approach offers important insights into the neurodevelopmental aspects of SCZD and may be a promising tool for drug screening and personalized medicine.

High-Performance High-Order Simulation of Wave and Plasma Phenomena

NASA Astrophysics Data System (ADS)

Klockner, Andreas

This thesis presents results aiming to enhance and broaden the applicability of the discontinuous Galerkin ("DG") method in a variety of ways. DG was chosen as a foundation for this work because it yields high-order finite element discretizations with very favorable numerical properties for the treatment of hyperbolic conservation laws. In a first part, I examine progress that can be made on implementation aspects of DG. In adapting the method to mass-market massively parallel computation hardware in the form of graphics processors ("GPUs"), I obtain an increase in computation performance per unit of cost by more than an order of magnitude over conventional processor architectures. Key to this advance is a recipe that adapts DG to a variety of hardware through automated self-tuning. I discuss new parallel programming tools supporting GPU run-time code generation which are instrumental in the DG self-tuning process and contribute to its reaching application floating point throughput greater than 200 GFlops/s on a single GPU and greater than 3 TFlops/s on a 16-GPU cluster in simulations of electromagnetics problems in three dimensions. I further briefly discuss the solver infrastructure that makes this possible. In the second part of the thesis, I introduce a number of new numerical methods whose motivation is partly rooted in the opportunity created by GPU-DG: First, I construct and examine a novel GPU-capable shock detector, which, when used to control an artificial viscosity, helps stabilize DG computations in gas dynamics and a number of other fields. Second, I describe my pursuit of a method that allows the simulation of rarefied plasmas using a DG discretization of the electromagnetic field. Finally, I introduce new explicit multi-rate time integrators for ordinary differential equations with multiple time scales, with a focus on applicability to DG discretizations of time-dependent problems.

Impairment of photoreceptor ribbon synapses in a novel Pomt1 conditional knockout mouse model of dystroglycanopathy.

PubMed

Rubio-Fernández, Marcos; Uribe, Mary Luz; Vicente-Tejedor, Javier; Germain, Francisco; Susín-Lara, Cristina; Quereda, Cristina; Montoliu, Lluis; de la Villa, Pedro; Martín-Nieto, José; Cruces, Jesús

2018-06-04

Hypoglycosylation of α-dystroglycan (α-DG) resulting from deficiency of protein O-mannosyltransferase 1 (POMT1) may cause severe neuromuscular dystrophies with brain and eye anomalies, named dystroglycanopathies. The retinal involvement of these disorders motivated us to generate a conditional knockout (cKO) mouse experiencing a Pomt1 intragenic deletion (exons 3-4) during the development of photoreceptors, mediated by the Cre recombinase expressed from the cone-rod homeobox (Crx) gene promoter. In this mouse, retinal α-DG was unglycosylated and incapable of binding laminin. Retinal POMT1 deficiency caused significant impairments in both electroretinographic recordings and optokinetic reflex in Pomt1 cKO mice, and immunohistochemical analyses revealed the absence of β-DG and of the α-DG-interacting protein, pikachurin, in the outer plexiform layer (OPL). At the ultrastructural level, noticeable alterations were observed in the ribbon synapses established between photoreceptors and bipolar cells. Therefore, O-mannosylation of α-DG in the retina carried out by POMT1 is crucial for the establishment of proper synapses at the OPL and transmission of visual information from cones and rods to their postsynaptic neurons.

Q3DG: A computer program for strain-energy-release rates for delamination growth in composite laminates

NASA Technical Reports Server (NTRS)

Raju, I. S.

1986-01-01

The Q3DG is a computer program developed to perform a quasi-three-dimensional stress analysis for composite laminates which may contain delaminations. The laminates may be subjected to mechanical, thermal, and hygroscopic loads. The program uses the finite element method and models the laminates with eight-noded parabolic isoparametric elements. The program computes the strain-energy-release components and the total strain-energy release in all three modes for delamination growth. A rectangular mesh and data file generator, DATGEN, is included. The DATGEN program can be executed interactively and is user friendly. The documentation includes sections dealing with the Q3D analysis theory, derivation of element stiffness matrices and consistent load vectors for the parabolic element. Several sample problems with the input for Q3DG and output from the program are included. The capabilities of the DATGEN program are illustrated with examples of interactive sessions. A microfiche of all the examples is included. The Q3DG and DATGEN programs have been implemented on CYBER 170 class computers. Q3DG and DATGEN were developed at the Langley Research Center during the early eighties and documented in 1984 to 1985.

Leukemia cells demonstrate a different metabolic perturbation provoked by 2-deoxyglucose.

PubMed

Miwa, Hiroshi; Shikami, Masato; Goto, Mineaki; Mizuno, Shohei; Takahashi, Miyuki; Tsunekawa-Imai, Norikazu; Ishikawa, Takamasa; Mizutani, Motonori; Horio, Tomohiro; Gotou, Mayuko; Yamamoto, Hidesuke; Wakabayashi, Motohiro; Watarai, Masaya; Hanamura, Ichiro; Imamura, Akira; Mihara, Hidetsugu; Nitta, Masakazu

2013-05-01

The shift in energy metabolism from oxidative phosphorylation to glycolysis can serve as a target for the inhibition of cancer growth. Here, we examined the metabolic changes induced by 2-deoxyglucose (2-DG), a glycolysis inhibitor, in leukemia cells by metabolome analysis. NB4 cells mainly utilized glucose as an energy source by glycolysis and oxidative phosphorylation in mitochondria, since metabolites in the glycolytic pathway and in the tricarboxylic acid (TCA) cycle were significantly decreased by 2-DG. In THP-1 cells, metabolites in the TCA cycle were not decreased to the same extent by 2-DG as in NB4 cells, which indicates that THP-1 utilizes energy sources other than glucose. TCA cycle metabolites in THP-1 cells may be derived from acetyl-CoA by fatty acid β-oxidation, which was supported by abundant detection of carnitine and acetylcarnitine in THP-1 cells. 2-DG treatment increased the levels of pentose phosphate pathway (PPP) metabolites and augmented the generation of NADPH by glucose-6-phosphate dehydrogenase. An increase in NADPH and upregulation of glutathione synthetase expression resulted in the increase in the reduced form of glutathione by 2-DG in NB4 cells. We demonstrated that a combination of 2-DG and inhibition of PPP by dehydroepiandrosterone (DHEA) effectively suppressed the growth of NB4 cells. The replenishment of the TCA cycle by fatty acid oxidation by carnitine palmitoyltransferase in THP-1 cells, treated by 2-DG, might be regulated by AMPK, as the combination of 2-DG and inhibition of AMPK by compound C potently suppressed the growth of THP-1 cells. Although 2-DG has been effective in preclinical and clinical studies, this treatment has not been fully explored due to concerns related to potential toxicities such as brain toxicity at high doses. We demonstrated that a combination of 2-DG and DHEA or compound C at a relatively low concentration effectively inhibits the growth of NB4 and THP-1 cells, respectively. These observations may aid in the identification of appropriate combinations of metabolic inhibitors at low concentrations which do not cause toxicities.

Autologous intramuscular transplantation of engineered satellite cells induces exosome-mediated systemic expression of Fukutin-related protein and rescues disease phenotype in a murine model of limb-girdle muscular dystrophy type 2I.

PubMed

Frattini, Paola; Villa, Chiara; De Santis, Francesca; Meregalli, Mirella; Belicchi, Marzia; Erratico, Silvia; Bella, Pamela; Raimondi, Manuela Teresa; Lu, Qilong; Torrente, Yvan

2017-10-01

α-Dystroglycanopathies are a group of muscular dystrophies characterized by α-DG hypoglycosylation and reduced extracellular ligand-binding affinity. Among other genes involved in the α-DG glycosylation process, fukutin related protein (FKRP) gene mutations generate a wide range of pathologies from mild limb girdle muscular dystrophy 2I (LGMD2I), severe congenital muscular dystrophy 1C (MDC1C), to Walker-Warburg Syndrome and Muscle-Eye-Brain disease. FKRP gene encodes for a glycosyltransferase that in vivo transfers a ribitol phosphate group from a CDP -ribitol present in muscles to α-DG, while in vitro it can be secreted as monomer of 60kDa. Consistently, new evidences reported glycosyltransferases in the blood, freely circulating or wrapped within vesicles. Although the physiological function of blood stream glycosyltransferases remains unclear, they are likely released from blood borne or distant cells. Thus, we hypothesized that freely or wrapped FKRP might circulate as an extracellular glycosyltransferase, able to exert a "glycan remodelling" process, even at distal compartments. Interestingly, we firstly demonstrated a successful transduction of MDC1C blood-derived CD133+ cells and FKRP L276IKI mouse derived satellite cells by a lentiviral vector expressing the wild-type of human FKRP gene. Moreover, we showed that LV-FKRP cells were driven to release exosomes carrying FKRP. Similarly, we observed the presence of FKRP positive exosomes in the plasma of FKRP L276IKI mice intramuscularly injected with engineered satellite cells. The distribution of FKRP protein boosted by exosomes determined its restoration within muscle tissues, an overall recovery of α-DG glycosylation and improved muscle strength, suggesting a systemic supply of FKRP protein acting as glycosyltransferase. © The Author 2017. Published by Oxford University Press.

77 FR 39745 - Fuel Oil Systems for Emergency Power Supplies

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-05

... fuel oil systems for safety-related emergency diesel generators and oil-fueled gas turbine generators... emergency diesel generators and oil-fueled gas turbine generators, including assurance of adequate fuel oil.... The DG-1282 is proposed revision 2 of Regulatory Guide 1.137, ``Fuel Oil Systems for Standby Diesel...

Immunogenicity of a novel Clade B HIV-1 vaccine combination: Results of phase 1 randomized placebo controlled trial of an HIV-1 GM-CSF-expressing DNA prime with a modified vaccinia Ankara vaccine boost in healthy HIV-1 uninfected adults

PubMed Central

Grunenberg, Nicole A.; Sanchez, Brittany J.; Seaton, Kelly E.; Ferrari, Guido; Moody, M. Anthony; Frahm, Nicole; Montefiori, David C.; Hay, Christine M.; Goepfert, Paul A.; Baden, Lindsey R.; Robinson, Harriet L.; Yu, Xuesong; Gilbert, Peter B.; McElrath, M. Juliana; Huang, Yunda; Tomaras, Georgia D.

2017-01-01

Background A phase 1 trial of a clade B HIV vaccine in HIV-uninfected adults evaluated the safety and immunogenicity of a DNA prime co-expressing GM-CSF (Dg) followed by different numbers and intervals of modified vaccinia Ankara Boosts (M). Both vaccines produce virus-like particles presenting membrane-bound Env. Methods Four US sites randomized 48 participants to receiving 1/10th the DNA dose as DgDgMMM given at 0, 2, 4, 6 and 8 months, or full dose DgDgM_M or DgDgMM_M regimens, given at 0, 2, 4, and 8 months, and 0, 2, 4, 6, and 10 months, respectively. Peak immunogenicity was measured 2 weeks post-last vaccination. Results All regimens were well tolerated and safe. Full dose DgDgM_M and DgDgMM_M regimens generated Env-specific IgG to HIV-1 Env in >90%, IgG3 in >80%, and IgA in <20% of participants. Responses to gp140 and gp41 targets were more common and of higher magnitude than to gp120 and V1V2. The gp41 antibody included reactivity to the conserved immunodominant region with specificities known to mediate virus capture and phagocytosis and did not cross-react with a panel of intestinal flora antigens. The 3rd dose of MVA increased the avidity of elicited antibody (7.5% to 39%), the ADCC response to Bal gp120 (14% to 64%), and the one-year durability of the IgG3 responses to gp41 by 4-fold (13% vs. 3.5% retention of peak response). The co-expressed GM-CSF did not enhance responses over those in trials testing this vaccine without GM-CSF. Conclusion This DNA/MVA prime-boost regimen induced durable, functional humoral responses that included ADCC, high antibody avidity, and Env IgG1 and IgG3 binding responses to the immunodominant region of gp41. The third, spaced MVA boost improved the overall quality of the antibody response. These products without co-expressed GM-CSF but combined with protein boosts will be considered for efficacy evaluation. Trial registration ClinicalTrials.gov NCT01571960 PMID:28727817

Immunogenicity of a novel Clade B HIV-1 vaccine combination: Results of phase 1 randomized placebo controlled trial of an HIV-1 GM-CSF-expressing DNA prime with a modified vaccinia Ankara vaccine boost in healthy HIV-1 uninfected adults.

PubMed

Buchbinder, Susan P; Grunenberg, Nicole A; Sanchez, Brittany J; Seaton, Kelly E; Ferrari, Guido; Moody, M Anthony; Frahm, Nicole; Montefiori, David C; Hay, Christine M; Goepfert, Paul A; Baden, Lindsey R; Robinson, Harriet L; Yu, Xuesong; Gilbert, Peter B; McElrath, M Juliana; Huang, Yunda; Tomaras, Georgia D

2017-01-01

A phase 1 trial of a clade B HIV vaccine in HIV-uninfected adults evaluated the safety and immunogenicity of a DNA prime co-expressing GM-CSF (Dg) followed by different numbers and intervals of modified vaccinia Ankara Boosts (M). Both vaccines produce virus-like particles presenting membrane-bound Env. Four US sites randomized 48 participants to receiving 1/10th the DNA dose as DgDgMMM given at 0, 2, 4, 6 and 8 months, or full dose DgDgM_M or DgDgMM_M regimens, given at 0, 2, 4, and 8 months, and 0, 2, 4, 6, and 10 months, respectively. Peak immunogenicity was measured 2 weeks post-last vaccination. All regimens were well tolerated and safe. Full dose DgDgM_M and DgDgMM_M regimens generated Env-specific IgG to HIV-1 Env in >90%, IgG3 in >80%, and IgA in <20% of participants. Responses to gp140 and gp41 targets were more common and of higher magnitude than to gp120 and V1V2. The gp41 antibody included reactivity to the conserved immunodominant region with specificities known to mediate virus capture and phagocytosis and did not cross-react with a panel of intestinal flora antigens. The 3rd dose of MVA increased the avidity of elicited antibody (7.5% to 39%), the ADCC response to Bal gp120 (14% to 64%), and the one-year durability of the IgG3 responses to gp41 by 4-fold (13% vs. 3.5% retention of peak response). The co-expressed GM-CSF did not enhance responses over those in trials testing this vaccine without GM-CSF. This DNA/MVA prime-boost regimen induced durable, functional humoral responses that included ADCC, high antibody avidity, and Env IgG1 and IgG3 binding responses to the immunodominant region of gp41. The third, spaced MVA boost improved the overall quality of the antibody response. These products without co-expressed GM-CSF but combined with protein boosts will be considered for efficacy evaluation. ClinicalTrials.gov NCT01571960.

2-Deoxy-D-Glucose Modified Magnetic Nanoparticles with Dual Functional Properties: Nanothermotherapy and Magnetic Resonance Imaging.

PubMed

Zhao, Lingyun; Zheng, Yajing; Yan, Hao; Xie, WenSheng; Sun, Xiaodan; Li, Ning; Tang, Jintian

2016-03-01

Superparamagnetic iron oxide nanoparticles (SPIONs) with appropriate surface chemistry have attracted wild attention in medical and biological application because of their current and potential usefulness such as magnetic resonance imaging (MRI) contrast enhancement, magnetic mediated hyperthermia (MMH), immunoassay, and in drug delivery, etc. In this study, we investigated the MRI contrast agents and MMH mediators properties of the novel 2-deoxy-D-glucose (2-DG) modified SPIONs. As a non-metabolizable glucose analogue, 2-DG can block glycolysis and inhibits protein glycosylation. Moreover, SPIONs coated with 2-DG molecules can be particularly attractive to resource-hungry cancer cells, therefore to realize the targeting strategy for the SPIONs. SPIONs with amino silane as the capping agent for amino-group surface modification were synthesized by the chemical co-precipitation method with modification. Glutaraldehyde was further applied as an activation agent through which 2-DG was conjugated to the amino-coated SPIONs. Physicochemical characterizations of the 2-DG-SPIONs, such as surface morphology, surface charge and magnetic properties were investigated by Transmission Electron Microscopy (TEM), ζ-Potential and Vibrating Sample Magnetometer (VSM), etc. Magnetic inductive heating characteristics of the 2-DG-SPIONs were analyzed by exposing the SPIONs suspension (magnetic fluid) under alternative magnetic field (AMF). U-251 human glioma cells with expression of glucose transport proteins type 1 and 3 (GLUT1 and GLUT 3), and L929 murine fibroblast cell as negative control, were employed to study the effect of 2-DG modification on the cell uptake for SPIONs. TEM images for ultra-thin sections as well as ICP-MS were applied to evaluate the SPIONs internalization within the cells. In vitro MRI was performed after cells were co-incubated with SPIONs and the T2 relaxation time was measured and compared. The results demonstrate that 2-DG-SPIONs were supermagnetic and in spherical shape with -10 nm diameter. Possessing ideal magnetic inductive heating characteristics, which can generate very rapid and efficient heating while upon AMF exposure, 2-DG-SPIONs can be applied as novel candidature of magnetic nanothermotherapy for cancer treatment. Modification of 2-DG can greatly promote the cell uptake of SPIONs and such cellular uptake of 2-DG-SPIONs was time dependent. Surface coating by 2-DG can remarkably enhance the MR imaging ability for the SPIONs on the cells of U251 cancer cells. In summary, our investigation provides a novel glucose analogue modified SPIONs with potential application in the targeting cancer nanothermotherapy and MR imaging.

Effect of boundary treatments on quantum transport current in the Green's function and Wigner distribution methods for a nano-scale DG-MOSFET

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang Haiyan; Department of Mathematics and Statistics, University of North Carolina at Charlotte, Charlotte, NC 28223-0001; Cai Wei

2010-06-20

In this paper, we conduct a study of quantum transport models for a two-dimensional nano-size double gate (DG) MOSFET using two approaches: non-equilibrium Green's function (NEGF) and Wigner distribution. Both methods are implemented in the framework of the mode space methodology where the electron confinements below the gates are pre-calculated to produce subbands along the vertical direction of the device while the transport along the horizontal channel direction is described by either approach. Each approach handles the open quantum system along the transport direction in a different manner. The NEGF treats the open boundaries with boundary self-energy defined by amore » Dirichlet to Neumann mapping, which ensures non-reflection at the device boundaries for electron waves leaving the quantum device active region. On the other hand, the Wigner equation method imposes an inflow boundary treatment for the Wigner distribution, which in contrast ensures non-reflection at the boundaries for free electron waves entering the device active region. In both cases the space-charge effect is accounted for by a self-consistent coupling with a Poisson equation. Our goals are to study how the device boundaries are treated in both transport models affects the current calculations, and to investigate the performance of both approaches in modeling the DG-MOSFET. Numerical results show mostly consistent quantum transport characteristics of the DG-MOSFET using both methods, though with higher transport current for the Wigner equation method, and also provide the current-voltage (I-V) curve dependence on various physical parameters such as the gate voltage and the oxide thickness.« less

Jovian Plasma Modeling for Mission Design

NASA Technical Reports Server (NTRS)

Garrett, Henry B.; Kim, Wousik; Belland, Brent; Evans, Robin

2015-01-01

The purpose of this report is to address uncertainties in the plasma models at Jupiter responsible for surface charging and to update the jovian plasma models using the most recent data available. The updated plasma environment models were then used to evaluate two proposed Europa mission designs for spacecraft charging effects using the Nascap-2k code. The original Divine/Garrett jovian plasma model (or "DG1", T. N. Divine and H. B. Garrett, "Charged particle distributions in Jupiter's magnetosphere," J. Geophys. Res., vol. 88, pp. 6889-6903,1983) has not been updated in 30 years, and there are known errors in the model. As an example, the cold ion plasma temperatures between approx.5 and 10 Jupiter radii (Rj) were found by the experimenters who originally published the data to have been underestimated by approx.2 shortly after publication of the original DG1 model. As knowledge of the plasma environment is critical to any evaluation of the surface charging at Jupiter, the original DG1 model needed to be updated to correct for this and other changes in our interpretation of the data so that charging levels could beproperly estimated using the Nascap-2k charging code. As an additional task, the Nascap-2k spacecraft charging tool has been adapted to incorporate the so-called Kappa plasma distribution function--an important component of the plasma model necessary to compute the particle fluxes between approx.5 keV and 100 keV (at the outset of this study,Nascap-2k did not directly incorporate this common representation of the plasma thus limiting the accuracy of our charging estimates). The updating of the DG1 model and its integration into the Nascap-2k design tool means that charging concerns can now be more efficiently evaluated and mitigated. (We note that, given the subsequent decision by the Europa project to utilize solar arrays for its baseline design, surface charging effects have becomeeven more of an issue for its mission design). The modifications and results of those modifications to the DG1 model to produce the new DG2 model presented here and the steps taken to integrate the DG2 predictions into Nascap-2k are described in this report

Jovian plasma modeling for mission design

NASA Technical Reports Server (NTRS)

Garrett, Henry B.; Kim, Wousik; Belland, Brent; Evans, Robin

2015-01-01

The purpose of this report is to address uncertainties in the plasma models at Jupiter responsible for surface charging and to update the jovian plasma models using the most recent data available. The updated plasma environment models were then used to evaluate two proposed Europa mission designs for spacecraft charging effects using the Nascap-2k code. The original Divine/Garrett jovian plasma model (or "DG1", T. N. Divine and H. B. Garrett, "Charged particle distributions in Jupiter's magnetosphere," J. Geophys. Res., vol. 88, pp. 6889-6903,1983) has not been updated in 30 years, and there are known errors in the model. As an example, the cold ion plasma temperatures between approx.5 and 10 Jupiter radii (Rj) were found by the experimenters who originally published the data to have been underestimated by approx.2 shortly after publication of the original DG1 model. As knowledge of the plasma environment is critical to any evaluation of the surface charging at Jupiter, the original DG1 model needed to be updated to correct for this and other changes in our interpretation of the data so that charging levels could beproperly estimated using the Nascap-2k charging code. As an additional task, the Nascap-2k spacecraft charging tool has been adapted to incorporate the so-called Kappa plasma distribution function--an important component of the plasma model necessary to compute the particle fluxes between approx.5 keV and 100 keV (at the outset of this study,Nascap-2k did not directly incorporate this common representation of the plasma thus limiting the accuracy of our charging estimates). The updating of the DG1 model and its integration into the Nascap-2k design tool means that charging concerns can now be more efficiently evaluated and mitigated. (We note that, given the subsequent decision by the Europa project to utilize solar arrays for its baseline design, surface charging effects have becomeeven more of an issue for its mission design). The modifications and results of those modifications to the DG1 model to produce the new DG2 model presented here and the steps taken to integrate the DG2 predictions into Nascap-2k are described in this report.

Control of dispatch dynamics for lowering the cost of distributed generation in the built environment

NASA Astrophysics Data System (ADS)

Flores, Robert Joseph

Distributed generation can provide many benefits over traditional central generation such as increased reliability and efficiency while reducing emissions. Despite these potential benefits, distributed generation is generally not purchased unless it reduces energy costs. Economic dispatch strategies can be designed such that distributed generation technologies reduce overall facility energy costs. In this thesis, a microturbine generator is dispatched using different economic control strategies, reducing the cost of energy to the facility. Several industrial and commercial facilities are simulated using acquired electrical, heating, and cooling load data. Industrial and commercial utility rate structures are modeled after Southern California Edison and Southern California Gas Company tariffs and used to find energy costs for the simulated buildings and corresponding microturbine dispatch. Using these control strategies, building models, and utility rate models, a parametric study examining various generator characteristics is performed. An economic assessment of the distributed generation is then performed for both the microturbine generator and parametric study. Without the ability to export electricity to the grid, the economic value of distributed generation is limited to reducing the individual costs that make up the cost of energy for a building. Any economic dispatch strategy must be built to reduce these individual costs. While the ability of distributed generation to reduce cost depends of factors such as electrical efficiency and operations and maintenance cost, the building energy demand being serviced has a strong effect on cost reduction. Buildings with low load factors can accept distributed generation with higher operating costs (low electrical efficiency and/or high operations and maintenance cost) due to the value of demand reduction. As load factor increases, lower operating cost generators are desired due to a larger portion of the building load being met in an effort to reduce demand. In addition, buildings with large thermal demand have access to the least expensive natural gas, lowering the cost of operating distributed generation. Recovery of exhaust heat from DG reduces cost only if the buildings thermal demand coincides with the electrical demand. Capacity limits exist where annual savings from operation of distributed generation decrease if further generation is installed. For low operating cost generators, the approximate limit is the average building load. This limit decreases as operating costs increase. In addition, a high capital cost of distributed generation can be accepted if generator operating costs are low. As generator operating costs increase, capital cost must decrease if a positive economic performance is desired.

Multi-scale and multi-physics simulations using the multi-fluid plasma model

DTIC Science & Technology

2017-04-25

small The simulation uses 512 second-order elements Bz = 1.0, Te = Ti = 0.01, ui = ue = 0 ne = ni = 1.0 + e−10(x−6) 2 Baboolal, Math . and Comp. Sim. 55...DISTRIBUTION Clearance No. 17211 23 / 31 SUMMARY The blended finite element method (BFEM) is presented DG spatial discretization with explicit Runge...Kutta (i+, n) CG spatial discretization with implicit Crank-Nicolson (e−, fileds) DG captures shocks and discontinuities CG is efficient and robust for

PSO Algorithm for an Optimal Power Controller in a Microgrid

NASA Astrophysics Data System (ADS)

Al-Saedi, W.; Lachowicz, S.; Habibi, D.; Bass, O.

2017-07-01

This paper presents the Particle Swarm Optimization (PSO) algorithm to improve the quality of the power supply in a microgrid. This algorithm is proposed for a real-time selftuning method that used in a power controller for an inverter based Distributed Generation (DG) unit. In such system, the voltage and frequency are the main control objectives, particularly when the microgrid is islanded or during load change. In this work, the PSO algorithm is implemented to find the optimal controller parameters to satisfy the control objectives. The results show high performance of the applied PSO algorithm of regulating the microgrid voltage and frequency.

Multi-Dimensional Quantum Effect Simulation Using a Density-Gradient Model and Script-Level Programming Techniques

NASA Technical Reports Server (NTRS)

Rafferty, Connor S.; Biegel, Bryan A.; Yu, Zhi-Ping; Ancona, Mario G.; Bude, J.; Dutton, Robert W.; Saini, Subhash (Technical Monitor)

1998-01-01

A density-gradient (DG) model is used to calculate quantum-mechanical corrections to classical carrier transport in MOS (Metal Oxide Semiconductor) inversion/accumulation layers. The model is compared to measured data and to a fully self-consistent coupled Schrodinger and Poisson equation (SCSP) solver. Good agreement is demonstrated for MOS capacitors with gate oxide as thin as 21 A. It is then applied to study carrier distribution in ultra short MOSFETs (Metal Oxide Semiconductor Field Effect Transistor) with surface roughness. This work represents the first implementation of the DG formulation on multidimensional unstructured meshes. It was enabled by a powerful scripting approach which provides an easy-to-use and flexible framework for solving the fourth-order PDEs (Partial Differential Equation) of the DG model.

Adult Hippocampal Neurogenesis, Aging and Neurodegenerative Diseases: Possible Strategies to Prevent Cognitive Impairment.

PubMed

Vivar, Carmen

2015-01-01

The adult brain of humans and other mammals continuously generates new neurons throughout life. However, this neurogenic capacity is limited to two brain areas, the dentate gyrus (DG of the hippocampus and the subventricular zone (SVZ of the lateral ventricle. Although the DG generates new neurons, its neurogenic capacity declines with age and neurodegenerative diseases such as Alzheimer's disease (AD and Huntington's disease (HD. This review focuses on the role of newly-born neurons in cognitive processes, and discusses some of the strategies proposed in humans and animals to enhance neurogenesis and counteract age-related cognitive deficits, such as physical exercise and intake of natural products like omega-3 fatty acids, curcumin and flavanols.

Final Technical Report for Contract No. DE-EE0006332, "Integrated Simulation Development and Decision Support Tool-Set for Utility Market and Distributed Solar Power Generation"

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cormier, Dallas; Edra, Sherwin; Espinoza, Michael

This project will enable utilities to develop long-term strategic plans that integrate high levels of renewable energy generation, and to better plan power system operations under high renewable penetration. The program developed forecast data streams for decision support and effective integration of centralized and distributed solar power generation in utility operations. This toolset focused on real time simulation of distributed power generation within utility grids with the emphasis on potential applications in day ahead (market) and real time (reliability) utility operations. The project team developed and demonstrated methodologies for quantifying the impact of distributed solar generation on core utility operations,more » identified protocols for internal data communication requirements, and worked with utility personnel to adapt the new distributed generation (DG) forecasts seamlessly within existing Load and Generation procedures through a sophisticated DMS. This project supported the objectives of the SunShot Initiative and SUNRISE by enabling core utility operations to enhance their simulation capability to analyze and prepare for the impacts of high penetrations of solar on the power grid. The impact of high penetration solar PV on utility operations is not only limited to control centers, but across many core operations. Benefits of an enhanced DMS using state-of-the-art solar forecast data were demonstrated within this project and have had an immediate direct operational cost savings for Energy Marketing for Day Ahead generation commitments, Real Time Operations, Load Forecasting (at an aggregate system level for Day Ahead), Demand Response, Long term Planning (asset management), Distribution Operations, and core ancillary services as required for balancing and reliability. This provided power system operators with the necessary tools and processes to operate the grid in a reliable manner under high renewable penetration.« less

Monte Carlo evaluation of glandular dose in cone-beam X-ray computed tomography dedicated to the breast: Homogeneous and heterogeneous breast models.

PubMed

Sarno, Antonio; Mettivier, Giovanni; Tucciariello, Raffaele M; Bliznakova, Kristina; Boone, John M; Sechopoulos, Ioannis; Di Lillo, Francesca; Russo, Paolo

2018-06-07

In cone-beam computed tomography dedicated to the breast (BCT), the mean glandular dose (MGD) is the dose metric of reference, evaluated from the measured air kerma by means of normalized glandular dose coefficients (DgN CT ). This work aimed at computing, for a simple breast model, a set of DgN CT values for monoenergetic and polyenergetic X-ray beams, and at validating the results vs. those for patient specific digital phantoms from BCT scans. We developed a Monte Carlo code for calculation of monoenergetic DgN CT coefficients (energy range 4.25-82.25 keV). The pendant breast was modelled as a cylinder of a homogeneous mixture of adipose and glandular tissue with glandular fractions by mass of 0.1%, 14.3%, 25%, 50% or 100%, enveloped by a 1.45 mm-thick skin layer. The breast diameter ranged between 8 cm and 18 cm. Then, polyenergetic DgN CT coefficients were analytically derived for 49-kVp W-anode spectra (half value layer 1.25-1.50 mm Al), as in a commercial BCT scanner. We compared the homogeneous models to 20 digital phantoms produced from classified 3D breast images. Polyenergetic DgN CT resulted 13% lower than most recent published data. The comparison vs. patient specific breast phantoms showed that the homogeneous cylindrical model leads to a DgN CT percentage difference between -15% and +27%, with an average overestimation of 8%. A dataset of monoenergetic and polyenergetic DgN CT coefficients for BCT was provided. Patient specific breast models showed a different volume distribution of glandular dose and determined a DgN CT 8% lower, on average, than homogeneous breast model. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Effects of Environmental Enrichment on Doublecortin and BDNF Expression along the Dorso-Ventral Axis of the Dentate Gyrus.

PubMed

Gualtieri, Fabio; Brégère, Catherine; Laws, Grace C; Armstrong, Elena A; Wylie, Nicholas J; Moxham, Theo T; Guzman, Raphael; Boswell, Timothy; Smulders, Tom V

2017-01-01

Adult hippocampal neurogenesis (AHN) in the dentate gyrus is known to respond to environmental enrichment, chronic stress, and many other factors. The function of AHN may vary across the septo-temporal axis of the hippocampus, as different subdivisions are responsible for different functions. The dorsal pole regulates cognitive-related behaviors, while the ventral pole mediates mood-related responses through the hypothalamic-pituitary-adrenal (HPA) axis. In this study, we investigate different methods of quantifying the effect of environmental enrichment on AHN in the dorsal and ventral parts of the dentate gyrus (dDG and vDG). To this purpose, 11-week-old female CD-1 mice were assigned for 8 days to one of two conditions: the Environmental Enrichment (E) group received (i) running wheels, (ii) larger cages, (iii) plastic tunnels, and (iv) bedding with male urine, while the Control (C) group received standard housing. Dorsal CA ( Cornu Ammonis ) and DG regions were larger in the E than the C animals. Distance run linearly predicted the volume of the dorsal hippocampus, as well as of the intermediate and ventral CA regions. In the dDG, the amount of Doublecortin (DCX) immunoreactivity was significantly higher in E than in C mice. Surprisingly, this pattern was the opposite in the vDG (C > E). Real-time PCR measurement of Dcx mRNA and DCX protein analysis using ELISA showed the same pattern. Brain Derived Neurotrophic Factor (BDNF) immunoreactivity and mRNA displayed no difference between E and C, suggesting that upregulation of DCX was not caused by changes in BDNF levels. BDNF levels were higher in vDG than in dDG, as measured by both methods. Bdnf expression in vDG correlated positively with the distance run by individual E mice. The similarity in the patterns of immunoreactivity, mRNA and protein for differential DCX expression and for BDNF distribution suggests that the latter two methods might be effective tools for more rapid quantification of AHN.

The Direct Georeferencing Application and Performance Analysis of Uav Helicopter in Gcp-Free Area

NASA Astrophysics Data System (ADS)

Lo, C. F.; Tsai, M. L.; Chiang, K. W.; Chu, C. H.; Tsai, G. J.; Cheng, C. K.; El-Sheimy, N.; Ayman, H.

2015-08-01

There are many disasters happened because the weather changes extremely in these years. To facilitate applications such as environment detection or monitoring becomes very important. Therefore, the development of rapid low cost systems for collecting near real-time spatial information is very critical. Rapid spatial information collection has become an emerging trend for remote sensing and mapping applications. This study develops a Direct Georeferencing (DG) based Unmanned Aerial Vehicle (UAV) helicopter photogrammetric platform where an Inertial Navigation System (INS)/Global Navigation Satellite System (GNSS) integrated Positioning and Orientation System (POS) system is implemented to provide the DG capability of the platform. The performance verification indicates that the proposed platform can capture aerial images successfully. A flight test is performed to verify the positioning accuracy in DG mode without using Ground Control Points (GCP). The preliminary results illustrate that horizontal DG positioning accuracies in the x and y axes are around 5 meter with 100 meter flight height. The positioning accuracy in the z axis is less than 10 meter. Such accuracy is good for near real-time disaster relief. The DG ready function of proposed platform guarantees mapping and positioning capability even in GCP free environments, which is very important for rapid urgent response for disaster relief. Generally speaking, the data processing time for the DG module, including POS solution generalization, interpolation, Exterior Orientation Parameters (EOP) generation, and feature point measurements, is less than 1 hour.

Identification, Characterization and Clinical Development of the New Generation of Breast Cancer Susceptibility Alleles

DTIC Science & Technology

2007-03-01

Gohrke S, SchŸrmann P, Bogdanova N, Dšrk T , Fagerholm R , Aaltonen K, Blomqvist C, Nevanlinna H, Seal S, Renwick A, Stratton MR, Rahman N, Sangrajrang...Easton DF, Sodha N, Seal S, Barfoot R , Mangion J, Chang-Claude J, Eccles D, Eeles RA, Evans DG, Houlston RS, Murday VA, Narod S, Peretz T , Peto J...Barfoot R , Chagtai T , Jayatilake H, McGuffog L, Hanks S, Evans DG, Eccles D, The Breast Cancer Susceptibility Collaboration (UK), Easton DF and

Androgens enhance in vivo 2-deoxyglucose uptake by rat striated muscle

NASA Technical Reports Server (NTRS)

Max, S. R.; Toop, J.

1983-01-01

It is shown that testosterone propionate (TP) causes a striking increase in the in vivo uptake of 2-deoxyglucose (2-DG) by the levator ani muscle of immature male rats, which was found to be uniformly distributed over the entire muscle. After a single subcutaneous injection of TP, no enhancement of 2-DG was observed before 3.5 hr, at which time uptake was increased 2-fold; maximum enhancement (4-fold) was attained at 12 hr. At 72 hr, 2-DG uptake remained elevated at twice the control value. It was determined that the effect of TP probably is mediated by specific androgen receptors. In addition, it was found that the effect of TP was blocked by the simultaneous administration of an androgen antagonist, cyproterone acetate. TP also was found to enhance the uptake of 2-DG in the bulbocavernosus (253 percent over control) and extensor digitorum longus muscles (150 percent over control), but not in the biceps brachii or soleus. It is suggested that the increased uptake of glucose may be an important early step in the anabolic response of muscle to androgens.

GSK-3β Overexpression Alters the Dendritic Spines of Developmentally Generated Granule Neurons in the Mouse Hippocampal Dentate Gyrus.

PubMed

Pallas-Bazarra, Noemí; Kastanauskaite, Asta; Avila, Jesús; DeFelipe, Javier; Llorens-Martín, María

2017-01-01

The dentate gyrus (DG) plays a crucial role in hippocampal-related memory. The most abundant cellular type in the DG, namely granule neurons, are developmentally generated around postnatal day P6 in mice. Moreover, a unique feature of the DG is the occurrence of adult hippocampal neurogenesis, a process that gives rise to newborn granule neurons throughout life. Adult-born and developmentally generated granule neurons share some maturational aspects but differ in others, such as in their positioning within the granule cell layer. Adult hippocampal neurogenesis encompasses a series of plastic changes that modify the function of the hippocampal trisynaptic network. In this regard, it is known that glycogen synthase kinase 3β (GSK-3β) regulates both synaptic plasticity and memory. By using a transgenic mouse overexpressing GSK-3β in hippocampal neurons, we previously demonstrated that the overexpression of this kinase has deleterious effects on the maturation of newborn granule neurons. In the present study, we addressed the effects of GSK-3β overexpression on the morphology and number of dendritic spines of developmentally generated granule neurons. To this end, we performed intracellular injections of Lucifer Yellow in developmentally generated granule neurons of wild-type and GSK-3β-overexpressing mice and analyzed the number and morphologies of dendritic spines (namely, stubby, thin and mushroom). GSK-3β overexpression led to a general reduction in the number of dendritic spines. In addition, it caused a slight reduction in the percentage, head diameter and length of thin spines, whereas the head diameter of mushroom spines was increased.

GSK-3β Overexpression Alters the Dendritic Spines of Developmentally Generated Granule Neurons in the Mouse Hippocampal Dentate Gyrus

PubMed Central

Pallas-Bazarra, Noemí; Kastanauskaite, Asta; Avila, Jesús; DeFelipe, Javier; Llorens-Martín, María

2017-01-01

The dentate gyrus (DG) plays a crucial role in hippocampal-related memory. The most abundant cellular type in the DG, namely granule neurons, are developmentally generated around postnatal day P6 in mice. Moreover, a unique feature of the DG is the occurrence of adult hippocampal neurogenesis, a process that gives rise to newborn granule neurons throughout life. Adult-born and developmentally generated granule neurons share some maturational aspects but differ in others, such as in their positioning within the granule cell layer. Adult hippocampal neurogenesis encompasses a series of plastic changes that modify the function of the hippocampal trisynaptic network. In this regard, it is known that glycogen synthase kinase 3β (GSK-3β) regulates both synaptic plasticity and memory. By using a transgenic mouse overexpressing GSK-3β in hippocampal neurons, we previously demonstrated that the overexpression of this kinase has deleterious effects on the maturation of newborn granule neurons. In the present study, we addressed the effects of GSK-3β overexpression on the morphology and number of dendritic spines of developmentally generated granule neurons. To this end, we performed intracellular injections of Lucifer Yellow in developmentally generated granule neurons of wild-type and GSK-3β-overexpressing mice and analyzed the number and morphologies of dendritic spines (namely, stubby, thin and mushroom). GSK-3β overexpression led to a general reduction in the number of dendritic spines. In addition, it caused a slight reduction in the percentage, head diameter and length of thin spines, whereas the head diameter of mushroom spines was increased. PMID:28344548

Ruminal and intestinal degradability of distillers grains plus solubles varies by source.

PubMed

Kleinschmit, D H; Anderson, J L; Schingoethe, D J; Kalscheur, K F; Hippen, A R

2007-06-01

Currently in the dairy industry, there is a concern about the variability in the nutrient content among sources of distillers grains plus solubles (DG), but little research has evaluated the variability in metabolizable AA among sources. The ruminal degradability of crude protein (CP) in soybean meal (SBM), dried DG from 5 sources (DG1, DG2, DG3, DG4, and DG5), and 1 source of wet DG (WDG) were determined using 2 lactating ruminally cannulated Holstein cows. Feeds were incubated in the rumen for 3, 6, 12, 18, 24, and 36 h. Intestinal CP digestibility via pepsin and pancreatin and AA profiles were measured on residue from 12-h ruminal incubation of feeds. Ruminal undegradable protein (RUP) was less for SBM (46.4%) than for DG. The WDG (53.6%) had less RUP than dried DG. The RUP concentrations of DG3 (59.1%) and DG5 (60.3%) were lower than DG1 (71.7%) and DG4 (67.5%), with DG1 having more than DG2 (63.7%) and DG4. Intestinal digestibility of RUP was greater for SBM (86.7%) than DG. The DG2 (76.8%) and DG3 (74.2%) had greater intestinal digestibility compared with DG1 (59.2%), DG4 (63.0%), and DG5 (68.1%). The intestinal digestibility in WDG (65.8%) was similar to all other DG except for DG1, which was lower. Total digestibility of CP was greater in SBM (93.9%) compared with DG. Among the DG sources, the CP in DG2 (85.3%) and DG3 (84.9%) was more digestible compared with DG1 (70.7%), DG4 (74.9%), and DG5 (80.8%) but not WDG (81.9%). Based on the milk protein score (MPS), which is an estimate of the proportion of milk protein that a protein source can sustain until the first limiting AA is depleted, Met was the first limiting AA in SBM and Lys in DG. The concentrations of essential AA in the RUP were not different among DG sources, but the greater MPS in WDG (0.306) compared with the dried DG (0.240) sources indicated that WDG may have been the more ideal RUP source; but, the MPS of the metabolizable protein indicated that the protein quality of WDG was similar to that in DG2, DG3, and DG5. In conclusion, protein degradability and digestibility differed greatly among DG sources, but these differences were actually not as prominent in the concentrations of metabolizable AA and MPS among these sources.

Matrix Metalloproteinase 9 Displays a Particular Time Response to Acute Stress: Variation in Its Levels and Activity Distribution in Rat Hippocampus.

PubMed

Aguayo, Felipe I; Pacheco, Aníbal A; García-Rojo, Gonzalo J; Pizarro-Bauerle, Javier A; Doberti, Ana V; Tejos, Macarena; García-Pérez, María A; Rojas, Paulina S; Fiedler, Jenny L

2018-05-16

A single stress exposure facilitates memory formation through neuroplastic processes that reshape excitatory synapses in the hippocampus, probably requiring changes in extracellular matrix components. We tested the hypothesis that matrix metalloproteinase 9 (MMP-9), an enzyme that degrades components of extracellular matrix and synaptic proteins such as β-dystroglycan (β-DG 43 ), changes their activity and distribution in rat hippocampus during the acute stress response. After 2.5 h of restraint stress, we found (i) increased MMP-9 levels and potential activity in whole hippocampal extracts, accompanied by β-DG 43 cleavage, and (ii) a significant enhancement of MMP-9 immunoreactivity in dendritic fields such as stratum radiatum and the molecular layer of hippocampus. After 24 h of stress, we found that (i) MMP-9 net activity rises at somatic field, i.e., stratum pyramidale and granule cell layers, and also at synaptic field, mainly stratum radiatum and the molecular layer of hippocampus, and (ii) hippocampal synaptoneurosome fractions are enriched with MMP-9, without variation of its potential enzymatic activity, in accordance with the constant level of cleaved β-DG 43 . These findings indicate that stress triggers a peculiar timing response in the MMP-9 levels, net activity, and subcellular distribution in the hippocampus, suggesting its involvement in the processing of substrates during the stress response.

A comparison study of the application of data assimilation in the short-term prediction of radiation and precipitation

NASA Astrophysics Data System (ADS)

Ding, Huang; Cui, Fang; Wang, Zhijia; Zhou, Hai; Chen, Weidong

2018-03-01

Based on the meteorological observation of the DG plants in East China, the assimilation effect of the WRF in the summer of 2016 was studied. The results show that, in the case of using data assimilation, the model correctly predicted the occurrence time of precipitation, as well as the variation of the precipitation along with the time were well consistent with the observations, which gives more accurate downward shortwave radiation. The application of data assimilation techniques can provide reliable information to adapt to the high resolution of meso-scale meteorological model. Therefore, it provides the necessary technical support for the development of the distributed power generation.

Changes in deciduous and permanent dentinal tubules diameter after several conditioning protocols: In vitro study.

PubMed

de Los Angeles Moyaho-Bernal, María; Contreras-Bulnes, Rosalía; Rodríguez-Vilchis, Laura Emma; Rubio-Rosas, Efraín

2018-05-08

Innovators conditioning protocols are emerged in permanent dentin, however for deciduous dentin the information is limited; the aim of this study was to evaluate in vitro diameter of deciduous and permanent dentinal tubules after several conditioning protocols. Eighty dentin samples were distributed in sixteen groups (n = 5 p/g) and dentin surface was conditioned as follow: G1D/G1P acid etching; G2D/G2P, self-etch adhesive; G3D/G3P, G4D/G4P, Er: YAG laser irradiation at 200 mJ-25.5 J/cm 2 and 300 mJ-38.2 J/cm 2 , at 10 Hz under water spray respectively; G5D/G5P, G6D/G6P, G7D/G7P, and G8D/G8P were irradiated under the same energy densities followed phosphoric acid or self-etch adhesive conditioning. The sample dentin of deciduous and permanent teeth was analyzed with scanning electron microscopy and tubule diameter was evaluated by Image Tools Scandium program. Data were subjected to one-way analysis ANOVA to compare among groups with a level of significance at p ≤ .05. For deciduous dentin, diameters were from 1.52 ± 0.32 µm in G3D to 3.88 ± 0.37 µm in G1D; narrowest and widest diameter, respectively (p < .000). While permanent dentin tubules exhibited diameters from 1.16 ± 0.16/1.19 ± 0.12 µm in G7P/G8P to 2.76 ± 0.28 µm in G6P; narrowest and widest diameter, respectively (p < .000). All dentin conditioning protocols produced more open dentin tubules (diameter size) in deciduous dentin than permanent, specific conditioning protocols are required for each tissue (deciduous or permanent dentin), since same protocol produced stronger effects on primary dentin, which is important for dental clinical success in children and adolescents. © 2018 Wiley Periodicals, Inc.

Effects of Environmental Enrichment on Doublecortin and BDNF Expression along the Dorso-Ventral Axis of the Dentate Gyrus

PubMed Central

Gualtieri, Fabio; Brégère, Catherine; Laws, Grace C.; Armstrong, Elena A.; Wylie, Nicholas J.; Moxham, Theo T.; Guzman, Raphael; Boswell, Timothy; Smulders, Tom V.

2017-01-01

Adult hippocampal neurogenesis (AHN) in the dentate gyrus is known to respond to environmental enrichment, chronic stress, and many other factors. The function of AHN may vary across the septo-temporal axis of the hippocampus, as different subdivisions are responsible for different functions. The dorsal pole regulates cognitive-related behaviors, while the ventral pole mediates mood-related responses through the hypothalamic-pituitary-adrenal (HPA) axis. In this study, we investigate different methods of quantifying the effect of environmental enrichment on AHN in the dorsal and ventral parts of the dentate gyrus (dDG and vDG). To this purpose, 11-week-old female CD-1 mice were assigned for 8 days to one of two conditions: the Environmental Enrichment (E) group received (i) running wheels, (ii) larger cages, (iii) plastic tunnels, and (iv) bedding with male urine, while the Control (C) group received standard housing. Dorsal CA (Cornu Ammonis) and DG regions were larger in the E than the C animals. Distance run linearly predicted the volume of the dorsal hippocampus, as well as of the intermediate and ventral CA regions. In the dDG, the amount of Doublecortin (DCX) immunoreactivity was significantly higher in E than in C mice. Surprisingly, this pattern was the opposite in the vDG (C > E). Real-time PCR measurement of Dcx mRNA and DCX protein analysis using ELISA showed the same pattern. Brain Derived Neurotrophic Factor (BDNF) immunoreactivity and mRNA displayed no difference between E and C, suggesting that upregulation of DCX was not caused by changes in BDNF levels. BDNF levels were higher in vDG than in dDG, as measured by both methods. Bdnf expression in vDG correlated positively with the distance run by individual E mice. The similarity in the patterns of immunoreactivity, mRNA and protein for differential DCX expression and for BDNF distribution suggests that the latter two methods might be effective tools for more rapid quantification of AHN. PMID:28966570

Properties of jet engine combustion particles during the PartEmis experiment: Particle size spectra (d > 15 nm) and volatility

NASA Astrophysics Data System (ADS)

Nyeki, S.; Gysel, M.; Weingartner, E.; Baltensperger, U.; Hitzenberger, R.; Petzold, A.; Wilson, C. W.

2004-09-01

Size distributions (d > 15 nm) and volatile properties of combustion particles were measured during test-rig experiments on a jet engine, consisting of a combustor and three simulated turbine stages (HES). The combustor was operated to simulate legacy (inlet temperature 300°C) and contemporary (500°C) cruise conditions, using kerosene with three different fuel sulfur contents (FSC; 50, 400 and 1300 μg g-1). Measurements found that contemporary cruise conditions resulted in lower number emission indices (EIN15) and higher geometric mean particle diameter (dG) than for legacy conditions. Increasing FSC resulted in an overall increase in EIN15 and decrease in dG. The HES stages or fuel additive (APA101) had little influence on EIN15 or dG, however, this is uncertain due to the measurement variability. EIN15 for non-volatile particles was largely independent of all examined conditions.

77 FR 19063 - Airworthiness Directives; DG Flugzeugbau GmbH Gliders

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-30

... Airworthiness Directives; DG Flugzeugbau GmbH Gliders AGENCY: Federal Aviation Administration (FAA), Department... (AD) for DG Flugzeugbau GmbH Models DG-500 Elan Orion, DG-500 Elan Trainer, DG-500/ 20 Elan, DG-500/22... identified in this AD, contact DG- Flugzeugbau GmbH, Otto-Lilienthal-Weg 2, 76646 Bruchsal, Federal Republic...

Neurofibromin Modulates Adult Hippocampal Neurogenesis and Behavioral Effects of Antidepressants

PubMed Central

Li, Yun; Li, Yanjiao; McKay, Renée M.; Riethmacher, Dieter; Parada, Luis F.

2012-01-01

Neurogenesis persists in the rodent dentate gyrus (DG) throughout adulthood but declines with age and stress. Neural progenitor cells (NPCs) residing in the subgranular zone of the DG are regulated by an array of growth factors and respond to the microenvironment, adjusting their proliferation level to determine the rate of neurogenesis. Here we report that genetic deletion of neurofibromin (Nf1), a tumor suppressor with RAS-GAP activity,in adult NPCs enhanced DG proliferation and increased generation of new neurons in mice. Nf1 loss-associated neurogenesis had the functional effect of enhancing behavioral responses to subchronic antidepressants and, over time, led to spontaneous antidepressive-like behaviors. Thus, our findings establish an important role for the Nf1-Ras pathway in regulating adult hippocampal neurogenesis, and demonstrate that activation of adult NPCs is sufficient to modulate depression- and anxiety-like behaviors. PMID:22399775

Genetic analysis for the grain number heterosis of a super-hybrid rice WFYT025 combination using RNA-Seq.

PubMed

Chen, Liang; Bian, Jianmin; Shi, Shilai; Yu, Jianfeng; Khanzada, Hira; Wassan, Ghulam Mustafa; Zhu, Changlan; Luo, Xin; Tong, Shan; Yang, Xiaorong; Peng, Xiaosong; Yong, Shuang; Yu, Qiuying; He, Xiaopeng; Fu, Junru; Chen, Xiaorong; Hu, Lifang; Ouyang, Linjuan; He, Haohua

2018-06-15

Despite the great contributions of utilizing heterosis to crop productivity worldwide, the molecular mechanism of heterosis remains largely unexplored. Thus, the present research is focused on the grain number heterosis of a widely used late-cropping indica super hybrid rice combination in China using a high-throughput next-generation RNA-seq strategy. Here, we obtained 872 million clean reads, and at least one read could maps 27,917 transcripts out of 35,679 annotations. Transcript differential expression analysis revealed a total of 5910 differentially expressed genes (DG HP ) between super-hybrid rice Wufengyou T025 (WFYT025) and its parents were identified in the young panicles. Out of the 5910 DG HP , 63.1% had a genetic action mode of over-dominance, 17.3% had a complete-dominance action, 15.6% had a partial-dominance action and 4.0% had an additive action. DG HP were significantly enriched in carotenoid biosynthesis, diterpenoid biosynthesis and plant hormone signal transduction pathways, with the key genes involved in the three pathways being up-regulated in the hybrid. By comparing the DG HP enriched in the KEGG pathway with QTLs associated with grain number, several DG HP were located on the same chromosomal segment with some of these grain number QTLs. Through young panicle development transcriptome analysis, we conclude that the over-dominant effect is probably the major contributor to the grain number heterosis of WFYT025. The DG HP sharing the same location with grain number QTLs could be considered a candidate gene and provide valuable targets for the cloning and functional analysis of these grain number QTLs.

The ADER-DG method for seismic wave propagation and earthquake rupture dynamics

NASA Astrophysics Data System (ADS)

Pelties, Christian; Gabriel, Alice; Ampuero, Jean-Paul; de la Puente, Josep; Käser, Martin

2013-04-01

We will present the Arbitrary high-order DERivatives Discontinuous Galerkin (ADER-DG) method for solving the combined elastodynamic wave propagation and dynamic rupture problem. The ADER-DG method enables high-order accuracy in space and time while being implemented on unstructured tetrahedral meshes. A tetrahedral element discretization provides rapid and automatized mesh generation as well as geometrical flexibility. Features as mesh coarsening and local time stepping schemes can be applied to reduce computational efforts without introducing numerical artifacts. The method is well suited for parallelization and large scale high-performance computing since only directly neighboring elements exchange information via numerical fluxes. The concept of fluxes is a key ingredient of the numerical scheme as it governs the numerical dispersion and diffusion properties and allows to accommodate for boundary conditions, empirical friction laws of dynamic rupture processes, or the combination of different element types and non-conforming mesh transitions. After introducing fault dynamics into the ADER-DG framework, we will demonstrate its specific advantages in benchmarking test scenarios provided by the SCEC/USGS Spontaneous Rupture Code Verification Exercise. An important result of the benchmark is that the ADER-DG method avoids spurious high-frequency contributions in the slip rate spectra and therefore does not require artificial Kelvin-Voigt damping, filtering or other modifications of the produced synthetic seismograms. To demonstrate the capabilities of the proposed scheme we simulate an earthquake scenario, inspired by the 1992 Landers earthquake, that includes branching and curved fault segments. Furthermore, topography is respected in the discretized model to capture the surface waves correctly. The advanced geometrical flexibility combined with an enhanced accuracy will make the ADER-DG method a useful tool to study earthquake dynamics on complex fault systems in realistic rheologies.

Autonomous Decentralized Control of Supply and Demand by Inverter Based Distributed Generations in Isolated Microgrid

NASA Astrophysics Data System (ADS)

Shiki, Akira; Yokoyama, Akihiko; Baba, Jyunpei; Takano, Tomihiro; Gouda, Takahiro; Izui, Yoshio

Recently, because of the environmental burden mitigation, energy conservations, energy security, and cost reductions, distributed generations are attracting our strong attention. These distributed generations (DGs) have been already installed to the distribution system, and much more DGs will be expected to be connected in the future. On the other hand, a new concept called “Microgrid” which is a small power supply network consisting of only DGs was proposed and some prototype projects are ongoing in Japan. The purpose of this paper is to develop the three-phase instantaneous valued digital simulator of microgrid consisting of a lot of inverter based DGs and to develop a supply and demand control method in isolated microgrid. First, microgrid is modeled using MATLAB/SIMULINK. We develop models of three-phase instantaneous valued inverter type CVCF generator, PQ specified generator, PV specified generator, PQ specified load as storage battery, photovoltaic generation, fuel cell and inverter load respectively. Then we propose an autonomous decentralized control method of supply and demand in isolated microgrid where storage batteries, fuel cells, photovoltaic generations and loads are connected. It is proposed here that the system frequency is used as a means to control DG output. By changing the frequency of the storage battery due to unbalance of supply and demand, all inverter based DGs detect the frequency fluctuation and change their own outputs. Finally, a new frequency control method in autonomous decentralized control of supply and demand is proposed. Though the frequency is used to transmit the information on the supply and demand unbalance to DGs, after the frequency plays the role, the frequency finally has to return to a standard value. To return the frequency to the standard value, the characteristic curve of the fuel cell is shifted in parallel. This control is carried out corresponding to the fluctuation of the load. The simulation shows that the frequency can be controlled well and has been made clear the effectiveness of the frequency control system.

Coronavirus Infection in Ferrets: Antigen Distribution and Inflammatory Response.

PubMed

Doria-Torra, G; Vidaña, B; Ramis, A; Amarilla, S P; Martínez, J

2016-11-01

Multisystemic granulomatous lesions are the most common finding in ferrets infected by ferret systemic coronavirus (FRSCV). To characterize the inflammatory response developed against this virus, lesions from 4 naturally infected ferrets were examined. Lesions were classified into the 4 known types of granulomas (granulomas without necrosis [G], granulomas with necrosis [G-N], granulomas with neutrophils [G-NL], and diffuse granulomatous inflammation [DG]). The cellular composition of the lesions was characterized on the basis of cellular morphology and immunohistochemistry using markers for T and B-lymphocytes, plasma cells, macrophages, and neutrophils. The extent and distribution of viral antigen expression was also assessed. In G lesions, macrophages were mainly located in the center of the granuloma, with a moderate number of T-lymphocytes scattered among the macrophages, plasma cells, and B-lymphocytes. G-N lesions exhibited a necrotic center surrounded by abundant macrophages, some T-lymphocytes, plasma cells, and a few B-lymphocytes. In G-NL lesions, there was a central area dominated by neutrophils with low numbers of macrophages, plasma cells, and lymphocytes. DG presented similar cell proportions, but distributed evenly throughout the lesions. FRSCV was expressed in G, G-NL, G-N, and DG, with decreasing numbers of immunoreactive cells. This study reveals the important role of macrophages in the inflammatory response of ferrets against the virus and the variable proportions of leukocytes among different types of lesions, indicating their variable age. The results also confirm the similarities of the disease in ferrets to feline infectious peritonitis. © The Author(s) 2016.

Evaluation of modified dichloran 18% glycerol (DG18) agar for enumerating fungi in wheat flour: a collaborative study.

PubMed

Beuchat, L R; Hwang, C A

1996-04-01

Dichloran 18% glycerol agar base supplemented with 100 micrograms of chloramphenicol ml-1 (DG18 agar) was compared to DG18 agar supplemented with 100 micrograms of Triton X-301 ml-1 (DG18T) and DG18 agar supplemented with 1 microgram of iprodione [3-(3,5-dichlorophenyl)-N-(1-methyl-ethyl)-2,4-dioxo-1-imidazolidine- carboxamide] ml-1 (DG18I agar) for enumeration of fungi in ten brands of wheat flour. As the flours contained low fungal populations, all were inoculated with two to four strains of xerophilic fungi (Aspergillus candidus, A. penicillioides, Eurotium amstelodami, E. intermedium, E. repens, E. rubrum, E. tonophilum, E. umbrosum and Wallemia sebi), after which counts ranged from 3.87 to 6.37 log10 CFU g-1. Significantly higher populations (p < 0.05) were detected in four flours: three were on DG18T compared to DG18 and DG18I agar. A. candidus had been inoculated into all three flours. E. amstelodami, E. intermedium, E. repens or E. tonophilum had also been inoculated into at least one of the three flours showing significantly higher numbers of CFU on DG18T agar. Analysis of collapsed data from all samples showed that DG18T agar was significantly better than DG18 or DG18I agars at p < 0.10 but not at p < 0.05. Coefficients of variation for reproducibility (among-laboratory variation) were 8.4%, 7.5% and 8.6%, respectively, for DG18, DG18T and DG18I agars. DG18I agar restricted colony development most, especially for Eurotium species. Naturally occurring Penicillium species grew equally well on DG18 and DG18T agars, whereas W. sebi grew well on all three media. DG18T agar was judged to be superior to DG18 and DG18I agars for enumerating fungi in wheat flours.

77 FR 21400 - Airworthiness Directives; DG Flugzeugbau GmbH Sailplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-10

... Airworthiness Directives; DG Flugzeugbau GmbH Sailplanes AGENCY: Federal Aviation Administration (FAA... directive (AD) for DG Flugzeugbau GmbH Models DG-500 Elan Orion, DG-500 Elan Trainer, DG-500/ 20 Elan, and...., Washington, DC 20590. For service information identified in this AD, contact DG Flugzeugbau GmbH, Otto...

Oxidatively damaged DNA in the nasal epithelium of workers occupationally exposed to silica dust in Tuscany region, Italy.

PubMed

Peluso, Marco E M; Munnia, Armelle; Giese, Roger W; Chellini, Elisabetta; Ceppi, Marcello; Capacci, Fabio

2015-07-01

Chronic silica exposure has been associated to cancer and silicosis. Furthermore, the induction of oxidative stress and the generation of reactive oxygen species have been indicated to play a main role in the carcinogenicity of respirable silica. Therefore, we conducted a cross-sectional study to evaluate the prevalence of 3-(2-deoxy-β-D-erythro-pentafuranosyl)pyrimido[1,2-α]purin-10(3H)-one deoxyguanosine (M1dG) adducts, a biomarker of oxidative stress and peroxidation of lipids, in the nasal epithelium of 135 silica-exposed workers, employed in pottery, ceramic and marble manufacturing plants as well as in a stone quarry, in respect to 118 controls living in Tuscany region, Italy. The M1dG generation was measured by the (32)P-postlabelling assay. Significant higher levels of M1dG adducts per 10(8) normal nucleotides were observed in the nasal epithelium of smokers, 77.9±9.8 (SE), and in those of former smokers, 80.7±9.7 (SE), as compared to non-smokers, 57.1±6.2 (SE), P = 0.001 and P = 0.004, respectively. Significant increments of M1dG adducts were found in the nasal epithelium of workers that handle artificial marble conglomerates, 184±36.4 (SE), and in those of quarry workers, 120±34.7 (SE), with respect to controls, 50.6±2.7 (SE), P = 0.014 and P < 0.001, respectively. Null increments were observed in association with the pottery and the ceramic factories. After stratification for different exposures, silica-exposed workers that were co-exposed to organic solvents, and welding and exhaust fumes have significantly higher M1dG levels, 90.4±13.4 (SE), P = 0.014 vs. Our data suggested that silica exposure might be associated with genotoxicity in the nasal epithelial cells of silica-exposed workers that handle of artificial marble conglomerates and quarry workers. Importantly, we observed that co-exposures to other respiratory carcinogens may have contributed to enhance the burden of M1dG adducts in the nasal epithelium of silica-exposed workers. © The Author 2015. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effects of alternate-day feeding of dried distiller's grain plus solubles to forage-fed beef cows in mid- to late gestation.

PubMed

Klein, S I; Steichen, P L; Islas, A; Goulart, R S; Gilbery, T C; Bauer, M L; Swanson, K C; Dahlen, C R

2014-06-01

Forty-six nonlactating beef cows were used to examine effects of dried distiller's grains plus solubles (DG) supplementation strategies to cows fed grass hay during mid- to late gestation on BW, ultrasound body composition characteristics, concentrations of serum NEFA and urea, feeding behavior, and calf birth weight. Cows were assigned to dietary treatments in a completely randomized design: 1) control, where hay was fed each day of the week (CON), 2) both hay and DG fed daily during the week (DG7), 3) hay fed daily but DG fed 3 d of the week (DG3), and 4) hay fed 4 d of the week alternating with DG fed on the remaining 3 d (DGA). Hay was offered ad libitum on days it was fed. The DG were fed at 0.40% of BW when offered daily and 0.93% of BW when offered 3 d per week (Monday, Wednesday, and Friday). Feed intake was monitored continuously over the 84-d feeding period. Hay intake and total DMI were reduced (P < 0.05) in DGA compared with DG7 and DG3. Gain and G:F were decreased (P < 0.05) for CON compared with other treatments. No differences (P > 0.05) were observed among treatments for change in BCS, intramuscular fat, rib fat, or rump fat from d 1 to 84. On a day when DG7, DG3, and DGA all received DG (Friday), DGA had reduced (P < 0.05) concentrations of urea compared with DG3 and DG7. On a day when only DG7 received DG (Saturday), urea was greater (P < 0.01) for DG3 and DGA compared with DG7, and concentrations of NEFA were greater (P < 0.01) in CON and DGA compared with DG7. On the second consecutive day when only DG7 received DG (Sunday), concentrations of NEFA were less (P < 0.001) for DG7 compared with other treatments. On days when all cows received hay, DGA spent more time eating (P < 0.05) compared with DG7 and DG3. Cows fed DGA had greater (P < 0.05) hay intake per meal and time per meal compared with other treatments. On days when DG7, DG3, and DGA all received DG, cows in the DG3 and DGA treatments had greater (P < 0.05) number of DG meals, time spent eating, intake per meal, and time per meal but a slower (P < 0.05) rate of DG intake compared with DG7. No differences (P > 0.05) were observed in calf birth weights among treatments. The alternate-day feeding strategy reduced hay and total intake, altered concentrations of serum urea and NEFA, and altered feeding behavior compared with other supplementation methods.

Enabling Delay of Gratification Behavior in Those Not So Predisposed: The Moderating Role of Social Support

PubMed Central

Liu, Xiaoyan; Wang, Lei; Liao, Jiangqun

2016-01-01

The presence of delay of gratification (DG) in childhood is correlated with success later in a person's life. Is there any way of helping adults with a low level of DG to obtain similar success? The present research examines how social support helps those low in DG nonetheless to act similarly to those high in DG. This research includes both correlational studies and experiments that manipulate social support as well as both field studies and a laboratory study. The results show that with high social support, employees (Study 1) and university students (Study 2) low in DG report vocational and academic DG behavioral intentions, respectively, similar to those high in DG. Study 3 found that participants low in DG who were primed with high social support expressed job-choice DG similar to those high in the DG. Study 4 controlled for mood and self-image and found that participants low in DG who were primed with high social support expressed more money-choice DG than those high in the DG. Study 5 showed that social support moderated the relationship between DG and actual DG behaviors. These findings provide evidence for a moderating role of social support in the expression of DG behavior. PMID:27047408

Protection of Radial Glial-Like Cells in the Hippocampus of APP/PS1 Mice: a Novel Mechanism of Memantine in the Treatment of Alzheimer's Disease.

PubMed

Sun, Dayu; Chen, Junhua; Bao, Xiaohang; Cai, Yulong; Zhao, Jinghui; Huang, Jing; Huang, Wei; Fan, Xiaotang; Xu, Haiwei

2015-08-01

The failure of adult neurogenesis in the hippocampal dentate gyrus (DG) is closely correlated with memory decline in Alzheimer's disease (AD). Radial glial-like cells (RGLs) localized to the adult DG generate intermediate progenitor cells and immature neurons and thus contribute to adult hippocampus neurogenesis. Memantine (MEM) has been indicated to dramatically increase hippocampal neurogenesis by promoting the proliferation of RGLs. In this study, we examined the effect of MEM on the capacity for hippocampal cell proliferation and the amount of RGLs in APPswe/PS1∆E9 transgenic (APP/PS1) mice between 9 and 13 months of age. MEM could enhance hippocampal neurogenesis and increase the number of RGLs in the DG subgranular zone (DG-SGZ) of APP/PS1 mice of both ages. Moreover, MEM decreased amyloidogenesis in 13-month-old APP/PS1 mice and protected cultured radial glia cells (RGCs, L2.3 cells) from apoptosis induced by the β amyloid peptide (Aβ). Additionally, MEM inhibited microglial activation in a vertical process in DG-SGZ of APP/PS1 mice and decreased interacting with RGL processes. Reelin is involved in the proliferation of RGLs in the hippocampus, which was typically upregulated in the hippocampus of APP/PS1 mice by MEM and thought to be an active signaling pathway associated with the MEM-induced increase in RGLs. Our data suggest a previously uncharacterized role for MEM in treating AD.

Investigation and statistical modeling of InAs-based double gate tunnel FETs for RF performance enhancement

NASA Astrophysics Data System (ADS)

Poorvasha, S.; Lakshmi, B.

2018-05-01

In this paper, RF performance analysis of InAs-based double gate (DG) tunnel field effect transistors (TFETs) is investigated in both qualitative and quantitative fashion. This investigation is carried out by varying the geometrical and doping parameters of TFETs to extract various RF parameters, unity gain cut-off frequency (f t), maximum oscillation frequency (f max), intrinsic gain and admittance (Y) parameters. An asymmetric gate oxide is introduced in the gate-drain overlap and compared with that of DG TFETs. Higher ON-current (I ON) of about 0.2 mA and less leakage current (I OFF) of 29 fA is achieved for DG TFET with gate-drain overlap. Due to increase in transconductance (g m), higher f t and intrinsic gain is attained for DG TFET with gate-drain overlap. Higher f max of 985 GHz is obtained for drain doping of 5 × 1017 cm‑3 because of the reduced gate-drain capacitance (C gd) with DG TFET with gate-drain overlap. In terms of Y-parameters, gate oxide thickness variation offers better performance due to the reduced values of C gd. A second order numerical polynomial model is generated for all the RF responses as a function of geometrical and doping parameters. The simulation results are compared with this numerical model where the predicted values match with the simulated values. Project supported by the Department of Science and Technology, Government of India under SERB Scheme (No. SERB/F/2660).

ORACLE (Oversight of Resources and Capability for Logistics Effectiveness) and Requirements Forecasting. Volume 3. Predicting the Peacetime Spares Requirements.

DTIC Science & Technology

1988-05-01

Shearing Machines WR/MMI DG 3446 Forging Machinery and Hammers WR/MMI DG 3447 Wire and Metal Ribbon Forming Machines WR/MMI DG 3448 Riveting Machines ...R/MN1I DG 3449 Miscellaneous Secondary Metal Forming & Cutting WR/MMI DG Machinery 3450 Machine Tools, Portable WR/MMI DG 3455 Cutting Tools for...Secondary Metalworking Machinery WR/MMI DG WR 3465 Production Jigs, Fixtures and Templates WR/MMI DG WR 3470 Machine Shop Sets, Kits, and Outfits WR/MMI DG

A distributed query execution engine of big attributed graphs.

PubMed

Batarfi, Omar; Elshawi, Radwa; Fayoumi, Ayman; Barnawi, Ahmed; Sakr, Sherif

2016-01-01

A graph is a popular data model that has become pervasively used for modeling structural relationships between objects. In practice, in many real-world graphs, the graph vertices and edges need to be associated with descriptive attributes. Such type of graphs are referred to as attributed graphs. G-SPARQL has been proposed as an expressive language, with a centralized execution engine, for querying attributed graphs. G-SPARQL supports various types of graph querying operations including reachability, pattern matching and shortest path where any G-SPARQL query may include value-based predicates on the descriptive information (attributes) of the graph edges/vertices in addition to the structural predicates. In general, a main limitation of centralized systems is that their vertical scalability is always restricted by the physical limits of computer systems. This article describes the design, implementation in addition to the performance evaluation of DG-SPARQL, a distributed, hybrid and adaptive parallel execution engine of G-SPARQL queries. In this engine, the topology of the graph is distributed over the main memory of the underlying nodes while the graph data are maintained in a relational store which is replicated on the disk of each of the underlying nodes. DG-SPARQL evaluates parts of the query plan via SQL queries which are pushed to the underlying relational stores while other parts of the query plan, as necessary, are evaluated via indexless memory-based graph traversal algorithms. Our experimental evaluation shows the efficiency and the scalability of DG-SPARQL on querying massive attributed graph datasets in addition to its ability to outperform the performance of Apache Giraph, a popular distributed graph processing system, by orders of magnitudes.

Reliability evaluation of microgrid considering incentive-based demand response

NASA Astrophysics Data System (ADS)

Huang, Ting-Cheng; Zhang, Yong-Jun

2017-07-01

Incentive-based demand response (IBDR) can guide customers to adjust their behaviour of electricity and curtail load actively. Meanwhile, distributed generation (DG) and energy storage system (ESS) can provide time for the implementation of IBDR. The paper focus on the reliability evaluation of microgrid considering IBDR. Firstly, the mechanism of IBDR and its impact on power supply reliability are analysed. Secondly, the IBDR dispatch model considering customer’s comprehensive assessment and the customer response model are developed. Thirdly, the reliability evaluation method considering IBDR based on Monte Carlo simulation is proposed. Finally, the validity of the above models and method is studied through numerical tests on modified RBTS Bus6 test system. Simulation results demonstrated that IBDR can improve the reliability of microgrid.

Flux-lock type of superconducting fault current limiters: A comprehensive review

NASA Astrophysics Data System (ADS)

Badakhshan, M.; Mousavi G., S. M.

2018-04-01

Power systems must be developed and extended to supply the continuous enhancement of demands for electrical energy. This development of systems in addition to the integration of distributed generation (DG) units to the power systems results higher capacity of system. Hence, short circuit current of network is confronted with persistent increasing. Since exploration of high temperature superconducting (HTS) materials, superconducting fault current limiters (SFCLs) have attracted a lot of attention all over the world. There are different types of SFCLs. Flux-lock type of SFCL because of its characteristics in fault current limitation is an important category of SFCLs. This paper aims to present a comprehensive review of research activities and applications of Flux-lock type of SFCLs in power systems.

77 FR 67679 - Biweekly Notice; Applications and Amendments to Facility Operating Licenses and Combined Licenses...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-13

... diesel generator surveillance requirements. Margin of safety is related to the ability of the fission... surveillance tests, allowing testing in any MODE of operation. The Division 3 AC sources, including the diesel generator (DG) and its associated emergency loads are accident mitigating features, not accident initiators...

Antigastric parietal cell and antithyroid autoantibodies in patients with desquamative gingivitis.

PubMed

Chang, Julia Yu-Fong; Chiang, Chun-Pin; Wang, Yi-Ping; Wu, Yang-Che; Chen, Hsin-Ming; Sun, Andy

2017-04-01

Desquamative gingivitis (DG) is principally associated with erosive oral lichen planus (EOLP), mucous membrane pemphigoid (MMP), and pemphigus vulgaris (PV). Serum autoantibodies including antigastric parietal cell antibody (GPCA), antithyroglobulin antibody (TGA), and antithyroid microsomal antibody (TMA) were measured in 500 patients with DG, 287 EOLP without DG (EOLP/DG - ) patients, and 100 healthy control subjects. The 500 patients with DG were diagnosed as having EOLP in 455 (91%), PV in 40 (8%), and MMP in five (1%) patients. We found that 37.0%, 43.6%, and 42.6% of 500 patients with DG, 39.6%, 46.4%, and 45.1% of 455 EOLP with DG (EOLP/DG) patients, and 18.5%, 27.5%, and 30.3% of 287 EOLP/DG - patients had the presence of GPCA, TGA, and TMA in their sera, respectively. DG, EOLP/DG, and EOLP/DG - patients all had a significantly higher frequency of GPCA, TGA, or TMA positivity than healthy control subjects (all P-values < 0.001). Moreover, 455 EOLP/DG patients had a significantly higher frequency of GPCA, TGA, or TMA positivity than 287 EOLP/DG - patients (all P-values < 0.001). Of 210 TGA/TMA-positive patients with DG whose serum thyroid-stimulating hormone (TSH) levels were measured, 84.3%, 6.7%, and 9.0% patients had normal, lower, and higher serum TSH levels, respectively. We conclude that 73.4% DG, 77.1% EOLP/DG, and 47.4% EOLP/DG - patients may have GPCA/TGA/TMA positivity in their sera. Because part of GPCA-positive patients may develop pernicious anemia, autoimmune atrophic gastritis, and gastric carcinoma, and part of TGA/TMA-positive patients may have thyroid dysfunction, these patients should be referred to medical department for further management. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

First Principles Study on the CO Oxidation on Mn-Embedded Divacancy Graphene

PubMed Central

Jiang, Quanguo; Zhang, Jianfeng; Ao, Zhimin; Huang, Huajie; He, Haiyan; Wu, Yuping

2018-01-01

The CO oxidation mechanism on graphene with divacancy (DG) embedded with transition metal from Sc to Zn has been studied by using first principles calculations. The results indicate that O2 molecule is preferentially adsorbed on Sc, Ti, V, Cr, Mn, and Fe-DG, which can avoid the CO poisoning problem that many catalysts facing and is beneficial to the CO oxidation progress. Further study indicates that Mn-DG shows the best catalytic properties for CO oxidation with consideration of both Langmuir-Hinshelwood (LH) and Eley-Rideal (ER) oxidation mechanisms. Along the ER mechanism, the reaction energy barrier for the first step (CO free + O2 pre-adsorbed → OOCO) is 0.96 eV. Along the LH mechanism, the energy barrier for the rate limiting step (CO adsorbed + O2 adsorbed → OOCO) is only 0.41 eV, indicating that the CO oxidation on Mn-DG will occur along LH mechanism. The Hirshfeld charge distributions of O2 and CO molecules is tuned by the embedded Mn atom, and the charge transfer from the embedded Mn atom to the adsorbed molecules plays an important role for the CO oxidation. The result shows that the Mn-embedded divacancy graphene is a noble-metal free and efficient catalyst for CO oxidation at low temperature.

76 FR 23169 - Airworthiness Directives; DG Flugzeugbau GmbH Glaser-Dirks Model DG-808C Gliders

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-26

... Directives; DG Flugzeugbau GmbH Glaser-Dirks Model DG-808C Gliders AGENCY: Federal Aviation Administration... applies to DG Flugzeugbau GmbH Glaser-Dirks Models DG-808C gliders, serial numbers 8-316 B 216 X 1 through...

78 FR 67013 - Airworthiness Directives; DG Flugzeugbau GmbH Gliders

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-08

... Airworthiness Directives; DG Flugzeugbau GmbH Gliders AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... Flugzeugbau GmbH Models DG-800A, DG-800B, DG-500MB gliders. This AD results from mandatory continuing... holidays. For service information identified in this AD, contact DG- Flugzeugbau GmbH, 76646 Bruchsal...

77 FR 2234 - Airworthiness Directives; DG Flugzeugbau GmbH Gliders

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-17

... Airworthiness Directives; DG Flugzeugbau GmbH Gliders AGENCY: Federal Aviation Administration (FAA), Department... new airworthiness directive (AD) for DG Flugzeugbau GmbH Models DG-500 Elan Orion, DG-500 Elan Trainer... DG- Flugzeugbau GmbH, Otto-Lilienthal-Weg 2, 76646 Bruchsal, Federal Republic of Germany; telephone...

Clinicopathological features of growth hormone-producing pituitary adenomas: difference among various types defined by cytokeratin distribution pattern including a transitional form.

PubMed

Obari, Abdulkader; Sano, Toshiaki; Ohyama, Kenichi; Kudo, Eiji; Qian, Zhi Rong; Yoneda, Akiko; Rayhan, Nasim; Mustafizur Rahman, Muhammad; Yamada, Shozo

2008-01-01

Pituitary adenomas producing almost exclusively growth hormones (GH) have been ultrastructurally classified into two distinct types: densely granulated somatotroph (DG) adenomas and sparsely granulated (SG) adenomas. Fibrous body (FB), an intracytoplasmic globular aggregation of cytokeratin (CK) filaments, is a hallmark of SG adenomas. Under light microscope, FB could be identified by CK immunohistochemistry as a dot-pattern immunoreaction versus a perinuclear pattern for cells without FB. However, it has been noted that numerous adenomas contain mixed populations of the two patterns. To clarify clinicopathological characteristics of the adenomas with mixed populations ("intermediate type" adenomas) and to confirm clinicopathological differences between strictly defined DG-type and SG-type adenomas, we performed this study on 104 GH cell adenomas. Having segregated "intermediate-type" adenomas (26 cases), we found significant differences between typical DG-type (47 cases) and SG-type adenomas (31 cases); SG-type adenomas had younger ages (44 vs. 50), higher frequency of macroadenomas (86% vs. 58%), invasiveness (65% vs. 38%), advanced grades (3 or 4) in Knosp's classification (50% vs. 24%), and weaker immunoreaction for GH, beta-TSH, alpha-subunit, E-cadherin, and beta-catenin. Clinicopathological characteristics of "intermediate-type" adenomas were identical to those of DG-type adenomas. These findings confirm that SG-type adenoma is a distinct section of GH cell adenomas with special properties and biological behavior, and suggest that intermediate-phenotype adenomas are enrolled in DG-type adenomas. Special properties and biological behavior of SG-type adenomas may appear after the majority of tumor cells possess a fully developed fibrous body.

Presynaptic dystroglycan-pikachurin complex regulates the proper synaptic connection between retinal photoreceptor and bipolar cells.

PubMed

Omori, Yoshihiro; Araki, Fumiyuki; Chaya, Taro; Kajimura, Naoko; Irie, Shoichi; Terada, Koji; Muranishi, Yuki; Tsujii, Toshinori; Ueno, Shinji; Koyasu, Toshiyuki; Tamaki, Yasuhiro; Kondo, Mineo; Amano, Shiro; Furukawa, Takahisa

2012-05-02

Dystroglycan (DG) is a key component of the dystrophin-glycoprotein complex (DGC) at the neuromuscular junction postsynapse. In the mouse retina, the DGC is localized at the presynapse of photoreceptor cells, however, the function of presynaptic DGC is poorly understood. Here, we developed and analyzed retinal photoreceptor-specific DG conditional knock-out (DG CKO) mice. We found that the DG CKO retina showed a reduced amplitude and a prolonged implicit time of the ERG b-wave. Electron microscopic analysis revealed that bipolar dendrite invagination into the photoreceptor terminus is perturbed in the DG CKO retina. In the DG CKO retina, pikachurin, a DG ligand in the retina, is markedly decreased at photoreceptor synapses. Interestingly, in the Pikachurin(-/-) retina, the DG signal at the ribbon synaptic terminus was severely reduced, suggesting that pikachurin is required for the presynaptic accumulation of DG at the photoreceptor synaptic terminus, and conversely DG is required for pikachurin accumulation. Furthermore, we found that overexpression of pikachurin induces formation and clustering of a DG-pikachurin complex on the cell surface. The Laminin G repeats of pikachurin, which are critical for its oligomerization and interaction with DG, were essential for the clustering of the DG-pikachurin complex as well. These results suggest that oligomerization of pikachurin and its interaction with DG causes DG assembly on the synapse surface of the photoreceptor synaptic terminals. Our results reveal that the presynaptic interaction of pikachurin with DG at photoreceptor terminals is essential for both the formation of proper photoreceptor ribbon synaptic structures and normal retinal electrophysiology.

Diversity and distribution of catechol 2, 3-dioxygenase genes in surface sediments of the Bohai Sea.

PubMed

He, Peiqing; Li, Li; Liu, Jihua; Bai, Yazhi; Fang, Xisheng

2016-05-01

Catechol 2, 3-dioxygenase (C23O) is the key enzyme for aerobic aromatic degradation. Based on clone libraries and quantitative real-time polymerase chain reaction, we characterized diversity and distribution patterns of C23O genes in surface sediments of the Bohai Sea. The results showed that sediments of the Bohai Sea were dominated by genes related to C23O subfamily I.2.A. The samples from wastewater discharge area (DG) and aquaculture farm (KL) showed distinct composition of C23O genes when compared to the samples from Bohai Bay (BH), and total organic carbon was a crucial determinant accounted for the composition variation. C6BH12-38 and C2BH2-35 displayed the highest gene copies and highest ratios to the 16S rRNA genes in KL, and they might prefer biologically labile aromatic hydrocarbons via aquaculture inputs. Meanwhile, C7BH3-48 showed the highest gene copies and highest ratios to the 16S rRNA genes in DG, and this could be selective effect of organic loadings from wastewater discharge. An evident increase in C6BH12-38 and C7BH3-48 gene copies and reduction in diversity of C23O genes in DG and KL indicated composition perturbations of C23O genes and potential loss in functional redundancy. We suggest that ecological habitat and trophic specificity could shape the distribution of C23O genes in the Bohai Sea sediments. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Chrysanthemum WRKY gene DgWRKY5 enhances tolerance to salt stress in transgenic chrysanthemum.

PubMed

Liang, Qian-Yu; Wu, Yin-Huan; Wang, Ke; Bai, Zhen-Yu; Liu, Qing-Lin; Pan, Yuan-Zhi; Zhang, Lei; Jiang, Bei-Bei

2017-07-06

WRKY transcription factors play important roles in plant growth development, resistance and substance metabolism regulation. However, the exact function of the response to salt stress in plants with specific WRKY transcription factors remains unclear. In this research, we isolated a new WRKY transcription factor DgWRKY5 from chrysanthemum. DgWRKY5 contains two WRKY domains of WKKYGQK and two C 2 H 2 zinc fingers. The expression of DgWRKY5 in chrysanthemum was up-regulated under various treatments. Meanwhile, we observed higher expression levels in the leaves contrasted with other tissues. Under salt stress, the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) enzymes in transgenic chrysanthemum were significantly higher than those in WT, whereas the accumulation of H 2 O 2 , O 2 - and malondialdehyde (MDA) was reduced in transgenic chrysanthemum. Several parameters including root length, root length, fresh weight, chlorophyll content and leaf gas exchange parameters in transgenic chrysanthemum were much better compared with WT under salt stress. Moreover, the expression of stress-related genes DgAPX, DgCAT, DgNCED3A, DgNCED3B, DgCuZnSOD, DgP5CS, DgCSD1 and DgCSD2 was up-regulated in DgWRKY5 transgenic chrysanthemum compared with that in WT. These results suggested that DgWRKY5 could function as a positive regulator of salt stress in chrysanthemum.

Short- and long-term cytotoxic effects of doxorubicin conjugates with dendrimers and vector protein on MCF-7/MDR1 chemoresistant breast cancer cells

NASA Astrophysics Data System (ADS)

Zamulaeva, I. A.; Matchuk, O. N.; Churyukina, K. A.; Kudryavtzev, V. A.; Yabbarov, N. G.; Nikolskaya, E. D.; Zhunina, O. A.; Kondrasheva, I. G.; Severin, E. S.

2017-09-01

The dendritic polymers (dendrimers) are perspective nanocontainers for targeted transport of anticancer drugs to tumor cells. We used polyamidoamine dendrimers of the second generation (G2) covalently conjugated with doxorubicin (Dox) and vector protein - recombinant third domain (3D) of alpha-fetoprotein. The objects of the study were MCF-7/MDR1 breast cancer cells, which demonstrated resistance to traditional anticancer agents due to high expression of P-glycoprotein. Effects of free Dox, G2 dendrimers loaded with Dox (G2-Dox), or conjugates of dendrimers with the vector protein and Dox (3D-G2-Dox) were assessed by the criteria of surviving cell number and clonogenic activity 24 hours and 11 days after treatment with the agents at Dox concentration of 2.5 μM, correspondingly. Flow cytometry was used to evaluate accumulation of Dox immediately after the treatment with the agents and removal of Dox during 24 hours of incubation in agent-free medium following by the treatment. Intracellular localization of Dox was studied using laser scanning microscopy. 3D-G2-Dox demonstrated the highest accumulation and the weakest removal from the cells in comparison with all other agents. The use of free Dox, G2-Dox, or 3D-G2-Dox resulted in a significant decrease in number of surviving cells by approximately 25-30% compared to the control (p ≤ 0.01). However, the most pronounced decrease in the clonogenic ability of cells was observed in the 3D-G2-Dox group (to 19% compared to the control, p < 0.01). Taking into account the previously obtained data on the extremely low 3D-G2-Dox accumulation in normal cells, it can be concluded that further development of 3D-G2-Dox as a possible anticancer drug is a promising way to overcome multiple drug resistance with minimal impact on normal cells.

Delayed Gratification Habitable Zones (DG-HZs): When Deep Outer Solar System Regions Become Balmy During Post-Main Sequence Stellar Evolution

NASA Astrophysics Data System (ADS)

Stern, S. A.

2002-09-01

Late in the Sun's evolution it, like all low and moderate mass stars, it will burn as a red giant, generating 1000s of solar luminosities for a few tens of millions of years. A dozen years ago this stage of stellar evolution was predicted to create observable sublimation signatures in systems where Kuiper Belts (KBs) are extant (Stern et al. 1990, Nature, 345, 305); recently, the SWAS spacecraft detected such systems (Melnick et al. 2001, 412, 160). During the red giant phase, the habitable zone of our solar system will lie in the region where Triton, Pluto-Charon, and KBOs orbit. Compared to the 1 AU habitable zone where Earth resided early in the solar system's history, this "delayed gratification habitable zone (DG-HZ)" will enjoy a far less biologically hazardous environment-- with far lower harmful UV radiation levels from the Sun, and a far quieter collisional environment. Objects like Triton, Pluto-Charon, and KBOs, which are known to be rich in both water and organics, will then become possible sites for biochemical and perhaps even biological evolution. The Sun's DG-HZ may only be of academic interest owing to its great separation from us in time. However, several 108 approximately solar-type Milky Way stars burn as luminous red giants today. Thus, if icy-organic objects are common in the 20-50 AU zones of these stars, as they are in our solar system (and as inferred in numerous main sequence stellar disk systems), then DG-HZs form a kind of niche habitable zone that is likely to be numerically common in the galaxy. I will show the calculated temporal evolution of DG-HZs around various stellar types using modern stellar evolution luminosity tracks, and then discuss various aspects of DG-HZs, including the effects of stellar pulsations and mass loss winds. This work was supported by NASA's Origins of Solar Systems Program.

Chemistry and Biology of DNA Containing 1,N2-Deoxyguanosine Adducts of the α,β-Unsaturated Aldehydes Acrolein, Crotonaldehyde, and 4-Hydroxynonenal

PubMed Central

2009-01-01

The α,β-unsaturated aldehydes (enals) acrolein, crotonaldehyde, and trans-4-hydroxynonenal (4-HNE) are products of endogenous lipid peroxidation, arising as a consequence of oxidative stress. The addition of enals to dG involves Michael addition of the N2-amine to give N2-(3-oxopropyl)-dG adducts, followed by reversible cyclization of N1 with the aldehyde, yielding 1,N2-dG exocyclic products. The 1,N2-dG exocyclic adducts from acrolein, crotonaldehyde, and 4-HNE exist in human and rodent DNA. The enal-induced 1,N2-dG lesions are repaired by the nucleotide excision repair pathway in both Escherichia coli and mammalian cells. Oligodeoxynucleotides containing structurally defined 1,N2-dG adducts of acrolein, crotonaldehyde, and 4-HNE were synthesized via a postsynthetic modification strategy. Site-specific mutagenesis of enal adducts has been carried out in E. coli and various mammalian cells. In all cases, the predominant mutations observed are G→T transversions, but these adducts are not strongly miscoding. When placed into duplex DNA opposite dC, the 1,N2-dG exocyclic lesions undergo ring opening to the corresponding N2-(3-oxopropyl)-dG derivatives. Significantly, this places a reactive aldehyde in the minor groove of DNA, and the adducted base possesses a modestly perturbed Watson−Crick face. Replication bypass studies in vitro indicate that DNA synthesis past the ring-opened lesions can be catalyzed by pol η, pol ι, and pol κ. It also can be accomplished by a combination of Rev1 and pol ζ acting sequentially. However, efficient nucleotide insertion opposite the 1,N2-dG ring-closed adducts can be carried out only by pol ι and Rev1, two DNA polymerases that do not rely on the Watson−Crick pairing to recognize the template base. The N2-(3-oxopropyl)-dG adducts can undergo further chemistry, forming interstrand DNA cross-links in the 5′-CpG-3′ sequence, intrastrand DNA cross-links, or DNA−protein conjugates. NMR and mass spectrometric analyses indicate that the DNA interstand cross-links contain a mixture of carbinolamine and Schiff base, with the carbinolamine forms of the linkages predominating in duplex DNA. The reduced derivatives of the enal-mediated N2-dG:N2-dG interstrand cross-links can be processed in mammalian cells by a mechanism not requiring homologous recombination. Mutations are rarely generated during processing of these cross-links. In contrast, the reduced acrolein-mediated N2-dG peptide conjugates can be more mutagenic than the corresponding monoadduct. DNA polymerases of the DinB family, pol IV in E. coli and pol κ in human, are implicated in error-free bypass of model acrolein-mediated N2-dG secondary adducts, the interstrand cross-links, and the peptide conjugates. PMID:19397281

Transition-state destabilization reveals how human DNA polymerase β proceeds across the chemically unstable lesion N7-methylguanine

PubMed Central

Ouzon-Shubeita, Hala; Lee, Seongmin

2014-01-01

N7-Methyl-2′-deoxyguanosine (m7dG) is the predominant lesion formed by methylating agents. A systematic investigation on the effect of m7dG on DNA replication has been difficult due to the chemical instability of m7dG. To gain insights into the m7dG effect, we employed a 2′-fluorine-mediated transition-state destabilzation strategy. Specifically, we determined kinetic parameters for dCTP insertion opposite a chemically stable m7dG analogue, 2′-fluoro-m7dG (Fm7dG), by human DNA polymerase β (polβ) and solved three X-ray structures of polβ in complex with the templating Fm7dG paired with incoming dCTP or dTTP analogues. The kinetic studies reveal that the templating Fm7dG slows polβ catalysis ∼300-fold, suggesting that m7dG in genomic DNA may impede replication by some DNA polymerases. The structural analysis reveals that Fm7dG forms a canonical Watson–Crick base pair with dCTP, but metal ion coordination is suboptimal for catalysis in the polβ-Fm7dG:dCTP complex, which partially explains the slow insertion of dCTP opposite Fm7dG by polβ. In addition, the polβ-Fm7dG:dTTP structure shows open protein conformations and staggered base pair conformations, indicating that N7-methylation of dG does not promote a promutagenic replication. Overall, the first systematic studies on the effect of m7dG on DNA replication reveal that polβ catalysis across m7dG is slow, yet highly accurate. PMID:24966350

Do Brief Motivational Interventions Reduce Drinking Game Frequency in Mandated Students? An analysis of data from two randomized controlled trials

PubMed Central

Fernandez, Anne C.; Yurasek, Allison M.; Merrill, Jennifer E.; Miller, Mary Beth; Zamboanga, Byron L.; Carey, Kate B.; Borsari, Brian

2016-01-01

Purpose College students frequently engage in drinking games (DG) and experience a variety of consequences as a result. It is currently unknown whether brief motivational interventions (BMI) that provide feedback on DG participation can reduce this high risk behavior. This study examined outcome data from two randomized clinical trials to examine whether BMIs facilitate change in DG frequency and how these changes may occur. Methods Mandated college students (Trial 1, N = 198, 46% female; Trial 2, N = 412; 32% female) were randomized to BMI or comparison control conditions. Hierarchical linear modeling (HLM) was used to compare the BMI and comparison groups to determine whether the BMI reduced DG participation over time. Percent change talk (PCT) during the discussion of DG during the session was examined as a predictor of change in DG frequency, and gender was examined as a moderator of treatment effects. Results Controlling for regular drinking frequency, participants who received a BMI did not significantly reduce their DG frequency relative to the comparison group in either sample, and the BMI was equally ineffective at reducing DG behavior for men and women. DG-related PCT during the BMI was associated with lower DG frequency at the second follow-up in both Trials. In Trial 1, PCT during the BMI was associated with less steep increases in DG frequency across the course of all follow-ups. Effects of PCT on DG behavior were not moderated by gender. Conclusions Findings did not support hypothesized reductions in DG participation following a BMI. Future research should explore whether targeted DG-specific interventions could reduce DG participation and the role of in-session client language in facilitating such change. PMID:27936818

10 AU scale halo structure around DG Tauri

NASA Technical Reports Server (NTRS)

Chen, Wen P.; Howell, R. R.; Simon, M.; Benson, J. A.

1992-01-01

Lunar occultation observations of the active T Tauri star DG Tau show that in the infrared K band it has a core-halo structure: 20-25 percent of the flux comes from a region 10 AU in extent and the rest from an unresolved core smaller than an AU. These results are consistent with those reported by Leinert et al. from a separate observation. The results obtained here and those of Leinert et al., measuring the intensity distribution projected along directions spanning roughly 40 deg, indicate that the resolved structure is not highly elongated. The extended emission is interpreted as star light scattered by optically thin dust located in a halo surrounding the star.

Space-time adaptive solution of inverse problems with the discrete adjoint method

NASA Astrophysics Data System (ADS)

Alexe, Mihai; Sandu, Adrian

2014-08-01

This paper develops a framework for the construction and analysis of discrete adjoint sensitivities in the context of time dependent, adaptive grid, adaptive step models. Discrete adjoints are attractive in practice since they can be generated with low effort using automatic differentiation. However, this approach brings several important challenges. The space-time adjoint of the forward numerical scheme may be inconsistent with the continuous adjoint equations. A reduction in accuracy of the discrete adjoint sensitivities may appear due to the inter-grid transfer operators. Moreover, the optimization algorithm may need to accommodate state and gradient vectors whose dimensions change between iterations. This work shows that several of these potential issues can be avoided through a multi-level optimization strategy using discontinuous Galerkin (DG) hp-adaptive discretizations paired with Runge-Kutta (RK) time integration. We extend the concept of dual (adjoint) consistency to space-time RK-DG discretizations, which are then shown to be well suited for the adaptive solution of time-dependent inverse problems. Furthermore, we prove that DG mesh transfer operators on general meshes are also dual consistent. This allows the simultaneous derivation of the discrete adjoint for both the numerical solver and the mesh transfer logic with an automatic code generation mechanism such as algorithmic differentiation (AD), potentially speeding up development of large-scale simulation codes. The theoretical analysis is supported by numerical results reported for a two-dimensional non-stationary inverse problem.

Ammonium Ion Binding to DNA G-Quadruplexes: Do Electrospray Mass Spectra Faithfully Reflect the Solution-Phase Species?

NASA Astrophysics Data System (ADS)

Balthasart, Françoise; Plavec, Janez; Gabelica, Valérie

2013-01-01

G-quadruplex nucleic acids can bind ammonium ions in solution, and these complexes can be detected by electrospray mass spectrometry (ESI-MS). However, because ammonium ions are volatile, the extent to which ESI-MS quantitatively could provide an accurate reflection of such solution-phase equilibria is unclear. Here we studied five G-quadruplexes having known solution-phase structure and ammonium ion binding constants: the bimolecular G-quadruplexes (dG4T4G4)2, (dG4T3G4)2, and (dG3T4G4)2, and the intramolecular G-quadruplexes dG4(T4G4)3 and dG2T2G2TGTG2T2G2 (thrombin binding aptamer). We found that not all mass spectrometers are equally suited to reflect the solution phase species. Ion activation can occur in the electrospray source, or in a high-pressure traveling wave ion mobility cell. When the softest instrumental conditions are used, ammonium ions bound between G-quartets, but also additional ammonium ions bound at specific sites outside the external G-quartets, can be observed. However, even specifically bound ammonium ions are in some instances too labile to be fully retained in the gas phase structures, and although the ammonium ion distribution observed by ESI-MS shows biases at specific stoichiometries, the relative abundances in solution are not always faithfully reflected. Ion mobility spectrometry results show that all inter-quartet ammonium ions are necessary to preserve the G-quadruplex fold in the gas phase. Ion mobility experiments, therefore, help assign the number of inner ammonium ions in the solution phase structure.[Figure not available: see fulltext.

77 FR 2236 - Airworthiness Directives; DG Flugzeugbau GmbH Sailplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-17

...H Sailplanes AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT... are revising an earlier NPRM for DG Flugzeugbau GmbH DG-500 Elan series sailplanes and Models DG-500M... information identified in this proposed AD, DG Flugzeugbau GmbH, Otto-Lilienthal-Weg 2, 76646 Bruchsal...

A dystroglycan mutation (p.Cys667Phe) associated to muscle-eye-brain disease with multicystic leucodystrophy results in ER-retention of the mutant protein.

PubMed

Signorino, Giulia; Covaceuszach, Sonia; Bozzi, Manuela; Hübner, Wolfgang; Mönkemöller, Viola; Konarev, Petr V; Cassetta, Alberto; Brancaccio, Andrea; Sciandra, Francesca

2018-02-01

Dystroglycan (DG) is a cell adhesion complex composed by two subunits, the highly glycosylated α-DG and the transmembrane β-DG. In skeletal muscle, DG is involved in dystroglycanopathies, a group of heterogeneous muscular dystrophies characterized by a reduced glycosylation of α-DG. The genes mutated in secondary dystroglycanopathies are involved in the synthesis of O-mannosyl glycans and in the O-mannosylation pathway of α-DG. Mutations in the DG gene (DAG1), causing primary dystroglycanopathies, destabilize the α-DG core protein influencing its binding to modifying enzymes. Recently, a homozygous mutation (p.Cys699Phe) hitting the β-DG ectodomain has been identified in a patient affected by muscle-eye-brain disease with multicystic leucodystrophy, suggesting that other mechanisms than hypoglycosylation of α-DG could be implicated in dystroglycanopathies. Herein, we have characterized the DG murine mutant counterpart by transfection in cellular systems and high-resolution microscopy. We observed that the mutation alters the DG processing leading to retention of its uncleaved precursor in the endoplasmic reticulum. Accordingly, small-angle X-ray scattering data, corroborated by biochemical and biophysical experiments, revealed that the mutation provokes an alteration in the β-DG ectodomain overall folding, resulting in disulfide-associated oligomerization. Our data provide the first evidence of a novel intracellular mechanism, featuring an anomalous endoplasmic reticulum-retention, underlying dystroglycanopathy. © 2017 Wiley Periodicals, Inc.

Novel optimization technique of isolated microgrid with hydrogen energy storage.

PubMed

Beshr, Eman Hassan; Abdelghany, Hazem; Eteiba, Mahmoud

2018-01-01

This paper presents a novel optimization technique for energy management studies of an isolated microgrid. The system is supplied by various Distributed Energy Resources (DERs), Diesel Generator (DG), a Wind Turbine Generator (WTG), Photovoltaic (PV) arrays and supported by fuel cell/electrolyzer Hydrogen storage system for short term storage. Multi-objective optimization is used through non-dominated sorting genetic algorithm to suit the load requirements under the given constraints. A novel multi-objective flower pollination algorithm is utilized to check the results. The Pros and cons of the two optimization techniques are compared and evaluated. An isolated microgrid is modelled using MATLAB software package, dispatch of active/reactive power, optimal load flow analysis with slack bus selection are carried out to be able to minimize fuel cost and line losses under realistic constraints. The performance of the system is studied and analyzed during both summer and winter conditions and three case studies are presented for each condition. The modified IEEE 15 bus system is used to validate the proposed algorithm.

Novel optimization technique of isolated microgrid with hydrogen energy storage

PubMed Central

Abdelghany, Hazem; Eteiba, Mahmoud

2018-01-01

This paper presents a novel optimization technique for energy management studies of an isolated microgrid. The system is supplied by various Distributed Energy Resources (DERs), Diesel Generator (DG), a Wind Turbine Generator (WTG), Photovoltaic (PV) arrays and supported by fuel cell/electrolyzer Hydrogen storage system for short term storage. Multi-objective optimization is used through non-dominated sorting genetic algorithm to suit the load requirements under the given constraints. A novel multi-objective flower pollination algorithm is utilized to check the results. The Pros and cons of the two optimization techniques are compared and evaluated. An isolated microgrid is modelled using MATLAB software package, dispatch of active/reactive power, optimal load flow analysis with slack bus selection are carried out to be able to minimize fuel cost and line losses under realistic constraints. The performance of the system is studied and analyzed during both summer and winter conditions and three case studies are presented for each condition. The modified IEEE 15 bus system is used to validate the proposed algorithm. PMID:29466433

Integration of a molten carbonate fuel cell with a direct exhaust absorption chiller

NASA Astrophysics Data System (ADS)

Margalef, Pere; Samuelsen, Scott

A high market value exists for an integrated high-temperature fuel cell-absorption chiller product throughout the world. While high-temperature, molten carbonate fuel cells are being commercially deployed with combined heat and power (CHP) and absorption chillers are being commercially deployed with heat engines, the energy efficiency and environmental attributes of an integrated high-temperature fuel cell-absorption chiller product are singularly attractive for the emerging distributed generation (DG) combined cooling, heating, and power (CCHP) market. This study addresses the potential of cooling production by recovering and porting the thermal energy from the exhaust gas of a high-temperature fuel cell (HTFC) to a thermally activated absorption chiller. To assess the practical opportunity of serving an early DG-CCHP market, a commercially available direct fired double-effect absorption chiller is selected that closely matches the exhaust flow and temperature of a commercially available HTFC. Both components are individually modeled, and the models are then coupled to evaluate the potential of a DG-CCHP system. Simulation results show that a commercial molten carbonate fuel cell generating 300 kW of electricity can be effectively coupled with a commercial 40 refrigeration ton (RT) absorption chiller. While the match between the two "off the shelf" units is close and the simulation results are encouraging, the match is not ideal. In particular, the fuel cell exhaust gas temperature is higher than the inlet temperature specified for the chiller and the exhaust flow rate is not sufficient to achieve the potential heat recovery within the chiller heat exchanger. To address these challenges, the study evaluates two strategies: (1) blending the fuel cell exhaust gas with ambient air, and (2) mixing the fuel cell exhaust gases with a fraction of the chiller exhaust gas. Both cases are shown to be viable and result in a temperature drop and flow rate increase of the gases before the chiller inlet. The results show that no risk of cold end corrosion within the chiller heat exchanger exists. In addition, crystallization is not an issue during system operation. Accounting for the electricity and the cooling produced and disregarding the remaining thermal energy, the second strategy is preferred and yields an overall estimated efficiency of 71.7%.

Memory retrieval-induced activation of adult-born neurons generated in response to damage to the dentate gyrus.

PubMed

Aguilar-Arredondo, Andrea; Zepeda, Angélica

2018-07-01

The dentate gyrus (DG) is a neurogenic structure that exhibits functional and structural reorganization after injury. Neurogenesis and functional recovery occur after brain damage, and the possible relation between both processes is a matter of study. We explored whether neurogenesis and the activation of new neurons correlated with DG recovery over time. We induced a DG lesion in young adult rats through the intrahippocampal injection of kainic acid and analyzed functional recovery and the activation of new neurons after animals performed a contextual fear memory task (CFM) or a control spatial exploratory task. We analyzed the number of BrdU+ cells that co-localized with doublecortin (DCX) or with NeuN within the damaged DG and evaluated the number of cells in each population that were labelled with the activity marker c-fos after either task. At 10 days post-lesion (dpl), a region of the granular cell layer was devoid of cells, evidencing the damaged area, whereas at 30 dpl this region was significantly smaller. At 10 dpl, the number of BrdU+/DCX+/c-fos positive cells was increased compared to the sham-lesion group, but CFM was impaired. At 30 dpl, a significantly greater number of BrdU+/NeuN+/c-fos positive cells was observed than at 10 dpl, and activation correlated with CFM recovery. Performance in the spatial exploratory task induced marginal c-fos immunoreactivity in the BrdU+/NeuN+ population. We demonstrate that neurons born after the DG was damaged survive and are activated in a time- and task-dependent manner and that activation of new neurons occurs along functional recovery.

Breast fine-needle aspiration malondialdehyde deoxyguanosine adduct in breast cancer

PubMed Central

Peluso, Marco; Munnia, Armelle; Risso, Gabriella G.; Catarzi, Sandra; Piro, Sara; Ceppi, Marcello; Giese, Roger W.; Brancato, Beniamino

2012-01-01

This study has analysed the generation of 3-(2-deoxy-β-D-erythro-pentafuranosyl) pyrimido [1,2-α] purin-10 (3H)-one deoxyguanosine adduct [M1dG], a biomarker of oxidative stress and lipid peroxidation, in breast fine-needle aspirate samples of 22 patients with breast cancer, at different clinical stages, in respect to 13 controls. The multivariate analysis show that M1dG adduct was higher in cases than in controls (Mean Ratio (MR) = 5.26, 95% CI = 3.16–8.77). Increased M1dG was observed in women with a tumour grade 3 and a pathological diameter 2 (MR = 7.61, 95% CI 3.91–14.80 and MR = 5.75, 95% CI = 3.13–10.59, respectively). A trend with increasing tumour grade and pathological diameter was present (MR = 1.98, 95% CI = 1.57–2.50 and MR = 2.44, 95% CI = 1.71–3.48, respectively). Not significant effects of age and smoking habit were found (MR = 1.58, 95% CI = 0.92–2.72 and MR = 1.68, 95% CI 0.88–3.20, respectively). An increment over the background frequency of M1dG can contribute to breast cancer development. Increasing severity of breast tumour can influence DNA damage level. PMID:21250785

Advanced Discontinuous Galerkin Algorithms and First Open-Field Line Turbulence Simulations

NASA Astrophysics Data System (ADS)

Hammett, G. W.; Hakim, A.; Shi, E. L.

2016-10-01

New versions of Discontinuous Galerkin (DG) algorithms have interesting features that may help with challenging problems of higher-dimensional kinetic problems. We are developing the gyrokinetic code Gkeyll based on DG. DG also has features that may help with the next generation of Exascale computers. Higher-order methods do more FLOPS to extract more information per byte, thus reducing memory and communications costs (which are a bottleneck at exascale). DG uses efficient Gaussian quadrature like finite elements, but keeps the calculation local for the kinetic solver, also reducing communication. Sparse grid methods might further reduce the cost significantly in higher dimensions. The inner product norm can be chosen to preserve energy conservation with non-polynomial basis functions (such as Maxwellian-weighted bases), which can be viewed as a Petrov-Galerkin method. This allows a full- F code to benefit from similar Gaussian quadrature as used in popular δf gyrokinetic codes. Consistent basis functions avoid high-frequency numerical modes from electromagnetic terms. We will show our first results of 3 x + 2 v simulations of open-field line/SOL turbulence in a simple helical geometry (like Helimak/TORPEX), with parameters from LAPD, TORPEX, and NSTX. Supported by the Max-Planck/Princeton Center for Plasma Physics, the SciDAC Center for the Study of Plasma Microturbulence, and DOE Contract DE-AC02-09CH11466.

Terrestrial Gamma Radiation Dose Rate of West Sarawak

NASA Astrophysics Data System (ADS)

Izham, A.; Ramli, A. T.; Saridan Wan Hassan, W. M.; Idris, H. N.; Basri, N. A.

2017-10-01

A study of terrestrial gamma radiation (TGR) dose rate was conducted in west of Sarawak, covering Kuching, Samarahan, Serian, Sri Aman, and Betong divisions to construct a baseline TGR dose rate level data of the areas. The total area covered was 20,259.2 km2, where in-situ measurements of TGR dose rate were taken using NaI(Tl) scintillation detector Ludlum 19 micro R meter NaI(Tl) approximately 1 meter above ground level. Twenty-nine soil samples were taken across the 5 divisions covering 26 pairings of 9 geological formations and 7 soil types. A hyperpure Germanium detector was then used to find the samples' 238U, 232Th, and 40K radionuclides concentrations producing a correction factor Cf = 0.544. A total of239 measured data were corrected with Cf resulting in a mean Dm of 47 ± 1 nGy h-1, with a range between 5 nGy h-1 - 103 nGy h-1. A multiple regression analysis was conducted between geological means and soil types means against the corrected TGR dose rate Dm, generating Dg,s= 0.847Dg+ 0.637Ds- 22.313 prediction model with a normalized Beta equation of Dg,s= 0.605Dg+ 0.395Ds. The model has an 84.6% acceptance of Whitney- Mann test null hypothesis when tested against the corrected TGR dose rates.

Do brief motivational interventions reduce drinking game frequency in mandated students? An analysis of data from two randomized controlled trials.

PubMed

Fernandez, Anne C; Yurasek, Ali M; Merrill, Jennifer E; Miller, Mary Beth; Zamboanga, Byron L; Carey, Kate B; Borsari, Brian

2017-02-01

College students frequently engage in drinking games (DGs) and experience a variety of consequences as a result. It is currently unknown whether brief motivational interventions (BMIs) that provide feedback on DG participation can reduce this high risk behavior. This study examined outcome data from 2 randomized clinical trials to examine whether BMIs facilitate change in DG frequency and how these changes may occur. Mandated college students (Trial 1, N = 198, 46% female; Trial 2, N = 412; 32% female) were randomized to BMI or comparison control conditions. Hierarchical linear modeling (HLM) was used to compare the BMI and comparison groups to determine whether the BMI reduced DG participation over time. Percent change talk (PCT) during the discussion of DG during the session was examined as a predictor of change in DG frequency, and gender was examined as a moderator of treatment effects. Controlling for regular drinking frequency, participants who received a BMI did not significantly reduce their DG frequency relative to the comparison group in either sample, and the BMI was equally ineffective at reducing DG behavior for men and women. DG-related PCT during the BMI was associated with lower DG frequency at the second follow-up in both trials. In Trial 1, PCT during the BMI was associated with less steep increases in DG frequency across the course of all follow-ups. Effects of PCT on DG behavior were not moderated by gender. Findings did not support hypothesized reductions in DG participation following a BMI. Future research should explore whether targeted DG-specific interventions could reduce DG participation and the role of in-session client language in facilitating such change. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A computational model of pattern separation efficiency in the dentate gyrus with implications in schizophrenia

PubMed Central

Faghihi, Faramarz; Moustafa, Ahmed A.

2015-01-01

Information processing in the hippocampus begins by transferring spiking activity of the entorhinal cortex (EC) into the dentate gyrus (DG). Activity pattern in the EC is separated by the DG such that it plays an important role in hippocampal functions including memory. The structural and physiological parameters of these neural networks enable the hippocampus to be efficient in encoding a large number of inputs that animals receive and process in their life time. The neural encoding capacity of the DG depends on its single neurons encoding and pattern separation efficiency. In this study, encoding by the DG is modeled such that single neurons and pattern separation efficiency are measured using simulations of different parameter values. For this purpose, a probabilistic model of single neurons efficiency is presented to study the role of structural and physiological parameters. Known neurons number of the EC and the DG is used to construct a neural network by electrophysiological features of granule cells of the DG. Separated inputs as activated neurons in the EC with different firing probabilities are presented into the DG. For different connectivity rates between the EC and DG, pattern separation efficiency of the DG is measured. The results show that in the absence of feedback inhibition on the DG neurons, the DG demonstrates low separation efficiency and high firing frequency. Feedback inhibition can increase separation efficiency while resulting in very low single neuron’s encoding efficiency in the DG and very low firing frequency of neurons in the DG (sparse spiking). This work presents a mechanistic explanation for experimental observations in the hippocampus, in combination with theoretical measures. Moreover, the model predicts a critical role for impaired inhibitory neurons in schizophrenia where deficiency in pattern separation of the DG has been observed. PMID:25859189

Adaptive Discontinuous Galerkin Methods in Multiwavelets Bases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Archibald, Richard K; Fann, George I; Shelton Jr, William Allison

2011-01-01

We use a multiwavelet basis with the Discontinuous Galerkin (DG) method to produce a multi-scale DG method. We apply this Multiwavelet DG method to convection and convection-diffusion problems in multiple dimensions. Merging the DG method with multiwavelets allows the adaptivity in the DG method to be resolved through manipulation of multiwavelet coefficients rather than grid manipulation. Additionally, the Multiwavelet DG method is tested on non-linear equations in one dimension and on the cubed sphere.

Nanotoxicological and teratogenic effects: A linkage between dendrimer surface charge and zebrafish developmental stages.

PubMed

Calienni, Maria Natalia; Feas, Daniela Agustina; Igartúa, Daniela Edith; Chiaramoni, Nadia Silvia; Alonso, Silvia Del Valle; Prieto, Maria Jimena

2017-12-15

This article reports novel results about nanotoxicological and teratogenic effects of the PAMAM dendrimers DG4 and DG4.5 in zebrafish (Danio rerio). Zebrafish embryos and larvae were used as a rapid, high-throughput, cost-effective whole-animal model. The objective was to provide a more comprehensive and predictive developmental toxicity screening of DG4 and DG4.5 and test the influence of their surface charge. Nanotoxicological and teratogenic effects were assessed at developmental, morphological, cardiac, neurological and hepatic level. The effect of surface charge was determined in both larvae and embryos. DG4 with positive surface charge was more toxic than DG4.5 with negative surface charge. DG4 and DG4.5 induced teratogenic effects in larvae, whereas DG4 also induced lethal effects in both zebrafish embryos and larvae. However, larvae were less sensitive than embryos to the lethal effects of DG4. The platform of assays proposed and data obtained may contribute to the characterization of hazards and differential effects of these nanoparticles. Copyright © 2017 Elsevier Inc. All rights reserved.

Glucose metabolism-weighted imaging with chemical exchange-sensitive MRI of 2-deoxyglucose (2DG) in brain: Sensitivity and biological sources.

PubMed

Jin, Tao; Mehrens, Hunter; Wang, Ping; Kim, Seong-Gi

2016-12-01

Recent proof-of-principle studies have demonstrated the feasibility of measuring the uptake and metabolism of non-labeled 2-deoxy-D-glucose (2DG) by a chemical exchange-sensitive spin-lock (CESL) MRI approach. In order to gain better understanding of this new approach, we performed dynamic in vivo CESL MRI on healthy rat brains with an intravenous injection of 2DG under various conditions at 9.4T. For three 2DG doses of 0.25, 0.5 and 1g/kg, we found that 2DG-CESL signals increased linearly with injection dose at the initial (<20min) but not the later period (>40min) suggesting time-dependent differential weightings of 2DG transport and metabolism. Remaining 2DG-CESL studies were performed with 0.25g/kg 2DG. Since a higher isoflurane level reduces glucose metabolism and increases blood flow, 2DG-CESL was measured under 0.5%, 1.5% and 2.2% isoflurane. The 2DG-CESL signal was reduced at higher isoflurane levels correlating well with the 2DG phosphorylation in the intracellular space. To detect regional heterogeneities of glucose metabolism, 2DG-CESL with 0.33×0.33×1.50mm 3 resolution was obtained, which indeed showed a higher response in the cortex compared to the corpus callosum. Lastly, unlike CESL MRI with the injection of non-transportable mannitol, the 2DG-CESL response decreased with an increased spin-lock pulse power confirming that 2DG-CESL is dominated by chemical exchange processes in the extravascular space. Taken together, our results showed that 2DG-CESL MRI signals mainly indicate glucose transport and metabolism and may be a useful biomarker for metabolic studies of normal and diseased brains. Copyright © 2016 Elsevier Inc. All rights reserved.

α-dystroglycan is a potential target of matrix metalloproteinase MMP-2.

PubMed

Sbardella, Diego; Sciandra, Francesca; Gioia, Magda; Marini, Stefano; Gori, Alessandro; Giardina, Bruno; Tarantino, Umberto; Coletta, Massimo; Brancaccio, Andrea; Bozzi, Manuela

2015-01-01

Dystroglycan (DG) is a member of the glycoprotein complex associated to dystrophin and composed by two subunits, the β-DG, a transmembrane protein, and the α-DG, an extensively glycosylated extracellular protein. The β-DG ectodomain degradation by the matrix metallo-proteinases (i.e., MMP-2 and MMP-9) in both, pathological and physiological conditions, has been characterized in detail in previous publications. Since the amounts of α-DG and β-DG at the cell surface decrease when gelatinases are up-regulated, we investigated the degradation of α-DG subunit by MMP-2. Present data show, for the first time, that the proteolysis of α-DG indeed occurs on a native glycosylated molecule enriched from rabbit skeletal muscle. In order to characterize the α-DG portion, which is more prone to cleavage by MMP-2, we performed different degradations on tailored recombinant domains of α-DG spanning the whole subunit. The overall bulk of results casts light on a relevant susceptibility of the α-DG to MMP-2 degradation with particular reference to its C-terminal domain, thus opening a new scenario on the role of gelatinases (in particular of MMP-2) in the degradation of this glycoprotein complex, taking place in the course of pathological processes. Copyright © 2014. Published by Elsevier B.V.

NMDA receptor hypofunction in the dentate gyrus and impaired context discrimination in adult Fmr1 knockout mice.

PubMed

Eadie, Brennan D; Cushman, Jesse; Kannangara, Timal S; Fanselow, Michael S; Christie, Brian R

2012-02-01

Fragile X syndrome (FXS) is the most common form of inherited intellectual disability in humans. This X-linked disorder is caused by the transcriptional repression of a single gene, Fmr1. The loss of Fmr1 transcription prevents the production of Fragile X mental retardation protein (FMRP) which in turn disrupts the expression of a variety of key synaptic proteins that appear to be important for intellectual ability. A clear link between synaptic dysfunction and behavioral impairment has been elusive, despite the fact that several animal models of FXS have been generated. Here we report that Fmr1 knockout mice exhibit impaired bidirectional synaptic plasticity in the dentate gyrus (DG) of the hippocampus. These deficits are associated with a novel decrease in functional NMDARs (N-methyl-D-aspartate receptors). In addition, mice lacking the Fmr1 gene show impaired performance in a context discrimination task that normally requires functional NMDARs in the DG. These data indicate that Fmr1 deletion results in significant NMDAR-dependent electrophysiological and behavioral impairments specific to the DG. Copyright © 2010 Wiley Periodicals, Inc.

Diacylglycerol-enriched structured lipids containing CLA and capric acid alter body fat mass and lipid metabolism in rats.

PubMed

Kim, Hye-Jin; Lee, Ki-Teak; Lee, Mi-Kyung; Jeon, Seon-Min; Choi, Myung-Sook

2006-01-01

The present study compared the effect of corn oil, diacylglycerol (DG) oil, and DG-enriched structured lipids (SL-DG) produced from corn oil, capric and conjugated linoleic acid on adiposity in rats fed an AIN-76 diet (5% fat) for 6 weeks. The plasma and hepatic lipids, adipose tissue weight, and enzyme activities related to fatty acid metabolism were determined. The weights of the epididymal white adipose tissue (WAT), perirenal WAT, and interscapular WAT were significantly lower in the SL-DG group than in the DG group. Reduction of fat mass in the SL-DG group was related to suppressing fatty acid synthase activities and enhancing beta-oxidation activity in perirenal WAT. The plasma leptin was lower in the SL-DG group than in the DG group, plus a lower plasma TG level was accompanied by an increase in adipocyte LPL activity. Meanwhile the SL-DG supplement lowered the plasma and hepatic cholesterol level. In addition, the hepatic HMG-CoA reductase and ACAT activities were significantly lower in the SL-DG group than in the other groups. The DG-enriched SL used in this study was effective in enhancing triglyceride metabolism in adipose tissue, especially as regards reducing the abdominal fat mass and cholesterol metabolism in the liver. Copyright 2006 S. Karger AG, Basel.

EFFECTIVE ACIDITY CONSTANT BEHAVIOR NEAR ZERO CHARGE CONDITIONS

EPA Science Inventory

Surface site (>SOH group) acidity reactions require expressions of the form: Ka = [>SOHn-1(z-1)]aH+EXP(-DG/RT)/[>SOHnz] (where all variables have their usual meaning). One can rearrange this expression to generate an effective acidity constant historically defined as: Qa = Ka...

Thermal stability study of a new guanidine suppressor for the next-generation caustic-side solvent extraction process

DOE PAGES

Hill, Talon G.; Ensor, Dale D.; Delmau, Lætitia Helene; ...

2016-02-06

Cesium stripping performance of thermally stressed solvent degrades slowly over time in batch tests of the Next Generation Caustic-Side Solvent Extraction (NGS) process. NGS is currently used at pilot scale at the Savannah River Site for the selective removal of cesium from high-level salt waste. Recently a new guanidine, N,N',N" -tris(3,7-dimethyloctyl)guanidine (TiDG), was chosen for use as the suppressor, a lipophilic organic base needed for stripping, and the present study was undertaken to address the question of its stability. The NGS process solvent was evaluated for a period of three months under a variety of temperature and storage conditions. Themore » performance of the solvent was tested at 30-day increments using a standard extraction, scrub, strip, and extraction (ES 2S 3E) sequence. Lastly, the results provide insight on the effects of storage and process conditions, the stripping behavior of TiDG, and the stability of the new solvent composition.« less

Thermal stability study of a new guanidine suppressor for the next-generation caustic-side solvent extraction process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hill, Talon G.; Ensor, Dale D.; Delmau, Lætitia Helene

Cesium stripping performance of thermally stressed solvent degrades slowly over time in batch tests of the Next Generation Caustic-Side Solvent Extraction (NGS) process. NGS is currently used at pilot scale at the Savannah River Site for the selective removal of cesium from high-level salt waste. Recently a new guanidine, N,N',N" -tris(3,7-dimethyloctyl)guanidine (TiDG), was chosen for use as the suppressor, a lipophilic organic base needed for stripping, and the present study was undertaken to address the question of its stability. The NGS process solvent was evaluated for a period of three months under a variety of temperature and storage conditions. Themore » performance of the solvent was tested at 30-day increments using a standard extraction, scrub, strip, and extraction (ES 2S 3E) sequence. Lastly, the results provide insight on the effects of storage and process conditions, the stripping behavior of TiDG, and the stability of the new solvent composition.« less

Inhibition of murine splenic T lymphocyte proliferation by 2-deoxy-D-glucose-induced metabolic stress

NASA Technical Reports Server (NTRS)

Miller, E. S.; Klinger, J. C.; Akin, C.; Koebel, D. A.; Sonnenfeld, G.

1994-01-01

Female Swiss-Webster mice were injected with the glucose analogue 2-deoxy-D-glucose (2-DG), which when administered to rodents induces acute periods of metabolic stress. A single or multiple injections of 2-DG invoked a stress response, as evidenced by increases in serum corticosterone levels. The influence of this metabolic stressor on the blastogenic potential of splenic T lymphocytes was then examined. It was found that one, two, or three injections of 2-DG resulted in depressed T cell proliferative responses, with an attenuation of the effect occurring by the fifth injection. The 2-DG-induced inhibition of T cell proliferation was not attributable to 2-DG-induced cytolysis, as in vitro incubation of naive T cells with varying concentrations of 2-DG did not result in a reduction in cell number or viability, and flow cytometric analysis demonstrated that percentages of CD3, CD4, and CD8 splenic T cells were not altered as a result of 2-DG-induced stress. Incubating naive T cells in varying concentrations of 2-DG resulted in a dose-dependent inhibition of T cell blastogenic potential. Following in vivo exposure to 2-DG, T cell proliferation did not return to normal levels until 3 days after the cessation of 2-DG injections. Administering the beta-adrenergic receptor antagonist propranolol did not reverse the inhibited lymphoproliferation in 2-DG-treated mice. The inhibition in T cell proliferation was not observed, however, in mice that had been adrenalectomized or hypophysectomized and injected with 2-DG.(ABSTRACT TRUNCATED AT 250 WORDS).

Atiyah classes and dg-Lie algebroids for matched pairs

NASA Astrophysics Data System (ADS)

Batakidis, Panagiotis; Voglaire, Yannick

2018-01-01

For every Lie pair (L , A) of algebroids we construct a dg-manifold structure on the Z-graded manifold M = L [ 1 ] ⊕ L / A such that the inclusion ι : A [ 1 ] → M and the projection p : M → L [ 1 ] are morphisms of dg-manifolds. The vertical tangent bundle Tp M then inherits a structure of dg-Lie algebroid over M. When the Lie pair comes from a matched pair of Lie algebroids, we show that the inclusion ι induces a quasi-isomorphism that sends the Atiyah class of this dg-Lie algebroid to the Atiyah class of the Lie pair. We also show how (Atiyah classes of) Lie pairs and dg-Lie algebroids give rise to (Atiyah classes of) dDG-algebras.

Immune Alterations in Male and Female Mice after 2-Deoxy-D-Glucose Administration

NASA Technical Reports Server (NTRS)

Dreau, Didier; Morton, Darla S.; Foster, Mareva; Swiggett, Jeanene P.; Sonnenfeld, Gerald

1995-01-01

Administration of 2-deoxy-D-glucose (2-DG), an analog of glucose which inhibits glycolysis by competitive antagonism for phosphohexose isomerase, results in acute periods of intracellular glucoprivation and hyperglycemia resulting in hyperphagia. In addition to these changes in the carbohydrate metabolism, injection of 2-DG results in alterations of both the endocrine and neurological systems as suggested by modifications in oxytocin and glucocorticoid levels and norepinephrine production. Moreover, alterations of the immune response, such as a decrease in the in vitro proliferation of splenocytes after mitogen-stimulation, were observed in mice injected with 2-DG. Sex, genotype and environment are among the factors that may modulate effects of catecholamines and hypothalamo-pituitary-adrenal axis on these immune changes. Sexual dimorphism in immune function resulting from the effects of sex hormones on immune effector cells has been shown in both animals and humans. These observations have important implications, especially with regard to higher incidence of many autoimmune diseases in females. Evidence exists that reproductive hormones influence the immune system and increase the risk of immunologically related disorders in both animals and humans. Indeed, immunological responses in stressful situations may also be confounded by fluctuations of sex hormones especially in females. Lymphocyte distribution, cytoldne production, and the ability of lymphocyte to proliferate in vitro were analyzed in male and female mice to determine if sex influenced 2-DG immunomodulation. In addition, the influence of hormones, especially sex hormones, on these changes were evaluated.

Development of a liquid chromatography-mass spectrometry based enzyme activity assay for phosphatidylcholine-specific phospholipase C.

PubMed

Murakami, Chiaki; Mizuno, Satoru; Kado, Sayaka; Sakane, Fumio

2017-06-01

Phosphatidylcholine (PC)-specific phospholipase C (PC-PLC) hydrolyzes PC to generate the second messenger 1,2-diacylglycerol (DG) and phosphocholine. PC-PLC plays pivotal roles in inflammation, carcinogenesis, tumor progression, atherogenesis, and subarachnoid hemorrhage. Although the activity of PC-PLC in mammalian tissues was discovered approximately 40 years ago, neither the protein nor its gene has been identified. In the present study, we developed a non-radioactive enzyme activity assay for PC-PLC based on mass spectrometric detection of DG following HPLC separation. This new liquid chromatography-mass spectrometry (LC-MS) assay directly determines a specific reaction product, 1-palmitoyl-2-oleoyl-DG, that is generated from 1-palmitoyl-2-oleoyl-PC by purified Bacillus cereus PC-PLC. The LC-MS assay offers several advantages including a lower background (0.02% versus 91%), higher signal background ratio (4242 versus 1.06)/signal noise ratio (7494 versus 4.4), higher sensitivity (≥32-fold), and lower limit of quantitation (0.04 pmol versus 0.69 pmol of PC-PLC), than a conventional fluorometric assay, which indirectly detects phosphocholine produced in the reaction. In addition to Bacillus cereus PC-PLC, the LC-MS assay was applicable to the measurement of mammalian PC-PLC prepared from the mouse brain. The radioisotope-free, highly sensitive and precise LC-MS assay for PC-PLC would be useful for the purification and identification of PC-PLC protein. Copyright © 2017 Elsevier Inc. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor-Pashow, K.; Fondeur, F.; White, T.

Savannah River National Laboratory (SRNL) was tasked with identifying and developing at least one, but preferably two methods for quantifying the suppressor in the Next Generation Solvent (NGS) system. The suppressor is a guanidine derivative, N,N',N"-tris(3,7-dimethyloctyl)guanidine (TiDG). A list of 10 possible methods was generated, and screening experiments were performed for 8 of the 10 methods. After completion of the screening experiments, the non-aqueous acid-base titration was determined to be the most promising, and was selected for further development as the primary method. {sup 1}H NMR also showed promising results from the screening experiments, and this method was selected formore » further development as the secondary method. Other methods, including {sup 36}Cl radiocounting and ion chromatography, also showed promise; however, due to the similarity to the primary method (titration) and the inability to differentiate between TiDG and TOA (tri-n-ocytlamine) in the blended solvent, {sup 1}H NMR was selected over these methods. Analysis of radioactive samples obtained from real waste ESS (extraction, scrub, strip) testing using the titration method showed good results. Based on these results, the titration method was selected as the method of choice for TiDG measurement. {sup 1}H NMR has been selected as the secondary (back-up) method, and additional work is planned to further develop this method and to verify the method using radioactive samples. Procedures for analyzing radioactive samples of both pure NGS and blended solvent were developed and issued for the both methods.« less

Creating a false memory in the hippocampus.

PubMed

Ramirez, Steve; Liu, Xu; Lin, Pei-Ann; Suh, Junghyup; Pignatelli, Michele; Redondo, Roger L; Ryan, Tomás J; Tonegawa, Susumu

2013-07-26

Memories can be unreliable. We created a false memory in mice by optogenetically manipulating memory engram-bearing cells in the hippocampus. Dentate gyrus (DG) or CA1 neurons activated by exposure to a particular context were labeled with channelrhodopsin-2. These neurons were later optically reactivated during fear conditioning in a different context. The DG experimental group showed increased freezing in the original context, in which a foot shock was never delivered. The recall of this false memory was context-specific, activated similar downstream regions engaged during natural fear memory recall, and was also capable of driving an active fear response. Our data demonstrate that it is possible to generate an internally represented and behaviorally expressed fear memory via artificial means.

Characterization, scaling, and partial representation of diffuse and discrete input junctions to CA3 hippocampus.

PubMed

Ascarrunz, F G; Kisley, M A; Flach, K A; Hamilton, R W; MacGregor, R J

1995-07-01

This paper applies a general mathematical system for characterizing and scaling functional connectivity and information flow across the diffuse (EC) and discrete (DG) input junctions to the CA3 hippocampus. Both gross connectivity and coordinated multiunit informational firing patterns are quantitatively characterized in terms of 32 defining parameters interrelated by 17 equations, and then scaled down according to rules for uniformly proportional scaling and for partial representation. The diffuse EC-CA3 junction is shown to be uniformly scalable with realistic representation of both essential spatiotemporal cooperativity and coordinated firing patterns down to populations of a few hundred neurons. Scaling of the discrete DG-CA3 junction can be effected with a two-step process, which necessarily deviates from uniform proportionality but nonetheless produces a valuable and readily interpretable reduced model, also utilizing a few hundred neurons in the receiving population. Partial representation produces a reduced model of only a portion of the full network where each model neuron corresponds directly to a biological neuron. The mathematical analysis illustrated here shows that although omissions and distortions are inescapable in such an application, satisfactorily complete and accurate models the size of pattern modules are possible. Finally, the mathematical characterization of these junctions generates a theory which sees the DG as a definer of the fine structure of embedded traces in the hippocampus and entire coordinated patterns of sequences of 14-cell links in CA3 as triggered by the firing of sequences of individual neurons in DG.

Using Micro-Synchrophasor Data for Advanced Distribution Grid Planning and Operations Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stewart, Emma; Kiliccote, Sila; McParland, Charles

2014-07-01

This report reviews the potential for distribution-grid phase-angle data that will be available from new micro-synchrophasors (µPMUs) to be utilized in existing distribution-grid planning and operations analysis. This data could augment the current diagnostic capabilities of grid analysis software, used in both planning and operations for applications such as fault location, and provide data for more accurate modeling of the distribution system. µPMUs are new distribution-grid sensors that will advance measurement and diagnostic capabilities and provide improved visibility of the distribution grid, enabling analysis of the grid’s increasingly complex loads that include features such as large volumes of distributed generation.more » Large volumes of DG leads to concerns on continued reliable operation of the grid, due to changing power flow characteristics and active generation, with its own protection and control capabilities. Using µPMU data on change in voltage phase angle between two points in conjunction with new and existing distribution-grid planning and operational tools is expected to enable model validation, state estimation, fault location, and renewable resource/load characterization. Our findings include: data measurement is outstripping the processing capabilities of planning and operational tools; not every tool can visualize a voltage phase-angle measurement to the degree of accuracy measured by advanced sensors, and the degree of accuracy in measurement required for the distribution grid is not defined; solving methods cannot handle the high volumes of data generated by modern sensors, so new models and solving methods (such as graph trace analysis) are needed; standardization of sensor-data communications platforms in planning and applications tools would allow integration of different vendors’ sensors and advanced measurement devices. In addition, data from advanced sources such as µPMUs could be used to validate models to improve/ensure accuracy, providing information on normally estimated values such as underground conductor impedance, and characterization of complex loads. Although the input of high-fidelity data to existing tools will be challenging, µPMU data on phase angle (as well as other data from advanced sensors) will be useful for basic operational decisions that are based on a trend of changing data.« less

C-H Activation and Alkyne Annulation via Automatic or Intrinsic Directing Groups: Towards High Step Economy.

PubMed

Zheng, Liyao; Hua, Ruimao

2018-06-01

Direct transformation of carbon-hydrogen bond (C-H) has emerged to be a trend for construction of molecules from building blocks with no or less prefunctionalization, leading high atom and step economy. Directing group (DG) strategy is widely used to achieve higher reactivity and selectivity, but additional steps are usually needed for installation and/or cleavage of DGs, limiting step economy of the overall transformation. To meet this challenge, we proposed a concept of automatic DG (DG auto ), which is auto-installed and/or auto-cleavable. Multifunctional oxime and hydrazone DG auto were designed for C-H activation and alkyne annulation to furnish diverse nitrogen-containing heterocycles. Imidazole was employed as an intrinsic DG (DG in ) to synthesize ring-fused and π-extended functional molecules. The alkyne group in the substrates can also be served as DG in for ortho-C-H activation to afford carbocycles. In this account, we intend to give a review of our progress in this area and brief introduction of other related advances on C-H functionalization using DG auto or DG in strategies. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dystroglycan loss disrupts polarity and beta-casein induction inmammary epithelial cells by perturbing laminin anchoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weir, M. Lynn; Oppizzi, Maria Luisa; Henry, Michael D.

2006-02-17

Precise contact between epithelial cells and their underlying basement membrane is critical to the maintenance of tissue architecture and function. To understand the role that the laminin receptor dystroglycan (DG) plays in these processes, we assayed cell responses to laminin-111 following conditional ablation of DG expression in cultured mammary epithelial cells (MECs). Strikingly, DG loss disrupted laminin-111-induced polarity and {beta}-casein production, and abolished laminin assembly at the step of laminin binding to the cell surface. DG re-expression restored these deficiencies. Investigations of mechanism revealed that DG cytoplasmic sequences were not necessary for laminin assembly and signaling, and only when themore » entire mucin domain of extracellular DG was deleted did laminin assembly not occur. These results demonstrate that DG is essential as a laminin-111 co-receptor in MECs that functions by mediating laminin anchoring to the cell surface, a process that allows laminin polymerization, tissue polarity, and {beta}-casein induction. The observed loss of laminin-111 assembly and signaling in DG-/-MECs provides insights into the signaling changes occurring in breast carcinomas and other cancers, where DG's laminin-binding function is frequently defective.« less

Assessment of cathepsin D and L-like proteinases of poultry red mite, Dermanyssus gallinae (De Geer), as potential vaccine antigens.

PubMed

Bartley, Kathryn; Huntley, John F; Wright, Harry W; Nath, Mintu; Nisbet, Alasdair J

2012-05-01

Vaccination is a feasible strategy for controlling the haematophagous poultry red mite Dermanyssus gallinae. A cDNA library enriched for genes upregulated after feeding was created to identify potential vaccine antigens. From this library, a gene (Dg-CatD-1) encoding a 383 amino acid protein (Dg-CatD-1) with homology to cathepsin D lysosomal aspartyl proteinases was identified as a potential vaccine candidate. A second gene (Dg-CatL-1) encoding a 341 amino acid protein (Dg-CatL-1) with homology to cathepsin L cysteine proteinases was also selected for further study. IgY obtained from naturally infested hens failed to detect Dg-CatD-1 suggesting that it is a concealed antigen. Conversely, Dg-CatL-1 was detected by IgY derived from natural-infestation, indicating that infested hens are exposed to Dg-CatL-1. Mortality rates 120 h after mites had been fed anti-Dg-CatD-1 were significantly higher than those fed control IgY (PF<0·01). In a survival analysis, fitting a proportional hazards model to the time of death of mites, anti-Dg-CatD-1 and anti-Dg-CatL-1 IgY had 4·42 and 2·13 times higher risks of dying compared with controls (PF<0·05). Dg-CatD-1 and L-1 both have potential as vaccine antigens as part of a multi-component vaccine and have the potential to be improved as vaccine antigens using alternative expression systems.

78 FR 9792 - Airworthiness Directives; DG Flugzeugbau GmbH Gliders

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-12

... Airworthiness Directives; DG Flugzeugbau GmbH Gliders AGENCY: Federal Aviation Administration (FAA), Department... (AD) for DG Flugzeugbau GmbH Model DG-1000T gliders equipped with Solo Kleinmotoren Model 2350 C..., contact Solo Kleinmotoren GmbH, Postfach 60 01 52, D 71050 Sindelfingen, Germany; telephone: +49 07031-301...

Meeting DG's

ScienceCinema

None

2017-12-09

Le DG J.Adams commente les 3 thèmes de la réunion: 1.) le prochain DG du Cern (qui sera H.Schopper) 2.) le LEP 3.) les conclusions du comité des finances concernant salaires, allocations etc. Discussion entre le DG J.Adams, Mons.Ullmann, chef du personel et l'auditoire

Chill-inducing music enhances altruism in humans.

PubMed

Fukui, Hajime; Toyoshima, Kumiko

2014-01-01

Music is a universal feature of human cultures, and it has both fascinated and troubled many researchers. In this paper we show through the dictator game (DG) that an individual's listening to preferred "chill-inducing" music may promote altruistic behavior that extends beyond the bounds of kin selection or reciprocal altruism. Participants were 22 undergraduate and postgraduate students who were divided into two groups, the in-group and the out-group, and they acted as dictators. The dictators listened to their own preferred "chill-inducing" music, to music they disliked, or to silence, and then played the DG. In this hypothetical experiment, the dictators were given real money (which they did not keep) and were asked to distribute it to the recipients, who were presented as stylized images of men and women displayed on a computer screen. The dictators played the DG both before and after listening to the music. Both male and female dictators gave more money after listening to their preferred music and less after listening to the music they disliked, whereas silence had no effect on the allocated amounts. The group to which the recipient belonged did not influence these trends. The results suggest that listening to preferred "chill-inducing" music promotes altruistic behavior.

Increase in cellular triacylglycerol content and emergence of large ER-associated lipid droplets in the absence of CDP-DG synthase function.

PubMed

He, Yue; Yam, Candice; Pomraning, Kyle; Chin, Jacqueline S R; Yew, Joanne Y; Freitag, Michael; Oliferenko, Snezhana

2014-12-15

Excess fatty acids and sterols are stored as triacylglycerols and sterol esters in specialized cellular organelles, called lipid droplets. Understanding what determines the cellular amount of neutral lipids and their packaging into lipid droplets is of fundamental and applied interest. Using two species of fission yeast, we show that cycling cells deficient in the function of the ER-resident CDP-DG synthase Cds1 exhibit markedly increased triacylglycerol content and assemble large lipid droplets closely associated with the ER membranes. We demonstrate that these unusual structures recruit the triacylglycerol synthesis machinery and grow by expansion rather than by fusion. Our results suggest that interfering with the CDP-DG route of phosphatidic acid utilization rewires cellular metabolism to adopt a triacylglycerol-rich lifestyle reliant on the Kennedy pathway. © 2014 He, Yam, et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Maui Smart Grid Demonstration Project Managing Distribution System Resources for Improved Service Quality and Reliability, Transmission Congestion Relief, and Grid Support Functions

DOE Office of Scientific and Technical Information (OSTI.GOV)

none,

2014-09-30

The Maui Smart Grid Project (MSGP) is under the leadership of the Hawaii Natural Energy Institute (HNEI) of the University of Hawaii at Manoa. The project team includes Maui Electric Company, Ltd. (MECO), Hawaiian Electric Company, Inc. (HECO), Sentech (a division of SRA International, Inc.), Silver Spring Networks (SSN), Alstom Grid, Maui Economic Development Board (MEDB), University of Hawaii-Maui College (UHMC), and the County of Maui. MSGP was supported by the U.S. Department of Energy (DOE) under Cooperative Agreement Number DE-FC26-08NT02871, with approximately 50% co-funding supplied by MECO. The project was designed to develop and demonstrate an integrated monitoring, communications,more » database, applications, and decision support solution that aggregates renewable energy (RE), other distributed generation (DG), energy storage, and demand response technologies in a distribution system to achieve both distribution and transmission-level benefits. The application of these new technologies and procedures will increase MECO’s visibility into system conditions, with the expected benefits of enabling more renewable energy resources to be integrated into the grid, improving service quality, increasing overall reliability of the power system, and ultimately reducing costs to both MECO and its customers.« less

Adult Neurogenesis in the Mammalian Hippocampus: Why the Dentate Gyrus?

ERIC Educational Resources Information Center

Drew, Liam J.; Fusi, Stefano; Hen, René

2013-01-01

In the adult mammalian brain, newly generated neurons are continuously incorporated into two networks: interneurons born in the subventricular zone migrate to the olfactory bulb, whereas the dentate gyrus (DG) of the hippocampus integrates locally born principal neurons. That the rest of the mammalian brain loses significant neurogenic capacity…

Running increases neurogenesis without retinoic acid receptor activation in the adult mouse dentate gyrus.

PubMed

Aberg, Elin; Perlmann, Thomas; Olson, Lars; Brené, Stefan

2008-01-01

Both vitamin A deficiency and high doses of retinoids can result in learning and memory impairments, depression as well as decreases in cell proliferation, neurogenesis and cell survival. Physical activity enhances hippocampal neurogenesis and can also exert an antidepressant effect. Here we elucidate a putative link between running, retinoid signaling, and neurogenesis in hippocampus. Adult transgenic reporter mice designed to detect ligand-activated retinoic acid receptors (RAR) or retinoid X receptors (RXR) were used to localize the distribution of activated RAR or RXR at the single-cell level in the brain. Two months of voluntary wheel-running induced an increase in hippocampal neurogenesis as indicated by an almost two-fold increase in doublecortin-immunoreactive cells. Running activity was correlated with neurogenesis. Under basal conditions a distinct pattern of RAR-activated cells was detected in the granule cell layer of the dentate gyrus (DG), thalamus, and cerebral cortex layers 3-4 and to a lesser extent in hippocampal pyramidal cell layers CA1-CA3. Running did not change the number of RAR-activated cells in the DG. There was no correlation between running and RAR activation or between RAR activation and neurogenesis in the DG of hippocampus. Only a few scattered activated retinoid X receptors were found in the DG under basal conditions and after wheel-running, but RXR was detected in other areas such as in the hilus region of hippocampus and in layer VI of cortex cerebri. RAR agonists affect mood in humans and reduce neurogenesis, learning and memory in animal models. In our study, long-term running increased neurogenesis but did not alter RAR ligand activation in the DG in individually housed mice. Thus, our data suggest that the effects of exercise on neurogenesis and other plasticity changes in the hippocampal formation are mediated by mechanisms that do not involve retinoid receptor activation. (c) 2008 Wiley-Liss, Inc.

Mapping of Ozone on Mars at Infrared Wavelengths Using Crires at VLT

NASA Astrophysics Data System (ADS)

Radeva, Y. L.; Mumma, M. J.; Villanueva, G.; Novak, R.; Hartogh, P.; Encrenaz, T.; Kaufl, H.; Smette, A.

2010-12-01

We present spatially resolved maps of ozone and water on Mars, acquired on 21 August 2009 using the ultra-high resolution infrared spectrometer CRIRES at ESO’s VLT (Paranal, Chile). On Mars, the season was mid-summer in the South (Ls = 325) and the latitudinal resolution was 10 degrees FWHM at disk center. Ozone is produced by recombination of photochemically produced O and O2. It is destroyed by UV photolysis (with O2 (a1Dg) as a principal product) but also by reaction with odd hydrogen species (especially, H - a product of H2O vapor photolysis). Thus, simultaneous measurements of water and ozone can test this relationship. We quantified ozone using spectral lines (near 1.27 mm) of O2 (a1Dg). The emission from O2 (a1Dg) serves as a tracer for O3 above 20 km, since at lower altitudes collisions with CO2 quench the excited O2 (a1Dg) molecules. We confirmed the vertical location of the O2 (a1Dg) emission by extracting rotational temperatures from line-by-line ratios, and comparing them with standard vertical temperature profiles for this season and location(s). On the same night, we also obtained 2-D (lat-long) maps of Martian water from multiple H2O lines detected in the 3.3 mm region. We compare our retrieved distributions for ozone (latitude and altitude) with predictions of Lefevre et al. [I] based on their comprehensive 3-D circulation and photochemical model for the Martian atmosphere. Acknowledgements: This work was funded by NASA’s R&A Programs in Astrobiology (344-53-51), Planetary Astronomy (344-32-51-96), and Planetary Atmospheres (NNX09AB65G). We gratefully acknowledge the Director and staff of the European Southern Observatory, for supporting these observations. References: [I] Lefevre et al. (2004), J. of Geophys. Res. 109, E07004

Visualizing Metal Content and Intracellular Distribution in Primary Hippocampal Neurons with Synchrotron X-Ray Fluorescence

DOE PAGES

Colvin, Robert A.; Jin, Qiaoling; Lai, Barry; ...

2016-07-19

Increasing evidence suggests that metal dyshomeostasis plays an important role in human neurodegenerative diseases. Although distinctive metal distributions are described for mature hippocampus and cortex, much less is known about metal levels and intracellular distribution in individual hippocampal neuronal somata. To solve this problem, we conducted quantitative metal analyses utilizing synchrotron radiation X-Ray fluorescence on frozen hydrated primary cultured neurons derived from rat embryonic cortex (CTX) and two regions of the hippocampus: dentate gyrus (DG) and CA1. Also, comparing average metal contents showed that the most abundant metals were calcium, iron, and zinc, whereas metals such as copper and manganesemore » were less than 10% of zinc. Average metal contents were generally similar when compared across neurons cultured from CTX, DG, and CA1, except for manganese that was larger in CA1. However, each metal showed a characteristic spatial distribution in individual neuronal somata. Zinc was uniformly distributed throughout the cytosol, with no evidence for the existence of previously identified zinc-enriched organelles, zincosomes. Calcium showed a peri-nuclear distribution consistent with accumulation in endoplasmic reticulum and/or mitochondria. Iron showed 2-3 distinct highly concentrated puncta only in peri-nuclear locations. Notwithstanding the small sample size, these analyses demonstrate that primary cultured neurons show characteristic metal signatures. The iron puncta probably represent iron-accumulating organelles, siderosomes. Thus, the metal distributions observed in mature brain structures are likely the result of both intrinsic neuronal factors that control cellular metal content and extrinsic factors related to the synaptic organization, function, and contacts formed and maintained in each region.« less

Visualizing Metal Content and Intracellular Distribution in Primary Hippocampal Neurons with Synchrotron X-Ray Fluorescence

PubMed Central

2016-01-01

Increasing evidence suggests that metal dyshomeostasis plays an important role in human neurodegenerative diseases. Although distinctive metal distributions are described for mature hippocampus and cortex, much less is known about metal levels and intracellular distribution in individual hippocampal neuronal somata. To solve this problem, we conducted quantitative metal analyses utilizing synchrotron radiation X-Ray fluorescence on frozen hydrated primary cultured neurons derived from rat embryonic cortex (CTX) and two regions of the hippocampus: dentate gyrus (DG) and CA1. Comparing average metal contents showed that the most abundant metals were calcium, iron, and zinc, whereas metals such as copper and manganese were less than 10% of zinc. Average metal contents were generally similar when compared across neurons cultured from CTX, DG, and CA1, except for manganese that was larger in CA1. However, each metal showed a characteristic spatial distribution in individual neuronal somata. Zinc was uniformly distributed throughout the cytosol, with no evidence for the existence of previously identified zinc-enriched organelles, zincosomes. Calcium showed a peri-nuclear distribution consistent with accumulation in endoplasmic reticulum and/or mitochondria. Iron showed 2–3 distinct highly concentrated puncta only in peri-nuclear locations. Notwithstanding the small sample size, these analyses demonstrate that primary cultured neurons show characteristic metal signatures. The iron puncta probably represent iron-accumulating organelles, siderosomes. Thus, the metal distributions observed in mature brain structures are likely the result of both intrinsic neuronal factors that control cellular metal content and extrinsic factors related to the synaptic organization, function, and contacts formed and maintained in each region. PMID:27434052

75 FR 45677 - Draft Regulatory Guide, DG-1216,”Plant-Specific Applicability of Transition Break Size Specified...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-03

... NUCLEAR REGULATORY COMMISSION [NRC-2010-0229] Draft Regulatory Guide, DG-1216,''Plant-Specific... Commission (NRC) is extending the public comment period for DG-1216 from August 25, 2010 to November 8, 2010... [email protected] . The Draft Regulatory Guide, DG-1216, ``Plant- Specific Applicability of...

Dystroglycan and Protein O-Mannosyltransferases 1 and 2 Are Required to Maintain Integrity of Drosophila Larval Muscles

PubMed Central

Seabrooke, Sara; Stewart, Bryan A.

2007-01-01

In vertebrates, mutations in Protein O-mannosyltransferase1 (POMT1) or POMT2 are associated with muscular dystrophy due to a requirement for O-linked mannose glycans on the Dystroglycan (Dg) protein. In this study we examine larval body wall muscles of Drosophila mutant for Dg, or RNA interference knockdown for Dg and find defects in muscle attachment, altered muscle contraction, and a change in muscle membrane resistance. To determine if POMTs are required for Dg function in Drosophila, we examine larvae mutant for genes encoding POMT1 or POMT2. Larvae mutant for either POMT, or doubly mutant for both, show muscle attachment and muscle contraction phenotypes identical to those associated with reduced Dg function, consistent with a requirement for O-linked mannose on Drosophila Dg. Together these data establish a central role for Dg in maintaining integrity in Drosophila larval muscles and demonstrate the importance of glycosylation to Dg function in Drosophila. This study opens the possibility of using Drosophila to investigate muscular dystrophy. PMID:17881734

A Reconstructed Discontinuous Galerkin Method for the Compressible Euler Equations on Arbitrary Grids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong Luo; Luquing Luo; Robert Nourgaliev

2009-06-01

A reconstruction-based discontinuous Galerkin (DG) method is presented for the solution of the compressible Euler equations on arbitrary grids. By taking advantage of handily available and yet invaluable information, namely the derivatives, in the context of the discontinuous Galerkin methods, a solution polynomial of one degree higher is reconstructed using a least-squares method. The stencils used in the reconstruction involve only the van Neumann neighborhood (face-neighboring cells) and are compact and consistent with the underlying DG method. The resulting DG method can be regarded as an improvement of a recovery-based DG method in the sense that it shares the samemore » nice features as the recovery-based DG method, such as high accuracy and efficiency, and yet overcomes some of its shortcomings such as a lack of flexibility, compactness, and robustness. The developed DG method is used to compute a variety of flow problems on arbitrary meshes to demonstrate the accuracy and efficiency of the method. The numerical results indicate that this reconstructed DG method is able to obtain a third-order accurate solution at a slightly higher cost than its second-order DG method and provide an increase in performance over the third order DG method in terms of computing time and storage requirement.« less

Subgingival Microbiota in White Patients With Desquamative Gingivitis: A Cross-Sectional Study.

PubMed

Arduino, Paolo G; Romano, Federica; Sasia, Danilo; Broccoletti, Roberto; Ricceri, Fulvio; Barbui, Anna Maria; Brossa, Silvia; Cipriani, Raffaella; Cricenti, Luca; Cabras, Marco; Aimetti, Mario

2017-07-01

Presence of epithelial desquamation, erythema, and erosions on gingival tissue is usually described in the literature as desquamative gingivitis (DG). A wide range of autoimmune/dermatologic disorders can manifest as DG, although the two more common are oral lichen planus and mucous membrane pemphigoid. The aim of this study is to investigate prevalence of 11 periodontopathogenic microorganisms in patients with DG and to compare it with the microbiologic status of individuals affected by plaque-induced gingivitis (pGI). Cross-sectional clinical and microbiologic data were obtained from 66 patients (33 in each group). Subgingival plaque samples were analyzed using semiquantitative polymerase chain reaction analysis. Statistically significant difference, but with little clinical significance, was observed in gingival conditions between the two groups, probably due to the worse home control hygiene of patients with DG. Prevalence and levels of Aggregatibacter actinomycetemcomitans, Eikenella corrodens, and Fusobacterium nucleatum/periodonticum were statistically higher in samples from patients with DG than in those with pGI. In multivariate regression models, subgingival colonization of A. actinomycetemcomitans and F. nucleatum/periodonticum was not statistically associated with DG, whereas, high levels of E. corrodens were associated with 13-fold increased odds for DG. Microbiologic differences were found in subgingival plaque for patients with DG and pGI. This may suggest possible association between periodontal pathogens and DG.

Structural characterization by NMR of the natively unfolded extracellular domain of beta-dystroglycan: toward the identification of the binding epitope for alpha-dystroglycan.

PubMed

Bozzi, Manuela; Bianchi, Marzia; Sciandra, Francesca; Paci, Maurizio; Giardina, Bruno; Brancaccio, Andrea; Cicero, Daniel O

2003-11-25

Dystroglycan (DG) is an adhesion molecule playing a crucial role for tissue stability during both early embriogenesis and adulthood and is composed by two tightly interacting subunits: alpha-DG, membrane-associated and highly glycosylated, and the transmembrane beta-DG. Recently, by solid-phase binding assays and NMR experiments, we have shown that the C-terminal domain of alpha-DG interacts with a recombinant extracellular fragment of beta-DG (positions 654-750) independently from glycosylation and that the linear binding epitope is located between residues 550 and 565 of alpha-DG. In order to elucidate which moieties of beta-DG are specifically involved in the complex with alpha-DG, the ectodomain has been recombinantly expressed and purified in a labeled ((13)C,(15)N) form and studied by multidimensional NMR. Although it represents a natively unfolded protein domain, we obtained an almost complete backbone assignment. Chemical shift index, (1)H-(15)N heteronuclear single-quantum coherence and nuclear Overhauser effect (HSQC-NOESY) spectra and (3)J(HN,H)(alpha) coupling constant values confirm that this protein is highly disordered, but (1)H-(15)N steady-state NOE experiments indicate that the protein presents two regions of different mobility. The first one, between residues 659 and 722, is characterized by a limited degree of mobility, whereas the C-terminal portion, containing about 30 amino acids, is highly flexible. The binding of beta-DG(654-750) to the C-terminal region of the alpha subunit, alpha-DG(485-620), has been investigated, showing that the region of beta-DG(654-750) between residues 691 and 719 is involved in the interaction.

Dentate Gyrus Contributes to Retrieval as well as Encoding: Evidence from Context Fear Conditioning, Recall, and Extinction

PubMed Central

Krasne, Franklin B.

2017-01-01

Dentate gyrus (DG) is widely thought to provide a teaching signal that enables hippocampal encoding of memories, but its role during retrieval is poorly understood. Some data and models suggest that DG plays no role in retrieval; others encourage the opposite conclusion. To resolve this controversy, we evaluated the effects of optogenetic inhibition of dorsal DG during context fear conditioning, recall, generalization, and extinction in male mice. We found that (1) inhibition during training impaired context fear acquisition; (2) inhibition during recall did not impair fear expression in the training context, unless mice had to distinguish between similar feared and neutral contexts; (3) inhibition increased generalization of fear to an unfamiliar context that was similar to a feared one and impaired fear expression in the conditioned context when it was similar to a neutral one; and (4) inhibition impaired fear extinction. These effects, as well as several seemingly contradictory published findings, could be reproduced by BACON (Bayesian Context Fear Algorithm), a physiologically realistic hippocampal model positing that acquisition and retrieval both involve coordinated activity in DG and CA3. Our findings thus suggest that DG contributes to retrieval and extinction, as well as to the initial establishment of context fear. SIGNIFICANCE STATEMENT Despite abundant evidence that the hippocampal dentate gyrus (DG) plays a critical role in memory, it remains unclear whether the role of DG relates to memory acquisition or retrieval. Using contextual fear conditioning and optogenetic inhibition, we show that DG contributes to both of these processes. Using computational simulations, we identify specific mechanisms through which the suppression of DG affects memory performance. Finally, we show that DG contributes to fear extinction learning, a process in which learned fear is attenuated through exposures to a fearful context in the absence of threat. Our data resolve a long-standing question about the role of DG in memory and provide insight into how disorders affecting DG, including aging, stress, and depression, influence cognitive processes. PMID:28546308

Nuclear Import of β-Dystroglycan Is Facilitated by Ezrin-Mediated Cytoskeleton Reorganization

PubMed Central

Vásquez-Limeta, Alejandra; Wagstaff, Kylie M.; Ortega, Arturo; Crouch, Dorothy H.; Jans, David A.; Cisneros, Bulmaro

2014-01-01

The β-dystroglycan (β-DG) protein has the ability to target to multiple sites in eukaryotic cells, being a member of diverse protein assemblies including the transmembranal dystrophin-associated complex, and a nuclear envelope-localised complex that contains emerin and lamins A/C and B1. We noted that the importin α2/β1-recognised nuclear localization signal (NLS) of β-DG is also a binding site for the cytoskeletal-interacting protein ezrin, and set out to determine whether ezrin binding might modulate β-DG nuclear translocation for the first time. Unexpectedly, we found that ezrin enhances rather than inhibits β-DG nuclear translocation in C2C12 myoblasts. Both overexpression of a phosphomimetic activated ezrin variant (Ez-T567D) and activation of endogenous ezrin through stimulation of the Rho pathway resulted in both formation of actin-rich surface protrusions and significantly increased nuclear translocation of β-DG as shown by quantitative microscopy and subcellular fractionation/Western analysis. In contrast, overexpression of a nonphosphorylatable inactive ezrin variant (Ez-T567A) or inhibition of Rho signaling, decreased nuclear translocation of β-DG concomitant with a lack of cell surface protrusions. Further, a role for the actin cytoskeleton in ezrin enhancement of β-DG nuclear translocation was implicated by the observation that an ezrin variant lacking its actin-binding domain failed to enhance nuclear translocation of β-DG, while disruption of the actin cytoskeleton led to a reduction in β-DG nuclear localization. Finally, we show that ezrin-mediated cytoskeletal reorganization enhances nuclear translocation of the cytoplasmic but not the transmembranal fraction of β-DG. This is the first study showing that cytoskeleton reorganization can modulate nuclear translocation of β-DG, with the implication that β-DG can respond to cytoskeleton-driven changes in cell morphology by translocating from the cytoplasm to the nucleus to orchestrate nuclear processes in response to the functional requirements of the cell. PMID:24599031

2-Deoxyglucose induces the expression of thioredoxin interacting protein (TXNIP) by increasing O-GlcNAcylation – Implications for targeting the Warburg effect in cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong, Shin Yee; Hagen, Thilo, E-mail: bchth@nus.edu.sg

2015-10-02

The high proliferation rate of cancer cells and the microenvironment in the tumor tissue require the reprogramming of tumor cell metabolism. The major mechanism of metabolic reprogramming in cancer cells is the Warburg effect, defined as the preferential utilization of glucose via glycolysis even in the presence of oxygen. Targeting the Warburg effect is considered as a promising therapeutic strategy in cancer therapy. In this regard, the glycolytic inhibitor 2-deoxyglucose (2DG) has been evaluated clinically. 2DG exerts its effect by directly inhibiting glycolysis at the level of hexokinase and phosphoglucoisomerase. In addition, 2DG is also known to induce the expressionmore » of thioredoxin interacting protein (TXNIP), a tumor suppressor protein and an important negative regulator of cellular glucose uptake. Hence, characterization of the mechanism through which 2DG regulates TXNIP expression may reveal novel approaches to target the Warburg effect in cancer cells. Therefore, in this study we sought to test various hypotheses for the mechanistic basis of the 2DG dependent TXNIP regulation. We have shown that 2DG induced TXNIP expression is independent of carbohydrate response element mediated transcription. Furthermore, the induction of TXNIP is neither dependent on the ability of 2DG to deplete cellular ATP nor to cause endoplasmic reticulum stress. We found that the 2DG induced TXNIP expression is at least in part dependent on the inhibition of the O-GlcNAcase enzyme and the accumulation of O-GlcNAc modified proteins. These results have implications for the identification of therapeutic targets to increase TXNIP expression in cancer. - Highlights: • 2DG increases TXNIP expression at the mRNA and protein level. • The effect of 2DG on TXNIP is independent of ChoRE mediated transcription. • 2DG induces TXNIP independent of ER stress induction and ATP depletion. • 2DG inhibits OGA and leads to accumulation of O-GlcNAcylated proteins. • The upregulation of TXNIP by 2DG is partially due to an increase in O-GlcNAcylation.« less

A Monte Carlo model for mean glandular dose evaluation in spot compression mammography.

PubMed

Sarno, Antonio; Dance, David R; van Engen, Ruben E; Young, Kenneth C; Russo, Paolo; Di Lillo, Francesca; Mettivier, Giovanni; Bliznakova, Kristina; Fei, Baowei; Sechopoulos, Ioannis

2017-07-01

To characterize the dependence of normalized glandular dose (DgN) on various breast model and image acquisition parameters during spot compression mammography and other partial breast irradiation conditions, and evaluate alternative previously proposed dose-related metrics for this breast imaging modality. Using Monte Carlo simulations with both simple homogeneous breast models and patient-specific breasts, three different dose-related metrics for spot compression mammography were compared: the standard DgN, the normalized glandular dose to only the directly irradiated portion of the breast (DgNv), and the DgN obtained by the product of the DgN for full field irradiation and the ratio of the mid-height area of the irradiated breast to the entire breast area (DgN M ). How these metrics vary with field-of-view size, spot area thickness, x-ray energy, spot area and position, breast shape and size, and system geometry was characterized for the simple breast model and a comparison of the simple model results to those with patient-specific breasts was also performed. The DgN in spot compression mammography can vary considerably with breast area. However, the difference in breast thickness between the spot compressed area and the uncompressed area does not introduce a variation in DgN. As long as the spot compressed area is completely within the breast area and only the compressed breast portion is directly irradiated, its position and size does not introduce a variation in DgN for the homogeneous breast model. As expected, DgN is lower than DgNv for all partial breast irradiation areas, especially when considering spot compression areas within the clinically used range. DgN M underestimates DgN by 6.7% for a W/Rh spectrum at 28 kVp and for a 9 × 9 cm 2 compression paddle. As part of the development of a new breast dosimetry model, a task undertaken by the American Association of Physicists in Medicine and the European Federation of Organizations of Medical Physics, these results provide insight on how DgN and two alternative dose metrics behave with various image acquisition and model parameters. © 2017 American Association of Physicists in Medicine.

Sparse and Specific Coding during Information Transmission between Co-cultured Dentate Gyrus and CA3 Hippocampal Networks

PubMed Central

Poli, Daniele; Thiagarajan, Srikanth; DeMarse, Thomas B.; Wheeler, Bruce C.; Brewer, Gregory J.

2017-01-01

To better understand encoding and decoding of stimulus information in two specific hippocampal sub-regions, we isolated and co-cultured rat primary dentate gyrus (DG) and CA3 neurons within a two-chamber device with axonal connectivity via micro-tunnels. We tested the hypothesis that, in these engineered networks, decoding performance of stimulus site information would be more accurate when stimuli and information flow occur in anatomically correct feed-forward DG to CA3 vs. CA3 back to DG. In particular, we characterized the neural code of these sub-regions by measuring sparseness and uniqueness of the responses evoked by specific paired-pulse stimuli. We used the evoked responses in CA3 to decode the stimulation sites in DG (and vice-versa) by means of learning algorithms for classification (support vector machine, SVM). The device was placed over an 8 × 8 grid of extracellular electrodes (micro-electrode array, MEA) in order to provide a platform for monitoring development, self-organization, and improved access to stimulation and recording at multiple sites. The micro-tunnels were designed with dimensions 3 × 10 × 400 μm allowing axonal growth but not migration of cell bodies and long enough to exclude traversal by dendrites. Paired-pulse stimulation (inter-pulse interval 50 ms) was applied at 22 different sites and repeated 25 times in each chamber for each sub-region to evoke time-locked activity. DG-DG and CA3-CA3 networks were used as controls. Stimulation in DG drove signals through the axons in the tunnels to activate a relatively small set of specific electrodes in CA3 (sparse code). CA3-CA3 and DG-DG controls were less sparse in coding than CA3 in DG-CA3 networks. Using all target electrodes with the three highest spike rates (14%), the evoked responses in CA3 specified each stimulation site in DG with optimum uniqueness of 64%. Finally, by SVM learning, these evoked responses in CA3 correctly decoded the stimulation sites in DG for 43% of the trials, significantly higher than the reverse, i.e., how well-recording in DG could predict the stimulation site in CA3. In conclusion, our co-cultured model for the in vivo DG-CA3 hippocampal network showed sparse and specific responses in CA3, selectively evoked by each stimulation site in DG. PMID:28321182

A Three-Parameter Generalisation of the Beta-Binomial Distribution with Applications

DTIC Science & Technology

1987-07-01

York. Rust, R.T. and Klompmaker, J.E. (1981). Improving the estimation procedure for the beta binomial t.v. exposure model. Journal of Marketing ... Research . 18, 442-448. Sabavala, D.J. and Morrison, D.G. (1977). Television show loyalty: a beta- binomial model using recall data. Journal of Advertiuing

Extension of the Peters–Belson method to estimate health disparities among multiple groups using logistic regression with survey data

PubMed Central

Li, Y.; Graubard, B. I.; Huang, P.; Gastwirth, J. L.

2015-01-01

Determining the extent of a disparity, if any, between groups of people, for example, race or gender, is of interest in many fields, including public health for medical treatment and prevention of disease. An observed difference in the mean outcome between an advantaged group (AG) and disadvantaged group (DG) can be due to differences in the distribution of relevant covariates. The Peters–Belson (PB) method fits a regression model with covariates to the AG to predict, for each DG member, their outcome measure as if they had been from the AG. The difference between the mean predicted and the mean observed outcomes of DG members is the (unexplained) disparity of interest. We focus on applying the PB method to estimate the disparity based on binary/multinomial/proportional odds logistic regression models using data collected from complex surveys with more than one DG. Estimators of the unexplained disparity, an analytic variance–covariance estimator that is based on the Taylor linearization variance–covariance estimation method, as well as a Wald test for testing a joint null hypothesis of zero for unexplained disparities between two or more minority groups and a majority group, are provided. Simulation studies with data selected from simple random sampling and cluster sampling, as well as the analyses of disparity in body mass index in the National Health and Nutrition Examination Survey 1999–2004, are conducted. Empirical results indicate that the Taylor linearization variance–covariance estimation is accurate and that the proposed Wald test maintains the nominal level. PMID:25382235

Pleistocene refugia and genetic diversity patterns in West Africa: Insights from the liana Chasmanthera dependens (Menispermaceae)

PubMed Central

Schmidt, Marco; Muellner-Riehl, Alexandra Nora; Ogundipe, Oluwatoyin Temitayo; Paule, Juraj

2017-01-01

Processes shaping the African Guineo-Congolian rain forest, especially in the West African part, are not well understood. Recent molecular studies, based mainly on forest tree species, confirmed the previously proposed division of the western African Guineo-Congolian rain forest into Upper Guinea (UG) and Lower Guinea (LG) separated by the Dahomey Gap (DG). Here we studied nine populations in the area of the DG and the borders of LG and UG of the widespread liana species, Chasmanthera dependens (Menispermaceae) by amplified fragment length polymorphism (AFLP), a chloroplast DNA sequence marker, and modelled the distribution based on current as well as paleoclimatic data (Holocene Climate Optimum, ca. 6 kyr BP and Last Glacial Maximum, ca. 22 kyr BP). Current population genetic structure and geographical pattern of cpDNA was related to present as well as historical modelled distributions. Results from this study show that past historical factors played an important role in shaping the distribution of C. dependens across West Africa. The Cameroon Volcanic Line seems to represent a barrier for gene flow in the present as well as in the past. Distribution modelling proposed refugia in the Dahomey Gap, supported also by higher genetic diversity. This is in contrast with the phylogeographic patterns observed in several rainforest tree species and could be explained by either diverging or more relaxed ecological requirements of this liana species. PMID:28301470

A double chain reversal loop and two diagonal loops define the architecture of a unimolecular DNA quadruplex containing a pair of stacked G(syn)-G(syn)-G(anti)-G(anti) tetrads flanked by a G-(T-T) Triad and a T-T-T triple.

PubMed

Kuryavyi, V; Majumdar, A; Shallop, A; Chernichenko, N; Skripkin, E; Jones, R; Patel, D J

2001-06-29

The architecture of G-G-G-G tetrad-aligned DNA quadruplexes in monovalent cation solution is dependent on the directionality of the four strands, which in turn are defined by loop connectivities and the guanine syn/anti distribution along individual strands and within individual G-G-G-G tetrads. The smallest unimolecular G-quadruplex belongs to the d(G2NnG2NnG2NnG2) family, which has the potential to form two stacked G-tetrads linked by Nn loop connectivities. Previous studies have focused on the thrombin-binding DNA aptamer d(G2T2G2TGTG2T2G2), where Nn was T2 for the first and third connecting loops and TGT for the middle connecting loop. This DNA aptamer in K(+) cation solution forms a unimolecular G-quadruplex stabilized by two stacked G(syn)-G(anti)-G(syn)-G(anti) tetrads, adjacent strands which are antiparallel to each other and edge-wise connecting T2, TGT and T2 loops. We now report on the NMR-based solution structure of the d(G2T4G2CAG2GT4G2T) sequence, which differs from the thrombin-binding DNA aptamer sequence in having longer first (T4) and third (GT4) loops and a shorter (CA) middle loop. This d(G2T4G2CAG2GT4G2T) sequence in Na(+) cation solution forms a unimolecular G-quadruplex stabilized by two stacked G(syn)-G(syn)-G(anti)-G(anti) tetrads, adjacent strands which have one parallel and one antiparallel neighbors and distinct non-edge-wise loop connectivities. Specifically, the longer first (T4) and third (GT4) loops are of the diagonal type while the shorter middle loop is of the double chain reversal type. In addition, the pair of stacked G-G-G-G tetrads are flanked on one side by a G-(T-T) triad and on the other side by a T-T-T triple. The distinct differences in strand directionalities, loop connectivities and syn/anti distribution within G-G-G-G tetrads between the thrombin-binding DNA aptamer d(G2T2G2TGTG2T2G2) quadruplex reported previously, and the d(G2T4G2CAG2GT4G2T) quadruplex reported here, reinforces the polymorphic nature of higher-order DNA architectures. Further, these two small unimolecular G-quadruplexes, which are distinct from each other and from parallel-stranded G-quadruplexes, provide novel targets for ligand recognition. Our results demonstrate that the double chain reversal loop connectivity identified previously by our laboratory within the Tetrahymena telomere d(T2G4)4 quadruplex, is a robust folding topology, since it has now also been observed within the d(G2T4G2CAG2GT4G2T) quadruplex. The identification of a G-(T-T) triad and a T-T-T triple, expands on the available recognition alignments for base triads and triples. Copyright 2001 Academic Press.

Effects of drain bias on the statistical variation of double-gate tunnel field-effect transistors

NASA Astrophysics Data System (ADS)

Choi, Woo Young

2017-04-01

The effects of drain bias on the statistical variation of double-gate (DG) tunnel field-effect transistors (TFETs) are discussed in comparison with DG metal-oxide-semiconductor FETs (MOSFETs). Statistical variation corresponds to the variation of threshold voltage (V th), subthreshold swing (SS), and drain-induced barrier thinning (DIBT). The unique statistical variation characteristics of DG TFETs and DG MOSFETs with the variation of drain bias are analyzed by using full three-dimensional technology computer-aided design (TCAD) simulation in terms of the three dominant variation sources: line-edge roughness (LER), random dopant fluctuation (RDF) and workfunction variation (WFV). It is observed than DG TFETs suffer from less severe statistical variation as drain voltage increases unlike DG MOSFETs.

Novel encoding and updating of positional, or directional, spatial cues are processed by distinct hippocampal subfields: Evidence for parallel information processing and the "what" stream.

PubMed

Hoang, Thu-Huong; Aliane, Verena; Manahan-Vaughan, Denise

2018-05-01

The specific roles of hippocampal subfields in spatial information processing and encoding are, as yet, unclear. The parallel map theory postulates that whereas the CA1 processes discrete environmental features (positional cues used to generate a "sketch map"), the dentate gyrus (DG) processes large navigation-relevant landmarks (directional cues used to generate a "bearing map"). Additionally, the two-streams hypothesis suggests that hippocampal subfields engage in differentiated processing of information from the "where" and the "what" streams. We investigated these hypotheses by analyzing the effect of exploration of discrete "positional" features and large "directional" spatial landmarks on hippocampal neuronal activity in rats. As an indicator of neuronal activity we measured the mRNA induction of the immediate early genes (IEGs), Arc and Homer1a. We observed an increase of this IEG mRNA in CA1 neurons of the distal neuronal compartment and in proximal CA3, after novel spatial exploration of discrete positional cues, whereas novel exploration of directional cues led to increases in IEG mRNA in the lower blade of the DG and in proximal CA3. Strikingly, the CA1 did not respond to directional cues and the DG did not respond to positional cues. Our data provide evidence for both the parallel map theory and the two-streams hypothesis and suggest a precise compartmentalization of the encoding and processing of "what" and "where" information occurs within the hippocampal subfields. © 2018 The Authors. Hippocampus Published by Wiley Periodicals, Inc.

Optimal Dispatch of Unreliable Electric Grid-Connected Diesel Generator-Battery Power Systems

NASA Astrophysics Data System (ADS)

Xu, D.; Kang, L.

2015-06-01

Diesel generator (DG)-battery power systems are often adopted by telecom operators, especially in semi-urban and rural areas of developing countries. Unreliable electric grids (UEG), which have frequent and lengthy outages, are peculiar to these regions. DG-UEG-battery power system is an important kind of hybrid power system. System dispatch is one of the key factors to hybrid power system integration. In this paper, the system dispatch of a DG-UEG-lead acid battery power system is studied with the UEG of relatively ample electricity in Central African Republic (CAR) and UEG of poor electricity in Congo Republic (CR). The mathematical models of the power system and the UEG are studied for completing the system operation simulation program. The net present cost (NPC) of the power system is the main evaluation index. The state of charge (SOC) set points and battery bank charging current are the optimization variables. For the UEG in CAR, the optimal dispatch solution is SOC start and stop points 0.4 and 0.5 that belong to the Micro-Cycling strategy and charging current 0.1 C. For the UEG in CR, the optimal dispatch solution is of 0.1 and 0.8 that belongs to the Cycle-Charging strategy and 0.1 C. Charging current 0.1 C is suitable for both grid scenarios compared to 0.2 C. It makes the dispatch strategy design easier in commercial practices that there are a few very good candidate dispatch solutions with system NPC values close to that of the optimal solution for both UEG scenarios in CAR and CR.

Excess S-adenosylmethionine reroutes phosphatidylethanolamine towards phosphatidylcholine and triglyceride synthesis

PubMed Central

Martínez-Uña, Maite; Varela-Rey, Marta; Cano, Ainara; Fernández-Ares, Larraitz; Beraza, Naiara; Aurrekoetxea, Igor; Martínez-Arranz, Ibon; García-Rodríguez, Juan L; Buqué, Xabier; Mestre, Daniela; Luka, Zigmund; Wagner, Conrad; Alonso, Cristina; Finnell, Richard H; Lu, Shelly C; Martínez-Chantar, M Luz; Aspichueta, Patricia; Mato, José M

2013-01-01

Methionine adenosyltransferase 1A (MAT1A) and glycine N-methyltransferase (GNMT) are the primary genes involved in hepatic S-adenosylmethionine (SAMe) synthesis and degradation, respectively. Mat1a ablation in mice induces a decrease in hepatic SAMe, activation of lipogenesis, inhibition of triglyceride (TG) release, and steatosis. Gnmt deficient mice, despite showing a large increase in hepatic SAMe, also develop steatosis. We hypothesized that as an adaptive response to hepatic SAMe accumulation, phosphatidylcholine (PC) synthesis via the phosphatidylethanolamine (PE) N-methyltransferase (PEMT) pathway is stimulated in Gnmt−/− mice. We also propose that the excess PC thus generated is catabolized leading to TG synthesis and steatosis via diglyceride (DG) generation. We observed that Gnmt−/− mice present with normal hepatic lipogenesis and increased TG release. We also observed that the flux from PE to PC is stimulated in the liver of Gnmt−/− mice and that this results in a reduction in PE content and a marked increase in DG and TG. Conversely, reduction of hepatic SAMe following the administration of a methionine deficient diet reverted the flux from PE to PC of Gnmt−/− mice to that of wild type animals and normalized DG and TG content preventing the development of steatosis. Gnmt−/− mice with an additional deletion of perilipin2, the predominant lipid droplet protein, maintain high SAMe levels, with a concurrent increased flux from PE to PC, but do not develop liver steatosis. Conclusion These findings indicate that excess SAMe reroutes PE towards PC and TG synthesis, and lipid sequestration. PMID:23505042

Energy and Cost Optimized Technology Options to Meet Energy Needs of Food Processors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makhmalbaf, Atefe; Srivastava, Viraj; Hoffman, Michael G.

Full Paper Submission for: Combined cooling, heating and electric power (CCHP) distributed generation (DG) systems can provide electric power and, heating and cooling capability to commercial and industrial facilities directly onsite, while increasing energy efficiency, security of energy supply, grid independence and enhancing the environmental and economic situation for the site. Food processing industries often have simultaneous requirements for heat, steam, chilling and electricity making them well suited for the use of such systems to supply base-load or as peak reducing generators enabling reduction of overall energy use intensity. This paper documents analysis from a project evaluating opportunities enabled bymore » CCHPDG for emission and cost reductions and energy storage systems installed onsite at food processing facilities. In addition, this distributed generation coupled with energy storage demonstrates a non-wires solution to delay or eliminate the need for upgrades to electric distribution systems. It was found that a dairy processing plant in the Pacific Northwest currently purchasing 15,000 MWh/yr of electricity and 190,000 MMBtu/yr of gas could be provided with a 1.1 MW CCHP system reducing the amount of electric power purchased to 450 MWh/yr while increasing the gas demand to 255,000 MMBtu/yr. The high percentage of hydro-power in this region resulted in CO2 emissions from CCHP to be higher than that attributed to the electric utility/regional energy mix. The value of this work is in documenting a real-world example demonstrating the value of CCHP to facility owners and financial decision makers to encourage them to more seriously consider CCHP systems when building or upgrading facilities.« less

Additive Effects of Millimeter Waves and 2-Deoxyglucose Co-Exposure on the Human Keratinocyte Transcriptome.

PubMed

Soubere Mahamoud, Yonis; Aite, Meziane; Martin, Catherine; Zhadobov, Maxim; Sauleau, Ronan; Le Dréan, Yves; Habauzit, Denis

2016-01-01

Millimeter Waves (MMW) will be used in the next-generation of high-speed wireless technologies, especially in future Ultra-Broadband small cells in 5G cellular networks. Therefore, their biocompatibilities must be evaluated prior to their massive deployment. Using a microarray-based approach, we analyzed modifications to the whole genome of a human keratinocyte model that was exposed at 60.4 GHz-MMW at an incident power density (IPD) of 20 mW/cm2 for 3 hours in athermic conditions. No keratinocyte transcriptome modifications were observed. We tested the effects of MMWs on cell metabolism by co-treating MMW-exposed cells with a glycolysis inhibitor, 2-deoxyglucose (2dG, 20 mM for 3 hours), and whole genome expression was evaluated along with the ATP content. We found that the 2dG treatment decreased the cellular ATP content and induced a high modification in the transcriptome (632 coding genes). The affected genes were associated with transcriptional repression, cellular communication and endoplasmic reticulum homeostasis. The MMW/2dG co-treatment did not alter the keratinocyte ATP content, but it did slightly alter the transcriptome, which reflected the capacity of MMW to interfere with the bioenergetic stress response. The RT-PCR-based validation confirmed 6 MMW-sensitive genes (SOCS3, SPRY2, TRIB1, FAM46A, CSRNP1 and PPP1R15A) during the 2dG treatment. These 6 genes encoded transcription factors or inhibitors of cytokine pathways, which raised questions regarding the potential impact of long-term or chronic MMW exposure on metabolically stressed cells.

Chebyshev polynomial filtered subspace iteration in the discontinuous Galerkin method for large-scale electronic structure calculations

DOE PAGES

Banerjee, Amartya S.; Lin, Lin; Hu, Wei; ...

2016-10-21

The Discontinuous Galerkin (DG) electronic structure method employs an adaptive local basis (ALB) set to solve the Kohn-Sham equations of density functional theory in a discontinuous Galerkin framework. The adaptive local basis is generated on-the-fly to capture the local material physics and can systematically attain chemical accuracy with only a few tens of degrees of freedom per atom. A central issue for large-scale calculations, however, is the computation of the electron density (and subsequently, ground state properties) from the discretized Hamiltonian in an efficient and scalable manner. We show in this work how Chebyshev polynomial filtered subspace iteration (CheFSI) canmore » be used to address this issue and push the envelope in large-scale materials simulations in a discontinuous Galerkin framework. We describe how the subspace filtering steps can be performed in an efficient and scalable manner using a two-dimensional parallelization scheme, thanks to the orthogonality of the DG basis set and block-sparse structure of the DG Hamiltonian matrix. The on-the-fly nature of the ALB functions requires additional care in carrying out the subspace iterations. We demonstrate the parallel scalability of the DG-CheFSI approach in calculations of large-scale twodimensional graphene sheets and bulk three-dimensional lithium-ion electrolyte systems. In conclusion, employing 55 296 computational cores, the time per self-consistent field iteration for a sample of the bulk 3D electrolyte containing 8586 atoms is 90 s, and the time for a graphene sheet containing 11 520 atoms is 75 s.« less

Drinking game play among first-year college student drinkers: an event-specific analysis of the risk for alcohol use and problems.

PubMed

Ray, Anne E; Stapleton, Jerod L; Turrisi, Rob; Mun, Eun-Young

2014-09-01

College students who play drinking games (DGs) more frequently report higher levels of alcohol use and experience more alcohol-related harm. However, the extent to which they are at risk for increased consumption and harm as a result of DG play on a given event after accounting for their typical DG participation, and typical and event drinking, is unclear. We examined whether first-year students consumed more alcohol and were more likely to experience consequences on drinking occasions when they played DGs. Participants (n = 336) completed up to six web-based surveys following weekend drinking events in their first semester. Alcohol use, DG play, and consequences were reported for the Friday and Saturday prior to each survey. Typical DG tendencies were controlled in all models. Typical and event alcohol use were controlled in models predicting risk for consequences. Participants consumed more alcohol on DG versus non-DG events. All students were more likely to experience blackout drinking consequences when they played DGs. Women were more likely to experience social-interpersonal consequences when they played DGs. DG play is an event-specific risk factor for increased alcohol use among first-year students, regardless of individual DG play tendencies. Further, event DG play signals increased risk for blackout drinking consequences for all students, and social-interpersonal consequences for women, aside from the amount of alcohol consumed on those occasions as well as typical drinking behaviors. Prevention efforts to reduce high-risk drinking may be strengthened by highlighting both event- and person-specific risks of DG play.

Apigenin-7-diglucuronide protects retinas against bright light-induced photoreceptor degeneration through the inhibition of retinal oxidative stress and inflammation.

PubMed

Bian, Minjuan; Zhang, Yong; Du, Xiaoye; Xu, Jing; Cui, Jingang; Gu, Jiangping; Zhu, Weiliang; Zhang, Teng; Chen, Yu

2017-05-15

Vision impairment in retinal degenerative diseases such as age-related macular degeneration is primarily associated with photoreceptor degeneration, in which oxidative stress and inflammatory responses are mechanistically involved as central players. Therapies with photoreceptor protective properties remain to be developed. Apigenin-7-diglucuronide (A7DG), a flavonoid glycoside, is present in an assortment of medicinal plants with anti-inflammatory or ant-oxidant activities. However, the pharmacological significance of A7DG remains unknown in vivo. The current study isolated A7DG from Glechoma longituba (Nakai) Kuprian and investigated the retinal protective effect A7DG in mice characterized by bright light-induced photoreceptor degeneration. The results showed that A7DG treatment led to remarkable photoreceptor protection in bright light-exposed BALB/c mice. Moreover, A7DG treatment alleviated photoreceptor apoptosis, mitigated oxidative stress, suppressed reactive gliosis and microglial activation and attenuated the expression of proinflammatory genes in bright light-exposed retinas. The results demonstrated for the first time remarkable photoreceptor protective activities of A7DG in vivo. Inhibition of bright light-induced retinal oxidative stress and retinal inflammatory responses was associated with the retinal protection conferred by A7DG. The work here warrants further evaluation of A7DG as a pharmacological candidate for the treatment of vision-threatening retinal degenerative disorders. Moreover, given the general implication of oxidative stress and inflammation in the pathogenesis of neurodegeneration, A7DG could be further tested for the treatment of other neurodegenerative disorders. Copyright © 2017 Elsevier B.V. All rights reserved.

Effects of hexagonal boron nitride on dry compression mixture of Avicel DG and Starch 1500.

PubMed

Uğurlu, Timuçin; Halaçoğlu, Mekin Doğa

2016-01-01

The objective of this study was to investigate the lubrication properties of hexagonal boron nitride (HBN) on a (1:1) binary mixture of Avicel DG and Starch 1500 after using the dry granulation-slugging method and compare it with conventional lubricants, such as magnesium stearate (MGST), glyceryl behenate (COMP) and stearic acid (STAC). MGST is one of the most commonly used lubricants in the pharmaceutical industry. However, it has several adverse effects on tablet properties. In our current study, we employed various methods to eradicate the work hardening phenomenon in dry granulation, and used HBN as a new lubricant to overcome the adverse effects of other lubricants on tablet properties. HBN was found to be as effective as MGST and did not show any significant adverse effects on the crushing strength or work hardening. From the scanning electron microscope (SEM) images, it was concluded that HBN distributed better than MGST. As well as showing better distribution, HBN's effect on disintegration was the least pronounced. Semi-quantitative weight percent distribution of B and N elements in the tablets was obtained using EDS (energy dispersive spectroscopy). Based on atomic force microscope (AFM) surface roughness images, formulations prepared with 1% HBN showed better plastic character than those prepared with MGST.

Hexose transport by brain slices: further studies on energy dependence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kyle-Lillegard, J.; Gold, B.I.

1983-04-01

We studied the uptake of (/sup 3/H)2-deoxyglucose ((/sup 3/H)2DG) by slices of rat cerebral cortex in vitro as a model of glucose transport by brain. Slices were incubated with (/sup 3/H)2DG, or with L-(/sup 3/H)glucose as a marker for diffusion; the difference between (/sup 3/H)2DG uptake and L-(/sup 3/H)glucose uptake was defined as net (/sup 3/H)2DG transport. Net (/sup 3/H)2DG transport was a function of incubation temperature, with an estimated temperature coefficient of 1.87 from 15 degrees C to 25 degrees C. The net uptake of (/sup 3/H)2DG was not inhibited by phlorizin or phloretin in concentrations well above themore » reported Ki of these inhibitors for hexose uptake in other systems. To examine the hypothesis that (/sup 3/H)2DG transport by brain slices is dependent on mitochondrial energy, we studied net (/sup 3/H)2DG uptake by slices which had been preincubated in media designed to alter intracellular ATP stores. The transport process was very sensitive to inhibition by DNP, but the correlation between (/sup 3/H)2DG transport and ATP levels was unclear. In contrast to our published hypothesis that the transport process required mitochondrial energy, these data indicate that dependence on energy is not absolute.« less

THE CO2 ABATEMENT POTENTIAL OF CALIFORNIA'S MID-SIZED COMMERCIAL BUILDINGS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stadler, Michael; Marnay, Chris; Cardoso, Goncalo

2009-12-31

The Ernest Orlando Lawrence Berkeley National Laboratory (LBNL) is working with the California Energy Commission (CEC) todetermine the potential role of commercial sector distributed generation (DG) with combined heat and power (CHP) capability deployment in greenhouse gas emissions (GHG) reductions. CHP applications at large industrial sites are well known, and a large share of their potential has already been harvested. In contrast, relatively little attention has been paid to the potential of medium-sized commercial buildings, i.e. ones with peak electric loads ranging from 100 kW to 5 MW. We examine how this sector might implement DG with CHP in costmore » minimizing microgrids that are able to adopt and operate various energy technologies, such as solar photovoltaics (PV), on-site thermal generation, heat exchangers, solar thermal collectors, absorption chillers, and storage systems. We apply a mixed-integer linear program (MILP) that minimizes a site?s annual energy costs as its objective. Using 138 representative mid-sized commercial sites in California (CA), existing tariffs of three major electricity distribution ultilities, and performance data of available technology in 2020, we find the GHG reduction potential for this CA commercial sector segment, which represents about 35percent of total statewide commercial sector sales. Under the assumptions made, in a reference case, this segment is estimated to be capable of economically installing 1.4 GW of CHP, 35percent of the California Air Resources Board (CARB) statewide 4 GW goal for total incremental CHP deployment by 2020. However, because CARB?s assumed utilization is far higher than is found by the MILP, the adopted CHP only contributes 19percent of the CO2 target. Several sensitivity runs were completed. One applies a simple feed-in tariff similar to net metering, and another includes a generous self-generation incentive program (SGIP) subsidy for fuel cells. The feed-in tariff proves ineffective at stimulating CHP deployment, while the SGIP buy down is more powerful. The attractiveness of CHP varies widely by climate zone and service territory, but in general, hotter inlandareas and San Diego are the more attractive regions because high cooling loads achieve higher equipment utilization. Additionally, large office buildings are surprisingly good hosts for CHP, so large office buildings in San Diego and hotter urban centers emerge as promising target hosts. Overall the effect on CO2 emissions is limited, never exceeding 27 percent of the CARB target. Nonetheless, results suggest that the CO2 emissions abatement potential of CHP in mid-sized CA buildings is significant, and much more promising than is typically assumed.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colvin, Robert A.; Jin, Qiaoling; Lai, Barry

Increasing evidence suggests that metal dyshomeostasis plays an important role in human neurodegenerative diseases. Although distinctive metal distributions are described for mature hippocampus and cortex, much less is known about metal levels and intracellular distribution in individual hippocampal neuronal somata. To solve this problem, we conducted quantitative metal analyses utilizing synchrotron radiation X-Ray fluorescence on frozen hydrated primary cultured neurons derived from rat embryonic cortex (CTX) and two regions of the hippocampus: dentate gyrus (DG) and CA1. Also, comparing average metal contents showed that the most abundant metals were calcium, iron, and zinc, whereas metals such as copper and manganesemore » were less than 10% of zinc. Average metal contents were generally similar when compared across neurons cultured from CTX, DG, and CA1, except for manganese that was larger in CA1. However, each metal showed a characteristic spatial distribution in individual neuronal somata. Zinc was uniformly distributed throughout the cytosol, with no evidence for the existence of previously identified zinc-enriched organelles, zincosomes. Calcium showed a peri-nuclear distribution consistent with accumulation in endoplasmic reticulum and/or mitochondria. Iron showed 2-3 distinct highly concentrated puncta only in peri-nuclear locations. Notwithstanding the small sample size, these analyses demonstrate that primary cultured neurons show characteristic metal signatures. The iron puncta probably represent iron-accumulating organelles, siderosomes. Thus, the metal distributions observed in mature brain structures are likely the result of both intrinsic neuronal factors that control cellular metal content and extrinsic factors related to the synaptic organization, function, and contacts formed and maintained in each region.« less

Comparison of (/sup 14/C)glucose and (/sup 14/C)deoxyglucose as tracers of brain glucose use

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hawkins, R.A.; Mans, A.M.; Davis, D.W.

1988-03-01

Because glucose metabolism and functional activity in brain regions are normally coupled, knowledge of regional brain glucose use can yield insights into regional functional activity. The deoxyglucose (DG) method is widely used for this purpose in experimental animals and humans but questions have arisen regarding its limits and accuracy. Therefore an experiment was designed to compare the DG method on a structure-by-structure basis with another tracer of glucose use, (6-/sup 14/C)glucose, in normal rats. The cerebral metabolic rates obtained using the two tracers were similar in the telencephalon, but the results using DG were substantially lower in the midbrain andmore » hindbrain (diencephalon, 18%; mesencephalon, 20%; metencephalon, 29%; and myelencephalon, 35%). The primary DG metabolite, DG 6-phosphate (DG-6-P) was found to disappear in a non-uniform manner from the major brain structures: telencephalon less than diencephalon less than mesencephalon = metencephalon less than myelencephalon. Thus a correlation was found between the rate of DG-6-P loss and the extent to which the DG method gave lower values of glucose use. Thus this may explain, at least in part, the discrepancies between the two methods.« less

77 FR 54619 - Exelon Generation Company, LLC., Receipt of Request for Action

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-05

... because the combustion air can be diluted with steam. Although the combustion air is drawn from an air... certain conditions, the ventilation damper alignment is such that steam that enters the DG room from the... substantially exceeded. There has been no structured and detailed review of the licensing requirements for HELB...

Modeling and Simulation of a DG-Integrated Intelligent Microgrid

DTIC Science & Technology

2010-02-01

17. The I-V curve from the manufacturer for BP-4175 175W PV module...........................32   Fig. 18. Wind turbine model...33   Fig. 19. Electrical outputs of wind turbine... PMSG : Permanent Magnet Synchronous Generator PLL : Phase Lock Loop PV : Photovoltaic PWM : Pulse Width Modulation TOU : Time of Use VTES

Results From The Salt Disposition Project Next Generation Solvent Demonstration Plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, T. B.; Fondeur, F. F.; Taylor-Pashow, K. M.L.

2014-04-02

Strip Effluent Hold Tank (SEHT), Decontaminated Salt Solution Hold Tank (DSSHT), Caustic Wash Tank (CWT) and Solvent Hold Tank (SHT) samples were taken throughout the Next Generation Solvent (NGS) Demonstration Plan. These samples were analyzed and the results are reported. SHT: The solvent behaved as expected, with no bulk changes in the composition over time, with the exception of the TOA and TiDG. The TiDG depletion is higher than expected, and consideration must be taken on the required rate of replenishment. Monthly sampling of the SHT is warranted. If possible, additional SHT samples for TiDG analysis (only) would help SRNLmore » refine the TiDG degradation model. CWT: The CWT samples show the expected behavior in terms of bulk chemistry. The 137Cs deposited into the CWT varies somewhat, but generally appears to be lower than during operations with the BOBCalix solvent. While a few minor organic components were noted to be present in the Preliminary sample, at this time these are thought to be artifacts of the sample preparation or may be due to the preceding solvent superwash. DSSHT: The DSSHT samples show the predicted bulk chemistry, although they point towards significant dilution at the front end of the Demonstration. The 137Cs levels in the DSSHT are much lower than during the BOBCalix operations, which is the expected observation. SEHT: The SEHT samples represent the most different output of all four of the outputs from MCU. While the bulk chemistry is as expected, something is causing the pH of the SEHT to be higher than what would be predicted from a pure stream of 0.01 M boric acid. There are several possible different reasons for this, and SRNL is in the process of investigating. Other than the pH issue, the SEHT is as predicted. In summary, the NGS Demonstration Plan samples indicate that the MCU system, with the Blend Solvent, is operating as expected. The only issue of concern regards the pH of the SEHT, and SRNL is in the process of investigating this. SRNL results support the transition to routine operations.« less

Guide to the Identification and Geographic Distribution of Lutzomyia Sand Flies in Mexico, the West Indies, Central and South America (Diptera:Psychodidae)

DTIC Science & Technology

1994-03-31

shown arising from the paramere by Ryan (1986). We studied other males from Amazonas, Brazil (Labrea, Oct. 1972, D.G. Young), and Madre de Dios , Peru...aided ident.). Distribution (Map 59). FRENCH GUIANA (Pajot & Le Pont 1978); PERU (6, 9, Madre de Dios , Tambopata Reserve, canopy fogging collections...with L. brasiliensis or another aragaoi group species. Young et al. (1985) reported L. brasiliensis (1 6) from Tambopata Reserve, Madre de Dios , Peru

Dentate Gyrus Contributes to Retrieval as well as Encoding: Evidence from Context Fear Conditioning, Recall, and Extinction.

PubMed

Bernier, Brian E; Lacagnina, Anthony F; Ayoub, Adam; Shue, Francis; Zemelman, Boris V; Krasne, Franklin B; Drew, Michael R

2017-06-28

Dentate gyrus (DG) is widely thought to provide a teaching signal that enables hippocampal encoding of memories, but its role during retrieval is poorly understood. Some data and models suggest that DG plays no role in retrieval; others encourage the opposite conclusion. To resolve this controversy, we evaluated the effects of optogenetic inhibition of dorsal DG during context fear conditioning, recall, generalization, and extinction in male mice. We found that (1) inhibition during training impaired context fear acquisition; (2) inhibition during recall did not impair fear expression in the training context, unless mice had to distinguish between similar feared and neutral contexts; (3) inhibition increased generalization of fear to an unfamiliar context that was similar to a feared one and impaired fear expression in the conditioned context when it was similar to a neutral one; and (4) inhibition impaired fear extinction. These effects, as well as several seemingly contradictory published findings, could be reproduced by BACON (Bayesian Context Fear Algorithm), a physiologically realistic hippocampal model positing that acquisition and retrieval both involve coordinated activity in DG and CA3. Our findings thus suggest that DG contributes to retrieval and extinction, as well as to the initial establishment of context fear. SIGNIFICANCE STATEMENT Despite abundant evidence that the hippocampal dentate gyrus (DG) plays a critical role in memory, it remains unclear whether the role of DG relates to memory acquisition or retrieval. Using contextual fear conditioning and optogenetic inhibition, we show that DG contributes to both of these processes. Using computational simulations, we identify specific mechanisms through which the suppression of DG affects memory performance. Finally, we show that DG contributes to fear extinction learning, a process in which learned fear is attenuated through exposures to a fearful context in the absence of threat. Our data resolve a long-standing question about the role of DG in memory and provide insight into how disorders affecting DG, including aging, stress, and depression, influence cognitive processes. Copyright © 2017 the authors 0270-6474/17/376359-13$15.00/0.

Hematinic deficiencies and anemia statuses in antigastric parietal cell antibody-positive erosive oral lichen planus patients with desquamative gingivitis.

PubMed

Chang, Julia Yu-Fong; Wang, Yi-Ping; Wu, Yang-Che; Wu, Yu-Hsueh; Tseng, Chih-Huang; Sun, Andy

2016-10-01

Erosive oral lichen planus (EOLP) patients with desquamative gingivitis (DG) are sometimes encountered in our oral mucosal disease clinic. This study assessed hematinic deficiencies and anemia statuses in antigastric parietal cell antibody (GPCA)-positive EOLP patients with DG (GPCA + /DG + /EOLP patients). The blood hemoglobin, iron, vitamin B12, folic acid, and homocysteine concentrations and serum GPCA levels in 92 GPCA + /DG + /EOLP patients and 184 age- and sex-matched healthy controls were measured and compared between the two groups. We found that 27 (29.3%), 16 (17.4%), and 27 (29.3%) of 92 GPCA + /DG + /EOLP patients had hemoglobin (men < 13 g/dL and women < 12 g/dL), iron (< 60 μg/dL), and vitamin B12 (< 200 pg/mL) deficiencies, respectively. Moreover, 37 (40.2%) of 92 GPCA + /DG + /EOLP patients had an abnormally high blood homocysteine level (> 12.1μM). GPCA + /DG + /EOLP patients had a significantly higher frequency of hemoglobin, iron, or vitamin B12 deficiency and an abnormally high blood homocysteine level than healthy control individuals (all p < 0.001). Of 27 anemic GPCA + /DG + /EOLP patients, 13 (48.2%) had pernicious anemia, five (18.5%) had iron deficiency anemia, one (3.7%) had thalassemia trait, and the remaining eight (29.6%) had normocytic anemia. Moreover, of the 92 GPCA + /DG + /EOLP patients, 24 had macrocytosis, and only 13 (54.2%) of these 24 patients had pernicious anemia. We conclude that GPCA + /DG + /EOLP patients may have vitamin B12 deficiency, iron deficiency, and an abnormally high blood homocysteine level. In addition to pernicious anemia, GPCA + /DG + /EOLP patients may sometimes have normocytic anemia or iron deficiency anemia. Copyright © 2016. Published by Elsevier B.V.

Is Monoglucosyldiacylglycerol a Precursor to Monogalactosyldiacylglycerol in All Cyanobacteria?

PubMed

Sato, Naoki

2015-10-01

Monogalactosyldiacylglycerol (MGDG) is ubiquitous in the photosynthetic membranes of cyanobacteria and chloroplasts. It is synthesized by galactosylation of diacylglycerol (DAG) in the chloroplasts, whereas it is produced by epimerization of monoglucosyldiacylglycerol (GlcDG) in at least several cyanobacteria that have been analyzed such as Synechocystis sp. PCC 6803. A previous study, however, showed that the mgdE gene encoding the epimerase is absent in some cyanobacteria such as Gloeobacter violaceus, Thermosynechococcus elongatus and Acaryochloris marina. In addition, the N-terminal 'fatty acid hydroxylase' domain is lacking in the MgdE protein of Prochlorococcus marinus. These problems may cast doubt upon the general (or exclusive) role of MgdE in the epimerization of GlcDG to MGDG in cyanobacteria. In addition, GlcDG is usually present at a very low level, and the structural determination of endogenous GlcDG has not been accomplished with cyanobacterial samples. In this study, I determined the structure of GlcDG from Anabaena variabilis by (1)H- and (13)C-nuclear magnetic resonance (NMR) spectroscopy. I then showed that G. violaceus, T. elongatus, A. marina and P. marinus contain GlcDG. In all cases, GlcDG consisted of fewer unsaturated molecular species than MGDG, providing further evidence that GlcDG is a precursor to MGDG. The conversion of GlcDG to MGDG was also demonstrated by radiolabeling and chase experiments in G. violaceus and P. marinus. These results demonstrate that all the analyzed cyanobacteria contain GlcDG, which is converted to MGDG, and suggest that an alternative epimerase is required for MGDG synthesis in these cyanobacteria. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

The enzymatic processing of α-dystroglycan by MMP-2 is controlled by two anchoring sites distinct from the active site

PubMed Central

Fasciglione, Giovanni Francesco; Sbardella, Diego; Sciandra, Francesca; Casella, MariaLuisa; Camerini, Serena; Crescenzi, Marco; Gori, Alessandro; Tarantino, Umberto; Cozza, Paola; Brancaccio, Andrea; Coletta, Massimo; Bozzi, Manuela

2018-01-01

Dystroglycan (DG) is a membrane receptor, belonging to the dystrophin-glycoprotein complex (DGC) and formed by two subunits, α-dystroglycan (α-DG) and β-dystroglycan (β -DG). The C-terminal domain of α-DG and the N-terminal extracellular domain of β -DG are connected, providing a link between the extracellular matrix and the cytosol. Under pathological conditions, such as cancer and muscular dystrophies, DG may be the target of metalloproteinases MMP-2 and MMP-9, contributing to disease progression. Previously, we reported that the C-terminal domain α-DG (483–628) domain is particularly susceptible to the catalytic activity of MMP-2; here we show that the α-DG 621–628 region is required to carry out its complete digestion, suggesting that this portion may represent a MMP-2 anchoring site. Following this observation, we synthesized an α-DG based-peptide, spanning the (613–651) C-terminal region. The analysis of the kinetic and thermodynamic parameters of the whole and the isolated catalytic domain of MMP-2 (cdMMP-2) has shown its inhibitory properties, indicating the presence of (at least) two binding sites for the peptide, both located within the catalytic domain, only one of the two being topologically distinct from the catalytic active groove. However, the different behavior between whole MMP-2 and cdMMP-2 envisages the occurrence of an additional binding site for the peptide on the hemopexin-like domain of MMP-2. Interestingly, mass spectrometry analysis has shown that α-DG (613–651) peptide is cleavable even though it is a very poor substrate of MMP-2, a feature that renders this molecule a promising template for developing a selective MMP-2 inhibitor. PMID:29447293

A high order compact least-squares reconstructed discontinuous Galerkin method for the steady-state compressible flows on hybrid grids

NASA Astrophysics Data System (ADS)

Cheng, Jian; Zhang, Fan; Liu, Tiegang

2018-06-01

In this paper, a class of new high order reconstructed DG (rDG) methods based on the compact least-squares (CLS) reconstruction [23,24] is developed for simulating the two dimensional steady-state compressible flows on hybrid grids. The proposed method combines the advantages of the DG discretization with the flexibility of the compact least-squares reconstruction, which exhibits its superior potential in enhancing the level of accuracy and reducing the computational cost compared to the underlying DG methods with respect to the same number of degrees of freedom. To be specific, a third-order compact least-squares rDG(p1p2) method and a fourth-order compact least-squares rDG(p2p3) method are developed and investigated in this work. In this compact least-squares rDG method, the low order degrees of freedom are evolved through the underlying DG(p1) method and DG(p2) method, respectively, while the high order degrees of freedom are reconstructed through the compact least-squares reconstruction, in which the constitutive relations are built by requiring the reconstructed polynomial and its spatial derivatives on the target cell to conserve the cell averages and the corresponding spatial derivatives on the face-neighboring cells. The large sparse linear system resulted by the compact least-squares reconstruction can be solved relatively efficient when it is coupled with the temporal discretization in the steady-state simulations. A number of test cases are presented to assess the performance of the high order compact least-squares rDG methods, which demonstrates their potential to be an alternative approach for the high order numerical simulations of steady-state compressible flows.

Beneficial effect of diosgenin as a stimulator of NGF on the brain with neuronal damage induced by Aβ-42 accumulation and neurotoxicant injection.

PubMed

Koh, Eun-Kyoung; Yun, Woo-Bin; Kim, Ji-Eun; Song, Sung-Hwa; Sung, Ji-Eun; Lee, Hyun-Ah; Seo, Eun-Ji; Jee, Seung-Wan; Bae, Chang-Joon; Hwang, Dae-Youn

2016-06-01

To investigate the beneficial effects of diosgenin (DG) on the multiple types of brain damage induced by Aβ-42 peptides and neurotoxicants, alterations in the specific aspects of brain functions were measured in trimethyltin (TMT)-injected transgenic 2576 (TG) mice that had been pretreated with DG for 21 days. Multiple types of damage were successfully induced by Aβ-42 accumulation and TMT injection into the brains of TG mice. However, DG treatment significantly reduced the number of Aβ-stained plaques and dead cells in the granule cells layer of the dentate gyrus. Significant suppression of acetylcholinesterase (AChE) activity and Bax/Bcl-2 expression was also observed in the DG treated TG mice (TG+DG group) when compared with those of the vehicle (VC) treated TG mice (TG+VC group). Additionally, the concentration of nerve growth factor (NGF) was dramatically enhanced in TG+DG group, although it was lower in the TG+VC group than the non-transgenic (nTG) group. Furthermore, the decreased phosphorylation of downstream members in the TrkA high affinity receptor signaling pathway in the TG+VC group was significantly recovered in the TG+DG group. A similar pattern was observed in p75(NTR) expression and JNK phosphorylation in the NGF low affinity receptor signaling pathway. Moreover, superoxide dismutase (SOD) activity was enhanced in the TG+DG group, while the level of malondialdehyde (MDA), a marker of lipid peroxidation, was lower in the TG+DG group than the TG+VC group. These results suggest that DG could exert a wide range of beneficial activities for multiple types of brain damage through stimulation of NGF biosynthesis.

Beneficial effect of diosgenin as a stimulator of NGF on the brain with neuronal damage induced by Aβ-42 accumulation and neurotoxicant injection

PubMed Central

Koh, Eun-Kyoung; Yun, Woo-Bin; Kim, Ji-Eun; Song, Sung-Hwa; Sung, Ji-Eun; Lee, Hyun-Ah; Seo, Eun-Ji; Jee, Seung-Wan

2016-01-01

To investigate the beneficial effects of diosgenin (DG) on the multiple types of brain damage induced by Aβ-42 peptides and neurotoxicants, alterations in the specific aspects of brain functions were measured in trimethyltin (TMT)-injected transgenic 2576 (TG) mice that had been pretreated with DG for 21 days. Multiple types of damage were successfully induced by Aβ-42 accumulation and TMT injection into the brains of TG mice. However, DG treatment significantly reduced the number of Aβ-stained plaques and dead cells in the granule cells layer of the dentate gyrus. Significant suppression of acetylcholinesterase (AChE) activity and Bax/Bcl-2 expression was also observed in the DG treated TG mice (TG+DG group) when compared with those of the vehicle (VC) treated TG mice (TG+VC group). Additionally, the concentration of nerve growth factor (NGF) was dramatically enhanced in TG+DG group, although it was lower in the TG+VC group than the non-transgenic (nTG) group. Furthermore, the decreased phosphorylation of downstream members in the TrkA high affinity receptor signaling pathway in the TG+VC group was significantly recovered in the TG+DG group. A similar pattern was observed in p75NTR expression and JNK phosphorylation in the NGF low affinity receptor signaling pathway. Moreover, superoxide dismutase (SOD) activity was enhanced in the TG+DG group, while the level of malondialdehyde (MDA), a marker of lipid peroxidation, was lower in the TG+DG group than the TG+VC group. These results suggest that DG could exert a wide range of beneficial activities for multiple types of brain damage through stimulation of NGF biosynthesis. PMID:27382379

Drinking game play among first-year college student drinkers: An event-specific analysis of the risk for alcohol use and problems

PubMed Central

Ray, Anne E.; Stapleton, Jerod L.; Turrisi, Rob; Mun, Eun-Young

2014-01-01

Background College students who play drinking games (DGs) more frequently report higher levels of alcohol use and experience more alcohol-related harm. However, the extent to which they are at risk for increased consumption and harm as a result of DG play on a given event after accounting for their typical DG participation, and typical and event drinking, is unclear. Objectives We examined whether first-year students consumed more alcohol and were more likely to experience consequences on drinking occasions when they played DGs. Methods Participants (N = 336) completed up to six web-based surveys following weekend drinking events in their first semester. Alcohol use, DG play, and consequences were reported for the Friday and Saturday prior to each survey. Typical DG tendencies were controlled in all models. Typical and event alcohol use were controlled in models predicting risk for consequences. Results Participants consumed more alcohol on DG versus non-DG events. All students were more likely to experience blackout drinking consequences when they played DGs. Women were more likely to experience social-interpersonal consequences when they played DGs. Conclusion DG play is an event-specific risk factor for increased alcohol use among first-year students, regardless of individual DG play tendencies. Further, event DG play signals increased risk for blackout drinking consequences for all students, and social-interpersonal consequences for women, aside from the amount of alcohol consumed on those occasions as well as typical drinking behaviors. Prevention efforts to reduce high-risk drinking may be strengthened by highlighting both event- and person-specific risks of DG play. PMID:25192202

G-CSF and cognitive dysfunction in elderly diabetic mice with cerebral small vessel disease: Preventive intervention effects and underlying mechanisms.

PubMed

Guan, Zhu-Fei; Tao, Ying-Hong; Zhang, Xiao-Ming; Guo, Qi-Lin; Liu, Ying-Chao; Zhang, Yu; Wang, Yan-Mei; Ji, Gang; Wu, Guo-Feng; Wang, Na-Na; Yang, Hao; Yu, Zhong-Yu; Guo, Jing-Chun; Zhou, Hou-Guang

2017-06-01

Although cognitive dysfunction is a common neurological complication in elderly patients with diabetes, the mechanisms underlying this relationship remain unclear, and effective preventive interventions have yet to be developed. Thus, this study investigated the preventive effects and mechanisms of action associated with granulocyte colony-stimulating factor (G-CSF) on cognitive dysfunction in elderly diabetic mice with cerebral small vessel disease. This study included 40 male db/db diabetic and wild-type (WT) mice that were categorized into the following four groups at the age of 3 weeks: db/db group (DG), db/db+G-CSF group (DGG), WT group (WG), and WT+G-CSF group (WGG). The mice were fed normal diets for 4 months and then given G-CSF (75 μg/kg) via intraperitoneal injections for 1 month. At 7.5 months of age, the cognitive abilities of the mice were assessed with the Y-maze test and the Social Choice Test; body weight, blood pressure (BP), and blood glucose measurements were obtained throughout the study. Brain imaging and blood oxygen level-dependent (BOLD) contrast imaging analyses were performed with a small animal magnetic resonance imaging (MRI) system, autophagosome levels were detected with a transmission electron microscope (TEM), hippocampal neurons were assessed with hematoxylin and eosin (HE) staining, and protein expressions and distributions were evaluated using immunohistochemistry and Western blot analyses. (i) The body weight and blood glucose levels of the DG and DGG mice were significantly higher than those of the WG and WGG mice; (ii) social choice and spatial memory capabilities were significantly reduced in DG mice but were recovered by G-CSF in DGG mice; (iii) the MRI scans revealed multiple lacunar lesions and apparent hippocampal atrophy in the brains of DG mice, but G-CSF reduced the number of lacunar lesions and ameliorated hippocampal atrophy; (iv) the MRI-BOLD scans showed a downward trend in whole-brain activity and reductions in the connectivities of the hippocampus and amygdala with subcortical structures in DG mice, but G-CSF clearly improved the altered brain activity as well as the connectivity of the hippocampus in DGG mice; (v) HE staining revealed fewer neurons in the hippocampus in DG mice; (vi) TEM analyses revealed significantly fewer autophagosomes in the hippocampi of DG mice, but G-CSF did not increase these numbers; (vii) there were significant reductions in mechanistic target of rapamycin (mTOR) and LC3-phosphatidylethanolamine conjugate (LC3)-II/I levels in the hippocampi of DG mice, whereas p62 was upregulated, and G-CSF significantly enhanced the levels of Beclin1, mTOR, and LC-II/I in DGG mice; and (viii) G-CSF significantly reversed increases in nuclear factor κB (NF-κB) protein levels in DG but not in WG mice. In this study, aged diabetic mice were prone to cognitive dysfunction and cerebral small vessel disease. However, administration of G-CSF significantly improved cognitive function in elderly db/db diabetic mice, and this change was likely related to the regulation of autophagy and NF-κB signaling pathways. © 2017 John Wiley & Sons Ltd.

Homological dimensions and Van den Bergh isomorphisms for nuclear Fréchet algebras

NASA Astrophysics Data System (ADS)

Pirkovskii, Alexei Yu

2012-08-01

We prove the equation \\operatorname{w{.}dg} A=\\operatorname{w{.}db} A for every nuclear Fréchet-Arens-Michael algebra A of finite weak bidimension, where \\operatorname{w{.}dg} A is the weak global dimension and \\operatorname{w{.}db} A the weak bidimension of A. Assuming that A has a projective bimodule resolution of finite type, we establish the estimate \\operatorname{db}A\\le\\operatorname{dg}A+1, where \\operatorname{dg} A is the global dimension and \\operatorname{db} A the bidimension of A. We also prove that \\operatorname{dg}A=\\operatorname{db}A=\\operatorname{w{.}dg}A=\\operatorname{w{.}db} A=n for all nuclear Fréchet-Arens-Michael algebras satisfying the Van den Bergh conditions \\operatorname{VdB}(n). As an application, we calculate the homological dimensions of smooth and complex-analytic quantum tori.

EPA or DHA enhanced oxidative stress and aging protein expression in brain of d-galactose treated mice.

PubMed

Hsu, Yuan-Man; Yin, Mei-Chin

2016-06-01

Effects of eicosapentaenoic acid (EPA, 20:5) and docosahexaenoic acid (DHA, 22:6) upon fatty acid composition, oxidative and inflammatory factors and aging proteins in brain of d-galactose (DG) treated aging mice were examined. Each fatty acid at 7 mg/kg BW/week was supplied for 8 weeks. Brain aging was induced by DG treatment (100 mg/kg body weight) via daily subcutaneous injection for 8 weeks. DG, EPA and DHA treatments changed brain fatty acid composition. DG down-regulated brain Bcl-2 expression and up-regulated Bax expression. Compared with DG groups, EPA and DHA further enhanced Bax expression. DG decreased glutathione content, increased reactive oxygen species (ROS) and oxidized glutathione (GSSG) production, the intake of EPA or DHA caused greater ROS and GSSG formation. DG treatments up-regulated the protein expression of p47(phox) and gp91(phox), and the intake of EPA or DHA led to greater p47(phox) and gp91(phox) expression. DG increased brain prostaglandin E2 (PGE2) levels, and cyclooxygenase (COX)-2 expression and activity, the intake of EPA or DHA reduced brain COX-2 activity and PGE2 formation. DG enhanced brain p53, p16 and p21 expression. EPA and DHA intake led to greater p21 expression, and EPA only caused greater p53 and p16 expression. These findings suggest that these two PUFAs have toxic effects toward aging brain.

Genetic diversity of avenin-like b genes in Aegilops tauschii Coss.

PubMed

Cao, Dong; Wang, Hongxia; Zhang, Bo; Liu, Baolong; Liu, Dengcai; Chen, Wenjie; Zhang, Huaigang

2018-02-01

Avenin-like storage proteins influence the rheological properties and processing quality in common wheat, and the discovery of new alleles will benefit wheat quality improvement. In this study, 13 avenin-like b alleles (TaALPb7D-A-M) were discovered in 108 Aegilops tauschii Coss. accessions. Ten alleles were reported for the first time, while the remaining three alleles were the same as alleles in other species. A total of 15 nucleotide changes were detected in the 13 alleles, resulting in only 11 amino acid changes because of synonymous mutations. Alleles TaALPb7D-E, TaALPb7D-G, and TaALPb7D-J encoded the same protein. These polymorphic sites existed in the N-terminus, Repetitive region (Left), Repetitive region (Right) and C-terminus domains, with no polymorphisms in the signal peptide sequence nor in those encoding the 18 conserved cysteine residues. Phylogenetic analysis divided the TaALPb7Ds into four clades. The Ae. tauschii alleles were distributed in all four clades, while the alleles derived from common wheat, TaALPb7D-G and TaALPb7D-C, belonged to clade III and IV, respectively. Alleles TaALPb7D-G and TaALPb7D-C were the most widely distributed, being present in nine and six countries, respectively. Iran and Turkey exhibited the highest genetic diversity with respect to TaALPb7D alleles, accessions from these countries carrying seven and six alleles, respectively, which implied that these countries were the centers of origin of the avenin-like b gene. The new alleles discovered and the phylogenetic analysis of avenin-like b genes will provide breeding materials and a theoretical basis for wheat quality improvement.

Droop Control of Solar PV, Grid and Critical Load using Suppressing DC Current Injection Technique without Battery Storage

NASA Astrophysics Data System (ADS)

Dama Mr., Jayachandra; (Mrs. , Lini Mathew, Dr.; Srikanth Mr., G.

2017-08-01

This paper presents design of a sustainable solar Photo voltaic system for an Indian cities based residential/community house, integrated with grid, supporting it as supplementary sources, to meet energy demand of domestic loads. The role of renewable energy sources in Distributed Generation (DG) is increasingly being recognized as a supplement and an alternative to large conventional central power supply. Though centralized economic system that solely depends on cities is hampered due to energy deficiency, the use of solar energy in cities is never been tried widely due to technical inconvenience and high installation cost. To mitigate these problems, this paper proposes an optimized design of grid-tied PV system without storage which is suitable for Indian origin as it requires less installallation cost and supplies residential loads when the grid power is unavailable. The energy requirement is mainly fulfilled from PV energy module for critical load of a city located residential house and supplemented by grid/DG for base and peak load. The system has been developed for maximum daily household demand of 50kWp and can be scaled to any higher value as per requirement of individual/community building ranging from 50kWp to 60kWp as per the requirement. A simplified control system model has been developed to optimize and control flow of power from these sources. The simulation work, using MATLAB Simulink software for proposed energy management, has resulted in an optimal yield leading efficient power flow control of proposed system.

The Effect of Glycolytic Modulation on Prostate Cancer

DTIC Science & Technology

2010-07-01

this paradigm in the clinic, we completed a phase I study of 2-deoxyglucose (2DG), and assessed 2DG uptake with fluorodeoxyglucose (FDG) positron ...efficacy. In vitro studies with 2DG have demonstrated activity in osteosarcoma cells that were defective in oxidative phosphorylation implying that cells...diagnostic studies developing positron emission tomography (PET), which uses a trapped glucose analogue, 2-deoxy-D-glucose (2DG), for detec- tion of

An Investigation of Run-Time Operations in a Heterogeneous Desktop Grid Environment: The Texas Tech University Desktop Grid Case Study

ERIC Educational Resources Information Center

Perez, Jerry F.

2013-01-01

The goal of the dissertation study was to evaluate the existing DG scheduling algorithm. The evaluation was developed through previously explored simulated analyses of DGs performed by researchers in the field of DG scheduling optimization and to improve the current RT framework of the DG at TTU. The author analyzed the RT of an actual DG, thereby…

Dual-scale Galerkin methods for Darcy flow

NASA Astrophysics Data System (ADS)

Wang, Guoyin; Scovazzi, Guglielmo; Nouveau, Léo; Kees, Christopher E.; Rossi, Simone; Colomés, Oriol; Main, Alex

2018-02-01

The discontinuous Galerkin (DG) method has found widespread application in elliptic problems with rough coefficients, of which the Darcy flow equations are a prototypical example. One of the long-standing issues of DG approximations is the overall computational cost, and many different strategies have been proposed, such as the variational multiscale DG method, the hybridizable DG method, the multiscale DG method, the embedded DG method, and the Enriched Galerkin method. In this work, we propose a mixed dual-scale Galerkin method, in which the degrees-of-freedom of a less computationally expensive coarse-scale approximation are linked to the degrees-of-freedom of a base DG approximation. We show that the proposed approach has always similar or improved accuracy with respect to the base DG method, with a considerable reduction in computational cost. For the specific definition of the coarse-scale space, we consider Raviart-Thomas finite elements for the mass flux and piecewise-linear continuous finite elements for the pressure. We provide a complete analysis of stability and convergence of the proposed method, in addition to a study on its conservation and consistency properties. We also present a battery of numerical tests to verify the results of the analysis, and evaluate a number of possible variations, such as using piecewise-linear continuous finite elements for the coarse-scale mass fluxes.

Role of dystroglycan in limiting contraction-induced injury to the sarcomeric cytoskeleton of mature skeletal muscle.

PubMed

Rader, Erik P; Turk, Rolf; Willer, Tobias; Beltrán, Daniel; Inamori, Kei-Ichiro; Peterson, Taylor A; Engle, Jeffrey; Prouty, Sally; Matsumura, Kiichiro; Saito, Fumiaki; Anderson, Mary E; Campbell, Kevin P

2016-09-27

Dystroglycan (DG) is a highly expressed extracellular matrix receptor that is linked to the cytoskeleton in skeletal muscle. DG is critical for the function of skeletal muscle, and muscle with primary defects in the expression and/or function of DG throughout development has many pathological features and a severe muscular dystrophy phenotype. In addition, reduction in DG at the sarcolemma is a common feature in muscle biopsies from patients with various types of muscular dystrophy. However, the consequence of disrupting DG in mature muscle is not known. Here, we investigated muscles of transgenic mice several months after genetic knockdown of DG at maturity. In our study, an increase in susceptibility to contraction-induced injury was the first pathological feature observed after the levels of DG at the sarcolemma were reduced. The contraction-induced injury was not accompanied by increased necrosis, excitation-contraction uncoupling, or fragility of the sarcolemma. Rather, disruption of the sarcomeric cytoskeleton was evident as reduced passive tension and decreased titin immunostaining. These results reveal a role for DG in maintaining the stability of the sarcomeric cytoskeleton during contraction and provide mechanistic insight into the cause of the reduction in strength that occurs in muscular dystrophy after lengthening contractions.

Design and optimization analysis of dual material gate on DG-IMOS

NASA Astrophysics Data System (ADS)

Singh, Sarabdeep; Raman, Ashish; Kumar, Naveen

2017-12-01

An impact ionization MOSFET (IMOS) is evolved for overcoming the constraint of less than 60 mV/decade sub-threshold slope (SS) of conventional MOSFET at room temperature. In this work, first, the device performance of the p-type double gate impact ionization MOSFET (DG-IMOS) is optimized by adjusting the device design parameters. The adjusted parameters are ratio of gate and intrinsic length, gate dielectric thickness and gate work function. Secondly, the DMG (dual material gate) DG-IMOS is proposed and investigated. This DMG DG-IMOS is further optimized to obtain the best possible performance parameters. Simulation results reveal that DMG DG-IMOS when compared to DG-IMOS, shows better I ON, I ON/I OFF ratio, and RF parameters. Results show that by properly tuning the lengths of two materials at a ratio of 1.5 in DMG DG-IMOS, optimized performance is achieved including I ON/I OFF ratio of 2.87 × 109 A/μm with I ON as 11.87 × 10-4 A/μm and transconductance of 1.06 × 10-3 S/μm. It is analyzed that length of drain side material should be greater than the length of source side material to attain the higher transconductance in DMG DG-IMOS.

A Functional Iron Oxide Nanoparticles Modified with PLA-PEG-DG as Tumor-Targeted MRI Contrast Agent.

PubMed

Xiong, Fei; Hu, Ke; Yu, Haoli; Zhou, Lijun; Song, Lina; Zhang, Yu; Shan, Xiuhong; Liu, Jianping; Gu, Ning

2017-08-01

Tumor targeting could greatly promote the performance of magnetic nanomaterials as MRI (Magnetic Resonance Imaging) agent for tumor diagnosis. Herein, we reported a novel magnetic nanoparticle modified with PLA (poly lactic acid)-PEG (polyethylene glycol)-DG (D-glucosamine) as Tumor-targeted MRI Contrast Agent. In this work, we took use of the D-glucose passive targeting on tumor cells, combining it on PLA-PEG through amide reaction, and then wrapped the PLA-PEG-DG up to the Fe 3 O 4 @OA NPs. The stability and anti phagocytosis of Fe 3 O 4 @OA@PLA-PEG-DG was tested in vitro; the MRI efficiency and toxicity was also detected in vivo. These functional magnetic nanoparticles demonstrated good biocompatibility and stability both in vitro and in vivo. Cell experiments showed that Fe 3 O 4 @OA@PLA-PEG-DG nanoparticles exist good anti phagocytosis and high targetability. In vivo MRI images showed that the contrast effect of Fe 3 O 4 @OA@PLA-PEG-DG nanoparticles prevailed over the commercial non tumor-targeting magnetic nanomaterials MRI agent at a relatively low dose. The DG can validly enhance the tumor-targetting effect of Fe 3 O 4 @OA@PLA-PEG nanoparticle. Maybe MRI agents with DG can hold promise as tumor-targetting development in the future.

Efficient construction of unified continuous and discontinuous Galerkin formulations for the 3D Euler equations

NASA Astrophysics Data System (ADS)

Abdi, Daniel S.; Giraldo, Francis X.

2016-09-01

A unified approach for the numerical solution of the 3D hyperbolic Euler equations using high order methods, namely continuous Galerkin (CG) and discontinuous Galerkin (DG) methods, is presented. First, we examine how classical CG that uses a global storage scheme can be constructed within the DG framework using constraint imposition techniques commonly used in the finite element literature. Then, we implement and test a simplified version in the Non-hydrostatic Unified Model of the Atmosphere (NUMA) for the case of explicit time integration and a diagonal mass matrix. Constructing CG within the DG framework allows CG to benefit from the desirable properties of DG such as, easier hp-refinement, better stability etc. Moreover, this representation allows for regional mixing of CG and DG depending on the flow regime in an area. The different flavors of CG and DG in the unified implementation are then tested for accuracy and performance using a suite of benchmark problems representative of cloud-resolving scale, meso-scale and global-scale atmospheric dynamics. The value of our unified approach is that we are able to show how to carry both CG and DG methods within the same code and also offer a simple recipe for modifying an existing CG code to DG and vice versa.

Dunye Guanxinning Improves Acute Myocardial Ischemia-Reperfusion Injury by Inhibiting Neutrophil Infiltration and Caspase-1 Activity

PubMed Central

Zhang, Q. G.; Wang, S. R.; Chen, X. M.; Guo, H. N.

2018-01-01

Acute myocardial infarction is the most serious manifestation of cardiovascular disease, and it is a life-threatening condition. Dunye Guanxinning (DG) is a protective traditional Chinese patent herbal medicine with high clinical efficacy and suitable for the treatment of myocardial infarction. However, the mechanism through which it is beneficial is unclear. In this study, we hypothesized that DG improves acute myocardial ischemia-reperfusion injury by inhibiting neutrophil infiltration and caspase-1 activity. We found that DG administration decreased infarct size and cardiomyocyte apoptosis and improved left ventricular ejection fraction, fractional shortening, end-systolic volume index, end-systolic diameter, and carotid arterial blood flow output in rats. DG administration also improved hemorheological parameters, myocardial damage biomarkers, and oxidative stress indexes. The findings showed that DG administration inhibited neutrophil infiltration and reduced the serum interleukin-1 beta (IL-1β) level and myocardial IL-1β maturation. Moreover, DG administration inhibited caspase-1 activity and activated adenosine monophosphate-activated protein kinase (AMPK) phosphorylation in rat hearts. These results suggested that DG administration inhibits inflammasome activity and IL-1β release through the AMPK pathway. Our findings support the clinical efficacy of DG and partially reveal its mechanism, which is beneficial for understanding the therapeutic effects of this protective traditional Chinese patent drug. PMID:29674944

Epigenetic regulation of starvation-induced autophagy in Drosophila by histone methyltransferase G9a.

PubMed

An, Phan Nguyen Thuy; Shimaji, Kouhei; Tanaka, Ryo; Yoshida, Hideki; Kimura, Hiroshi; Fukusaki, Eiichiro; Yamaguchi, Masamitsu

2017-08-04

Epigenetics is now emerging as a key regulation in response to various stresses. We herein identified the Drosophila histone methyltransferase G9a (dG9a) as a key factor to acquire tolerance to starvation stress. The depletion of dG9a led to high sensitivity to starvation stress in adult flies, while its overexpression induced starvation stress resistance. The catalytic domain of dG9a was not required for starvation stress resistance. dG9a plays no apparent role in tolerance to other stresses including heat and oxidative stresses. Metabolomic approaches were applied to investigate global changes in the metabolome due to the loss of dG9a during starvation stress. The results obtained indicated that dG9a plays an important role in maintaining energy reservoirs including amino acid, trehalose, glycogen, and triacylglycerol levels during starvation. Further investigations on the underlying mechanisms showed that the depletion of dG9a repressed starvation-induced autophagy by controlling the expression level of Atg8a, a critical gene for the progression of autophagy, in a different manner to that in cancer cells. These results indicate a positive role for dG9a in starvation-induced autophagy.

Chill-inducing music enhances altruism in humans

PubMed Central

Fukui, Hajime; Toyoshima, Kumiko

2014-01-01

Music is a universal feature of human cultures, and it has both fascinated and troubled many researchers. In this paper we show through the dictator game (DG) that an individual’s listening to preferred “chill-inducing” music may promote altruistic behavior that extends beyond the bounds of kin selection or reciprocal altruism. Participants were 22 undergraduate and postgraduate students who were divided into two groups, the in-group and the out-group, and they acted as dictators. The dictators listened to their own preferred “chill-inducing” music, to music they disliked, or to silence, and then played the DG. In this hypothetical experiment, the dictators were given real money (which they did not keep) and were asked to distribute it to the recipients, who were presented as stylized images of men and women displayed on a computer screen. The dictators played the DG both before and after listening to the music. Both male and female dictators gave more money after listening to their preferred music and less after listening to the music they disliked, whereas silence had no effect on the allocated amounts. The group to which the recipient belonged did not influence these trends. The results suggest that listening to preferred “chill-inducing” music promotes altruistic behavior. PMID:25389411

Multi-objective route planning for dangerous goods using compromise programming

NASA Astrophysics Data System (ADS)

Li, Rongrong; Leung, Yee

2011-09-01

The transportation of dangerous goods (DG) can significantly affect the human and natural environment if accidents occur during the transportation process. Hong Kong is a large city with high population density and narrow streets. Due to the land constraints, vehicles carrying DG inevitably have to pass through densely populated areas or their vicinities. Therefore, safe DG transportation is of paramount importance. There is thus an urgent need to review and improve the way trucks carrying DG are being routed on the road networks. Routing of such vehicles should consider not only the operating cost, but also the safety of travelers in the network, the population potentially exposed, and the possible damage inflicted to the surrounding properties and facilities in the event of a DG incident. This research develops a novel methodology for the determination of optimal routes for DG transportation under conflicting objectives by means of the compromise programming approach. With the support of geographical information system (GIS), a case study is carried out for the transportation of DG in the road network of Hong Kong. The experimental results confirm the effectiveness of the proposed approach.

An adhesome comprising laminin, dystroglycan and myosin IIA is required during notochord development in Xenopus laevis.

PubMed

Buisson, Nicolas; Sirour, Cathy; Moreau, Nicole; Denker, Elsa; Le Bouffant, Ronan; Goullancourt, Aline; Darribère, Thierry; Bello, Valérie

2014-12-01

Dystroglycan (Dg) is a transmembrane receptor for laminin that must be expressed at the right time and place in order to be involved in notochord morphogenesis. The function of Dg was examined in Xenopus laevis embryos by knockdown of Dg and overexpression and replacement of the endogenous Dg with a mutated form of the protein. This analysis revealed that Dg is required for correct laminin assembly, for cell polarization during mediolateral intercalation and for proper differentiation of vacuoles. Using mutations in the cytoplasmic domain, we identified two sites that are involved in cell polarization and are required for mediolateral cell intercalation, and a site that is required for vacuolation. Furthermore, using a proteomic analysis, the cytoskeletal non-muscle myosin IIA has been identified for the first time as a molecular link between the Dg-cytoplasmic domain and cortical actin. The data allowed us to identify the adhesome laminin-Dg-myosin IIA as being required to maintain the cortical actin cytoskeleton network during vacuolation, which is crucial to maintain the shape of notochordal cells. © 2014. Published by The Company of Biologists Ltd.

New Structural and Functional Contexts of the Dx[DN]xDG Linear Motif: Insights into Evolution of Calcium-Binding Proteins

PubMed Central

Rigden, Daniel J.; Woodhead, Duncan D.; Wong, Prudence W. H.; Galperin, Michael Y.

2011-01-01

Binding of calcium ions (Ca2+) to proteins can have profound effects on their structure and function. Common roles of calcium binding include structure stabilization and regulation of activity. It is known that diverse families – EF-hands being one of at least twelve – use a Dx[DN]xDG linear motif to bind calcium in near-identical fashion. Here, four novel structural contexts for the motif are described. Existing experimental data for one of them, a thermophilic archaeal subtilisin, demonstrate for the first time a role for Dx[DN]xDG-bound calcium in protein folding. An integrin-like embedding of the motif in the blade of a β-propeller fold – here named the calcium blade – is discovered in structures of bacterial and fungal proteins. Furthermore, sensitive database searches suggest a common origin for the calcium blade in β-propeller structures of different sizes and a pan-kingdom distribution of these proteins. Factors favouring the multiple convergent evolution of the motif appear to include its general Asp-richness, the regular spacing of the Asp residues and the fact that change of Asp into Gly and vice versa can occur though a single nucleotide change. Among the known structural contexts for the Dx[DN]xDG motif, only the calcium blade and the EF-hand are currently found intracellularly in large numbers, perhaps because the higher extracellular concentration of Ca2+ allows for easier fixing of newly evolved motifs that have acquired useful functions. The analysis presented here will inform ongoing efforts toward prediction of similar calcium-binding motifs from sequence information alone. PMID:21720552

Soil organic matter dynamics under different land-use in grasslands in Inner Mongolia (northern China)

NASA Astrophysics Data System (ADS)

Zhao, L.; Wu, W.; Xu, X.; Xu, Y.

2014-04-01

We examined bulk soil properties and molecular biomarker distributions in surface soils from Inner Mongolia grasslands in order to understand the responses of soil organic matter to different land-use. The total of sixteen soils were collected from severely degraded grassland by overgrazing (DG), native grassland without apparent anthropogenic disturbance (NG), groundwater-sustaining grassland (GG) and restored grassland from previous potato cropland (RG). Compared to NG, soil organic carbon content was lower by 50% in DG, but higher by six-fold in GG and one-fold in RG. The δ13C values of soil organic carbon were -24.2 ± 0.6‰ in DG, -24.9 ± 0.6‰ in NG, -25.1 ± 0.1‰ in RG and -26.2 ± 0.6‰ in GG, reflecting different degradation degrees of soil organic matter or different water use efficiencies. The soils in DG contained the lowest abundance of aliphatic lipids (n-alkanes, n-alkanols, n-alkanoic acids, ω-hydroxylalkanoic acids and α-hydroxylalkanoic acids) and lignin-phenols, suggesting selective removal of these biochemically recalcitrant biomarkers with grassland degradation by microbial respiration or wind erosion. Compared to NG, the soils in GG and RG increased ω-hydroxylalkanoic acids by 60-70%, a biomarker for suberin from roots, and increased α-hydroxylalkanoic acids by 10-20%, a biomarker for both cutin and suberin. Our results demonstrate that the groundwater supply and cultivation-restoration practices in Inner Mongolia grasslands not only enhance soil organic carbon sequestration, but also change the proportions of shoot vs. root-derived carbon in soils. This finding has important implications for global carbon cycle since root derived aliphatic carbon has a longer residence time than the aboveground tissue-derived carbon in soils.

Soil organic matter dynamics under different land use in grasslands in Inner Mongolia (northern China)

NASA Astrophysics Data System (ADS)

Zhao, L.; Wu, W.; Xu, X.; Xu, Y.

2014-09-01

We examined bulk soil properties and molecular biomarker distributions in surface soils from Inner Mongolian grasslands in order to understand the responses of soil organic matter to different land use. A total of 16 soils were collected from severely degraded grassland by overgrazing (DG), native grassland without apparent anthropogenic disturbance (NG), groundwater-sustaining grassland (GG) and restored grassland from previous potato cropland (RG). Compared to NG, soil organic carbon content was lower by 50% in DG, but higher by six-fold in GG and one-fold in RG. The δ13C values of soil organic carbon were -24.2 ± 0.6‰ in DG, -24.9 ± 0.6‰ in NG, -25.1 ± 0.1‰ in RG and -26.2 ± 0.6‰ in GG, reflecting different degradation degrees of soil organic matter or different water use efficiencies. The soils in DG contained the lowest abundance of aliphatic lipids (n-alkanes, n-alkanols, n-alkanoic acids, ω-hydroxylalkanoic acids and α-hydroxyalkanoic acids) and lignin-phenols, suggesting selective removal of these biochemically recalcitrant biomarkers with grassland degradation by microbial respiration or wind erosion. Compared to NG, the soils in GG and RG increased ω-hydroxylalkanoic acids by 60-70%, a biomarker for suberin from roots, and increased α-hydroxylalkanoic acids by 10-20%, a biomarker for both cutin and suberin. Our results demonstrate that the groundwater supply and cultivation-restoration practices in Inner Mongolian grasslands not only enhance soil organic carbon sequestration, but also change the proportions of shoot- versus root-derived carbon in soils. This finding has important implications for the global carbon cycle since root-derived aliphatic carbon has a longer residence time than the aboveground tissue-derived carbon in soils.

No fear, just relax and play: social anxiety, alcohol expectancies, and drinking games among college students.

PubMed

Ham, Lindsay S; Zamboanga, Byron L; Olthuis, Janine V; Casner, Hilary G; Bui, Ngoc

2010-01-01

The authors examined the association between social anxiety and drinking game (DG) involvement as well as the moderating role of social anxiety-relevant alcohol outcome expectancies (AOE) in social anxiety and DG involvement among college students. Participants were 715 students (74.8% women, Mage = 19.46, SD = 1.22) from 8 US colleges. Data were collected via self-report survey from Fall 2005 to Spring 2007. Tension Reduction and Liquid Courage AOE moderated the association between social anxiety and DG participation. Tension Reduction AOE and DG participation were positively related among those with high social anxiety, but were associated negatively for those with low social anxiety. Liquid Courage AOE were associated with increased DG participation for those with low social anxiety, but not for those with high social anxiety. Findings suggest that social anxiety acts as a protective or a risk factor for DG participation among college students, depending upon AOE.

2-deoxy-D-glucose-induced metabolic stress enhances resistance to Listeria monocytogenes infection in mice

NASA Technical Reports Server (NTRS)

Miller, E. S.; Bates, R. A.; Koebel, D. A.; Fuchs, B. B.; Sonnenfeld, G.

1998-01-01

Exposure to different forms of psychological and physiological stress can elicit a host stress response, which alters normal parameters of neuroendocrine homeostasis. The present study evaluated the influence of the metabolic stressor 2-deoxy-D-glucose (2-DG; a glucose analog, which when administered to rodents, induces acute periods of metabolic stress) on the capacity of mice to resist infection with the facultative intracellular bacterial pathogen Listeria monocytogenes. Female BDF1 mice were injected with 2-DG (500 mg/kg b. wt.) once every 48 h prior to, concurrent with, or after the onset of a sublethal dose of virulent L. monocytogenes. Kinetics of bacterial growth in mice were not altered if 2-DG was applied concurrently or after the start of the infection. In contrast, mice exposed to 2-DG prior to infection demonstrated an enhanced resistance to the listeria challenge. The enhanced bacterial clearance in vivo could not be explained by 2-DG exerting a toxic effect on the listeria, based on the results of two experiments. First, 2-DG did not inhibit listeria replication in trypticase soy broth. Second, replication of L. monocytogenes was not inhibited in bone marrow-derived macrophage cultures exposed to 2-DG. Production of neopterin and lysozyme, indicators of macrophage activation, were enhanced following exposure to 2-DG, which correlated with the increased resistance to L. monocytogenes. These results support the contention that the host response to 2-DG-induced metabolic stress can influence the capacity of the immune system to resist infection by certain classes of microbial pathogens.

Drinking game participation and outcomes in a sample of Australian university students.

PubMed

George, Amanda M; Zamboanga, Byron L

2018-05-15

Most drinking game (DG) research among university students has been conducted among USA college samples. The extent to which demographics and game type (e.g. team and sculling games) are linked to DG behaviours/consequences among non-USA students is not well understood. As such, the current study investigated characteristics of DG participation (and associated outcomes) among a sample of Australian university students. University students (N = 252; aged 18-24 years; 67% female) who had consumed alcohol in the prior year completed an online survey. Measures included demographics, DG behaviours (lifetime, frequency and consumption) and gaming-specific consequences. Most of the students reported lifetime DG participation (85%). Among those who played a DG in the prior 6 months (69%), most had experienced a negative gaming-specific consequence. While team games were the most popular DG played, regression analysis demonstrated that participation in games which encouraged consumption (e.g. sculling) were associated with increased alcohol consumption during play. In addition to being older, playing DGs more frequently, and consuming more alcohol while playing, participation in both consumption and dice games (e.g. 7-11, doubles) predicted more negative gaming-specific consequences. DG participation is common among Australian university students, as it is in other parts of the world. The importance of game type is clear, particularly the risk of consumption games. Findings could help inform interventions to reduce participation in consumption games and identify students who might be especially at-risk for experiencing negative DG consequences. © 2018 Australasian Professional Society on Alcohol and other Drugs.

Evidence for a role of dystroglycan regulating the membrane architecture of astroglial endfeet

PubMed Central

Noell, Susan; Wolburg-Buchholz, Karen; Mack, Andreas F; Beedle, Aaron M; Satz, Jakob S; Campbell, Kevin P; Wolburg, Hartwig; Fallier-Becker, Petra

2011-01-01

The dystrophin–dystroglycan complex (DDC) is a molecular array of proteins in muscle and brain cells. The central component of the DDC is dystroglycan, which comprises α- and β-subunits. α-Dystroglycan (α-DG) binds to extracellular matrix components such as agrin, whereas β-dystroglycan (β-DG) is a membrane-spanning protein linking α-DG to the cytoskeleton and other intracellular components such as α-syntrophin. In astrocytes, α-syntrophin binds to the water channel protein aquaporin-4 (AQP4). Recently, it has been shown that AQP4 expression is unaltered in agrin-knockout mice, but that formation of orthogonal arrays of particles (OAPs), consisting of AQP4, is abnormal. As the brain-selective deletion of the DG gene causes a disorganization of the astroglial endfeet, we investigated whether DG deletion has an impact on AQP4. Western blotting revealed reduced AQP4 in the parenchymal but not in the superficial compartment of the astrocyte-conditioned DG-knockout mouse brain. Accordingly, immunohistochemical stainings of AQP4 revealed a selective loss of AQP4 in perivascular but not in superficial astroglial endfeet. In both superficial and perivascular endfeet of the DG-knockout brain, we observed a loss of OAPs. We conclude that in the absence of DG the majority of superficial AQP4 molecules did not form OAPs, and that expression of AQP4 in perivascular endfeet is compromised. However, the decreased number of perivascular AQP4 molecules obviously did form a few OAPs, even in the absence of DG. PMID:21501259

A global RNA-seq-driven analysis of CHO host and production cell lines reveals distinct differential expression patterns of genes contributing to recombinant antibody glycosylation.

PubMed

Könitzer, Jennifer D; Müller, Markus M; Leparc, Germán; Pauers, Martin; Bechmann, Jan; Schulz, Patrick; Schaub, Jochen; Enenkel, Barbara; Hildebrandt, Tobias; Hampel, Martin; Tolstrup, Anne B

2015-09-01

Boehringer Ingelheim uses two CHO-DG44 lines for manufacturing biotherapeutics, BI-HEX-1 and BI-HEX-2, which produce distinct cell type-specific antibody glycosylation patterns. A recently established CHO-K1 descended host, BI-HEX-K1, generates antibodies with glycosylation profiles differing from CHO-DG44. Manufacturing process development is significantly influenced by these unique profiles. To investigate the underlying glycosylation related gene expression, we leveraged our CHO host and production cell RNA-seqtranscriptomics and product quality database together with the CHO-K1 genome. We observed that each BI-HEX host and antibody producing cell line has a unique gene expression fingerprint. CHO-DG44 cells only transcribe Fut10, Gfpt2 and ST8Sia6 when expressing antibodies. BI-HEX-K1 cells express ST8Sia6 at host cell level. We detected a link between BI-HEX-1/BI-HEX-2 antibody galactosylation and mannosylation and the gene expression of the B4galt gene family and genes controlling mannose processing. Furthermore, we found major differences between the CHO-DG44 and CHO-K1 lineages in the expression of sialyl transferases and enzymes synthesizing sialic acid precursors, providing a rationale for the lack of immunogenic NeuGc/NGNA synthesis in CHO. Our study highlights the value of systems biotechnology to understand glycoprotein synthesis and product glycoprofiles. Such data improve future production clone selection and process development strategies for better steering of biotherapeutic product quality. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Permanent Whisker Removal Reduces the Density of c-Fos+ Cells and the Expression of Calbindin Protein, Disrupts Hippocampal Neurogenesis and Affects Spatial-Memory-Related Tasks.

PubMed

Gonzalez-Perez, Oscar; López-Virgen, Verónica; Ibarra-Castaneda, Nereida

2018-01-01

Facial vibrissae, commonly known as whiskers, are the main sensitive tactile system in rodents. Whisker stimulation triggers neuronal activity that promotes neural plasticity in the barrel cortex (BC) and helps create spatial maps in the adult hippocampus. Moreover, activity-dependent inputs and calcium homeostasis modulate adult neurogenesis. Therefore, the neuronal activity of the BC possibly regulates hippocampal functions and neurogenesis. To assess whether tactile information from facial whiskers may modulate hippocampal functions and neurogenesis, we permanently eliminated whiskers in CD1 male mice and analyzed the effects in cellular composition, molecular expression and memory processing in the adult hippocampus. Our data indicated that the permanent deprivation of whiskers reduced in 4-fold the density of c-Fos+ cells (a calcium-dependent immediate early gene) in cornu ammonis subfields (CA1, CA2 and CA3) and 4.5-fold the dentate gyrus (DG). A significant reduction in the expression of calcium-binding proteincalbindin-D 28k was also observed in granule cells of the DG. Notably, these changes coincided with an increase in apoptosis and a decrease in the proliferation of neural precursor cells in the DG, which ultimately reduced the number of Bromodeoxyuridine (BrdU)+NeuN+ mature neurons generated after whisker elimination. These abnormalities in the hippocampus were associated with a significant impairment of spatial memory and navigation skills. This is the first evidence indicating that tactile inputs from vibrissal follicles strongly modify the expression of c-Fos and calbindin in the DG, disrupt different aspects of hippocampal neurogenesis, and support the notion that spatial memory and navigation skills strongly require tactile information in the hippocampus.

Different Effects of Oral Contraceptive and Dydrogesterone Treatment on Oxidative Stress Levels in Premenopausal Women.

PubMed

Chen, Jui-Tung; Kotani, Kazuhiko

2018-02-01

The aim of the study was to observe the changes in blood oxidative stress levels by oral contraceptive (OC) and/or dydrogesterone (DG) treatment. A retrospective cohort of 27 premenopausal women with primary dysmenorrhea consisted of the OC treatment group (N = 17) and the DG treatment group (N = 10) by choice of the initial treatment. The OC group included two subgroups: patients with continuous OC treatment (treated for at least 15 months, N = 10) and patients with discontinuous OC treatment (switched to DG treatment after approximately 6 months of initial OC treatment: N = 7). The DG group had 15 months of continuous DG treatment. Blood parameters, including diacron-reactive oxygen metabolites (d-ROMs: an oxidative stress marker), were measured. The d-ROMs level was elevated in the OC group 3 months after initial treatment (mean: from 321 (at baseline) to 512 Carratelli Units (Carr U); P < 0.01), while such changes were not observed in the DG group. The d-ROMs level was reduced in the discontinuous OC subgroup 15 months after initial treatment (from 508 (3 months after initial treatment) to 372 Carr U; P < 0.01), while such changes were not observed in the continuous OC subgroup. The DG group displayed unchanged the d-ROMs level. Replacing OC with DG can attenuate oxidative stress as elevated by OC, thereby alleviating the possible vascular risks with OC treatment.

[Effect of 5-HT1A receptors in the hippocampal DG on active avoidance learning in rats].

PubMed

Jiang, Feng-ze; Lv, Jing; Wang, Dan; Jiang, Hai-ying; Li, Ying-shun; Jin, Qing-hua

2015-01-01

To investigate the effects of serotonin (5-HTIA) receptors in the hippocampal dentate gyrus (DG) on active avoidance learning in rats. Totally 36 SD rats were randomly divided into control group, antagonist group and agonist group(n = 12). Active avoidance learning ability of rats was assessed by the shuttle box. The extracellular concentrations of 5-HT in the DG during active avoidance conditioned reflex were measured by microdialysis and high performance liquid chromatography (HPLC) techniques. Then the antagonist (WAY-100635) or agonist (8-OH-DPAT) of the 5-HT1A receptors were microinjected into the DG region, and the active avoidance learning was measured. (1) During the active avoidance learning, the concentration of 5-HT in the hippocampal DG was significantly increased in the extinction but not establishment in the conditioned reflex, which reached 164.90% ± 26.07% (P <0.05) of basal level. (2) The microinjection of WAY-100635 (an antagonist of 5-HT1A receptor) into the DG did not significantly affect the active avoidance learning. (3) The microinjection of 8-OH-DPAT(an agonist of 5-HT1A receptor) into the DG significantly facilitated the establishment process and inhibited the extinction process during active avoidance conditioned reflex. The data suggest that activation of 5-HT1A receptors in hipocampal DG may facilitate active avoidance learning and memory in rats.

Testosterone enhances C-14 2-deoxyglucose uptake by striated muscle. [sex hormones and muscle

NASA Technical Reports Server (NTRS)

Toop, J.; Max, S. R.

1982-01-01

The effect of testosterone propionate (TP) on C-14 2-deoxyglucose (C-14 2DG) uptake was studied in the rat levator ani muscle in vivo using the autoradiographic technique. Following a delay of 1 to 3 h after injecting TP, the rate of C-14 2DG uptake in experimental animals began to increase and continued to increase for at least 20 h. The label, which corresponds to C-14 2-deoxyglucose 6-phosphate, as demonstrated by chromatographic analysis of muscle extracts, was uniformly distributed over the entire muscle and was predominantly in muscle fibers, although nonmuscular elements were also labeled. The 1 to 3 h time lag suggests that the TP effect may be genomic, acting via androgen receptors, rather than directly on muscle membranes. Acceleration of glucose uptake may be an important early event in the anabolic response of the rat levator ani muscle to androgens.

Different Forms of Vanadate on Sugar Transport in Insulin Target and Nontarget Cells

PubMed Central

2002-01-01

The effects of several vanadates (ie, orthovanadate, pervanadate, and two stable peroxovanadium compounds) on basal and insulin-stimulated 2-DG transport in insulin target and nontarget cell lines are reported, herein. In nontarget cells, exposure to vanadates (5 × 10−6 to 10−4 mol/L) resulted in 2-DG transport stimulatory responses similar to those observed in 2-DG transport post exposure to 667 nmol/L insulin alone, or insulin in combination with vanadates. In 3T3-L1 adipocytes and L6 myotubes, exposure to a vanadate compound or 67 nmol/L insulin, stimulated 2-DG transport dramatically. Again, this effect on stimulated transport was similar to 2-DG transport post-treatment with the effective vanadates in combination with insulin. While pervanadate or stable peroxovanadates stimulated 2-DG transport at 10−5 to 10−6 mol/L, orthovanadate up to 10−4 mol/L was not effective in stimulating 2-DG transport in any of the cell lines tested. The data indicate that the various peroxovanadates are clearly superior insulin mimetics while a more limited insulin mimesis is observed with orthovanadate over a wide variety of cell types. PMID:12488596

Different Forms of Vanadate on Sugar Transport in Insulin Target and Nontarget Cells.

PubMed

Germinario, Ralph J.; Colby-Germinario, Susan P.; Posner, Barry I.; Nahm, K.

2002-01-01

The effects of several vanadates (ie, orthovanadate, pervanadate, and two stable peroxovanadium compounds) on basal and insulin-stimulated 2-DG transport in insulin target and nontarget cell lines are reported, herein. In nontarget cells, exposure to vanadates (5 x 10(-6) to 10(-4) mol/L) resulted in 2-DG transport stimulatory responses similar to those observed in 2-DG transport post exposure to 667 nmol/L insulin alone, or insulin in combination with vanadates. In 3T3-L1 adipocytes and L6 myotubes, exposure to a vanadate compound or 67 nmol/L insulin, stimulated 2-DG transport dramatically. Again, this effect on stimulated transport was similar to 2-DG transport post-treatment with the effective vanadates in combination with insulin. While pervanadate or stable peroxovanadates stimulated 2-DG transport at 10(-5) to 10(-6) mol/L, orthovanadate up to 10(-4) mol/L was not effective in stimulating 2-DG transport in any of the cell lines tested. The data indicate that the various peroxovanadates are clearly superior insulin mimetics while a more limited insulin mimesis is observed with orthovanadate over a wide variety of cell types.

Energy Efficient Community Development in California: Chula Vista Research Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gas Technology Institute

2009-03-31

In 2007, the U.S. Department of Energy joined the California Energy Commission in funding a project to begin to examine the technical, economic and institutional (policy and regulatory) aspects of energy-efficient community development. That research project was known as the Chula Vista Research Project for the host California community that co-sponsored the initiative. The researches proved that the strategic integration of the selected and economically viable buildings energy efficiency (EE) measures, photovoltaics (PV), distributed generation (DG), and district cooling can produce significant reductions in aggregate energy consumption, peak demand and emissions, compared to the developer/builder's proposed baseline approach. However, themore » central power plant emission reductions achieved through use of the EE-DG option would increase local air emissions. The electric and natural gas utility infrastructure impacts associated with the use of the EE and EE-PV options were deemed relatively insignificant while use of the EE-DG option would result in a significant reduction of necessary electric distribution facilities to serve a large-scale development project. The results of the Chula Vista project are detailed in three separate documents: (1) Energy-Efficient Community Development in California; Chula Vista Research Project report contains a detailed description of the research effort and findings. This includes the methodologies, and tools used and the analysis of the efficiency, economic and emissions impacts of alternative energy technology and community design options for two development sites. Research topics covered included: (a) Energy supply, demand, and control technologies and related strategies for structures; (b) Application of locally available renewable energy resources including solar thermal and PV technology and on-site power generation with heat recovery; (c) Integration of local energy resources into district energy systems and existing energy utility networks; (d) Alternative land-use design and development options and their impact on energy efficiency and urban runoff, emissions and the heat island effect; and (e) Alternative transportation and mobility options and their impact on local emissions. (2) Creating Energy-Efficient Communities in California: A Reference Guide to Barriers, Solutions and Resources report provides the results of an effort to identify the most innovative existing and emerging public policy, incentive and market mechanisms that encourage investment in advanced energy technologies and enabling community design options in the State of California and the nation. The report evaluates each of these mechanisms in light of the preceding research and concludes with a set of recommended mechanisms designed for consideration by relevant California State agencies, development and finance industry associations, and municipal governments. (3) Creating Energy-Efficient Communities in California: A Technical Reference Guide to Building and Site Design report contains a set of selected commercially viable energy technology and community design options for high-efficiency, low-impact community development in California. It includes a summary of the research findings referenced above and recommendations for energy technology applications and energy-efficient development strategies for residential, commercial and institutional structures and supporting municipal infrastructure for planned communities. The document also identifies design options, technology applications and development strategies that are applicable to urban infill projects.« less

Distribution and identification of airborne fungi in railway stations in Tokyo, Japan.

PubMed

Kawasaki, Tamami; Kyotani, Takashi; Ushiogi, Tomoyoshi; Izumi, Yasuhiko; Lee, Hunjun; Hayakawa, Toshio

2010-01-01

The current study was performed to (1) understand the distribution of airborne fungi culturable on dichloran-glycerol agar (DG18) media over a one-year monitoring period, (2) identify the types of airborne fungi collected, and (3) compare and contrast under- and above-ground spaces, in two railway stations in Tokyo, Japan. Measurements of airborne fungi were taken at stations A and B located in Tokyo. Station A had under- and above-ground concourses and platforms whereas station B had spaces only above-ground. Airborne fungi at each measurement position were collected with an air sampler on DG18 media. After cultivation of the sample plates, the number of fungi colonies was counted on each agar plate. In station A, the underground platform was characterized as (1) having the highest humidity and (2) a high concentration of airborne fungi, with (3) a high proportion of non-sporulating fungi (NSF) and Aspergillus versicolor. There was a strong positive correlation between the concentrations of airborne particles and fungi in station A. Common aspects of the two stations were (1) that fungi were mostly detected in autumn, and (2) there was no correlation between the humidity and concentration of fungi throughout the year. The results of this study indicate that the distribution and composition of fungi differ depending on the structure of the station.

Fructo-oligosaccharide attenuates the production of pro-inflammatory cytokines and the activation of JNK/Jun pathway in the lungs of D-galactose-treated Balb/cJ mice.

PubMed

Yeh, Shu-Lan; Wu, Tzu-Chin; Chan, Shu-Ting; Hong, Meng-Jun; Chen, Hsiao-Ling

2014-01-01

This study determined the effects of long-term D-galactose (DG) injection on the lung pro-inflammatory and fibrotic status and whether fructo-oligosaccharide (FO) could attenuate such effects. Forty Balb/cJ mice (12 weeks of age) were divided into four groups: control (s.c. saline) (basal diet), DG (s.c. 1.2 g DG/kg body weight) (basal diet), DG + FO (FO diet, 2.5% w/w FO), and DG + E (vitamin E diet, α-tocopherol 0.2% w/w) serving as an antioxidant control group. These animals were killed after 49 day of treatments. Another group of naturally aging (NA) mice without any injection was killed at 64 weeks of age to be an aging control group. D-galactose treatment, generally similar to NA, increased the lung pro-inflammatory status, as shown in the IL-6 and IL-1β levels and the expression of phospho-Jun and phospho-JNK, and the fibrotic status as shown in the hydroxyproline level compared to the vehicle. FO diminished the DG-induced increases in the lung IL-1β level and expressions of total Jun, phospho-JNK, and attenuated DG effects on lung IL-6 and hydroxyproline, while α-tocopherol exerted anti-inflammatory effects on all parameters determined. FO, as well as α-tocopherol, modulated the large bowel ecology by increasing the fecal bifidobacteria and cecal butyrate levels compared with DG. D-galactose treatment mimicked the lung pro-inflammatory status as shown in the NA mice. FO attenuated the DG-induced lung pro-inflammatory status and down-regulated JNK/Jun pathway in the lung, which could be mediated by the prebiotic effects and metabolic products of FO in the large intestine.

Fructo-oligosaccharide systemically diminished D-galactose-induced oxidative molecule damages in BALB/cJ mice.

PubMed

Hsia, Chien-Hsun; Wang, Cheng-Hsin; Kuo, Yi-Wen; Ho, Ying-Jui; Chen, Hsiao-Ling

2012-06-01

Subcutaneous (s.c.) D-galactose (DG) treatment has been shown to facilitate the development of biomarkers for Alzheimer's disease in C57BL/6J mice. The aim of the present study was to determine whether this treatment in young BALB/cJ mice, another mouse strain, enhanced oxidative stress to similar extents shown in older mice, and to further determine the effects of fructo-oligosaccharide (FO), a prebiotic fibre and vitamin E (antioxidant control) on the DG-induced oxidative damage of lipids, proteins and mitochondrial DNA, and erythrocyte antioxidant enzyme activities. Mice (12 weeks of age, n 40) were divided into four groups: vehicle (s.c. saline)+control (modified rodent chow); DG (s.c. 1·2 g/kg body weight)+control; DG+FO (5 %, w/w); DG+vitamin E (α-tocopherol, 0·2 %). Then, the animals were killed after 52 d of treatment. Another natural ageing (NA) group without any injection was killed at 47 weeks of age, which served as an aged control. The results indicated that the DG treatment enhanced malonaldehyde dimethyl acetal (MDA) levels in the plasma, liver and cerebral cortex, and protein carbonyl levels in the liver and hippocampus to similar levels shown in the NA group. FO, similar to α-tocopherol, systemically normalised DG-induced elevations in the levels of MDA in the plasma, liver and cerebral cortex, protein carbonyls in the liver and hippocampus, hepatic mitochondrial 8-oxo-deoxyguanosine and erythrocyte superoxide dismutase activity. In conclusion, the s.c. DG treatment in younger BALB/cJ mice resembled the oxidative status in older mice. FO supplementation systemically prevented DG-induced oxidative stress, probably through its fermentation products and prebiotic effect.

Homologs of the Xenopus developmental gene DG42 are present in zebrafish and mouse and are involved in the synthesis of Nod-like chitin oligosaccharides during early embryogenesis.

PubMed

Semino, C E; Specht, C A; Raimondi, A; Robbins, P W

1996-05-14

The Xenopus developmental gene DG42 is expressed during early embryonic development, between the midblastula and neurulation stages. The deduced protein sequence of Xenopus DG42 shows similarity to Rhizobium Nod C, Streptococcus Has A, and fungal chitin synthases. Previously, we found that the DG42 protein made in an in vitro transcription/translation system catalyzed synthesis of an array of chitin oligosaccharides. Here we show that cell extracts from early Xenopus and zebrafish embryos also synthesize chitooligosaccharides. cDNA fragments homologous to DG42 from zebrafish and mouse were also cloned and sequenced. Expression of these homologs was similar to that described for Xenopus based on Northern and Western blot analysis. The Xenopus anti-DG42 antibody recognized a 63-kDa protein in extracts from zebrafish embryos that followed a similar developmental expression pattern to that previously described for Xenopus. The chitin oligosaccharide synthase activity found in extracts was inactivated by a specific DG42 antibody; synthesis of hyaluronic acid (HA) was not affected under the conditions tested. Other experiments demonstrate that expression of DG42 under plasmid control in mouse 3T3 cells gives rise to chitooligosaccharide synthase activity without an increase in HA synthase level. A possible relationship between our results and those of other investigators, which show stimulation of HA synthesis by DG42 in mammalian cell culture systems, is provided by structural analyses to be published elsewhere that suggest that chitin oligosaccharides are present at the reducing ends of HA chains. Since in at least one vertebrate system hyaluronic acid formation can be inhibited by a pure chitinase, it seems possible that chitin oligosaccharides serve as primers for hyaluronic acid synthesis.

Dystroglycan and muscular dystrophies related to the dystrophin-glycoprotein complex.

PubMed

Sciandra, Francesca; Bozzi, Manuela; Bianchi, Marzia; Pavoni, Ernesto; Giardina, Bruno; Brancaccio, Andrea

2003-01-01

Dystroglycan (DG) is an adhesion molecule composed of two subunits, alpha and beta, that are produced by the post-translational cleavage of a single precursor molecule. DG is a pivotal component of the dystrophin-glycoprotein complex (DGC), which connects the extracellular matrix to the cytoskeleton in skeletal muscle and many other tissues. Some muscular dystrophies are caused by mutations of DGC components, such as dystrophin, sarcoglycan or laminin-2, or also of DGC-associated molecules, such as caveolin-3. DG-null mice died during early embriogenesis and no neuromuscular diseases directly associated to genetic abnormalities of DG were identified so far. However, DG plays a crucial role for muscle integrity since its targeting at the sarcolemma is often perturbed in DGC-related neuromuscular disorders.

NR2B-dependent plasticity of adult-born granule cells is necessary for context discrimination.

PubMed

Kheirbek, Mazen A; Tannenholz, Lindsay; Hen, René

2012-06-20

Adult-generated granule cells (GCs) in the dentate gyrus (DG) exhibit a period of heightened plasticity 4-6 weeks postmitosis. However, the functional contribution of this critical window of plasticity to hippocampal neurogenesis and behavior remains unknown. Here, we show that deletion of NR2B-containing NMDA receptors from adult-born GCs impairs a neurogenesis-dependent form of LTP in the DG and reduces dendritic complexity of adult-born GCs, but does not impact their survival. Mice in which the NR2B-containing NMDA receptor was deleted from adult-born GCs did not differ from controls in baseline anxiety-like behavior or discrimination of very different contexts, but were impaired in discrimination of highly similar contexts. These results indicate that NR2B-dependent plasticity of adult-born GCs is necessary for fine contextual discrimination and is consistent with their proposed role in pattern separation.

77 FR 8751 - Guidance for Decommissioning Planning During Operations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-15

..., 40, 50, 70, and 72 [NRC-2011-0286] Guidance for Decommissioning Planning During Operations AGENCY... Guide, DG-4014, ``Decommissioning Planning During Operations'' in the Federal Register with a public... Guide DG-4014, ``Decommissioning Planning During Operations.'' This DG refers to NUREG-1757 Volume 3...

alpha-Dystroglycan does not play a major pathogenic role in autosomal recessive hereditary inclusion-body myopathy.

PubMed

Broccolini, Aldobrando; Gliubizzi, Carla; Pavoni, Ernesto; Gidaro, Teresa; Morosetti, Roberta; Sciandra, Francesca; Giardina, Bruno; Tonali, Pietro; Ricci, Enzo; Brancaccio, Andrea; Mirabella, Massimiliano

2005-02-01

Mutations of the GNE gene are responsible for autosomal recessive hereditary inclusion-body myopathy (HIBM). In this study we searched for the presence of any significant abnormality of alpha-dystroglycan (alpha-DG), a highly glycosylated component of the dystrophin-glycoprotein complex, in 5 HIBM patients which were previously clinically and genetically characterized. Immunocytochemical and immunoblot analysis showed that alpha-DG extracted from muscle biopsies was normally expressed and displayed its typical molecular mass. Immunoblot analysis on the wheat germ lectin-enriched glycoprotein fraction of muscles and primary myotubes showed a reduced amount of alpha-DG in 4 out of 5 HIBM patients, compared to normal and other diseased muscles. However, such altered lectin-binding behaviour, possibly reflecting a partial hyposialylation of alpha-DG, did not affect the laminin binding properties of alpha-DG. Therefore, the subtle changes within the alpha-DG glycosylation pattern, detected in HIBM muscles, likely do not play a key pathogenic role in this disorder.

Relaxin-3 inputs target hippocampal interneurons and deletion of hilar relaxin-3 receptors in "floxed-RXFP3" mice impairs spatial memory.

PubMed

Haidar, M; Guèvremont, G; Zhang, C; Bathgate, R A D; Timofeeva, E; Smith, C M; Gundlach, A L

2017-05-01

Hippocampus is innervated by γ-aminobutyric acid (GABA) "projection" neurons of the nucleus incertus (NI), including a population expressing the neuropeptide, relaxin-3 (RLN3). In studies aimed at gaining an understanding of the role of RLN3 signaling in hippocampus via its G i/o -protein-coupled receptor, RXFP3, we examined the distribution of RLN3-immunoreactive nerve fibres and RXFP3 mRNA-positive neurons in relation to hippocampal GABA neuron populations. RLN3-positive elements were detected in close-apposition with a substantial population of somatostatin (SST)- and GABA-immunoreactive neurons, and a smaller population of parvalbumin- and calretinin-immunoreactive neurons in different hippocampal areas, consistent with the relative distribution patterns of RXFP3 mRNA and these marker transcripts. In light of the functional importance of the dentate gyrus (DG) hilus in learning and memory, and our anatomical data, we examined the possible influence of RLN3/RXFP3 signaling in this region on spatial memory. Using viral-based Cre/LoxP recombination methods and adult mice with a floxed Rxfp3 gene, we deleted Rxfp3 from DG hilar neurons and assessed spatial memory performance and affective behaviors. Following infusions of an AAV (1/2) -Cre-IRES-eGFP vector, Cre expression was observed in DG hilar neurons, including SST-positive cells, and in situ hybridization histochemistry for RXFP3 mRNA confirmed receptor depletion relative to levels in floxed-RXFP3 mice infused with an AAV (1/2) -eGFP (control) vector. RXFP3 depletion within the DG hilus impaired spatial reference memory in an appetitive T-maze task reflected by a reduced percentage of correct choices and increased time to meet criteria, relative to control. In a continuous spontaneous alternation Y-maze task, RXFP3-depleted mice made fewer alternations in the first minute, suggesting impairment of spatial working memory. However, RXFP3-depleted and control mice displayed similar locomotor activity, anxiety-like behavior in light/dark box and elevated-plus maze tests, and learning and long-term memory retention in the Morris water maze. These data indicate endogenous RLN3/RXFP3 signaling can modulate hippocampal-dependent spatial reference and working memory via effects on SST interneurons, and further our knowledge of hippocampal cognitive processing. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

INVESTIGATING PLANET FORMATION IN CIRCUMSTELLAR DISKS: CARMA OBSERVATIONS OF RY Tau AND DG Tau

DOE Office of Scientific and Technical Information (OSTI.GOV)

Isella, Andrea; Carpenter, John M.; Sargent, Anneila I., E-mail: isella@astro.caltech.ed

2010-05-10

We present CARMA observations of the thermal dust emission from the circumstellar disks around the young stars RY Tau and DG Tau at wavelengths of 1.3 mm and 2.8 mm. The angular resolution of the maps is as high as 0.''15, or 20 AU at the distance of the Taurus cloud, which is a factor of 2 higher than has been achieved to date at these wavelengths. The unprecedented detail of the resulting disk images enables us to address three important questions related to the formation of planets. (1) What is the radial distribution of the circumstellar dust? (2) Doesmore » the dust emission show any indication of gaps that might signify the presence of (proto-)planets? (3) Do the dust properties depend on the orbital radius? We find that modeling the disk surface density in terms of either a classical power law or the similarity solution for viscous disk evolution reproduces the observations well. Both models constrain the surface density between 15 and 50 AU to within 30% for a given dust opacity. Outside this range, the densities inferred from the two models differ by almost an order of magnitude. The 1.3 mm image from RY Tau shows two peaks separated by 0.''2 with a decline in the dust emission toward the stellar position, which is significant at about 2{sigma}-4{sigma}. For both RY Tau and DG Tau, the dust emission at radii larger than 15 AU displays no significant deviation from an unperturbed viscous disk model. In particular, no radial gaps in the dust distribution are detected. Under reasonable assumptions, we exclude the presence of planets more massive than 5 M{sub J} orbiting either star at distances between about 10 and 60 AU, unless such a planet is so young that there has been insufficient time to open a gap in the disk surface density. The radial variation of the dust opacity slope, {beta}, was investigated by comparing the 1.3 mm and 2.8 mm observations. We find mean values of {beta} of 0.5 and 0.7 for DG Tau and RY Tau, respectively. Variations in {beta} are smaller than {Delta}{beta} = 0.7 between 20 and 70 AU. These results confirm that the circumstellar dust throughout these disks differs significantly from dust in the interstellar medium.« less

A GUI Based Software for Sizing Stand Alone AC Coupled Hybrid PV-Diesel Power System under Malaysia Climate

NASA Astrophysics Data System (ADS)

Syafiqah Syahirah Mohamed, Nor; Amalina Banu Mohamat Adek, Noor; Hamid, Nurul Farhana Abd

2018-03-01

This paper presents the development of Graphical User Interface (GUI) software for sizing main component in AC coupled photovoltaic (PV) hybrid power system based on Malaysia climate. This software provides guideline for PV system integrator to design effectively the size of components and system configuration to match the system and load requirement with geographical condition. The concept of the proposed software is balancing the annual average renewable energy generation and load demand. In this study, the PV to diesel generator (DG) ratio is introduced by considering the hybrid system energy contribution. The GUI software is able to size the main components in the PV hybrid system to meet with the set target of energy contribution ratio. The rated powers of the components to be defined are PV array, grid-tie inverter, bi-directional inverter, battery storage and DG. GUI is used to perform all the system sizing procedures to make it user friendly interface as a sizing tool for AC coupled PV hybrid system. The GUI will be done by using Visual Studio 2015 based on the real data under Malaysia Climate.

Comparison of Doppler-guided haemorrhoidal artery ligation without mucopexy and rubber band ligation for haemorrhoids.

PubMed

Pol, Robert A; van der Zwet, Wil C; Kaijser, Mirjam; Schattenkerk, Marinus Eeftinck; Eddes, Eric-Hans

2011-12-01

Recurrences after Doppler-guided haemorrhoidal artery ligation (DG-HAL) tend to occur in patients with concurrent mucosal prolapse. We retrospectively compared the results of DG-HAL and rubber band ligation (RBL) for the treatment of haemorrhoidal disease. From 2005 to 2009, all patients who underwent either a DG-HAL procedure or RBL were selected. Follow-up was done by telephone using a standardised questionnaire survey to assess patient satisfaction and complaints. When recurrent disease was suspected, patients revisited the clinic for further examination and treatment. A total of 239 DG-HAL patients and 47 RBL patients were analysed. Sixty-seven percent in the DG-HAL group and 79% in the RBL group had an improvement in symptoms after one treatment (p=0.22). Forty-six DG-HAL patients (19%) needed a second procedure versus three patients (6%) in the RBL group (p<0.05). Cox regression analysis showed a significant difference in disease recurrence in favour of RBL (hazard ratio (HR) 3.71, 95% confidence interval (CI) 1.13-12.2). Patients in the DG-HAL group with recurrent haemorrhoids had a higher incidence of mucosal prolapse. DG-HAL seems very effective in treating lower-grade haemorrhoids. In more advanced disease, recurrence occurs due to persisting mucosal prolapse. RBL seems much more effective in reducing the prolapse and the chance of recurrence. Copyright © 2011 Arab Journal of Gastroenterology. Published by Elsevier Ltd. All rights reserved.

Different Effects of Oral Contraceptive and Dydrogesterone Treatment on Oxidative Stress Levels in Premenopausal Women

PubMed Central

Chen, Jui-Tung; Kotani, Kazuhiko

2018-01-01

Background The aim of the study was to observe the changes in blood oxidative stress levels by oral contraceptive (OC) and/or dydrogesterone (DG) treatment. Methods A retrospective cohort of 27 premenopausal women with primary dysmenorrhea consisted of the OC treatment group (N = 17) and the DG treatment group (N = 10) by choice of the initial treatment. The OC group included two subgroups: patients with continuous OC treatment (treated for at least 15 months, N = 10) and patients with discontinuous OC treatment (switched to DG treatment after approximately 6 months of initial OC treatment: N = 7). The DG group had 15 months of continuous DG treatment. Blood parameters, including diacron-reactive oxygen metabolites (d-ROMs: an oxidative stress marker), were measured. Results The d-ROMs level was elevated in the OC group 3 months after initial treatment (mean: from 321 (at baseline) to 512 Carratelli Units (Carr U); P < 0.01), while such changes were not observed in the DG group. The d-ROMs level was reduced in the discontinuous OC subgroup 15 months after initial treatment (from 508 (3 months after initial treatment) to 372 Carr U; P < 0.01), while such changes were not observed in the continuous OC subgroup. The DG group displayed unchanged the d-ROMs level. Conclusion Replacing OC with DG can attenuate oxidative stress as elevated by OC, thereby alleviating the possible vascular risks with OC treatment. PMID:29317960

Abnormal processing of deontological guilt in obsessive-compulsive disorder.

PubMed

Basile, Barbara; Mancini, Francesco; Macaluso, Emiliano; Caltagirone, Carlo; Bozzali, Marco

2014-07-01

Guilt plays a significant role in the occurrence and maintenance of obsessive-compulsive disorder (OCD). Two major types of guilt have been identified: one deriving from the transgression of a moral rule (deontological guilt DG), another (altruistic guilt AG), relying on the assumption of having compromised a personal altruistic goal. Clinical evidence suggests that OCD patients are particularly sensitive to DG, but not AG. In this functional magnetic resonance imaging (fMRI) study, we investigated brain response of OCD patients while processing DG and AG stimuli. A previously validated fMRI paradigm was used to selectively evoke DG and AG, and anger and sadness, as control emotions in 13 OCD patients and 19 healthy controls. Patients' behavioral results showed a prominent attitude to experience guilt, compared to controls, while accomplishing task. fMRI results revealed that patients have reduced activation in the anterior cingulate (ACC) and frontal gyrus when experiencing guilt, regardless of its specific type (DG or AG). When separately considering each type of guilt (against each of its control), patients showed decreased activation in the ACC, the insula and the precuneus, for DG. No significant differences were observed between groups when processing AG, anger or sad stimuli. This study provides evidence for an abnormal processing of guilt, and specifically DG, in OCD patients. We suggest that decreased activation may reflect patients' cerebral efficiency, which derives from their frequent exposure to guilty feelings ("neural efficiency hypothesis"). In conclusion, our study confirms a selective abnormal processing of guilt, and specifically DG, in OCD.

Simulation of Ultra-Small MOSFETs Using a 2-D Quantum-Corrected Drift-Diffusion Model

NASA Technical Reports Server (NTRS)

Biegal, Bryan A.; Rafferty, Connor S.; Yu, Zhiping; Ancona, Mario G.; Dutton, Robert W.; Saini, Subhash (Technical Monitor)

1998-01-01

The continued down-scaling of electronic devices, in particular the commercially dominant MOSFET, will force a fundamental change in the process of new electronics technology development in the next five to ten years. The cost of developing new technology generations is soaring along with the price of new fabrication facilities, even as competitive pressure intensifies to bring this new technology to market faster than ever before. To reduce cost and time to market, device simulation must become a more fundamental, indeed dominant, part of the technology development cycle. In order to produce these benefits, simulation accuracy must improve markedly. At the same time, device physics will become more complex, with the rapid increase in various small-geometry and quantum effects. This work describes both an approach to device simulator development and a physical model which advance the effort to meet the tremendous electronic device simulation challenge described above. The device simulation approach is to specify the physical model at a high level to a general-purpose (but highly efficient) partial differential equation solver (in this case PROPHET, developed by Lucent Technologies), which then simulates the model in 1-D, 2-D, or 3-D for a specified device and test regime. This approach allows for the rapid investigation of a wide range of device models and effects, which is certainly essential for device simulation to catch up with, and then stay ahead of, electronic device technology of the present and future. The physical device model used in this work is the density-gradient (DG) quantum correction to the drift-diffusion model [Ancona, Phys. Rev. B 35(5), 7959 (1987)]. This model adds tunneling and quantum smoothing of carrier density profiles to the drift-diffusion model. We used the DG model in 1-D and 2-D (for the first time) to simulate both bipolar and unipolar devices. Simulations of heavily-doped, short-base diodes indicated that the DG quantum corrections do not have a large effect on the IN characteristics of electronic devices without heteroj unction s. On the other hand, ultra-small MOSFETs certainly exhibit important quantum effects that the DG model will include: quantum repulsion of the inversion and gate charges from the oxide interfaces, and quantum tunneling through thin gate oxides. We present initial results of 2-D DG simulations of ultra-small MOSFETs. Subtle but important issues involving the specification of the model, boundary conditions, and interface constraints for DG simulation of MOSFETs will also be illuminated.

Hydrophobic Amino Acids in the Human Immunodeficiency Virus Type 1 p2 and Nucleocapsid Proteins Can Contribute to the Rescue of Deleted Viral RNA Packaging Signals

PubMed Central

Rong, Liwei; Russell, Rodney S.; Hu, Jing; Guan, Yongjun; Kleiman, Lawrence; Liang, Chen; Wainberg, Mark A.

2001-01-01

An RNA fragment of 75 nucleotides, which is located between the primer binding site and the 5′ major splice donor site in human immunodeficiency virus type 1, has been shown to participate in specific encapsidation of viral RNA. Compensation studies have identified two second-site mutations, namely, MP2 (a T12I substitution in p2) and MNC (a T24I substitution in the nucleocapsid [NC] protein) that were involved in the rescue of various deletions in the aforementioned RNA region (i.e., BH-D1, BH-D2, and BH-LD3). To study whether the MP2 and MNC point mutations exert their compensatory effects in a cis manner, production of Gag proteins was blocked by insertion of stop codons into LD3, LD3-MP2-MNC, and wild-type BH10 such that the constructs generated, i.e., LD3-DG, LD3-MP2-MNC-DG, and BH-DG, only provided RNA transcripts for packaging. The results of cotransfection experiments showed that the LD3-MP2-MNC-DG viral RNA was packaged as inefficiently as LD3-DG; in contrast, BH-DG was efficiently packaged. Therefore, nucleotide substitutions in MP2 and MNC did not act in a cis manner to correct the packaging deficits in LD3. Next, we deliberately changed the T12 in p2 or the T24 in the NC to each of 19 other amino acids. We found that amino acids with long hydrophobic side chains, i.e., V, L, I, and M, were favored at either position 12 in p2 or at position 24 in NC to compensate for the above-mentioned deletions. Further studies showed that only a few amino acids could not be used at these two sites by the wild-type virus due to decreased RNA levels in the virion or abnormal Gag protein processing. In this case, W, D, and E could not substitute for T12 in p2, and S, D, and N could not substitute for T24 in NC, without affecting viral infectivity. Therefore, the long hydrophobic side chains of V, L, I, and M are necessary for these amino acids to rescue the BH-D1, BH-D2, and BH-LD3 mutated viruses. PMID:11461996

Review of droop-controlled bi-directional inverter in conducting islanded operation of photovoltaic systems

NASA Astrophysics Data System (ADS)

Khaw, Ace Lin Yi; Wong, Jianhui; Lim, Yun Seng

2017-04-01

Global warming due to the excessive greenhouse gas emissions has led to the emergence of green technologies in Malaysia, particularly photovoltaic (PV) systems. Under the current regulatory framework, islanded operation of the PV system is not permissible. As a result, any renewable energy sources will be disconnected immediately in the event of grid outages. This practice is to ensure the safety of working personnel, as well as the customer equipment connected within the distribution networks. In addition, there is no synchronizing equipment to aid the reconnection of the islanded network to the grid. However, with the shutdown of the Distributed Generator (DG) during islanded operation, the customers are not able to utilize the available renewable energy and the number of power interruption is not improved with the renewable energy sources. Therefore, the main objective of this paper is to investigate the feasibility of the PV system in conducting islanding operation with the use of Energy Storage System (ESS). This paper also proposes a control algorithm to maintain the voltage and frequency excursion within the statutory limit by manipulating the real and reactive power flow of the ESS within the transition period between grid connected and islanding operation.

Coordinated Voltage Control of Transformer Taps on account of Hierarchical Structure in Power System

NASA Astrophysics Data System (ADS)

Nakachi, Yoshiki; Kato, Satoshi; Ukai, Hiroyuki

Participation of distributed generators (DG), such as wind turbines, co-generation system etc., is natural trend from ecological point of view and will increase more and more. The outputs of these DGs mainly depend on weather condition but don't correspond to the changes of electrical load demand necessarily. On the other hand, due to the deregulation of electric power market, the power flow in power system will uncertainly vary with several power transactions. Thus, complex power flow by DGs or transactions will cause the voltage deviation. It will be difficult to sustain the voltage quality by using the conventional voltage/reactive power control in near future. In this paper, in order to avoid such a voltage deviation and to decrease the frequency of transformer tap actions, the coordinated voltage control scheme of transformer taps on account of hierarchical structure in power system is proposed. In the proposed scheme, integral of voltage deviation at each layer bus is applied to decide the timing of each transformer tap action. It is confirmed by some numerical simulations that the proposed scheme is able to respond to every conditions on voltage deviation.

Steering law for parallel mounted double-gimbaled control moment gyros

NASA Technical Reports Server (NTRS)

Kennel, H. F.

1975-01-01

Parallel mounting of double-gimbaled control moment gyros (DG CMG) is discussed in terms of simplification of the steering law. The steering law/parallel mounted DG CMG is considered to be a 'CMG kit' applicable to any space vehicle where the need for DG CMG's has been established.

77 FR 71359 - Airworthiness Directives; DG Flugzeugbau GmbH Gliders

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-30

...H Gliders AGENCY: Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION... DG Flugzeugbau GmbH Model DG-1000T gliders equipped with Solo Kleinmotoren Model 2350 C engines. This... proposed AD, contact Solo Kleinmotoren GmbH, Postfach 60 01 52, D 71050 Sindelfingen, Germany; telephone...

Localization of alpha-dystroglycan on the podocyte: from top to toe.

PubMed

Vogtländer, Nils P J; Dijkman, Henry; Bakker, Marinka A H; Campbell, Kevin P; van der Vlag, Johan; Berden, Jo H M

2005-11-01

alpha-Dystroglycan (DG) is a negatively charged membrane-associated glycoprotein that links the cytoskeleton to the extracellular matrix. Previously, we described that alpha-DG covers the whole podocyte cell membrane in the rat. However, our finding was challenged by the description of a strictly basolateral localization in human kidney biopsies, using a different antibody against alpha-DG. Therefore, we studied the exact localization of glomerular alpha-DG by using these two antibodies in both species. The studies were performed by using monoclonal antibodies (MoAbs) IIH6 and VIA4.1 in immunofluorescence, confocal microscopy, and immunoelectron microscopy on both rat and human kidney sections, as well as on cultured mouse podocytes. The apical localization of alpha-DG on podocytes was more dominant than the basolateral localization. The basolateral staining with MoAb VIA4.1 was more pronounced than that of MoAb IIH6. With both MoAbs, the staining in rat kidneys was more prominent, in comparison to human kidneys. We conclude that alpha-DG is expressed at both the basolateral and apical sides of the podocyte. This localization suggests that alpha-DG plays a dual role in the maintenance of the unique architecture of podocytes by its binding to the glomerular basement membrane, and in the maintenance of the integrity of the filtration slit, respectively.

Locus Coeruleus Stimulation Facilitates Long-Term Depression in the Dentate Gyrus That Requires Activation of β-Adrenergic Receptors

PubMed Central

Hansen, Niels; Manahan-Vaughan, Denise

2015-01-01

Synaptic plasticity comprises a cellular mechanism through which the hippocampus most likely enables memory formation. Neuromodulation, related to arousal, is a key aspect in information storage. The activation of locus coeruleus (LC) neurons by novel experience leads to noradrenaline release in the hippocampus at the level of the dentate gyrus (DG). We explored whether synaptic plasticity in the DG is influenced by activation of the LC via electrical stimulation. Coupling of test-pulses that evoked stable basal synaptic transmission in the DG with stimulation of the LC induced β-adrenoreceptor-dependent long-term depression (LTD) at perforant path–DG synapses in adult rats. Furthermore, persistent LTD (>24 h) induced by perforant path stimulation also required activation of β-adrenergic receptors: Whereas a β-adrenergic receptor antagonist (propranolol) prevented, an agonist (isoproterenol) strengthened the persistence of LTD for over 24 h. These findings support the hypothesis that persistent LTD in the DG is modulated by β-adrenergic receptors. Furthermore, LC activation potently facilitates DG LTD. This suggests in turn that synaptic plasticity in the DG is tightly regulated by activity in the noradrenergic system. This may reflect the role of the LC in selecting salient information for subsequent synaptic processing in the hippocampus. PMID:24464942

AuNP-DG: deoxyglucose-labeled gold nanoparticles as X-ray computed tomography contrast agents for cancer imaging.

PubMed

Aydogan, Bulent; Li, Ji; Rajh, Tijana; Chaudhary, Ahmed; Chmura, Steven J; Pelizzari, Charles; Wietholt, Christian; Kurtoglu, Metin; Redmond, Peter

2010-10-01

To study the feasibility of using 2-deoxy-D-glucose (2-DG)-labeled gold nanoparticle (AuNP-DG) as a computed tomography (CT) contrast agent with tumor targeting capability through in vitro experiments. Gold nanoparticles (AuNP) were fabricated and were conjugated with 2-deoxy-D-glucose. The human alveolar epithelial cancer cell line, A-549, was chosen for the in vitro cellular uptake assay. Two groups of cell samples were incubated with the AuNP-DG and the unlabeled AuNP, respectively. Following the incubation, the cells were washed with sterile PBS to remove the excess gold nanoparticles and spun to cell pellets using a centrifuge. The cell pellets were imaged using a microCT scanner immediately after the centrifugation. The reconstructed CT images were analyzed using a commercial software package. Significant contrast enhancement in the cell samples incubated with the AuNP-DG with respect to the cell samples incubated with the unlabeled AuNP was observed in multiple CT slices. Results from this study demonstrate enhanced uptake of 2-DG-labeled gold nanoparticle by cancer cells in vitro and warrant further experiments to study the exact molecular mechanism by which the AuNP-DG is internalized and retained in the tumor cells.

Structural and Functional Analysis of Sulfolobus solfataricus Y-Family DNA Polymerase Dpo4-Catalyzed Bypass of the Malondialdehyde−Deoxyguanosine Adduct

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eoff, Robert L.; Stafford, Jennifer B.; Szekely, Jozsef

2010-01-12

Oxidative stress can induce the formation of reactive electrophiles, such as DNA peroxidation products, e.g., base propenals, and lipid peroxidation products, e.g., malondialdehyde. Base propenals and malondialdehyde react with DNA to form adducts, including 3-(2'-deoxy-{beta}-d-erythro-pentofuranosyl)pyrimido[1,2-{alpha}]purin-10(3H)-one (M{sub 1}dG). When paired opposite cytosine in duplex DNA at physiological pH, M{sub 1}dG undergoes ring opening to form N{sup 2}-(3-oxo-1-propenyl)-dG (N{sup 2}-OPdG). Previous work has shown that M{sub 1}dG is mutagenic in bacteria and mammalian cells and that its mutagenicity in Escherichia coli is dependent on induction of the SOS response, indicating a role for translesion DNA polymerases in the bypass of M{sub 1}dG.more » To probe the mechanism by which translesion polymerases bypass M{sub 1}dG, kinetic and structural studies were conducted with a model Y-family DNA polymerase, Dpo4 from Sulfolobus solfataricus. The level of steady-state incorporation of dNTPs opposite M{sub 1}dG was reduced 260-2900-fold and exhibited a preference for dATP incorporation. Liquid chromatography-tandem mass spectrometry analysis of the full-length extension products revealed a spectrum of products arising principally by incorporation of dC or dA opposite M{sub 1}dG followed by partial or full-length extension. A greater proportion of -1 deletions were observed when dT was positioned 5' of M{sub 1}dG. Two crystal structures were determined, including a 'type II' frameshift deletion complex and another complex with Dpo4 bound to a dC-M{sub 1}dG pair located in the postinsertion context. Importantly, M{sub 1}dG was in the ring-closed state in both structures, and in the structure with dC opposite M{sub 1}dG, the dC residue moved out of the Dpo4 active site, into the minor groove. The results are consistent with the reported mutagenicity of M{sub 1}dG and illustrate how the lesion may affect replication events.« less

Distribution of cocaine- and amphetamine-regulated transcript in the hippocampal formation of the guinea pig and domestic pig.

PubMed

Kolenkiewicz, M; Robak, A; Równiak, M; Bogus-Nowakowska, K; Całka, J; Majewski, M

2009-02-01

This study provides a detailed description concerning the distribution of cocaineand amphetamine-regulated transcript (CART) subunits - CART(61-102) and rhCART(28-116) - in the hippocampal formation (HF) of the guinea pig and domestic pig, focussing on the dentate gyrus (DG) and hippocampus proper (HP). Although in both studied species CART-immunoreactive (CART-IR) neuronal somata and processes were present generally in the same layers, some species-specific differences were still found. In the granular layer (GL) of both species, the ovalshaped neurons and some thick varicose fibres were encountered. In the guinea pig there was an immunoreactive "band of dots", probably representing crosssectioned terminals within the DG molecular layer (MOL), whereas in the domestic pig, some varicose fibres were detected, thus suggesting a different orientation of, at least, some nerve terminals. Furthermore, some CART-positive cells and fibres were observed in the hilus (HL) of the guinea pig, whereas in the analogical part of the domestic pig only nerve terminals were labelled. In both species, in the pyramidal layer (PL) of the hippocampus proper, CART-IR triangular somata were observed in the CA3 sector, as well as some positive processes in MOL; however, a few immunoreactive perikarya were found only in the CA1 sector of the guinea pig. As regards the localization patterns of two isoforms of CART in the guinea pig, both peptide fragments were present simultaneously in each of the labelled neurons or fibres, whereas in the domestic pig three types of fibres may be distinguished within the area of the DG. In the hilus and MOL of the dentate gyrus, there were fibres expressing both isoforms of CART in their whole length (fibres of the first type). Fibres of the second type (in GL) coexpressed both peptides only on their short segments, and the last ones (in MOL) expressed solely rhCART(28-116). These results indicate that the distribution of the two CART isoforms are specifically related, thus the relationship between the two CART isoforms may imply different metabolic profiles of CART-expressing neurons.

Two Sulfur Glycoside Compounds Isolated from Lepidium apetalum Willd Protect NRK52e Cells against Hypertonic-Induced Adhesion and Inflammation by Suppressing the MAPK Signaling Pathway and RAAS.

PubMed

Yuan, Peipei; Zheng, Xiaoke; Li, Meng; Ke, Yingying; Fu, Yang; Zhang, Qi; Wang, Xiaolan; Feng, Weisheng

2017-11-12

Lepidium apetalum Willd has been used to reduce edema and promote urination. Cis -desulfoglucotropaeolin ( cis -DG) and trans -desulfoglucotropaeolin ( trans -DG) were isolated from Lepidium apetalum Willd, and caused a significant increase in cell viability in a hypertonic model in NRK52e cells. In the hypertonic model, cis -DG and trans -DG significantly promoted the cell viability of NRK52e cells and inhibited the elevation of Na⁺ in the supernatant, inhibited the renin-angiotensin-aldosterone (RAAS) system, significantly reduced the levels of angiotensin II (Ang II) and aldosterone (ALD), and lowered aquaporin-2 (AQP2) and Na⁺-K⁺ ATP content in renal medulla. After treatment with cis -DG and trans -DG, expression of calcineurin (CAN) and Ca/calmodulin-dependent protein kinase II (CaMK II) was decreased in renal tissue and Ca 2+ influx was inhibited, thereby reducing the secretion of transforming growth factor-β (TGFβ), reversing the increase in adhesion and inflammatory factor E-selectin and monocyte chemotactic protein 1 (MCP-1) induced by high NaCl, while reducing oxidative stress status and decreasing the expression of cyclooxygenase-2 (COX2). Furthermore, inhibition of protein kinase C (PKC) expression also contributed to these improvements. The cis -DG and trans -DG reduced the expression of p-p44/42 MAPK, p-JNK and p-p38, inhibited the phosphorylation of the MAPK signaling pathway in NRN52e cells induced by high salt, decreased the overexpression of p-p38 and p-HSP27, and inhibited the overactivation of the p38-MAPK signaling pathway, suggesting that the p38-MAPK pathway may play a vital role in the hypertonic-induced adhesion and inflammatory response. From the results of this study, it can be concluded that the mechanism of cis -DG and trans -DG may mainly be through inhibiting the p38-MAPK signaling pathway, inhibiting the excessive activation of the RAAS system, and thereby reducing adhesion and inflammatory factors.

Mutations in GDP-mannose pyrophosphorylase B cause congenital and limb-girdle muscular dystrophies associated with hypoglycosylation of α-dystroglycan.

PubMed

Carss, Keren J; Stevens, Elizabeth; Foley, A Reghan; Cirak, Sebahattin; Riemersma, Moniek; Torelli, Silvia; Hoischen, Alexander; Willer, Tobias; van Scherpenzeel, Monique; Moore, Steven A; Messina, Sonia; Bertini, Enrico; Bönnemann, Carsten G; Abdenur, Jose E; Grosmann, Carla M; Kesari, Akanchha; Punetha, Jaya; Quinlivan, Ros; Waddell, Leigh B; Young, Helen K; Wraige, Elizabeth; Yau, Shu; Brodd, Lina; Feng, Lucy; Sewry, Caroline; MacArthur, Daniel G; North, Kathryn N; Hoffman, Eric; Stemple, Derek L; Hurles, Matthew E; van Bokhoven, Hans; Campbell, Kevin P; Lefeber, Dirk J; Lin, Yung-Yao; Muntoni, Francesco

2013-07-11

Congenital muscular dystrophies with hypoglycosylation of α-dystroglycan (α-DG) are a heterogeneous group of disorders often associated with brain and eye defects in addition to muscular dystrophy. Causative variants in 14 genes thought to be involved in the glycosylation of α-DG have been identified thus far. Allelic mutations in these genes might also cause milder limb-girdle muscular dystrophy phenotypes. Using a combination of exome and Sanger sequencing in eight unrelated individuals, we present evidence that mutations in guanosine diphosphate mannose (GDP-mannose) pyrophosphorylase B (GMPPB) can result in muscular dystrophy variants with hypoglycosylated α-DG. GMPPB catalyzes the formation of GDP-mannose from GTP and mannose-1-phosphate. GDP-mannose is required for O-mannosylation of proteins, including α-DG, and it is the substrate of cytosolic mannosyltransferases. We found reduced α-DG glycosylation in the muscle biopsies of affected individuals and in available fibroblasts. Overexpression of wild-type GMPPB in fibroblasts from an affected individual partially restored glycosylation of α-DG. Whereas wild-type GMPPB localized to the cytoplasm, five of the identified missense mutations caused formation of aggregates in the cytoplasm or near membrane protrusions. Additionally, knockdown of the GMPPB ortholog in zebrafish caused structural muscle defects with decreased motility, eye abnormalities, and reduced glycosylation of α-DG. Together, these data indicate that GMPPB mutations are responsible for congenital and limb-girdle muscular dystrophies with hypoglycosylation of α-DG. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Morphopathological features in tissues of alpha-mannosidosis guinea pigs at different gestational ages.

PubMed

Auclair, D; Hopwood, J J

2007-10-01

Alpha-mannosidosis is an inherited metabolic disorder characterized by a reduction in alpha-D-mannosidase and intralysosomal accumulation of undegraded mannose-containing oligosaccharides. The alpha-mannosidosis guinea pig exhibits pathological similarities to its human counterpart, which make it a valuable animal model. To trace the progression of alpha-mannosidosis during foetal development, brain and visceral organs from affected and unaffected guinea pigs at 30, 36, 38, 51 and 65 days of gestation (dg) were examined by light and electron microscopy (term: approximately 68 dg). In the affected brain, distended lysosomes (vacuoles) were scarce up to 38 dg and were seen in few differentiating neuronal cells but mostly in macrophages, pericytes and endothelial cells. At 51 and 65 dg, several vacuoles were observed in some neurones, in many Purkinje cells, pericytes, endothelial and microglial cells, and in few cerebellar internal granule cells. Myelination had started by 51 dg. Non-myelinated axonal spheroids were detected in the brainstem at 65 dg. In the kidney cortex and liver, an increase in vacuolation was noticed between 36 and 65 dg. Some vacuolated cells were also noticed in the lungs and spleen at 51 and 65 dg. Altogether, these histological observations suggest that alpha-mannosidosis is unlikely to affect ontogenesis before the second half of gestation in guinea pigs; however, the morphopathological features recorded during the last quarter of gestation (which may roughly correspond to the period covering near term to 1-2 years of age in human) were clearly noticeable and may have had some impact.

An evaluation of total starch and starch gelatinization methodologies in pelleted animal feed.

PubMed

Zhu, L; Jones, C; Guo, Q; Lewis, L; Stark, C R; Alavi, S

2016-04-01

The quantification of total starch content (TS) or degree of starch gelatinization (DG) in animal feed is always challenging because of the potential interference from other ingredients. In this study, the differences in TS or DG measurement in pelleted swine feed due to variations in analytical methodology were quantified. Pelleted swine feed was used to create 6 different diets manufactured with various processing conditions in a 2 × 3 factorial design (2 conditioning temperatures, 77 or 88°C, and 3 conditioning retention times, 15, 30, or 60 s). Samples at each processing stage (cold mash, hot mash, hot pelletized feed, and final cooled pelletized feed) were collected for each of the 6 treatments and analyzed for TS and DG. Two different methodologies were evaluated for TS determination (the AOAC International method 996.11 vs. the modified glucoamylase method) and DG determination (the modified glucoamylase method vs. differential scanning calorimetry [DSC]). For TS determination, the AOAC International method 996.11 measured lower TS values in cold pellets compared with the modified glucoamylase method. The AOAC International method resulted in lower TS in cold mash than cooled pelletized feed, whereas the modified glucoamylase method showed no significant differences in TS content before or after pelleting. For DG, the modified glucoamylase method demonstrated increased DG with each processing step. Furthermore, increasing the conditioning temperature and time resulted in a greater DG when evaluated by the modified glucoamylase method. However, results demonstrated that DSC is not suitable as a quantitative tool for determining DG in multicomponent animal feeds due to interferences from nonstarch transformations, such as protein denaturation.

Synthesis and structure of duplex DNA containing the genotoxic nucleobase lesion N7-methylguanine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, S.; Bowman, B.R.; Ueno, Y.

2008-11-03

The predominant product of aberrant DNA methylation is the genotoxic lesion N7-methyl-2{prime}-deoxyguanosine (m{sup 7}dG). M{sup 7}dG is recognized and excised by lesion-specific DNA glycosylases, namely AlkA in E. coli and Aag in humans. Structural studies of m{sup 7}dG recognition and catalysis by these enzymes have been hampered due to a lack of efficient means by which to incorporate the chemically labile m{sup 7}dG moiety site-specifically into DNA on a preparative scale. Here we report a solution to this problem. We stabilized the lesion toward acid-catalyzed and glycosylase-catalyzed depurination by 2{prime}-fluorination and toward base-catalyzed degradation using mild, nonaqueous conditions in themore » DNA deprotection reaction. Duplex DNA containing 2{prime}-fluoro-m{sup 7}dG (Fm{sup 7}dG) cocrystallized with AlkA as a host-guest complex in which the lesion-containing segment of DNA was nearly devoid of protein contacts, thus enabling the first direct visualization of the N7-methylguanine lesion nucleobase in DNA. The structure reveals that the base-pairing mode of Fm{sup 7}dG:C is nearly identical to that of G:C, and Fm{sup 7}dG does not induce any apparent structural disturbance of the duplex structure. These observations suggest that AlkA and Aag must perform a structurally invasive interrogation of DNA in order to detect the presence of intrahelical m{sup 7}dG lesions.« less

2-Deoxyglucose impairs Saccharomyces cerevisiae growth by stimulating Snf1-regulated and α-arrestin-mediated trafficking of hexose transporters 1 and 3.

PubMed

O'Donnell, Allyson F; McCartney, Rhonda R; Chandrashekarappa, Dakshayini G; Zhang, Bob B; Thorner, Jeremy; Schmidt, Martin C

2015-03-01

The glucose analog 2-deoxyglucose (2DG) inhibits the growth of Saccharomyces cerevisiae and human tumor cells, but its modes of action have not been fully elucidated. Yeast cells lacking Snf1 (AMP-activated protein kinase) are hypersensitive to 2DG. Overexpression of either of two low-affinity, high-capacity glucose transporters, Hxt1 and Hxt3, suppresses the 2DG hypersensitivity of snf1Δ cells. The addition of 2DG or the loss of Snf1 reduces HXT1 and HXT3 expression levels and stimulates transporter endocytosis and degradation in the vacuole. 2DG-stimulated trafficking of Hxt1 and Hxt3 requires Rod1/Art4 and Rog3/Art7, two members of the α-arrestin trafficking adaptor family. Mutations in ROD1 and ROG3 that block binding to the ubiquitin ligase Rsp5 eliminate Rod1- and Rog3-mediated trafficking of Hxt1 and Hxt3. Genetic analysis suggests that Snf1 negatively regulates both Rod1 and Rog3, but via different mechanisms. Snf1 activated by 2DG phosphorylates Rod1 but fails to phosphorylate other known targets, such as the transcriptional repressor Mig1. We propose a novel mechanism for 2DG-induced toxicity whereby 2DG stimulates the modification of α-arrestins, which promote glucose transporter internalization and degradation, causing glucose starvation even when cells are in a glucose-rich environment. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Absence of IDH1-R132H mutation predicts rapid progression of nonenhancing diffuse glioma in older adults.

PubMed

Olar, Adriana; Raghunathan, Aditya; Albarracin, Constance T; Aldape, Kenneth D; Cahill, Daniel P; Powell, Suzanne Z; Goodman, J Clay; Fuller, Gregory N

2012-06-01

Advanced age and contrast enhancement portend a poor prognosis in diffuse glioma (DG). Diffuse glioma may present as nonenhancing tumors that rapidly progress in weeks to months to a pattern of ring enhancement, characteristic of glioblastoma (GBM). Mutations involving isocitrate dehydrogenase 1 (IDH1) have recently emerged as important diagnostic and prognostic markers in DG. R132H is the most common mutation, expressed in more than 80% of DG and secondary GBM but in less than 10% of primary GBM. Adults older than 50 years with nonenhancing, rapidly progressing DG were identified. A comparison group comprised randomly selected, age-matched patients with nonenhancing, nonprogressing DG. Isocitrate dehydrogenase 1 status was evaluated using anti-IDH1-R132H antibodies (Dianova, Hamburg, Germany). The results were correlated with the clinical outcomes. We identified 4 patients who presented with nonenhancing DG that rapidly progressed to ring-enhancing lesions that were subsequently diagnosed on surgical resection as GBM. This group showed absent IDH1-R132H expression, which is characteristic of primary GBM. The comparison group of 5 patients presented with nonenhancing, nonprogressing DG, and all 5 tumors showed IDH1-R132H expression. In conclusion, negative IDH1-R132H mutation status in nonenhancing DG of older adults is a poor prognostic factor associated with rapid progression to ring-enhancing GBM. The shorter interval of progression and negative IDH1-R132H mutation status suggest a similar molecular pathway as seen in primary GBM. Copyright © 2012 Elsevier Inc. All rights reserved.

A two-dimensional (2D) analytical subthreshold swing and transconductance model of underlap dual-material double-gate (DMDG) MOSFET for analog/RF applications

NASA Astrophysics Data System (ADS)

Narendar, Vadthiya; Rai, Saurabh; Tiwari, Siddharth; Mishra, R. A.

2016-12-01

The double-gate (DG) metal-oxide-semiconductor field effect transistors (MOSFETs) are the choice of technology in sub -100 nm regime of leading microelectronics industry. To enhance the analog and RF performance of DG MOSFET, an underlap dual-material (DM) DG MOSFET device structure has been considered because, it has the advantages of both underlap as well as that of dual-material gate (DMG). A 2D analytical surface potential, subthreshold current, subthreshold swing as well as transconductance modelling of underlap DMDG MOSFET has been done by solving the Poisson's equation. It has also been found that, numerically simulated data approves the analytically modelled data with commendable accuracy. As underlap length (Lun) increases, a substantial reduction of subthreshold current due to enhanced gate control over channel regime is observed. DMG structure facilitates to improve the average velocity of carriers which leads to superior drive current of the device. The underlap DMDG MOSFET device structure demonstrates an ameliorated subthreshold characteristic. The analog figure of merits (FOMs) such as transconductance (gm), transconductance generation factor (TGF), output conductance (gd), early voltage (VEA), intrinsic gain (AV) and RF FOMs namely cut-off frequency (fT), gain frequency product (GFP), transconductance frequency product (TFP) and gain transconductance frequency product (GTFP) have been evaluated. The aforesaid analysis revels that, the device is best suited for communication related Analog/RF applications.

77 FR 50722 - Software Unit Testing for Digital Computer Software Used in Safety Systems of Nuclear Power Plants

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-22

... NUCLEAR REGULATORY COMMISSION [NRC-2012-0195] Software Unit Testing for Digital Computer Software...) is issuing for public comment draft regulatory guide (DG), DG-1208, ``Software Unit Testing for Digital Computer Software used in Safety Systems of Nuclear Power Plants.'' The DG-1208 is proposed...

78 FR 65869 - Airworthiness Directives; DG Flugzeugbau GmbH Gliders

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-04

... Directives; DG Flugzeugbau GmbH Gliders AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final... Flugzeugbau GmbH Model DG-1000T glider equipped with a Solo Kleinmotoren Model 2350 C engine. This AD results... in this AD, contact Solo Kleinmotoren GmbH, Postfach 60 01 52, D 71050 Sindelfingen, Germany...

The CO2 Reduction Potential of Combined Heat and Power in California's Commercial Buildings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stadler, Michael; Marnay, Chris; Cardoso, Goncalo

2009-11-16

The Ernest Orlando Lawrence Berkeley National Laboratory (LBNL) is working with the California Energy Commission (CEC) to determine the potential role of commercial sector distributed generation (DG) with combined heat and power (CHP) capability deployment in greenhouse gas emissions (GHG) reductions. CHP applications at large industrial sites are well known, and a large share of their potential has already been harvested. In contrast, relatively little attention has been paid to the potential of medium-sized commercial buildings, i.e., ones with peak electric loads ranging from 100 kW to 5 MW. We examine how this sector might implement DG with CHP inmore » cost minimizing microgrids that are able to adopt and operate various energy technologies, such as solar photovoltaics (PV), on-site thermal generation, heat exchangers, solar thermal collectors, absorption chillers, and storage systems. We apply a mixed-integer linear program (MILP) that minimizes a site's annual energy costs as its objective. Using 138 representative mid-sized commercial sites in California (CA), existing tariffs of three major electricity distribution ultilities plus a natural gas company, and performance data of available technology in 2020, we find the GHG reduction potential for this CA commercial sector segment, which represents about 35percent of total statewide commercial sector sales. Under the assumptions made, in a reference case, this segment is estimated to be capable of economically installing 1.4 GW of CHP, 35percent of the California Air Resources Board (CARB) statewide 4 GW goal for total incremental CHP deployment by 2020. However, because CARB's assumed utilization is far higherthan is found by the MILP, the adopted CHP only contributes 19percent of the CO2 target. Several sensitivity runs were completed. One applies a simple feed-in tariff similar to net metering, and another includes a generous self-generation incentive program (SGIP) subsidy for fuel cells. The feed-in tariff proves ineffective at stimulating CHP deployment, while the SGIP buy down is more powerful. The attractiveness of CHP varies widely by climate zone and service territory, but in general, hotter inland areas and San Diego are the more attractive regions because high cooling loads achieve higher equipment utilization. Additionally, large office buildings are surprisingly good hosts for CHP, so large office buildings in San Diego and hotter urban centers emerge as promising target hosts. Overall the effect on CO2 emissions is limited, never exceeding 27percent of the CARB target. Nonetheless, results suggest that the CO2 emissions abatement potential of CHP in mid-sized CA buildings is significant, and much more promising than is typically assumed.« less

8-hydroxydeoxyguanosine suppresses NO production and COX-2 activity via Rac1/STATs signaling in LPS-induced brain microglia.

PubMed

Kim, Hong Sook; Ye, Sang-Kyu; Cho, Ik Hyun; Jung, Joo Eun; Kim, Dong-Hyun; Choi, Seongwon; Kim, Yong-Sik; Park, Chung-Gyu; Kim, Tae-Yoon; Lee, Jung Weon; Chung, Myung-Hee

2006-11-01

Free 8-hydroxydeoxyguanosine (oh(8)dG), a nucleoside of 8-hydroxyguanine (oh(8)Gua), present in cytosol is not incorporated into DNA. However, nothing is known about its biological function when it presents in cytosol as a free form. We demonstrate here for the first time that oh(8)dG inhibits lipopolysaccharide (LPS)-induced nitric oxide (NO) production and cyclooxygenase-2 (COX-2) activity, and both gene transcriptions in microglia. Furthermore, oh(8)dG reduced mRNA levels of pro-inflammatory cytokine, such as IL-1beta, IL-6, and TNF-alpha, in activated BV2 cells. We also found that oh(8)dG suppressed reactive oxygen species (ROS) production through reduction of NADPH oxidase activity and blocked Rac1/STATs signal cascade. Finally, oh(8)dG suppressed recruitment of STATs and p300 to the iNOS and COX-2 promoters, and inhibited H3 histone acetylation. Taken together, these results provide new aspects of oh(8)dG as an anti-inflammatory agent.

Control of nuclear β-dystroglycan content is crucial for the maintenance of nuclear envelope integrity and function.

PubMed

Vélez-Aguilera, Griselda; de Dios Gómez-López, Juan; Jiménez-Gutiérrez, Guadalupe E; Vásquez-Limeta, Alejandra; Laredo-Cisneros, Marco S; Gómez, Pablo; Winder, Steve J; Cisneros, Bulmaro

2018-02-01

β-Dystroglycan (β-DG) is a plasma membrane protein that has ability to target to the nuclear envelope (NE) to maintain nuclear architecture. Nevertheless, mechanisms controlling β-DG nuclear localization and the physiological consequences of a failure of trafficking are largely unknown. We show that β-DG has a nuclear export pathway in myoblasts that depends on the recognition of a nuclear export signal located in its transmembrane domain, by CRM1. Remarkably, NES mutations forced β-DG nuclear accumulation resulting in mislocalization and decreased levels of emerin and lamin B1 and disruption of various nuclear processes in which emerin (centrosome-nucleus linkage and β-catenin transcriptional activity) and lamin B1 (cell cycle progression and nucleoli structure) are critically involved. In addition to nuclear export, the lifespan of nuclear β-DG is restricted by its nuclear proteasomal degradation. Collectively our data show that control of nuclear β-DG content by the combination of CRM1 nuclear export and nuclear proteasome pathways is physiologically relevant to preserve proper NE structure and activity. Copyright © 2017 Elsevier B.V. All rights reserved.

Diethylentriaminepenta acetic acid glucose conjugates as a cell permeable iron chelator.

PubMed

Mosayebnia, Mona; Shafiee-Ardestani, Mehdi; Pasalar, Parvin; Mashayekhi, Mojgan; Amanlou, Massoud

2014-01-01

To find out whether DTPA-DG complex can enhance clearance of intracellular free iron. Diethylenetriaminepentaacetic acid-D-deoxy-glucosamine (DTPA-DG) was synthesized and examined for its activity as a cell-permeable iron chelator in human hepatocellular carcinoma (HEPG2) cell line exposed to high concentration of iron sulfate and compared with deferoxamine (DFO), a prototype iron chelator. The effect of DTPA-DG on cell viability was monitored using the 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide MTT assay as well. There was a significant increase of iron level after iron overload induction in HEPG2 cell culture. DTPA-DG presented a remarkable capacity to iron burden reducing with estimated 50% inhibitory concentration value of 65.77 nM. In fact, glycosyl moiety was gained access of DTPA to intracellular iron deposits through glucose transporter systems. DTPA-DG, more potent than DFO to sequester deposits of free iron with no profound toxic effect. The results suggest the potential of DTPA-DG in chelating iron and permitting its excretion from primary organ storage.

Graphene quantum dots-three-dimensional graphene composites for high-performance supercapacitors.

PubMed

Chen, Qing; Hu, Yue; Hu, Chuangang; Cheng, Huhu; Zhang, Zhipan; Shao, Huibo; Qu, Liangti

2014-09-28

Graphene quantum dots (GQDs) have been successfully deposited onto the three-dimensional graphene (3DG) by a benign electrochemical method and the ordered 3DG structure remains intact after the uniform deposition of GQDs. In addition, the capacitive properties of the as-formed GQD-3DG composites are evaluated in symmetrical supercapacitors. It is found that the supercapacitor fabricated from the GQD-3DG composite is highly stable and exhibits a high specific capacitance of 268 F g(-1), representing a more than 90% improvement over that of the supercapacitor made from pure 3DG electrodes (136 F g(-1)). Owing to the convenience of the current method, it can be further used in other well-defined electrode materials, such as carbon nanotubes, carbon aerogels and conjugated polymers to improve the performance of the supercapacitors.

Separation or binding? Role of the dentate gyrus in hippocampal mnemonic processing.

PubMed

Lee, Jong Won; Jung, Min Whan

2017-04-01

As a major component of the hippocampal trisynaptic circuit, the dentate gyrus (DG) relays inputs from the entorhinal cortex to the CA3 subregion. Although the anatomy of the DG is well characterized, its contribution to hippocampal mnemonic processing is still unclear. A currently popular theory proposes that the primary function of the DG is to orthogonalize incoming input patterns into non-overlapping patterns (pattern separation). We critically review the available data and conclude that the theoretical support and empirical evidence for this theory are not strong. We then review an alternative theory that posits a role for the DG in binding together different types of incoming sensory information. We conclude that 'binding' better captures the contribution of the DG to memory encoding than 'pattern separation'. Copyright © 2017 Elsevier Ltd. All rights reserved.

Arbitrary-Lagrangian-Eulerian Discontinuous Galerkin schemes with a posteriori subcell finite volume limiting on moving unstructured meshes

NASA Astrophysics Data System (ADS)

Boscheri, Walter; Dumbser, Michael

2017-10-01

We present a new family of high order accurate fully discrete one-step Discontinuous Galerkin (DG) finite element schemes on moving unstructured meshes for the solution of nonlinear hyperbolic PDE in multiple space dimensions, which may also include parabolic terms in order to model dissipative transport processes, like molecular viscosity or heat conduction. High order piecewise polynomials of degree N are adopted to represent the discrete solution at each time level and within each spatial control volume of the computational grid, while high order of accuracy in time is achieved by the ADER approach, making use of an element-local space-time Galerkin finite element predictor. A novel nodal solver algorithm based on the HLL flux is derived to compute the velocity for each nodal degree of freedom that describes the current mesh geometry. In our algorithm the spatial mesh configuration can be defined in two different ways: either by an isoparametric approach that generates curved control volumes, or by a piecewise linear decomposition of each spatial control volume into simplex sub-elements. Each technique generates a corresponding number of geometrical degrees of freedom needed to describe the current mesh configuration and which must be considered by the nodal solver for determining the grid velocity. The connection of the old mesh configuration at time tn with the new one at time t n + 1 provides the space-time control volumes on which the governing equations have to be integrated in order to obtain the time evolution of the discrete solution. Our numerical method belongs to the category of so-called direct Arbitrary-Lagrangian-Eulerian (ALE) schemes, where a space-time conservation formulation of the governing PDE system is considered and which already takes into account the new grid geometry (including a possible rezoning step) directly during the computation of the numerical fluxes. We emphasize that our method is a moving mesh method, as opposed to total Lagrangian formulations that are based on a fixed computational grid and which instead evolve the mapping of the reference configuration to the current one. Our new Lagrangian-type DG scheme adopts the novel a posteriori sub-cell finite volume limiter method recently developed in [62] for fixed unstructured grids. In this approach, the validity of the candidate solution produced in each cell by an unlimited ADER-DG scheme is verified against a set of physical and numerical detection criteria, such as the positivity of pressure and density, the absence of floating point errors (NaN) and the satisfaction of a relaxed discrete maximum principle (DMP) in the sense of polynomials. Those cells which do not satisfy all of the above criteria are flagged as troubled cells and are recomputed at the aid of a more robust second order TVD finite volume scheme. To preserve the subcell resolution capability of the original DG scheme, the FV limiter is run on a sub-grid that is 2 N + 1 times finer compared to the mesh of the original unlimited DG scheme. The new subcell averages are then gathered back into a high order DG polynomial by a usual conservative finite volume reconstruction operator. The numerical convergence rates of the new ALE ADER-DG schemes are studied up to fourth order in space and time and several test problems are simulated in order to check the accuracy and the robustness of the proposed numerical method in the context of the Euler and Navier-Stokes equations for compressible gas dynamics, considering both inviscid and viscous fluids. Finally, an application inspired by Inertial Confinement Fusion (ICF) type flows is considered by solving the Euler equations and the PDE of viscous and resistive magnetohydrodynamics (VRMHD).

Malondialdehyde-Deoxyguanosine Adduct Formation in Workers of Pathology Wards. The Role of Air Formaldehyde Exposure

PubMed Central

Romanazzi, Valeria; Munnia, Armelle; Piro, Sara; Allione, Alessandra; Ricceri, Fulvio; Guarrera, Simonetta; Pignata, Cristina; Matullo, Giuseppe; Wang, Poguang; Giese, Roger W.; Peluso, Marco

2010-01-01

Background Formaldehyde is a ubiquitous pollutant to which humans are exposed. Pathologists can experience high formaldehyde exposure levels. Formaldehyde – among other properties – induce oxidative stress and free radicals, which react with DNA and lipids, leading to oxidative damage and lipid peroxidation, respectively. We measured the levels of air-formaldehyde exposure in a group of Italian pathologists and controls. We analyzed the effect of formaldehyde exposure on leukocyte malondialdehyde-deoxyguanosine adducts (M1-dG), a biomarker of oxidative stress and lipid peroxidation. We studied the relationship between air-formaldehyde and M1-dG adducts. Methods Air-formaldehyde levels were measured by personal air samplers. M1-dG adducts were analyzed by 32P-postlabelling assay. Results Reduction rooms pathologists were significantly exposed to air-formaldehyde in respect to controls and to the pathologists working in other laboratory areas (p<0.001). A significant difference for M1-dG adducts between exposed pathologists and controls was found (p=0.045). The effect becomes stronger when the evaluation of air-formaldehyde exposure was based on personal samplers (p=0.018). Increased M1dG adduct levels were only found in individuals exposed to air-formaldehyde concentrations higher than 66 μg/m3. When the exposed workers and controls were subgrouped according to smoking, M1-dG tended to increase in all the subjects but a significant association between M1-dG and air-formaldehyde was only found in not smokers (p= 0.009). Air formaldehyde played a role positive but not significant (r = 0.355, p = 0.075, Pearson correlation) in the formation of M1-dG, only in not smokers. Conclusions Working in the reduction rooms and to be exposed to air-formaldehyde concentrations higher than 66 μg/m3 is associated with increased levels of M1-dG adducts. PMID:20707408

The predictive power of the elimination of dioxin-like pollutants from pigs: an in vivo study.

PubMed

Shen, Heqing; Henkelmann, Bernhard; Rambeck, Walter Albert; Mayer, Richard; Wehr, Ulrich; Schramm, Karl-Werner

2012-01-01

Pigs accidentally given feed contaminated by dioxin-like pollutants are a serious public health issue. We have examined whether pigs with limited exposure during early periods of fattening would be categorized as non-compliant with the EU limit at slaughtering when growth-dilution, excretion and metabolism effects are considered. Sixteen female and sixteen castrated male weaned pigs were divided into four groups (e.g. DG0, DG1, DG2 and DG3) in week 2 after birth. From weeks 3 to 13, groups DG1, DG2, and DG3 pigs were fed with a polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) and polychlorinated biphenyl (PCB) mixture at dosages of 1, 10 and 100ng-toxic equivalent (TEQ) per kg dry mass feed in capsules, respectively. From weeks 13 to 23, the animals were nourished with clear feed. Control group DG0 was always fed with clear feed. Subcutaneous fat samples were collected at weeks 13, 18 and 23 by biopsies. The pollutant residues were analyzed by high resolution gas chromatography-high resolution mass spectrometry and quantified by a (13)C-isotope dilution method. The results showed the following: (1) when slaughtered at week 23, the TEQ for DG1 pigs (0.66±0.21pg/g fat) was under the EU limit of 1pg PCDD/F-TEQ/g fat; (2) PCDD/F congener-specific first-order elimination rates were linearly correlated with their toxicity equivalency factors (TEFs), and the rates were significantly dose-dependent for the more toxic congeners (TEF≥0.1). Therefore, the pigs' exposure above the EU limit during the early fattening stage did not necessarily lead to their categorization as non-compliant pork; and the residual TEQ for pork can be predicted from early exposure concentrations based on the models established here. Copyright © 2011 Elsevier Ltd. All rights reserved.

A tour about existence and uniqueness of dg enhancements and lifts

NASA Astrophysics Data System (ADS)

Canonaco, Alberto; Stellari, Paolo

2017-12-01

This paper surveys the recent advances concerning the relations between triangulated (or derived) categories and their dg enhancements. We explain when some interesting triangulated categories arising in algebraic geometry have a unique dg enhancement. This is the case, for example, for the unbounded derived category of quasi-coherent sheaves on an algebraic stack or for its full triangulated subcategory of perfect complexes. Moreover we give an account of the recent results about the possibility to lift exact functors between the bounded derived categories of coherent sheaves on smooth schemes to dg (quasi-)functors.

Definitive and differential diagnosis of desquamative gingivitis through direct immunofluorescence studies.

PubMed

Suresh, Lakshmanan; Neiders, Mirdza E

2012-10-01

Desquamative gingivitis (DG) is a common clinical manifestation of oral autoimmune vesiculobullous diseases (VBDs). Their polymorphous clinical presentations coupled with similar histologic features make diagnosis indistinguishable among the different VBDs. Direct immunofluorescence (IF) studies are valuable gold-standard diagnostic tests that allow for discrimination among the various VBDs that present with DG. There have been no recent detailed analyses done that have used conventional light microscopy and direct IF in diagnosis to document the clinical associations of DG with various autoimmune oral diseases. The aim of this study is to examine retrospectively a large cohort of patients with DG for associated diseases and to determine the utility of direct IF and conventional light microscopy in establishing a definitive diagnosis. During a 14-month period, our laboratory in Buffalo, New York, received 239 consecutive archival cases of gingival biopsy with a clinical diagnosis of DG. These specimens were submitted to establish or rule out a diagnosis of a direct IF-positive VBD. The demographic, clinical, and microscopic findings were tabulated using established inclusion and diagnostic criteria. Approximately half the number (48.1%) of biopsies received for direct IF studies were submitted by periodontists. Slightly more than half of the patients (53%) previously had biopsies submitted for both hematoxylin and eosin (H & E) and direct IF testing. There was a female predilection for all the diseases studied except for pemphigus and linear immunoglobulin A disease. Oral lichen planus was the most common disease presenting as DG, followed by pemphigoid. The clinical diagnosis of lichen planus correlated with the biopsy findings in 80% of the cases and with pemphigoid in 60%. Definitive diagnosis was rendered to ≈80% of the gingival biopsies submitted. Negative cases of direct IF presenting as DG had significant pathology, such as dysplasia and carcinoma, which would have been otherwise missed if H & E studies had not been performed. This study has the largest cohort of patients with DG suspected of VBD reported in the literature. The patients were predominantly females who had most often been seen by a periodontist. The definitive diagnosis of DG was most accurately achieved when H & E along with two biopsies for direct IF studies were submitted for testing. H & E studies were particularly important for definitive diagnosis of negative cases. Oral lichen planus was the most common disease presenting as DG, which is consistent with recent studies. Systemic connective tissue disorders that present as DG at initial clinical examination require direct IF and serum studies for a conclusive diagnosis. Clinical pathologic correlation, including history, presentation, H & E, and direct IF studies, are essential in establishing a definitive and differential diagnosis for cases presenting with DG.

Refinement of Perioperative Feeding in a Mouse Model of Vertical Sleeve Gastrectomy.

PubMed

Doerning, Carolyn M; Burlingame, Lisa A; Lewis, Alfor G; Myronovych, Andriy; Seeley, Randy J; Lester, Patrick A

2018-05-01

Provision of liquid enteral nutrition (LEN) during the perioperative period is standard practice for rodents undergoing bariatric surgery, yet these diets are associated with several challenges, including coagulation of the liquid diet within the delivery system and decreased postoperative consumption. We investigated the use of a commercially available high-calorie dietary gel supplement (DG) as an alternative food source for mice during the perioperative period. C57BL/6J male mice were fed high-fat diet for 8 to 10 wk prior to surgery. The study groups were: vertical sleeve gastrectomy (VSG) +DG, VSG+LEN, sham surgery+DG, and sham+LEN. Food and water intakes, body weight, and body fat composition was monitored throughout the study. Mice that received DG lost significantly more weight preoperatively than those fed LEN. However, during the postoperative period, body weight, body fat composition, and water and caloric intake were similar among all experimental diet groups. Three mice in the VSG+LEN group were euthanized due to clinical illness during the course of the study. In summary, feeding a high-calorie DG to mice undergoing VSG surgery is a viable alternative to LEN, given that DG does not significantly affect the surgical model of weight loss or result in adverse clinical outcomes. We recommend additional metabolic characterization of DG supplementation to ensure that this novel diet does not confound specific research goals in the murine VSG model.

A Reconstructed Discontinuous Galerkin Method for the Compressible Navier-Stokes Equations on Arbitrary Grids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong Luo; Luqing Luo; Robert Nourgaliev

2010-09-01

A reconstruction-based discontinuous Galerkin (RDG) method is presented for the solution of the compressible Navier–Stokes equations on arbitrary grids. The RDG method, originally developed for the compressible Euler equations, is extended to discretize viscous and heat fluxes in the Navier–Stokes equations using a so-called inter-cell reconstruction, where a smooth solution is locally reconstructed using a least-squares method from the underlying discontinuous DG solution. Similar to the recovery-based DG (rDG) methods, this reconstructed DG method eliminates the introduction of ad hoc penalty or coupling terms commonly found in traditional DG methods. Unlike rDG methods, this RDG method does not need tomore » judiciously choose a proper form of a recovered polynomial, thus is simple, flexible, and robust, and can be used on arbitrary grids. The developed RDG method is used to compute a variety of flow problems on arbitrary meshes to demonstrate its accuracy, efficiency, robustness, and versatility. The numerical results indicate that this RDG method is able to deliver the same accuracy as the well-known Bassi–Rebay II scheme, at a half of its computing costs for the discretization of the viscous fluxes in the Navier–Stokes equations, clearly demonstrating its superior performance over the existing DG methods for solving the compressible Navier–Stokes equations.« less

A Reconstructed Discontinuous Galerkin Method for the Compressible Navier-Stokes Equations on Arbitrary Grids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong Luo; Luqing Luo; Robert Nourgaliev

2010-01-01

A reconstruction-based discontinuous Galerkin (RDG) method is presented for the solution of the compressible Navier-Stokes equations on arbitrary grids. The RDG method, originally developed for the compressible Euler equations, is extended to discretize viscous and heat fluxes in the Navier-Stokes equations using a so-called inter-cell reconstruction, where a smooth solution is locally reconstructed using a least-squares method from the underlying discontinuous DG solution. Similar to the recovery-based DG (rDG) methods, this reconstructed DG method eliminates the introduction of ad hoc penalty or coupling terms commonly found in traditional DG methods. Unlike rDG methods, this RDG method does not need tomore » judiciously choose a proper form of a recovered polynomial, thus is simple, flexible, and robust, and can be used on arbitrary grids. The developed RDG method is used to compute a variety of flow problems on arbitrary meshes to demonstrate its accuracy, efficiency, robustness, and versatility. The numerical results indicate that this RDG method is able to deliver the same accuracy as the well-known Bassi-Rebay II scheme, at a half of its computing costs for the discretization of the viscous fluxes in the Navier-Stokes equations, clearly demonstrating its superior performance over the existing DG methods for solving the compressible Navier-Stokes equations.« less

Targeted Delivery of siRNA with pH-Responsive Hybrid Gold Nanostars for Cancer Treatment

PubMed Central

Zhu, Hongyan; Liu, Wanwan; Cheng, Ziting; Yao, Ke; Yang, Yu; Xu, Bohui

2017-01-01

In this work, we report the engineering of gold nanostars (GNS) to deliver small interfering RNA (siRNA) into HepG2 cells. The ligand DG-PEG-Lipoic acid (LA)-Lys-9R (hydrazone) was designed to functionalize GNS, and create the nanoparticles named as 9R/DG-GNS (hydrazone). In the ligand, 2-deoxyglucose (DG) is the targeting molecule, polyethylene glycol (PEG) helps to improve the dispersity and biocompatibility, 9-poly-d-arginine (9R) is employed to provide a positive surface charge and adsorb negative siRNA, and hydrazone bonds are pH-responsive and can avoid receptor-mediated endosomal recycling. Compared to GNS alone, 9R/DG-GNS (hydrazone) showed superior transfection efficiency. The expressions of cyclooxygenase-2 (COX-2) in HepG2 and SGC7901 cells were significantly suppressed by siRNA/9R/DG-GNS (hydrazone) complex. Notably, 9R/DG-GNS (hydrazone) possessed low cytotoxicity even at high concentrations in both normal cells and tumor cells. The combination treatment of siRNA/9R/DG-GNS (hydrazone) complex inhibited the cell growth rate by more than 75%. These results verified that the pH-responsive GNS complex is a promising siRNA delivery system for cancer therapy, and it is anticipated that near-infrared absorbing GNS with good photothermal conversion efficiency can be potentially used for photothermal therapy of tumors. PMID:28937584

Impaired neurogenesis of the dentate gyrus is associated with pattern separation deficits: A computational study.

PubMed

Faghihi, Faramarz; Moustafa, Ahmed A

2016-09-01

The separation of input patterns received from the entorhinal cortex (EC) by the dentate gyrus (DG) is a well-known critical step of information processing in the hippocampus. Although the role of interneurons in separation pattern efficiency of the DG has been theoretically known, the balance of neurogenesis of excitatory neurons and interneurons as well as its potential role in information processing in the DG is not fully understood. In this work, we study separation efficiency of the DG for different rates of neurogenesis of interneurons and excitatory neurons using a novel computational model in which we assume an increase in the synaptic efficacy between excitatory neurons and interneurons and then its decay over time. Information processing in the EC and DG was simulated as information flow in a two layer feed-forward neural network. The neurogenesis rate was modeled as the percentage of new born neurons added to the neuronal population in each time bin. The results show an important role of an optimal neurogenesis rate of interneurons and excitatory neurons in the DG in efficient separation of inputs from the EC in pattern separation tasks. The model predicts that any deviation of the optimal values of neurogenesis rates leads to different decreased levels of the separation deficits of the DG which influences its function to encode memory.

A validated bioanalytical HPLC method for pharmacokinetic evaluation of 2-deoxyglucose in human plasma

PubMed Central

Gounder, Murugesan K.; Lin, Hongxia; Stein, Mark; Goodin, Susan; Bertino, Joseph R.; Kong, Ah-Ng Tony; DiPaola, Robert S.

2015-01-01

2-deoxyglucose (2-DG), an analog of glucose, is widely used to interfere with the glycolysis in tumor cells and studied as a therapeutic approach in clinical trials. To evaluate the pharmacokinetics of 2-DG, we describe the development and validation of a sensitive HPLC fluorescent method for the quantitation of 2-DG in plasma. Plasma samples were deproteinized with methanol and the supernatant was dried at 45°C. The residues were dissolved in methanolic sodium acetate/boric acid solution. 2-DG and other monosaccharides were derivatized to 2-aminobenzoic acid derivatives in a single step in the presence of sodium cyanoborohydride at 80°C for 45min. The analytes were separated on a YMC ODS C18 reversed-phase column using gradient elution. The excitation and emission wavelengths were set at 360 and 425nm. The 2-DG calibration curves were linear over the range of 0.63 to 300μg/mL with the limit of detection of 0.5μg/mL. The assay provided satisfactory intra-day and inter-day precision with RSD less than 9.8% and the accuracy ranged from 86.8% to 110.0%. The HPLC method is reproducible and suitable for the quantitation of 2-DG in plasma. The method was successfully applied to characterize the pharmacokinetics profile of 2-DG in patients with advanced solid tumors. PMID:21932382

Regionally Implicit Discontinuous Galerkin Methods for Solving the Relativistic Vlasov-Maxwell System Submitted to Iowa State University

NASA Astrophysics Data System (ADS)

Guthrey, Pierson Tyler

The relativistic Vlasov-Maxwell system (RVM) models the behavior of collisionless plasma, where electrons and ions interact via the electromagnetic fields they generate. In the RVM system, electrons could accelerate to significant fractions of the speed of light. An idea that is actively being pursued by several research groups around the globe is to accelerate electrons to relativistic speeds by hitting a plasma with an intense laser beam. As the laser beam passes through the plasma it creates plasma wakes, much like a ship passing through water, which can trap electrons and push them to relativistic speeds. Such setups are known as laser wakefield accelerators, and have the potential to yield particle accelerators that are significantly smaller than those currently in use. Ultimately, the goal of such research is to harness the resulting electron beams to generate electromagnetic waves that can be used in medical imaging applications. High-order accurate numerical discretizations of kinetic Vlasov plasma models are very effective at yielding low-noise plasma simulations, but are computationally expensive to solve because of the high dimensionality. In addition to the general difficulties inherent to numerically simulating Vlasov models, the relativistic Vlasov-Maxwell system has unique challenges not present in the non-relativistic case. One such issue is that operator splitting of the phase gradient leads to potential instabilities, thus we require an alternative to operator splitting of the phase. The goal of the current work is to develop a new class of high-order accurate numerical methods for solving kinetic Vlasov models of plasma. The main discretization in configuration space is handled via a high-order finite element method called the discontinuous Galerkin method (DG). One difficulty is that standard explicit time-stepping methods for DG suffer from time-step restrictions that are significantly worse than what a simple Courant-Friedrichs-Lewy (CFL) argument requires. The maximum stable time-step scales inversely with the highest degree in the DG polynomial approximation space and becomes progressively smaller with each added spatial dimension. In this work, we overcome this difficulty by introducing a novel time-stepping strategy: the regionally-implicit discontinuous Galerkin (RIDG) method. The RIDG is method is based on an extension of the Lax-Wendroff DG (LxW-DG) method, which previously had been shown to be equivalent (for linear constant coefficient problems) to a predictor-corrector approach, where the prediction is computed by a space-time DG method (STDG). The corrector is an explicit method that uses the space-time reconstructed solution from the predictor step. In this work, we modify the predictor to include not just local information, but also neighboring information. With this modification, we show that the stability is greatly enhanced; we show that we can remove the polynomial degree dependence of the maximum time-step and show vastly improved time-steps in multiple spatial dimensions. Upon the development of the general RIDG method, we apply it to the non-relativistic 1D1V Vlasov-Poisson equations and the relativistic 1D2V Vlasov-Maxwell equations. For each we validate the high-order method on several test cases. In the final test case, we demonstrate the ability of the method to simulate the acceleration of electrons to relativistic speeds in a simplified test case.

Combined inhibition of glycolysis and AMPK induces synergistic breast cancer cell killing

PubMed Central

Wu, Yong; Sarkissyan, Marianna; Mcghee, Eva; Lee, Sangkyu

2015-01-01

Targeting glycolysis for cancer treatment has been investigated as a therapeutic method but has not offered a feasible chemotherapeutic strategy. Our aim was to examine whether AMP-activated protein kinase (AMPK), a conditional oncogene, rescues the energetic stress and cytotoxicity induced by 2-deoxyglucose (2-DG), a glycolytic inhibitor, and the related mechanisms. Luciferin/luciferase adenosine triphosphate (ATP) determination, Western analysis, qRT-PCR analyses, MTT growth assay, clonogenic assay, and statistical analysis were performed in this study. 2-DG decreased ATP levels and subsequently activated AMPK, which contribute to intracellular ATP recovery in MCF-7 cells thus exhibiting no apparent cytotoxicity. Compound C, an AMPK inhibitor, further potentiates 2-DG-induced decrease in ATP levels and inhibits their recovery. 2-DG, via AMPK activation, stimulated cAMP response element-binding protein (CREB) phosphorylation and activity and promoted nuclear peroxisome proliferator-activated receptor gamma coactivator-1-beta (PGC-1β) and estrogen-related receptor α (ERRα) protein expression, leading to augmented mitochondrial biogenesis and expression of fatty acid oxidation (FAO) genes including PPARα, MCAD, CPT1C, and ACO. This metabolic adaptation elicited by AMPK counteracts the ATP-depleting and cancer cell-killing effect of 2-DG. However, 2-DG in combination with AMPK antagonists or small interfering RNA caused a dramatic increase in cytotoxicity in MCF-7 but not in MCF-10A cells. Similarly, when combined with inhibition of CREB/PGC-1β/ERRα pathway, 2-DG saliently suppressed mitochondrial biogenesis and the expression of FAO genes, depleted ATP production, and enhanced cytotoxicity in cancer cells. Collectively, the combination of 2-DG and AMPK inhibition synergistically enhanced the cytotoxic potential in breast cancer cells with a relative nontoxicity to normal cells and may offer a promising, safe, and effective breast cancer therapeutic strategy. PMID:25975952

Endoplasmic reticulum stress (ER-stress) by 2-deoxy-D-glucose (2DG) reduces cyclooxygenase-2 (COX-2) expression and N-glycosylation and induces a loss of COX-2 activity via a Src kinase-dependent pathway in rabbit articular chondrocytes.

PubMed

Yu, Seon-Mi; Kim, Song-Ja

2010-11-30

Endoplasmic reticulum (ER) stress regulates a wide range of cellular responses including apoptosis, proliferation, inflammation, and differentiation in mammalian cells. In this study, we observed the role of 2-deoxy-D-glucose (2DG) on inflammation of chondrocytes. 2DG is well known as an inducer of ER stress, via inhibition of glycolysis and glycosylation. Treatment of 2DG in chondrocytes considerably induced ER stress in a dose- and time-dependent manner, which was demonstrated by a reduction of glucose regulated protein of 94 kDa (grp94), an ER stress-inducible protein, as determined by a Western blot analysis. In addition, induction of ER stress by 2DG led to the expression of COX-2 protein with an apparent molecular mass of 66-70kDa as compared with the normally expressed 72-74 kDa protein. The suppression of ER stress with salubrinal (Salub), a selective inhibitor of eif2-alpha dephosphorylation, successfully prevented grp94 induction and efficiently recovered 2DG- modified COX-2 molecular mass and COX-2 activity might be associated with COX-2 N-glycosylation. Also, treatment of 2DG increased phosphorylation of Src in chondrocytes. The inhibition of the Src signaling pathway with PP2 (Src tyrosine kinase inhibitor) suppressed grp94 expression and restored COX-2 expression, N-glycosylation, and PGE2 production, as determined by a Western blot analysis and PGE2 assay. Taken together, our results indicate that the ER stress induced by 2DG results in a decrease of the transcription level, the molecular mass, and the activity of COX-2 in rabbit articular chondrocytes via a Src kinase-dependent pathway.

Adiponectin regulates contextual fear extinction and intrinsic excitability of dentate gyrus granule neurons through AdipoR2 receptors

PubMed Central

Zhang, D; Wang, X; Wang, B; Garza, J C; Fang, X; Wang, J; Scherer, P E; Brenner, R; Zhang, W; Lu, X-Y

2017-01-01

Post-traumatic stress disorder (PTSD) is characterized by exaggerated fear expression and impaired fear extinction. The underlying molecular and cellular mechanisms of PTSD are largely unknown. The current pharmacological and non-pharmacological treatments for PTSD are either ineffective or temporary with high relapse rates. Here we report that adiponectin-deficient mice exhibited normal contextual fear conditioning but displayed slower extinction learning. Infusions of adiponectin into the dentate gyrus (DG) of the hippocampus in fear-conditioned mice facilitated extinction of contextual fear. Whole-cell patch-clamp recordings in brain slices revealed that intrinsic excitability of DG granule neurons was enhanced by adiponectin deficiency and suppressed after treatment with the adiponectin mimetic AdipoRon, which were associated with increased input resistance and hyperpolarized resting membrane potential, respectively. Moreover, deletion of AdipoR2, but not AdipoR1 in the DG, resulted in augmented fear expression and reduced extinction, accompanied by intrinsic hyperexcitability of DG granule neurons. Adiponectin and AdipoRon failed to induce facilitation of fear extinction and elicit inhibition of intrinsic excitability of DG neurons in AdipoR2 knockout mice. These results indicated that adiponectin action via AdipoR2 was both necessary and sufficient for extinction of contextual fear and intrinsic excitability of DG granule neurons, implying that enhancing or dampening DG neuronal excitability may cause resistance to or facilitation of extinction. Therefore, our findings provide a functional link between adiponectin/AdipoR2 activation, DG neuronal excitability and contextual fear extinction, and suggest that targeting adiponectin/AdipoR2 may be used to strengthen extinction-based exposure therapies for PTSD. PMID:27137743

ANTICONVULSANT AND ANTIEPILEPTIC ACTIONS OF 2-DEOXY-DGLUCOSE IN EPILEPSY MODELS

PubMed Central

Stafstrom, Carl E.; Ockuly, Jeffrey C.; Murphree, Lauren; Valley, Matthew T.; Roopra, Avtar; Sutula, Thomas P.

2009-01-01

Objective Conventional anticonvulsants reduce neuronal excitability through effects on ion channels and synaptic function. Anticonvulsant mechanisms of the ketogenic diet remain incompletely understood. Since carbohydrates are restricted in patients on the ketogenic diet, we evaluated the effects of limiting carbohydrate availability by reducing glycolysis using the glycolytic inhibitor 2-deoxy-D-glucose (2DG) in experimental models of seizures and epilepsy. Methods Acute anticonvulsant actions of 2DG were assessed in vitro in rat hippocampal slices perfused with 7.5mM [K+]o, 4-aminopyridine (4-AP), or bicuculline and in vivo against seizures evoked by 6 Hz stimulation in mice, audiogenic stimulation in Fring’s mice, and maximal electroshock and subcutaneous Metrazol in rats. Chronic antiepileptic effects of 2DG were evaluated in rats kindled from olfactory bulb or perforant path. Results 2DG (10mM) reduced interictal epileptiform bursts induced by high [K+]o, 4-AP and bicuculline, and electrographic seizures induced by high [K+]o in CA3 of hippocampus. 2DG reduced seizures evoked by 6 Hz stimulation in mice (ED50 = 79.7 mg/kg) and audiogenic stimulation in Fring’s mice (ED50 = 206.4 mg/kg). 2DG exerted chronic antiepileptic action by increasing afterdischarge thresholds in perforant path (but not olfactory bulb) kindling and caused a 2-fold slowing in progression of kindled seizures at both stimulation sites. 2DG did not protect against maximal electroshock or Metrazol seizures. Interpretation The glycolytic inhibitor 2DG exerts acute anticonvulsant and chronic antiepileptic actions and has a novel pattern of effectiveness in preclinical screening models. These results identify metabolic regulation as a potential therapeutic target for seizure suppression and modification of epileptogenesis. PMID:19399874

Gambling, disordered gambling and their association with major depression and substance use: a web-based cohort and twin-sibling study.

PubMed

Blanco, C; Myers, J; Kendler, K S

2012-03-01

Relatively little is known about the environmental and genetic contributions to gambling frequency and disordered gambling (DG), the full continuum of gambling-related problems that includes pathological gambling (PG). A web-based sample (n=43,799 including both members of 609 twin and 303 sibling pairs) completed assessments of number of lifetime gambling episodes, DSM-IV criteria for PG, alcohol, nicotine and caffeine intake, and nicotine dependence (ND) and DSM-III-R criteria for lifetime major depression (MD). Twin modeling was performed using Mx. In the entire cohort, symptoms of DG indexed a single dimension of liability. Symptoms of DG were weakly related to caffeine intake and moderately related to MD, consumption of cigarettes and alcohol, and ND. In twin and sibling pairs, familial resemblance for number of times gambled resulted from both familial-environmental (c²=42%) and genetic factors (a²=32%). For symptoms of DG, resemblance resulted solely from genetic factors (a²=83%). Bivariate analyses indicated a low genetic correlation between symptoms of DG and MD (r(a)=+0.14) whereas genetic correlations with DG symptoms were substantially higher with use of alcohol, caffeine and nicotine, and ND (ranging from +0.29 to +0.80). The results were invariant across genders. Whereas gambling participation is determined by shared environmental and genetic factors, DG constitutes a single latent dimension that is largely genetically determined and more closely related to externalizing than internalizing behaviors. Because these findings are invariant across genders, they suggest that the etiological factors of DG are likely to be similar in men and women.

Adiponectin regulates contextual fear extinction and intrinsic excitability of dentate gyrus granule neurons through AdipoR2 receptors.

PubMed

Zhang, D; Wang, X; Wang, B; Garza, J C; Fang, X; Wang, J; Scherer, P E; Brenner, R; Zhang, W; Lu, X-Y

2017-07-01

Post-traumatic stress disorder (PTSD) is characterized by exaggerated fear expression and impaired fear extinction. The underlying molecular and cellular mechanisms of PTSD are largely unknown. The current pharmacological and non-pharmacological treatments for PTSD are either ineffective or temporary with high relapse rates. Here we report that adiponectin-deficient mice exhibited normal contextual fear conditioning but displayed slower extinction learning. Infusions of adiponectin into the dentate gyrus (DG) of the hippocampus in fear-conditioned mice facilitated extinction of contextual fear. Whole-cell patch-clamp recordings in brain slices revealed that intrinsic excitability of DG granule neurons was enhanced by adiponectin deficiency and suppressed after treatment with the adiponectin mimetic AdipoRon, which were associated with increased input resistance and hyperpolarized resting membrane potential, respectively. Moreover, deletion of AdipoR2, but not AdipoR1 in the DG, resulted in augmented fear expression and reduced extinction, accompanied by intrinsic hyperexcitability of DG granule neurons. Adiponectin and AdipoRon failed to induce facilitation of fear extinction and elicit inhibition of intrinsic excitability of DG neurons in AdipoR2 knockout mice. These results indicated that adiponectin action via AdipoR2 was both necessary and sufficient for extinction of contextual fear and intrinsic excitability of DG granule neurons, implying that enhancing or dampening DG neuronal excitability may cause resistance to or facilitation of extinction. Therefore, our findings provide a functional link between adiponectin/AdipoR2 activation, DG neuronal excitability and contextual fear extinction, and suggest that targeting adiponectin/AdipoR2 may be used to strengthen extinction-based exposure therapies for PTSD.

Active distribution network planning considering linearized system loss

NASA Astrophysics Data System (ADS)

Li, Xiao; Wang, Mingqiang; Xu, Hao

2018-02-01

In this paper, various distribution network planning techniques with DGs are reviewed, and a new distribution network planning method is proposed. It assumes that the location of DGs and the topology of the network are fixed. The proposed model optimizes the capacities of DG and the optimal distribution line capacity simultaneously by a cost/benefit analysis and the benefit is quantified by the reduction of the expected interruption cost. Besides, the network loss is explicitly analyzed in the paper. For simplicity, the network loss is appropriately simplified as a quadratic function of difference of voltage phase angle. Then it is further piecewise linearized. In this paper, a piecewise linearization technique with different segment lengths is proposed. To validate its effectiveness and superiority, the proposed distribution network planning model with elaborate linearization technique is tested on the IEEE 33-bus distribution network system.

The Discontinuous Galerkin Finite Element Method for Solving the MEG and the Combined MEG/EEG Forward Problem

PubMed Central

Piastra, Maria Carla; Nüßing, Andreas; Vorwerk, Johannes; Bornfleth, Harald; Oostenveld, Robert; Engwer, Christian; Wolters, Carsten H.

2018-01-01

In Electro- (EEG) and Magnetoencephalography (MEG), one important requirement of source reconstruction is the forward model. The continuous Galerkin finite element method (CG-FEM) has become one of the dominant approaches for solving the forward problem over the last decades. Recently, a discontinuous Galerkin FEM (DG-FEM) EEG forward approach has been proposed as an alternative to CG-FEM (Engwer et al., 2017). It was shown that DG-FEM preserves the property of conservation of charge and that it can, in certain situations such as the so-called skull leakages, be superior to the standard CG-FEM approach. In this paper, we developed, implemented, and evaluated two DG-FEM approaches for the MEG forward problem, namely a conservative and a non-conservative one. The subtraction approach was used as source model. The validation and evaluation work was done in statistical investigations in multi-layer homogeneous sphere models, where an analytic solution exists, and in a six-compartment realistically shaped head volume conductor model. In agreement with the theory, the conservative DG-FEM approach was found to be superior to the non-conservative DG-FEM implementation. This approach also showed convergence with increasing resolution of the hexahedral meshes. While in the EEG case, in presence of skull leakages, DG-FEM outperformed CG-FEM, in MEG, DG-FEM achieved similar numerical errors as the CG-FEM approach, i.e., skull leakages do not play a role for the MEG modality. In particular, for the finest mesh resolution of 1 mm sources with a distance of 1.59 mm from the brain-CSF surface, DG-FEM yielded mean topographical errors (relative difference measure, RDM%) of 1.5% and mean magnitude errors (MAG%) of 0.1% for the magnetic field. However, if the goal is a combined source analysis of EEG and MEG data, then it is highly desirable to employ the same forward model for both EEG and MEG data. Based on these results, we conclude that the newly presented conservative DG-FEM can at least complement and in some scenarios even outperform the established CG-FEM approaches in EEG or combined MEG/EEG source analysis scenarios, which motivates a further evaluation of DG-FEM for applications in bioelectromagnetism. PMID:29456487

Too Fast to Measure: Network Adjustment of Rapidly Changing Gravity Fields

NASA Astrophysics Data System (ADS)

Kennedy, J.; Ferre, T. P. A.

2014-12-01

Measurements of spatially-variable gravity at the field scale are difficult; measurements of the time-varying field even more so. Every previous gravity survey using relative gravimeters—still the workhorse of gravity studies, despite their nearly 80 year history—has assumed a static gravity field during the course of a survey, which may last days to weeks. With recently-improved instrumentation, however, measurements of fields changing on the order of tens of nm/sec2 per day are now possible. In particular, the A-10 portable absolute gravimeter provides not only absolute control, but also the change in that control during the course of a survey. Using digitally-recording spring-based relative gravimeters (namely, the ZLS Burris meter and the Scintrex CG-5), with their more efficient data collection and lower drift than previous generations, many more data are collected in a day. We demonstrate a method for incorporating in the least-squares network adjustment of relative gravity data a relation between the rate of change of gravity, dg, and distance from an infiltration source, x. This relation accounts for the fact that gravity at stations adjacent to the infiltration source changes more rapidly than stations further away; if all measurements collected over several days are to be included in a single network-adjustment, consideration of this change is required. Two methods are used to simulate the dg(x) relation: a simple model where dg is a linear function of x, and a coupled-hydrogeophysical method where a groundwater flow model predicts the nonlinear spatial variation of dg. Then, the change in gravity between different, independently adjusted surveys is used to parameterize the groundwater model. Data from two recent field examples, an artificial recharge facility near Tucson, Arizona, USA, and from the 2014 Lower Colorado River pulse flow experiment, clearly show the need to account for gravity change during a survey; maximum rates of change for the two studies were up to 30 and 50 nm/sec2 per day, respectively.

Dynamic Rupture Benchmarking of the ADER-DG Method

NASA Astrophysics Data System (ADS)

Gabriel, Alice; Pelties, Christian

2013-04-01

We will verify the arbitrary high-order derivative Discontinuous Galerkin (ADER-DG) method in various test cases of the 'SCEC/USGS Dynamic Earthquake Rupture Code Verification Exercise' benchmark suite (Harris et al. 2009). The ADER-DG scheme is able to solve the spontaneous rupture problem with high-order accuracy in space and time on three-dimensional unstructured tetrahedral meshes. Strong mesh coarsening or refinement at areas of interest can be applied to keep the computational costs feasible. Moreover, the method does not generate spurious high-frequency contributions in the slip rate spectra and therefore does not require any artificial damping as demonstrated in previous presentations and publications (Pelties et al. 2010 and 2012). We will show that the mentioned features hold also for more advanced setups as e.g. a branching fault system, heterogeneous background stresses and bimaterial faults. The advanced geometrical flexibility combined with an enhanced accuracy will make the ADER-DG method a useful tool to study earthquake dynamics on complex fault systems in realistic rheologies. References: Harris, R.A., M. Barall, R. Archuleta, B. Aagaard, J.-P. Ampuero, H. Bhat, V. Cruz-Atienza, L. Dalguer, P. Dawson, S. Day, B. Duan, E. Dunham, G. Ely, Y. Kaneko, Y. Kase, N. Lapusta, Y. Liu, S. Ma, D. Oglesby, K. Olsen, A. Pitarka, S. Song, and E. Templeton, The SCEC/USGS Dynamic Earthquake Rupture Code Verification Exercise, Seismological Research Letters, vol. 80, no. 1, pages 119-126, 2009 Pelties, C., J. de la Puente, and M. Kaeser, Dynamic Rupture Modeling in Three Dimensions on Unstructured Meshes Using a Discontinuous Galerkin Method, AGU 2010 Fall Meeting, abstract #S21C-2068 Pelties, C., J. de la Puente, J.-P. Ampuero, G. Brietzke, and M. Kaeser, Three-Dimensional Dynamic Rupture Simulation with a High-order Discontinuous Galerkin Method on Unstructured Tetrahedral Meshes, JGR. - Solid Earth, VOL. 117, B02309, 2012

Dynamic Rupture Benchmarking of the ADER-DG Method

NASA Astrophysics Data System (ADS)

Pelties, C.; Gabriel, A.

2012-12-01

We will verify the arbitrary high-order derivative Discontinuous Galerkin (ADER-DG) method in various test cases of the 'SCEC/USGS Dynamic Earthquake Rupture Code Verification Exercise' benchmark suite (Harris et al. 2009). The ADER-DG scheme is able to solve the spontaneous rupture problem with high-order accuracy in space and time on three-dimensional unstructured tetrahedral meshes. Strong mesh coarsening or refinement at areas of interest can be applied to keep the computational costs feasible. Moreover, the method does not generate spurious high-frequency contributions in the slip rate spectra and therefore does not require any artificial damping as demonstrated in previous presentations and publications (Pelties et al. 2010 and 2012). We will show that the mentioned features hold also for more advanced setups as e.g. a branching fault system, heterogeneous background stresses and bimaterial faults. The advanced geometrical flexibility combined with an enhanced accuracy will make the ADER-DG method a useful tool to study earthquake dynamics on complex fault systems in realistic rheologies. References: Harris, R.A., M. Barall, R. Archuleta, B. Aagaard, J.-P. Ampuero, H. Bhat, V. Cruz-Atienza, L. Dalguer, P. Dawson, S. Day, B. Duan, E. Dunham, G. Ely, Y. Kaneko, Y. Kase, N. Lapusta, Y. Liu, S. Ma, D. Oglesby, K. Olsen, A. Pitarka, S. Song, and E. Templeton, The SCEC/USGS Dynamic Earthquake Rupture Code Verification Exercise, Seismological Research Letters, vol. 80, no. 1, pages 119-126, 2009 Pelties, C., J. de la Puente, and M. Kaeser, Dynamic Rupture Modeling in Three Dimensions on Unstructured Meshes Using a Discontinuous Galerkin Method, AGU 2010 Fall Meeting, abstract #S21C-2068 Pelties, C., J. de la Puente, J.-P. Ampuero, G. Brietzke, and M. Kaeser, Three-Dimensional Dynamic Rupture Simulation with a High-order Discontinuous Galerkin Method on Unstructured Tetrahedral Meshes, JGR. - Solid Earth, VOL. 117, B02309, 2012

Lactobacillus casei DG and its postbiotic reduce the inflammatory mucosal response: an ex-vivo organ culture model of post-infectious irritable bowel syndrome.

PubMed

Compare, Debora; Rocco, Alba; Coccoli, Pietro; Angrisani, Debora; Sgamato, Costantino; Iovine, Barbara; Salvatore, Umberto; Nardone, Gerardo

2017-04-14

The evidence on the role of gut microbiota in post-infectious irritable bowel syndrome (PI-IBS) is convincing. Lactobacillus spp. positively affect IBS symptoms, although the mechanisms through which probiotics exert their beneficial effects are largely unknown. The aim of the study is to evaluate the role of Lactobacillus casei DG (LC-DG) and its postbiotic (PB) in modulating the inflammatory/immune-response in PI-IBS in an ex-vivo organ culture model. Ex vivo cultures of ileal and colonic mucosa from 10 PI-IBS, diarrhea predominant subtype (D) patients, and 10 healthy controls (HC) were treated with LPS, LC-DG and PB. Interleukin (IL)-1α, IL-6, IL-8 and IL-10 mRNA levels were assessed by real-time PCR and Toll like receptor 4 (TLR-4) protein expression by Western blotting. At baseline, IL-1α, IL-6 and IL-8 mRNA levels as well as TLR-4 protein expression were significantly higher while IL-10 mRNA levels were lower in PI-IBS D than in HC in both ileum and colon. LC-DG and PB significantly reduced the mRNA levels of pro-inflammatory cytokines and TLR-4 while increased that of IL-10 after LPS stimulation. The protective effect was more pronounced for PB than LC-DG treatment. LC-DG and its PB attenuate the inflammatory mucosal response in an ex-vivo organ culture model of PI-IBS D.

A validated bioanalytical HPLC method for pharmacokinetic evaluation of 2-deoxyglucose in human plasma.

PubMed

Gounder, Murugesan K; Lin, Hongxia; Stein, Mark; Goodin, Susan; Bertino, Joseph R; Kong, Ah-Ng Tony; DiPaola, Robert S

2012-05-01

2-Deoxyglucose (2-DG), an analog of glucose, is widely used to interfere with glycolysis in tumor cells and studied as a therapeutic approach in clinical trials. To evaluate the pharmacokinetics of 2-DG, we describe the development and validation of a sensitive HPLC fluorescent method for the quantitation of 2-DG in plasma. Plasma samples were deproteinized with methanol and the supernatant was dried at 45°C. The residues were dissolved in methanolic sodium acetate-boric acid solution. 2-DG and other monosaccharides were derivatized to 2-aminobenzoic acid derivatives in a single step in the presence of sodium cyanoborohydride at 80°C for 45 min. The analytes were separated on a YMC ODS C₁₈ reversed-phase column using gradient elution. The excitation and emission wavelengths were set at 360 and 425 nm. The 2-DG calibration curves were linear over the range of 0.63-300 µg/mL with a limit of detection of 0.5 µg/mL. The assay provided satisfactory intra-day and inter-day precision with RSD less than 9.8%, and the accuracy ranged from 86.8 to 110.0%. The HPLC method is reproducible and suitable for the quantitation of 2-DG in plasma. The method was successfully applied to characterize the pharmacokinetics profile of 2-DG in patients with advanced solid tumors. Copyright © 2011 John Wiley & Sons, Ltd.

Space-time adaptive ADER-DG schemes for dissipative flows: Compressible Navier-Stokes and resistive MHD equations

NASA Astrophysics Data System (ADS)

Fambri, Francesco; Dumbser, Michael; Zanotti, Olindo

2017-11-01

This paper presents an arbitrary high-order accurate ADER Discontinuous Galerkin (DG) method on space-time adaptive meshes (AMR) for the solution of two important families of non-linear time dependent partial differential equations for compressible dissipative flows : the compressible Navier-Stokes equations and the equations of viscous and resistive magnetohydrodynamics in two and three space-dimensions. The work continues a recent series of papers concerning the development and application of a proper a posteriori subcell finite volume limiting procedure suitable for discontinuous Galerkin methods (Dumbser et al., 2014, Zanotti et al., 2015 [40,41]). It is a well known fact that a major weakness of high order DG methods lies in the difficulty of limiting discontinuous solutions, which generate spurious oscillations, namely the so-called 'Gibbs phenomenon'. In the present work, a nonlinear stabilization of the scheme is sequentially and locally introduced only for troubled cells on the basis of a novel a posteriori detection criterion, i.e. the MOOD approach. The main benefits of the MOOD paradigm, i.e. the computational robustness even in the presence of strong shocks, are preserved and the numerical diffusion is considerably reduced also for the limited cells by resorting to a proper sub-grid. In practice the method first produces a so-called candidate solution by using a high order accurate unlimited DG scheme. Then, a set of numerical and physical detection criteria is applied to the candidate solution, namely: positivity of pressure and density, absence of floating point errors and satisfaction of a discrete maximum principle in the sense of polynomials. Furthermore, in those cells where at least one of these criteria is violated the computed candidate solution is detected as troubled and is locally rejected. Subsequently, a more reliable numerical solution is recomputed a posteriori by employing a more robust but still very accurate ADER-WENO finite volume scheme on the subgrid averages within that troubled cell. Finally, a high order DG polynomial is reconstructed back from the evolved subcell averages. We apply the whole approach for the first time to the equations of compressible gas dynamics and magnetohydrodynamics in the presence of viscosity, thermal conductivity and magnetic resistivity, therefore extending our family of adaptive ADER-DG schemes to cases for which the numerical fluxes also depend on the gradient of the state vector. The distinguished high-resolution properties of the presented numerical scheme standout against a wide number of non-trivial test cases both for the compressible Navier-Stokes and the viscous and resistive magnetohydrodynamics equations. The present results show clearly that the shock-capturing capability of the news schemes is significantly enhanced within a cell-by-cell Adaptive Mesh Refinement (AMR) implementation together with time accurate local time stepping (LTS).

Recruiters, Advertising, and Navy Enlistments.

DTIC Science & Technology

1980-03-01

Population’s Awareness and Advertising Previous studies on advertising have focused on measuring its effects in product markets : the consensus is that...needed that would have an immediate effect. Since about half of the HSGs generated by advertising accrue after the second year, the proper strategy is...1 June 1973. 4. Clarke, D.G., "Econometric Measurement of the Duration of Advertising Effect on Sales," Journal of Marketing Research, Vol. III

Measuring the health of populations: the veil of ignorance approach.

PubMed

Pinto-Prades, José-Luis; Abellán-Perpiñán, José-María

2005-01-01

We report the results from two surveys designed to explore whether an application of Harsanyi's principle of choice form behind a veil of ignorance (VEI) can be used in order to measure the health of populations. This approach was tentatively recommended by Murray et al. (Bull. World Health Organ 2000; 78: 981-994; Summary Measures of population health: Concepts, Ethics, Measurement and Applications, WHO, 2002.) as an appropriate way of constructing summary measures of population health (SMPH) for comparative purposes. The operationalization of the VEI approach used in this paper was suggested by Nord (Summary Measures of Population Health: Concepts, Ethics, Measurement and Applications, WHO, 2002.). We test if VEI and person trade-off (PTO) methods generate similar quality-of-life weights. In addition, we compare VEI and PTO weights with individual utilities estimated by means of the conventional standard gamble (SG) and a variation of it we call double gamble. Finally, psychometric properties like feasibility, reliability, and consistency are examined. Our main findings are next: (1) VEI and PTO approaches generate very different weights; (2) it seems that differences between PTO and VEI are not due to the 'rule of rescue'; (3) the VEI resembled more a DG than a classical SG; (4) PTO, VEI, and DG exhibited good feasibility, reliability and consistency. Copyright 2004 John Wiley & Sons, Ltd.

Particle Simulation of Hypersonic Flow

DTIC Science & Technology

1990-04-24

the small volume (this is the same basic concept used in setting up Eq. (2)). Using this interpretation, we can write Eq. (11) as follows zAB dgAt = S...it leads to the expression given by ZAB dgAt = S F(g)dg P, (18) where in this case, we have S nAnB’ (19) 1 + bAB’ and where P, is again given by (17

Conversion of distiller's grain into fuel alcohol and a higher-value animal feed by dilute-acid pretreatment.

PubMed

Tucker, Melvin P; Nagle, Nicholas J; Jennings, Edward W; Ibsen, Kelly N; Aden, Andy; Nguyen, Quang A; Kim, Kyoung H; Noll, Sally L

2004-01-01

Over the past three decades ethanol production in the United States has increased more than 10-fold, to approx 2.9 billion gal/yr (mid-2003), with ethanol production expected to reach 5 billion gal/yr by 2005. The simultaneous coproduction of 7 million t/yr of distiller's grain (DG) may potentially drive down the price of DG as a cattle feed supplement. The sale of residual DG for animal feed is an important part of corn dry-grind ethanol production economics; therefore, dry-grind ethanol producers are seeking ways to improve the quality of DG to increase market penetration and help stabilize prices. One possible improvement is to increase the protein content of DG by converting the residual starch and fiber into ethanol. We have developed methods for steam explosion, SO2, and dilute-sulfuric acid pretreatment of DG for evaluation as a feedstock for ethanol production. The highest soluble sugar yields (approximately 77% of available carbohydrate) were obtained by pretreatment of DG at 140 degrees C for 20 min with 3.27 wt% H2SO4. Fermentation protocols for pretreated DG were developed at the bench scale and scaled to a working volume of 809 L for production of hydrolyzed distiller's grain (HDG) for feeding trials. The pretreated DG was fermented with Saccharomyces cerevisiae D5A, with ethanol yields of 73% of theoretical from available glucans. The HDG was air-dried and used for turkey-feeding trials. The inclusion of HDG into turkey poult (as a model non-ruminant animal) diets at 5 and 10% levels, replacing corn and soybean meal, showed weight gains in the birds similar to controls, whereas 15 and 20% inclusion levels showed slight decreases (-6%) in weight gain. At the conclusion of the trial, no negative effects on internal organs or morphology, and no mortality among the poults, was found. The high protein levels (58-61%) available in HDG show promising economics for incorporation of this process into corn dry-grind ethanol plants.

SUBFIELD AND LAYER-SPECIFIC DEPLETION IN CALBINDIN-D28K, CALRETININ AND PARVALBUMIN IMMUNOREACTIVITY IN THE DENTATE GYRUS OF APP/PS1 TRANSGENIC MICE

PubMed Central

Popovi, Miroljub; Caballero-Bleda, María; Kadish, Inga; van Groen, Thomas

2008-01-01

The depletion of neuronal calcium binding proteins deprives neurons of the capacity to buffer high levels of intracellular Ca2+ and this leaves them vulnerable to pathological processes, such as those present in Alzheimer’s disease (AD). The aim of the present study was to investigate the expression of the calcium binding proteins, calbindin-D28K, calretinin and parvalbumin in the dentate gyrus (DG) of APP/PS1 transgenic mice and their non-Tg littermates, as well as the relation with the deposition of human Aβ. We measured the expression of these three proteins at seven different rostro-caudal levels, and in the molecular, granular and polymorphic layers of the DG. We found that, except in the most caudal part of the DG, there is a substantial loss of calbindin-D28K immunoreactivity in all three layers of the DG in APP/PS1 mice compared to the non-Tg mice. Significant loss of calretinin immunoreactivity is present in most of the polymorphic layer of the DG of APP/PS1 mice compared to the non-Tg mice, as well as in the rostral and intermediate part of the inner molecular layer. Compared to the non-Tg mice parvalbumin immunoreactivity is significantly reduced throughout the whole polymorphic layer as well as in the rostral and intermediate part of the granular layer of DG in APP/PS1 mice. The relatively preservation of calbindin immunoreactivity in the caudal part of molecular and granular layers as well as calretinin immunoreactivity in the caudal part of polymorphic layer of the DG is likely related to the lower Aβ expression in those parts of DG. The present data suggest an involvement of calcium-dependent pathways in the pathogenesis of AD and indicate that there exists a subfield and layer-specific decrease in immunoreactivity which is related to the type of calcium-binding protein in APP/PS1 mice. Moreover, it seems that APP expression affects more the calbindin expression then parvalbumin and calretinin expression in the DG of APP/PS1 transgenic mice. PMID:18583063

An adaptive simplex cut-cell method for high-order discontinuous Galerkin discretizations of elliptic interface problems and conjugate heat transfer problems

NASA Astrophysics Data System (ADS)

Sun, Huafei; Darmofal, David L.

2014-12-01

In this paper we propose a new high-order solution framework for interface problems on non-interface-conforming meshes. The framework consists of a discontinuous Galerkin (DG) discretization, a simplex cut-cell technique, and an output-based adaptive scheme. We first present a DG discretization with a dual-consistent output evaluation for elliptic interface problems on interface-conforming meshes, and then extend the method to handle multi-physics interface problems, in particular conjugate heat transfer (CHT) problems. The method is then applied to non-interface-conforming meshes using a cut-cell technique, where the interface definition is completely separate from the mesh generation process. No assumption is made on the interface shape (other than Lipschitz continuity). We then equip our strategy with an output-based adaptive scheme for an accurate output prediction. Through numerical examples, we demonstrate high-order convergence for elliptic interface problems and CHT problems with both smooth and non-smooth interface shapes.

Analysis of a solar PV/battery/DG set-based hybrid system for a typical telecom load: a case study

NASA Astrophysics Data System (ADS)

Iqbal, A.; Arif, M. Saad Bin; Ayob, Shahrin Md; Siddiqui, Khursheed

2017-03-01

This paper analyses the technical and economic feasibility of using a hybrid renewable energy source for a typical telecom load in the state of Qatar. The hybrid system considered in this work consists of a solar photovoltaic with storage battery and diesel generator set. For this particular hybrid system, the meteorological data of solar irradiance in Doha city (latitude 25.15 ° North and longitude 51.33 ° East) are taken from NASA surface meteorology and solar energy websites. The solar irradiance in Doha is 5.33 kWh/m2/day on an annual average scale. The data are also taken through the study of load consumption of Qatar telecommunication hybrid power system. The system is designed and its techno-economic analysis is carried out using the Hybrid Optimization Model for Electrical Renewable software. The results show both technical and economic viability of replacing the conventional DG sets with the proposed renewable energy source.

The impact of a large penetration of intermittent sources on the power system operation and planning

NASA Astrophysics Data System (ADS)

Ausin, Juan Carlos

This research investigated the impact on the power system of a large penetration of intermittent renewable sources, mainly wind and photovoltaic generation. Currently, electrical utilities deal with wind and PV plants as if they were sources of negative demand, that is to say, they have no control over the power output produced. In this way, the grid absorbs all the power fluctuation as if it were coming from a common load. With the level of wind penetration growing so quickly, there is growing concern amongst the utilities and the grid operators, as they will have to deal with a much higher level of fluctuation. In the same way, the potential cost reduction of PV technologies suggests that a similar development may be expected for solar production in the mid term. The first part of the research was focused on the issues that affect utility planning and reinforcement decision making. Although DG is located mainly on the distribution network, a large penetration may alter the flows, not only on the distribution lines, but also on the transmission system and through the transmission - distribution interfaces. The optimal capacity and production costs for the UK transmission network have been calculated for several combinations of load profiles and typical wind/PV output scenarios. A full economic analysis is developed, showing the benefits and disadvantages that a large penetration of these distributed generators may have on transmission system operator reinforcement strategies. Closely related to planning factors are institutional, revelatory, and economic considerations, such as transmission pricing, which may hamper the integration of renewable energy technologies into the electric utility industry. The second part of the research related to the impact of intermittent renewable energy technologies on the second by second, minute by minute, and half-hour by half-hour operations of power systems. If a large integration of these new generators partially replaces the conventional rotating machines the aggregate fluctuation starts to become an important factor, and should be taken into account for the calculation of the balancing requirements. Additional balancing requirements would increase the total balancing cost and this could stop the future development of the intermittent sources.

Evaluating the Response of Polyvinyl Toluene Scintillators used in Portal Detectors

DTIC Science & Technology

2008-03-01

For the example shell script , the working directory is located at d:\\g4work. The Java development kit (jdk) is located at c:/ Java /jdk1.7.0. “JAIDA...Interval . . . . . . . . . . . . . . . . . . . . . . 64 SLAC Stanford Linear Accelerator . . . . . . . . . . . . . . . . . 84 jdk Java development...Em0, Em13, Em14 Stopping power, particle range ... Em0, Em1, Em5, Em11, Em12 Final state : energy spectra, angular distributions Em14 Energy loss

Distribution and Characterization of Antigens Found in Subcellular Fractions of African Trypanosomes

DTIC Science & Technology

1983-08-01

glycoproteln of Trypanosoma brucel synthesized with a c-termlnal hydrophob Ic tall absent from purified glycoproteln. Nature Zfifi: 624-626. 3...Cardosa de Almeida, M.L. and Turner, M.J. 1983. The membrane form of variant surface glycoprotelns of Trypanosoma brucel . Nature 202: 349- 352. 4...Blochem. 131; 1-15. 7. Godfrey, D.G. 1967. Phosphol Iplds of Trypanosoma lewlsl,. I,. vlvaxP L. congolense and L brucel . Expt. Parasit. 20

2'-Deoxyguanosine as a surrogate trapping agent for DNA reactive drug metabolites.

PubMed

Häkkinen, Merja R; Laine, Jaana E; Juvonen, Risto O; Auriola, Seppo; Häyrinen, Jukka; Pasanen, Markku

2011-11-10

Drug metabolism can result in the production of highly reactive metabolites that may form adducts with cellular macromolecules, and thus initiate adverse drug reactions, cause toxicity, and even require the withdrawal of drug from the market. In this study, a 2'-deoxyguanosine (dG)-based chemical trapping test system was developed for use as a fast screening tool for DNA adducting metabolites of new drug candidates. Reactive metabolites were generated from parent compounds in in vitro incubations with phenobarbital-induced mouse liver microsomes, human liver microsomes and different recombinant human CYP enzymes in the presence of dG. The formed dG-adducts were separated, characterized and their stability was studied by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method was evaluated with six test compounds, aflatoxin B1, estrone, clozapine, tolcapone, ticlopidine and imipramine. Estrone and aflatoxin B1 formed dG adducts with phenobarbital-induced mouse liver microsomes, human liver microsomes and human recombinant CYP enzymes. Adduct formation was also observed with tolcapone when phenobarbital-induced mouse liver microsomes were used as the enzyme source. The stability of each formed adduct was independent of the different enzyme sources. No dG-adducts were identified with ticlopidine, clozapine and imipramine. Compared to other classical DNA reactivity tests, e.g. Ames test, the present surrogate endpoint, the dG adduct, is faster, enables the characterization of the formed compounds, and also permits the investigation of more unstable adducts. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

CosmosDG: An hp -adaptive Discontinuous Galerkin Code for Hyper-resolved Relativistic MHD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anninos, Peter; Lau, Cheuk; Bryant, Colton

We have extended Cosmos++, a multidimensional unstructured adaptive mesh code for solving the covariant Newtonian and general relativistic radiation magnetohydrodynamic (MHD) equations, to accommodate both discrete finite volume and arbitrarily high-order finite element structures. The new finite element implementation, called CosmosDG, is based on a discontinuous Galerkin (DG) formulation, using both entropy-based artificial viscosity and slope limiting procedures for the regularization of shocks. High-order multistage forward Euler and strong-stability preserving Runge–Kutta time integration options complement high-order spatial discretization. We have also added flexibility in the code infrastructure allowing for both adaptive mesh and adaptive basis order refinement to be performedmore » separately or simultaneously in a local (cell-by-cell) manner. We discuss in this report the DG formulation and present tests demonstrating the robustness, accuracy, and convergence of our numerical methods applied to special and general relativistic MHD, although we note that an equivalent capability currently also exists in CosmosDG for Newtonian systems.« less

Overexpression of a novel chrysanthemum SUPERMAN-like gene in tobacco affects lateral bud outgrowth and flower organ development.

PubMed

Liu, Qing-Lin; Xu, Ke-Dong; Ma, Nan; Zhao, Liang-Jun; Xi, Lin

2014-04-01

Previous studies have shown that the SUP genes play important roles in flower development and plant growth and morphogenesis. In this study, we isolated and characterized a SUPERMAN-like gene DgSZFP from chrysanthemum. DgSZFP contains one conserved Cys2/His2-type zinc finger motifs in the N-terminal region and an EAR-box in C-terminus. Its expression was significantly higher in nodes, flower buds, disc stamens, and petals than in the other tissues. Overexpression of DgSZFP in tobacco resulted in enhanced branching, reduced plant height, increased the width of petal tubes, produced the staminoid petals and petaloid stamens in flowers, and enhanced the seed weight and size. In addition, DgSZFP-overexpression tobacco plants accumulated high concentrations of cytokinin and chlorophyll. These results suggest that DgSZFP may be the candidate gene for regulating branching and floral organ development in chrysanthemum. Crown Copyright © 2014. Published by Elsevier Masson SAS. All rights reserved.

CosmosDG: An hp-adaptive Discontinuous Galerkin Code for Hyper-resolved Relativistic MHD

NASA Astrophysics Data System (ADS)

Anninos, Peter; Bryant, Colton; Fragile, P. Chris; Holgado, A. Miguel; Lau, Cheuk; Nemergut, Daniel

2017-08-01

We have extended Cosmos++, a multidimensional unstructured adaptive mesh code for solving the covariant Newtonian and general relativistic radiation magnetohydrodynamic (MHD) equations, to accommodate both discrete finite volume and arbitrarily high-order finite element structures. The new finite element implementation, called CosmosDG, is based on a discontinuous Galerkin (DG) formulation, using both entropy-based artificial viscosity and slope limiting procedures for the regularization of shocks. High-order multistage forward Euler and strong-stability preserving Runge-Kutta time integration options complement high-order spatial discretization. We have also added flexibility in the code infrastructure allowing for both adaptive mesh and adaptive basis order refinement to be performed separately or simultaneously in a local (cell-by-cell) manner. We discuss in this report the DG formulation and present tests demonstrating the robustness, accuracy, and convergence of our numerical methods applied to special and general relativistic MHD, although we note that an equivalent capability currently also exists in CosmosDG for Newtonian systems.

Long-term Optical Activity of the Hard X-ray Flaring Star DG CVn

NASA Astrophysics Data System (ADS)

Šimon, V.

2017-04-01

DG CVn is a young late-type star which displayed an X-ray and optical superflare in 2014. This paper presents an analysis of the long-term activity of this object in the optical band. I used the photographic data from DASCH (Digital Access to a Sky Century @ Harvard). These measurements from the years 1895-1989 cover the blue spectral region. CCD V-band ASAS data were used for several UV Cet-type stars to place the activity of DG CVn in the context of flaring stars. I show that three large brightenings (flares) of DG CVn by more than 1 mag were detected on the DASCH plates. The character of the long-term activity (regarding the histogram of brightness) of DG CVn is compatible with those of flaring stars UV Cet and V371 Ori. The flares brighter than ˜ 0.4 mag represent less than 1 percent of the observed data in all three objects

Characterization of the P. Brevis Polyether Neurotoxin Binding Component in Excitable Membranes

DTIC Science & Technology

1991-09-14

International Conference on Ciguatera . (T. R. Tosteson and D. Ballantyne, Eds.) in press. Baden, D.G. (1991) The Polyether Brevetoxins and Site Five of the...Confomrations and Potency Correlations. Third Intl. Conf. Ciguatera , Puerto Rico 1990. Tosteson, T.R., and Baden, D.G. Polyether Dinoflagellate Toxins...and Caribbean Ciguatera : Correlation of Fish Toxins with Standard Toxins Third International Conference on Ciguatera , Peurto Rico 1990. Baden, D.G

Analysis of the Central X-ray Source in DG Tau

NASA Astrophysics Data System (ADS)

Schneider, P. Christian; Schmitt, Jürgen H. M. M.

As a stellar X-ray source DG Tau shows two rather unusual features: A resolved X-ray jet [2] and an X-ray spectrum best described by two thermal components with different absorbing column densities, a so called "two-absorber X-ray (TAX)" morphology [1, 2]. In an effort to understand the properties of the central X-ray source in DG Tau a detailed position analysis was carried out.

Acute moderate exercise improves mnemonic discrimination in young adults.

PubMed

Suwabe, Kazuya; Hyodo, Kazuki; Byun, Kyeongho; Ochi, Genta; Yassa, Michael A; Soya, Hideaki

2017-03-01

Increasing evidence suggests that regular moderate exercise increases neurogenesis in the dentate gyrus (DG) of the hippocampus and improves memory functions in both humans and animals. The DG is known to play a role in pattern separation, which is the ability to discriminate among similar experiences, a fundamental component of episodic memory. While long-term voluntary exercise improves pattern separation, there is little evidence of alterations in DG function after an acute exercise session. Our previous studies showing acute moderate exercise-enhanced DG activation in rats, and acute moderate exercise-enhanced prefrontal activation and executive function in humans, led us to postulate that acute moderate exercise may also activate the hippocampus, including more specifically the DG, thus improving pattern separation. We thus investigated the effects of a 10-min moderate exercise (50% V̇O 2peak ) session, the recommended intensity for health promotion, on mnemonic discrimination (a behavioral index of pattern separation) in young adults. An acute bout of moderate exercise improved mnemonic discrimination performance in high similarity lures. These results support our hypothesis that acute moderate exercise improves DG-mediated pattern separation in humans, proposing a useful human acute-exercise model for analyzing the neuronal substrate underlying acute and regular exercise-enhanced episodic memory based on the hippocampus. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Acute Moderate Exercise Improves Mnemonic Discrimination in Young Adults

PubMed Central

Suwabe, Kazuya; Hyodo, Kazuki; Byun, Kyeongho; Ochi, Genta; Yassa, Michael A.; Soya, Hideaki

2018-01-01

Increasing evidence suggests that regular moderate exercise increases neurogenesis in the dentate gyrus (DG) of the hippocampus and improves memory functions in both humans and animals. The DG is known to play a role in pattern separation, which is the ability to discriminate among similar experiences, a fundamental component of episodic memory. While long-term voluntary exercise improves pattern separation, there is little evidence of alterations in DG function after an acute exercise session. Our previous studies showing acute moderate exercise-enhanced DG activation in rats, and acute moderate exercise-enhanced prefrontal activation and executive function in humans, led us to postulate that acute moderate exercise may also activate the hippocampus, including more specifically the DG, thus improving pattern separation. We thus investigated the effects of a 10-min moderate exercise (50% V̇O2peak) session, the recommended intensity for health promotion, on mnemonic discrimination (a behavioral index of pattern separation) in young adults. An acute bout of moderate exercise improved mnemonic discrimination performance in high similarity lures. These results support our hypothesis that acute moderate exercise improves DG-mediated pattern separation in humans, proposing a useful human acute-exercise model for analyzing the neuronal substrate underlying acute and regular exercise-enhanced episodic memory based on the hippocampus. PMID:27997992

Robust and Accurate Shock Capturing Method for High-Order Discontinuous Galerkin Methods

NASA Technical Reports Server (NTRS)

Atkins, Harold L.; Pampell, Alyssa

2011-01-01

A simple yet robust and accurate approach for capturing shock waves using a high-order discontinuous Galerkin (DG) method is presented. The method uses the physical viscous terms of the Navier-Stokes equations as suggested by others; however, the proposed formulation of the numerical viscosity is continuous and compact by construction, and does not require the solution of an auxiliary diffusion equation. This work also presents two analyses that guided the formulation of the numerical viscosity and certain aspects of the DG implementation. A local eigenvalue analysis of the DG discretization applied to a shock containing element is used to evaluate the robustness of several Riemann flux functions, and to evaluate algorithm choices that exist within the underlying DG discretization. A second analysis examines exact solutions to the DG discretization in a shock containing element, and identifies a "model" instability that will inevitably arise when solving the Euler equations using the DG method. This analysis identifies the minimum viscosity required for stability. The shock capturing method is demonstrated for high-speed flow over an inviscid cylinder and for an unsteady disturbance in a hypersonic boundary layer. Numerical tests are presented that evaluate several aspects of the shock detection terms. The sensitivity of the results to model parameters is examined with grid and order refinement studies.

The Flexible Solar Utility. Preparing for Solar's Impacts to Utility Planning and Operations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sterling, John; Davidovich, Ted; Cory, Karlynn

2015-09-01

This paper seeks to provide a flexible utility roadmap for identifying the steps that need to be taken to place the utility in the best position for addressing solar in the future. Solar growth and the emergence of new technologies will change the electric utility of tomorrow. Although not every utility, region, or market will change in the same way or magnitude, developing a path forward will be needed to reach the Electric System of the Future in the coming decades. In this report, a series of potential future states are identified that could result in drastically different energy mixesmore » and profiles: 1) Business as Usual, 2) Low Carbon, Centralized Generation, 3) Rapid Distributed Energy Resource Growth, 4) Interactivity of Both the Grid and Demand, and 5) Grid or Load Defection. Complicating this process are a series of emerging disruptions; decisions or events that will cause the electric sector to change. Understanding and preparing for these items is critical for the transformation to any of the future states to be successful. Predicting which future state will predominate 15 years from now is not possible; however, utilities still will need to look ahead and try to anticipate how factors will impact their planning, operations, and business models. In order to dig into the potential transformations facing the utility industry, the authors conducted a series of utility interviews, held a working session at a major industry solar conference, and conducted a quantitative survey. To focus conversations, the authors leveraged the Rapid Distributed Energy Resource (DER) Growth future to draw out how utilities would have to adapt from current processes and procedures in order to manage and thrive in that new environment. Distributed solar was investigated specifically, and could serve as a proxy resource for all distributed generation (DG). It can also provide the foundation for all DERs.« less

Doppler-Guided Transanal Hemorrhoidal Dearterialization (DG-THD) Versus Stapled Hemorrhoidopexy (SH) in the Treatment of Third-Degree Hemorrhoids: Clinical Results at Short and Long-Term Follow-Up.

PubMed

Leardi, S; Pessia, B; Mascio, M; Piccione, F; Schietroma, M; Pietroletti, R

2016-11-01

The stapled hemorrhoidopexy (SH) and the Doppler-guided transanal hemorrhoidal dearterialization (DG-THD) are minimally invasive procedures for the surgical treatment of hemorrhoids. This study aims to verify the efficacy of the DG-THD versus the SH in the treatment of third-degree hemorrhoids. One hundred consecutive patients were causally allocated to either procedure, obtaining two groups of 50 pts. A clinical examination was performed at 3, 7, 15, and 30 days after the operation. Quality of life, anal symptoms, recurrence of hemorrhoids, and reoperation were assessed by means of a questionnaire and of a clinical examination at long-term follow-up (7.0 year average). At short-term follow-up, the median postoperative pain score was significantly lower in DG-THD group compared to SH group, (V.A.S 2 vs 6; t = 2.65, p < 0.01). The morbidity rate and the return to normal life and work were similar after the two procedures. At long-term follow-up, the incidence of piles was not statistically different between the two groups (DG-THD 10.0 %; SH 14.0 %). No differences were reported by patients in terms of satisfaction for surgery. SH and DG-THD procedures do not show significantly different results with regard to the patients outcome. However, considering the lower p. o. pain, the DG-THD might be proposed as the first line treatment in third-degree hemorrhoids.

Functional recovery of the dentate gyrus after a focal lesion is accompanied by structural reorganization in the adult rat.

PubMed

Zepeda, Angélica; Aguilar-Arredondo, Andrea; Michel, Gabriela; Ramos-Languren, Laura Elisa; Escobar, Martha L; Arias, Clorinda

2013-03-01

The adult brain is highly plastic and tends to undergo substantial reorganization after injury to compensate for the lesion effects. It has been shown that such reorganization mainly relies on anatomical and biochemical modifications of the remaining cells which give rise to a network rewiring without reinstating the original morphology of the damaged region. However, few studies have analyzed the neurorepair potential of a neurogenic structure. Thus, the aim of this work was to analyze if the DG could restore its original morphology after a lesion and to establish if the structural reorganization is accompanied by behavioral and electrophysiological recovery. Using a subepileptogenic injection of kainic acid (KA), we induced a focal lesion in the DG and assessed in time (1) the loss and recovery of dependent and non dependent DG cognitive functions, (2) the anatomical reorganization of the DG using a stereological probe and immunohistochemical markers for different neuronal maturation stages and, (3) synaptic plasticity as assessed through the induction of in vivo long-term potentiation (LTP) in the mossy fiber pathway (CA3-DG). Our results show that a DG focal lesion with KA leads to a well delimited region of neuronal loss, disorganization of the structure, the loss of associated mnemonic functions and the impairment to elicit LTP. However, behavioral and synaptic plasticity expression occurs in a time dependent fashion and occurs along the morphological restoration of the DG. These results provide novel information on neural plasticity events associated to functional reorganization after damage.

Temporal associations for spatial events: the role of the dentate gyrus.

PubMed

Morris, Andrea M; Curtis, Brian J; Churchwell, John C; Maasberg, David W; Kesner, Raymond P

2013-11-01

Previous research suggests that the dorsal dentate gyrus (DG) hippocampal subregion mediates spatial processing functions. However, a novel role for the DG in temporal processing for spatial information has begun to emerge based on the development of a computational model of neurogenesis. According to this model, adult born granule cells in the DG contribute to a temporal associative integration process for events presented closer in time. Currently, there is a paucity of behavioral evidence to support the temporal integration theory. Therefore, we developed a novel behavioral paradigm to investigate the role of the dDG in temporal integration for proximal and distal spatial events. Male Long-Evans rats were randomly assigned to a control group or to receive bilateral intracranial infusions of colchicine into the dDG. Following recovery from surgery, each rat was tested on a cued-recall of sequence paradigm. In this task, animals were allowed to explore identical objects placed in designated spatial locations on a cheeseboard maze across 2 days (e.g., Day 1: A and B; Day 2: C and D). One week later, animals were given a brief cue (A or C) followed by a preference test between spatial location B and D. Control animals had a significant preference for the spatial location previously paired with the cue (the temporal associate) whereas dDG lesioned animals failed to show a preference. These findings suggest that selective colchicine-induced dDG lesions are capable of disrupting the formation of temporal associations between spatial events presented close in time. Copyright © 2013 Elsevier B.V. All rights reserved.

Aromatic aldehydes at the active site of aldehyde oxidoreductase from Desulfovibrio gigas: reactivity and molecular details of the enzyme-substrate and enzyme-product interaction.

PubMed

Correia, Hugo D; Marangon, Jacopo; Brondino, Carlos D; Moura, Jose J G; Romão, Maria J; González, Pablo J; Santos-Silva, Teresa

2015-03-01

Desulfovibrio gigas aldehyde oxidoreductase (DgAOR) is a mononuclear molybdenum-containing enzyme from the xanthine oxidase (XO) family, a group of enzymes capable of catalyzing the oxidative hydroxylation of aldehydes and heterocyclic compounds. The kinetic studies reported in this work showed that DgAOR catalyzes the oxidative hydroxylation of aromatic aldehydes, but not heterocyclic compounds. NMR spectroscopy studies using (13)C-labeled benzaldehyde confirmed that DgAOR catalyzes the conversion of aldehydes to the respective carboxylic acids. Steady-state kinetics in solution showed that high concentrations of the aromatic aldehydes produce substrate inhibition and in the case of 3-phenyl propionaldehyde a suicide substrate behavior. Hydroxyl-substituted aromatic aldehydes present none of these behaviors but the kinetic parameters are largely affected by the position of the OH group. High-resolution crystallographic structures obtained from single crystals of active-DgAOR soaked with benzaldehyde showed that the side chains of Phe425 and Tyr535 are important for the stabilization of the substrate in the active site. On the other hand, the X-ray data of DgAOR soaked with trans-cinnamaldehyde showed a cinnamic acid molecule in the substrate channel. The X-ray data of DgAOR soaked with 3-phenyl propionaldehyde showed clearly how high substrate concentrations inactivate the enzyme by binding covalently at the surface of the enzyme and blocking the substrate channel. The different reactivity of DgAOR versus aldehyde oxidase and XO towards aromatic aldehydes and N-heterocyclic compounds is explained on the basis of the present kinetic and structural data.

Background and stimulus-induced patterns of high metabolic activity in the visual cortex (area 17) of the squirrel and macaque monkey

DOE Office of Scientific and Technical Information (OSTI.GOV)

Humphrey, A.L.; Hendrickson, A.E.

1983-02-01

We have used 2-deoxy-D-(/sup 14/C)glucose (2-DG) autoradiography and cytochrome oxidase histochemistry to examine background and stimulus-induced patterns of metabolic activity in monkey striate cortex. In squirrel monkeys (Saimiri sciureus) that binocularly or monocularly viewed diffuse white light or binocularly viewed bars of many orientations and spatial frequencies, 2-DG consumption was not uniform across the cortex but consisted of regularly spaced radial zones of high uptake. The zones extended through all laminae except IVc beta and, when viewed tangentially, formed separate patches 500 microns apart. The cytochrome oxidase stain in these animals also revealed patches of high metabolism which coincided withmore » the 2-DG patches. Squirrel monkeys binocularly viewing vertical stripes showed parallel bands of increased 2-DG uptake in the cortex, while the cytochrome label in these animals remained patchy. When monkeys were kept in the dark during 2-DG exposure, 2-DG-labeled patches were not seen but cytochrome oxidase-positive patches remained. In macaque (Macaca nemestrina) monkeys, binocular stimulation with many orientations and spatial frequencies produced radial zones of high 2-DG uptake in layers I to IVa and VI. When viewed tangentially, these zones formed a dots-in-rows pattern with a spacing of 350 X 500 microns; cytochrome oxidase staining produced an identical pattern. Macaca differed from Saimiri in that monocular stimulation labeled alternate rows. These results indicate that there are radial zones of high background metabolism across squirrel and macaque monkey striate cortex. In Saimiri these zones do not appear to be related to an eye dominance system, while in Macaca they do. The presence of these zones of high metabolism may complicate the interpretation of 2-DG autoradiographs that result from specific visual stimuli.« less

Evaluation of Selected Nutrients and Contaminants in Distillers Grains from Ethanol Production in Texas.

PubMed

Lee, Kyung-Min; Herrman, Timothy J; Post, Lynn

2016-09-01

This article contains the results of the evaluation of distillers grain (DG) coproducts from different ethanol plants around the United States and supplemented in animal diets in Texas, based on samples analyzed from 2008 to 2014. The samples were assessed for concentration, occurrence, and prevalence of selected nutrients and contaminants. Protein and sulfur contents of DG were largely different between maize and sorghum coproducts, as well as wet distillers grain with solubles (WDGS) and dried distillers grain with solubles (DDGS), indicating a significant effect of grain feedstock and dry grind process stream on DG composition and quality. Salmonella was isolated in 4 DDGS samples of a total of 157 DG samples, a percentage (2.5%) that is lower than the percentage of Salmonella -positive samples found in other feed samples analyzed during the same period. A small amount of virginiamycin residue was found in 24 maize DDGS, 1 maize WDGS, and 2 sorghum DDGS samples of 242 samples in total. One sorghum DDGS sample of 168 DG samples was contaminated with animal protein prohibited for use in ruminant feed and was channeled to poultry feed. The concentrations of aflatoxin and fumonisin DG coproducts averaged 3.4 μg/kg and 0.7 mg/kg, respectively. Among contaminated maize DG samples, five DDGS samples for aflatoxin contained a higher concentration than the U.S. Food and Drug Administration (FDA) minimum action level of 20 μg/kg for use in animal feed, whereas no sample for fumonisin was found above the action level of 5 mg/kg. The study provides the most current results involving DG coproducts and associated hazards that will assist development of food safety plans required by the FDA in their September 2015 rule titled "Current Good Manufacturing Practice Hazard Analysis and Risk Based Preventive Controls for Food for Animals."

The Effect of Local Delivery Doxycycline and Alendronate on Bone Repair.

PubMed

Limirio, Pedro Henrique Justino Oliveira; Rocha, Flaviana Soares; Batista, Jonas Dantas; Guimarães-Henriques, João César; de Melo, Geraldo Batista; Dechichi, Paula

2016-08-01

The aim of the present study was to investigate the local effect of 10% doxycycline and 1% alendronate combined with poly(lactic-co-glycolic acid) (PLGA) on bone repair. Thirty rats were divided into three groups, as follows: control group (CG), drug group (DG), and vehicle-PLGA group (VG). Bone defect was created in the right femur and filled with the following: blood clot (CG); PLGA gel, 10% doxycycline and 1% alendronate (DG); or vehicle-PLGA (VG). The animals were euthanized 7 or 15 days after surgery. Bone density, bone matrix and number of osteoclasts were quantified. At 7 days, the findings showed increased density in DG (177.75 ± 76.5) compared with CG (80.37 ± 27.4), but no difference compared with VG (147.1 ± 41.5); no statistical difference in bone neoformation CG (25.6 ± 4.8), VG (27.8 ± 4), and DG (18.9 ± 7.8); and decrease osteoclasts in DG (4.6 ± 1.9) compared with CG (26.7 ± 7.4) and VG (17.3 ± 2.7). At 15 days, DG (405.1 ± 63.1) presented higher density than CG (213.2 ± 60.9) and VG (283.4 ± 85.8); there was a significant increase in percentage of bone neoformation in DG (31.5 ± 4.2) compared with CG (23 ± 4), but no difference compared with VG (25.1 ± 2.9). There was a decreased number of osteoclasts in DG (20.7 ± 4.7) and VG (29.5 ± 5.4) compared with CG (40 ± 9.4). The results suggest that the association of 10% doxycycline and 1% alendronate with PLGA-accelerated bone repair.

Mechanistic Basis for the Bypass of a Bulky DNA Adduct Catalyzed by a Y-Family DNA Polymerase

PubMed Central

Vyas, Rajan; Efthimiopoulos, Georgia; Tokarsky, E. John; Malik, Chanchal K.; Basu, Ashis K.; Suo, Zucai

2015-01-01

1-Nitropyrene (1-NP), an environmental pollutant, induces DNA damage in vivo and is considered to be carcinogenic. The DNA adducts formed by the 1-NP metabolites stall replicative DNA polymerases but are presumably bypassed by error-prone Y-family DNA polymerases at the expense of replication fidelity and efficiency in vivo. Our running start assays confirmed that a site-specifically placed 8-(deoxyguanosin-N2-yl)-1-aminopyrene (dG1,8), one of the DNA adducts derived from 1-NP, can be bypassed by Sulfolobus solfataricus DNA polymerase IV (Dpo4), although this representative Y-family enzyme was paused strongly by the lesion. Pre-steady-state kinetic assays were employed to determine the low nucleotide incorporation fidelity and establish a minimal kinetic mechanism for the dG1,8 bypass by Dpo4. To reveal a structural basis for dCTP incorporation opposite dG1,8, we solved the crystal structures of the complexes of Dpo4 and DNA containing a templating dG1,8 lesion in the absence or presence of dCTP. The Dpo4·DNA-dG1,8 binary structure shows that the aminopyrene moiety of the lesion stacks against the primer/template junction pair, while its dG moiety projected into the cleft between the Finger and Little Finger domains of Dpo4. In the Dpo4·DNA-dG1,8·dCTP ternary structure, the aminopyrene moiety of the dG1,8 lesion, is sandwiched between the nascent and junction base pairs, while its base is present in the major groove. Moreover, dCTP forms a Watson–Crick base pair with dG, two nucleotides upstream from the dG1,8 site, creating a complex for “-2” frameshift mutation. Mechanistically, these crystal structures provide additional insight into the aforementioned minimal kinetic mechanism. PMID:26327169

The immature dentate gyrus represents a shared phenotype of mouse models of epilepsy and psychiatric disease

PubMed Central

Shin, Rick; Kobayashi, Katsunori; Hagihara, Hideo; Kogan, Jeffrey H; Miyake, Shinichi; Tajinda, Katsunori; Walton, Noah M; Gross, Adam K; Heusner, Carrie L; Chen, Qian; Tamura, Kouichi; Miyakawa, Tsuyoshi; Matsumoto, Mitsuyuki

2013-01-01

Objectives There is accumulating evidence to suggest psychiatric disorders, such as bipolar disorder and schizophrenia, share common etiologies, pathophysiologies, genetics, and drug responses with many of the epilepsies. Here, we explored overlaps in cellular/molecular, electrophysiological, and behavioral phenotypes between putative mouse models of bipolar disorder/schizophrenia and epilepsy. We tested the hypothesis that an immature dentate gyrus (iDG), whose association with psychosis in patients has recently been reported, represents a common phenotype of both diseases. Methods Behaviors of calcium/calmodulin-dependent protein kinase II alpha (α-CaMKII) heterozygous knock-out (KO) mice, which are a representative bipolar disorder/schizophrenia model displaying iDG, and pilocarpine-treated mice, which are a representative epilepsy model, were tested followed by quantitative polymerase chain reaction (qPCR)/immunohistochemistry for mRNA/protein expression associated with an iDG phenotype. In vitro electrophysiology of dentate gyrus granule cells (DG GCs) was examined in pilocarpine-treated epileptic mice. Results The two disease models demonstrated similar behavioral deficits, such as hyperactivity, poor working memory performance, and social withdrawal. Significant reductions in mRNA expression and immunoreactivity of the mature neuronal marker calbindin and concomitant increases in mRNA expression and immunoreactivity of the immature neuronal marker calretinin represent iDG signatures that are present in both mice models. Electrophysiologically, we have confirmed that DG GCs from pilocarpine-treated mice represent an immature state. A significant decrease in hippocampal α-CaMKII protein levels was also found in both models. Conclusions Our data have shown iDG signatures from mouse models of both bipolar disorder/schizophrenia and epilepsy. The evidence suggests that the iDG may, in part, be responsible for the abnormal behavioral phenotype, and that the underlying pathophysiologies in epilepsy and bipolar disorder/schizophrenia are strikingly similar. PMID:23560889

The immature dentate gyrus represents a shared phenotype of mouse models of epilepsy and psychiatric disease.

PubMed

Shin, Rick; Kobayashi, Katsunori; Hagihara, Hideo; Kogan, Jeffrey H; Miyake, Shinichi; Tajinda, Katsunori; Walton, Noah M; Gross, Adam K; Heusner, Carrie L; Chen, Qian; Tamura, Kouichi; Miyakawa, Tsuyoshi; Matsumoto, Mitsuyuki

2013-06-01

There is accumulating evidence to suggest psychiatric disorders, such as bipolar disorder and schizophrenia, share common etiologies, pathophysiologies, genetics, and drug responses with many of the epilepsies. Here, we explored overlaps in cellular/molecular, electrophysiological, and behavioral phenotypes between putative mouse models of bipolar disorder/schizophrenia and epilepsy. We tested the hypothesis that an immature dentate gyrus (iDG), whose association with psychosis in patients has recently been reported, represents a common phenotype of both diseases. Behaviors of calcium/calmodulin-dependent protein kinase II alpha (α-CaMKII) heterozygous knock-out (KO) mice, which are a representative bipolar disorder/schizophrenia model displaying iDG, and pilocarpine-treated mice, which are a representative epilepsy model, were tested followed by quantitative polymerase chain reaction (qPCR)/immunohistochemistry for mRNA/protein expression associated with an iDG phenotype. In vitro electrophysiology of dentate gyrus granule cells (DG GCs) was examined in pilocarpine-treated epileptic mice. The two disease models demonstrated similar behavioral deficits, such as hyperactivity, poor working memory performance, and social withdrawal. Significant reductions in mRNA expression and immunoreactivity of the mature neuronal marker calbindin and concomitant increases in mRNA expression and immunoreactivity of the immature neuronal marker calretinin represent iDG signatures that are present in both mice models. Electrophysiologically, we have confirmed that DG GCs from pilocarpine-treated mice represent an immature state. A significant decrease in hippocampal α-CaMKII protein levels was also found in both models. Our data have shown iDG signatures from mouse models of both bipolar disorder/schizophrenia and epilepsy. The evidence suggests that the iDG may, in part, be responsible for the abnormal behavioral phenotype, and that the underlying pathophysiologies in epilepsy and bipolar disorder/schizophrenia are strikingly similar. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Characterization of the Pathological and Biochemical Markers that Correlate to the Clinical Features of Autism

DTIC Science & Technology

2012-08-01

system in relation to its evolution, structure and function . New York: CRC Press 1997 American Psychiatric Association. Diagnostic and statistical...Hesslow G, Yeo CH. The functional anatomy of skeletal conditioning. In: Moore JW, Editor. A neuroscientist’s guide to classical conditioning. New ...1995; Selkoe, 2001). Aβ is generated and detected in the endoplasmic reticulum/ Golgi apparatus and endosomal-lysosomal pathway (Cook D.G. et al., 1997

Evaluation of Commercially Available Cyanide Test Kits against Various Matrices

DTIC Science & Technology

2016-08-01

further evaluation in a second phase of testing. Cyantesmo paper was tested against 15 matrices, including baking soda, boric acid, brewer’s yeast...matrices were baking soda, boric acid, brewer’s yeast, chalk dust, chitin, coffee powder (instant coffee), cornstarch, drywall dust, flour, kaolin...TN);  DG powdered sugar;  DG talcum powder (Lot 14312THW);  DG Clover Valley baking soda (Lot PMHB51);  Boric acid (Lot 766965; Fisher

Disconnection Analysis of CA3 and DG in Mediating Encoding but Not Retrieval in a Spatial Maze Learning Task

ERIC Educational Resources Information Center

Jerman, Taylor; Kesner, Raymond P.; Hunsaker, Michael R.

2006-01-01

The dentate gyrus (DG) subregion of the hippocampus has been shown to be involved in encoding but not retrieval in a spatial maze task (modified Hebb-Williams maze). The first experiment in this study examined whether a lesion to the CA3 would contribute to a similar encoding deficit. A DG group was included in order to replicate previous results.…

Expression pattern in retinal photoreceptors of POMGnT1, a protein involved in muscle-eye-brain disease

PubMed Central

Uribe, Mary Luz; Haro, Carmen; Campello, Laura; Cruces, Jesús; Martín-Nieto, José

2016-01-01

Purpose The POMGNT1 gene, encoding protein O-linked-mannose β-1,2-N-acetylglucosaminyltransferase 1, is associated with muscle-eye-brain disease (MEB) and other dystroglycanopathies. This gene’s lack of function or expression causes hypoglycosylation of α-dystroglycan (α-DG) in the muscle and the central nervous system, including the brain and the retina. The ocular symptoms of patients with MEB include retinal degeneration and detachment, glaucoma, and abnormal electroretinogram. Nevertheless, the POMGnT1 expression pattern in the healthy mammalian retina has not yet been investigated. In this work, we address the expression of the POMGNT1 gene in the healthy retina of a variety of mammals and characterize the distribution pattern of this gene in the adult mouse retina and the 661W photoreceptor cell line. Methods Using reverse transcription (RT)–PCR and immunoblotting, we studied POMGNT1 expression at the mRNA and protein levels in various mammalian species, from rodents to humans. Immunofluorescence confocal microscopy analyses were performed to characterize the distribution profile of its protein product in mouse retinal sections and in 661W cultured cells. The intranuclear distribution of POMT1 and POMT2, the two enzymes preceding POMGnT1 in the α-DG O-mannosyl glycosylation pathway, was also analyzed. Results POMGNT1 mRNA and its encoded protein were expressed in the neural retina of all mammals studied. POMGnT1 was located in the cytoplasmic fraction in the mouse retina and concentrated in the myoid portion of the photoreceptor inner segments, where the protein colocalized with GM130, a Golgi complex marker. The presence of POMGnT1 in the Golgi complex was also evident in 661W cells. However, and in contrast to retinal tissue, POMGnT1 additionally accumulated in the nucleus of the 661W photoreceptors. Colocalization was found within this organelle between POMGnT1 and POMT1/2, the latter associated with euchromatic regions of the nucleus. Conclusions Our results indicate that POMGnT1 participates not only in the synthesis of O-mannosyl glycans added to α-DG in the Golgi complex but also in the glycosylation of other yet-to-be-identified proteins in the nucleus of mouse photoreceptors. PMID:27375352

Metallicity Effects on Stellar Magnetic Activity: Blanco 1 as a Test Case

NASA Technical Reports Server (NTRS)

Harnden, F. R., Jr.; Mushotzky, Richard F. (Technical Monitor)

2003-01-01

We present X-ray Luminosity Distributions (XLDs) of late-type members (dF, dG, dK, dM) of the Blanco 1 cluster, based on ROSAT-HRI data and new astrometric-photometric membership obtained from the GSC-II project. For the first time we present the XLD of dM stars of this cluster. The high metallicity of Blanco 1 allows us to investigate the role of chemical composition on the coronal emission of late-type stars. Comparison between X-ray Luminosity Distributions of Blanco 1 and Pleiades, NGC2516 and alpha Per suggests a possible metallicity effect in dM stars.

Separate and concurrent use of 2-deoxy-D-glucose and 3-bromopyruvate in pancreatic cancer cells.

PubMed

Xiao, Huijie; Li, Shasha; Zhang, Dapeng; Liu, Tongjun; Yu, Ming; Wang, Feng

2013-01-01

Unrestrained glycolysis characterizes energy meta-bolism in cancer cells. Thus, antiglycolytic reagents such as 2-deoxy-D-glucose (2-DG) and 3-bromopyruvate (3-BrPA) may be used as anticancer drugs. In the present study, we examined the anticancer effects of 2-DG and 3-BrPA in pancreatic cancer cells and investigated whether these effects were regulated by hypoxia-inducible factor-1α (HIF-1α). To this end, 2-DG and 3-BrPA were administered to wild-type (wt) MiaPaCa2 and Panc-1 pancreatic cancer cells that were incubated under hypoxic (HIF-1α-positive) or normoxic (HIF-1α-negative) conditions. In addition, 2-DG and 3-BrPA were also administered to si-MiaPaCa2 and si-Panc-1 cells that lacked HIF-1α as a result of RNA interference. Following drug exposure, cell population was measured using a viability assay. Both HIF-1α-positive and HIF-1α-negative MiaPaCa2 cells were further studied for their expression of Cu/Zn-superoxide dismutase (SOD1) and poly(ADP-ribose) polymerase (PARP) and for their contents of ATP and fumarate. In the viability assay, either 2-DG or 3-BrPA decreased the tested cells. Concurrent use of 2-DG and 3-BrPA resulted in a greater decrease of cells and also facilitated ATP depletion. In addition, 3-BrPA was seen to both decrease SOD1 and increase fumarate, which suggests that the reagent impaired the mitochondria. 3-BrPA also decreased both full-length PARP and cleaved PARP, which suggests that 3-BrPA-induced decrease in cell population was a result of cell necrosis rather than apoptosis. When HIF-1α was induced in wt-MiaPaCa2 cells by hypoxia, some effects of 2-DG and 3-BrPA were attenuated. We conclude that: i) concurrent use of 2-DG and 3-BrPA has better anticancer effects in pancreatic cancer cells, ii) 3-BrPA impairs the mitochondria of pancreatic cancer cells and induces cell necrosis, and iii) HIF-1α regulates the anticancer effects of 2-DG and 3-BrPA in pancreatic cancer cells.

Do not play God: contrasting effects of deontological guilt and pride on decision-making

PubMed Central

Mancini, Alessandra; Mancini, Francesco

2015-01-01

Recent accounts support the existence of two distinct feelings of guilt: altruistic guilt (AG), arising from the appraisal of not having been altruistic toward a victim and deontological guilt (DG), emerging from the appraisal of having violated an intuitive moral rule. Neuroimaging data has shown that the two guilt feelings trigger different neural networks, with DG selectively activating the insula, a brain area involved in the processing of disgust and self-reproach. Thus, insula activation could reflect the major involvement of self-reproach in DG rather than in AG. However, only a few studies have empirically tested whether and how DG and AG differently affect decision making and none have compared enhanced self-worth. Here we asked three groups of participants, respectively, induced with either pride, DG or AG, to participate in a third-party version of the ultimatum game in which they were asked to decide on behalf of others to accept or reject economic offers with several degrees of fairness. Results revealed that only deontological participants had higher median acceptances of Moderately Unfair offers as compared to proud participants. However fairness judgments were not different between groups, suggesting that deontological participants’ moral standards had not decreased. Crucially, a higher increase in DG was associated with an increase in the odds of accepting 30:70 offers. The opposite effects that DG and pride exert on self-worth can account for these results. Specifically, proud participants felt entitled enough to take action in order to restore equity, while deontological participants followed the “Do not play God” principle, which limited their decisional autonomy, not allowing them to decide on behalf of others. PMID:26379584

Do not play God: contrasting effects of deontological guilt and pride on decision-making.

PubMed

Mancini, Alessandra; Mancini, Francesco

2015-01-01

Recent accounts support the existence of two distinct feelings of guilt: altruistic guilt (AG), arising from the appraisal of not having been altruistic toward a victim and deontological guilt (DG), emerging from the appraisal of having violated an intuitive moral rule. Neuroimaging data has shown that the two guilt feelings trigger different neural networks, with DG selectively activating the insula, a brain area involved in the processing of disgust and self-reproach. Thus, insula activation could reflect the major involvement of self-reproach in DG rather than in AG. However, only a few studies have empirically tested whether and how DG and AG differently affect decision making and none have compared enhanced self-worth. Here we asked three groups of participants, respectively, induced with either pride, DG or AG, to participate in a third-party version of the ultimatum game in which they were asked to decide on behalf of others to accept or reject economic offers with several degrees of fairness. Results revealed that only deontological participants had higher median acceptances of Moderately Unfair offers as compared to proud participants. However fairness judgments were not different between groups, suggesting that deontological participants' moral standards had not decreased. Crucially, a higher increase in DG was associated with an increase in the odds of accepting 30:70 offers. The opposite effects that DG and pride exert on self-worth can account for these results. Specifically, proud participants felt entitled enough to take action in order to restore equity, while deontological participants followed the "Do not play God" principle, which limited their decisional autonomy, not allowing them to decide on behalf of others.

Hydrophobic modification of jute fiber used for composite reinforcement via laccase-mediated grafting

NASA Astrophysics Data System (ADS)

Dong, Aixue; Yu, Yuanyuan; Yuan, Jiugang; Wang, Qiang; Fan, Xuerong

2014-05-01

Jute fiber is a lignocellulosic material which could be utilized for reinforcement of composites. To improve the compatibility of hydrophilic jute fiber with hydrophobic resin, surface hydrophobization of the fiber is often needed. In this study, the feasibility of laccase-mediated grafting dodecyl gallate (DG) on the jute fiber was investigated. First, the grafting products were characterized by FT-IR, XPS, SEM and AFM. And then the grafting percentage (Gp) and the DG content of the modified jute were determined in terms of weighting and saponification, respectively. The parameters of the enzymatic grafting process were optimized to the target application. Lastly, the hydrophobicity of the jute fabrics was estimated by means of contact angle and wetting time. The mechanical properties and the fracture section of the jute fabric/polypropylene (PP) composites were studied. The results revealed covalently coupling of DG to the jute substrates mediated by laccase. The enzymatic process reached the maximum grafting rate of 4.16% when the jute fabric was incubated in the 80/20 (v/v, %) pH 3 0.2 M acetate buffer/ethanol medium with 1.0 U/mL laccase and 5 mM DG at 50 °C for 4 h. The jute fabric modified with laccase and DG showed increased contact angle of 111.49° and wetting time of at least 30 min, indicating that the surface hydrophobicity of the jute fabric was increased after the enzymatic graft modification with hydrophobic DG. The breaking strength of the modified jute fiber/PP composite was also increased and the fracture section became neat and regular due to the laccase-assisted grafting with DG.

Epileptiform activity induced by lowering extracellular [Mg2+] in combined hippocampal-entorhinal cortex slices: modulation by receptors for norepinephrine and N-methyl-D-aspartate.

PubMed

Stanton, P K; Jones, R S; Mody, I; Heinemann, U

1987-01-01

Reduction of extracellular Mg2+ concentration induced spontaneous and evoked epileptiform activity in the entorhinal cortex (EC) and dentate gyrus (DG) of combined hippocampus (HC)-EC slices. Extracellular field potentials, as well as changes in extracellular Ca2+ and K+ concentrations, were measured in EC and DG with ion-selective/reference electrodes during both repetitive and single stimuli. In the EC, lowering extracellular [Mg2+] induces both spontaneous and single stimulus evoked ictal events consisting of extracellular negative potential shifts (up to 5 mV, 30 sec), decreases in [Ca2+]0 and increases in [K+]0. In the DG, spontaneous events were much shorter, but similar changes in [Ca2+]0, [K+]0 and field potentials (FPs) could be evoked by brief high-frequency stimulation. In both areas, the N-methyl-D-aspartate (NMDA) receptor antagonist 2-aminophosphonovalerate (2-APV) completely blocked spontaneous as well as stimulus evoked epileptiform events. The neurotransmitter norepinephrine (NE), which has previously been shown to modulate long-term potentiation in the DG, was found to exhibit differential modulation of epileptiform activity in the EC and DG. In the EC, NE, acting via alpha 1-receptors, completely blocked low Mg2+-induced epileptiform activity. In contrast, in the DG, NE exhibited a beta-receptor mediated prolongation of the low Mg2+-induced ictal events, and enhanced the stimulus-induced ionic and field potential changes. From these results, we conclude that lowering extracellular [Mg2+], acting in large part through the removal of the Mg2+ voltage-dependent blockade of NMDA receptors, leads to induction of epileptiform activity in both the EC and DG.(ABSTRACT TRUNCATED AT 250 WORDS)

Synergistic Anticancer Action of Lysosomal Membrane Permeabilization and Glycolysis Inhibition.

PubMed

Kosic, Milica; Arsikin-Csordas, Katarina; Paunovic, Verica; Firestone, Raymond A; Ristic, Biljana; Mircic, Aleksandar; Petricevic, Sasa; Bosnjak, Mihajlo; Zogovic, Nevena; Mandic, Milos; Bumbasirevic, Vladimir; Trajkovic, Vladimir; Harhaji-Trajkovic, Ljubica

2016-10-28

We investigated the in vitro and in vivo anticancer effect of combining lysosomal membrane permeabilization (LMP)-inducing agent N-dodecylimidazole (NDI) with glycolytic inhibitor 2-deoxy-d-glucose (2DG). NDI-triggered LMP and 2DG-mediated glycolysis block synergized in inducing rapid ATP depletion, mitochondrial damage, and reactive oxygen species production, eventually leading to necrotic death of U251 glioma cells but not primary astrocytes. NDI/2DG-induced death of glioma cells was partly prevented by lysosomal cathepsin inhibitor E64 and antioxidant α-tocopherol, suggesting the involvement of LMP and oxidative stress in the observed cytotoxicity. LMP-inducing agent chloroquine also displayed a synergistic anticancer effect with 2DG, whereas glucose deprivation or glycolytic inhibitors iodoacetate and sodium fluoride synergistically cooperated with NDI, thus further indicating that the anticancer effect of NDI/2DG combination was indeed due to LMP and glycolysis block. The two agents synergistically induced ATP depletion, mitochondrial depolarization, oxidative stress, and necrotic death also in B16 mouse melanoma cells. Moreover, the combined oral administration of NDI and 2DG reduced in vivo melanoma growth in C57BL/6 mice by inducing necrotic death of tumor cells, without causing liver, spleen, or kidney toxicity. Based on these results, we propose that NDI-triggered LMP causes initial mitochondrial damage that is further increased by 2DG due to the lack of glycolytic ATP required to maintain mitochondrial health. This leads to a positive feedback cycle of mitochondrial dysfunction, ATP loss, and reactive oxygen species production, culminating in necrotic cell death. Therefore, the combination of LMP-inducing agents and glycolysis inhibitors seems worthy of further exploration as an anticancer strategy. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Role of plasma membrane surface charges in dictating the feasibility of membrane-nanoparticle interactions

NASA Astrophysics Data System (ADS)

Sinha, Shayandev; Jing, Haoyuan; Sachar, Harnoor Singh; Das, Siddhartha

2017-12-01

Receptor-ligand (R-L) binding mediated interactions between the plasma membrane (PM) and a nanoparticle (NP) require the ligand-functionalized NPs to come to a distance of separation (DOS) of at least dRL (length of the R-L complex) from the receptor-bearing membranes. In this letter, we establish that the membrane surface charges and the surrounding ionic environment dictate whether or not the attainment of such a critical DOS is possible. The negatively charged membrane invariably induces a negative electrostatic potential at the NP surface, repelling the NP from the membrane. This is countered by the attractive influences of the thermal fluctuations and van der Waals (vdw) interactions that drive the NP close to the membrane. For a NP approaching the membrane from a distance, the ratio of the repulsive (electrostatic) and attractive (thermal and vdW) effects balances at a critical NP-membrane DOS of dg,c. For a given set of parameters, there can be two possible values of dg,c, namely, dg,c,1 and dg,c,2 with dg,c,1 ≫ dg,c,2. We establish that any R-L mediated NP-membrane interaction is possible only if dRL > dg,c,1. Therefore, our study proposes a design criterion for engineering ligands for a NP that will ensure the appropriate length of the R-L complex in order to ensure the successful membrane-NP interaction in the presence of a given electrostatic environment. Finally, we discuss the manner in which our theory can help designing ligand-grafted NPs for targeted drug delivery, design biomimetics NPs, and also explain various experimental results.

[Application of pylorus-vagus-preserving gastrectomy in early gastric cancer in middle third of stomach].

PubMed

Hu, Junfeng; Shao, Qinshu; Sun, Yuanshui; Xu, Xiaodong; Xu, Ji

2015-04-14

To evaluate the long-term outcomes of pylorus-vagus-preserving partial gastrectomy for early gastric cancer in middle third of stomach. Between January 2004 and June 2009, 46 patients with early gastric cancer in middle third of stomach underwent pylorus-vagus-preserving partial gastrectomy (PPG) while another 85 patients had conventional distal gastrectomy (DG). Clinicopathologic data and follow-up results of two groups were analyzed retrospectively, including the results of subjective nutritional assessments, laboratory blood biochemical data, endoscopic findings of remnant stomach and total 5-year survival rates. Postprandial dumping syndrome occurred in 7 patients (8.2%) in DG group while no syndrome occurred in PPG group. The incidence of gallbladder stones at 18 months after operation in DG group was higher than that in PPG group. Significant difference existed between two groups (P<0.05). Even though no significant difference existed in laboratory blood biochemical data and endoscopic findings, PPG group recovered better and regurgitation was frequently found in DG group. Food residue in gastric remnant was frequently observed in PPG (31.1%) than in DG (10.8%, P<0.05) by endoscopic findings. At 2 years post-operation, the postoperative 5-year recurrence rate was 6.5% (2/46) in PPG group versus 8.2% (7/85) in DG group. However no significant difference existed between 2 groups (P=0.724). No significant difference existed between PPG group (91.3%) and DG group (90.6%) in overall 5-year survival rate. For early gastric cancer in middle third of stomach, pylorus-vagus-preserving partial gastrectomy is effective in maintaining postoperative function. And it has the same postoperative survival rate as conventional distal gastrectomy.

The Directorate-General for Health and Consumers 1999-2014: An assessment of its functional capacities.

PubMed

Clemens, Timo; Sørensen, Kristine; Rosenkötter, Nicole; Michelsen, Kai; Brand, Helmut

2017-06-01

Capacity assessment has become a popular measure in the health sector to assess the ability of various stakeholders to pursue agreed activities. The European Commission (EC) is increasingly dealing with a variety of health issues to coordinate and complement national health policies. This study analyses the functional capacity of the Directorate-General for Health and Consumers (DG SANCO) between 1999 and 2004. It applies the UNDP Capacity Assessment Framework and uses a literature review, a document review of EU policy documents and expert interviews to assess the capacity of DG SANCO to fulfill its mandate for public health and health systems. Our results suggest that DG SANCO has established capacities to engage with stakeholders; to assess various health issues, to define issue-specific health policies and to collect information for evaluative purposes. In contrast, capacities tend to be less established for defining a clear strategy for the overall sector, for setting priorities and for budgeting, managing and implementing policies. We conclude that improvements to the effectiveness of DG SANTE's (the successor of DG SANCO) policies can be made within the existing mandate. A priority setting exercise may be conducted to limit the number of pursued actions to those with the greatest European added value within DG SANTE's responsibilities. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Results of 244 consecutive patients with hemorrhoids treated with Doppler-guided hemorrhoidal artery ligation.

PubMed

Pol, Robert A; van der Zwet, Wil C; Hoornenborg, Daniel; Makkinga, Babbeth; Kaijser, Miriam; Eeftinck Schattenkerk, M; Eddes, Eric-Hans

2010-01-01

This study was designed to determine the effect of treating hemorrhoids with the Doppler-guided hemorrhoidal artery ligation (DG-HAL) procedure. From June 2005 to March 2008, 244 consecutive hemorrhoidal patients underwent hemorroidal artery ligation performed with the DG-HAL system from AMI. All patients were evaluated postoperatively with a proctologic examination and interview. Further follow-up was performed by telephone with a standardized questionnaire. When indicated, patients revisited the clinic for further examination and treatment. 244 patients were treated with DG-HAL. The mean follow-up time was 18.4 months (range 1.4-37.2). Sixty-seven percent of the patients had an improvement of symptoms after one treatment. Fifty-three patients (22%) underwent a second procedure because of persisting symptoms. Thirteen patients (25%) underwent a second DG-HAL and 40 (75%) underwent rubber band ligation. In total, 69% of the patients had a good response using the DG-HAL technique. Multivariate logistic regression analysis revealed prolapse to be an independent risk factor for persistent symptoms (OR = 2.38, 95% CI 1.10-5.15). Patients with grades 3 and 4 hemorrhoids had a higher risk of developing recurrent disease (OR = 4.94, 95% CI 0.67-36.42). DG-HAL seems to be an effective procedure for treating low-grade hemorrhoids. A resection procedure should be the treatment for patients with recurrent disease. Copyright 2010 S. Karger AG, Basel.

Early Dexamethasone Treatment Induces Placental Apoptosis in Sheep

PubMed Central

Meng, Wenbin; Shang, Hongkai; Li, Shaofu; Sloboda, Deborah M.; Ehrlich, Loreen; Lange, Karolin; Xu, Huaisheng; Henrich, Wolfgang; Dudenhausen, Joachim W.; Plagemann, Andreas; Newnham, John P.; Challis, John R. G.

2015-01-01

Glucocorticoid treatment given in late pregnancy in sheep resulted in altered placental development and function. An imbalance of placental survival and apoptotic factors resulting in an increased rate of apoptosis may be involved. We have now investigated the effects of dexamethasone (DEX) in early pregnancy on binucleate cells (BNCs), placental apoptosis, and fetal sex as a determinant of these responses. Pregnant ewes carrying singleton fetuses (n = 105) were randomized to control (n = 56, 2 mL saline/ewe) or DEX treatment (n = 49, intramuscular injections of 0.14 mg/kg ewe weight per 12 hours over 48 hours) at 40 to 41 days of gestation (dG). Placentomes were collected at 50, 100, 125, and 140 dG. At 100 dG, DEX in females reduced BNC numbers, placental antiapoptotic (proliferating cell nuclear antigen), and increased proapoptotic factors (Bax, p53), associated with a temporarily decrease in fetal growth. At 125 dG, BNC numbers and apoptotic markers were restored to normal. In males, ovine placental lactogen-protein levels after DEX were increased at 50 dG, but at 100 and 140 dG significantly decreased compared to controls. In contrast to females, these changes were independent of altered BNC numbers or apoptotic markers. Early DEX was associated with sex-specific, transient alterations in BNC numbers, which may contribute to changes in placental and fetal development. Furthermore, in females, altered placental apoptosis markers may be involved. PMID:25063551

A CLASS OF RECONSTRUCTED DISCONTINUOUS GALERKIN METHODS IN COMPUTATIONAL FLUID DYNAMICS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong Luo; Yidong Xia; Robert Nourgaliev

2011-05-01

A class of reconstructed discontinuous Galerkin (DG) methods is presented to solve compressible flow problems on arbitrary grids. The idea is to combine the efficiency of the reconstruction methods in finite volume methods and the accuracy of the DG methods to obtain a better numerical algorithm in computational fluid dynamics. The beauty of the resulting reconstructed discontinuous Galerkin (RDG) methods is that they provide a unified formulation for both finite volume and DG methods, and contain both classical finite volume and standard DG methods as two special cases of the RDG methods, and thus allow for a direct efficiency comparison.more » Both Green-Gauss and least-squares reconstruction methods and a least-squares recovery method are presented to obtain a quadratic polynomial representation of the underlying linear discontinuous Galerkin solution on each cell via a so-called in-cell reconstruction process. The devised in-cell reconstruction is aimed to augment the accuracy of the discontinuous Galerkin method by increasing the order of the underlying polynomial solution. These three reconstructed discontinuous Galerkin methods are used to compute a variety of compressible flow problems on arbitrary meshes to assess their accuracy. The numerical experiments demonstrate that all three reconstructed discontinuous Galerkin methods can significantly improve the accuracy of the underlying second-order DG method, although the least-squares reconstructed DG method provides the best performance in terms of both accuracy, efficiency, and robustness.« less

Lentiviral silencing of GSK-3β in adult dentate gyrus impairs contextual fear memory and synaptic plasticity

PubMed Central

Chew, Benjamin; Ryu, Jae Ryun; Ng, Teclise; Ma, Dongliang; Dasgupta, Ananya; Neo, Sin Hui; Zhao, Jing; Zhong, Zhong; Bichler, Zoë; Sajikumar, Sreedharan; Goh, Eyleen L. K.

2015-01-01

Attempts have been made to use glycogen synthase kinase-3 beta (GSK3β) inhibitors for prophylactic treatment of neurocognitive conditions. However the use of lithium, a non-specific inhibitor of GSK3β results in mild cognitive impairment in humans. The effects of global GSK3β inhibition or knockout on learning and memory in healthy adult mice are also inconclusive. Our study aims to better understand the role of GSK3β in learning and memory through a more regionally, targeted approach, specifically performing lentiviral-mediated knockdown of GSK3β within the dentate gyrus (DG). DG-GSK3β-silenced mice showed impaired contextual fear memory retrieval. However, cue fear memory, spatial memory, locomotor activity and anxiety levels were similar to control. These GSK3β-silenced mice also showed increased induction and maintenance of DG long-term potentiation (DG-LTP) compared to control animals. Thus, this region-specific, targeted knockdown of GSK3β in the DG provides better understanding on the role of GSK3β in learning and memory. PMID:26157370

Inhalation developmental toxicology studies: Teratology study of acetone in mice and rats: Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mast, T.J.; Evanoff, J.J.; Rommereim, R.L.

1988-11-01

Acetone, an aliphatic ketone, is a ubiquitous industrial solvent and chemical intermediate; consequently, the opportunity for human exposure is high. The potential for acetone to cause developmental toxicity was assessed in Sprague-Dawley rats exposed to 0, 440, 2200, or 11000 ppm, and in Swiss (CD-1) mice exposed to 0, 440, 2200, and 6600 ppm acetone vapors, 6 h/day, 7 days/week. Each of the four treatment groups consisted of 10 virgin females (for comparison), and approx.32 positively mated rats or mice. Positively mated mice were exposed on days 6-17 of gestation (dg), and rats on 6-19 dg. The day of plugmore » or sperm detection was designated as 0 dg. Body weights were obtained throughout the study period, and uterine and fetal body weights were obtained at sacrifice (rats, 20 dg; mice, 18 dg). Implants were enumerated and their status recorded. Live fetuses were sexed and examined for gross, visceral, skeletal, and soft-tissue craniofacial defects. 46 refs., 6 figs., 27 tabs.« less

Fermi/LAT detection of a transient gamma-ray flare in the vicinity of the binary star DG CVn

DOE PAGES

Loh, Alan; Corbel, Stéphane; Dubus, Guillaume

2017-02-16

Solar flares are regularly detected by the Large Area Telescope (LAT) on board the Fermi satellite, however no γ-ray emission from other stellar eruptions has ever been captured. The Swift detection in 2014 April of a powerful outburst originating from DG CVn, with associated optical and radio emissions, enticed us to search for possible 0.1–100 GeV emission from this flaring nearby binary star using the Fermi/LAT. No γ-ray emission is detected from DG CVn in 2014, but we report a significant γ-ray excess in 2012 November, at a position consistent with that of the binary. There are no reports ofmore » contemporary flaring at other wavelengths from DG CVn or any other source within the error circle of the γ-ray source. As a result, we argue that the γ-ray flare is more likely to have been associated with a background blazar than with DG CVn and identify a candidate for follow-up study.« less

Reference Range of Platelet Delta Granules in the Pediatric Age Group: An Ultrastructural Study of Platelet Whole Mount Preparations from Healthy Volunteers.

PubMed

Sorokin, Victoria; Alkhoury, Razan; Al-Rawabdeh, Sura; Houston, Ronald H; Thornton, David; Kerlin, Bryce; O'Brien, Sarah; Baker, Peter; Boesel, Carl; Uddin, Minhaj; Yin, Han; Kahwash, Samir

This study sought to determine delta granule normal ranges for children and to validate methodology for the appropriate diagnosis of delta granule deficiency (storage pool disease) by using the whole-mount technique in electron microscopy. Specimens obtained from 40 healthy volunteers (2 months of age through 21 years old, 21 females and 19 males) were tested. Results showed dense granules/platelet (DG/Plt) ranged from 1.78 to 5.25. The 5th percentile was 1.96 DG/Plt with an overall mean ± SEM 3.07 ± 0.12 DG/Plt. In comparison, a previously published lower cutoff value, 3.68 DG/Plt, was significantly higher than the mean from our volunteers (P < 0.0001). We found no variability in dense granules/platelet based on race or sex and no significant variation by age subgroup. Pending wider studies, the value of 2 DG/Plt is a more appropriate lower limit of normal. In the absence of wider studies (in healthy volunteers and patients), laboratories should consider establishing their own reference ranges.

Elucidation of Different Binding Modes of Purine Nucleosides to Human Deoxycytidine Kinase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sabini, Elisabetta; Hazra, Saugata; Konrad, Manfred

2008-07-30

Purine nucleoside analogues of medicinal importance, such as cladribine, require phosphorylation by deoxycytidine kinase (dCK) for pharmacological activity. Structural studies of ternary complexes of human dCK show that the enzyme conformation adjusts to the different hydrogen-bonding properties between dA and dG and to the presence of substituent at the 2-position present in dG and cladribine. Specifically, the carbonyl group in dG elicits a previously unseen conformational adjustment of the active site residues Arg104 and Asp133. In addition, dG and cladribine adopt the anti conformation, in contrast to the syn conformation observed with dA. Kinetic analysis reveals that cladribine is phosphorylatedmore » at the highest efficiency with UTP as donor. We attribute this to the ability of cladribine to combine advantageous properties from dA (favorable hydrogen-bonding pattern) and dG (propensity to bind to the enzyme in its anti conformation), suggesting that dA analogues with a substituent at the 2-position are likely to be better activated by human dCK.« less

5-HT1A Receptors on Mature Dentate Gyrus Granule Cells are Critical for the Antidepressant Response

PubMed Central

Samuels, Benjamin Adam; Anacker, Christoph; Hu, Alice; Levinstein, Marjorie R.; Pickenhagen, Anouchka; Tsetsenis, Theodore; Madroñal, Noelia; Donaldson, Zoe R.; Drew, Liam John; Dranovsky, Alex; Gross, Cornelius T.; Tanaka, Kenji F.; Hen, René

2015-01-01

Selective serotonin reuptake inhibitors (SSRIs) are widely used antidepressants, but the mechanisms by which they influence behavior are only partially resolved. Adult hippocampal neurogenesis is necessary for some of the responses to SSRIs, but it is unknown whether the mature dentate gyrus granule cells (mature DG GCs) also contribute. We deleted Serotonin 1A receptor (5HT1AR; a receptor required for the SSRI response) specifically from DG GCs and found that the effects of the SSRI fluoxetine on behavior and the Hypothalamic-Pituitary-Adrenal (HPA) axis were abolished. By contrast, mice lacking 5HT1ARs only in young adult born granule cells (abGCs) showed normal fluoxetine responses. Importantly, 5HT1AR deficient mice engineered to express functional 5HT1ARs only in DG GCs responded to fluoxetine, indicating that 5HT1ARs in DG GCs are sufficient to mediate an antidepressant response. Taken together, these data indicate that both mature DG GCs and young abGCs must be engaged for an antidepressant response. PMID:26389840

Specific CA3 neurons decode neural information of dentate granule cells evoked by paired-pulse stimulation in co-cultured networks.

PubMed

Poli, Daniele; DeMarse, Thomas B; Wheeler, Bruce C; Brewer, Gregory J

2017-07-01

CA3 and dentate gyrus (DG) neurons are cultured in two-chamber devices on multi-electrode arrays (MEAs) and connected via micro-tunnels. In order to evoke time-locked activity, paired-pulse stimulation is applied to 22 different sites and repeated 25 times in each well in 5 MEA co-cultures and results compared to CA3-CA3 and DG-DG networks homologous controls. In these hippocampal sub-regions, we focus on the mechanisms underpinning a network's ability to decode the identity of site specific stimulation from analysis of evoked network responses using a support vector machine classifier. Our results indicate that a pool of CA3 neurons is able to reliably decode the identity of DG stimulation site information.

Absolute quantification of regional cerebral glucose utilization in mice by 18F-FDG small animal PET scanning and 2-14C-DG autoradiography.

PubMed

Toyama, Hiroshi; Ichise, Masanori; Liow, Jeih-San; Modell, Kendra J; Vines, Douglass C; Esaki, Takanori; Cook, Michelle; Seidel, Jurgen; Sokoloff, Louis; Green, Michael V; Innis, Robert B

2004-08-01

The purpose of this study was to evaluate the feasibility of absolute quantification of regional cerebral glucose utilization (rCMR(glc)) in mice by use of (18)F-FDG and a small animal PET scanner. rCMR(glc) determined with (18)F-FDG PET was compared with values determined simultaneously by the autoradiographic 2-(14)C-DG method. In addition, we compared the rCMR(glc) values under isoflurane, ketamine and xylazine anesthesia, and awake states. Immediately after injection of (18)F-FDG and 2-(14)C-DG into mice, timed arterial samples were drawn over 45 min to determine the time courses of (18)F-FDG and 2-(14)C-DG. Animals were euthanized at 45 min and their brain was imaged with the PET scanner. The brains were then processed for 2-(14)C-DG autoradiography. Regions of interest were manually placed over cortical regions on corresponding coronal (18)F-FDG PET and 2-(14)C-DG autoradiographic images. rCMR(glc) values were calculated for both tracers by the autoradiographic 2-(14)C-DG method with modifications for the different rate and lumped constants for the 2 tracers. Average rCMR(glc) values in cerebral cortex with (18)F-FDG PET under normoglycemic conditions (isoflurane and awake) were generally lower (by 8.3%) but strongly correlated with those of 2-(14)C-DG (r(2) = 0.95). On the other hand, under hyperglycemic conditions (ketamine/xylazine) average cortical rCMR(glc) values with (18)F-FDG PET were higher (by 17.3%) than those with 2-(14)C-DG. Values for rCMR(glc) and uptake (percentage injected dose per gram [%ID/g]) with (18)F-FDG PET were significantly lower under both isoflurane and ketamine/xylazine anesthesia than in the awake mice. However, the reductions of rCMR(glc) were markedly greater under isoflurane (by 57%) than under ketamine and xylazine (by 19%), whereas more marked reductions of %ID/g were observed with ketamine/xylazine (by 54%) than with isoflurane (by 37%). These reverse differences between isoflurane and ketamine/xylazine may be due to competitive effect of (18)F-FDG and glucose uptake to the brain under hyperglycemia. We were able to obtain accurate absolute quantification of rCMR(glc) with mouse (18)F-FDG PET imaging as confirmed by concurrent use of the autoradiographic 2-(14)C-DG method. Underestimation of rCMR(glc) by (18)F-FDG in normoglycemic conditions may be due to partial-volume effects. Computation of rCMR(glc) from (18)F-FDG data in hyperglycemic animals may require, however, alternative rate and lumped constants for (18)F-FDG.

(99m)Tc-labeled gastrins of varying peptide chain length: Distinct impact of NEP/ACE-inhibition on stability and tumor uptake in mice.

PubMed

Kaloudi, Aikaterini; Nock, Berthold A; Lymperis, Emmanouil; Krenning, Eric P; de Jong, Marion; Maina, Theodosia

2016-06-01

In situ inhibition of neutral endopeptidase (NEP) has been recently shown to impressively increase the bioavailability and tumor uptake of biodegradable gastrin radioligands. Furthermore, angiotensin converting enzyme (ACE) has been previously shown to cleave gastrin analogs in vitro. In the present study, we have assessed the effects induced by single or dual NEP/ACE-inhibition on the pharmacokinetic profile of three (99m)Tc-labeled gastrins of varying peptide chain length: [(99m)Tc]SG6 ([(99m)Tc-N4-Gln(1)]gastrin(1-17)), [(99m)Tc]DG2 ([(99m)Tc-N4-Gly(4),DGlu(5)]gastrin(4-17)) and [(99m)Tc]DG4 ([(99m)Tc-N4-DGlu(10)]gastrin(10-17)). Mouse blood samples were collected 5min after injection of each of [(99m)Tc]SG6/DG2/DG4 together with: a) vehicle, b) the NEP-inhibitor phosphoramidon (PA), c) the ACE-inhibitor lisinopril (Lis), or d) PA plus Lis and were analyzed by RP-HPLC for radiometabolite detection. Biodistribution was studied in SCID mice bearing A431-CCK2R(+/-) xenografts at 4h postinjection (pi). [(99m)Tc]SG6 or [(99m)Tc]DG4 was coinjected with either vehicle or the above described NEP/ACE-inhibitor regimens; for [(99m)Tc]DG2 control and PA animal groups were only included. Treatment of mice with PA induced significant stabilization of (99m)Tc-radiotracers in peripheral blood, while treatment with Lis or Lis+PA affected the stability of des(Glu)5 [(99m)Tc]DG4 only. In line with these findings, PA coinjection led to notable amplification of tumor uptake of radiopeptides compared to controls (P<0.01). Only [(99m)Tc]DG4 profited by single Lis (2.06±0.39%ID/g vs 0.99±0.13%ID/g in controls) or combined Lis+PA coinjection (8.91±1.61%ID/g vs 4.89±1.33%ID/g in PA-group). Furthermore, kidney uptake remained favourably low and unaffected by PA and/or Lis coinjection only in the case of [(99m)Tc]DG4 (<1.9%ID/g) resulting in the most optimal tumor-to-kidney ratios. In situ NEP/ACE-inhibition diversely affected the in vivo profile of (99m)Tc-radioligands based on different-length gastrins. Truncated [(99m)Tc]DG4 exhibited overall the most attractive profile during combined NEP/ACE-inhibition in mouse models, providing new opportunities for CCK2R-expressing tumor imaging in man with SPECT. Copyright © 2016 Elsevier Inc. All rights reserved.

Mobile Augmented Reality: Applications and Human Factors Evaluations

DTIC Science & Technology

2006-06-01

Reconstruction, Kluwer Academic Publishers. [8] M.A. Livingston, L.J. Rosenblum, S.J. Julier, D.G. Brown, Y. Baillot, J.E. Swan II, J.L. Gabbard , and D...Education Conference. [9] M.A. Livingston, J.E. Swan II, J.L. Gabbard , T. Höllerer, D. Hix, S.J. Julier, Y. Baillot, and D.G. Brown (2003...J.E. Swan II, M.A. Livingston, H.S. Smallman, D.G. Brown, Y. Baillot, J.L. Gabbard , and D. Hix (2006). “A Perceptual Matching Technique for Depth

An Optimization and Assessment on DG adoption in JapanesePrototype Buildings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Nan; Marnay, Chris; Firestone, Ryan

2005-11-30

This research investigates a method of choosing economicallyoptimal DER, expanding on prior studies at the Berkeley Lab using the DERdesign optimization program, the Distributed Energy Resources CustomerAdoption Model (DER-CAM). DER-CAM finds the optimal combination ofinstalled equipment from available DER technologies, given prevailingutility tariffs, site electrical and thermal loads, and a menu ofavailable equipment. It provides a global optimization, albeit idealized,that shows how the site energy load scan be served at minimum cost byselection and operation of on-site generation, heat recovery, andcooling. Five prototype Japanese commercial buildings are examined andDER-CAM applied to select thee conomically optimal DER system for each.The fivemore » building types are office, hospital, hotel, retail, and sportsfacility. Based on the optimization results, energy and emissionreductions are evaluated. Furthermore, a Japan-U.S. comparison study ofpolicy, technology, and utility tariffs relevant to DER installation ispresented. Significant decreases in fuel consumption, carbon emissions,and energy costs were seen in the DER-CAM results. Savings were mostnoticeable in the sports facility, followed by the hospital, hotel, andoffice building.« less

Frequency Based Real-time Pricing for Residential Prosumers

NASA Astrophysics Data System (ADS)

Hambridge, Sarah Mabel

This work is the first to explore frequency based pricing for secondary frequency control as a price-reactive control mechanism for residential prosumers. A frequency based real-time electricity rate is designed as an autonomous market control mechanism for residential prosumers to provide frequency support as an ancillary service. In addition, prosumers are empowered to participate in dynamic energy transactions, therefore integrating Distributed Energy Resources (DERs), and increasing distributed energy storage onto the distributed grid. As the grid transitions towards DERs, a new market based control system will take the place of the legacy distributed system and possibly the legacy bulk power system. DERs provide many benefits such as energy independence, clean generation, efficiency, and reliability to prosumers during blackouts. However, the variable nature of renewable energy and current lack of installed energy storage on the grid will create imbalances in supply and demand as uptake increases, affecting the grid frequency and system operation. Through a frequency-based electricity rate, prosumers will be encouraged to purchase energy storage systems (ESS) to offset their neighbor's distributed generation (DG) such as solar. Chapter 1 explains the deregulation of the power system and move towards Distributed System Operators (DSOs), as prosumers become owners of microgrids and energy cells connected to the distributed system. Dynamic pricing has been proposed as a benefit to prosumers, giving them the ability to make decisions in the energy market, while also providing a way to influence and control their behavior. Frequency based real-time pricing is a type of dynamic pricing which falls between price-reactive control and transactive control. Prosumer-to-prosumer transactions may take the place of prosumer-to-utility transactions, building The Energy Internet. Frequency based pricing could be a mechanism for determining prosumer prices and supporting stability in a free, competitive, market. Frequency based pricing is applied to secondary frequency control in this work, providing support at one to five minute time intervals. In Chapter 2, a frequency based pricing curve is designed as a preliminary study and the response of the prosumer is optimized for economic dispatch. In Chapter 3, a day-ahead schedule and real-time adjustment energy management framework is presented for the prosumer, creating a market structure similar to the existing energy market supervised by Independent System Operators (ISOs). Enabling technology, such as the solid state transformer (SST) is described for prosumer energy transactions, controlling power flow from the prosumer's energy cell to the grid or neighboring prosumer as an energy router. Experimental results are shown to demonstrate this capability. Additionally, the SST is capable of measuring the grid frequency. Lastly, a frequency based real-time hybrid electricity rate is presented in Chapter 4 and Chapter 5. Chapter 4 specializes in a single direction rate while Chapter 5 presents a bi-directional rate. A Time-of-use (TOU) rate is combined with the real-time frequency based price to lower energy bills for a residential prosumer with ESS, in agreement with the proposed day-ahead and real-time energy management framework. The cost to the ESS is also considered in this section. Linear programming and strategic rule based methods are utilized to find the lowest energy bill. As a result, prosumers can use ESS to balance the grid, reducing their bill as much per kWh as PV or DG under a TOU net-metering price scheme, while providing distributed frequency support to the grid authority. The variability of the frequency based rate is similar to variability in the stock market, which gives a sense of how prosumers will interact with variable prices in a system supported by The Energy Internet.

Effects of electrical stimulation of the rat vestibular labyrinth on c-Fos expression in the hippocampus.

PubMed

Hitier, Martin; Sato, Go; Zhang, Yan-Feng; Besnard, Stephane; Smith, Paul F

2018-06-11

Several studies have demonstrated that electrical activation of the peripheral vestibular system can evoke field potential, multi-unit neuronal activity and acetylcholine release in the hippocampus (HPC). However, no study to date has employed the immediate early gene protein, c-Fos, to investigate the distribution of activation of cells in the HPC following electrical stimulation of the vestibular system. We found that vestibular stimulation increased the number of animals expressing c-Fos in the dorsal HPC compared to sham control rats (P ≤ 0.02), but not in the ventral HPC. c-Fos was also expressed in an increased number of animals in the dorsal dentate gyrus (DG) compared to sham control rats (P ≤ 0.0001), and to a lesser extent in the ventral DG (P ≤ 0.006). The results of this study show that activation of the vestibular system results in a differential increase in the expression of c-Fos across different regions of the HPC. Copyright © 2018 Elsevier B.V. All rights reserved.

2-Deoxy-D-glucose, not mercaptoacetate, induces a reversible reduction of body temperature in male desert hamsters (Phodopus roborovskii).

PubMed

Chi, Qing-Sheng; Li, Xiu-Juan; Wang, De-Hua

2018-01-01

The initiation of torpor is supposed to be related to the availability of metabolic fuels. Studies on metabolic fuel inhibition of glucose by using 2-deoxy-D-glucose (2DG) or fatty acid by mercaptoacetate (MA) in heterothermic mammals produced mixed outcomes. To examine the roles of availability of glucose and fatty acid in the initiation of torpor in desert hamsters (Phodopus roborovskii), we intraperitoneally administrated 2DG and MA to summer-acclimated male hamsters while body temperature (T b ), metabolic rate (MR) and respiratory quotient (RQ) were simultaneously recorded to monitor their thermoregulatory response. 2DG induced a reversible reduction of T b in desert hamsters both at ambient temperature (T a ) of 23°C and 5°C. At T a of 23°C, T b , MR and RQ decreased in a dose-dependent manner with a large T b -T a differential (> 6.5°C) and a lowest T b of 28.0°C which were comparable to those in fasted hamsters. At T a of 5°C, 2DG-treated hamsters also decreased T b to the same level as at T a 23°C, but MR was significantly higher than that at T a of 23°C at each dose, suggesting doses of 2DG directly affected the hypothalamic T b set-point. Different from fasted hamsters which maintain normothermic at T a of 5°C, 2DG-treated hamsters showed a substantial reduction of T b at T a 5°C, indic a ting an overwhelming effect on the thermoregulatory system regardless of T a . Furthermore, the rapid decrease of T b and outstretched body posture in 2DG-treated hamsters suggest that the effects of 2DG were not simply mimicking the torpor pathways but that other mechanisms are involved. Interestingly, MA failed to induce a torpor-like state in male desert hamsters. Our results suggest that availability of glucose rather than fatty acid plays an important role for initiation of torpor in desert hamsters. Copyright © 2017 Elsevier Ltd. All rights reserved.

Neuron-restrictive silencer factor is not required for the antiepileptic effect of the ketogenic diet.

PubMed

Hu, Xiao-Ling; Cheng, Xuewen; Fei, Jian; Xiong, Zhi-Qi

2011-09-01

The ketogenic diet (KD) has been used as an effective antiepileptic treatment for nearly a century. Inhibition of glycolysis and increased levels of ketone bodies are both known to contribute to the antiepileptic effects of the KD. Neuron-restrictive silencer factor (NRSF), also known as RE-1 silencing transcription factor (REST), is implicated in the antiepileptic effects of the glycolytic inhibitor 2-deoxy-d-glucose (2DG). Glycolytic inhibition is a common feature of the KD and 2DG treatment, leading to the hypothesis that NRSF might also be involved in the antiepileptic effect of the KD. To test this hypothesis, the present study was designed to investigate the role of NRSF in the antiepileptic effect of 2DG, the KD, and acetone in vivo. Kindling was used as a model to test the antiepileptic effects of 2DG, the KD, and acetone on control and NRSF conditional knockout mice (NRSF-cKO; from the intercross of CamKIIα-iCre and NRSF exon 2 floxed mice). After recovery from electrode implantation, adult mice were stimulated twice a day at afterdischarge threshold (ADT) current intensity. In the 2DG- (500 mg/kg) and acetone- (10 mmol/kg) treated groups, drugs were injected intraperitoneally 20 min before each stimulus. In the 2DG group, mice were pretreated with intraperitoneal injections for 3 days in addition to the injections administered before the regular kindling stimulation. In the KD group, mice were fed the KD instead of a control diet until the end of stimulations. Compared with control mice, the antiepileptic effect of 2DG was abolished in NRSF-cKO mice, indicating that NRSF is required for the antiepileptic effect of 2DG. In the KD-fed group, kindling development was retarded in both control and NRSF-cKO mice. In the acetone-treated group, inhibition of kindling-induced epileptogenesis was observed in both control and NRSF-cKO mice, similar to the action of the KD. These findings imply that NRSF repression complex is not essential for the antiepileptic effect of the ketogenic diet. Wiley Periodicals, Inc. © 2011 International League Against Epilepsy.

Pre-steady-state kinetic investigation of bypass of a bulky guanine lesion by human Y-family DNA polymerases.

PubMed

Tokarsky, E John; Gadkari, Varun V; Zahurancik, Walter J; Malik, Chanchal K; Basu, Ashis K; Suo, Zucai

2016-10-01

3-Nitrobenzanthrone (3-NBA), a byproduct of diesel exhaust, is highly present in the environment and poses a significant health risk. Exposure to 3-NBA results in formation of N-(2'-deoxyguanosin-8-yl)-3-aminobenzanthrone (dG C8- N -ABA ), a bulky DNA lesion that is of particular importance due to its mutagenic and carcinogenic potential. If not repaired or bypassed during genomic replication, dG C8- N -ABA can stall replication forks, leading to senescence and cell death. Here we used pre-steady-state kinetic methods to determine which of the four human Y-family DNA polymerases (hPolη, hPolκ, hPolι, or hRev1) are able to catalyze translesion synthesis of dG C8- N -ABA in vitro. Our studies demonstrated that hPolη and hPolκ most efficiently bypassed a site-specifically placed dG C8- N- ABA lesion, making them good candidates for catalyzing translesion synthesis (TLS) of this bulky lesion in vivo. Consistently, our publication (Biochemistry 53, 5323-31) in 2014 has shown that small interfering RNA-mediated knockdown of hPolη and hPolκ in HEK293T cells significantly reduces the efficiency of TLS of dG C8- N -ABA . In contrast, hPolι and hRev1 were severely stalled by dG C8- N -ABA and their potential role in vivo was discussed. Subsequently, we determined the kinetic parameters for correct and incorrect nucleotide incorporation catalyzed by hPolη at various positions upstream, opposite, and downstream from dG C8- N- ABA . Notably, nucleotide incorporation efficiency and fidelity both decreased significantly during dG C8- N -ABA bypass and the subsequent extension step, leading to polymerase pausing and error-prone DNA synthesis by hPolη. Furthermore, hPolη displayed nucleotide concentration-dependent biphasic kinetics at the two polymerase pause sites, suggesting that multiple enzyme•DNA complexes likely exist during nucleotide incorporation. Copyright © 2016 Elsevier B.V. All rights reserved.

Ablation of the presynaptic organizer Bassoon in excitatory neurons retards dentate gyrus maturation and enhances learning performance.

PubMed

Annamneedi, Anil; Caliskan, Gürsel; Müller, Sabrina; Montag, Dirk; Budinger, Eike; Angenstein, Frank; Fejtova, Anna; Tischmeyer, Wolfgang; Gundelfinger, Eckart D; Stork, Oliver

2018-06-18

Bassoon is a large scaffolding protein of the presynaptic active zone involved in the development of presynaptic terminals and in the regulation of neurotransmitter release at both excitatory and inhibitory brain synapses. Mice with constitutive ablation of the Bassoon (Bsn) gene display impaired presynaptic function, show sensory deficits and develop severe seizures. To specifically study the role of Bassoon at excitatory forebrain synapses and its relevance for control of behavior, we generated conditional knockout (Bsn cKO) mice by gene ablation through an Emx1 promoter-driven Cre recombinase. In these animals, we confirm selective loss of Bassoon from glutamatergic neurons of the forebrain. Behavioral assessment revealed that, in comparison to wild-type littermates, Bsn cKO mice display selectively enhanced contextual fear memory and increased novelty preference in a spatial discrimination/pattern separation task. These changes are accompanied by an augmentation of baseline synaptic transmission at medial perforant path to dentate gyrus (DG) synapses, as indicated by increased ratios of field excitatory postsynaptic potential slope to fiber volley amplitude. At the structural level, an increased complexity of apical dendrites of DG granule cells can be detected in Bsn cKO mice. In addition, alterations in the expression of cellular maturation markers and a lack of age-dependent decrease in excitability between juvenile and adult Bsn cKO mice are observed. Our data suggest that expression of Bassoon in excitatory forebrain neurons is required for the normal maturation of the DG and important for spatial and contextual memory.

Functional optical probing of the hippocampal trisynaptic circuit in vitro: network dynamics, filter properties, and polysynaptic induction of CA1 LTP.

PubMed

Stepan, Jens; Dine, Julien; Eder, Matthias

2015-01-01

Decades of brain research have identified various parallel loops linking the hippocampus with neocortical areas, enabling the acquisition of spatial and episodic memories. Especially the hippocampal trisynaptic circuit [entorhinal cortex layer II → dentate gyrus (DG) → cornu ammonis (CA)-3 → CA1] was studied in great detail because of its seemingly simple connectivity and characteristic structures that are experimentally well accessible. While numerous researchers focused on functional aspects, obtained from a limited number of cells in distinct hippocampal subregions, little is known about the neuronal network dynamics which drive information across multiple synapses for subsequent long-term storage. Fast voltage-sensitive dye imaging in vitro allows real-time recording of activity patterns in large/meso-scale neuronal networks with high spatial resolution. In this way, we recently found that entorhinal theta-frequency input to the DG most effectively passes filter mechanisms of the trisynaptic circuit network, generating activity waves which propagate across the entire DG-CA axis. These "trisynaptic circuit waves" involve high-frequency firing of CA3 pyramidal neurons, leading to a rapid induction of classical NMDA receptor-dependent long-term potentiation (LTP) at CA3-CA1 synapses (CA1 LTP). CA1 LTP has been substantially evidenced to be essential for some forms of explicit learning in mammals. Here, we review data with particular reference to whole network-level approaches, illustrating how activity propagation can take place within the trisynaptic circuit to drive formation of CA1 LTP.

Combustion Characteristics of Hydrocarbon Droplets Induced by Photoignition of Aluminum Nanoparticles (Conference Paper with Briefing Charts)

DTIC Science & Technology

2017-04-23

192. 4. Chehroudi, B., Davis, D.W., and Talley, D.G., "The Effects of Pressure and Acoustic Field on a Cryogenic Coaxial Jet", 42nd AIAA Aerospace...the Presence of Acoustic Excitation", Combustion and Flame, 2014; 6, 161, pp. 1604-1619. 15. Glassman, I., and Yetter, R.A., Combustion: Fourth...pressure vessel. - Investigate combustion dynamics of nanofuel sprays under acoustic forcing at supercritical conditions (>600 psi). 3 DISTRIBUTION A

Manufacturing Cost/Design Guide (MC/DG) for Conceptual Design. Supplement

DTIC Science & Technology

1989-08-01

theprdctipinofthiina~ e~e~~ to - -ý - - . .-.--- leen shl . maka In - n rerduto Ift data in whole or in part. WRNING This document contains technical data whose...Distribution authorized to US G~ov’t agencies 2b OECLASSIPICATION/COOWNRAOINO SCMIIUOJL only; cri ti cal techriol oqy; May 1989. N /A Ote eussfrti...under a series of contracts. These contracts, design curves, etc., are listed inne•,u~ C Prfrmnc u •,, Worl - u~e l- n S l rgan n a number of tedms. The

Regulating the interpersonal self: strategic self-regulation for coping with rejection sensitivity.

PubMed

Ayduk, O; Mendoza-Denton, R; Mischel, W; Downey, G; Peake, P K; Rodriguez, M

2000-11-01

People high in rejection sensitivity (RS) anxiously expect rejection and are at risk for interpersonal and personal distress. Two studies examined the role of self-regulation through strategic attention deployment in moderating the link between RS and maladaptive outcomes. Self-regulation was assessed by the delay of gratification (DG) paradigm in childhood. In Study 1, preschoolers from the Stanford University community who participated in the DG paradigm were assessed 20 years later. Study 2 assessed low-income, minority middle school children on comparable measures. DG ability buffered high-RS people from interpersonal difficulties (aggression, peer rejection) and diminished well-being (e.g., low self-worth, higher drug use). The protective effect of DG ability on high-RS children's self-worth is explained by reduced interpersonal problems. Attentional mechanisms underlying the interaction between RS and strategic self-regulation are discussed.

Synthesis of dibenzodioxazocines and their effects on cholinesterases and muscarinic cholinergic receptors.

PubMed

Gaál, J; Batke, J; Borsodi, A; Rózsa, L; Somogyi, G

1989-01-01

A new family of tricyclic compounds, the dibenzodioxazocines were synthesized. These compounds were the following: 2-chloro-12-(2-piperidino-ethyl)-dibenzo d,g 1,3,6 dioxazocine hydrochloride: EGYT-2347, 2-chloro-12-(3-dimethylamino-2-methyl-propyl)-dibenzo [d,g] [1,3,6]-dibenzodioxazocine hydrochloride: EGYT-2509, 2-chloro-12-(3-dimethylamino-propyl)-dibenzo [d,g] [1,3,6] dioxazocine-maleate: EGYT-2474 and 2-chloro-12-2-(4-methyl-piperazino)-ethyl-dibenzo [d,g] [1,3,6]-dioxazocine-dihydrochloride: EGYT-2541. These compounds are inhibitors of both butyryl- and acetylcholinesterase to and they exhibited relatively good anticholinergic properties in receptor binding experiments. The most selective inhibitor of butyrylcholinesterase is the compound EGYT-2347 (Ki = 1.5 x 10(-7) M) which strongly binds to rat brain muscarinic cholinergic receptor (KD = 4.1 x 10(-8) M).

The 8th and 9th tandem spectrin-like repeats of utrophin cooperatively form a functional unit to interact with polarity-regulating kinase PAR-1b.

PubMed

Yamashita, Kazunari; Suzuki, Atsushi; Satoh, Yoshinori; Ide, Mariko; Amano, Yoshiko; Masuda-Hirata, Maki; Hayashi, Yukiko K; Hamada, Keisuke; Ogata, Kazuhiro; Ohno, Shigeo

2010-01-01

Utrophin is a widely expressed paralogue of dystrophin, the protein responsible for Duchenne muscular dystrophy. Utrophin is a large spectrin-like protein whose C-terminal domain mediates anchorage to a laminin receptor, dystroglycan (DG). The rod domain, composed of 22 spectrin-like repeats, connects the N-terminal actin-binding domain and the C-terminal DG binding domain, and thus mediates molecular linkage between intracellular F-actin and extracellular basement membrane. Previously, we demonstrated that a cell polarity-regulating kinase, PAR-1b, interacts with the utrophin-DG complex, and positively regulates the interaction between utrophin and DG. In this study, we demonstrate that the 8th and 9th spectrin-like repeats (R8 and R9) of utrophin cooperatively form a PAR-1b-interacting domain, and that Ser1258 within R9 is specifically phosphorylated by PAR-1b. Substitution of Ser1258 to alanine reduces the interaction between utrophin and DG, suggesting that the Ser1258 phosphorylation contributes to the stabilization of the utrophin-DG complex. Interestingly, PAR-1b also binds and phosphorylates R8-9 of dystrophin, and colocalizes with dystrophin at the skeletal muscle membrane. These results reveal a novel function of the rod domain of utrophin beyond that of a passive structural linker connecting the N- and C-terminal domain. Copyright 2009 Elsevier Inc. All rights reserved.

Effects of 2-deoxy-D-glucose administration on cytokine production in BDF1 mice

NASA Technical Reports Server (NTRS)

Dreau, D.; Morton, D. S.; Foster, M.; Fowler, N.; Sonnenfeld, G.

2000-01-01

Physical exercise and diet changes have been shown to affect immune parameters, and similar effects are also induced by the administration of a nonmetabolizable glucose analog, 2-deoxy-D-glucose (2-DG). The present study was designed to characterize the effects of glucoprivation induced by 2-DG administration on concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and IL-6 in the blood and interferon-gamma (IFN-gamma), IL-2, and IL-4 in vitro production by partially purified T splenocytes in BDF1 mice. Mice (n = 8 per group) were injected intraperitoneally one or three times with 0, 500, 750, or 1000 mg/kg of 2-DG, and blood and spleens were collected 2 h after the last injection. Partially purified T splenocytes were cultured 24 h in the presence of concanavalin A (ConA). A significant increase in the corticosterone levels with the amount of 2-DG injected was observed after one or three injections (p<0.05). The amount of 2-DG injected was associated with an increase in TNF-alpha, IL-1beta, and IL-6 concentrations in the blood of mice after one or three injections of 2-DG (p<0.05). A significant decrease in in vitro proliferation of partially purified splenocytes in the presence of ConA was associated with a decrease in IFN-gamma production in the culture supernatants and an increase in IL-1 receptor expression on the cell surface (p<0.05).

Hybrid Fourier pseudospectral/discontinuous Galerkin time-domain method for wave propagation

NASA Astrophysics Data System (ADS)

Pagán Muñoz, Raúl; Hornikx, Maarten

2017-11-01

The Fourier Pseudospectral time-domain (Fourier PSTD) method was shown to be an efficient way of modelling acoustic propagation problems as described by the linearized Euler equations (LEE), but is limited to real-valued frequency independent boundary conditions and predominantly staircase-like boundary shapes. This paper presents a hybrid approach to solve the LEE, coupling Fourier PSTD with a nodal Discontinuous Galerkin (DG) method. DG exhibits almost no restrictions with respect to geometrical complexity or boundary conditions. The aim of this novel method is to allow the computation of complex geometries and to be a step towards the implementation of frequency dependent boundary conditions by using the benefits of DG at the boundaries, while keeping the efficient Fourier PSTD in the bulk of the domain. The hybridization approach is based on conformal meshes to avoid spatial interpolation of the DG solutions when transferring values from DG to Fourier PSTD, while the data transfer from Fourier PSTD to DG is done utilizing spectral interpolation of the Fourier PSTD solutions. The accuracy of the hybrid approach is presented for one- and two-dimensional acoustic problems and the main sources of error are investigated. It is concluded that the hybrid methodology does not introduce significant errors compared to the Fourier PSTD stand-alone solver. An example of a cylinder scattering problem is presented and accurate results have been obtained when using the proposed approach. Finally, no instabilities were found during long-time calculation using the current hybrid methodology on a two-dimensional domain.

Methamphetamine decreases dentate gyrus stem cell self-renewal and shifts the differentiation towards neuronal fate.

PubMed

Baptista, Sofia; Lasgi, Charlène; Benstaali, Caroline; Milhazes, Nuno; Borges, Fernanda; Fontes-Ribeiro, Carlos; Agasse, Fabienne; Silva, Ana Paula

2014-09-01

Methamphetamine (METH) is a highly addictive psychostimulant drug of abuse that negatively interferes with neurogenesis. In fact, we have previously shown that METH triggers stem/progenitor cell death and decreases neuronal differentiation in the dentate gyrus (DG). Still, little is known regarding its effect on DG stem cell properties. Herein, we investigate the impact of METH on mice DG stem/progenitor cell self-renewal functions. METH (10nM) decreased DG stem cell self-renewal, while 1nM delayed cell cycle in the G0/G1-to-S phase transition and increased the number of quiescent cells (G0 phase), which correlated with a decrease in cyclin E, pEGFR and pERK1/2 protein levels. Importantly, both drug concentrations (1 or 10nM) did not induce cell death. In accordance with the impairment of self-renewal capacity, METH (10nM) decreased Sox2(+)/Sox2(+) while increased Sox2(-)/Sox2(-) pairs of daughter cells. This effect relied on N-methyl-d-aspartate (NMDA) signaling, which was prevented by the NMDA receptor antagonist, MK-801 (10μM). Moreover, METH (10nM) increased doublecortin (DCX) protein levels consistent with neuronal differentiation. In conclusion, METH alters DG stem cell properties by delaying cell cycle and decreasing self-renewal capacities, mechanisms that may contribute to DG neurogenesis impairment followed by cognitive deficits verified in METH consumers. Copyright © 2014. Published by Elsevier B.V.

Disordered gambling as defined by the Diagnostic and Statistical Manual of Mental Disorders and the South Oaks Gambling Screen: evidence for a common etiologic structure.

PubMed

Slutske, Wendy S; Zhu, Gu; Meier, Madeline H; Martin, Nicholas G

2011-08-01

In a previous article, we demonstrated in a large twin study that disordered gambling (DG), as defined by the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV), ran in families, that about half of the variation in liability for DG was due to familial factors, and that all of this was explained by shared genetic rather than shared environmental influences (Slutske, Zhu, Meier, & Martin, 2010). The purpose of the present study is to extend this work to include an alternative conceptualization of DG that is provided by the South Oaks Gambling Screen (SOGS) item set in order to (a) compare the magnitude of the familial resemblance obtained when using the two definitions of DG (based on the DSM-IV and the SOGS), (b) examine the extent to which the 2 definitions tap the same underlying sources of genetic and environmental variation, and (c) examine whether the same results will be obtained among men and women. The results of bivariate twin model-fitting analyses suggested that DG, as defined by the DSM-IV and the SOGS, substantially overlapped at the etiologic level among both men and women, which supports the construct validity of both the DSM and the SOGS conceptualizations of DG. This study highlights the utility of twin studies for appraising the validity of the diagnostic nomenclature. © 2011 American Psychological Association

HiCoDG: a hierarchical data-gathering scheme using cooperative multiple mobile elements.

PubMed

Van Le, Duc; Oh, Hoon; Yoon, Seokhoon

2014-12-17

In this paper, we study mobile element (ME)-based data-gathering schemes in wireless sensor networks. Due to the physical speed limits of mobile elements, the existing data-gathering schemes that use mobile elements can suffer from high data-gathering latency. In order to address this problem, this paper proposes a new hierarchical and cooperative data-gathering (HiCoDG) scheme that enables multiple mobile elements to cooperate with each other to collect and relay data. In HiCoDG, two types of mobile elements are used: the mobile collector (MC) and the mobile relay (MR). MCs collect data from sensors and forward them to the MR, which will deliver them to the sink. In this work, we also formulated an integer linear programming (ILP) optimization problem to find the optimal trajectories for MCs and the MR, such that the traveling distance of MEs is minimized. Two variants of HiCoDG, intermediate station (IS)-based and cooperative movement scheduling (CMS)-based, are proposed to facilitate cooperative data forwarding from MCs to the MR. An analytical model for estimating the average data-gathering latency in HiCoDG was also designed. Simulations were performed to compare the performance of the IS and CMS variants, as well as a multiple traveling salesman problem (mTSP)-based approach. The simulation results show that HiCoDG outperforms mTSP in terms of latency. The results also show that CMS can achieve the lowest latency with low energy consumption.

HiCoDG: A Hierarchical Data-Gathering Scheme Using Cooperative Multiple Mobile Elements †

PubMed Central

Van Le, Duc; Oh, Hoon; Yoon, Seokhoon

2014-01-01

In this paper, we study mobile element (ME)-based data-gathering schemes in wireless sensor networks. Due to the physical speed limits of mobile elements, the existing data-gathering schemes that use mobile elements can suffer from high data-gathering latency. In order to address this problem, this paper proposes a new hierarchical and cooperative data-gathering (HiCoDG) scheme that enables multiple mobile elements to cooperate with each other to collect and relay data. In HiCoDG, two types of mobile elements are used: the mobile collector (MC) and the mobile relay (MR). MCs collect data from sensors and forward them to the MR, which will deliver them to the sink. In this work, we also formulated an integer linear programming (ILP) optimization problem to find the optimal trajectories for MCs and the MR, such that the traveling distance of MEs is minimized. Two variants of HiCoDG, intermediate station (IS)-based and cooperative movement scheduling (CMS)-based, are proposed to facilitate cooperative data forwarding from MCs to the MR. An analytical model for estimating the average data-gathering latency in HiCoDG was also designed. Simulations were performed to compare the performance of the IS and CMS variants, as well as a multiple traveling salesman problem (mTSP)-based approach. The simulation results show that HiCoDG outperforms mTSP in terms of latency. The results also show that CMS can achieve the lowest latency with low energy consumption. PMID:25526356

Analysis of high-k spacer on symmetric underlap DG-MOSFET with Gate Stack architecture

NASA Astrophysics Data System (ADS)

Das, Rahul; Chakraborty, Shramana; Dasgupta, Arpan; Dutta, Arka; Kundu, Atanu; Sarkar, Chandan K.

2016-09-01

This paper shows the systematic study of underlap double gate (U-DG) NMOSFETs with Gate Stack (GS) under the influence of high-k spacers. In highly scaled devices, underlap is used at the Source and Drain side so as to reduce the short channel effects (SCE's), however, it significantly reduces the on current due to the increased channel resistance. To overcome these drawbacks, the use of high-k spacers is projected as one of the remedies. In this paper, the analog performance of the devices is studied on the basis of parameters like transconductance (gm), transconductance generation factor (gm/Id) and intrinsic gain (gmro). The RF performance is analyzed on the merits of intrinsic capacitance (Cgd, Cgs), resistance (Rgd, Rgs), transport delay (τm), inductance (Lsd), cutoff frequency (fT), and the maximum frequency of oscillation (fmax). The circuit performance of the devices are studied by implementing the device as the driver MOSFET in a Single Stage Common Source Amplifier. The Gain Bandwidth Product (GBW) has been analyzed from the frequency response of the circuit.

High glucose-induced resistance to 5-fluorouracil in pancreatic cancer cells alleviated by 2-deoxy-D-glucose.

PubMed

Cheng, Yao; Diao, Dongmei; Zhang, Hao; Guo, Qi; Wu, Xuandi; Song, Yongchun; Dang, Chengxue

2014-03-01

Abnormal glucose metabolism from hyperglycemia or diabetes aggravates the progression of pancreatic cancer. It is unknown whether high glucose has an impact on the antitumor effect of 5-fluorouracil (5-Fu) and whether targeting aberrant glucose metabolism using 2-deoxy-D-glucose (2-DG) may reverse this effect in high-glucose microenvironments. The cell viability of AsPC-1 and Panc-1 was analyzed by MTT assay following 5-Fu treatment at different glucose concentrations. Altered sensitivity to 5-Fu by 2-DG was also analyzed. LY294002 was used to inhibit PI3K-Akt signaling to determine the mechanism involved. In response to glucose, 5-Fu-induced cell growth inhibition was attenuated in a dose-dependent manner, accompanied with activated p-Akt, while 2-DG enhanced 5-Fu-induced cell growth inhibition. Moreover, blocking the PI3K/Akt pathway by LY294002 effectively eliminated 2-DG-induced apoptosis. In conclusion, high glucose weakens the antitumor effect of 5-Fu via PI3K / Akt signaling. Using 2-DG in combination with 5-Fu significantly increased their therapeutic effectiveness in high-glucose microenvironments.

Facile construction of 3D graphene/MoS2 composites as advanced electrode materials for supercapacitors

NASA Astrophysics Data System (ADS)

Sun, Tianhua; Li, Zhangpeng; Liu, Xiaohong; Ma, Limin; Wang, Jinqing; Yang, Shengrong

2016-11-01

Flower-like molybdenum disulfide (MoS2) microstructures are synthesized based on three-dimensional graphene (3DG) skeleton via a simple and facile one-step hydrothermal method, aiming at constructing series of novel composite electrode materials of 3DG/MoS2 with high electrochemical performances for supercapacitors. The electrochemical properties of the samples are evaluated by cyclic voltammetry and galvanostatic charge/discharge tests. Specifically, the optimal 3DG/MoS2 composite exhibits remarkable performances with a high specific capacitance of 410 F g-1 at a current density of 1 A g-1 and an excellent cycling stability with ca. 80.3% capacitance retention after 10,000 continuous charge-discharge cycles at a high current density of 2 A g-1, making it adaptive for high-performance supercapacitors. The enhanced electrochemical performances can be ascribed to the combination of 3DG and flower-like MoS2, which provides excellent charge transfer network and electrolyte diffusion channels while effectively prevents the collapse, aggregation and morphology change of active materials during charge-discharge process. The results demonstrate that 3DG/MoS2 composite is one of the attractive electrode materials for supercapacitors.

Multi-Dimensional Quantum Tunneling and Transport Using the Density-Gradient Model

NASA Technical Reports Server (NTRS)

Biegel, Bryan A.; Yu, Zhi-Ping; Ancona, Mario; Rafferty, Conor; Saini, Subhash (Technical Monitor)

1999-01-01

We show that quantum effects are likely to significantly degrade the performance of MOSFETs (metal oxide semiconductor field effect transistor) as these devices are scaled below 100 nm channel length and 2 nm oxide thickness over the next decade. A general and computationally efficient electronic device model including quantum effects would allow us to monitor and mitigate these effects. Full quantum models are too expensive in multi-dimensions. Using a general but efficient PDE solver called PROPHET, we implemented the density-gradient (DG) quantum correction to the industry-dominant classical drift-diffusion (DD) model. The DG model efficiently includes quantum carrier profile smoothing and tunneling in multi-dimensions and for any electronic device structure. We show that the DG model reduces DD model error from as much as 50% down to a few percent in comparison to thin oxide MOS capacitance measurements. We also show the first DG simulations of gate oxide tunneling and transverse current flow in ultra-scaled MOSFETs. The advantages of rapid model implementation using the PDE solver approach will be demonstrated, as well as the applicability of the DG model to any electronic device structure.

2-Deoxyglucose conjugated platinum (II) complexes for targeted therapy: design, synthesis, and antitumor activity.

PubMed

Mi, Qian; Ma, Yuru; Gao, Xiangqian; Liu, Ran; Liu, Pengxing; Mi, Yi; Fu, Xuegang; Gao, Qingzhi

2016-11-01

Malignant neoplasms exhibit an elevated rate of glycolysis over normal cells. To target the Warburg effect, we designed a new series of 2-deoxyglucose (2-DG) conjugated platinum (II) complexes for glucose transporter 1 (GLUT1)-mediated anticancer drug delivery. The potential GLUT1 transportability of the complexes was investigated through a comparative molecular docking analysis utilizing the latest GLUT1 protein crystal structure. The key binding site for 2-DG as GLUT1's substrate was identified with molecular dynamics simulation, and the docking study demonstrated that the 2-DG conjugated platinum (II) complexes can be recognized by the same binding site as potential GLUT1 substrate. The conjugates were synthesized and evaluated for in vitro cytotoxicity study with seven human cancer cell lines. The results of this study revealed that 2-DG conjugated platinum (II) complexes are GLUT1 transportable substrates and exhibit improved cytotoxicities in cancer cell lines that over express GLUT1 when compared to the clinical drug, Oxaliplatin. The correlation between GLUT1 expression and antitumor effects are also confirmed. The study provides fundamental information supporting the potential of the 2-DG conjugated platinum (II) complexes as lead compounds for further pharmaceutical R&D.

ADER discontinuous Galerkin schemes for general-relativistic ideal magnetohydrodynamics

NASA Astrophysics Data System (ADS)

Fambri, F.; Dumbser, M.; Köppel, S.; Rezzolla, L.; Zanotti, O.

2018-07-01

We present a new class of high-order accurate numerical algorithms for solving the equations of general-relativistic ideal magnetohydrodynamics in curved space-times. In this paper, we assume the background space-time to be given and static, i.e. we make use of the Cowling approximation. The governing partial differential equations are solved via a new family of fully discrete and arbitrary high-order accurate path-conservative discontinuous Galerkin (DG) finite-element methods combined with adaptive mesh refinement and time accurate local time-stepping. In order to deal with shock waves and other discontinuities, the high-order DG schemes are supplemented with a novel a posteriori subcell finite-volume limiter, which makes the new algorithms as robust as classical second-order total-variation diminishing finite-volume methods at shocks and discontinuities, but also as accurate as unlimited high-order DG schemes in smooth regions of the flow. We show the advantages of this new approach by means of various classical two- and three-dimensional benchmark problems on fixed space-times. Finally, we present a performance and accuracy comparisons between Runge-Kutta DG schemes and ADER high-order finite-volume schemes, showing the higher efficiency of DG schemes.

Angiogenin activates phospholipase C and elicits a rapid incorporation of fatty acid into cholesterol esters in vascular smooth muscle cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, F.; Riordan, J.F.

1990-01-09

Angiogenin activates the phosphoinositide-specific phospholipase C (PLC) in cultured rat aortic smooth muscle cells to yield a transient (30 s) peak of 1,2-diacylglycerol (DG) and inositol trisphosphate. Within 1 min, the DG level falls below that of the control and remains so for at least 20 min. A transient increase in monoacylglycerol indicates that depletion of DG may be the consequence of hydrolysis by DG lipase. In addition to these changes in second messengers, a rapid increase in incorporating of radiolabeled tracer into cellular cholesterol esters is observed. Stimulated cholesterol ester labeling is inhibited by preincubation with either the DGmore » lipase inhibitor RHC 80267 or the acyl coenzyme A:cholesterol acyltransferase inhibitor Sandoz 58035. Cells prelabeled with ({sup 3}H)arachidonate show a sustained increase in labeling of cholesterol esters following exposure to angiogenin. In contrast, cells prelabeled with ({sup 3}H)oleate show only a transient elevation that returns to the basal level by 5 min. This suggests initial cholesterol esterification by oleate followed by arachidonate that is released by stimulation of the PLC/DG lipase pathway.« less

ADER discontinuous Galerkin schemes for general-relativistic ideal magnetohydrodynamics

NASA Astrophysics Data System (ADS)

Fambri, F.; Dumbser, M.; Köppel, S.; Rezzolla, L.; Zanotti, O.

2018-03-01

We present a new class of high-order accurate numerical algorithms for solving the equations of general-relativistic ideal magnetohydrodynamics in curved spacetimes. In this paper we assume the background spacetime to be given and static, i.e. we make use of the Cowling approximation. The governing partial differential equations are solved via a new family of fully-discrete and arbitrary high-order accurate path-conservative discontinuous Galerkin (DG) finite-element methods combined with adaptive mesh refinement and time accurate local timestepping. In order to deal with shock waves and other discontinuities, the high-order DG schemes are supplemented with a novel a-posteriori subcell finite-volume limiter, which makes the new algorithms as robust as classical second-order total-variation diminishing finite-volume methods at shocks and discontinuities, but also as accurate as unlimited high-order DG schemes in smooth regions of the flow. We show the advantages of this new approach by means of various classical two- and three-dimensional benchmark problems on fixed spacetimes. Finally, we present a performance and accuracy comparisons between Runge-Kutta DG schemes and ADER high-order finite-volume schemes, showing the higher efficiency of DG schemes.

Electrochemical monitoring of chlorhexidine digluconate effect on polyelectrolyte immobilized bacteria and kinetic cell adhesion.

PubMed

Borghol, N; Mora, L; Sakly, N; Lejeune, P; Jouenne, T; Jaffrézic-Renault, N; Othmane, A

2011-01-10

The electrochemical impedance spectroscopy (EIS) technique has been used as a sensitive method to explore the effect of antibacterial molecules on immobilized bacteria and biofilm formation. In this work, we describe the electrochemical spectroscopy as a powerful method to monitor the effect of chlorhexidine digluconate (CHX-Dg) on polyelectrolyte immobilized Escherichia coli K12 MG1655 and the kinetics of cell adhesion on gold electrodes. The experimental impedance data were modeled with a Zview program to find the best equivalent electrical circuit and analyse its parameter's properties. Polyelectrolyte multilayer formation on the electrode surface and bacteria immobilization greatly increased the electron-transfer resistance (R(et)) and reduced the constant phase element (CPE(dl)). The effect of CHX-Dg was studied in a 0.5 x 10⁻⁴ mmol l⁻¹ to 0.5 mmol l⁻¹ range. The relation between the evolution of R(et) and CHX-Dg concentration was found to be negatively correlated. When CHX-Dg was added, the electrochemical monitoring of the bacterial kinetic adhesion showed that the electrode's capacity (C(P)) variation remained stable, demonstrating that the addition of CHX-Dg in the broth inhibited bacterial adhesion. © 2010 Elsevier B.V. All rights reserved.

Impact of negative capacitance effect on Germanium Double Gate pFET for enhanced immunity to interface trap charges

NASA Astrophysics Data System (ADS)

Bansal, Monika; Kaur, Harsupreet

2018-05-01

In this work, a comprehensive drain current model has been developed for long channel Negative Capacitance Germanium Double Gate p-type Field Effect Transistor (NCGe-DG-pFET) by using 1-D Poisson's equation and Landau-Khalatnikov equation. The model takes into account interface trap charges and by using the derived model various parameters such as surface potential, gain, gate capacitance, subthreshold swing, drain current, transconductance, output conductance and Ion/Ioff ratio have been obtained and it is demonstrated that by incorporating ferroelectric material as gate insulator with Ge-channel, subthreshold swing values less than 60 mV/dec can be achieved along with improved gate controllability and current drivability. Further, to critically analyze the advantages offered by NCGe-DG-pFET, a detailed comparison has been done with Germanium Double Gate p-type Field Effect Transistor (Ge-DG-pFET) and it is shown that NCGe-DG-pFET exhibits high gain, enhanced transport efficiency in channel, very less or negligible degradation in device characteristics due to interface trap charges as compared to Ge-DG-pFET. The analytical results so obtained show good agreement with simulated results obtained from Silvaco ATLAS TCAD tool.

The downregulation of sweet taste receptor signaling in enteroendocrine L-cells mediates 3-deoxyglucosone-induced attenuation of high glucose-stimulated GLP-1 secretion.

PubMed

Wang, Fei; Song, Xiudao; Zhou, Liang; Liang, Guoqiang; Huang, Fei; Jiang, Guorong; Zhang, Lurong

2017-12-26

Sweet taste receptors (STRs) involve in regulating the release of glucose-stimulated glucagon-like peptide-1 (GLP-1). Our in vivo and in vitro studies found that 3-deoxyglucosone (3DG) inhibited glucose-stimulated GLP-1 secretion. This study investigated the role of STRs in 3DG-induced inhibition of high glucose-stimulated GLP-1 secretion. STC-1 cells were incubated with lactisole or 3DG for 1 h under 25 mM glucose conditions. Western blotting was used to study the expression of STRs signaling molecules and ELISA was used to analyse GLP-1 and cyclic adenosine monophosphate (cAMP) levels. Lactisole inhibited GLP-1 secretion. Exposure to 25 mM glucose increased the expressions of STRs subunits when compared with 5.6 mM glucose. 3DG decreased GLP-1 secretion and STRs subunits expressions, with affecting other components of STRs pathway, including the downregulation of transient receptor potential cation channel subfamily M member 5 (TRPM5) expression and the reduction of intracellular cAMP levels. 3DG attenuates high glucose-stimulated GLP-1 secretion by reducing STR subunit expression and downstream signaling components.

Energy Stable Flux Formulas For The Discontinuous Galerkin Discretization Of First Order Nonlinear Conservation Laws

NASA Technical Reports Server (NTRS)

Barth, Timothy; Charrier, Pierre; Mansour, Nagi N. (Technical Monitor)

2001-01-01

We consider the discontinuous Galerkin (DG) finite element discretization of first order systems of conservation laws derivable as moments of the kinetic Boltzmann equation. This includes well known conservation law systems such as the Euler For the class of first order nonlinear conservation laws equipped with an entropy extension, an energy analysis of the DG method for the Cauchy initial value problem is developed. Using this DG energy analysis, several new variants of existing numerical flux functions are derived and shown to be energy stable.

Radio variability and structure of T Tauri stars

NASA Technical Reports Server (NTRS)

Cohen, Martin; Bieging, John H.

1986-01-01

Observations of radio variability in V410 Tau and in HP Tau/G2 and /G3, and striking variations in the radio structure of DG Tau, are reported. The position of the radio peak of DG Tau has shown apparent motion between 1982 and 1985 along the flow axis from this star, while its morphology has varied from point-like to bipolar. These changes and the spectral index of 0.6 at high frequencies are interpreted as indicative of a variable, freely expanding radio jet in DG Tau.

Computer Assisted Exercise Environment for Terrorist Attack Consequence Management

DTIC Science & Technology

2006-09-01

security and crisis management. Fig. 3. Third Generation SSR for Integrated Security Sector MoD MoI MoEM MoFA Special Services Integrated Security...Ministries: MoEM , MoI, MoD, MH, MoEW, MoE, MoAF National Media, NGOs, other agencies District EOC / LEMA MHS/IDS/WIS Field EOC MHS/IDS/WIS MHS IDS...SRA EDA DG Environment ... EU SR Fund MoD MoI MoE&S MoEM ... National USA Great Britain Netherlands Germany ... Bilateral BSEC Stab. Pact ... Regional

Severely impaired hippocampal neurogenesis associates with an early serotonergic deficit in a BAC α-synuclein transgenic rat model of Parkinson's disease

PubMed Central

Kohl, Zacharias; Abdallah, Nada Ben; Vogelgsang, Jonathan; Tischer, Lucas; Deusser, Janina; Amato, Davide; Anderson, Scott; Müller, Christian P.; Riess, Olaf; Masliah, Eliezer; Nuber, Silke; Winkler, Jürgen

2016-01-01

Parkinson's disease (PD) is a multisystem disorder, involving several monoaminergic neurotransmitter systems resulting in a broad range of motor and non-motor symptoms. Pathological hallmarks of PD are the loss of dopaminergic neurons and the accumulation of alpha-synuclein, however also being present in the serotonergic raphe nuclei early in the disease course. The dysfunction of the serotonergic system projecting to the hippocampus might contribute to early non-motor symptoms such as anxiety and depression. The adult hippocampal dentate gyrus (DG), a unique niche of the forebrain continuously generating new neurons, may particularly present enhanced susceptibility towards accumulating alpha-synuclein levels. The underlying molecular mechanisms in the context of neuronal maturation and survival of new-born neurons are yet not well understood. To characterize the effects of overexpression of human full-length alpha-synuclein on hippocampal cellular and synaptic plasticity, we used a recently generated BAC alpha-synuclein transgenic rat model showing important features of PD such as widespread and progressive alpha-synuclein aggregation pathology, dopamine loss and age-dependent motor decline. At the age of four months, thus prior to the occurrence of the motor phenotype, we observed a profoundly impaired dendritogenesis of neuroblasts in the hippocampal DG resulting in severely reduced survival of adult new-born neurons. Diminished neurogenesis concurred with a serotonergic deficit in the hippocampus as defined by reduced levels of serotonin (5-HT) 1B receptor, decreased 5-HT neurotransmitter levels, and a loss of serotonergic nerve terminals innervating the DG/CA3 subfield, while the number of serotonergic neurons in the raphe nuclei remained unchanged. Moreover, alpha-synuclein overexpression reduced proteins involved in vesicle release, in particular synapsin-1 and Rab3 interacting molecule (RIM3), in conjunction with an altered ultrastructural architecture of hippocampal synapses. Importantly, alterations of the hippocampal serotonergic system were associated with an anxiety-like behavior consisting of reduced exploratory behavior and feeding in transgenic rats. Taken together, these findings imply that accumulating alpha-synuclein severely affects hippocampal neurogenesis paralleled by impaired 5-HT neurotransmission prior to the onset of aggregation pathology and motor deficits in this transgenic rat model of PD. PMID:26523794

Candidatus Frankia Datiscae Dg1, the Actinobacterial Microsymbiont of Datisca glomerata, Expresses the Canonical nod Genes nodABC in Symbiosis with Its Host Plant

PubMed Central

Persson, Tomas; Battenberg, Kai; Demina, Irina V.; Vigil-Stenman, Theoden; Vanden Heuvel, Brian; Pujic, Petar; Facciotti, Marc T.; Wilbanks, Elizabeth G.; O'Brien, Anna; Fournier, Pascale; Cruz Hernandez, Maria Antonia; Mendoza Herrera, Alberto; Médigue, Claudine; Normand, Philippe; Pawlowski, Katharina; Berry, Alison M.

2015-01-01

Frankia strains are nitrogen-fixing soil actinobacteria that can form root symbioses with actinorhizal plants. Phylogenetically, symbiotic frankiae can be divided into three clusters, and this division also corresponds to host specificity groups. The strains of cluster II which form symbioses with actinorhizal Rosales and Cucurbitales, thus displaying a broad host range, show suprisingly low genetic diversity and to date can not be cultured. The genome of the first representative of this cluster, Candidatus Frankia datiscae Dg1 (Dg1), a microsymbiont of Datisca glomerata, was recently sequenced. A phylogenetic analysis of 50 different housekeeping genes of Dg1 and three published Frankia genomes showed that cluster II is basal among the symbiotic Frankia clusters. Detailed analysis showed that nodules of D. glomerata, independent of the origin of the inoculum, contain several closely related cluster II Frankia operational taxonomic units. Actinorhizal plants and legumes both belong to the nitrogen-fixing plant clade, and bacterial signaling in both groups involves the common symbiotic pathway also used by arbuscular mycorrhizal fungi. However, so far, no molecules resembling rhizobial Nod factors could be isolated from Frankia cultures. Alone among Frankia genomes available to date, the genome of Dg1 contains the canonical nod genes nodA, nodB and nodC known from rhizobia, and these genes are arranged in two operons which are expressed in D. glomerata nodules. Furthermore, Frankia Dg1 nodC was able to partially complement a Rhizobium leguminosarum A34 nodC::Tn5 mutant. Phylogenetic analysis showed that Dg1 Nod proteins are positioned at the root of both α- and β-rhizobial NodABC proteins. NodA-like acyl transferases were found across the phylum Actinobacteria, but among Proteobacteria only in nodulators. Taken together, our evidence indicates an Actinobacterial origin of rhizobial Nod factors. PMID:26020781

Disability Grant: a precarious lifeline for HIV/AIDS patients in South Africa.

PubMed

Govender, Veloshnee; Fried, Jana; Birch, Stephen; Chimbindi, Natsayi; Cleary, Susan

2015-06-09

In South Africa, HIV/AIDS remains a major public health problem. In a context of chronic unemployment and deepening poverty, social assistance through a Disability Grant (DG) is extended to adults with HIV/AIDS who are unable to work because of a mental or physical disability. Using a mixed methods approach, we consider 1) inequalities in access to the DG for patients on ART and 2) implications of DG access for on-going access to healthcare. Data were collected in exit interviews with 1200 ART patients in two rural and two urban health sub-districts in four different South African provinces. Additionally, 17 and 18 in-depth interviews were completed with patients on ART treatment and ART providers, respectively, in three of the four sites included in the quantitative phase. Grant recipients were comparatively worse off than non-recipients in terms of employment (9.1 % vs. 29.9 %) and wealth (58.3 % in the poorest half vs. 45.8 %). After controlling for socioeconomic and demographic factors, site, treatment duration, adherence and concomitant TB treatment, the regression analyses showed that the employed were significantly less likely to receive the DG than the unemployed (p < 0.001). Also, patients who were longer on treatment and receiving concomitant treatment (i.e., ART and tuberculosis care) were more likely to receive the DG (significant at the 5 % level). The qualitative analyses indicated that the DG alleviated the burden of healthcare related costs for ART patients. Both patients and healthcare providers spoke of the complexity of the grants process and eligibility criteria as a barrier to accessing the grant. This impacted adversely on patient-provider relationships. These findings highlight the appropriateness of the DG for people living with HIV/AIDS. However, improved collaboration between the Departments of Social Development and Health is essential for preparing healthcare providers who are at the interface between social security and potential recipients.

Increased Excitatory Synaptic Transmission of Dentate Granule Neurons in Mice Lacking PSD-95-Interacting Adhesion Molecule Neph2/Kirrel3 during the Early Postnatal Period.

PubMed

Roh, Junyeop D; Choi, Su-Yeon; Cho, Yi Sul; Choi, Tae-Yong; Park, Jong-Sil; Cutforth, Tyler; Chung, Woosuk; Park, Hanwool; Lee, Dongsoo; Kim, Myeong-Heui; Lee, Yeunkum; Mo, Seojung; Rhee, Jeong-Seop; Kim, Hyun; Ko, Jaewon; Choi, Se-Young; Bae, Yong Chul; Shen, Kang; Kim, Eunjoon; Han, Kihoon

2017-01-01

Copy number variants and point mutations of NEPH2 (also called KIRREL3 ) gene encoding an immunoglobulin (Ig) superfamily adhesion molecule have been linked to autism spectrum disorders, intellectual disability and neurocognitive delay associated with Jacobsen syndrome, but the physiological roles of Neph2 in the mammalian brain remain largely unknown. Neph2 is highly expressed in the dentate granule (DG) neurons of the hippocampus and is localized in both dendrites and axons. It was recently shown that Neph2 is required for the formation of mossy fiber filopodia, the axon terminal structure of DG neurons forming synapses with GABAergic neurons of CA3. In contrast, however, it is unknown whether Neph2 also has any roles in the postsynaptic compartments of DG neurons. We here report that, through its C-terminal PDZ domain-binding motif, Neph2 directly interacts with postsynaptic density (PSD)-95, an abundant excitatory postsynaptic scaffolding protein. Moreover, Neph2 protein is detected in the brain PSD fraction and interacts with PSD-95 in synaptosomal lysates. Functionally, loss of Neph2 in mice leads to age-specific defects in the synaptic connectivity of DG neurons. Specifically, Neph2 -/- mice show significantly increased spontaneous excitatory synaptic events in DG neurons at postnatal week 2 when the endogenous Neph2 protein expression peaks, but show normal excitatory synaptic transmission at postnatal week 3. The evoked excitatory synaptic transmission and synaptic plasticity of medial perforant pathway (MPP)-DG synapses are also normal in Neph2 -/- mice at postnatal week 3, further confirming the age-specific synaptic defects. Together, our results provide some evidence for the postsynaptic function of Neph2 in DG neurons during the early postnatal period, which might be implicated in neurodevelopmental and cognitive disorders caused by NEPH2 mutations.

In vivo fluorescence imaging of an orthotopic rat bladder tumor model indicates differential uptake of intravesically instilled near-infrared labeled 2-deoxyglucose analog by neoplastic urinary bladder tissues

NASA Astrophysics Data System (ADS)

Piao, Daqing; Davis, Carole A.; Hurst, Robert E.; Slaton, Joel W.

2017-02-01

Bladder cancer is one of the most expensive cancers to manage due to frequent recurrences requiring life-long surveillance and treatment. A near-infrared labeled 2-deoxy-d-glucose probe IRDye800CW-DG targeting glucose metabolism pathway has shown to enhance the sensitivity of diagnosing several types of cancers as tested on tumor models not including bladder tumor. This pilot study has explored differential uptake of intravesically administered IRDye800CW-DG in an orthotopic rat bladder tumor model. Twenty-five female Fischer rats were randomly grouped to four conditions: no-tumor-control (n=3), no-tumor-control intravesically instilled with IRDye800CWDG (n=6), rats bearing GFP-labeled AY-27 rat bladder urothelial cell carcinoma cells and washed with saline (n=5), and rats bearing AY-27 tumors and intravesically instilled with IRDye800CW-DG (n=11). Near-infrared fluorescence was measured from the opened bladder wall of anesthetized rat at an excitation wavelength of 750nm and an emission wavelength of 776nm, by using an in-house fluorescence imaging system. There is no statistically significant difference of the peak fluorescence intensity among the no-tumor-control bladders (n=3), the no-tumorcontrol bladders instilled with IRDye800CW-DG (n=6), and the GFP-labeled AY-27 treated bladders washed by saline (n=5). When compared to that of the no-tumor-control bladders instilled with IRDye800CW-DG (n=6), the fluorescence intensity of GFP-labeled AY-27 treated bladders instilled with IRDye800CW-DG and with histology confirmed neoplastic bladder tissue (n=11) was remarkably more intense (3.34 fold of over the former) and was also statistically significant (p<0.0001). The differential uptake of IRDye800CW-DG by the neoplastic urinary bladder tissues suggests the potential for cystoscopy-adaptation to enhance diagnosis and guiding surgical management of flat urinary bladder cancer.

Bidirectional switch of the valence associated with a hippocampal contextual memory engram.

PubMed

Redondo, Roger L; Kim, Joshua; Arons, Autumn L; Ramirez, Steve; Liu, Xu; Tonegawa, Susumu

2014-09-18

The valence of memories is malleable because of their intrinsic reconstructive property. This property of memory has been used clinically to treat maladaptive behaviours. However, the neuronal mechanisms and brain circuits that enable the switching of the valence of memories remain largely unknown. Here we investigated these mechanisms by applying the recently developed memory engram cell- manipulation technique. We labelled with channelrhodopsin-2 (ChR2) a population of cells in either the dorsal dentate gyrus (DG) of the hippocampus or the basolateral complex of the amygdala (BLA) that were specifically activated during contextual fear or reward conditioning. Both groups of fear-conditioned mice displayed aversive light-dependent responses in an optogenetic place avoidance test, whereas both DG- and BLA-labelled mice that underwent reward conditioning exhibited an appetitive response in an optogenetic place preference test. Next, in an attempt to reverse the valence of memory within a subject, mice whose DG or BLA engram had initially been labelled by contextual fear or reward conditioning were subjected to a second conditioning of the opposite valence while their original DG or BLA engram was reactivated by blue light. Subsequent optogenetic place avoidance and preference tests revealed that although the DG-engram group displayed a response indicating a switch of the memory valence, the BLA-engram group did not. This switch was also evident at the cellular level by a change in functional connectivity between DG engram-bearing cells and BLA engram-bearing cells. Thus, we found that in the DG, the neurons carrying the memory engram of a given neutral context have plasticity such that the valence of a conditioned response evoked by their reactivation can be reversed by re-associating this contextual memory engram with a new unconditioned stimulus of an opposite valence. Our present work provides new insight into the functional neural circuits underlying the malleability of emotional memory.

Bidirectional switch of the valence associated with a hippocampal contextual memory engram

PubMed Central

Redondo, Roger L; Kim, Joshua; Arons, Autumn L; Ramirez, Steve; Liu, Xu; Tonegawa, Susumu

2014-01-01

The valence of memories is malleable because of their intrinsic reconstructive property1. This property of memory has been used clinically to treat maladaptive behaviours2. However, the neuronal mechanisms and brain circuits that enable the switching of the valence of memories remain largely unknown. Here, we investigated these mechanisms by applying the recently developed memory engram cell-labelling and -manipulation technique 3,4. We labelled, with Channelrhodopsin-2 (ChR2), a population of cells in either the dorsal dentate gyrus (DG) of the hippocampus or the basolateral complex of the amygdala (BLA) that were specifically activated during contextual fear or reward conditioning. Both groups of fear-conditioned mice displayed aversive light-dependent responses in an optogenetic place avoidance test, whereas both DG- and BLA-labelled mice that underwent reward conditioning exhibited an appetitive response in an optogenetic place preference test. Next, in an attempt to reverse the valence of memory within a subject, mice whose DG or BLA engram had initially been labelled by contextual fear or reward conditioning were subjected to a second conditioning of the opposite valence while their original DG or BLA engram was reactivated by blue light. Subsequent optogenetic place avoidance and preference tests revealed that while the DG-engram group displayed a response indicating a switch of the memory valence, the BLA-engram group did not. This switch was also evident at the cellular level by a change in functional connectivity between DG engram-bearing cells and BLA engram-bearing cells. Thus, we found that in the DG, the neurons carrying the memory engram of a given neutral context have plasticity such that the valence of a conditioned response evoked by their reactivation can be reversed by re-associating this contextual memory engram with a new US of an opposite valence. Our present work provides new insight into the functional neural circuit underlying the malleability of emotional memory. PMID:25162525

Metabolic rate in different rat brain areas during seizures induced by a specific delta opiate receptor agonist.

PubMed

Haffmans, J; De Kloet, R; Dzoljic, M R

1984-06-04

The glucose utilization during specific delta opiate agonist-induced epileptiform phenomena, determined by the [14C]2-deoxyglucose technique (2-DG), was examined in various rat brain areas at different time intervals. The peak in EEG spiking response and the most intensive 2-DG uptake occurred 5 min after intraventricular (i.v.t.) administration of the delta opiate receptor agonist. The most pronounced 2-DG uptake at this time interval can be observed in the subiculum, including the CA1 hippocampal area, frontal cortex and central amygdala. A general decrease of glucose consumption, compared to control values, is observed after 10 min, in all regions, with exception of the subiculum. Since functional activity and 2-DG uptake are correlated, we suggest that the subiculum and/or CA1 area, are probably the brain regions most involved in the enkephalin-induced epileptic phenomena.

Filter and Grid Resolution in DG-LES

NASA Astrophysics Data System (ADS)

Miao, Ling; Sammak, Shervin; Madnia, Cyrus K.; Givi, Peyman

2017-11-01

The discontinuous Galerkin (DG) methodology has proven very effective for large eddy simulation (LES) of turbulent flows. Two important parameters in DG-LES are the grid resolution (h) and the filter size (Δ). In most previous work, the filter size is usually set to be proportional to the grid spacing. In this work, the DG method is combined with a subgrid scale (SGS) closure which is equivalent to that of the filtered density function (FDF). The resulting hybrid scheme is particularly attractive because a larger portion of the resolved energy is captured as the order of spectral approximation increases. Different cases for LES of a three-dimensional temporally developing mixing layer are appraised and a systematic parametric study is conducted to investigate the effects of grid resolution, the filter width size, and the order of spectral discretization. Comparative assessments are also made via the use of high resolution direct numerical simulation (DNS) data.

Biomolecular Interactions of Tannin Isolated from Oenothera gigas with Liposomes.

PubMed

Sekowski, Szymon; Ionov, Maksim; Dubis, Alina; Mavlyanov, Saidmukhtar; Bryszewska, Maria; Zamaraeva, Maria

2016-04-01

We have examined the interaction between hydrolysable tannin 1-O-galloyl-4,6-hexahydroxydiphenoyl-β-D-glucose (OGβDG) with neutral liposomes as a model of cell membranes composed of three lipids: lecithin, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) at different mass ratios. OGβDG in the concentration range 0.5-15 µg/ml (0.4-12 µM) strongly interacts with liposomal membranes by changing their structure, surface charge and fluidity. Used OGβDG molecules decrease and increase the rigidity of hydrophilic surface and hydrophobic parts of liposomes, respectively. At higher concentrations of tannin (>15 µM), liposomes are aggregated. Fourier Transform Infra-Red (FTIR) analysis showed that mainly -OH groups from OGβDG and also PO(2-) groups from phospholipids are responsible for the interaction. Obtained data indicate the importance of membrane lipid composition in interactions between tannins and cells.

A second order discontinuous Galerkin fast sweeping method for Eikonal equations

NASA Astrophysics Data System (ADS)

Li, Fengyan; Shu, Chi-Wang; Zhang, Yong-Tao; Zhao, Hongkai

2008-09-01

In this paper, we construct a second order fast sweeping method with a discontinuous Galerkin (DG) local solver for computing viscosity solutions of a class of static Hamilton-Jacobi equations, namely the Eikonal equations. Our piecewise linear DG local solver is built on a DG method developed recently [Y. Cheng, C.-W. Shu, A discontinuous Galerkin finite element method for directly solving the Hamilton-Jacobi equations, Journal of Computational Physics 223 (2007) 398-415] for the time-dependent Hamilton-Jacobi equations. The causality property of Eikonal equations is incorporated into the design of this solver. The resulting local nonlinear system in the Gauss-Seidel iterations is a simple quadratic system and can be solved explicitly. The compactness of the DG method and the fast sweeping strategy lead to fast convergence of the new scheme for Eikonal equations. Extensive numerical examples verify efficiency, convergence and second order accuracy of the proposed method.

DG TO FT - AUTOMATIC TRANSLATION OF DIGRAPH TO FAULT TREE MODELS

NASA Technical Reports Server (NTRS)

Iverson, D. L.

1994-01-01

Fault tree and digraph models are frequently used for system failure analysis. Both types of models represent a failure space view of the system using AND and OR nodes in a directed graph structure. Each model has its advantages. While digraphs can be derived in a fairly straightforward manner from system schematics and knowledge about component failure modes and system design, fault tree structure allows for fast processing using efficient techniques developed for tree data structures. The similarities between digraphs and fault trees permits the information encoded in the digraph to be translated into a logically equivalent fault tree. The DG TO FT translation tool will automatically translate digraph models, including those with loops or cycles, into fault tree models that have the same minimum cut set solutions as the input digraph. This tool could be useful, for example, if some parts of a system have been modeled using digraphs and others using fault trees. The digraphs could be translated and incorporated into the fault trees, allowing them to be analyzed using a number of powerful fault tree processing codes, such as cut set and quantitative solution codes. A cut set for a given node is a group of failure events that will cause the failure of the node. A minimum cut set for a node is any cut set that, if any of the failures in the set were to be removed, the occurrence of the other failures in the set will not cause the failure of the event represented by the node. Cut sets calculations can be used to find dependencies, weak links, and vital system components whose failures would cause serious systems failure. The DG TO FT translation system reads in a digraph with each node listed as a separate object in the input file. The user specifies a terminal node for the digraph that will be used as the top node of the resulting fault tree. A fault tree basic event node representing the failure of that digraph node is created and becomes a child of the terminal root node. A subtree is created for each of the inputs to the digraph terminal node and the root of those subtrees are added as children of the top node of the fault tree. Every node in the digraph upstream of the terminal node will be visited and converted. During the conversion process, the algorithm keeps track of the path from the digraph terminal node to the current digraph node. If a node is visited twice, then the program has found a cycle in the digraph. This cycle is broken by finding the minimal cut sets of the twice visited digraph node and forming those cut sets into subtrees. Another implementation of the algorithm resolves loops by building a subtree based on the digraph minimal cut sets calculation. It does not reduce the subtree to minimal cut set form. This second implementation produces larger fault trees, but runs much faster than the version using minimal cut sets since it does not spend time reducing the subtrees to minimal cut sets. The fault trees produced by DG TO FT will contain OR gates, AND gates, Basic Event nodes, and NOP gates. The results of a translation can be output as a text object description of the fault tree similar to the text digraph input format. The translator can also output a LISP language formatted file and an augmented LISP file which can be used by the FTDS (ARC-13019) diagnosis system, available from COSMIC, which performs diagnostic reasoning using the fault tree as a knowledge base. DG TO FT is written in C-language to be machine independent. It has been successfully implemented on a Sun running SunOS, a DECstation running ULTRIX, a Macintosh running System 7, and a DEC VAX running VMS. The RAM requirement varies with the size of the models. DG TO FT is available in UNIX tar format on a .25 inch streaming magnetic tape cartridge (standard distribution) or on a 3.5 inch diskette. It is also available on a 3.5 inch Macintosh format diskette or on a 9-track 1600 BPI magnetic tape in DEC VAX FILES-11 format. Sample input and sample output are provided on the distribution medium. An electronic copy of the documentation in Macintosh Microsoft Word format is provided on the distribution medium. DG TO FT was developed in 1992. Sun, and SunOS are trademarks of Sun Microsystems, Inc. DECstation, ULTRIX, VAX, and VMS are trademarks of Digital Equipment Corporation. UNIX is a registered trademark of AT&T Bell Laboratories. Macintosh is a registered trademark of Apple Computer, Inc. System 7 is a trademark of Apple Computers Inc. Microsoft Word is a trademark of Microsoft Corporation.

Bypass of Aflatoxin B[subscript 1] Adducts by the Sulfolobus solfataricus DNA Polymerase IV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banerjee, Surajit; Brown, Kyle L.; Egli, Martin

Aflatoxin B{sub 1} (AFB{sub 1}) is oxidized to an epoxide in vivo, which forms an N7-dG DNA adduct (AFB{sub 1}-N7-dG). The AFB{sub 1}-N7-dG can rearrange to a formamidopyrimidine (AFB{sub 1}-FAPY) derivative. Both AFB{sub 1}-N7-dG and the {beta}-anomer of the AFB{sub 1}-FAPY adduct yield G {yields} T transversions in Escherichia coli, but the latter is more mutagenic. We show that the Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4) bypasses AFB{sub 1}-N7-dG in an error-free manner but conducts error-prone replication past the AFB{sub 1}-FAPY adduct, including misinsertion of dATP, consistent with the G {yields} T mutations observed in E. coli. Three ternarymore » (Dpo4-DNA-dNTP) structures with AFB{sub 1}-N7-dG adducted template:primers have been solved. These demonstrate insertion of dCTP opposite the AFB{sub 1}-N7-dG adduct, and correct vs incorrect insertion of dATP vs dTTP opposite the 5'-template neighbor dT from a primed AFB{sub 1}-N7-dG:dC pair. The insertion of dTTP reveals hydrogen bonding between the template N3 imino proton and the O{sup 2} oxygen of dTTP, and between the template T O{sup 4} oxygen and the N3 imino proton of dTTP, perhaps explaining why this polymerase does not efficiently catalyze phosphodiester bond formation from this mispair. The AFB{sub 1}-N7-dG maintains the 5'-intercalation of the AFB{sub 1} moiety observed in DNA. The bond between N7-dG and C8 of the AFB{sub 1} moiety remains in plane with the alkylated guanine, creating a 16{sup o} inclination of the AFB{sub 1} moiety with respect to the guanine. A binary (Dpo4-DNA) structure with an AFB{sub 1}-FAPY adducted template:primer also maintains 5'-intercalation of the AFB{sub 1} moiety. The {beta}-deoxyribose anomer is observed. Rotation about the FAPY C5-N{sup 5} bond orients the bond between N{sup 5} and C8 of the AFB{sub 1} moiety out of plane in the 5'-direction, with respect to the FAPY base. The formamide group extends in the 3'-direction. This improves stacking of the AFB{sub 1} moiety above the 5'-face of the FAPY base, as compared to the AFB{sub 1}-N7-dG adduct. Ternary structures with AFB{sub 1}-{beta}-FAPY adducted template:primers show correct vs incorrect insertion of dATP vs dTTP opposite the 5'-template neighbor dT from a primed AFB{sub 1}-{beta}-FAPY:dC pair. For dATP, the oxygen atom of the FAPY formamide group participates in a water-mediated hydrogen bond with Arg332. The insertion of dTTP yields a structure similar to that observed for the AFB{sub 1}-N7-dG adduct. The differential accommodation of these AFB{sub 1} adducts within the active site may, in part, modulate lesion bypass.« less

Safety and Efficacy of Topical Chitogel- Deferiprone-Gallium Protoporphyrin in Sheep Model

PubMed Central

Ooi, Mian L.; Richter, Katharina; Drilling, Amanda J.; Thomas, Nicky; Prestidge, Clive A.; James, Craig; Moratti, Stephen; Vreugde, Sarah; Psaltis, Alkis J.; Wormald, Peter-John

2018-01-01

Objectives: Increasing antimicrobial resistance has presented new challenges to the treatment of recalcitrant chronic rhinosinusitis fuelling a continuous search for novel antibiofilm agents. This study aimed to assess the safety and efficacy of Chitogel (Chitogel®, Wellington New Zealand) combined with novel antibiofilm agents Deferiprone and Gallium Protoporphyrin (CG-DG) as a topical treatment against S. aureus biofilms in vivo. Methods: To assess safety, 8 sheep were divided into two groups of 7 day treatments (n = 8 sinuses per treatment); (1) Chitogel (CG) with twice daily saline flush, and (2) CG-DG gel with twice daily saline flush. Tissue morphology was analyzed using histology and scanning electron microscopy (SEM). To assess efficacy we used a S. aureus sheep sinusitis model. Fifteen sheep were divided into three groups of 7 day treatments (n = 10 sinuses per treatment); (1) twice daily saline flush (NT), (2) Chitogel (CG) with twice daily saline flush, and (3) CG-DG gel with twice daily saline flush. Biofilm biomass across all groups was compared using LIVE/DEAD BacLight stain and confocal scanning laser microscopy. Results: Safety study showed no cilia denudation on scanning electron microscopy and no change in sinus mucosa histopathology when comparing CG-DG to CG treated sheep. COMSTAT2 assessment of biofilm biomass showed a significant reduction in CG-DG treated sheep compared to NT controls. Conclusion: Results indicate that CG-DG is safe and effective against S. aureus biofilms in a sheep sinusitis model and could represent a viable treatment option in the clinical setting.

Background and stimulus-induced patterns of high metabolic activity in the visual cortex (area 17) of the squirrel and macaque monkey

DOE Office of Scientific and Technical Information (OSTI.GOV)

Humphrey, A.L.; Hendrickson, A.E.

1983-02-01

The authors have used 2-deoxy-D-(/sup 14/C)glucose (2-DG) autoradiography and cytochrome oxidase histochemistry to examine background and stimulus-induced patterns of metabolic activity in monkey striate cortex. In squirrel monkeys (Saimiri sciureus) that binocularly or monocularly viewed diffuse white light or binocularly viewed bars of many orientations and spatial frequencies, 2-DG consumption was not uniform across the cortex but consisted of regularly spaced radial zones of high uptake. The cytochrome oxidase stain in these animals also revealed patches of high metabolism which coincided with the 2-DG patches. Squirrel monkeys binocularly viewing vertical stripes showed parallel bands of increased 2-DG uptake in themore » cortex, while the cytochrome label in these animals remained patchy. In macaque (Macaca nemestrina) monkeys, binocular stimulation with many orientations and spatial frequencies produced radial zones of high 2-DG uptake. When viewed tangentially, these zones formed a dots-in-rows pattern with a spacing of 350 X 500 microns; cytochrome oxidase staining produced an identical pattern. Macaca differed from Saimiri in that monocular stimulation labeled alternate rows. These results indicate that there are radial zones of high background metabolism across squirrel and macaque monkey striate cortex. In Saimiri these zones do not appear to be related to an eye dominance system, while in Macaca they do. The presence of these zones of high metabolism may complicate the interpretation of 2-DG autoradiographs that result from specific visual stimuli.« less

Nonlinear dynamics in the perceptual grouping of connected surfaces.

PubMed

Hock, Howard S; Schöner, Gregor

2016-09-01

Evidence obtained using the dynamic grouping method has shown that the grouping of an object's connected surfaces has properties characteristic of a nonlinear dynamical system. When a surface's luminance changes, one of its boundaries is perceived moving across the surface. The direction of this dynamic grouping (DG) motion indicates which of two flanking surfaces has been grouped with the changing surface. A quantitative measure of overall grouping strength (affinity) for adjacent surfaces is provided by the frequency of DG motion perception in directions promoted by the grouping variables. It was found that: (1) variables affecting surface grouping for three-surface objects evolve over time, settling at stable levels within a single fixation, (2) how often DG motion is perceived when a surface's luminance is perturbed (changed) depends on the pre-perturbation affinity state of the surface grouping, (3) grouping variables promoting the same surface grouping combine cooperatively and nonlinearly (super-additively) in determining the surface grouping's affinity, (4) different DG motion directions during different trials indicate that surface grouping can be bistable, which implies that inhibitory interactions have stabilized one of two alternative surface groupings, and (5) when alternative surface groupings have identical affinity, stochastic fluctuations can break the symmetry and inhibitory interactions can then stabilize one of the surface groupings, providing affinity levels are not too high (which results in bidirectional DG motion). A surface-grouping network is proposed within which boundaries vary in salience. Low salience or suppressed boundaries instantiate surface grouping, and DG motion results from changes in boundary salience. Copyright © 2015 Elsevier Ltd. All rights reserved.