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Sample records for double auction mechanism

  1. A Greedy Double Auction Mechanism for Grid Resource Allocation

    NASA Astrophysics Data System (ADS)

    Ding, Ding; Luo, Siwei; Gao, Zhan

    To improve the resource utilization and satisfy more users, a Greedy Double Auction Mechanism(GDAM) is proposed to allocate resources in grid environments. GDAM trades resources at discriminatory price instead of uniform price, reflecting the variance in requirements for profits and quantities. Moreover, GDAM applies different auction rules to different cases, over-demand, over-supply and equilibrium of demand and supply. As a new mechanism for grid resource allocation, GDAM is proved to be strategy-proof, economically efficient, weakly budget-balanced and individual rational. Simulation results also confirm that GDAM outperforms the traditional one on both the total trade amount and the user satisfaction percentage, specially as more users are involved in the auction market.

  2. Statistical theory of the continuous double auction

    NASA Astrophysics Data System (ADS)

    Smith, Eric; Doyne Farmer, J.; Gillemot, László; Krishnamurthy, Supriya

    2003-12-01

    Most modern financial markets use a continuous double auction mechanism to store and match orders and facilitate trading. In this paper we develop a microscopic dynamical statistical model for the continuous double auction under the assumption of IID random order flow, and analyse it using simulation, dimensional analysis, and theoretical tools based on mean field approximations. The model makes testable predictions for basic properties of markets, such as price volatility, the depth of stored supply and demand versus price, the bid-ask spread, the price impact function, and the time and probability of filling orders. These predictions are based on properties of order flow and the limit order book, such as share volume of market and limit orders, cancellations, typical order size, and tick size. Because these quantities can all be measured directly there are no free parameters. We show that the order size, which can be cast as a non-dimensional granularity parameter, is in most cases a more significant determinant of market behaviour than tick size. We also provide an explanation for the observed highly concave nature of the price impact function. On a broader level, this work suggests how stochastic models based on zero intelligence agents may be useful to probe the structure of market institutions. Like the model of perfect rationality, a stochastic zero intelligence model can be used to make strong predictions based on a compact set of assumptions, even if these assumptions are not fully believable.

  3. Poisson-process generalization for the trading waiting-time distribution in a double-auction mechanism

    NASA Astrophysics Data System (ADS)

    Cincotti, Silvano; Ponta, Linda; Raberto, Marco; Scalas, Enrico

    2005-05-01

    In this paper, empirical analyses and computational experiments are presented on high-frequency data for a double-auction (book) market. Main objective of the paper is to generalize the order waiting time process in order to properly model such empirical evidences. The empirical study is performed on the best bid and best ask data of 7 U.S. financial markets, for 30-stock time series. In particular, statistical properties of trading waiting times have been analyzed and quality of fits is evaluated by suitable statistical tests, i.e., comparing empirical distributions with theoretical models. Starting from the statistical studies on real data, attention has been focused on the reproducibility of such results in an artificial market. The computational experiments have been performed within the Genoa Artificial Stock Market. In the market model, heterogeneous agents trade one risky asset in exchange for cash. Agents have zero intelligence and issue random limit or market orders depending on their budget constraints. The price is cleared by means of a limit order book. The order generation is modelled with a renewal process. Based on empirical trading estimation, the distribution of waiting times between two consecutive orders is modelled by a mixture of exponential processes. Results show that the empirical waiting-time distribution can be considered as a generalization of a Poisson process. Moreover, the renewal process can approximate real data and implementation on the artificial stocks market can reproduce the trading activity in a realistic way.

  4. Statistical Mechanics of Combinatorial Auctions

    NASA Astrophysics Data System (ADS)

    Galla, Tobias; Leone, Michele; Marsili, Matteo; Sellitto, Mauro; Weigt, Martin; Zecchina, Riccardo

    2006-09-01

    Combinatorial auctions are formulated as frustrated lattice gases on sparse random graphs, allowing the determination of the optimal revenue by methods of statistical physics. Transitions between computationally easy and hard regimes are found and interpreted in terms of the geometric structure of the space of solutions. We introduce an iterative algorithm to solve intermediate and large instances, and discuss competing states of optimal revenue and maximal number of satisfied bidders. The algorithm can be generalized to the hard phase and to more sophisticated auction protocols.

  5. Understanding Financial Market States Using an Artificial Double Auction Market.

    PubMed

    Yim, Kyubin; Oh, Gabjin; Kim, Seunghwan

    2016-01-01

    The ultimate value of theories describing the fundamental mechanisms behind asset prices in financial systems is reflected in the capacity of such theories to understand these systems. Although the models that explain the various states of financial markets offer substantial evidence from the fields of finance, mathematics, and even physics, previous theories that attempt to address the complexities of financial markets in full have been inadequate. We propose an artificial double auction market as an agent-based model to study the origin of complex states in financial markets by characterizing important parameters with an investment strategy that can cover the dynamics of the financial market. The investment strategies of chartist traders in response to new market information should reduce market stability based on the price fluctuations of risky assets. However, fundamentalist traders strategically submit orders based on fundamental value and, thereby stabilize the market. We construct a continuous double auction market and find that the market is controlled by the proportion of chartists, Pc. We show that mimicking the real state of financial markets, which emerges in real financial systems, is given within the range Pc = 0.40 to Pc = 0.85; however, we show that mimicking the efficient market hypothesis state can be generated with values less than Pc = 0.40. In particular, we observe that mimicking a market collapse state is created with values greater than Pc = 0.85, at which point a liquidity shortage occurs, and the phase transition behavior is described at Pc = 0.85.

  6. Understanding Financial Market States Using an Artificial Double Auction Market

    PubMed Central

    2016-01-01

    The ultimate value of theories describing the fundamental mechanisms behind asset prices in financial systems is reflected in the capacity of such theories to understand these systems. Although the models that explain the various states of financial markets offer substantial evidence from the fields of finance, mathematics, and even physics, previous theories that attempt to address the complexities of financial markets in full have been inadequate. We propose an artificial double auction market as an agent-based model to study the origin of complex states in financial markets by characterizing important parameters with an investment strategy that can cover the dynamics of the financial market. The investment strategies of chartist traders in response to new market information should reduce market stability based on the price fluctuations of risky assets. However, fundamentalist traders strategically submit orders based on fundamental value and, thereby stabilize the market. We construct a continuous double auction market and find that the market is controlled by the proportion of chartists, Pc. We show that mimicking the real state of financial markets, which emerges in real financial systems, is given within the range Pc = 0.40 to Pc = 0.85; however, we show that mimicking the efficient market hypothesis state can be generated with values less than Pc = 0.40. In particular, we observe that mimicking a market collapse state is created with values greater than Pc = 0.85, at which point a liquidity shortage occurs, and the phase transition behavior is described at Pc = 0.85. PMID:27031110

  7. From Walras’ auctioneer to continuous time double auctions: a general dynamic theory of supply and demand

    NASA Astrophysics Data System (ADS)

    Donier, J.; Bouchaud, J.-P.

    2016-12-01

    In standard Walrasian auctions, the price of a good is defined as the point where the supply and demand curves intersect. Since both curves are generically regular, the response to small perturbations is linearly small. However, a crucial ingredient is absent of the theory, namely transactions themselves. What happens after they occur? To answer the question, we develop a dynamic theory for supply and demand based on agents with heterogeneous beliefs. When the inter-auction time is infinitely long, the Walrasian mechanism is recovered. When transactions are allowed to happen in continuous time, a peculiar property emerges: close to the price, supply and demand vanish quadratically, which we empirically confirm on the Bitcoin. This explains why price impact in financial markets is universally observed to behave as the square root of the excess volume. The consequences are important, as they imply that the very fact of clearing the market makes prices hypersensitive to small fluctuations.

  8. Auction Mechanism to Allocate Air Traffic Control Slots

    NASA Technical Reports Server (NTRS)

    Raffarin, Marianne

    2003-01-01

    This article deals with an auction mechanism for airspace slots, as a means of solving the European airspace congestion problem. A disequilibrium, between Air Traffic Control (ATC) services supply and ATC services demand are at the origin of almost one fourth of delays in the air transport industry in Europe. In order to tackle this congestion problem, we suggest modifying both pricing and allocation of ATC services, by setting up an auction mechanism. Objects of the auction will be the right for airlines to cross a part of the airspace, and then to benefit from ATC services over a period corresponding to the necessary time for the crossing. Allocation and payment rules have to be defined according to the objectives of this auction. The auctioneer is the public authority in charge of ATC services, whose aim is to obtain an efficient allocation. Therefore, the social value will be maximized. Another objective is to internalize congestion costs. To that end, we apply the principle of Clarke-Groves mechanism auction: each winner has to pay the externalities imposed on other bidders. The complex context of ATC leads to a specific design for this auction.

  9. Adaptive Sniping for Volatile and Stable Continuous Double Auction Markets

    NASA Astrophysics Data System (ADS)

    Toft, I. E.; Bagnall, A. J.

    This paper introduces a new adaptive sniping agent for the Continuous Double Auction. We begin by analysing the performance of the well known Kaplan sniper in two extremes of market conditions. We generate volatile and stable market conditions using the well known Zero Intelligence-Constrained agent and a new zero-intelligence agent Small Increment (SI). ZI-C agents submit random but profitable bids/offers and cause high volatility in prices and individual trader performance. Our new zero-intelligence agent, SI, makes small random adjustments to the outstanding bid/offer and hence is more cautious than ZI-C. We present results for SI in self-play and then analyse Kaplan in volatile and stable markets. We demonstrate that the non-adaptive Kaplan sniper can be configured to suit either market conditions, but no single configuration is performs well across both market types. We believe that in a dynamic auction environment where current or future market conditions cannot be predicted a viable sniping strategy should adapt its behaviour to suit prevailing market conditions. To this end, we propose the Adaptive Sniper (AS) agent for the CDA. AS traders classify sniping opportunities using a statistical model of market activity and adjust their classification thresholds using a Widrow-Hoff adapted search. Our AS agent requires little configuration, and outperforms the original Kaplan sniper in volatile and stable markets, and in a mixed trader type scenario that includes adaptive strategies from the literature.

  10. Modeling and simulation of a double auction artificial financial market

    NASA Astrophysics Data System (ADS)

    Raberto, Marco; Cincotti, Silvano

    2005-09-01

    We present a double-auction artificial financial market populated by heterogeneous agents who trade one risky asset in exchange for cash. Agents issue random orders subject to budget constraints. The limit prices of orders may depend on past market volatility. Limit orders are stored in the book whereas market orders give immediate birth to transactions. We show that fat tails and volatility clustering are recovered by means of very simple assumptions. We also investigate two important stylized facts of the limit order book, i.e., the distribution of waiting times between two consecutive transactions and the instantaneous price impact function. We show both theoretically and through simulations that if the order waiting times are exponentially distributed, even trading waiting times are also exponentially distributed.

  11. Ergodic Transition in a Simple Model of the Continuous Double Auction

    PubMed Central

    Radivojević, Tijana; Anselmi, Jonatha; Scalas, Enrico

    2014-01-01

    We study a phenomenological model for the continuous double auction, whose aggregate order process is equivalent to two independent queues. The continuous double auction defines a continuous-time random walk for trade prices. The conditions for ergodicity of the auction are derived and, as a consequence, three possible regimes in the behavior of prices and logarithmic returns are observed. In the ergodic regime, prices are unstable and one can observe a heteroskedastic behavior in the logarithmic returns. On the contrary, non-ergodicity triggers stability of prices, even if two different regimes can be seen. PMID:24558377

  12. Alternative Salary Auction Mechanisms for the Navy: An Experimental Program

    DTIC Science & Technology

    2007-12-01

    auctions transfer the most surplus value to the Navy. Equity is fairness among sailors, and may mean equal pay or equal benefit (surplus)3. No...values range from $40,000 to $80,000 – Each value in range equally likely – Rounded to nearest $1000 8 Willingness to Pay (WTP) • Maximum a company is...test the impact of bidding behavior on two matching mechanisms proposed by prior research for use in the U.S. Navy’s Assignment Incentive Pay (AIP

  13. A False-name-Proof Double Auction Protocol for Arbitrary Evaluation Values

    NASA Astrophysics Data System (ADS)

    Sakurai, Yuko; Yokoo, Makoto

    We develop a new false-name-proof double auction protocol called the Generalized Threshold Price Double auction (GTPD) protocol. False-name-proofness generalizes strategy-proofness by incorporating the possibility of false-name bids, e.g., bids submitted using multiple e-mail addresses. An existing protocol called TPD protocol is false-name-proof but can handle only the cases where marginal utilities of each agent always decrease, while our new GTPD protocol can handle arbitrary evaluation values. When marginal utilities can increase, some bids cannot be divided into a single unit (e.g., an all-or-nothing bid). Due to the existence of such indivisible bids, meeting supply/demand becomes difficult. Furthermore, a seller/buyer can submit a false-name-bid by pretending to be a potential buyer/seller to manipulate allocations and payments. In the GTPD protocol, the auctioneer is required to absorb the supply-demand imbalance up to a given upper-bound. Also, the GTPD incorporate a new false-name-proof one-sided auction protocol that is guaranteed to sell/buy a certain number of units. Simulation results show that when the threshold price is set appropriately, this protocol can obtain a good social surplus, and the number of absorbed units is much smaller than the given upper-bound.

  14. Learning Based Bidding Strategy for HVAC Systems in Double Auction Retail Energy Markets

    SciTech Connect

    Sun, Yannan; Somani, Abhishek; Carroll, Thomas E.

    2015-07-01

    In this paper, a bidding strategy is proposed using reinforcement learning for HVAC systems in a double auction market. The bidding strategy does not require a specific model-based representation of behavior, i.e., a functional form to translate indoor house temperatures into bid prices. The results from reinforcement learning based approach are compared with the HVAC bidding approach used in the AEP gridSMART® smart grid demonstration project and it is shown that the model-free (learning based) approach tracks well the results from the model-based behavior. Successful use of model-free approaches to represent device-level economic behavior may help develop similar approaches to represent behavior of more complex devices or groups of diverse devices, such as in a building. Distributed control requires an understanding of decision making processes of intelligent agents so that appropriate mechanisms may be developed to control and coordinate their responses, and model-free approaches to represent behavior will be extremely useful in that quest.

  15. Investor structure and the price-volume relationship in a continuous double auction market: An agent-based modeling perspective

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Bi, Zhengzheng; Shen, Dehua

    2017-02-01

    This paper investigates the impact of investor structure on the price-volume relationship by simulating a continuous double auction market. Connected with the underlying mechanisms of the price-volume relationship, i.e., the Mixture of Distribution Hypothesis (MDH) and the Sequential Information Arrival Hypothesis (SIAH), the simulation results show that: (1) there exists a strong lead-lag relationship between the return volatility and trading volume when the number of informed investors is close to the number of uninformed investors in the market; (2) as more and more informed investors entering the market, the lead-lag relationship becomes weaker and weaker, while the contemporaneous relationship between the return volatility and trading volume becomes more prominent; (3) when the informed investors are in absolute majority, the market can achieve the new equilibrium immediately. Therefore, we can conclude that the investor structure is a key factor in affecting the price-volume relationship.

  16. Mechanism Design for Multi-slot Ads Auction in Sponsored Search Markets

    NASA Astrophysics Data System (ADS)

    Deng, Xiaotie; Sun, Yang; Yin, Ming; Zhou, Yunhong

    In this paper, we study pricing models for multi-slot advertisements, where advertisers can bid to place links to their sales webpages at one or multiple slots on a webpage, called the multi-slot AD auction problem. We develop and analyze several important mechanisms, including the VCG mechanism for multi-slot ads auction, the optimal social welfare solution, as well as two weighted GSP-like protocols (mixed and hybrid). Furthermore, we consider that forward-looking Nash equilibrium and prove its existence in the weighted GSP-like pricing protocols.

  17. Evaluation of Aviation Career Pay Incentives Among the Naval Aviation Enterprise Utilizing Auction Mechanisms

    DTIC Science & Technology

    2015-03-01

    Navy Aviation, we analyzed the impact that market - based mechanisms would have on quantity, quality, and cost for retained naval aviators. Using these...FY-2013 ACCP program. Om research shows that a market -based auction could include improvements in cost, quality, and particularly quantity of...current bonus system. Incorporating survey results from 2,316 naval officers across Navy Aviation, we analyzed the impact that market -based mechanisms

  18. Emergence of Cooperative Long-Term Market Loyalty in Double Auction Markets

    PubMed Central

    Alorić, Aleksandra; Sollich, Peter; McBurney, Peter; Galla, Tobias

    2016-01-01

    Loyal buyer-seller relationships can arise by design, e.g. when a seller tailors a product to a specific market niche to accomplish the best possible returns, and buyers respond to the dedicated efforts the seller makes to meet their needs. We ask whether it is possible, instead, for loyalty to arise spontaneously, and in particular as a consequence of repeated interaction and co-adaptation among the agents in a market. We devise a stylized model of double auction markets and adaptive traders that incorporates these features. Traders choose where to trade (which market) and how to trade (to buy or to sell) based on their previous experience. We find that when the typical scale of market returns (or, at fixed scale of returns, the intensity of choice) become higher than some threshold, the preferred state of the system is segregated: both buyers and sellers are segmented into subgroups that are persistently loyal to one market over another. We characterize the segregated state analytically in the limit of large markets: it is stabilized by some agents acting cooperatively to enable trade, and provides higher rewards than its unsegregated counterpart both for individual traders and the population as a whole. PMID:27120473

  19. Emergence of Cooperative Long-Term Market Loyalty in Double Auction Markets.

    PubMed

    Alorić, Aleksandra; Sollich, Peter; McBurney, Peter; Galla, Tobias

    2016-01-01

    Loyal buyer-seller relationships can arise by design, e.g. when a seller tailors a product to a specific market niche to accomplish the best possible returns, and buyers respond to the dedicated efforts the seller makes to meet their needs. We ask whether it is possible, instead, for loyalty to arise spontaneously, and in particular as a consequence of repeated interaction and co-adaptation among the agents in a market. We devise a stylized model of double auction markets and adaptive traders that incorporates these features. Traders choose where to trade (which market) and how to trade (to buy or to sell) based on their previous experience. We find that when the typical scale of market returns (or, at fixed scale of returns, the intensity of choice) become higher than some threshold, the preferred state of the system is segregated: both buyers and sellers are segmented into subgroups that are persistently loyal to one market over another. We characterize the segregated state analytically in the limit of large markets: it is stabilized by some agents acting cooperatively to enable trade, and provides higher rewards than its unsegregated counterpart both for individual traders and the population as a whole.

  20. Efficient Nash Equilibrium Resource Allocation Based on Game Theory Mechanism in Cloud Computing by Using Auction.

    PubMed

    Nezarat, Amin; Dastghaibifard, G H

    2015-01-01

    One of the most complex issues in the cloud computing environment is the problem of resource allocation so that, on one hand, the cloud provider expects the most profitability and, on the other hand, users also expect to have the best resources at their disposal considering the budget constraints and time. In most previous work conducted, heuristic and evolutionary approaches have been used to solve this problem. Nevertheless, since the nature of this environment is based on economic methods, using such methods can decrease response time and reducing the complexity of the problem. In this paper, an auction-based method is proposed which determines the auction winner by applying game theory mechanism and holding a repetitive game with incomplete information in a non-cooperative environment. In this method, users calculate suitable price bid with their objective function during several round and repetitions and send it to the auctioneer; and the auctioneer chooses the winning player based the suggested utility function. In the proposed method, the end point of the game is the Nash equilibrium point where players are no longer inclined to alter their bid for that resource and the final bid also satisfies the auctioneer's utility function. To prove the response space convexity, the Lagrange method is used and the proposed model is simulated in the cloudsim and the results are compared with previous work. At the end, it is concluded that this method converges to a response in a shorter time, provides the lowest service level agreement violations and the most utility to the provider.

  1. A Centralized Auction Mechanism for the Disability and Survivors Insurance in Chile

    NASA Astrophysics Data System (ADS)

    Reyes H., Gonzalo

    As part of the pension reform recently approved in Chile, the government introduced a centralized auction mechanism to provide the Disability and Survivors (D&S) Insurance that covers recent contributors among the more than 8 million participants in the mandatory private pension system. This paper is intended as a case study presenting the main distortions found in the decentralized operation of the system that led to this reform and the challenges faced when designing a competitive auction mechanism to be implemented jointly by the Pension Fund Managers (AFP). In a typical bilateral contract the AFP retained much of the risk and the Insurance Company acted in practice as a reinsurer. The process to hire this contract was not competitive and colligated companies ended up providing the service. Several distortions affected competition in the market through incentives to cream-skim members by AFPs (since they bear most of the risk) or efforts to block disability claims. Since the price of this insurance is hidden in the fees charged by AFPs for the administration of individual accounts and pension funds there was lack of price transparency. Since new AFPs have no history of members’ disability and mortality profile the insurance contract acted as a barrier to entry in the market of AFP services, especially when D&S insurance costs reached 50% of total costs. Cross-subsidies between members of the same AFP, inefficient risk pooling (due to pooling occurring at the AFP rather than at the system level) and regulatory arbitrage, since AFPs provided insurance not being regulated as an insurance company, were also present. A centralized auction mechanism solves these market failures, but also gives raise to new challenges, such as how to design a competitive auction that attracts participation and deters collusion. Design features that were incorporated in the regulation to tackle these issues, such as dividing coverage into predefined percentage blocks, are presented

  2. A Hierarchical Auction-Based Mechanism for Real-Time Resource Allocation in Cloud Robotic Systems.

    PubMed

    Wang, Lujia; Liu, Ming; Meng, Max Q-H

    2017-02-01

    Cloud computing enables users to share computing resources on-demand. The cloud computing framework cannot be directly mapped to cloud robotic systems with ad hoc networks since cloud robotic systems have additional constraints such as limited bandwidth and dynamic structure. However, most multirobotic applications with cooperative control adopt this decentralized approach to avoid a single point of failure. Robots need to continuously update intensive data to execute tasks in a coordinated manner, which implies real-time requirements. Thus, a resource allocation strategy is required, especially in such resource-constrained environments. This paper proposes a hierarchical auction-based mechanism, namely link quality matrix (LQM) auction, which is suitable for ad hoc networks by introducing a link quality indicator. The proposed algorithm produces a fast and robust method that is accurate and scalable. It reduces both global communication and unnecessary repeated computation. The proposed method is designed for firm real-time resource retrieval for physical multirobot systems. A joint surveillance scenario empirically validates the proposed mechanism by assessing several practical metrics. The results show that the proposed LQM auction outperforms state-of-the-art algorithms for resource allocation.

  3. Efficient Nash Equilibrium Resource Allocation Based on Game Theory Mechanism in Cloud Computing by Using Auction

    PubMed Central

    Nezarat, Amin; Dastghaibifard, GH

    2015-01-01

    One of the most complex issues in the cloud computing environment is the problem of resource allocation so that, on one hand, the cloud provider expects the most profitability and, on the other hand, users also expect to have the best resources at their disposal considering the budget constraints and time. In most previous work conducted, heuristic and evolutionary approaches have been used to solve this problem. Nevertheless, since the nature of this environment is based on economic methods, using such methods can decrease response time and reducing the complexity of the problem. In this paper, an auction-based method is proposed which determines the auction winner by applying game theory mechanism and holding a repetitive game with incomplete information in a non-cooperative environment. In this method, users calculate suitable price bid with their objective function during several round and repetitions and send it to the auctioneer; and the auctioneer chooses the winning player based the suggested utility function. In the proposed method, the end point of the game is the Nash equilibrium point where players are no longer inclined to alter their bid for that resource and the final bid also satisfies the auctioneer’s utility function. To prove the response space convexity, the Lagrange method is used and the proposed model is simulated in the cloudsim and the results are compared with previous work. At the end, it is concluded that this method converges to a response in a shorter time, provides the lowest service level agreement violations and the most utility to the provider. PMID:26431035

  4. Reputation mechanism: From resolution for truthful online auctions to the model of optimal one-gambler problem

    SciTech Connect

    Bradonjic, Milan

    2009-01-01

    In this paper we study reputation mechanisms, and show how the notion of reputation can help us in building truthful online auction mechanisms. From the mechanism design prospective, we derive the conditions on and design a truthful online auction mechanism. Moreover, in the case when some agents may lay or cannot have the real knowledge about the other agents reputations, we derive the resolution of the auction, such that the mechanism is truthful. Consequently, we move forward to the optimal one-gambler/one-seller problem, and explain how that problem is refinement of the previously discussed online auction design in the presence of reputation mechanism. In the setting of the optimal one-gambler problem, we naturally rise and solve the specific question: What is an agent's optimal strategy, in order to maximize his revenue? We would like to stress that our analysis goes beyond the scope, which game theory usually discusses under the notion of reputation. We model one-player games, by introducing a new parameter (reputation), which helps us in predicting the agent's behavior, in real-world situations, such as, behavior of a gambler, real-estate dealer, etc.

  5. Three essays on auction markets

    NASA Astrophysics Data System (ADS)

    Shunda, Nicholas James

    This dissertation contains a series of theoretical investigations of auction markets. The essays it contains cover wholesale electricity markets, a popular selling mechanism on eBay, and supplier entry into multi-unit procurement auctions. The study in Chapter 1 compares the procurement cost-minimizing and productive efficiency performance of the auction mechanism used by independent system operators in wholesale electricity auction markets in the U.S. with that of a proposed alternative. The current practice allocates energy contracts as if the auction featured a discriminatory final payment method when, in fact, the markets are uniform price auctions. The proposed alternative explicitly accounts for the market-clearing price during the allocation phase. We find that the proposed alternative largely outperforms the current practice on the basis of procurement costs in the context of simple auction markets featuring both day-ahead and real-time auctions and that the procurement cost advantage of the alternative is complete when we simulate the effects of increased competition. We also find that a tradeoff between the objectives of procurement cost minimization and productive efficiency emerges in our simple auction markets and persists in the face of increased competition. The study in Chapter 2 considers a possible rationale for an auction with a buy price. In an auction with a buy price, the seller provides bidders with an option to end the auction early by accepting a transaction at a posted price. The "Buy-It-Now" option on eBay is a leading example of an auction with a buy price. The study develops a model of an auction with a buy price in which bidders use the auction's reserve price and buy price to formulate a reference price. The model both explains why a revenue-maximizing seller would want to augment her auction with a buy price and demonstrates that the seller sets a higher reserve price when she can affect the bidders' reference price through the

  6. Auctioning Airport Slots?

    NASA Technical Reports Server (NTRS)

    Gruyer, Nicolas; Lenoir, Nathalie

    2003-01-01

    The current allocation of slots on congested European airports constitutes an obstacle to the effective liberalisation of air transportation undertaken in Europe. With a view to favouring effluent slot utilisation and competition, as is the goal of the Euopean commission, we propose to use a market mechanism, based on temporary" utilisation licences. In order to allocate those licences, we propose and describe an iterated combinatorial auction mechanism where a percentage of licences would be reallocated each season. A secondary market would also be set up in order to reallocate slots during a season. Since a combinatorial auction involve a complex optimisation procedure, we describe how it can be made to work in the case of auctions.

  7. Evaluation of PersianCAT Agent's Accepting Policy in Continuous Double Auction, Participant in CAT 2007 Competition

    NASA Astrophysics Data System (ADS)

    Honari, Sina; Fos-Hati, Amin; Ebadi, Mojtaba; Gomrokchi, Maziar

    As there is a growing tendency towards online auctions, online Multi Agent Systems for economic activities like stock exchanges is more in demand. CAT (CATallactics) competition has produced a great opportunity for researchers since 2007 to put their theories into practice in a real-time economic-based competition, combining traders and brokers. As one of participants, we evaluated our new accepting policy by putting it to challenge. In this paper we give a general overview of one of our policies in the market.

  8. ATHLETE : Double Auger Anchoring Mechanism

    NASA Technical Reports Server (NTRS)

    Shin, Joseph

    2011-01-01

    The All-Terrain Hex-Legged Extra-Terrestrial Explorer (ATHLETE) is a six-limbed robot designed to support surface explorations on Near Earth Objects, the Moon and Mars. ATHLETE can carry large payloads on its top deck and can carry a fully equipped pressurized habitat in low gravity. The robot has wheels on each of its six articulated limbs, allowing it to actively conform to terrain while driving and to walk when driving is impractical. With the use of a tool adapter, ATHLETE limbs can be equipped with end effectors to support various mission objectives. For work on Near Earth Objects and other microgravity environments, an anchoring mechanism is needed to keep the ATHLETE from floating off the surface. My goal for this spring session at JPL was to design and build a counter rotating, double auger, anchoring mechanism. The mechanism mates to the tool adapter and is driven off the wheel motor. The double auger anchoring mechanism will be tested in a regolith simulant that will determine the uplift capacity of the anchoring mechanism.

  9. Effects of Suboptimal Bidding in Combinatorial Auctions

    NASA Astrophysics Data System (ADS)

    Schneider, Stefan; Shabalin, Pasha; Bichler, Martin

    Though the VCG auction assumes a central place in the mechanism design literature, there are a number of reasons for favoring iterative combinatorial auction designs. Several promising ascending auction formats have been developed throughout the past few years based on primal-dual and subgradient algorithms and linear programming theory. Prices are interpreted as a feasible dual solution and the provisional allocation is interpreted as a feasible primal solution. iBundle( 3) (Parkes and Ungar 2000), dVSV (de Vries et al. 2007) and the Ascending Proxy auction (Ausubel and Milgrom 2002) result in VCG payoffs when the coalitional value function satisfies the buyer submodularity condition and bidders bid straightforward, which is an expost Nash equilibrium in that case. iBEA and CreditDebit auctions (Mishra and Parkes 2007) do not even require the buyer submodularity condition and achieve the same properties for general valuations. In many situations, however, one cannot assume bidders to bid straightforward and it is not clear from the theory how these non-linear personalized price auctions (NLPPAs) perform in this case. Robustness of auctions with respect to different bidding behavior is therefore a critical issue for any application. We have conducted a large number of computational experiments to analyze the performance of NLPPA designs with respect to different bidding strategies and different valuation models. We compare the results of NLPPAs to those of the VCG auction and those of iterative combinatorial auctions with approximate linear prices, such as ALPS (Bichler et al. 2009) and the Combinatorial Clock auction (Porter et al. 2003).

  10. Combinatorial auction design

    PubMed Central

    Porter, David; Rassenti, Stephen; Roopnarine, Anil; Smith, Vernon

    2003-01-01

    Combinatorial auctions allow for more expressive bidding in which participants can submit package bids with logical constraints that limit allowable outcomes. This type of auction can be useful when participants' values are complementary or when participants have production and financial constraints. However, combinatorial auctions are currently rare in practice. The main problems confronted in implementing these auctions are that they have computational uncertainty (i.e., there is no guarantee that the winning bids for such an auction can be found in a “reasonable” amount of time when the number of bidders and items becomes larger) and that the auction is cognitively complex and can lead participants to pursue perverse bidding strategies. This article describes a type of combinatorial auction that, during laboratory testing, eliminated these problems and produced extremely efficient outcomes. PMID:12893875

  11. Auction-based Security Game for Multiuser Cooperative Networks

    NASA Astrophysics Data System (ADS)

    Wang, An; Cai, Yueming; Yang, Wendong; Cheng, Yunpeng

    2013-04-01

    In this paper, we develop an auction-based algorithm to allocate the relay power efficiently to improve the system secrecy rate in a cooperative network, where several source-destination pairs and one cooperative relay are involved. On the one hand, the cooperative relay assists these pairs to transmit under a peak power constraint. On the other hand, the relay is untrusty and is also a passive eavesdropper. The whole auction process is completely distributed and no instantaneous channel state information exchange is needed. We also prove the existence and uniqueness of the Nash Equilibrium (NE) for the proposed power auction game. Moreover, the Pareto optimality is also validated. Simulation results show that our proposed auction-based algorithm can effectively improve the system secrecy rate. Besides, the proposed auction-based algorithm can converge to the unique NE point within a finite number of iterations. More interestingly, we also find that the proposed power auction mechanism is cheat-proof.

  12. Double-Swivel Mechanism For Reliable Release

    NASA Technical Reports Server (NTRS)

    King, Guy L.; Schneider, William C.

    1990-01-01

    Double-swivel toggle mechanism releases large, heavy objects reliably. Double-swiveling action of mechanism ensures it clears restraining pins upon release. Pins retain toggle and its load. If pin fails to withdraw at designated time for releasing payload, toggle swivels about its upper ball, and ring swivels about lower ball so ring flange clears failed pin. Double-swivel action ensures disengagement even it two pins fail to withdraw.

  13. An Auction-Based Spectrum Leasing Mechanism for Mobile Macro-Femtocell Networks of IoT.

    PubMed

    Chen, Xin; Xing, Lei; Qiu, Tie; Li, Zhuo

    2017-02-16

    The Internet of Things (IoT) is a vision of the upcoming society. It can provide pervasive communication between two or more entities using 4G-LTE (Long Term Evolution) communication technology. In 4G-LTE networks, there are two important problems: helping manage the spectrum demands of IoT devices and achieving much more revenue with the limited resource. This paper proposes a pricing framework to investigate the spectrum leasing in mobile heterogeneous networks with single macrocell and multiple femtocells. We modeled the leasing procedure between the macrocell service provider (MSP) and femtocell holders (FHs) as an auction to motivate the MSP to lease its spectrum resource. All FHs act as the bidders, and the monopolist MSP acts as the auctioneer. In the auction, FHs submit their bids to rent the spectrum resource so that they can make a profit by selling it to their subscribers. The MSP determines the spectrum leasing amount and chooses the winning FHs by solving the dynamic programming-based 0-1 knapsack problem. In our proposed framework, we focus on the spectrum pricing strategy and revenue maximization of the MSP. The simulation results show that the proposed scheme provides effective motivation for the MSP to lease the spectrum to FHs, and both the MSP and FHs can benefit from spectrum leasing.

  14. An Auction-Based Spectrum Leasing Mechanism for Mobile Macro-Femtocell Networks of IoT

    PubMed Central

    Chen, Xin; Xing, Lei; Qiu, Tie; Li, Zhuo

    2017-01-01

    The Internet of Things (IoT) is a vision of the upcoming society. It can provide pervasive communication between two or more entities using 4G-LTE (Long Term Evolution) communication technology. In 4G-LTE networks, there are two important problems: helping manage the spectrum demands of IoT devices and achieving much more revenue with the limited resource. This paper proposes a pricing framework to investigate the spectrum leasing in mobile heterogeneous networks with single macrocell and multiple femtocells. We modeled the leasing procedure between the macrocell service provider (MSP) and femtocell holders (FHs) as an auction to motivate the MSP to lease its spectrum resource. All FHs act as the bidders, and the monopolist MSP acts as the auctioneer. In the auction, FHs submit their bids to rent the spectrum resource so that they can make a profit by selling it to their subscribers. The MSP determines the spectrum leasing amount and chooses the winning FHs by solving the dynamic programming-based 0–1 knapsack problem. In our proposed framework, we focus on the spectrum pricing strategy and revenue maximization of the MSP. The simulation results show that the proposed scheme provides effective motivation for the MSP to lease the spectrum to FHs, and both the MSP and FHs can benefit from spectrum leasing. PMID:28212317

  15. Innovations in Defense Acquisition Auctions: Lessons Learned and Alternative Mechanism Designs

    DTIC Science & Technology

    2008-02-21

    Engines, Turbines , and Components $93,321 3 29—Engine Accessories $13,109 3 30—Mechanical Power Transmission Equipment $53,183 5 31— Bearings $9,760 1... balls . In this urn, there are α black balls and β white balls (recall that α + β = 100). An individual player (be it a buyer or seller) infers the...true number of black and white balls in the urn (the true values of α and β) from the information received from its draws (the number of black and

  16. Essays on wholesale auctions in deregulated electricity markets

    NASA Astrophysics Data System (ADS)

    Baltaduonis, Rimvydas

    2007-12-01

    The early experience in the restructured electric power markets raised several issues, including price spikes, inefficiency, security, and the overall relationship of market clearing prices to generation costs. Unsatisfactory outcomes in these markets are thought to have resulted in part from strategic generator behaviors encouraged by inappropriate market design features. In this dissertation, I examine the performance of three auction mechanisms for wholesale power markets - Offer Cost Minimization auction, Payment Cost Minimization auction and Simple-Offer auction - when electricity suppliers act strategically. A Payment Cost Minimization auction has been proposed as an alternative to the traditional Offer Cost Minimization auction with the intention to solve the problem of inflated wholesale electricity prices. Efficiency concerns for this proposal were voiced due to insights predicated on the assumption of true production cost revelation. Using a game theoretic approach and an experimental method, I compare the two auctions, strictly controlling for the level of unilateral market power. A specific feature of these complex-offer auctions is that the sellers submit not only the quantities and the minimum prices that they are willing to sell at, but also the start-up fees, which are designed to reimburse the fixed start-up costs of the generation plants. I find that the complex structure of the offers leaves considerable room for strategic behavior, which consequently leads to anti-competitive and inefficient market outcomes. In the last chapter of my dissertation, I use laboratory experiments to contrast the performance of two complex-offer auctions against the performance of a simple-offer auction, in which the sellers have to recover all their generation costs - fixed and variable - through a uniform market-clearing price. I find that a simple-offer auction significantly reduces consumer prices and lowers price volatility. It mitigates anti-competitive effects

  17. Earthquakes with non--double-couple mechanisms.

    PubMed

    Frohlich, C

    1994-05-06

    Seismological observations confirm that the pattern of seismic waves from some earthquakes cannot be produced by slip along a planar fault surface. More than one physical mechanism is required to explain the observed varieties of these non-double-couple earthquakes. The simplest explanation is that some earthquakes are complex, with stress released on two or more suitably oriented, nonparallel fault surfaces. However, some shallow earthquakes in volcanic and geothermal areas require other explanations. Current research focuses on whether fault complexity explains most observed non-double-couple earthquakes and to what extent ordinary earthquakes have non-double-couple components.

  18. Mechanical response of biopolymer double networks

    NASA Astrophysics Data System (ADS)

    Carroll, Joshua; Das, Moumita

    We investigate a double network model of articular cartilage (AC) and characterize its equilibrium mechanical response. AC has very few cells and the extracellular matrix mainly determines its mechanical response. This matrix can be thought of as a double polymer network made of collagen and aggrecan. The collagen fibers are stiff and resist tension and compression forces, while aggrecans are flexible and control swelling and hydration. We construct a microscopic model made of two interconnected disordered polymer networks, with fiber elasticity chosen to qualitatively mimic the experimental system. We study the collective mechanical response of this double network as a function of the concentration and stiffness of the individual components as well as the strength of the connection between them using rigidity percolation theory. Our results may provide a better understanding of mechanisms underlying the mechanical resilience of AC, and more broadly may also lead to new perspectives on the mechanical response of multicomponent soft materials. This work was partially supported by a Cottrell College Science Award.

  19. Bandwidth auction for SVC streaming in dynamic multi-overlay

    NASA Astrophysics Data System (ADS)

    Xiong, Yanting; Zou, Junni; Xiong, Hongkai

    2010-07-01

    In this paper, we study the optimal bandwidth allocation for scalable video coding (SVC) streaming in multiple overlays. We model the whole bandwidth request and distribution process as a set of decentralized auction games between the competing peers. For the upstream peer, a bandwidth allocation mechanism is introduced to maximize the aggregate revenue. For the downstream peer, a dynamic bidding strategy is proposed. It achieves maximum utility and efficient resource usage by collaborating with a content-aware layer dropping/adding strategy. Also, the convergence of the proposed auction games is theoretically proved. Experimental results show that the auction strategies can adapt to dynamic join of competing peers and video layers.

  20. A novel mechanism for creating double pulsars

    NASA Technical Reports Server (NTRS)

    Sigurdsson, Steinn; Hernquist, Lars

    1992-01-01

    Simulations of encounters between pairs of hard binaries, each containing a neutron star and a main-sequence star, reveal a new formation mechanism for double pulsars in dense cores of globular clusters. In many cases, the two normal stars are disrupted to form a common envelope around the pair of neutron stars, both of which will be spun up to become millisecond pulsars. We predict that a new class of pulsars, double millisecond pulsars, will be discovered in the cores of dense globular clusters. The genesis proceeds through a short-lived double-core common envelope phase, with the envelope ejected in a fast wind. It is possible that the progenitor may also undergo a double X-ray binary phase. Any circular, short-period double pulsar found in the galaxy would necessarily come from disrupted disk clusters, unlike Hulse-Taylor class pulsars or low-mass X-ray binaries which may be ejected from clusters or formed in the galaxy.

  1. A Study of Central Auction Based Wholesale Electricity Markets

    NASA Astrophysics Data System (ADS)

    Ceppi, Sofia; Gatti, Nicola

    The deregulation of electricity markets produced significant economic benefits, reducing prices to customers and opening several opportunities for new actors, e.g., new generators and distributors. A prominent scientific and technological challenge is the automation of such markets. In particular, we focus our attention on wholesale electricity markets based on a central auction. In these markets, generators sell electricity by means of a central auction to a public authority. Instead, the distribution of electricity to customers takes part in retail markets. The main works presented in the literature model wholesale markets as oligopolies, neglecting thus the specific auction mechanism. In this paper, we enrich these models by introducing an auction mechanism shaped on that used in the Italian wholesale electricity market, we solve the winner determination problem, and we preliminarily study the problem of searching for equilibria.

  2. Immune mechanism: a 'double-edged sword'.

    PubMed

    Musa, Mustaffa

    2013-05-01

    Immunology has now developed into an independent discipline in medicine which covers not only germ infection which is related to immunity solely but also covers a lot of non-infectious diseases such as autoimmune disease, allergies, and others. Therefore, "The Immune Mechanism: "A Double-Edged Sword" means that the immune mechanism (consisted of antibody mediated mechanism and T cell mediated mechanism), just like one edge playing the role of giving benefit (immunity) as it destroys the agent of infection, and another one can be detrimental as it will cause tissue/cell damages and then give rise to immune diseases (immunopathology). Now, the prevalence of these immune diseases is on the rise and has become a new challenge to our country towards developed country in 2020. Therefore, we have to make ample preparation (laboratory facilities/services, main power, and research) from now on in order to face the problems and challenges.

  3. Combinatorial Auctions without Money

    DTIC Science & Technology

    2014-05-01

    society itself (and then “reduce” its total happiness ) to ensure truthfulness. CAs without money would avoid this paradox, automatically guarantee...Combinatorial Auctions without Money ∗ Dimitris Fotakis National Technical Univ. of Athens Greece fotakis@cs.ntua.gr Piotr Krysta University of...absence of money , very little can be done to enforce truthfulness. However, in certain applications, money is unavailable, morally unacceptable or might

  4. Cryptanalysis and melioration of secure quantum sealed-bid auction with post-confirmation

    NASA Astrophysics Data System (ADS)

    He, Li-Bao; Huang, Liu-Sheng; Yang, Wei; Xu, Rui; Han, Dian-Qi

    2012-12-01

    We investigate the quantum sealed-bid auction protocol proposed by Zhao et al. (Opt Commun 283:1394, 2010). It uses M groups n-particle GHZ states to represent bids and a post-confirmation mechanism to guarantee the honesty of the quantum sealed-bid auction. However, in our opinion the protocol still does not complete the task of a sealed-bid auction fairly. It is shown that a large group of dishonest bidders can collude to obtain all the other one's secret bids before the opening phase of the auction with a probability polynomially close to one. Moreover, a simple feasible improvement of the protocol is proposed.

  5. The Double Cone: A Mechanical Paradox or a Geometrical Constraint?

    ERIC Educational Resources Information Center

    Gallitto, Aurelio Agliolo; Fiordilino, Emilio

    2011-01-01

    In the framework of the Italian National Plan "Lauree Scientifiche" (PLS) in collaboration with secondary schools, we have investigated the mechanical paradox of the double cone. We have calculated the geometric condition for obtaining an upward movement. Based on this result, we have built a mechanical model with a double cone made of aluminum…

  6. Electronic Reverse Auctions in the Federal Government

    DTIC Science & Technology

    2007-12-01

    feature one buyer (government) and many suppliers (vendors). Electronic reverse auctioning is an internet -based pricing tool that uses traditional...that if it is an internet auction, such as the most popular of all—eBay—then the bids are submitted electronically rather than being shouted. The item... internet -based reverse auction site. 2. Japanese Alper and Boning (2003) presented an interesting variant of the English auction in their research

  7. 40 CFR 73.70 - Auctions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ALLOWANCE SYSTEM Auctions, Direct Sales, and Independent Power Producers Written Guarantee § 73.70 Auctions... years after purchase. *These are unsold advance allowances from the direct sale program for 1993, 1994... Auction Subaccount, including unsold allowances transferred from the preceding year's direct sale, and...

  8. Exploring Online Auction Behaviors and Motivations

    ERIC Educational Resources Information Center

    Jeon, Sua; Crutsinger, Christy; Kim, Haejung

    2008-01-01

    The availability and convenience of the Internet, combined with the variety of products available at any given time, have contributed to the success of online auctions.This exploratory study examined online auction behaviors among college students in an attempt to identify underlying dimensions of auction motivations. Questionnaires completed by…

  9. Internet Auction Sellers: Does Size Really Matter?

    ERIC Educational Resources Information Center

    Halstead, Diane; Becherer, Richard C.

    2003-01-01

    Examines the Internet auction phenomenon as it relates to the marketing mix of online auction sellers. The data indicate that, while there is great diversity among businesses that utilize online auctions, distinct cost leadership and differentiation marketing strategies are both evident. These two approaches are further distinguished in terms of…

  10. China's Land Market Auctions: Evidence of Corruption?

    PubMed

    Cai, Hongbin; Henderson, J Vernon; Zhang, Qinghua

    2013-01-01

    This paper studies the urban land market in China in 2003-2007. In China, all urban land is owned by the state. Leasehold use rights for land for (re)development are sold by city governments and are a key source of city revenue. Leasehold sales are viewed as a major venue for corruption, prompting a number of reforms over the years. Reforms now require all leasehold rights be sold at public auction. There are two main types of auction: regular English auction and an unusual type which we call a "two stage auction". The latter type of auction seems more subject to corruption, and to side deals between potential bidders and the auctioneer. Absent corruption, theory suggests that two stage auctions would most likely maximize sales revenue for properties which are likely to have relatively few bidders, or are "cold", which would suggest negative selection on property unobservables into such auctions. However, if such auctions are more corruptible, that could involve positive selection as city officials divert hotter properties to a more corruptible auction form. The paper finds that, overall, sales prices are lower for two stage auctions, and there is strong evidence of positive selection. The price difference is explained primarily by the fact that two stage auctions typically have just one bidder, or no competition despite the vibrant land market in Chinese cities.

  11. 7 CFR 1955.148 - Auction sales.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 14 2010-01-01 2009-01-01 true Auction sales. 1955.148 Section 1955.148 Agriculture... REGULATIONS (CONTINUED) PROPERTY MANAGEMENT Disposal of Inventory Property General § 1955.148 Auction sales. This section provides guidance on the sale of all inventory property by auction, except FSA...

  12. 7 CFR 46.25 - Auction sales.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Auction sales. 46.25 Section 46.25 Agriculture... THAN RULES OF PRACTICE) UNDER THE PERISHABLE AGRICULTURAL COMMODITIES ACT, 1930 Auction Sales § 46.25 Auction sales. Commission merchants, dealers and brokers who offer produce for sale through...

  13. Molecular mechanism of double Holliday junction dissolution

    PubMed Central

    2014-01-01

    Processing of homologous recombination intermediates is tightly coordinated to ensure that chromosomal integrity is maintained and tumorigenesis avoided. Decatenation of double Holliday junctions, for example, is catalysed by two enzymes that work in tight coordination and belong to the same ‘dissolvasome’ complex. Within the dissolvasome, the RecQ-like BLM helicase provides the translocase function for Holliday junction migration, while the topoisomerase III alpha-RMI1 subcomplex works as a proficient DNA decatenase, together resulting in double-Holliday-junction unlinking. Here, we review the available architectural and biochemical knowledge on the dissolvasome machinery, with a focus on the structural interplay between its components. PMID:25061510

  14. Statistical Properties of Online Auctions

    NASA Astrophysics Data System (ADS)

    Namazi, Alireza; Schadschneider, Andreas

    We characterize the statistical properties of a large number of online auctions run on eBay. Both stationary and dynamic properties, like distributions of prices, number of bids etc., as well as relations between these quantities are studied. The analysis of the data reveals surprisingly simple distributions and relations, typically of power-law form. Based on these findings we introduce a simple method to identify suspicious auctions that could be influenced by a form of fraud known as shill bidding. Furthermore the influence of bidding strategies is discussed. The results indicate that the observed behavior is related to a mixture of agents using a variety of strategies.

  15. Mechanical seal having a double-tier mating ring

    SciTech Connect

    Khonsari, Michael M.; Somanchi, Anoop K.

    2005-09-13

    An apparatus and method to enhance the overall performance of mechanical seals in one of the following ways: by reducing seal face wear, by reducing the contact surface temperature, or by increasing the life span of mechanical seals. The apparatus is a mechanical seal (e.g., single mechanical seals, double mechanical seals, tandem mechanical seals, bellows, pusher mechanical seals, and all types of rotating and reciprocating machines) comprising a rotating ring and a double-tier mating ring. In a preferred embodiment, the double-tier mating ring comprises a first and a second stationary ring that together form an agitation-inducing, guided flow channel to allow for the removal of heat generated at the seal face of the mating ring by channeling a coolant entering the mating ring to a position adjacent to and in close proximity with the interior surface area of the seal face of the mating ring.

  16. Mechanically tough, elastic and stable rope-like double nanohelices.

    PubMed

    Dai, L; Huang, X J; Dong, L X; Zhang, Q; Zhang, L

    2014-08-21

    Double helix nanostructures have been the object of intense theoretical and experimental investigations in recent years due to their various types of available materials and unique morphology. Among these structures, rope-like double nanohelices of two strands in contact along a line can be obtained using any one-dimensional nanostructure. In this work, we establish a novel theory for quantitatively exploring the statics and dynamics of rope-like double nanohelices by employing the concept of the extensible Cosserat curve. The rope-like double nanohelices are tough, relatively elastic, and mechanically stable, which agrees well with the experiments. The characteristics of the interaction between the two strands, the tensile modulus and the torque are precisely described and explained across the entire stretching region. The proposed model offers in depth quantitative insight into the mechanics of double helix nanostructures, and supplies a reliable reference for further experimental research.

  17. Multiparty quantum sealed-bid auction using single photons as message carrier

    NASA Astrophysics Data System (ADS)

    Liu, Wen-Jie; Wang, Hai-Bin; Yuan, Gong-Lin; Xu, Yong; Chen, Zhen-Yu; An, Xing-Xing; Ji, Fu-Gao; Gnitou, Gnim Tchalim

    2016-02-01

    In this study, a novel multiparty quantum sealed-bid auction protocol using the single photons as the message carrier of bids is proposed, followed by an example of three-party auction. Compared with those protocols based on the entangled states (GHZ state, EPR pairs, etc.), the present protocol is more economic and feasible within present technology. In order to guarantee the security and the fairness of the auction, the decoy photon checking technique and an improved post-confirmation mechanism with EPR pairs are introduced, respectively.

  18. Auctions with Dynamic Populations: Efficiency and Revenue Maximization

    NASA Astrophysics Data System (ADS)

    Said, Maher

    We study a stochastic sequential allocation problem with a dynamic population of privately-informed buyers. We characterize the set of efficient allocation rules and show that a dynamic VCG mechanism is both efficient and periodic ex post incentive compatible; we also show that the revenue-maximizing direct mechanism is a pivot mechanism with a reserve price. We then consider sequential ascending auctions in this setting, both with and without a reserve price. We construct equilibrium bidding strategies in this indirect mechanism where bidders reveal their private information in every period, yielding the same outcomes as the direct mechanisms. Thus, the sequential ascending auction is a natural institution for achieving either efficient or optimal outcomes.

  19. Auctions for coastal energy resources

    NASA Astrophysics Data System (ADS)

    Griffin, Robert M.

    It is becoming increasingly common to allocate public resources to the private sector for the purpose of developing these resources. One of the earliest uses of auctions in the U.S. for allocating rights to public resources was in the offshore oil and gas industry. The U.S. Federal government, through the Department of Interior (DOI), has used auctions to allocate development rights to offshore oil and gas resources to the private sector since the 1950's. Since then many things have changed. Oil and gas markets have gone through boom and bust cycles, giant technological advances in extraction and assessment have taken place, and alternative energy based in the coastal zone is now in demand in markets as well. There has been an enormous amount of research into the drivers of bidder behavior in auctions and optimal auction design in the last 60 years as well. Throughout all of this, the DOI has continued to use basically the same exact auction design to allocate oil and gas leases. The U.S. offshore oil and gas resources sold by the Department of Interior have accounted for more than $65 billion in revenue since the program started. These offshore resources are an important source of government revenue and national wealth. Additionally, the expansion of the energy sector offshore has enormous potential for electricity generation in the U.S., estimated by the National Renewable Energy Laboratory as approaching 54 gigawatts by 2030 (U.S. Department of Energy, 2008). Taken together, the DOI controls access to a large part of the future of energy in the U.S. The research herein assesses the auction formats used to allocate both fossil fuels and renewable resources on the Outer Continental Shelf (OCS). The first manuscript looks at the current method used by the DOI to allocate oil and gas leases on the OCS, and is primarily interested in how bidders behave in this environment. Using latent class estimation techniques to separate distinct bidding behavior in a laboratory

  20. A Theory of Auctions and Competitive Bidding.

    DTIC Science & Technology

    1981-12-01

    seventh century A.D.2/ In the United States in the 1980’ s , auctions account for an enormous volume of economic activity. Every week, the U.S. Treasury...auction - S games must coincide. Initially, this strategic equivalence of the two auction forms may seem puzzling. It might appear that after a bidder...to the bidder depends only on the rules of the auction and the strategies of the others, and not on his private valuation of the * object. ’ S Figure

  1. Toughening Mechanism of Double Network Hydrogels

    NASA Astrophysics Data System (ADS)

    Gong, Jian Ping

    2010-03-01

    The fundamental toughening mechanism of DN gels [1] is of great interest to researchers. Extensive experimental and theoretical studies have been performed to explain this mechanism [2-7]. Yielding and necking deformation [2] that was observed through tensile tests and rate-independent hysteresis [3] observed through cyclic loading tests have indicated that DN gels can accumulate internal damage before the suffering macroscopic fracture; after damage accumulation, the DN gels become much softer. We assume that on the microscopic level, yielding is caused by the partial breakage and fragmentation of the brittle first network and interconnection among the fragments by the polymer chains of second network [2]. Brown [4] and Tanaka [5] have proposed similar models that can qualitatively explain the anomalously high fracture energy, assuming that the DN gel is locally damaged (yielded) around the crack tip and that the energy dissipated for damage accumulation enhances the effective fracture energy. Using AFM measurements [6] and 3D color laser microscope[7], we successfully detected the existence of softened regions, of several hundreds μm in thickness, at the crack tip just below the fracture surfaces, which supports the assumption of localized damage accumulation. A linear relationship between the thickness of the softened yielding zone and the fracture energy of the gel was observed, which is in agreement with the local yielding zone explanation. [4pt] [1] Gong, J. P.; Katsuyama, Y.; Kurokawa, T.; Osada, Y. Adv. Mater. 2003, 15, 1155. [0pt] [2] Na Y.H., Tanaka Y., Kawauchi Y., Furukawa H., Sumiyoshi T., Gong J. P., Osada Y., Macromolecules 2006, 39(14), 4641. [0pt] [3] Webber, R. E.; Creton, C.; Brown, H. R.; Gong, J. P. Macromolecules 2007, 40, 2919. [0pt] [4] Brown, H. R. Macromolecules 2007, 40, 3815. [0pt] [5] Tanaka, Y. Euro Phys. Letter. 2007, 78, 56005. [0pt] [6] Tanaka Y.; Kawauchi Y.; Kurokawa T.; Furukawa H.; Okajima T.; Gong J. P. Macrom. Rapid Comm

  2. 7 CFR 29.36 - Auction market.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Auction market. 29.36 Section 29.36 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.36 Auction market. A place to which tobacco is delivered by...

  3. 7 CFR 29.36 - Auction market.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Auction market. 29.36 Section 29.36 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.36 Auction market. A place to which tobacco is delivered by...

  4. 7 CFR 29.36 - Auction market.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Auction market. 29.36 Section 29.36 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.36 Auction market. A place to which tobacco is delivered by...

  5. 7 CFR 29.36 - Auction market.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Auction market. 29.36 Section 29.36 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.36 Auction market. A place to which tobacco is delivered by...

  6. 7 CFR 29.36 - Auction market.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Auction market. 29.36 Section 29.36 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.36 Auction market. A place to which tobacco is delivered by...

  7. 29 CFR 780.617 - Adjunct livestock auction operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Adjunct livestock auction operations. 780.617 Section 780... Employment in Agriculture and Livestock Auction Operations Under the Section 13(b)(13) Exemption Requirements for Exemption § 780.617 Adjunct livestock auction operations. The livestock auction...

  8. Collusion in Auctions for Emission Permits: An Experimental Analysis

    ERIC Educational Resources Information Center

    Burtraw, Dallas; Goeree, Jacob; Holt, Charles A.; Myers, Erica; Palmer, Karen; Shobe, William

    2009-01-01

    Environmental markets have several institutional features that provide a new context for the use of auctions and that have not been studied previously. This paper reports on laboratory experiments testing three auction forms--uniform and discriminatory price sealed-bid auctions and an ascending clock auction. We test the ability of subjects to…

  9. 77 FR 57085 - Mobility Fund Phase I Auction; Release of Files with Recalculated Road Miles for Auction 901...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-17

    ... COMMISSION Mobility Fund Phase I Auction; Release of Files with Recalculated Road Miles for Auction 901; Mock... updated data files of census blocks eligible for the Mobility Fund Phase I support to be offered in Auction 901, which is to be held on September 27, 2012, and the change of the mock auction date...

  10. Auction-based resource allocation game under a hierarchical structure

    NASA Astrophysics Data System (ADS)

    Cui, Yingying; Zou, Suli; Ma, Zhongjing

    2016-01-01

    This paper studies a class of auction-based resource allocation games under a hierarchical structure, such that each supplier is assigned a certain amount of resource from a single provider and allocates it to its buyers with auction mechanisms. To implement the efficient allocations for the underlying hierarchical system, we first design an auction mechanism, for each local system composed of a supplier and its buyers, which inherits the advantages of the progressive second price mechanism. By employing a dynamic algorithm, each local system converges to its own efficient Nash equilibrium, at which the efficient resource allocation is achieved and the bidding prices of all the buyers in this local system are identical with each other. After the local systems reach their own equilibria respectively, the resources assigned to suppliers are readjusted via a dynamic hierarchical algorithm with respect to the bidding prices associated with the implemented equilibria of local systems. By applying the proposed hierarchical process, the formulated hierarchical system can converge to the efficient allocation under certain mild conditions. The developed results in this work are demonstrated with simulations.

  11. Sequential Auctions in Uncertain Information Settings

    NASA Astrophysics Data System (ADS)

    Fatima, Shaheen; Wooldridge, Michael; Jennings, Nicholas R.

    This paper analyzes sequential auctions for private value objects using second-price sealed-bid rules. Now, the equilibrium bids for such auctions depend on the information uncertainty of the bidders. Specifically, there are three key auction parameters that the bidders could be uncertain about: the valuations of the objects for sale, the number of objects for sale, and the number of participating bidders. We analyse the bidding behaviour for each of these three sources of uncertainty. For each setting, we first find the equilibrium bidding strategies for the individual auctions that comprise a series. Then we analyze the effect of these uncertainties on the computational and economic properties of the equilibrium solution. The former analysis is essential if we want to use software agents to bid on our behalf. The latter is essential because both the auctioneer and the bidders want to know how these uncertainties affect their profits. Thus we compare the outcomes for these settings from the perspective of the bidders (i.e., in terms of their profits), from the perspective of the auctioneer (i.e., in terms of his revenue), and from a global perspective (i.e., in terms of auction efficiency).

  12. Electrical power generation by mechanically modulating electrical double layers.

    PubMed

    Moon, Jong Kyun; Jeong, Jaeki; Lee, Dongyun; Pak, Hyuk Kyu

    2013-01-01

    Since Michael Faraday and Joseph Henry made their great discovery of electromagnetic induction, there have been continuous developments in electrical power generation. Most people today get electricity from thermal, hydroelectric, or nuclear power generation systems, which use this electromagnetic induction phenomenon. Here we propose a new method for electrical power generation, without using electromagnetic induction, by mechanically modulating the electrical double layers at the interfacial areas of a water bridge between two conducting plates. We find that when the height of the water bridge is mechanically modulated, the electrical double layer capacitors formed on the two interfacial areas are continuously charged and discharged at different phases from each other, thus generating an AC electric current across the plates. We use a resistor-capacitor circuit model to explain the results of this experiment. This observation could be useful for constructing a micro-fluidic power generation system in the near future.

  13. Quantum auctions: Facts and myths

    NASA Astrophysics Data System (ADS)

    Piotrowski, Edward W.; Sładkowski, Jan

    2008-06-01

    Quantum game theory, whatever opinions may be held due to its abstract physical formalism, have already found various applications even outside the orthodox physics domain. In this paper we introduce the concept of a quantum auction, its advantages and drawbacks. Then we describe the models that have already been put forward. A general model involves Wigner formalism and infinite dimensional Hilbert spaces - we envisage that the implementation might not be an easy task. But a restricted model advocated by the Hewlett-Packard group (Hogg et al.) seems to be much easier to implement. We focus on problems related to combinatorial auctions and technical assumptions that are made. Powerful quantum algorithms for finding solutions would extend the range of possible applications. Quantum strategies, being qubits, can be teleported but are immune from cloning - therefore extreme privacy of the agent’s activity could in principle be guaranteed. Then we point out some key problems that have to be solved before commercial use would be possible. With present technology, optical networks, single photon sources and detectors seems to be sufficient for an experimental realization in the near future.

  14. Auction-based distributed efficient economic operations of microgrid systems

    NASA Astrophysics Data System (ADS)

    Zou, Suli; Ma, Zhongjing; Liu, Xiangdong

    2014-12-01

    This paper studies the economic operations of the microgrid in a distributed way such that the operational schedule of each of the units, like generators, load units, storage units, etc., in a microgrid system, is implemented by autonomous agents. We apply and generalise the progressive second price (PSP) auction mechanism which was proposed by Lazar and Semret to efficiently allocate the divisible network resources. Considering the economic operation for the microgrid systems, the generators play as sellers to supply energy and the load units play as the buyers to consume energy, while a storage unit, like battery, super capacitor, etc., may transit between buyer and seller, such that it is a buyer when it charges and becomes a seller when it discharges. Furthermore in a connected mode, each individual unit competes against not only the other individual units in the microgrid but also the exogenous main grid possessing fixed electricity price and infinite trade capacity; that is to say, the auctioneer assigns the electricity among all individual units and the main grid with respect to the submitted bid strategies of all individual units in the microgrid in an economic way. Due to these distinct characteristics, the underlying auction games are distinct from those studied in the literature. We show that under mild conditions, the efficient economic operation strategy is a Nash equilibrium (NE) for the PSP auction games, and propose a distributed algorithm under which the system can converge to an NE. We also show that the performance of worst NE can be bounded with respect to the system parameters, say the energy trading price with the main grid, and based upon that, the implemented NE is unique and efficient under some conditions.

  15. Waveguide formation mechanism generated by double doping in ferroelectric crystals

    NASA Astrophysics Data System (ADS)

    Atuchin, V. V.; Ziling, C. C.; Savatinova, I.; Armenise, M. N.; Passaro, V. M. N.

    1995-12-01

    Physical mechanisms causing the refractive index increase Δn in uniaxial oxidized ferroelectric crystals subjected to double doping are discussed. The analysis shows that the index changes of the two different dopants, ΔnA and ΔnB, are additive only if the corresponding changes of the spontaneous polarization are small. Ti indiffusion and proton exchange (TIPE) waveguides in LiNbO3 are considered as an example of the case when this condition is not fulfilled. The hydrogen-lithium substitution in such waveguides leads to a strong reduction of the spontaneous polarization of the virgin crystals and the final index change Δn is not a sum of ΔnA and ΔnB. A physical model is developed to explain light waveguiding in double-doped ferroelectric structures. Experimental data obtained for TIPE waveguides confirm the model.

  16. Sold!: Auction Methods for Multirobot Coordination

    DTIC Science & Technology

    2002-10-01

    758 IEEE TRANSACTIONS ON ROBOTICS AND AUTOMATION, VOL. 18, NO. 5, OCTOBER 2002 Sold!: Auction Methods for Multirobot Coordination Brian P. Gerkey and...Auctions have been 760 IEEE TRANSACTIONS ON ROBOTICS AND AUTOMATION, VOL. 18, NO. 5, OCTOBER 2002 demonstrated in the control of simulated robots...different robots execute the same task using different resources. 762 IEEE TRANSACTIONS ON ROBOTICS AND AUTOMATION, VOL. 18, NO. 5, OCTOBER 2002 is

  17. 40 CFR 73.73 - Delegation of auctions and sales and termination of auctions and sales.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) SULFUR DIOXIDE ALLOWANCE SYSTEM Auctions, Direct Sales, and Independent Power Producers Written Guarantee § 73.73 Delegation of auctions and sales and termination of... consecutive calendar years, fewer than 20 percent of the allowances available in the subaccount for...

  18. 76 FR 81932 - Auction of FM Broadcast Construction Permits; Revised Construction Permit Number in Auction 93

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-29

    ... FURTHER INFORMATION CONTACT: Linda Sanderson, Wireless Telecommunications Bureau, Auctions and Spectrum...://wireless.fcc.gov/auctions/93/ , or by using the search function for AU Docket No. 11-146 on the Commission... Wireless Telecommunications and Media Bureaus announce a change to the construction permit number for...

  19. Double-exchange mechanism in rare-earth compounds

    SciTech Connect

    Gulacsi, M.

    2015-03-15

    We show that double-exchange mechanism is responsible for ferromagnetism in low dimensional rare-earth compounds. We use the bosonized version of the one-dimensional Anderson lattice model in Toulouse limit to characterize the properties of the emerging ferromagnetic phase. We give a comprehensive description of the ferromagnetic ordering of the correlated electrons which appears at intermediate couplings and doping. The obtained ferromagnetic phase transitions have been identified to be an order–disorder transition of the quantum random transverse-field Ising type.

  20. Design Implications of Real-Time Feedback in Continuous Combinatorial Auctions: An Experimental Investigation

    ERIC Educational Resources Information Center

    Sanyal, Pallab

    2009-01-01

    Information Technology (IT) has spawned the growth of novel and innovative market mechanisms (such as online auctions) and associated businesses (such as eBay and Priceline) that were not feasible without the capabilities and reach of these modern information technologies. Previous studies on designing trading mechanisms for online markets…

  1. A Bayesian formulation for auction-based task allocation in heterogeneous multi-agent teams

    NASA Astrophysics Data System (ADS)

    Pippin, Charles E.; Christensen, Henrik

    2011-06-01

    In distributed, heterogeneous, multi-agent teams, agents may have different capabilities and types of sensors. Agents in dynamic environments will need to cooperate in real-time to perform tasks with minimal costs. Some example scenarios include dynamic allocation of UAV and UGV robot teams to possible hurricane survivor locations, search and rescue and target detection. Auction based algorithms scale well because agents generally only need to communicate bid information. In addition, the agents are able to perform their computations in parallel and can operate on local information. Furthermore, it is easy to integrate humans and other vehicle types and sensor combinations into an auction framework. However, standard auction mechanisms do not explicitly consider sensors with varying reliability. The agents sensor qualities should be explicitly accounted. Consider a scenario with multiple agents, each carrying a single sensor. The tasks in this case are to simply visit a location and detect a target. The sensors are of varying quality, with some having a higher probability of target detection. The agents themselves may have different capabilities, as well. The agents use knowledge of their environment to submit cost-based bids for performing each task and an auction is used to perform the task allocation. This paper discusses techniques for including a Bayesian formulation of target detection likelihood into this auction based framework for performing task allocation across multi-agent heterogeneous teams. Analysis and results of experiments with multiple air systems performing distributed target detection are also included.

  2. Auctionable fixed transmission rights for congestion management

    NASA Astrophysics Data System (ADS)

    Alomoush, Muwaffaq Irsheid

    the transaction by the ISO, take a decision to expand the existing system, or retain the original structure of the system. Also, the thesis investigates the impact of wheeling transactions on congestion management, where we present a generalized mathematical model for the Fixed Transmission Right (FTR) auction. The auction guarantees FTR availability to all participants on a non-discriminatory basis, in which system users are permitted to buy, sell and trade FTRs through an auction. When FTRs are utilized with LMPs, they increase the efficient use of the transmission system and let a transmission customer gain advantageous features such as acquiring a mechanism to offset the extra cost due to congestion charges, providing financial and operational certainty and making system users pay for the actual use of the congested paths. The thesis also highlighted FTR trading in secondary markets to self-arrange access across different paths, create long-term transmission rights and provide more commercial certainty.

  3. Electrical Power Generation by Mechanically Modulating Electrical Double Layers

    NASA Astrophysics Data System (ADS)

    Pak, Hyuk Kyu; Moon, Jong Kyun

    2014-11-01

    Since Michael Faraday and Joseph Henry made their great discovery of electromagnetic induction, there have been continuous developments in electrical power generation. Most people today get electricity from thermal, hydroelectric, or nuclear power generation systems, which use this electromagnetic induction phenomenon. Here we propose a new method for electrical power generation, without using electromagnetic induction, by mechanically modulating the electrical double layers at the interfacial areas of a water bridge between two conducting plates. We find that when the height of the water bridge is mechanically modulated, the electrical double layer capacitors formed on the two interfacial areas are continuously charged and discharged at different phases from each other, thus generating an AC electric current across the plates. We use a resistor-capacitor circuit model to explain the results of this experiment. This observation could be useful for constructing a micro-fluidic power generation system and for understanding the interfacial charge distribution in solid-liquid interfaces in the near future. This work was supported by Center for Soft and Living Matter through IBS prgram in Korea.

  4. Prior-Free Multi-Unit Auctions with Ordered Bidders

    DTIC Science & Technology

    2014-05-01

    case, the Bayesian optimal auction awards items to the (at most k) bidders with the highest positive virtual valuations. The payment of a winning...Prior-Free Multi-Unit Auctions with Ordered Bidders∗ Sayan Bhattacharya† Elias Koutsoupias‡ Janardhan Kulkarni§ Stefano Leonardi¶ Tim Roughgarden...Xiaoming Xu∗∗ Abstract Prior-free auctions are robust auctions that assume no distribution over bidders’ valuations and provide worst-case (input-by

  5. Bidding Agents That Perpetrate Auction Fraud

    NASA Astrophysics Data System (ADS)

    Trevathan, Jarrod; McCabe, Alan; Read, Wayne

    This paper presents a software bidding agent that inserts fake bids on the seller's behalf to inflate an auction's price. This behaviour is referred to as shill bidding. Shill bidding is strictly prohibited by online auctioneers, as it defrauds unsuspecting buyers by forcing them to pay more for the item. The malicious bidding agent was constructed to aid in developing shill detection techniques. We have previously documented a simple shill bidding agent that incrementally increases the auction price until it reaches the desired profit target, or it becomes too risky to continue bidding. This paper presents an adaptive shill bidding agent which when used over a series of auctions with substitutable items, can revise its strategy based on bidding behaviour in past auctions. The adaptive agent applies a novel prediction technique referred to as the Extremum Consistency (EC) algorithm, to determine the optimal price to aspire for. The EC algorithm has successfully been used in handwritten signature verification for determining the maximum and minimum values in an input stream. The agent's ability to inflate the price has been tested in a simulated marketplace and experimental results are presented.

  6. Control mechanism of double-rotator-structure ternary optical computer

    NASA Astrophysics Data System (ADS)

    Kai, SONG; Liping, YAN

    2017-03-01

    Double-rotator-structure ternary optical processor (DRSTOP) has two characteristics, namely, giant data-bits parallel computing and reconfigurable processor, which can handle thousands of data bits in parallel, and can run much faster than computers and other optical computer systems so far. In order to put DRSTOP into practical application, this paper established a series of methods, namely, task classification method, data-bits allocation method, control information generation method, control information formatting and sending method, and decoded results obtaining method and so on. These methods form the control mechanism of DRSTOP. This control mechanism makes DRSTOP become an automated computing platform. Compared with the traditional calculation tools, DRSTOP computing platform can ease the contradiction between high energy consumption and big data computing due to greatly reducing the cost of communications and I/O. Finally, the paper designed a set of experiments for DRSTOP control mechanism to verify its feasibility and correctness. Experimental results showed that the control mechanism is correct, feasible and efficient.

  7. A mechanism that triggers double arcing during plasma arc cutting

    NASA Astrophysics Data System (ADS)

    Nemchinsky, Valerian

    2009-10-01

    Double arcing (DA) is a phenomenon when a transferred arc, flowing inside an electrically insulated nozzle, breaks into two separate arcs: one that connects the cathode and the nozzle and another that connects the nozzle and a work-piece. It is a commonly accepted opinion that the reason for DA is high voltage drop in the plasma inside the nozzle. However, the specific mechanism that triggers the DA development is not clear. In this paper, we propose such a mechanism. Dielectric films deposited inside the nozzle's orifice play the key role in this mechanism. These films are charged by ion current from plasma. A strong electric field is created inside the film and at the boundary of the film and clean metal of the nozzle. This gives rise to a thermo-field electron emission from the clean metal that borders the film. Emitted electrons are accelerated at the voltage drop between the nozzle and plasma. These electrons produce extra ions, which in turn move back to the film and additionally charge it. This sequence of events leads to explosive instability if the voltage drop inside the nozzle is high enough. Experiments to check the proposed mechanism are suggested.

  8. Shock interaction mechanisms on a double wedge at Mach 7

    NASA Astrophysics Data System (ADS)

    Durna, Ahmet Selim; El Hajj Ali Barada, Mohamad; Celik, Bayram

    2016-09-01

    Present computational study investigates formation and interaction mechanisms of shocks and boundary layer for low enthalpy Mach 7 flows of nitrogen over double wedges, which have fixed fore and various aft angles of 30° and 45°-60°, respectively. We use a density based finite-volume Navier-Stokes solver to simulate low enthalpy Mach 7 flows of nitrogen over double wedges. The solver is first and second order accurate in time and space, respectively. The meshes used in simulations of two-dimensional laminar flows consist of multiple blocks of structured mesh. Depending on the intensity, impingement angle, and impingement location of transmitted shock wave, the resulting adverse pressure gradient related disturbances on the wedge surface can trigger complex flow physics both in subsonic and supersonic regions. We observe a strong interaction between the deformation of the boundary layer and the bow shock as well as the transmitted shock for high aft angles. Comparison of the obtained results in terms of general flow physics shows that there exists an aft angle threshold value for such interaction which is in the range of 45°-50°.

  9. Reciprocity in Online Markets: Empirical Studies of Auction and Barter Markets

    ERIC Educational Resources Information Center

    Ye, Shun

    2013-01-01

    My dissertation seeks to understand how reciprocity affects transaction outcomes and mechanism design in online markets. The first essay examines negative reciprocity illustrated as feedback-revoking behavior in the eBay auction market, focusing on its impact and implications for reputation system design. I utilize the biggest policy change of…

  10. China’s Land Market Auctions: Evidence of Corruption?

    PubMed Central

    Cai, Hongbin; Henderson, J. Vernon; Zhang, Qinghua

    2013-01-01

    This paper studies the urban land market in China in 2003—2007. In China, all urban land is owned by the state. Leasehold use rights for land for (re)development are sold by city governments and are a key source of city revenue. Leasehold sales are viewed as a major venue for corruption, prompting a number of reforms over the years. Reforms now require all leasehold rights be sold at public auction. There are two main types of auction: regular English auction and an unusual type which we call a “two stage auction”. The latter type of auction seems more subject to corruption, and to side deals between potential bidders and the auctioneer. Absent corruption, theory suggests that two stage auctions would most likely maximize sales revenue for properties which are likely to have relatively few bidders, or are “cold”, which would suggest negative selection on property unobservables into such auctions. However, if such auctions are more corruptible, that could involve positive selection as city officials divert hotter properties to a more corruptible auction form. The paper finds that, overall, sales prices are lower for two stage auctions, and there is strong evidence of positive selection. The price difference is explained primarily by the fact that two stage auctions typically have just one bidder, or no competition despite the vibrant land market in Chinese cities. PMID:25506125

  11. 47 CFR 1.2208 - Public notice of auction completion and auction results.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... PROCEDURE Grants by Random Selection Competitive Bidding Proceedings Broadcast Television Spectrum Reverse... broadcast television spectrum incentive auction conducted under section 6403 of the Spectrum Act, public... indicate that the reassignments of television channels and reallocations of broadcast television...

  12. Analysis of femtosecond quantum control mechanisms with colored double pulses

    SciTech Connect

    Vogt, Gerhard; Nuernberger, Patrick; Selle, Reimer; Dimler, Frank; Brixner, Tobias; Gerber, Gustav

    2006-09-15

    Fitness landscapes based on a limited number of laser pulse shape parameters can elucidate reaction pathways and can help to find the underlying control mechanism of optimal pulses determined by adaptive femtosecond quantum control. In a first experiment, we employ colored double pulses and systematically scan both the temporal subpulse separation and the relative amplitude of the two subpulses to acquire fitness landscapes. Comparison with results obtained from a closed-loop experiment demonstrates the capability of fitness landscapes for the revelation of possible control mechanisms. In a second experiment, using transient absorption spectroscopy, we investigate and compare the dependence of the excitation efficiency of the solvated dye molecule 5,5{sup '}-dichloro-11-diphenylamino-3,3{sup '}-diethyl-10,12-ethylene thiatricarbocyanine perchlorate (IR140) on selected pulse shapes in two parametrizations. The results show that very different pulse profiles can be equivalently adequate to maximize a given control objective. Fitness landscapes thus provide valuable information about different pathways along which a molecular system can be controlled with shaped laser pulses.

  13. Experiments in Deaccessioning: Archives and Online Auctions.

    ERIC Educational Resources Information Center

    Doylen, Michael

    2001-01-01

    Discussion of the need for archives to remove duplicate or unneeded materials from their collection focuses on the legal and ethical issues raised for archives by the use of online auction venues in deaccessioning unwanted materials, based on experiences at the University of Wisconsin. (Author/LRW)

  14. 19 CFR 127.34 - Auctioneer's commissions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Auctioneer's commissions. 127.34 Section 127.34 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY GENERAL ORDER, UNCLAIMED, AND ABANDONED MERCHANDISE Proceeds of Sale § 127.34...

  15. Books at Auction: The Art of Deaccessioning.

    ERIC Educational Resources Information Center

    Model, Peter

    1981-01-01

    Lack of space and budget cuts force many libraries to weed out books and to be selective in accepting collection bequests. The approach for deciding which books to weed out and whether to dispose of these books through dealers or auctions are decisions private clubs and many libraries must make. (RBF)

  16. 43 CFR 2546.4 - Public auctions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Public auctions. 2546.4 Section 2546.4 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) COLOR-OF-TITLE AND OMITTED LANDS Snake...

  17. 43 CFR 2546.4 - Public auctions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Public auctions. 2546.4 Section 2546.4 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) COLOR-OF-TITLE AND OMITTED LANDS Snake...

  18. 43 CFR 2546.4 - Public auctions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Public auctions. 2546.4 Section 2546.4 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) COLOR-OF-TITLE AND OMITTED LANDS Snake...

  19. 43 CFR 2546.4 - Public auctions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Public auctions. 2546.4 Section 2546.4 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) COLOR-OF-TITLE AND OMITTED LANDS Snake...

  20. Double Higgs mechanisms, supermassive stable particles and the vacuum energy

    NASA Astrophysics Data System (ADS)

    Santillán, Osvaldo P.; Gabbanelli, Luciano

    2016-07-01

    In the present work, a hidden scenario which cast a long-lived superheavy particle A0 and simultaneously an extremely light particle a with mass ma ˜ 10-32-10-33 eV is presented. The potential energy V (a) of the particle a models the vacuum energy density of the universe ρc ≃ 10-47GeV4. On the other hand, the A0 particle may act as superheavy dark matter at present times and the products of its decay may be observed in high energy cosmic ray events. The hidden sector proposed here include light fermions with masses near the neutrino mass mν ˜ 10-2 eV and superheavy ones with masses of the order of the GUT scale, interacting through a hidden SU(2)L interaction which also affects the ordinary sector. The construction of such combined scenario is nontrivial since the presence of light particles may spoil the stability of the heavy particle A0. However, double Higgs mechanisms may be helpful for overcoming this problem. In this context, the stability of the superheavy particle A0 is ensured due to chiral symmetry arguments elaborated in the text.

  1. Market power in auction and efficiency in emission permits allocation.

    PubMed

    Jiang, Min Xing; Yang, Dong Xiao; Chen, Zi Yue; Nie, Pu Yan

    2016-12-01

    This paper analyzes how to achieve the cost-effectiveness by initial allocation of CO2 emission permits when a single dominant firm in production market has market power in auction, and compare two prevalent allocation patterns, mixed allocation and single auction. We show how the firm with market power may manipulate the auction price, thereby this leads to fail to achieve cost-effective solution by auction unless the total permits for allocation equal to the effective emissions cap. Provided that the market power firm receives strictly positive free permits, the effective emissions cap of mixed allocation is larger than that of single auction. The production market share of dominant firm is increasing with the free permits it holds. Finally, we examine the compliance costs and welfare of mixed allocation and single auction, the result show that the former is preferred to the later when policy makers consider economic welfare without welfare cost due to CO2 emissions.

  2. Auction design and the market for sulfur dioxide emissions

    SciTech Connect

    Joskow, P.L.; Schmalensee, R.; Bailey, E.M.

    1997-12-31

    Title IV of the Clean Air Act Amendments of 1990 created a market for electric utility emissions of sulfur dioxide (SO{sub 2}). Recent papers have argued that flaws in the design of the auctions that are part of this market have adversely affected its performance. These papers incorrectly assume that trade can only occur at auctions, however. Our empirical analysis of the SO{sub 2} emissions market shows that the auctions have become a small part of a relatively efficient market and that the auction design problems that have attracted the most attention have had no effect on actual market prices.

  3. Auctions vs negotiations: a study of price differentials.

    PubMed

    Kjerstad, Egil

    2005-12-01

    Recent contributions in auction and bargaining theory suggest that a procurer should place more faith in the power of competition among alternative suppliers than in his or her own negotiating skill. Based on data from 216 contracts between procurers and suppliers of medical and surgical articles, we test whether auctions and bargaining result in significantly different prices. The main results are that auctions give 'thicker' markets compared with negotiations, as expected, but that auctions do not result in significantly lower prices compared with negotiations.

  4. Deformation effect simulation and optimization for double front axle steering mechanism

    NASA Astrophysics Data System (ADS)

    Wu, Jungang; Zhang, Siqin; Yang, Qinglong

    2013-03-01

    This paper research on tire wear problem of heavy vehicles with Double Front Axle Steering Mechanism from the flexible effect of Steering Mechanism, and proposes a structural optimization method which use both traditional static structural theory and dynamic structure theory - Equivalent Static Load (ESL) method to optimize key parts. The good simulated and test results show this method has high engineering practice and reference value for tire wear problem of Double Front Axle Steering Mechanism design.

  5. Health Auctions: a Valuation Experiment (HAVE) study protocol

    PubMed Central

    Kularatna, Sanjeewa; Petrie, Dennis; Scuffham, Paul A; Byrnes, Joshua

    2016-01-01

    Introduction Quality-adjusted life years are derived using health state utility weights which adjust for the relative value of living in each health state compared with living in perfect health. Various techniques are used to estimate health state utility weights including time-trade-off and standard gamble. These methods have exhibited limitations in terms of complexity, validity and reliability. A new composite approach using experimental auctions to value health states is introduced in this protocol. Methods and analysis A pilot study will test the feasibility and validity of using experimental auctions to value health states in monetary terms. A convenient sample (n=150) from a population of university staff and students will be invited to participate in 30 auction sets with a group of 5 people in each set. The 9 health states auctioned in each auction set will come from the commonly used EQ-5D-3L instrument. At most participants purchase 2 health states, and the participant who acquires the 2 ‘best’ health states on average will keep the amount of money they do not spend in acquiring those health states. The value (highest bid and average bid) of each of the 24 health states will be compared across auctions to test for reliability across auction groups and across auctioneers. A test retest will be conducted for 10% of the sample to assess reliability of responses for health states auctions. Feasibility of conducting experimental auctions to value health states will also be examined. The validity of estimated health states values will be compared with published utility estimates from other methods. This pilot study will explore the feasibility, reliability and validity in using experimental auction for valuing health states. Ethics and dissemination Ethical clearance was obtained from Griffith University ethics committee. The results will be disseminated in peer-reviewed journals and major international conferences. PMID:27056589

  6. The Double-Well Potential in Quantum Mechanics: A Simple, Numerically Exact Formulation

    ERIC Educational Resources Information Center

    Jelic, V.; Marsiglio, F.

    2012-01-01

    The double-well potential is arguably one of the most important potentials in quantum mechanics, because the solution contains the notion of a state as a linear superposition of "classical" states, a concept which has become very important in quantum information theory. It is therefore desirable to have solutions to simple double-well potentials…

  7. A Classroom Auction with Externalities: Applied to Mergers and Acquisitions

    ERIC Educational Resources Information Center

    Meister, J. Patrick; Anderson, Kyle J.

    2007-01-01

    The authors describe an in-class exercise in which students participate in an auction to buy US Airways. The exercise is based on events of late 1995, in which neither United nor American Airlines decided to bid for US Airways. Two teams of students participate in an English auction. Students learn that the equilibrium of the sequential game is…

  8. A Combinatorial Auction among Versatile Experts and Amateurs

    NASA Astrophysics Data System (ADS)

    Ito, Takayuki; Yokoo, Makoto; Matsubara, Shigeo

    Auctions have become an integral part of electronic commerce and a promising field for applying multi-agent technologies. Correctly judging the quality of auctioned goods is often difficult for amateurs, in particular, in Internet auctions. However, experts can correctly judge the quality of goods. In this situation, it is difficult to make experts tell the truth and attain an efficient allocation, since experts have a clear advantage over amateurs and they would not reveal their valuable information without some reward. In our previous work, we have succeeded in developing such auction protocols under the following two cases: (1) the case of a single-unit auction among experts and amateurs, and (2) the case of a combinatorial auction among single-skilled experts and amateurs. In this paper, we focus on versatile experts. Versatile experts have an interest in, and expert knowledge on the qualities of several goods. In the case of versatile experts, there would be several problems, e.g., free riding problems, if we simply extended the previous VCG-style auction protocol. Thus, in this paper, we employ PORF (price-oriented, rationing-free) protocol for designing our new protocol to realize a strategy-proof auction protocol for experts. In the protocol, the dominant strategy for experts is truth-telling. Also, for amateurs, truth-telling is the best response when two or more experts select the dominant strategy. Furthermore, the protocol is false-name-proof.

  9. Mechanical Response and Shear Initiation of Double-Base Propellants

    DTIC Science & Technology

    2009-08-01

    dynamic shear punch test using a modified split- Hopkinson bar. Varying the striker bar’s velocity and length controls the shear rate and duration. Shear...for double-base propellants and computational results of the shear punch test . For the simulations, the viscoSCRAM constitutive model was used to...initiation is determined based on their ability to predict the observed response from the dynamic shear punch test . 15. SUBJECT TERMS insensitive

  10. 77 FR 38803 - Mobility Fund Phase I Auction Updated Data For Auction 901

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-29

    ... subsequently released geographic information system (GIS) formats of the data shown in the interactive map. The... search function for AU Docket No. 12-25 on the Commission's Electronic Comment Filing System (ECFS) Web... with the release of Auction 901 Procedures Public Notice, the Bureaus released an interactive map...

  11. Detecting Fraud in Internet Auction Systems

    NASA Astrophysics Data System (ADS)

    Peng, Yanlin; Zhang, Linfeng; Guan, Yong

    Fraud compromises the thriving Internet auction market. Studies have shown that fraudsters often manipulate their reputations through sophisticated collusions with accomplices, enabling them to defeat the reputation-based feedback systems that are used to combat fraud. This paper presents an algorithm that can identify colluding fraudsters in real time. Experiments with eBay transaction data show that the algorithm has low false negative and false positive rates. Furthermore, the algorithm can identify fraudsters who are innocent at the time of the data collection, but engage in fraudulent transactions soon after they accumulate good feedback ratings.

  12. On The Physical Mechanism At The Origin Of Multiple Double Layers Appearance In Plasma

    SciTech Connect

    Dimitriu, D. G.; Gurlui, S.; Aflori, M.; Ivan, L. M.

    2006-01-15

    Double layer in plasma are nonlinear potential structures consisting of two adjacent layers of positive and negative space charges, respectively. Between these layers a potential jump exists, creating an electric field. A common way to obtain a double layer structure is to positively bias an electrode immersed into stable plasma. Under certain experimental conditions, a more complex structure in form of two or more subsequent double layers was observed, which was called multiple double layers. It appears as several bright and concentric plasma shells attached to the electrode. The successive double layers are located at the abrupt changes of luminosity between two adjacent plasma shells. However, if the electrode is large, the multiple double layers structure appears non-concentrically, as a network of plasma spots, near each other, almost equally distributed on the electrode surface. Each of the plasma spots is confined by an electrical double layer. Here, we will present experimental results on the appearance and dynamics of concentric, as well as non-concentric multiple double layers. The results prove that the same physical mechanism is at the origin of their appearance in plasma. In this mechanism, the electron-neutral impact excitations and ionizations play the key role.

  13. Attacks and Improvement of Quantum Sealed-Bid Auction with EPR Pairs

    NASA Astrophysics Data System (ADS)

    Liu, Wen-Jie; Wang, Fang; Ji, Sai; Qu, Zhi-Guo; Wang, Xiao-Jun

    2014-06-01

    Recently, an experimentally feasible three-party quantum sealed-bid auction protocol based on EPR pairs [Z.Y. Wang, Commun. Theor. Phys. 54 (2010) 997] was proposed. However, this study points out Wang's protocol cannot resist some internal bidders' attacks, such as the Twice-CNOT attack, the collusion attack. A malicious bidder can launch the Twice-CNOT attack to obtain the other's bid, or the dishonest auctioneer may collude with one bidder and help him/her win the action by changing his/her bid. For preventing against these attacks, a simple solution by using the QKD-based message encryption and a post-confirmation mechanism by adopting the hash function are proposed.

  14. Rationality, Irrationality and Escalating Behavior in Lowest Unique Bid Auctions

    PubMed Central

    Radicchi, Filippo; Baronchelli, Andrea; Amaral, Luís A. N.

    2012-01-01

    Information technology has revolutionized the traditional structure of markets. The removal of geographical and time constraints has fostered the growth of online auction markets, which now include millions of economic agents worldwide and annual transaction volumes in the billions of dollars. Here, we analyze bid histories of a little studied type of online auctions – lowest unique bid auctions. Similarly to what has been reported for foraging animals searching for scarce food, we find that agents adopt Lévy flight search strategies in their exploration of “bid space”. The Lévy regime, which is characterized by a power-law decaying probability distribution of step lengths, holds over nearly three orders of magnitude. We develop a quantitative model for lowest unique bid online auctions that reveals that agents use nearly optimal bidding strategies. However, agents participating in these auctions do not optimize their financial gain. Indeed, as long as there are many auction participants, a rational profit optimizing agent would choose not to participate in these auction markets. PMID:22279553

  15. Rationality, irrationality and escalating behavior in lowest unique bid auctions.

    PubMed

    Radicchi, Filippo; Baronchelli, Andrea; Amaral, Luís A N

    2012-01-01

    Information technology has revolutionized the traditional structure of markets. The removal of geographical and time constraints has fostered the growth of online auction markets, which now include millions of economic agents worldwide and annual transaction volumes in the billions of dollars. Here, we analyze bid histories of a little studied type of online auctions--lowest unique bid auctions. Similarly to what has been reported for foraging animals searching for scarce food, we find that agents adopt Lévy flight search strategies in their exploration of "bid space". The Lévy regime, which is characterized by a power-law decaying probability distribution of step lengths, holds over nearly three orders of magnitude. We develop a quantitative model for lowest unique bid online auctions that reveals that agents use nearly optimal bidding strategies. However, agents participating in these auctions do not optimize their financial gain. Indeed, as long as there are many auction participants, a rational profit optimizing agent would choose not to participate in these auction markets.

  16. The communications spectrum: Frequency allocations and auctions

    NASA Astrophysics Data System (ADS)

    Pritchard, Wilbur

    1997-01-01

    Demands on the communications spectrum have increased sharply because of the growth in radio communication services, the large bandwidths now required, and the rapid increases in world population. The problem will be exacerbated by the requirements of high definition television and the enormous amounts of information that will be transmitted by radio. The electromagnetic spectrum is a finite natural resource of great value used for emergency communications and military operations as well as for commercial purposes. Both government and the marketplace have proper roles in the allocation of its resources. There are no viable alternatives to international organizations such as the International Telecommunication Union or to agencies such as the Federal Communications Commission for the regulation of radio communication and the assignment of spectrum to essential public services. Although government auctions of spectrum are justifiable where there is no way to distinguish among commercial entities seeking to use the same bands for similar services, the practice is inherently inequitable and discourages development of new uses for the spectrum by removing investment protection. Recommended alternatives to auctions are: (1) lotteries, which keep assets and proceeds in the economy; and (2) ongoing charges for current as well as new users of the spectrum.

  17. Non-double-couple earthquake mechanisms at the Geysers geothermal area, California

    USGS Publications Warehouse

    Ross, A.; Foulger, G.R.; Julian, B.R.

    1996-01-01

    Inverting P- and S-wave polarities and P:SH amplitude ratios using linear programming methods suggests that about 20% of earthquakes at The Geysers geothermal area have significantly non-double-couple focal mechanisms, with explosive volumetric components as large as 33% of the seismic moment. This conclusion contrasts with those of earlier studies, which interpreted data in terms of double couples. The non-double-couple mechanisms are consistent with combined shear and tensile faulting, possibly caused by industrial water injection. Implosive mechanisms, which might be expected because of rapid steam withdrawal, have not been found. Significant compensated-linear-vector-dipole (CLVD) components in some mechanisms may indicate rapid fluid flow accompanying crack opening. Copyright 1996 by the American Geophysical Union.

  18. 78 FR 61350 - Tribal Mobility Fund Phase I Auction (Auction 902); Short-Form Application Filing Window...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-03

    ..., September 16, 2013, the Bureaus identified with an asterisk the items with one or more census blocks that... Auction 901 winning bidders have defaulted, the Bureaus removed the asterisks in the list that...

  19. Physical mechanisms of active control of sound transmission through rib stiffened double-panel structure

    NASA Astrophysics Data System (ADS)

    Ma, Xiyue; Chen, Kean; Ding, Shaohu; Yu, Haoxin

    2016-06-01

    This paper presents an analytical investigation on physical mechanisms of actively controlling sound transmission through a rib stiffened double-panel structure using point source in the cavity. The combined modal expansion and vibro-acoustic coupling methods are applied to establish the theoretical model of such active structure. Under the condition of minimizing radiated power of the radiating ribbed plate, the physical mechanisms are interpreted in detail from the point of view of modal couplings similar as that used in existed literatures. Results obtained demonstrate that the rule of sound energy transmission and the physical mechanisms for the rib stiffened double-panel structure are all changed, and affected by the coupling effects of the rib when compared with the analytical results obtained for unribbed double-panel case. By taking the coupling effects of the rib into considerations, the cavity modal suppression and rearrangement mechanisms obtained in existed investigations are modified and supplemented for the ribbed plate case, which gives a clear interpretation for the physical nature involved in the active rib stiffened double-panel structure.

  20. 31 CFR 356.23 - How are the auction results announced?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... conclusion of the auction, we will announce the auction results through a press release that is available on our Web site at http://www.treasurydirect.gov. (b) The press release will include such information...

  1. Competition in decentralized electricity markets: Three papers on electricity auctions

    NASA Astrophysics Data System (ADS)

    Harbord, David William Cameron

    This thesis consists of three self-contained papers on the analysis of electricity auctions written over a period of twelve years. The first paper models price competition in a decentralized wholesale market for electricity as a first-price, sealed-bid, multi-unit auction. In both the pure and mixed-strategy equilibria of the model, above marginal cost pricing and inefficient despatch of generating units occur. An alternative regulatory pricing rule is considered and it is shown that offering to supply at marginal cost can be induced as a dominant strategy for all firms. The second paper analyses strategic interaction between long-term contracts and price competition in the British electricity wholesale market, and confirms that forward contracts will tend to put downward pressure on spot market prices. A 'strategic commitment' motive for selling forward contracts is also identified: a generator may commit itself to bidding lower prices into the spot market in order to ensure that it will be despatched with its full capacity. The third paper characterizes bidding behavior and market outcomes in uniform and discriminatory electricity auctions. Uniform auctions result in higher average prices than discriminatory auctions, but the ranking in terms of productive efficiency is ambiguous. The comparative effects of other market design features, such as the number of steps in suppliers' bid functions, the duration of bids and the elasticity of demand are analyzed. The paper also clarifies some methodological issues in the analysis of electricity auctions. In particular we show that analogies with continuous share auctions are misplaced so long as firms are restricted to a finite number of bids.

  2. Nonsequential Two-Photon Double Ionization of Atoms: Identifying the Mechanism

    SciTech Connect

    Foerre, Morten; Nepstad, Raymond; Selstoe, Soelve

    2010-10-15

    We develop an approximate model for the process of direct (nonsequential) two-photon double ionization of atoms. Employing the model, we calculate (generalized) total cross sections as well as energy-resolved differential cross sections of helium for photon energies ranging from 39 to 54 eV. A comparison with results of ab initio calculations reveals that the agreement is at a quantitative level. We thus demonstrate that this complex ionization process can be described by the simple model, providing insight into the underlying physical mechanism. Finally, we use the model to calculate generalized cross sections for the two-photon double ionization of neon in the nonsequential regime.

  3. Energy transmission in a mechanically-linked double-wall structure coupled to an acoustic enclosure

    NASA Astrophysics Data System (ADS)

    Cheng, L.; Li, Y. Y.; Gao, J. X.

    2005-05-01

    The energy transmission in a mechanically linked double-wall structure into an acoustic enclosure is studied in this paper. Based on a fully coupled vibro-acoustic formulation, focus is put on investigating the effect of the air gap and mechanical links between the two panels on the energy transmission and noise insulation properties of such structures. An approximate formula reflecting the gap effect on the lower-order coupled frequencies of the system is proposed. A criterion, based on the ratio between the aerostatic stiffness of the gap cavity and the stiffness of the link, is proposed to predict the dominant transmitting path, with a view to provide guidelines for the design of appropriate control strategies. Numerical results reveal the existence of three distinct zones, within which energy transmission takes place following different mechanisms and transmitting paths. Corresponding effects on noise insulation properties of the double-wall structure are also investigated. .

  4. 9 CFR 2.76 - Records: Operators of auction sales and brokers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Records: Operators of auction sales..., DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Records § 2.76 Records: Operators of auction sales and brokers. (a) Every operator of an auction sale or broker shall make, keep, and maintain records or...

  5. Using Laboratory Experiments for Policymaking: An Example from the Georgia Irrigation Reduction Auction

    ERIC Educational Resources Information Center

    Cummings, Ronald G.; Holt, Charles A.; Laury, Susan K.

    2004-01-01

    In recent years, interest has been growing in policy applications of different auction systems. This paper reports a series of experiments that were used to design and implement an auction in a unique policymaking environment. In April 2000, the Georgia legislature passed a law that mandated that the state hold an auction in drought years to pay…

  6. Double-slit experiment with single wave-driven particles and its relation to quantum mechanics.

    PubMed

    Andersen, Anders; Madsen, Jacob; Reichelt, Christian; Rosenlund Ahl, Sonja; Lautrup, Benny; Ellegaard, Clive; Levinsen, Mogens T; Bohr, Tomas

    2015-07-01

    In a thought-provoking paper, Couder and Fort [Phys. Rev. Lett. 97, 154101 (2006)] describe a version of the famous double-slit experiment performed with droplets bouncing on a vertically vibrated fluid surface. In the experiment, an interference pattern in the single-particle statistics is found even though it is possible to determine unambiguously which slit the walking droplet passes. Here we argue, however, that the single-particle statistics in such an experiment will be fundamentally different from the single-particle statistics of quantum mechanics. Quantum mechanical interference takes place between different classical paths with precise amplitude and phase relations. In the double-slit experiment with walking droplets, these relations are lost since one of the paths is singled out by the droplet. To support our conclusions, we have carried out our own double-slit experiment, and our results, in particular the long and variable slit passage times of the droplets, cast strong doubt on the feasibility of the interference claimed by Couder and Fort. To understand theoretically the limitations of wave-driven particle systems as analogs to quantum mechanics, we introduce a Schrödinger equation with a source term originating from a localized particle that generates a wave while being simultaneously guided by it. We show that the ensuing particle-wave dynamics can capture some characteristics of quantum mechanics such as orbital quantization. However, the particle-wave dynamics can not reproduce quantum mechanics in general, and we show that the single-particle statistics for our model in a double-slit experiment with an additional splitter plate differs qualitatively from that of quantum mechanics.

  7. Damping mechanisms of single-clamped and prestressed double-clamped resonant polymer microbeams

    NASA Astrophysics Data System (ADS)

    Schmid, S.; Hierold, C.

    2008-11-01

    In this article, an investigation of the damping mechanisms of resonant single- and double-clamped polymer microbeams for a frequency range from 10 kHz to 5 MHz is presented. The suspended structures are made of SU-8, an epoxy-type photoresist, by means of a sacrificial layer technique. The vibration was measured with a laser-Doppler vibrometer in high vacuum at different temperatures and at atmospheric pressure. The influence of air damping in rarefied air was investigated and the intrinsic damping mechanisms were determined in high vacuum (p <0.05 Pa). After excluding a variety of possible damping factors, the dominant intrinsic dissipation mechanism of the single-clamped microbeams was understood to be the material damping with maximum quality factors (Q) of around 70 at 20 °C. Quality factors of up to 720 at 20 °C were measured for stringlike double-clamped microbeams, which suggest a different intrinsic damping mechanism than material loss. It is shown that internal damping mechanisms due to flexure and elongation have a small impact on the damping of stretched strings. Modeling the clamping loss based on the wave transmission into the suspended anchor plates indicates that it is the dominant intrinsic dissipation in the prestressed double-clamped microresonators. At atmospheric pressure it was shown that at low frequencies the quality factors of single-clamped and stringlike double-clamped microbeams are limited by the squeeze-film air damping. At high frequencies the quality factors are limited by the specific intrinsic damping. In between the two particular regions with a specific dominant damping mechanism the quality factors show a maximum.

  8. Model of Auctioneer Estimation of Swordtip Squid (Loligo edulis) Quality

    NASA Astrophysics Data System (ADS)

    Nakamura, Makoto; Matsumoto, Keisuke; Morimoto, Eiji; Ezoe, Satoru; Maeda, Toshimichi; Hirano, Takayuki

    The knowledge of experienced auctioneers regarding the circulation of marine products is an essential skill and is necessary for evaluating product quality and managing aspects such as freshness. In the present study, the ability of an auctioneer to quickly evaluate the freshness of swordtip squid (Loligo edulis) at fish markets was analyzed. Evaluation characteristics used by an auctioneer were analyzed and developed using a fuzzy logic model. Forty boxes containing 247 swordtip squid with mantles measuring 220 mm that had been evaluated and assigned to one of five quality categories by an auctioneer were used for the analysis and the modeling. The relationships between the evaluations of appearance, body color, and muscle freshness were statistically analyzed. It was found that a total of four indexes of the epidermis color strongly reflected evaluations of appearance: dispersion ratio of the head, chroma on the head-end mantle and the difference in the chroma and brightness of the mantle. The fuzzy logic model used these indexes for the antecedent-part of the linguistic rules. The results of both simulation and evaluations demonstrate that the model is robust, with the predicted results corresponding with more than 96% of the quality assignments of the auctioneers.

  9. 76 FR 1158 - Auction of 700 MHz Band Licenses Scheduled for July 19, 2011; Comment Sought on Competitive...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-07

    ... particular license). Under this proposal, the FCC Auction System interface will list the acceptable bid... and during the auction, through the Commission's Integrated Spectrum Auction System (FCC Auction System). 11. For purposes of complying with 47 CFR 1.2105(c), the Commission's rule prohibiting...

  10. Multi-unit auctions with budget-constrained bidders

    NASA Astrophysics Data System (ADS)

    Ghosh, Gagan Pratap

    In my dissertation, I investigate the effects of budget-constraints in multi-unit auctions. This is done in three parts. First, I analyze a case where all bidders have a common budget constraint. Precisely, I analyze an auction where two units of an object are sold at two simultaneous, sealed bid, first-price auctions, to bidders who have demand for both units. Bidders differ with respect to their valuations for the units. All bidders have an identical budget constraint which binds their ability to spend in the auction. I show that if valuation distribution is atom-less, then their does not exist any symmetric equilibrium in this auction game. In the second and third parts of my thesis, I analyze the sale of licenses for the right to drill for oil and natural gas in the Outer Continental Shelf (OCS) of the United States. These sales are conducted using simultaneous sealed-bid first-price auctions for multiple licenses, each representing a specific area (called a tract). Using aspects of observed bidding-behavior, I first make a prima facie case that bidders are budget-constrained in these auctions. In order to formalize this argument, I develop a simple extension of the standard model (where bidders differ in their valuations for the objects) by incorporating (random) budgets for the bidders. The auction-game then has a two-dimensional set of types for each player. I study the theoretical properties of this auction, assuming for simplicity that two units are being sold. I show that this game has an equilibrium in pure strategies that is symmetric with respect to the players and with respect to the units. The strategies are essentially pure in the sense that each bidder-type has a unique split (up to a permutation) of his budget between the two auctions. I then characterize the equilibrium in terms of the bid-distribution and iso-bid curves in the value-budget space. I derive various qualitative features of this equilibrium, among which are: (1) under mild

  11. Application for Single Price Auction Model (SPA) in AC Network

    NASA Astrophysics Data System (ADS)

    Wachi, Tsunehisa; Fukutome, Suguru; Chen, Luonan; Makino, Yoshinori; Koshimizu, Gentarou

    This paper aims to develop a single price auction model with AC transmission network, based on the principle of maximizing social surplus of electricity market. Specifically, we first formulate the auction market as a nonlinear optimization problem, which has almost the same form as the conventional optimal power flow problem, and then propose an algorithm to derive both market clearing price and trade volume of each player even for the case of market-splitting. As indicated in the paper, the proposed approach can be used not only for the price evaluation of auction or bidding market but also for analysis of bidding strategy, congestion effect and other constraints or factors. Several numerical examples are used to demonstrate effectiveness of our method.

  12. Mechanical properties and buckling behaviors of condensed double-walled carbon nanotubes.

    PubMed

    Zhang, Yingyan; Wang, Chien Ming; Tan, Vincent Beng Chye

    2009-08-01

    Molecular dynamics (MD) simulations are performed on condensed double-walled carbon nanotubes (CDWCNTs) to investigate the effects of compressed interwall spacings on their mechanical properties, in particular their buckling behavior under axial compression, torsion and bending. In CDWCNTs, the inner and outer nanotubes have diameters that are closer to each other than the nanotubes of conventional double-walled carbon nanotubes (DWCNTs). This leads to a smaller interwall spacing. The mechanical properties of the CDWCNTs, such as Young's modulus, interwall shear modulus, and the buckling strain under axial compression, torsion and bending are found to be greatly enhanced when compared with those of conventional DWCNTs. The enhancement is found to be inversely proportional to the interwall spacing.

  13. [Arc spectrum diagnostic and heat coupling mechanism analysis of double wire pulsed MIG welding].

    PubMed

    Liu, Yong-qiang; Li, Huan; Yang, Li-jun; Zheng, Kai; Gao, Ying

    2015-01-01

    A double wire pulsed MIG welding test system was built in the present paper, in order to analyze the heat-coupling mechanism of double wire pulsed MIG welding, and study are temperature field. Spectroscopic technique was used in diagnostic analysis of the are, plasma radiation was collected by using hollow probe method to obtain the arc plasma optical signal The electron temperature of double wire pulsed MIG welding arc plasma was calculated by using Boltzmann diagram method, the electron temperature distribution was obtained, a comprehensive analysis of the arc was conducted combined with the high speed camera technology and acquisition means of electricity signal. The innovation of this paper is the combination of high-speed camera image information of are and optical signal of arc plasma to analyze the coupling mechanism for dual arc, and a more intuitive analysis for are temperature field was conducted. The test results showed that a push-pull output was achieved and droplet transfer mode was a drop in a pulse in the welding process; Two arcs attracted each other under the action of a magnetic field, and shifted to the center of the arc in welding process, so a new heat center was formed at the geometric center of the double arc, and flowing up phenomenon occurred on the arc; Dual arc electronic temperature showed an inverted V-shaped distribution overall, and at the geometric center of the double arc, the arc electron temperature at 3 mm off the workpiece surface was the highest, which was 16,887.66 K, about 4,900 K higher than the lowest temperature 11,963.63 K.

  14. An Auctioning Reputation System Based on Anomaly Detection

    DTIC Science & Technology

    2005-01-01

    systems used by online auction houses do not address the concern of a buyer shopping for commodities—finding a good bargain. These systems do not provide...INTRODUCTION Online auction houses such as eBay have emerged as a conve- nient way to buy and sell items over the Internet. eBay alone has over 147 million...Pattern Classification. John Wiley and Sons, Inc., New York, NY, 2nd edition, 2000. [11] eBay Inc. Policy: Seller shill bidding. Published online at http

  15. Interpreting nonlinear vibrational spectroscopy with the classical mechanical analogs of double-sided Feynman diagrams.

    PubMed

    Noid, W G; Loring, Roger F

    2004-10-15

    Observables in coherent, multiple-pulse infrared spectroscopy may be computed from a vibrational nonlinear response function. This response function is conventionally calculated quantum-mechanically, but the challenges in applying quantum mechanics to large, anharmonic systems motivate the examination of classical mechanical vibrational nonlinear response functions. We present an approximate formulation of the classical mechanical third-order vibrational response function for an anharmonic solute oscillator interacting with a harmonic solvent, which establishes a clear connection between classical and quantum mechanical treatments. This formalism permits the identification of the classical mechanical analog of the pure dephasing of a quantum mechanical degree of freedom, and suggests the construction of classical mechanical analogs of the double-sided Feynman diagrams of quantum mechanics, which are widely applied to nonlinear spectroscopy. Application of a rotating wave approximation permits the analytic extraction of signals obeying particular spatial phase matching conditions from a classical-mechanical response function. Calculations of the third-order response function for an anharmonic oscillator coupled to a harmonic solvent are compared to numerically correct classical mechanical results.

  16. Tilting double-prism scanner driven by cam-based mechanism.

    PubMed

    Li, Anhu; Yi, Wanli; Sun, Wansong; Liu, Liren

    2015-06-20

    A pair of orthogonal tilting prisms has been explored in our previous work to perform the orientation and position tracking function with tracking accuracy better than submicroradian order. Crucial to the function implementation, however, is the real-time nonlinear control of the tilting angles of double prisms for tracking a given target trajectory. In previous papers [Proc. SPIE5892, 1-5 (2005).PSISDG0277-786X; Appl. Opt.45, 8063 (2006).PSISDG0277-786X; Proc. SPIE6709, 41 (2007).PSISDG0277-786X; Appl. Opt.51, 356 (2011).10.1364/AO.51.000356APOPAI1559-128X; Appl. Opt.53, 3712 (2014).10.1364/AO.53.003712APOPAI1559-128X], a new driving method by a cam-based mechanism, which can transfer the control problem to the design of corresponding cam configuration, is investigated. The design process of a cam-based mechanism is explained from the mapping relation between the tilting angles of a prism and the configuration curve of a corresponding cam. Based on the designed cam-based mechanism, a tracking error less than 0.375% is depicted between the tracking trajectory and the original one. Moreover, the dynamic characteristic of the tracking mechanism is discussed in detail as well as the impacts of different tilting speeds on the tracking trajectory. The proposed tracking mechanism of a tilting double-prism scanner can create a new avenue for passively tracking a given target.

  17. A double-lithography and double-reflow process and application to multi-pitch multi-height mechanical flexible interconnects

    NASA Astrophysics Data System (ADS)

    Zhang, Chaoqi; Yang, Hyung Suk; Bakir, Muhannad S.

    2017-02-01

    Wafer-level multi-pitch and multi-height mechanically flexible interconnects (MPMH MFIs) are demonstrated using a double-lithography and double-reflow process of a large array of sacrificial polymer domes with various heights (ranging from 26 µm to 66 µm). Using these domes, NiW MFIs with various pitches (ranging from 50 µm to 150 µm) are formed atop the multi-height domes using electroplating. The mechanical and electrical properties of the fabricated MPMH MFIs are characterized using indentation and four-point resistance measurements.

  18. A novel flexure-based microgripper with double amplification mechanisms for micro/nano manipulation

    NASA Astrophysics Data System (ADS)

    Sun, Xiantao; Chen, Weihai; Tian, Yanling; Fatikow, Sergej; Zhou, Rui; Zhang, Jianbin; Mikczinski, Manuel

    2013-08-01

    This paper describes the design, modeling, and testing of a novel flexure-based microgripper for a large jaw displacement with high resolution. Such a microgripper is indispensable in micro/nano manipulation. In achieving a large jaw displacement, double amplification mechanisms, namely, Scott-Russell mechanism and leverage mechanism arranged in series, are utilized to overcome the limited output of microgrippers driven by piezoelectric actuators. The mechanical performance of the microgripper is analyzed using the pseudo rigid body model approach. Finite element analysis is conducted to evaluate the performance and validate the established models for further optimum design of the microgripper. The prototype of the developed microgripper is fabricated, with which experimental tests are carried out. The experimental results show that the developed microgripper is capable of handling various sized micro-objects with a maximum jaw displacement of 134 μm and a high amplification ratio of 15.5.

  19. Steady-state mechanical squeezing in a double-cavity optomechanical system

    PubMed Central

    Wang, Dong-Yang; Bai, Cheng-Hua; Wang, Hong-Fu; Zhu, Ai-Dong; Zhang, Shou

    2016-01-01

    We study the physical properties of double-cavity optomechanical system in which the mechanical resonator interacts with one of the coupled cavities and another cavity is used as an auxiliary cavity. The model can be expected to achieve the strong optomechanical coupling strength and overcome the optomechanical cavity decay, simultaneously. Through the coherent auxiliary cavity interferences, the steady-state squeezing of mechanical resonator can be generated in highly unresolved sideband regime. The validity of the scheme is assessed by numerical simulation and theoretical analysis of the steady-state variance of the mechanical displacement quadrature. The scheme provides a platform for the mechanical squeezing beyond the resolved sideband limit and solves the restricted experimental bounds at present. PMID:27917939

  20. Overlapping mechanisms promote postsynaptic RAD-51 filament disassembly during meiotic double-strand break repair.

    PubMed

    Ward, Jordan D; Muzzini, Diego M; Petalcorin, Mark I R; Martinez-Perez, Enrique; Martin, Julie S; Plevani, Paolo; Cassata, Giuseppe; Marini, Federica; Boulton, Simon J

    2010-01-29

    Homologous recombination (HR) is essential for repair of meiotic DNA double-strand breaks (DSBs). Although the mechanisms of RAD-51-DNA filament assembly and strand exchange are well characterized, the subsequent steps of HR are less well defined. Here, we describe a synthetic lethal interaction between the C. elegans helicase helq-1 and RAD-51 paralog rfs-1, which results in a block to meiotic DSB repair after strand invasion. Whereas RAD-51-ssDNA filaments assemble at meiotic DSBs with normal kinetics in helq-1, rfs-1 double mutants, persistence of RAD-51 foci and genetic interactions with rtel-1 suggest a failure to disassemble RAD-51 from strand invasion intermediates. Indeed, purified HELQ-1 and RFS-1 independently bind to and promote the disassembly of RAD-51 from double-stranded, but not single-stranded, DNA filaments via distinct mechanisms in vitro. These results indicate that two compensating activities are required to promote postsynaptic RAD-51 filament disassembly, which are collectively essential for completion of meiotic DSB repair.

  1. Mechanical and microstructural characterization of single and double pass Aluminum AA6061 friction stir weld joints

    NASA Astrophysics Data System (ADS)

    Othman, N. H.; Shah, L. H.; Ishak, M.

    2015-12-01

    This study focuses on the effect of single pass (SP), double sided pass (DSP) and normal double pass (NDP) method on friction stir welding of aluminum AA6061. Two pieces of AA6061 alloy with thickness of 6 mm were friction stir welded by using conventional milling machine. The rotational speeds that were used in this study were 800 rpm, 1000 rpm and 1200 rpm, respectively. The welding speed is fixed to 100 mm/min. Microstructure observation of welded area was studied by using optical microscope. Tensile test and Vickers hardness test were used to evaluate the mechanical properties of this specimen. Mechanical property analysis results indicate that at low rotational speeds, defects such as surface lack of fill and tunneling in the welded area can be observed. Vickers hardness of specimens however did not vary much when rotational speed is varied. Welded specimens using single pass method shows higher tensile strength and hardness value compared to both double pass methods up to 180.61 MPa. Moreover, DSP showed better tensile test and hardness test compared to NDP method. The optimum parameters were found to be single pass method with 1200 rpm of rotational speed. Therefore economically sound to only perform SP method to obtain maximum tensile strength for AA6061 FSW with thickness of 6 mm.

  2. Thermo-mechanical and experimental analysis of double pass line heating

    NASA Astrophysics Data System (ADS)

    Biswas, Pankaj; Mandal, N. R.; Sha, O. P.; Mahapatra, M. M.

    2011-06-01

    The present investigation deals with process analysis of oxy-acetylene flame assisted double pass line heating for varying plate thickness. oxy-acetylene flame as the heat source for multi pass line heating to achieve 3-D bending of plates with varying thicknesses was studied. The oxy-acetylene flame was modeled as the moving heat source in the FEM analysis. The transient thermal histories were predicted taking into account the temperature dependent thermo-mechanical properties. A comparative study between single pass and double pass line heating residual deformation was also carried out. The temperature distribution and residual deformations predicted by the numerical model developed in the present work compared fairly well with those of the experimental ones.

  3. Making Marketing Principles Tangible: Online Auctions as Living Case Studies

    ERIC Educational Resources Information Center

    Wood, Charles M.; Suter, Tracy A.

    2004-01-01

    This article presents an effective course supplement for Principles of Marketing classes. An experiential project involving online auctions is offered to instructors seeking to create a more participatory student environment and an interactive teaching style. A number of learning points are illustrated that allow instructors to use an auction…

  4. Understanding Persuasive Online Sales Messages from eBay Auctions

    ERIC Educational Resources Information Center

    White, Barbara Jo; Clapper, Danial; Noel, Rita; Fortier, Jenny; Grabolosa, Pierre

    2007-01-01

    Online auctions are dominated by eBay, which started bringing together buyers and sellers in 1995. eBay product listings can easily be used in business communication courses to better understand online sales messages. One great advantage is that the vast majority of nearly 15 million listings a day are written and assembled by everyday consumers…

  5. 15. Detail view of the original auction podium in the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Detail view of the original auction podium in the 1937 arena (main section), with the west bleachers at the left, the north bleachers at the right, and the monitor roof structure, supported by posts, above; looking northwest - Ewing Livestock Market, South side of First Avenue North, 500 feet west of Route 724, Ewing, Lee County, VA

  6. Mechanisms governing the interfacial delamination of thermal barrier coating system with double ceramic layers

    NASA Astrophysics Data System (ADS)

    Xu, Rong; Fan, Xueling; Wang, T. J.

    2016-05-01

    A systematic study of factors affecting the interfacial delamination of thermal barrier coating system (TBCs) with double ceramic layers (DCL) is presented. Crack driving forces for delaminations at two weak interfaces are examined. The results show that a thicker outermost ceramic layer can induce dramatic increase in crack driving force and make the interface between two ceramic coatings become more prone to delamination. The behavior is shown to be more prominent in TBCs with stiffer outmost coating. The thickness ratio of two ceramic layers is an important parameter for controlling the failure mechanisms and determining the lifetime of DCL TBCs under inservice condition. By accounting for the influences of thickness ratio of two ceramic layers and interfacial fracture toughnesses of two involved interfaces, the fracture mechanism map of DCL TBCs has been constructed, in which different failure mechanisms are identified. The results quanlitatively agree with the aviliable experimental data.

  7. Disentangling the various Mechanisms of neutrinoless double beta decay to extract the neutrino mass

    NASA Astrophysics Data System (ADS)

    Vergados, J. D.

    2011-12-01

    It is well known that there exist many mechanisms that may contribute to neutrinoless double beta decay. By exploiting the fact that the associated nuclear matrix elements are target dependent we show that, given definite experimental results on a sufficient number of targets, one can determine or sufficiently constrain all lepton violating parameters including the mass term. As a specific example we show that, given the observation of the 0νββ-decay in three different nuclei, e.g. 76Ge, 100Mo and 130Te, and assuming just three active lepton number violating parameters, e.g. light and heavy neutrino mass mechanisms in left handed currents as well as R-parity breaking SUSY mechanism, one may determine all lepton violating parameters, provided that they are relatively real.

  8. Non-double-couple mechanisms of microearthquakes induced by hydraulic fracturing

    USGS Publications Warehouse

    Sileny, J.; Hill, D.P.; Eisner, L.; Cornet, F.H.

    2009-01-01

    We have inverted polarity and amplitude information of representative microearthquakes to investigate source mechanisms of seismicity induced by hydraulic fracturing in the Carthage Cotton Valley, east Texas, gas field. With vertical arrays of four and eight three-component geophones in two monitoring wells, respectively, we were able to reliably determine source mechanisms of the strongest events with the best signal-to-noise ratio. Our analysis indicates predominantly non-double-couple source mechanisms with positive volumetric component consistent with opening cracks oriented close to expected hydraulic fracture orientation. Our observations suggest the induced events are directly the result of opening cracks by fluid injection, in contrast to many previous studies where the seismicity is interpreted to be primarily shearing caused by pore pressure diffusion into the surrounding rock or associated with shear stresses created at the hydraulic fracture tip. Copyright 2009 by the American Geophysical Union.

  9. Double-archwire mechanics using temporary anchorage devices to relocate ectopically impacted maxillary canines.

    PubMed

    Kim, Seong-Hun; Choo, HyeRan; Hwang, Young-Sook; Chung, Kyu-Rhim

    2008-01-01

    This case report introduces a novel double archwire mechanics concept using orthodontic mini-implants and a miniplate to relocate ectopically impacted maxillary canines in a 14-year-old female with a Class III subdivision left malocclusion. The objective of this orthodontic treatment was to salvage the maxillary lateral incisors so they could be used for conservative restorations upon completion of the orthodontic treatment and to guide the impacted maxillary canines to their correct anatomical positions. The authors report that an iatrogenic root resorption of the maxillary lateral incisors, which is caused by a direct root contact between teeth during the active relocating procedure, can be minimized by using double-archwire mechanics. The optimal overbite, overjet, and occlusal interdigitation were achieved after the orthodontic treatment. The facial balance was also improved. Active orthodontic treatment lasted 26 months, and the results remained stable for 13 months after the removal of orthodontic appliances. This report also shows that the gingival margins of the relocated maxillary canines can be established without postorthodontic periodontal procedures when effective orthodontic mechanics are utilized to retain the canines in the alveolar bone and minimize any contact of the roots with gingival tissues during active relocation of the impacted maxillary canines.

  10. Shock Wave Boundary Layer Interaction Mechanism on a Double Wedge Geometry

    NASA Astrophysics Data System (ADS)

    Celik, Bayram; Barada, Mohammad Adel El Hajj Ali; Durna, Ahmet Selim

    2015-11-01

    A hypersonic test series by Swantek & Austin report complex shock wave boundary layer interaction mechanisms and unsteady surface heat flux from a double wedge geometry in a low enthalpy Mach 7 flow. In order to understand the physics of the flow and the heat transfer, we study the flow computationally and compare the results for the double wedge geometries, whose second angle is higher and lower than the maximum deflection angle at Mach 7. Apart from the numbers of comprehensive computational studies on the subject available in open literature, our study aims to describe the flow physics by taking the influence of both boundary layers that are formed on the two walls of the wedge into account. In addition to describing the flow and heat transfer mechanisms, we investigate the time for the flows to reach steady state. We evaluate the interaction mechanisms in term of instant and time average surface heat flux distributions. We perform all computations using a finite volume based compressible Navier-Stokes solver, rhoCentralFoam, which is one of the several compressible flow solvers of an open source software, openFOAM.

  11. Suppression mechanism of inter-tube transfer in double-wall carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Uryu, Seiji

    2005-03-01

    Double-wall carbon nanotubes have incommensurate lattice structure and are quasi-periodic[1,2]. Therefore, inter-tube transfer of electrons between incommensurate tubes is the key to understanding of double-wall tubes. Although some theoretical studies reported suppression of inter-tube transfer in multiwall tubes[3], the mechanism has not been well understood. The purpose of this paper is to clarify effects of inter-tube transfer in double-wall tubes. Using a tight-binding model length-dependence of conductance due to inter-tube transfer is calculated. The conductance is negligibly small in comparison to the conductance quantum and oscillates around an average which is approximately independent of the length. It is revealed based on the first-order perturbation theory that the result is attributed to quasi-periodic oscillation of position dependence of small local effective inter-tube coupling. [1] M. Kociak, K. Suenaga, K. Hirahara, Y. Saito, T. Nakahira, and S. Iijima, Phys. Rev. Lett. 89 (2002) 155501. [2] J. M. Zuo, I. Vartanyants, M. Gao, R. Zhang, and L. A. Nagahara, Science 300 (2003) 1419. [3] Y.-G. Yoon, P. Delaney, and S. G. Louie, Phys. Rev. B 66 (2002) 073407.

  12. Bolted Double-Lap Composite Joints Under Mechanical and Thermal Loading

    NASA Technical Reports Server (NTRS)

    Kradinov, V.; Barut, A.; Madenci, E.; Walker, Sandra P. (Technical Monitor)

    2000-01-01

    This study concerns the determination of the contact stresses and contact region around bolt holes and the bolt load distribution in single- and double-lap joints of composite laminates with arbitrarily located bolts under general mechanical loading conditions and uniform temperature change. The unknown contact stress distribution and contact region between the bolt and laminates and the interaction among the bolts require the bolt load distribution, as well as the contact stresses, to be as part of the solution. The present method is based on the complex potential theory and the variational formulation in order to account for bolt stiffness, bolt-hole clearance, and finite geometry of the composite laminates.

  13. Generic mechanisms of decoherence of quantum oscillations in magnetic double-well systems

    NASA Astrophysics Data System (ADS)

    M. Chudnovsky, Eugene

    2004-05-01

    Fundamental conservation laws mandate parameter-free generic mechanisms of decoherence of quantum oscillations in double-well systems. We consider two examples: tunneling of the magnetic moment in nanomagnets and tunneling between macroscopic current states in SQUIDs. In both cases the decoherence occurs via emission of phonons and photons at the oscillation frequency. We also show that in a system of identical qubits the decoherence greatly increases due to the superradiance of electromagnetic and sound waves. Our findings have important implications for building elements of quantum computers based upon nanomagnets and SQUIDs.

  14. Revealing a double-inversion mechanism for the F⁻+CH₃Cl SN2 reaction.

    PubMed

    Szabó, István; Czakó, Gábor

    2015-01-19

    Stereo-specific reaction mechanisms play a fundamental role in chemistry. The back-side attack inversion and front-side attack retention pathways of the bimolecular nucleophilic substitution (SN2) reactions are the textbook examples for stereo-specific chemical processes. Here, we report an accurate global analytic potential energy surface (PES) for the F(-)+CH₃Cl SN2 reaction, which describes both the back-side and front-side attack substitution pathways as well as the proton-abstraction channel. Moreover, reaction dynamics simulations on this surface reveal a novel double-inversion mechanism, in which an abstraction-induced inversion via a FH···CH₂Cl(-) transition state is followed by a second inversion via the usual [F···CH₃···Cl](-) saddle point, thereby opening a lower energy reaction path for retention than the front-side attack. Quasi-classical trajectory computations for the F(-)+CH₃Cl(ν1=0, 1) reactions show that the front-side attack is a fast direct, whereas the double inversion is a slow indirect process.

  15. Non-double-couple earthquake mechanisms at the Hengill-Grensdalur volcanic complex, southwest Iceland

    USGS Publications Warehouse

    Julian, B.R.; Miller, A.D.; Foulger, G.R.

    1997-01-01

    The Hengill-Grensdalur area in Iceland generates frequent small non-double-couple earthquakes with explosive volumetric components. We collected high quality three-component digital recordings of 4,000 earthquakes on a purpose-designed, 32-station network in 1991, and determined focal mechanisms for 100 of the best-recorded earthquakes by inverting amplitude ratios. Many of the mechanisms are consistent, within the errors, with simultaneous shear and tensile faulting, with tensile faults parallel to the local spreading ridge, and shear faulting similar to that in the South Iceland transform-fault zone. Some events cannot be explained by this model, however, and require other processes, such as crack closing and partial compensation of tensile cracks by fluid flow.

  16. Auction development for the price-based electric power industry

    NASA Astrophysics Data System (ADS)

    Dekrajangpetch, Somgiat

    The restructuring of the electric power industry is to move away from the cost-based monopolistic environment of the past to the priced-based competitive environment. As the electric power industry is restructuring in many places, there are still many problems that need to be solved. The work in this dissertation contributes to solve some of the electric power auction problems. The majority of this work is aimed to help develop good markets. A LaGrangian relaxation (LR) Centralized Daily Commitment Auction (CDCA) has been implemented. It has been shown that the solution might not be optimal nor fair to some generation companies (GENCOs) when identical or similar generating units participate in a LR CDCA based auction. Supporting information for bidding strategies on how to change unit data to enhance the chances of bid acceptance has been developed. The majority of this work is based on Single Period Commodity Auction (SPCA). Alternative structures for the SPCA are outlined. Whether the optimal solution is degenerated is investigated. Good pricing criteria are summarized and the pricing method following good pricing criteria is developed. Electricity is generally considered as a homogeneous product. When availability level is used as additional characteristic to distinct electricity, electricity can be considered a heterogeneous product. The procedure to trade electricity as a heterogeneous product is developed. The SPCA is formulated as a linear program. The basic IPLP algorithm has been extended so that sensitivity analysis can be performed as in the simplex method. Sensitivity analysis is used to determine market reach. Additionally, sensitivity analysis is used in combination with the investigation of historical auction results to provide raw data for power system expansion. Market power is a critical issue in electric power deregulation. Firms with market power have an advantage over other competitor firms in terms of market reach. Various approaches to

  17. Design and Promotion Strategy of Marketing Platform of Aquatic Auction based on Internet

    NASA Astrophysics Data System (ADS)

    Peng, Jianliang

    For the online trade and promotion of aquatic products and related materials through the network between supply and demand, the design content and effective promotional strategies of aquatic auctions online marketing platform is proposed in this paper. Design elements involve the location of customer service, the basic function of the platform including the purchase of general orders, online auctions, information dissemination, and recommendation of fine products, human services, and payment preferences. Based on network and mobile e-commerce transaction support, the auction platform makes the transaction of aquatic products well in advance. The results are important practical value for the design and application of online marketing platform of aquatic auction.

  18. A Gravitational Double-scattering Mechanism for Generating High-velocity Objects during Halo Mergers

    NASA Astrophysics Data System (ADS)

    Samsing, Johan

    2015-02-01

    We present a dynamical model that describes how halo particles can receive a significant energy kick from the merger between their own host halo and a target halo. This could provide a possible explanation for some high-velocity objects, including extended systems like globular clusters (GCs). In the model we especially introduce a double-scattering mechanism, where a halo particle receives a significant part of its total energy kick by first undergoing a gravitational deflection by the target halo and subsequently by its original host halo. This generates an energy kick that is due to the relative velocity between the halos during the deflections. We derive analytically the total kick energy of the particle, which is composed of energy from the double-scattering mechanism and tidal fields, as a function of its position in its original host halo just before merger. In the case of a 1:10 merger, we find that the presented mechanisms can easily generate particles with a velocity approximately two times the virial velocity of the target halo. This motivates us to suggest that the high velocity of the recently discovered GC HVGC-1 can be explained by a head-on halo merger. Finally, we illustrate the orbital evolution of high-velocity particles outside the virial sphere of the target halo by solving the equation of motion in an expanding universe. We find a sweet spot around a scale factor of 0.3-0.5 for ejecting particles into large orbits, which can easily reach beyond approximately five virial radii.

  19. A GRAVITATIONAL DOUBLE-SCATTERING MECHANISM FOR GENERATING HIGH-VELOCITY OBJECTS DURING HALO MERGERS

    SciTech Connect

    Samsing, Johan

    2015-02-01

    We present a dynamical model that describes how halo particles can receive a significant energy kick from the merger between their own host halo and a target halo. This could provide a possible explanation for some high-velocity objects, including extended systems like globular clusters (GCs). In the model we especially introduce a double-scattering mechanism, where a halo particle receives a significant part of its total energy kick by first undergoing a gravitational deflection by the target halo and subsequently by its original host halo. This generates an energy kick that is due to the relative velocity between the halos during the deflections. We derive analytically the total kick energy of the particle, which is composed of energy from the double-scattering mechanism and tidal fields, as a function of its position in its original host halo just before merger. In the case of a 1:10 merger, we find that the presented mechanisms can easily generate particles with a velocity approximately two times the virial velocity of the target halo. This motivates us to suggest that the high velocity of the recently discovered GC HVGC-1 can be explained by a head-on halo merger. Finally, we illustrate the orbital evolution of high-velocity particles outside the virial sphere of the target halo by solving the equation of motion in an expanding universe. We find a sweet spot around a scale factor of 0.3-0.5 for ejecting particles into large orbits, which can easily reach beyond approximately five virial radii.

  20. Using auctions for contracting with hospitals when quality matters.

    PubMed

    Mougeot, Michel; Naegelen, Florence

    2003-03-01

    This paper analyzes the problem of contracting with hospitals with hidden information when the number of patients wanting treatment depends on the quality of health care services offered. The optimal policy is characterized in the case of a single hospital. It is demonstrated that the regulator can reduce the information rent by decreasing the quality. When the regulator is assumed to be able to organize an auction for awarding the right to provide the service, we characterize the optimal auction and the first score tendering procedure implementing it. The regulator can reimburse a unit price per treated patient and let the hospital choose the level of quality. It is proved that the expected quality of health care services is greater and the expected payment is lower than in the monopoly case.

  1. Dynamic Characteristics of Mechanical Ventilation System of Double Lungs with Bi-Level Positive Airway Pressure Model

    PubMed Central

    Shen, Dongkai; Zhang, Qian

    2016-01-01

    In recent studies on the dynamic characteristics of ventilation system, it was considered that human had only one lung, and the coupling effect of double lungs on the air flow can not be illustrated, which has been in regard to be vital to life support of patients. In this article, to illustrate coupling effect of double lungs on flow dynamics of mechanical ventilation system, a mathematical model of a mechanical ventilation system, which consists of double lungs and a bi-level positive airway pressure (BIPAP) controlled ventilator, was proposed. To verify the mathematical model, a prototype of BIPAP system with a double-lung simulators and a BIPAP ventilator was set up for experimental study. Lastly, the study on the influences of key parameters of BIPAP system on dynamic characteristics was carried out. The study can be referred to in the development of research on BIPAP ventilation treatment and real respiratory diagnostics. PMID:27660646

  2. Determination of effective mechanical properties of a double-layer beam by means of a nano-electromechanical transducer

    SciTech Connect

    Hocke, Fredrik; Pernpeintner, Matthias; Gross, Rudolf; Zhou, Xiaoqing; Kippenberg, Tobias J.; Schliesser, Albert; Huebl, Hans

    2014-09-29

    We investigate the mechanical properties of a doubly clamped, double-layer nanobeam embedded into an electromechanical system. The nanobeam consists of a highly pre-stressed silicon nitride and a superconducting niobium layer. By measuring the mechanical displacement spectral density both in the linear and the nonlinear Duffing regime, we determine the pre-stress and the effective Young's modulus of the nanobeam. An analytical double-layer model quantitatively corroborates the measured values. This suggests that this model can be used to design mechanical multilayer systems for electro- and optomechanical devices, including materials controllable by external parameters such as piezoelectric, magnetostrictive, or in more general multiferroic materials.

  3. Auction and Game Theory Based Recommendations for DOD Acquisitions

    DTIC Science & Technology

    2015-03-24

    bidding behavior, they can arrive at the same results through experience and corporate lessons learned. Just as shoppers at a grocery store don’t...compute constrained optimization LaGrangians before checking out, yet economists still find that shoppers ’ purchasing behavior matches well with the...Mastronardi) can attest to the fact that even though second price and English oral auctions are common online (eBay), at county fairs, and other settings

  4. Novel HCN sorbents based on layered double hydroxides: sorption mechanism and performance.

    PubMed

    Zhao, Qian; Tian, Senlin; Yan, Linxia; Zhang, Qiulin; Ning, Ping

    2015-03-21

    Layered double hydroxides (LDHs) and layered double oxides (LDOs) have been prepared and used as sorbents for hydrogen cyanide (HCN). Based on results from sorbent optimization experiments, the optimal performance for HCN removal was found in Ni-Al LDH. As evidenced by fixed-bed sorption studies, the Ni-Al LDO with the greatest surface area showed better performance and outperformed products calcined at 200, 400, or 500 °C, whereas, the Ni-Al LDH showed a more twofold higher sorption capacity than the Ni-Al LDO. Investigation of the mechanisms between HCN and sorbents reveals that the HCN removal by the Ni-Al LDH and Ni-Al LDO leads to the formation of the complex anion, [Ni(CN)4](2-). Nevertheless, the [Ni(CN)4](2-) can enter interlayer region of the Ni-Al LDH due to its anion exchangeability, which endows this LDH with more binding sites, not only on its external surfaces, but also on its internal surfaces located in the interlayer region. In contrast, [Ni(CN)4](2-) were only adsorbed on the external surface of the Ni-Al LDO. As a result, the sorption capacity of the Ni-Al LDH for HCN is twice as high as that of the Ni-Al LDO, which is at 21.55 mg/g.

  5. Double negative elastic metamaterial design through electrical-mechanical circuit analogies.

    PubMed

    Pope, Simon A

    2013-07-01

    Previous studies into solid elastic metamaterials which have a simultaneously negative effective bulk modulus and density have proposed designs for materials with relatively narrow bandwidths, because of the reliance on resonators to provide the dispersive material properties. Some of the proposed novel applications for metamaterials, such as invisibility cloaks and sub-wavelength lenses, generally require materials with inherently larger bandwidths for practical exploitation. In this paper, a well-known electromagnetic metamaterial design is used together with the electrical-mechanical circuit analogies to propose a simultaneously double negative elastic metamaterial design which does not suffer from the narrow bandwidth constraints of previous designs. An interesting consequence of the proposed design is that it has an effective wavelength which asymptotically goes to infinity with frequency.

  6. [Plasma temperature calculation and coupling mechanism analysis of laser-double wire hybrid welding].

    PubMed

    Zheng, Kai; Li, Huan; Yang, Li-Jun; Gu, Xiao-Yan; Gao, Ying

    2013-04-01

    The plasma radiation of laser-double wire hybrid welding was collected by using fiber spectrometer, the coupling mechanism of arc with laser was studied through high-speed photography during welding process, and the temperature of hybrid plasma was calculated by using the method of Boltzmann plot. The results indicated that with laser hybrid, luminance was enhanced; radiation intensity became stronger; arc was attracted to the laser point; cross section contracted and arc was more stable. The laser power, welding current and arc-arc distance are important factors that have great influence on electron temperature. Increase in the laser power, amplification of welding current and reduction of arc-arc distance can all result in the rise of temperature.

  7. An experimental study of double-peeling mechanism inspired by biological adhesive systems

    NASA Astrophysics Data System (ADS)

    Heepe, Lars; Raguseo, Saverio; Gorb, Stanislav N.

    2017-02-01

    Double- (or multiple-) peeling systems consist of two (or numerous) tapes adhering to a substrate and having a common hinge, where the pulling force is applied. Biological systems, consisting of tape-like (or spatula-like) contact elements, are widely observed in adhesive pads of flies, beetles, spiders, and geckos. It was previously hypothesized and analytically modeled that the simultaneous use of two or more such tape-like contacts in the opposite movement of contralateral legs during ceiling locomotion leads to enhanced, robust, and stable overall attachment, if compared to independently working contact points. In this paper, this biological solution for smart adhesion is demonstrated in an experiment using elastic adhesive tapes. The obtained results not only aided in explaining the functional mechanism of biological adhesive systems, but also in providing an experimental proof for biological observations and previous theoretical models.

  8. DNA-PKcs structure suggests an allosteric mechanism modulating DNA double-strand break repair.

    PubMed

    Sibanda, Bancinyane L; Chirgadze, Dimitri Y; Ascher, David B; Blundell, Tom L

    2017-02-03

    DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a central component of nonhomologous end joining (NHEJ), repairing DNA double-strand breaks that would otherwise lead to apoptosis or cancer. We have solved its structure in complex with the C-terminal peptide of Ku80 at 4.3 angstrom resolution using x-ray crystallography. We show that the 4128-amino acid structure comprises three large structural units: the N-terminal unit, the Circular Cradle, and the Head. Conformational differences between the two molecules in the asymmetric unit are correlated with changes in accessibility of the kinase active site, which are consistent with an allosteric mechanism to bring about kinase activation. The location of KU80ct194 in the vicinity of the breast cancer 1 (BRCA1) binding site suggests competition with BRCA1, leading to pathway selection between NHEJ and homologous recombination.

  9. Structural Basis for Elastic Mechanical Properties of the DNA Double Helix

    PubMed Central

    Kim, Young-Joo; Kim, Do-Nyun

    2016-01-01

    In this article, we investigate the principal structural features of the DNA double helix and their effects on its elastic mechanical properties. We develop, in the pursuit of this purpose, a helical continuum model consisting of a soft helical core and two stiff ribbons wrapping around it. The proposed model can reproduce the negative twist-stretch coupling of the helix successfully as well as its global stretching, bending, and torsional rigidities measured experimentally. Our parametric study of the model using the finite element method further reveals that the stiffness of phosphate backbones is a crucial factor for the counterintuitive overwinding behavior of the duplex and its extraordinarily high torsional rigidity, the major-minor grooves augment the twist-stretch coupling, and the change of the helicity might be responsible for the transition from a negative to a positive twist-stretching coupling when a tensile force is applied to the duplex. PMID:27055239

  10. Nonmetallic rigid-flexible outer sheath with pneumatic shapelocking mechanism and double curvature structure.

    PubMed

    Zuo, Siyang; Masamune, Ken; Kuwana, Kenta; Tomikawa, Morimasa; Ieiri, Satoshi; Ohdaira, Takeshi; Hashizume, Makoto; Dohi, Takeyoshi

    2011-01-01

    Single port access (SPA) surgery is a laparoscopic procedure using only one transumbilical-placed port. Natural orifice transluminal endoscopic surgery (NOTES) offers the possibility of surgery without visible scars. To address the access and stability problems in SPA and NOTES, we developed a device called rigid-flexible outer sheath. This sheath can be switched between flexible and rigid modes by a novel pneumatic shapelocking mechanism, and it has a double curvature structure that enables it to flex in four directions at the distal end and three directions on the rigid-flexible shaft. The insertion part of the prototype is 300 mm long with a 20 mm outer diameter, and the part is equipped with four working channels. In vivo experiments using a swine show that the outer sheath has high potential for solving access and stability problems. We expect that the outer sheath will be useful for SPA and NOTES.

  11. A new, double-inversion mechanism of the F(-) + CH3Cl SN2 reaction in aqueous solution.

    PubMed

    Liu, Peng; Wang, Dunyou; Xu, Yulong

    2016-11-23

    Atomic-level, bimolecular nucleophilic substitution reaction mechanisms have been studied mostly in the gas phase, but the gas-phase results cannot be expected to reliably describe condensed-phase chemistry. As a novel, double-inversion mechanism has just been found for the F(-) + CH3Cl SN2 reaction in the gas phase [Nat. Commun., 2015, 6, 5972], here, using multi-level quantum mechanics methods combined with the molecular mechanics method, we discovered a new, double-inversion mechanism for this reaction in aqueous solution. However, the structures of the stationary points along the reaction path show significant differences from those in the gas phase due to the strong influence of solvent and solute interactions, especially due to the hydrogen bonds formed between the solute and the solvent. More importantly, the relationship between the two double-inversion transition states is not clear in the gas phase, but, here we revealed a novel intermediate complex serving as a "connecting link" between the two transition states of the abstraction-induced inversion and the Walden-inversion mechanisms. A detailed reaction path was constructed to show the atomic-level evolution of this novel double reaction mechanism in aqueous solution. The potentials of mean force were calculated and the obtained Walden-inversion barrier height agrees well with the available experimental value.

  12. Double-ionization mechanisms of the argon dimer in intense laser fields

    SciTech Connect

    Ulrich, B.; Vredenborg, A.; Malakzadeh, A.; Meckel, M.; Cole, K.; Jahnke, T.; Doerner, R.; Smolarski, M.; Chang, Z.

    2010-07-15

    We have measured the two-site double ionization of argon dimers by ultrashort laser pulses leading to fragmentation into two singly charged argon ions. Contrary to the expectations from a pure Coulomb explosion following rapid removal of one electron from each of the atoms, we find three distinct peaks in the kinetic energy release (KER) distribution. By measuring the angular distribution of the fragment ions and the vector momentum of one of the emitted electrons for circular and linear laser polarization, we are able to unravel the ionization mechanisms leading to the three features in the KER. The most abundant one results from tunnel ionization at one site followed by charge-enhanced tunnel ionization of the second atom. The second mechanism, which leads to a higher KER we identify as sequential tunnel ionization of both atoms accompanied by excitation. The third mechanism is present with linearly polarized light only. It is most likely a frustrated triple ionization, where the third electron does not escape but is trapped in a Rydberg state.

  13. Dense surface seismic data confirm non-double-couple source mechanisms induced by hydraulic fracturing

    USGS Publications Warehouse

    Pesicek, Jeremy; Cieślik, Konrad; Lambert, Marc-André; Carrillo, Pedro; Birkelo, Brad

    2016-01-01

    We have determined source mechanisms for nine high-quality microseismic events induced during hydraulic fracturing of the Montney Shale in Canada. Seismic data were recorded using a dense regularly spaced grid of sensors at the surface. The design and geometry of the survey are such that the recorded P-wave amplitudes essentially map the upper focal hemisphere, allowing the source mechanism to be interpreted directly from the data. Given the inherent difficulties of computing reliable moment tensors (MTs) from high-frequency microseismic data, the surface amplitude and polarity maps provide important additional confirmation of the source mechanisms. This is especially critical when interpreting non-shear source processes, which are notoriously susceptible to artifacts due to incomplete or inaccurate source modeling. We have found that most of the nine events contain significant non-double-couple (DC) components, as evident in the surface amplitude data and the resulting MT models. Furthermore, we found that source models that are constrained to be purely shear do not explain the data for most events. Thus, even though non-DC components of MTs can often be attributed to modeling artifacts, we argue that they are required by the data in some cases, and can be reliably computed and confidently interpreted under favorable conditions.

  14. Insect-like flapping wing mechanism based on a double spherical Scotch yoke

    PubMed Central

    Galiński, Cezary; Żbikowski, Rafał

    2005-01-01

    We describe the rationale, concept, design and implementation of a fixed-motion (non-adjustable) mechanism for insect-like flapping wing micro air vehicles in hover, inspired by two-winged flies (Diptera). This spatial (as opposed to planar) mechanism is based on the novel idea of a double spherical Scotch yoke. The mechanism was constructed for two main purposes: (i) as a test bed for aeromechanical research on hover in flapping flight, and (ii) as a precursor design for a future flapping wing micro air vehicle. Insects fly by oscillating (plunging) and rotating (pitching) their wings through large angles, while sweeping them forwards and backwards. During this motion the wing tip approximately traces a ‘figure-of-eight’ or a ‘banana’ and the wing changes the angle of attack (pitching) significantly. The kinematic and aerodynamic data from free-flying insects are sparse and uncertain, and it is not clear what aerodynamic consequences different wing motions have. Since acquiring the necessary kinematic and dynamic data from biological experiments remains a challenge, a synthetic, controlled study of insect-like flapping is not only of engineering value, but also of biological relevance. Micro air vehicles are defined as flying vehicles approximately 150 mm in size (hand-held), weighing 50–100 g, and are developed to reconnoitre in confined spaces (inside buildings, tunnels, etc.). For this application, insect-like flapping wings are an attractive solution and hence the need to realize the functionality of insect flight by engineering means. Since the semi-span of the insect wing is constant, the kinematics are spatial; in fact, an approximate figure-of-eight/banana is traced on a sphere. Hence a natural mechanism implementing such kinematics should be (i) spherical and (ii) generate mathematically convenient curves expressing the figure-of-eight/banana shape. The double spherical Scotch yoke design has property (i) by definition and achieves (ii) by

  15. Genetic mechanisms of allopolyploid speciation through hybrid genome doubling: novel insights from wheat (Triticum and Aegilops) studies.

    PubMed

    Matsuoka, Yoshihiro; Takumi, Shigeo; Nasuda, Shuhei

    2014-01-01

    Polyploidy, which arises through complex genetic and ecological processes, is an important mode of plant speciation. This review provides an overview of recent advances in understanding why plant polyploid species are so ubiquitous and diverse. We consider how the modern framework for understanding genetic mechanisms of speciation could be used to study allopolyploid speciation that occurs through hybrid genome doubling, that is, whole genome doubling of interspecific F1 hybrids by the union of male and female unreduced gametes. We outline genetic and ecological mechanisms that may have positive or negative impacts on the process of allopolyploid speciation through hybrid genome doubling. We also discuss the current status of studies on the underlying genetic mechanisms focusing on the wheat (Triticum and Aegilops) hybrid-specific reproductive phenomena that are well known but deserve renewed attention from an evolutionary viewpoint.

  16. 29 CFR 516.13 - Livestock auction employees exempt from overtime pay requirements under section 13(b)(13) of the...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Livestock auction employees exempt from overtime pay....13 Livestock auction employees exempt from overtime pay requirements under section 13(b)(13) of the... employee is employed both in agriculture and in connection with livestock auction operations: (a) The...

  17. 78 FR 11179 - Auction of Lower and Upper Paging Bands Licenses Scheduled for July 16, 2013; Comment Sought on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-15

    .... ADDRESSES: All filings in response to this public notice must refer to AU Docket No. 13-12. The Wireless... CONTACT: Wireless Telecommunications Bureau, Auctions and Spectrum Access Division: For auction legal...://wireless.fcc.gov/auctions/95/ , or by using the search function for AU Docket No. 13-12 on the...

  18. 7 CFR 29.75b - Display of baled flue-cured tobacco on auction warehouse floors in designated markets.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Display of baled flue-cured tobacco on auction... Inspection § 29.75b Display of baled flue-cured tobacco on auction warehouse floors in designated markets. Each lot of baled flue-cured tobacco displayed for sale on auction warehouse floors shall have...

  19. 77 FR 60690 - Auction of FM Broadcast Construction Permits Scheduled for March 26, 2013; Comment Sought on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-04

    ... amounts. Under this proposal, the FCC Auction System interface will list the acceptable bid amounts for... on the Commission's Electronic Comment Filing System (ECFS) Web page at http://www.fcc.gov/cgb/ecfs... Auction System (FCC Auction System). Bidders will also have the option of placing bids by...

  20. Theoretical study on the mechanism of double proton transfer in porphycene by path-integral molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Yoshikawa, Takehiro; Sugawara, Shuichi; Takayanagi, Toshiyuki; Shiga, Motoyuki; Tachikawa, Masanori

    2010-08-01

    Full-dimensional path-integral molecular dynamics simulations were performed to determine whether the double proton transfer tautomerization of porphycene is a concerted or a stepwise process. We employed an on-the-fly direct dynamics technique at the semiempirical PM6 method whose parameters were determined so as that the relative energies of the stationary points approximately reproduce previously reported electronic structure calculations. It was found that double proton transfer occurs dominantly through the concerted pathway via the second-order saddle point structure and that contribution of the stepwise mechanism increases with a temperature increase. Nuclear quantum effects play essential roles in determining the proton transfer mechanism.

  1. Robust Multi-unit Auction Protocol against False-name Bids

    NASA Astrophysics Data System (ADS)

    Yokoo, Makoto; Sakurai, Yuko; Matsubara, Shigeo

    This paper presents a new multi-unit auction protocol (IR protocol) that is robust against false-name bids. Internet auctions have become an integral part of Electronic Commerce and a promising field for applying agent and Artificial Intelligence technologies. Although the Internet provides an excellent infrastructure for executing auctions, the possibility of a new type of cheating called false-name bids has been pointed out. A false-name bid is a bid submitted under a fictitious name. A protocol called LDS has been developed for combinatorial auctions of multiple different items and has proven to be robust against false-name bids. Although we can modify the LDS protocol to handle multi-unit auctions, in which multiple units of an identical item are auctioned, the protocol is complicated and requires the auctioneer to carefully pre-determine the combination of bundles to obtain a high social surplus or revenue. For the auctioneer, our newly developed IR protocol is easier to use than the LDS, since the combination of bundles is automatically determined in a flexible manner according to the declared evaluation values of agents. The evaluation results show that the IR protocol can obtain a better social surplus than that obtained by the LDS protocol.

  2. Comment on "Cryptanalysis and improvement of the secure quantum sealed-bid auction with post confirmation"

    NASA Astrophysics Data System (ADS)

    Zhao, Zhangji; Wang, Weijia

    2014-11-01

    In a recent paper, an improvement of quantum sealed-bid auction protocol is proposed by introducing hash function. However, in this comment, it is shown that the improvement brings in other problems which would not complete the task of a sealed-bid auction fairly.

  3. 29 CFR 780.620 - Minimum wage for livestock auction work.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 3 2011-07-01 2011-07-01 false Minimum wage for livestock auction work. 780.620 Section 780.620 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR... for Exemption § 780.620 Minimum wage for livestock auction work. The application of the exemption...

  4. 29 CFR 780.620 - Minimum wage for livestock auction work.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 3 2012-07-01 2012-07-01 false Minimum wage for livestock auction work. 780.620 Section 780.620 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR... for Exemption § 780.620 Minimum wage for livestock auction work. The application of the exemption...

  5. 29 CFR 780.620 - Minimum wage for livestock auction work.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Minimum wage for livestock auction work. 780.620 Section 780.620 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR... for Exemption § 780.620 Minimum wage for livestock auction work. The application of the exemption...

  6. 29 CFR 780.620 - Minimum wage for livestock auction work.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 3 2013-07-01 2013-07-01 false Minimum wage for livestock auction work. 780.620 Section 780.620 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR... for Exemption § 780.620 Minimum wage for livestock auction work. The application of the exemption...

  7. 29 CFR 780.620 - Minimum wage for livestock auction work.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 3 2014-07-01 2014-07-01 false Minimum wage for livestock auction work. 780.620 Section 780.620 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR... for Exemption § 780.620 Minimum wage for livestock auction work. The application of the exemption...

  8. 31 CFR 356.22 - Does the Treasury have any limitations on auction awards?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Does the Treasury have any limitations on auction awards? 356.22 Section 356.22 Money and Finance: Treasury Regulations Relating to Money..., PUBLIC DEBT SERIES NO. 1-93) Determination of Auction Awards; Settlement § 356.22 Does the Treasury...

  9. 29 CFR 780.619 - Work “in connection with” livestock auction operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Work âin connection withâ livestock auction operations. 780... FAIR LABOR STANDARDS ACT Employment in Agriculture and Livestock Auction Operations Under the Section 13(b)(13) Exemption Requirements for Exemption § 780.619 Work “in connection with” livestock...

  10. 77 FR 69933 - Expanding the Economic and Innovation Opportunities of Spectrum Through Incentive Auctions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-21

    ...In the Notice of Proposed Rulemaking, ``Expanding the Economic and Innovation Opportunities of Spectrum Through Incentive Auctions'' (NPRM), released October 2, 2012, the Commission considers matters related to the implementation of Congress's mandate to conduct an incentive auction of broadcast television spectrum as set forth in the Middle Class Tax Relief and Job Creation Act of 2012......

  11. Sold! The Elementary Classroom Auction as Learning Tool of Communication and Economics

    ERIC Educational Resources Information Center

    Boyd, Josh; Boyd, Gina

    2014-01-01

    An auction, though an economic tool, is essentially a performance dependent on communication (Smith, 1989). The auctioneer dictates the pace, asks for bids, and acknowledges responses; the enterprise is controlled by a voice (Boyce, 2001). Bidders must listen and respond strategically to the communication of the people around them. An auction…

  12. 30 CFR 585.220 - What auction format may BOEM use in a lease sale?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... INTERIOR OFFSHORE RENEWABLE ENERGY AND ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF Issuance of OCS Renewable Energy Leases Competitive Lease Award Process § 585.220 What auction format may... award renewable energy leases and will use one of the following auction formats, as determined...

  13. 30 CFR 585.220 - What auction format may BOEM use in a lease sale?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... INTERIOR OFFSHORE RENEWABLE ENERGY AND ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF Issuance of OCS Renewable Energy Leases Competitive Lease Award Process § 585.220 What auction format may... award renewable energy leases and will use one of the following auction formats, as determined...

  14. 30 CFR 585.220 - What auction format may BOEM use in a lease sale?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... INTERIOR OFFSHORE RENEWABLE ENERGY AND ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF Issuance of OCS Renewable Energy Leases Competitive Lease Award Process § 585.220 What auction format may... award renewable energy leases and will use one of the following auction formats, as determined...

  15. 30 CFR 285.220 - What auction format may MMS use in a lease sale?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OFFSHORE RENEWABLE ENERGY ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF Issuance of OCS Renewable Energy Leases Competitive Lease Award Process § 285.220 What auction format may MMS use... renewable energy leases and will use one of the following auction formats, as determined through the...

  16. 30 CFR 285.220 - What auction format may MMS use in a lease sale?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE RENEWABLE ENERGY ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF Issuance of OCS Renewable Energy Leases Competitive Lease Award Process § 285... competitive auctions to award renewable energy leases and will use one of the following auction formats,...

  17. 77 FR 38061 - Mobility Fund Phase I Auction Supplemental Short-Form Instructions and Other Information

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-26

    ... Phase I Auction for completing FCC Form 180, announce the availability of certain updated files and..., please provide the appropriate FCC document number, for example, DA 12-947. The Supplemental Filing... site: http://wireless.fcc.gov/auctions/901/ or by using the search function for AU Docket No. 12-25...

  18. Are Structural Estimates of Auction Models Reasonable? Evidence from Experimental Data

    ERIC Educational Resources Information Center

    Bajari, Patrick; Hortacsu, Ali

    2005-01-01

    Recently, economists have developed methods for structural estimation of auction models. Many researchers object to these methods because they find the strict rationality assumptions to be implausible. Using bid data from first-price auction experiments, we estimate four alternative structural models: (1) risk-neutral Bayes-Nash, (2) risk-averse…

  19. A three-dimensional statistical mechanical model of folding double-stranded chain molecules

    NASA Astrophysics Data System (ADS)

    Zhang, Wenbing; Chen, Shi-Jie

    2001-05-01

    Based on a graphical representation of intrachain contacts, we have developed a new three-dimensional model for the statistical mechanics of double-stranded chain molecules. The theory has been tested and validated for the cubic lattice chain conformations. The statistical mechanical model can be applied to the equilibrium folding thermodynamics of a large class of chain molecules, including protein β-hairpin conformations and RNA secondary structures. The application of a previously developed two-dimensional model to RNA secondary structure folding thermodynamics generally overestimates the breadth of the melting curves [S-J. Chen and K. A. Dill, Proc. Natl. Acad. Sci. U.S.A. 97, 646 (2000)], suggesting an underestimation for the sharpness of the conformational transitions. In this work, we show that the new three-dimensional model gives much sharper melting curves than the two-dimensional model. We believe that the new three-dimensional model may give much improved predictions for the thermodynamic properties of RNA conformational changes than the previous two-dimensional model.

  20. Characterization and mechanism of glass microwelding by double-pulse ultrafast laser irradiation.

    PubMed

    Wu, Sizhu; Wu, Dong; Xu, Jian; Hanada, Yasutaka; Suganuma, Ryo; Wang, Haiyu; Makimura, Testuya; Sugioka, Koji; Midorikawa, Katsumi

    2012-12-17

    We investigated the physical mechanism of high-efficiency glass microwelding by double-pulse ultrafast laser irradiation by measuring the dependences of the size of the heat-affected zone and the bonding strength on the delay time between the two pulses for delay time up to 80 ns. The size of the heat-affected zone increases rapidly when the delay time is increased from 0 to 12.5 ps. It then decreases dramatically when the delay time is further increased to 30 ps. It has a small peak around 100 ps. For delay time up to 40 ns, the size of the heat-affected zone exceeds that for a delay time of 0 ps, whereas for delay time over 60 ps, it becomes smaller than that for a delay time of 0 ps. The bonding strength exhibits the same tendency. The underlying physical mechanism is discussed in terms of initial electron excitation by the first pulse and subsequent excitation by the second pulse: specifically, the first pulse induces multiphoton ionization or tunneling ionization, while the second pulse induces electron heating or avalanche ionization or the second pulse is absorbed by the localized state. Transient absorption of glass induced by the ultrafast laser pulse was analyzed by an ultrafast pump-probe technique. We found that the optimum pulse energy ratio is unity. These results provide new insights into high-efficiency ultrafast laser microwelding of glass and suggest new possibilities for further development of other ultrafast laser processing techniques.

  1. Telomere Dysfunction Triggers Palindrome Formation Independently of Double-Strand Break Repair Mechanisms

    PubMed Central

    Raykov, Vasil; Marvin, Marcus E.; Louis, Edward J.; Maringele, Laura

    2016-01-01

    Inverted chromosome duplications or palindromes are linked with genetic disorders and malignant transformation. They are considered by-products of DNA double-strand break (DSB) repair: the homologous recombination (HR) and the nonhomologous end joining (NHEJ). Palindromes near chromosome ends are often triggered by telomere losses. An important question is to what extent their formation depends upon DSB repair mechanisms. Here we addressed this question using yeast genetics and comparative genomic hybridization. We induced palindrome formation by passaging cells lacking any form of telomere maintenance (telomerase and telomere recombination). Surprisingly, we found that DNA ligase 4, essential for NHEJ, did not make a significant contribution to palindrome formation induced by telomere losses. Moreover RAD51, important for certain HR-derived mechanisms, had little effect. Furthermore RAD52, which is essential for HR in yeast, appeared to decrease the number of palindromes in cells proliferating without telomeres. This study also uncovered an important role for Rev3 and Rev7 (but not for Pol32) subunits of polymerase ζ in the survival of cells undergoing telomere losses and forming palindromes. We propose a model called short-inverted repeat-induced synthesis in which DNA synthesis, rather than DSB repair, drives the inverted duplication triggered by telomere dysfunction. PMID:27334270

  2. Mechanisms and Consequences of Double-strand DNA Break Formation in Chromatin

    PubMed Central

    Cannan, Wendy J.; Pederson, David S.

    2016-01-01

    All organisms suffer double-strand breaks (DSBs) in their DNA as a result of exposure to ionizing radiation. DSBs can also form when replication forks encounter DNA lesions or repair intermediates. The processing and repair of DSBs can lead to mutations, loss of heterozygosity, and chromosome rearrangements that result in cell death or cancer. The most common pathway used to repair DSBs in metazoans (non-homologous DNA end joining) is more commonly mutagenic than the alternative pathway (homologous recombination mediated repair). Thus, factors that influence the choice of pathways used DSB repair can affect an individual’s mutation burden and risk of cancer. This review describes radiological, chemical and biological mechanisms that generate DSBs, and discusses the impact of such variables as DSB etiology, cell type, cell cycle, and chromatin structure on the yield, distribution, and processing of DSBs. The final section focuses on nucleosome-specific mechanisms that influence DSB production, and the possible relationship between higher order chromosome coiling and chromosome shattering (chromothripsis). PMID:26040249

  3. Experimental evidence of a mechanical coupling between layers in an individual double-walled carbon nanotube.

    PubMed

    Levshov, D; Than, T X; Arenal, R; Popov, V N; Parret, R; Paillet, M; Jourdain, V; Zahab, A A; Michel, T; Yuzyuk, Yu I; Sauvajol, J-L

    2011-11-09

    We perform transmission electron microscopy, electron diffraction, and Raman scattering experiments on an individual suspended double-walled carbon nanotube (DWCNT). The first two techniques allow the unambiguous determination of the DWCNT structure: (12,8)@(16,14). However, the low-frequency features in the Raman spectra cannot be connected to the derived layer diameters d by means of the 1/d power law, widely used for the diameter dependence of the radial-breathing mode of single-walled nanotubes. We discuss this disagreement in terms of mechanical coupling between the layers of the DWCNT, which results in collective vibrational modes. Theoretical predictions for the breathing-like modes of the DWCNT, originating from the radial-breathing modes of the layers, are in a very good agreement with the observed Raman spectra. Moreover, the mechanical coupling qualitatively explains the observation of Raman lines of breathing-like modes, whenever only one of the layers is in resonance with the laser energy.

  4. 7 CFR 1955.131 - Auctioneers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... REGULATIONS (CONTINUED) PROPERTY MANAGEMENT Disposal of Inventory Property Use of Contractors to Dispose of..., location, advertising, broker cooperation, innovations, mechanics of sale, sample advertising,...

  5. 7 CFR 1955.131 - Auctioneers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... REGULATIONS (CONTINUED) PROPERTY MANAGEMENT Disposal of Inventory Property Use of Contractors to Dispose of..., location, advertising, broker cooperation, innovations, mechanics of sale, sample advertising,...

  6. Pricing strategies, the strength of bidding intentions, and online auction performance: a cross-cultural study.

    PubMed

    Peng, Yu-Shu; Jan, Lih-Tsyr

    2009-10-01

    Over the past decade, electronic markets based on the Internet, particularly online auctions, have become popular venues for conducting business. Previous studies often focused on the construction of the best bidding model, while few studies have tried to integrate multiple pricing strategies to predict the probability of closing an auction and the price premium. This study constructs a mediated model to examine the relationship among pricing strategies, the strength of bidding intentions, and online auction performance. The sample consists of 1,055 auctions of iPod MP3 players from eBay Web sites in Hong Kong, Singapore, Belgium, and France. Empirical results show that the pricing strategies directly influence both the probability of closing an auction and the level of price premium. The pricing strategies also indirectly influence the price premium through the mediating effect of the strength of bidding intentions.

  7. Differences and correlations in knee and hip mechanics during single-leg landing, single-leg squat, double-leg landing, and double-leg squat tasks.

    PubMed

    Donohue, Michael R; Ellis, Samantha M; Heinbaugh, Erika M; Stephenson, Mitchell L; Zhu, Qin; Dai, Boyi

    2015-01-01

    Landing and squat tasks have been utilized to assess lower extremity biomechanics associated with anterior cruciate ligament loading and injury risks. The purpose of this study was to identify the differences and correlations in knee and hip mechanics during a single-leg landing, a single-leg squat, a double-leg landing, and a double-leg squat. Seventeen male and 17 female recreational athletes performed landings and squats when kinematic and kinetic data were collected. ANOVAs showed significant differences (p < 0.00001) for maximum knee flexion angles, maximum hip flexion angles, maximum knee abduction angles, maximum hip adduction angles, and maximum external knee abduction moments among squats and landings. For maximum knee and hip flexion angles, significant correlations (r ≥ 0.5, p ≤ 0.003) were observed between the two landings and between the two squats. For maximum knee abduction and hip adduction angles and maximum external knee abduction moments, significant correlations were mostly found between the two landings, and between the single-leg squat and landings (r ≥ 0.54, p ≤ 0.001). Individuals are likely to demonstrate different profiles of injury risks when screened using different tasks. While a double-leg landing should be considered as a priority in screening, a single-leg squat may be used as a surrogate to assess frontal plane motion and loading.

  8. Exploring the mechanism of IR-UV double-resonance for quantitative spectroscopy of protonated polypeptides and proteins.

    PubMed

    Nagornova, Natalia S; Rizzo, Thomas R; Boyarkin, Oleg V

    2013-06-03

    Spectroscopic fingerprint: Infrared–ultraviolet double resonance photodissociation is used for conformational assignment of the electronic spectra of a cold protonated decapeptide (see picture). A mechanism of the IR–UV depletion spectroscopy is proposed and a procedure of using it for measurements of absolute absorption cross-sections of vibrational transitions is elaborated.

  9. Mechanisms of DNA Packaging by Large Double-Stranded DNA Viruses

    PubMed Central

    Rao, Venigalla B.; Feiss, Michael

    2016-01-01

    Translocation of viral double-stranded DNA (dsDNA) into the icosahedral prohead shell is catalyzed by TerL, a motor protein that has ATPase, endonuclease, and translocase activities. TerL, following endonucleolytic cleavage of immature viral DNA concatemer recognized by TerS, assembles into a pentameric ring motor on the prohead’s portal vertex and uses ATP hydrolysis energy for DNA translocation. TerL’s N-terminal ATPase is connected by a hinge to the C-terminal endonuclease. Inchworm models propose that modest domain motions accompanying ATP hydrolysis are amplified, through changes in electrostatic interactions, into larger movements of the C-terminal domain bound to DNA. In phage φ29, four of the five TerL subunits sequentially hydrolyze ATP, each powering translocation of 2.5 bp. After one viral genome is encapsidated, the internal pressure signals termination of packaging and ejection of the motor. Current focus is on the structures of packaging complexes and the dynamics of TerL during DNA packaging, endonuclease regulation, and motor mechanics. PMID:26958920

  10. Anti-Capture to the Continuum via a Double Collision Mechanism in (e,2e) Collisions

    NASA Astrophysics Data System (ADS)

    Ward, S. J.; Roth, E. G.; Guo, B. N.; Golden, D. E.; Mueller, D. W.

    1997-04-01

    Recently, anti-capture to the continuum occurring via the (Thomas) double collision mechanism has been reported.(D. E. Golden, J. Xu, D. W. Mueller and J. Bernhard, Nucl. Inst. and Meth. in Phys. Res. B 99) 202 (1995).^,(D. E. Golden, Z. Xu, J. Bernhard and D. W. Mueller, J. Phys. B: At. Mol. Opt. Phys. 29) 3741 (1996). The doubly differential cross section was measured in coplanar geometry for electron-impact ionization of argon at a 1000 eV incident energy. The cross section is differential with respect to the solid angle of the ejected electron and scattered electron. The detector (split anode detector) measures the two outgoing electrons at approximately the same angle. Both a sharp dip---the signature of anti-electron capture to the continuum---and the Thomas peak were observed in the cross section. We computed the doubly differential cross section for electron-impact ionization of hydrogen. This was done by including in the Bethe-Born approximation a normalization factor that approximately incorporates electron-electron interactions in the final state. We considered hydrogen both in the ground state and the 2p excited state and were able to reproduce the main features of the measurements.

  11. Sp1 facilitates DNA double-strand break repair through a nontranscriptional mechanism.

    PubMed

    Beishline, Kate; Kelly, Crystal M; Olofsson, Beatrix A; Koduri, Sravanthi; Emrich, Jacqueline; Greenberg, Roger A; Azizkhan-Clifford, Jane

    2012-09-01

    Sp1 is a ubiquitously expressed transcription factor that is phosphorylated by ataxia telangiectasia mutated kinase (ATM) in response to ionizing radiation and H(2)O(2). Here, we show by indirect immunofluorescence that Sp1 phosphorylated on serine 101 (pSp1) localizes to ionizing radiation-induced foci with phosphorylated histone variant γH2Ax and members of the MRN (Mre11, Rad50, and Nbs1) complex. More precise analysis of occupancy of DNA double-strand breaks (DSBs) by chromatin immunoprecipitation (ChIP) shows that Sp1, like Nbs1, resides within 200 bp of DSBs. Using laser microirradiation of cells, we demonstrate that pSp1 is present at DNA DSBs by 7.5 min after induction of damage and remains at the break site for at least 8 h. Depletion of Sp1 inhibits repair of site-specific DNA breaks, and the N-terminal 182-amino-acid peptide, which contains targets of ATM kinase but lacks the zinc finger DNA binding domain, is phosphorylated, localizes to DSBs, and rescues the repair defect resulting from Sp1 depletion. Together, these data demonstrate that Sp1 is rapidly recruited to the region immediately adjacent to sites of DNA DSBs and is required for DSB repair, through a mechanism independent of its sequence-directed transcriptional effects.

  12. Large displacement behavior of double parallelogram flexure mechanisms with underconstraint eliminators

    DOE PAGES

    Panas, Robert M.

    2016-06-23

    This paper presents a new analytical method for predicting the large displacement behavior of flexural double parallelogram (DP) bearings with underconstraint eliminator (UE) linkages. This closed-form perturbative Euler analysis method is able to – for the first time – directly incorporate the elastomechanics of a discrete UE linkage, which is a hybrid flexure element that is linked to ground as well as both stages on the bearing. The models are used to understand a nested linkage UE design, however the method is extensible to other UE linkages. Design rules and figures-of-merit are extracted from the analysis models, which provide powerfulmore » tools for accelerating the design process. The models, rules and figures-of-merit enable the rapid design of a UE for a desired large displacement behavior, as well as providing a means for determining the limits of UE and DP structures. This will aid in the adoption of UE linkages into DP bearings for precision mechanisms. Models are generated for a nested linkage UE design, and the performance of this DP with UE structure is compared to a DP-only bearing. As a result, the perturbative Euler analysis is shown to match existing theories for DP-only bearings with distributed compliance within ≈2%, and Finite Element Analysis for the DP with UE bearings within an average 10%.« less

  13. Large displacement behavior of double parallelogram flexure mechanisms with underconstraint eliminators

    SciTech Connect

    Panas, Robert M.

    2016-06-23

    This paper presents a new analytical method for predicting the large displacement behavior of flexural double parallelogram (DP) bearings with underconstraint eliminator (UE) linkages. This closed-form perturbative Euler analysis method is able to – for the first time – directly incorporate the elastomechanics of a discrete UE linkage, which is a hybrid flexure element that is linked to ground as well as both stages on the bearing. The models are used to understand a nested linkage UE design, however the method is extensible to other UE linkages. Design rules and figures-of-merit are extracted from the analysis models, which provide powerful tools for accelerating the design process. The models, rules and figures-of-merit enable the rapid design of a UE for a desired large displacement behavior, as well as providing a means for determining the limits of UE and DP structures. This will aid in the adoption of UE linkages into DP bearings for precision mechanisms. Models are generated for a nested linkage UE design, and the performance of this DP with UE structure is compared to a DP-only bearing. As a result, the perturbative Euler analysis is shown to match existing theories for DP-only bearings with distributed compliance within ≈2%, and Finite Element Analysis for the DP with UE bearings within an average 10%.

  14. Multiple mechanisms contribute to double-strand break repair at rereplication forks in Drosophila follicle cells

    PubMed Central

    Alexander, Jessica L.; Beagan, Kelly; Orr-Weaver, Terry L.; McVey, Mitch

    2016-01-01

    Rereplication generates double-strand breaks (DSBs) at sites of fork collisions and causes genomic damage, including repeat instability and chromosomal aberrations. However, the primary mechanism used to repair rereplication DSBs varies across different experimental systems. In Drosophila follicle cells, developmentally regulated rereplication is used to amplify six genomic regions, two of which contain genes encoding eggshell proteins. We have exploited this system to test the roles of several DSB repair pathways during rereplication, using fork progression as a readout for DSB repair efficiency. Here we show that a null mutation in the microhomology-mediated end-joining (MMEJ) component, polymerase θ/mutagen-sensitive 308 (mus308), exhibits a sporadic thin eggshell phenotype and reduced chorion gene expression. Unlike other thin eggshell mutants, mus308 displays normal origin firing but reduced fork progression at two regions of rereplication. We also find that MMEJ compensates for loss of nonhomologous end joining to repair rereplication DSBs in a site-specific manner. Conversely, we show that fork progression is enhanced in the absence of both Drosophila Rad51 homologs, spindle-A and spindle-B, revealing homologous recombination is active and actually impairs fork movement during follicle cell rereplication. These results demonstrate that several DSB repair pathways are used during rereplication in the follicle cells and their contribution to productive fork progression is influenced by genomic position and repair pathway competition. Furthermore, our findings illustrate that specific rereplication DSB repair pathways can have major effects on cellular physiology, dependent upon genomic context. PMID:27849606

  15. Research on the Mechanical Properties of "Z" Type Double-Decker Ball Bearings.

    PubMed

    Yu, Chengtao; Xu, Longxiang; Yu, Xudong

    2014-01-01

    The mechanical model of a "Z" type double-decker ball bearing under the action of radial load is established in this paper on the basis of the Hertz contact theory. According to the security contact angle theory, the influences of inner and outer bearings' internal clearances on the bearing's static load carrying capacity, radial deformation, radial stiffness, and load distribution of balls are analyzed. This model is verified in both stationary and rotational loading experiments. Moreover, the simulation results show that the static load carrying capacity of Z type bearing is smaller than that of either inner bearing or outer bearing that is contributed to compose the Z type bearing. The static load carrying capacity of a Z type bearing reduces with the increase of the inner and outer bearings' internal clearance. These simulation results also indicate that the contact angle of the maximum loaded ball in the outer bearing easily exceeds its security contact angle compared with the inner bearing, which, as the main factor, may cause the Z type bearing to overload and to fail. In this sense, the investigated Z type bearings are unfit to apply to situations with heavy load, high speed, or high precision.

  16. A single double-strand break system reveals repair dynamics and mechanisms in heterochromatin and euchromatin

    PubMed Central

    Janssen, Aniek; Breuer, Gregory A.; Brinkman, Eva K.; van der Meulen, Annelot I.; Borden, Sean V.; van Steensel, Bas; Bindra, Ranjit S.; LaRocque, Jeannine R.; Karpen, Gary H.

    2016-01-01

    Repair of DNA double-strand breaks (DSBs) must be properly orchestrated in diverse chromatin regions to maintain genome stability. The choice between two main DSB repair pathways, nonhomologous end-joining (NHEJ) and homologous recombination (HR), is regulated by the cell cycle as well as chromatin context. Pericentromeric heterochromatin forms a distinct nuclear domain that is enriched for repetitive DNA sequences that pose significant challenges for genome stability. Heterochromatic DSBs display specialized temporal and spatial dynamics that differ from euchromatic DSBs. Although HR is thought to be the main pathway used to repair heterochromatic DSBs, direct tests of this hypothesis are lacking. Here, we developed an in vivo single DSB system for both heterochromatic and euchromatic loci in Drosophila melanogaster. Live imaging of single DSBs in larval imaginal discs recapitulates the spatio–temporal dynamics observed for irradiation (IR)-induced breaks in cell culture. Importantly, live imaging and sequence analysis of repair products reveal that DSBs in euchromatin and heterochromatin are repaired with similar kinetics, employ both NHEJ and HR, and can use homologous chromosomes as an HR template. This direct analysis reveals important insights into heterochromatin DSB repair in animal tissues and provides a foundation for further explorations of repair mechanisms in different chromatin domains. PMID:27474442

  17. Methotrexatum intercalated layered double hydroxides: statistical design, mechanism explore and bioassay study.

    PubMed

    Wang, Xiao-Feng; Liu, Su-Qing; Li, Shu-Ping

    2015-04-01

    A series of methotrexatum intercalated layered double hydroxide (MTX/LDH for short) hybrids have been synthesized by a mechanochemical-hydrothermal method, the statistical experiments are planned and conducted to find out the critical factor influencing the physicochemical properties. Four variables, i.e., addition of NaOH solution, grinding duration, hydrothermal temperature and time, are chosen to play as the examined factors in the orthogonal design. Furthermore, three respective levels, i.e., high, medium and low levels, are conducted in the design. The resulting hybrids are then characterized by X-ray diffraction (XRD) patterns, transmission electron microscope (TEM) graphs and Zeta potentials. XRD diffractions indicate that MTX anions have been successfully intercalated into LDH interlayers and the amount of NaOH solution can change the gallery height greatly. The information from TEM graphs and Zeta potentials state that the increase of alkali solution gives rise to regular morphology and the increase of Zeta potentials. As a result of the statistical analysis, addition of alkali solution is the major factor affecting the morphology and drug-loading capacity. At last, the mechanism of particle growth is explored emphatically, and the anticancer efficacy of some MTX/LDH hybrids is estimated by MTT assay on A549 cells as well.

  18. Hydroxy double salts loaded with bioactive ions: Synthesis, intercalation mechanisms, and functional performance

    SciTech Connect

    Kaassis, Abdessamad Y.A.; Xu, Si-Min; Guan, Shanyue; Evans, David G.; Wei, Min; Williams, Gareth R.

    2016-06-15

    The intercalation of the anions of diclofenac (Dic), naproxen (Nap), and valproic acid (Val) into three hydroxy double salts (HDSs) has been explored in this work. Experiments were performed with [Co{sub 1.2}Zn{sub 3.8}(OH){sub 8}](NO{sub 3}){sub 2}·2H{sub 2}O (CoZn-NO{sub 3}), [Ni{sub 2}Zn{sub 3}(OH){sub 8}](NO{sub 3}){sub 2}·2H{sub 2}O (NiZn-NO{sub 3}) and [Zn{sub 5}(OH){sub 8}](NO{sub 3}){sub 2}·2H{sub 2}O (Zn-NO{sub 3}). It proved possible to intercalate diclofenac and naproxen into all three HDSs. In contrast, Val could be intercalated into CoZn-NO{sub 3} but when it was reacted with Zn-NO{sub 3} the HDS structure was destroyed, and the product comprised ZnO. Successful intercalation was verified by X-ray diffraction, IR spectroscopy, and elemental microanalysis. Molecular dynamics simulations showed the Dic and Nap ions to arrange themselves in an “X” shape in the interlayer space, forming a bilayer. Val was found to adopt a position with its aliphatic groups parallel to the HDS layer, again in a bilayer. In situ time resolved X-ray diffraction experiments revealed that intercalation of Dic and Nap into CoZn-NO{sub 3} and Zn-NO{sub 3} is mechanistically complex, with a number of intermediate phases observed. In contrast, the intercalation of all three guests into NiZn-NO{sub 3} and of Val into CoZn-NO{sub 3} are simple one step reactions proceeding directly from the starting material to the product. The HDS-drug composites were found to have sustained release profiles. - Graphical abstract: Seven new drug intercalates of hydroxy double salts (HDSs) have been prepared and characterised. The intercalation mechanisms have been explored, and the drug release properties of the HDS/drug composites quantified. Display Omitted.

  19. Identification of shareholder ethics and responsibilities in online reverse auctions for construction projects.

    PubMed

    Hatipkarasulu, Yilmaz; Gill, James H

    2004-04-01

    The increasing number of companies providing internet services and auction tools helped popularize the online reverse auction trend for purchasing commodities and services in the last decade. As a result, a number of owners, both public and private, accepted the online reverse auctions as the bidding technique for their construction projects. Owners, while trying to minimize their costs for construction projects, are also required to address their ethical responsibilities to the shareholders. In the case of online reverse auctions for construction projects, the ethical issues involved in the bidding technique directly reflects on the owner's ethical and social responsibilities to their shareholders. The goal of this paper is to identify the shareholder ethics and responsibilities in online reverse auctions for construction projects by analyzing the ethical issues for the parties involved in the process. The identification of the ethical issues and responsibilities requires clear definition and understanding of professional ethics and the roles of the involved parties. In this paper, first, the concept of professional ethics and social responsibility is described in a general form. To illustrate the ethical issues and responsibilities, a sample case of bidding for a construction project using online reverse auction techniques is presented in which the shareholders were actively involved in questioning the ethical issues. The issues involved in the bidding process and their reflection on the shareholder responsibilities are described and analyzed for each stage of the process. A brief discussion of the overall process is also included to address the general ethical issues involved in online reverse auctions.

  20. Multiagent model and mean field theory of complex auction dynamics

    NASA Astrophysics Data System (ADS)

    Chen, Qinghua; Huang, Zi-Gang; Wang, Yougui; Lai, Ying-Cheng

    2015-09-01

    Recent years have witnessed a growing interest in analyzing a variety of socio-economic phenomena using methods from statistical and nonlinear physics. We study a class of complex systems arising from economics, the lowest unique bid auction (LUBA) systems, which is a recently emerged class of online auction game systems. Through analyzing large, empirical data sets of LUBA, we identify a general feature of the bid price distribution: an inverted J-shaped function with exponential decay in the large bid price region. To account for the distribution, we propose a multi-agent model in which each agent bids stochastically in the field of winner’s attractiveness, and develop a theoretical framework to obtain analytic solutions of the model based on mean field analysis. The theory produces bid-price distributions that are in excellent agreement with those from the real data. Our model and theory capture the essential features of human behaviors in the competitive environment as exemplified by LUBA, and may provide significant quantitative insights into complex socio-economic phenomena.

  1. Mechanisms of fast and stringent search in homologous pairing of double-stranded DNA.

    PubMed

    Bitran, Amir; Chiang, Wei-Yin; Levine, Erel; Prentiss, Mara

    2017-03-01

    Self-organization in the cell relies on the rapid and specific binding of molecules to their cognate targets. Correct bindings must be stable enough to promote the desired function even in the crowded and fluctuating cellular environment. In systems with many nearly matched targets, rapid and stringent formation of stable products is challenging. Mechanisms that overcome this challenge have been previously proposed, including separating the process into multiple stages; however, how particular in vivo systems overcome the challenge remains unclear. Here we consider a kinetic system, inspired by homology dependent pairing between double stranded DNA in bacteria. By considering a simplified tractable model, we identify different homology testing stages that naturally occur in the system. In particular, we first model dsDNA molecules as short rigid rods containing periodically spaced binding sites. The interaction begins when the centers of two rods collide at a random angle. For most collision angles, the interaction energy is weak because only a few binding sites near the collision point contribute significantly to the binding energy. We show that most incorrect pairings are rapidly rejected at this stage. In rare cases, the two rods enter a second stage by rotating into parallel alignment. While rotation increases the stability of matched and nearly matched pairings, subsequent rotational fluctuations reduce kinetic trapping. Finally, in vivo chromosome are much longer than the persistence length of dsDNA, so we extended the model to include multiple parallel collisions between long dsDNA molecules, and find that those additional interactions can greatly accelerate the searching.

  2. Mechanisms of fast and stringent search in homologous pairing of double-stranded DNA

    PubMed Central

    Chiang, Wei-Yin; Prentiss, Mara

    2017-01-01

    Self-organization in the cell relies on the rapid and specific binding of molecules to their cognate targets. Correct bindings must be stable enough to promote the desired function even in the crowded and fluctuating cellular environment. In systems with many nearly matched targets, rapid and stringent formation of stable products is challenging. Mechanisms that overcome this challenge have been previously proposed, including separating the process into multiple stages; however, how particular in vivo systems overcome the challenge remains unclear. Here we consider a kinetic system, inspired by homology dependent pairing between double stranded DNA in bacteria. By considering a simplified tractable model, we identify different homology testing stages that naturally occur in the system. In particular, we first model dsDNA molecules as short rigid rods containing periodically spaced binding sites. The interaction begins when the centers of two rods collide at a random angle. For most collision angles, the interaction energy is weak because only a few binding sites near the collision point contribute significantly to the binding energy. We show that most incorrect pairings are rapidly rejected at this stage. In rare cases, the two rods enter a second stage by rotating into parallel alignment. While rotation increases the stability of matched and nearly matched pairings, subsequent rotational fluctuations reduce kinetic trapping. Finally, in vivo chromosome are much longer than the persistence length of dsDNA, so we extended the model to include multiple parallel collisions between long dsDNA molecules, and find that those additional interactions can greatly accelerate the searching. PMID:28257444

  3. Double-inversion mechanisms of the X⁻ + CH₃Y [X,Y = F, Cl, Br, I] SN2 reactions.

    PubMed

    Szabó, István; Czakó, Gábor

    2015-03-26

    The double-inversion and front-side attack transition states as well as the proton-abstraction channels of the X(-) + CH3Y [X,Y = F, Cl, Br, I] reactions are characterized by the explicitly correlated CCSD(T)-F12b/aug-cc-pVTZ(-PP) level of theory using small-core relativistic effective core potentials and the corresponding aug-cc-pVTZ-PP bases for Br and I. In the X = F case the double-inversion classical(adiabatic) barrier heights are 28.7(25.6), 15.8(13.4), 13.2(11.0), and 8.6(6.6) kcal mol(-1) for Y = F, Cl, Br, and I, respectively, whereas the barrier heights are in the 40-90 kcal mol(-1) range for the other 12 reactions. The abstraction channels are always above the double-inversion saddle points. For X = F, the front-side attack classical(adiabatic) barrier heights, 45.8(44.8), 31.0(30.3), 24.7(24.2), and 19.5(19.3) kcal mol(-1) for Y = F, Cl, Br, and I, respectively, are higher than the corresponding double-inversion ones, whereas for the other systems the front-side attack saddle points are in the 35-70 kcal mol(-1) range. The double-inversion transition states have XH···CH2Y(-) structures with Cs point-group symmetry, and the front-side attack saddle points have either Cs (X = F or X = Y) or C1 symmetry with XCY angles in the 78-88° range. On the basis of the previous reaction dynamics simulations and the minimum energy path computations along the inversion coordinate of selected XH···CH2Y(-) systems, we suggest that the double inversion may be a general mechanism for SN2 reactions.

  4. Bid distribution derived from consistent mixed strategy in lowest unique bid auction

    NASA Astrophysics Data System (ADS)

    Zhao, Yinan; Chen, Qinghua; Wang, Yougui

    2014-12-01

    The Lowest Unique Bid Auction (LUBA) booms recently through the Internet. A typical distribution pattern of bid price in this reverse auction has been found and needs to be interpreted. The distribution curve is a decreasing one whose slope has a close relationship with the number of agents participating in the auction. To explain this stylized fact, we develop a model assuming that agents prefer to bid on the price at which the probability of winning is higher. The bid distributions of actual auctions with the number of agents less than 200 can be fitted very well using the parameters for the value of items and the number of bids. When this number becomes larger, however, a deviation occurs between prediction and empirical data, which can be adjusted by introducing cognitive illusion of the bid number.

  5. 31 CFR 356.11 - How are bids submitted in an auction?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... participating in our auctions. (3) In contingency situations, such as a power outage, we may accept bids by a... Identification Number. (4) In contingency situations, such as a power outage, we may accept bids by other...

  6. Understanding overbidding: using the neural circuitry of reward to design economic auctions.

    PubMed

    Delgado, Mauricio R; Schotter, Andrew; Ozbay, Erkut Y; Phelps, Elizabeth A

    2008-09-26

    We take advantage of our knowledge of the neural circuitry of reward to investigate a puzzling economic phenomenon: Why do people overbid in auctions? Using functional magnetic resonance imaging (fMRI), we observed that the social competition inherent in an auction results in a more pronounced blood oxygen level-dependent (BOLD) response to loss in the striatum, with greater overbidding correlated with the magnitude of this response. Leveraging these neuroimaging results, we design a behavioral experiment that demonstrates that framing an experimental auction to emphasize loss increases overbidding. These results highlight a role for the contemplation of loss in understanding the tendency to bid "too high." Current economic theories suggest overbidding may result from either "joy of winning" or risk aversion. By combining neuroeconomic and behavioral economic techniques, we find that another factor, namely loss contemplation in a social context, may mediate overbidding in auctions.

  7. Fault structure and mechanics of the Hayward Fault, California from double-difference earthquake locations

    USGS Publications Warehouse

    Waldhauser, F.; Ellsworth, W.L.

    2002-01-01

    The relationship between small-magnitude seismicity and large-scale crustal faulting along the Hayward Fault, California, is investigated using a double-difference (DD) earthquake location algorithm. We used the DD method to determine high-resolution hypocenter locations of the seismicity that occurred between 1967 and 1998. The DD technique incorporates catalog travel time data and relative P and S wave arrival time measurements from waveform cross correlation to solve for the hypocentral separation between events. The relocated seismicity reveals a narrow, near-vertical fault zone at most locations. This zone follows the Hayward Fault along its northern half and then diverges from it to the east near San Leandro, forming the Mission trend. The relocated seismicity is consistent with the idea that slip from the Calaveras Fault is transferred over the Mission trend onto the northern Hayward Fault. The Mission trend is not clearly associated with any mapped active fault as it continues to the south and joins the Calaveras Fault at Calaveras Reservoir. In some locations, discrete structures adjacent to the main trace are seen, features that were previously hidden in the uncertainty of the network locations. The fine structure of the seismicity suggest that the fault surface on the northern Hayward Fault is curved or that the events occur on several substructures. Near San Leandro, where the more westerly striking trend of the Mission seismicity intersects with the surface trace of the (aseismic) southern Hayward Fault, the seismicity remains diffuse after relocation, with strong variation in focal mechanisms between adjacent events indicating a highly fractured zone of deformation. The seismicity is highly organized in space, especially on the northern Hayward Fault, where it forms horizontal, slip-parallel streaks of hypocenters of only a few tens of meters width, bounded by areas almost absent of seismic activity. During the interval from 1984 to 1998, when digital

  8. Synthetic aperture double exposure digital holographic interferometry for wide angle measurement and monitoring of mechanical displacements

    NASA Astrophysics Data System (ADS)

    Kujawinska, M.; Makowski, P.; Finke, G.; Zak, J.; Józwik, M.; Kozacki, T.

    2015-08-01

    A novel approach for wide angle registration and display of double exposure digital holograms of 3D objects under static or step-wise load is presented. The registration setup concept combines digital Fourier holography with synthetic aperture (SA) technique, which is equivalent to usage of a wide angle, spherically curved detector. The coherent object wavefields extracted from a pair of acquisitions collected in the synthetic aperture double exposure digital holographic interferometry scheme (SA DEDH) are utilized as the input for two different scenarios of investigation, which include (i) numerical determination of 2D phase difference fringes representing deformation of an object and (ii) physical displaying of a 3D image resulting from interference of two object (slightly different) wavefronts registered at the SA double exposure hologram. The capture and display processes are analyzed and implemented. The applicability of both numerical and experimental approach to SA DEDH for testing engineering objects is discussed.

  9. Physical Mechanisms and Scaling Laws of K-Shell Double Photoionization

    SciTech Connect

    Hoszowska, J.; Dousse, J.-Cl.; Berset, M.; Cao, W.; Fennane, K.; Kayser, Y.; Szlachetko, J.; Szlachetko, M.; Kheifets, A. K.; Bray, I.; Kavcic, M.

    2009-02-20

    We report on the photon energy dependence of the K-shell double photoionization (DPI) of Mg, Al, and Si. The DPI cross sections were derived from high-resolution measurements of x-ray spectra following the radiative decay of the K-shell double vacancy states. Our data evince the relative importance of the final-state electron-electron interaction to the DPI. By comparing the double-to-single K-shell photoionization cross-section ratios for neutral atoms with convergent close-coupling calculations for He-like ions, the effect of outer shell electrons on the K-shell DPI process is assessed. Universal scaling of the DPI cross sections with the effective nuclear charge for neutral atoms is revealed.

  10. Physical Mechanisms and Scaling Laws of K-Shell Double Photoionization

    NASA Astrophysics Data System (ADS)

    Hoszowska, J.; Kheifets, A. K.; Dousse, J.-Cl.; Berset, M.; Bray, I.; Cao, W.; Fennane, K.; Kayser, Y.; Kavčič, M.; Szlachetko, J.; Szlachetko, M.

    2009-02-01

    We report on the photon energy dependence of the K-shell double photoionization (DPI) of Mg, Al, and Si. The DPI cross sections were derived from high-resolution measurements of x-ray spectra following the radiative decay of the K-shell double vacancy states. Our data evince the relative importance of the final-state electron-electron interaction to the DPI. By comparing the double-to-single K-shell photoionization cross-section ratios for neutral atoms with convergent close-coupling calculations for He-like ions, the effect of outer shell electrons on the K-shell DPI process is assessed. Universal scaling of the DPI cross sections with the effective nuclear charge for neutral atoms is revealed.

  11. The Allocation of Runway Slots by Auction. Volume III. Theory and Technical Issues for Implementation.

    DTIC Science & Technology

    1980-04-15

    air polution , noise, landside traffic c.)ngestion and so on--dictate a different approach at l_ ast for some congested airports (notably Washington...approaches to slot auctions have not allowed for the inter- dependency of slot values to the air carriers--a single slot for a landing of an aircraft is...slot exchange. 17. Key Woeds II. Distrlbution Stmtome Slot, exchange, auction, trading, air Document is available to the public carriers, allocation

  12. Increasing the Effectiveness of Navy Retention Compensation by Evaluating Different Auction Compensation Formats

    DTIC Science & Technology

    2015-06-01

    EFFECTIVENESS OF NAVY RETENTION COMPENSATION BY EVALUATING DIFFERENT AUCTION COMPENSATION FORMATS by Terry W. Triplett Michael K. Winters...RETENTION COMPENSATION BY EVALUATING DIFFERENT AUCTION COMPENSATION FORMATS 5. FUNDING NUMBERS 6. AUTHOR(S) Terry W. Triplett and Michael K...The views expressed in this thesis are those of the author and do not reflect the official policy or position of the Department of Defense or the

  13. Argentine drilling equipment to go on auction block

    SciTech Connect

    Not Available

    1992-04-27

    Yacimientos Petroliferos Fiscales (YPF) is preparing to sell all state owned drilling rigs and related assets as part of a plan to privatize Argnetina's oil and gas industry. YPF expects to offer the equipment to private companies by summer in a sealed bid auction in Buenos Aires. More than 30 mostly late model U.S. and Romanian rigs rated to 1,800-7,000 m will be included in the sale. Drilling contracts covering all major Argentina exploration areas will be offered with many of the rigs being sold. This paper reports that the YPF sale will include well completion units, drill pipe and collars, large equipment yards, shops, and warehouses, and possibly the largest inventory of fishing tools in South America, says a company helping to organize the sale. YPF will set up a data room in Buenos Aires to provide information about drilling, conditions, rigs and equipment, and other assets.

  14. Combining auctions and performance-based payments in a forest enrichment field trial in Western Kenya.

    PubMed

    Khalumba, Mercelyne; Wünscher, Tobias; Wunder, Sven; Büdenbender, Mirjam; Holm-Müller, Karin

    2014-06-01

    Cost-effectiveness is an important aspect in the assessment of payments for environmental services (PES) initiatives. In participatory field trials with communities in Western Kenya, we combined procurement auctions for forest enrichment contracts with performance-based payments and compared the outcomes with a baseline scenario currently used by the Kenyan Forest Service. Procurement auctions were the most cost-effective. The competitive nature of the auction reduced contracting expenses (provision costs), and the result-oriented payments provided additional incentives to care for the planted seedlings, resulting in their improved survival rates (service quantity). These gains clearly exceeded increases in transaction costs associated with conducting an auction. The number of income-poor auction participants and winners was disproportionately high and local institutional buy-in was remarkably strong. Our participatory approach may, however, require adaptations when conducted at a larger scale. Although the number of contracts we monitored was limited and prohibited the use of statistical tests, our study is one of the first to reveal the benefits of using auctions for PES in developing countries.

  15. [Research on the mechanical properties of bone scaffold reinforced by magnesium alloy/bioceramics composite with stereolithography double channels].

    PubMed

    Li, Changhai; Lian, Qin; Zhuang, Pei; Wang, Junzhong; Li, Dichen

    2015-02-01

    Focusing on the poor mechanical strength of porous bioceramics bone scaffold, and taking into account of the good mechanical properties of biodegradable magnesium alloy, we proposed a novel method to fabricate magnesium alloy/bioceramics composite bone scaffold with stereolithography double channels. Firstly, a scaffold structure without mutually connected double channels was designed. Then, an optimized bioceramics scaffold was fabricated according to stereolithography and gel-casing. Molten AZ31 magnesium alloy was perfused into the secondary channel of scaffold by low-pressure casting, and magnesium alloy/bioceramics composite bone scaffold was obtained when magnesium alloy was solidified. The compression test showed that the strength of bioceramics scaffold with only one channel and without magnesium alloy was (9.76 ± 0.64) MPa, while the strength of magnesium alloy/bioceramics composite scaffold with double channels was (17.25 ± 0.88) MPa. It can be concluded that the magnesium alloy/bioceramics composite is obviously able to improve the scaffold strength.

  16. RecBCD is required to complete chromosomal replication: Implications for double-strand break frequencies and repair mechanisms.

    PubMed

    Courcelle, Justin; Wendel, Brian M; Livingstone, Dena D; Courcelle, Charmain T

    2015-08-01

    Several aspects of the mechanism of homologous double-strand break repair remain unclear. Although intensive efforts have focused on how recombination reactions initiate, far less is known about the molecular events that follow. Based upon biochemical studies, current models propose that RecBCD processes double-strand ends and loads RecA to initiate recombinational repair. However, recent studies have shown that RecBCD plays a critical role in completing replication events on the chromosome through a mechanism that does not involve RecA or recombination. Here, we examine several studies, both early and recent, that suggest RecBCD also operates late in the recombination process - after initiation, strand invasion, and crossover resolution have occurred. Similar to its role in completing replication, we propose a model in which RecBCD is required to resect and resolve the DNA synthesis associated with homologous recombination at the point where the missing sequences on the broken molecule have been restored. We explain how the impaired ability to complete chromosome replication in recBC and recD mutants is likely to account for the loss of viability and genome instability in these mutants, and conclude that spontaneous double-strand breaks and replication fork collapse occur far less frequently than previously speculated.

  17. Green Auctions and Reduction of Information Rents in Payments for Environmental Services: An Experimental Investigation in Sunan County, Northwestern China

    PubMed Central

    Deng, Xiaohong; Xu, Zhongmin

    2015-01-01

    Reducing information rents is an important task for government agencies wishing to purchase maximal environmental services with limited budgets. This paper reports on several green auction options for reducing information rents and improving the performance of the “Grain for Green” Payments for environmental services (PES) program implemented in northwestern China. In r experimental auctions and investigations, door-to-door interviews were conducted and bidding envelopes and survey questionnaires were used to determine the offers and the foregone profits of the participants. Three scenarios are analyzed in this paper: a uniform price auction, a discriminatory price auction, and an opportunity-cost system. The results show that compared to the uniform price auction system, the other auction systems can increase the cost-effectiveness of conservation contracting. Competitive bidding can reveal true opportunity costs and can reduce information rents extracted from the government by farmers using private information. The demographics and average bids of these auction types were also analyzed. “Perfect information” in the opportunity-cost offer system has the best performance but is very hard to implement in reality. The results of this research show that the auction is a valuable tool for purchasing conservation contracts in northwestern China, but that in the future, the performance of these auctions should be studied with relaxed model assumptions. PMID:25793263

  18. Green auctions and reduction of information rents in payments for environmental services: an experimental investigation in Sunan County, northwestern China.

    PubMed

    Deng, Xiaohong; Xu, Zhongmin

    2015-01-01

    Reducing information rents is an important task for government agencies wishing to purchase maximal environmental services with limited budgets. This paper reports on several green auction options for reducing information rents and improving the performance of the "Grain for Green" Payments for environmental services (PES) program implemented in northwestern China. In r experimental auctions and investigations, door-to-door interviews were conducted and bidding envelopes and survey questionnaires were used to determine the offers and the foregone profits of the participants. Three scenarios are analyzed in this paper: a uniform price auction, a discriminatory price auction, and an opportunity-cost system. The results show that compared to the uniform price auction system, the other auction systems can increase the cost-effectiveness of conservation contracting. Competitive bidding can reveal true opportunity costs and can reduce information rents extracted from the government by farmers using private information. The demographics and average bids of these auction types were also analyzed. "Perfect information" in the opportunity-cost offer system has the best performance but is very hard to implement in reality. The results of this research show that the auction is a valuable tool for purchasing conservation contracts in northwestern China, but that in the future, the performance of these auctions should be studied with relaxed model assumptions.

  19. The detection system of local mechanical strength of material based on double-hole micro-shear

    NASA Astrophysics Data System (ADS)

    Ding, Shoucheng; Li, Wenhui; Yang, Shizhou; Yuan, Guici

    2008-12-01

    The paper introduces a detection system of local mechanical strength of material. The principle of the system is based on the double-hole micro-shear test method. The core of detection system is MSP430F149 SCM. The working principle of the system is that the shear tool is driven by the stepper motor; the data is gathered by the load sensor and the displacement sensor; after it is processed by A/D converter of MSP430F149 SCM, we can gain the load and the displacement curve and get the maximum point of yield strength; according to the load value, the system determines the material mechanical intensity; Thus, a real-time detection system is set up. Experimental results show that detecting system based on double-hole micro-shear is fast, easy, accurate and intuitive to detect mechanical strength of the local material. So it can be widely applied to detect the local mechanical strength of kinds of mining and load bearing equipment via setting reasonable load value, which can avoid the accident of overload or super strength effectively.

  20. Formating double layer mechanism by electric charged particle stream in plasma

    NASA Astrophysics Data System (ADS)

    Shan-jun, Ma; Qian-li, Yang; Xiao-qing, Li

    1998-08-01

    In this paper, two-fluid equations have been solved after having considered magnetic field generated by charged particle stream. Finally, the distribution of electric field Ez(z, r) and its growth rate γ in plasma have been obtained. From the expression of Ez(z, r) it can be known that the double layer has been formed. With the increase of disturbance γ will be larger, and finally this will result in the interruption of electric current and occurrence of burst.

  1. Fabrication of double-aperture hololens imaging system: application to mechanics

    NASA Astrophysics Data System (ADS)

    Yadav, H. L.; Kumari, Neelam; Bhushan, Ravi; Mallick, Anshuman; Gupta, B. N.

    2004-06-01

    Duffy suggested the use of double-aperture imaging system for the measurement of in-plane displacement component. In this arrangement, twin apertures are placed symmetrically over the imaging lens. This imaging system is used in speckle metrology to measure component of displacement parallel to the line joining the two apertures. The imaging lens used in such configuration need not be diffraction limited over the entire lens aperture, but only over the two small areas encompassed by the two apertures. In present work, compact holographic lenses have been used to generate the two apertures of Duffy's double-aperture interferometer. This imaging system has been used in speckle metrology to measure crack mouth opening displacement (CMOD) in an aluminium beam specimen having central edge crack subjected to three point bending. Experimental results are in good agreement with theoretical predictions. Present experimental investigation reveals that compact holographic lenses can be used advantageously to generate apertures of double-aperture speckle interferometer for its use in the measurement of in-plane displacement component.

  2. Determination of Constitutive Equation for Thermo-mechanical Processing of INCONEL 718 Through Double Multivariate Nonlinear Regression Analysis

    NASA Astrophysics Data System (ADS)

    Hussain, Mirza Zahid; Li, Fuguo; Wang, Jing; Yuan, Zhanwei; Li, Pan; Wu, Tao

    2015-07-01

    The present study comprises the determination of constitutive relationship for thermo-mechanical processing of INCONEL 718 through double multivariate nonlinear regression, a newly developed approach which not only considers the effect of strain, strain rate, and temperature on flow stress but also explains the interaction effect of these thermo-mechanical parameters on flow behavior of the alloy. Hot isothermal compression experiments were performed on Gleeble-3500 thermo-mechanical testing machine in the temperature range of 1153 to 1333 K within the strain rate range of 0.001 to 10 s-1. The deformation behavior of INCONEL 718 is analyzed and summarized by establishing the high temperature deformation constitutive equation. The calculated correlation coefficient ( R) and average absolute relative error ( AARE) underline the precision of proposed constitutive model.

  3. The unexpected mechanism of carbonyl hydrosilylation catalyzed by (Cp)(ArN[double bond, length as m-dash])Mo(H)(PMe(3)).

    PubMed

    Shirobokov, Oleg G; Gorelsky, Serge I; Simionescu, Razvan; Kuzmina, Lyudmila G; Nikonov, Georgii I

    2010-11-07

    Complex (Cp)(ArN[double bond, length as m-dash])Mo(H)(PMe(3)) (2, Ar = 2,6-diisopropylphenyl) catalyzes the hydrosilylation of carbonyls by an unexpected associative mechanism. Complex 2 also reacts with PhSiH(3) by a σ-bond metathesis mechanism to give the silyl derivative (Cp)(ArN[double bond, length as m-dash])Mo(SiH(2)Ph)(PMe(3)).

  4. Elucidating double aggregation mechanisms in the morphology optimization of diketopyrrolopyrrole-based narrow bandgap polymer solar cells.

    PubMed

    Gao, Jing; Chen, Wei; Dou, Letian; Chen, Chun-Chao; Chang, Wei-Hsuan; Liu, Yongsheng; Li, Gang; Yang, Yang

    2014-05-21

    The power conversion efficiency (PCE) of a DPP-based polymer solar cell is significantly improved by using DIO or DCB as processing additives. The discovery that DCB outperforms DIO with a significantly wider solvent mixture operation window suggests different optimization mechanisms. Although both solvent mixture systems involve double aggregation processes, including a similar solution-to-film aggregation, however, two distinct solution-stage aggregations are observed: relatively amorphous polymer aggregates form in the CF-DIO solution, while more crystalline polymer aggregates form in CF-DCB solution.

  5. Double proton transfer mechanism in the adenine-uracil base pair and spontaneous mutation in RNA duplex

    NASA Astrophysics Data System (ADS)

    Cerón-Carrasco, José P.; Requena, Alberto; Perpète, Eric A.; Michaux, Catherine; Jacquemin, Denis

    2009-12-01

    We study the mechanism of double proton transfer (DPT) in the adenine-uracil (AU) base pair, both in gas phase and under the influence of surrounding water molecules. According to our ab initio calculations, no stable proton transfer product exists in gas phase, while in solution, the DPT process may occur only through the catalysis of water molecules. Nevertheless, a thermodynamic analysis confirms that AU does not contribute to spontaneous mutation in RNA duplex, and thus guanine-cytosine (GC) would be the only base pair contributing to spontaneous mutation.

  6. A fully coupled Thermo-Hydro-Mechanical Double Porosity Formulation for Modeling Multiphysics Problems in Geological Media

    NASA Astrophysics Data System (ADS)

    Sanchez, M. J.; Gens, A.; Jarecki, Z.; Olivella, S.

    2012-12-01

    This work presents a coupled Thermo-Hydro-Mechanical (THM) formulation developed to handle multiphysic problems in porous media with two dominant void levels. The proposed framework assumes the presence of two porous media linked through a mass transfer term between them. In many cases, the use of a double porosity formulation is more realistic because it is possible to take explicitly into account the different physical phenomena that take place in each void level, and also their mutual interactions. The formulation is especially suitable for cases in which the material exhibits a strong coupling between the mechanical and the hydraulic problem in both media. The problem is approached using a multi-phase, multi-species formulation that expresses mathematically the main coupled thermo-hydro-mechanical phenomena in terms of: balance equations, constitutive equations and equilibrium restrictions. In its more general form, the proposed approach allows the consideration of multiphase flow in the two pore levels coupled with the mechanical problem. The formulation presented is quite open and general, and able to incorporate different constitutive laws for each basic structural level considered; for the mechanical, hydraulic and thermal problems. The double structure formulation has been implemented in the finite element program CODE_BRIGHT and it has been used to analyze a variety of engineering problems associated with the design of radioactive waste disposal in deep geological media and petroleum engineering problems. This work presents two case studies; one is related to oil production in a heterogeneous reservoir, and the other case focuses on the analysis of a repository for nuclear waste in a clayed formation. Both cases show the potential of the proposed formation to tackle coupled multiphysics problems in porous media.

  7. Probable new type of reaction mechanism: Double. cap alpha. direct transfer process

    SciTech Connect

    Xu Shu-wei; Wu Guo-hua; Miao Rong-zhi; Han Fei

    1983-10-01

    It is assumed that /sup 8/Be consists of two ..cap alpha.. particles which are close to each other in configuration space. A spectroscopic density of /sup 8/Be cluster in the residue nuclei is then obtained, which is proportional to the square of the preformation probability of ..cap alpha.. particle at nuclear surface. Using the improved method of parametrization of EFR-DWBA overlap integral,/sup 1//sup en-dash//sup 2/ we calculate the double differential energy spectra and angular distributions of ..cap alpha.. particles for the reactions /sup 209/Bi (/sup 12/C, ..cap alpha..) /sup 217/Fr and extract the preformation probability of ..cap alpha.. particle at the surface of /sup 217/Fr nuclei from fitting the experimental data. The agreement within the range of calculation error between the preformation probabilities extracted from transfer reactions and ..cap alpha.. decay suggests that the reaction /sup 209/Bi(/sup 12/C, ..cap alpha..) /sup 217/Fr may be explained as a double ..cap alpha.. direct transfer process.

  8. Competitive bidding for health insurance contracts: lessons from the online HMO auctions.

    PubMed

    Gupta, Alok; Parente, Stephen T; Sanyal, Pallab

    2012-12-01

    Healthcare is an important social and economic component of modern society, and the effective use of information technology in this industry is critical to its success. As health insurance premiums continue to rise, competitive bidding may be useful in generating stronger price competition and lower premium costs for employers and possibly, government agencies. In this paper, we assess an endeavor by several Fortune 500 companies to reduce healthcare procurement costs for their employees by having HMOs compete in open electronic auctions. Although the auctions were successful in generating significant cost savings for the companies in the first year, i.e., 1999, they failed to replicate the success and were eventually discontinued after two more years. Over the past decade since the failed auction experiment, effective utilization of information technologies have led to significant advances in the design of complex electronic markets. Using this knowledge, and data from the auctions, we point out several shortcomings of the auction design that, we believe, led to the discontinuation of the market after three years. Based on our analysis, we propose several actionable recommendations that policy makers can use to design a sustainable electronic market for procuring health insurance.

  9. Electronic Reverse Auctions: Integrating an E-Sourcing Tool into a Sales and Purchasing Cross-Course Negotiation Project

    ERIC Educational Resources Information Center

    Williams, Jacqueline A.; Dobie, Kathryn

    2011-01-01

    Electronic reverse auctions are increasingly being used by firms to improve firm financial and operational performance. The described teaching innovation serves as a model for introducing electronic reverse auctions as a central element in a comprehensive negotiation exercise involving sales management and purchasing management students. Results…

  10. 78 FR 68839 - Tribal Mobility Fund Phase I Auction Rescheduled for February 25, 2014; Notice of Changes to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-15

    ... COMMISSION Tribal Mobility Fund Phase I Auction Rescheduled for February 25, 2014; Notice of Changes to... single-round reverse auction that will award up to $50 million in one-time Tribal Mobility Fund Phase I... Rescheduling Public Notice, the Bureaus adopt schedule changes intended to give potential bidders...

  11. 7 CFR 29.75b - Display of baled flue-cured tobacco on auction warehouse floors in designated markets.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... warehouse floors in designated markets. 29.75b Section 29.75b Agriculture Regulations of the Department of... Inspection § 29.75b Display of baled flue-cured tobacco on auction warehouse floors in designated markets. Each lot of baled flue-cured tobacco displayed for sale on auction warehouse floors shall have...

  12. 75 FR 61752 - Auction of FM Broadcast Construction Permits Scheduled for March 29, 2011; Comment Sought on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-06

    ... broadcast facility, and recent broadcast transaction data. The proposed minimum opening bid amount for each... Competitive Bidding Procedures for Auction 91 AGENCY: Federal Communications Commission. ACTION: Notice... March 29, 2011 (Auction 91). This document also seeks comment on competitive bidding procedures...

  13. 7 CFR 29.75b - Display of baled flue-cured tobacco on auction warehouse floors in designated markets.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Display of baled flue-cured tobacco on auction... AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Regulations Mandatory Inspection § 29.75b Display of baled flue-cured tobacco on auction warehouse floors in designated...

  14. 7 CFR 29.75b - Display of baled flue-cured tobacco on auction warehouse floors in designated markets.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Display of baled flue-cured tobacco on auction... AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Regulations Mandatory Inspection § 29.75b Display of baled flue-cured tobacco on auction warehouse floors in designated...

  15. Unconventional Tough Double-Network Hydrogels with Rapid Mechanical Recovery, Self-Healing, and Self-Gluing Properties.

    PubMed

    Jia, Haiyan; Huang, Zhangjun; Fei, Zhaofu; Dyson, Paul J; Zheng, Zhen; Wang, Xinling

    2016-11-16

    Hydrogels are polymeric materials that have a relatively high capacity for holding water. Recently, a double network (DN) technique was developed to fabricate hydrogels with a toughness comparable to rubber. The mechanical properties of DN hydrogels may be attributed to the brittle sacrificial bonding network of one hydrogel, facilitating stress dispersion, combined with ductile polymer chains of a second hydrogel. Herein, we report a novel class of tunable DN hydrogels composed of a polyurethane hydrogel and a stronger, dipole-dipole and H-bonding interaction reinforced (DHIR) hydrogel. Compared to conventional DN hydrogels, these materials show remarkable improvements in mechanical recovery, modulus, and yielding, with excellent self-healing and self-gluing properties. In addition, the new DN hydrogels exhibit excellent tensile and compression strengths and possess shape-memory properties, which make them promising for applications in engineering, biomedicine, and other domains where load bearing is required.

  16. Mechanical coupled vibrations in an individual double-walled carbon nanotube

    NASA Astrophysics Data System (ADS)

    Boutahir, Mourad; Rahmani, Abdelhai; Chadli, Hassan; Rahmani, Abdelali

    2016-05-01

    In this paper we calculate the Raman spectra of different double-walled carbon nanotubes (DWCNTs) by using the spectral moments method. Using a convenient Lennard-Jones expression of the van der Waals intermolecular interaction between the inner and outer tubes, the optimized structures of DWCNT are derived. We found that the C-C bond length in DWCNT is depending on the metallic (M) or semiconducting (Sc) character of the inner and outer nanotubes. We show that the radial breathing-like modes (RBLM) of DWCNT are characterized by concerted inner and outer wall motions. Comparison with Raman spectra measurements is given. Contribution to the topical issue "Materials for Energy Harvesting, Conversion and Storage (ICOME 2015) - Elected submissions", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

  17. An investigation into the mechanics of double-sided incremental forming using finite element methods

    NASA Astrophysics Data System (ADS)

    Moser, Newell; Zhang, Zixuan; Ren, Huaqing; Ehmann, Kornel; Cao, Jian

    2016-10-01

    Double-Sided Incremental Forming (DSIF) is a developing sheet metal manufacturing process that has gained a lot of attention in recent years due to its inherent flexibility, low-overhead cost, and die-less nature. However, it can be challenging to define the tool gap so as to achieve a desired pressure through the sheet thickness since one must first predict sheet thinning. In this investigation, a novel part design is proposed which varies in-plane curvature as a function of depth. A finite element model for DSIF is developed and the strain histories in various regions are extracted. It was concluded that if the supporting tool loses contact with the sheet, localized necking can occur prior to part failure. Additionally, part geometry can have significant effects on the tool contact area which, consequently, affects the evolution of strain.

  18. Methotrexate intercalated layered double hydroxides with the mediation of surfactants: Mechanism exploration and bioassay study.

    PubMed

    Dai, Chao-Fan; Tian, De-Ying; Li, Shu-Ping; Li, Xiao-Dong

    2015-12-01

    Methotrexatum intercalated layered double hydroxides (MTX/LDHs) hybrids were synthesized by the co-precipitation method and three kinds of nonionic surfactants with different hydrocarbon chain lengths were used. The resulting hybrids were then characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM). XRD and FTIR investigations manifest the successful intercalation of MTX anions into the interlayer of LDHs. TEM graphs indicate that the morphology of the hybrids changes with the variation of the chain length of the surfactants, i.e., the particles synthesized using polyethylene glycol (PEG-7) present regular disc morphology with good monodispersity, while samples with the mediation of alkyl polyglycoside (APG-14) are heavily aggregated and samples with the addition of polyvinylpyrrolidone (PVP-10) exhibit irregular branches. Furthermore, the release and bioassay experiments show that monodisperse MTX/LDHs present good controlled-release and are more efficient in the suppression of the tumor cells.

  19. Mechanisms of double-strand break repair in somatic mammalian cells

    PubMed Central

    Hartlerode, Andrea J.; Scully, Ralph

    2010-01-01

    DNA chromosomal DSBs (double-strand breaks) are potentially hazardous DNA lesions, and their accurate repair is essential for the successful maintenance and propagation of genetic information. Two major pathways have evolved to repair DSBs: HR (homologous recombination) and NHEJ (non-homologous end-joining). Depending on the context in which the break is encountered, HR and NHEJ may either compete or co-operate to fix DSBs in eukaryotic cells. Defects in either pathway are strongly associated with human disease, including immunodeficiency and cancer predisposition. Here we review the current knowledge of how NHEJ and HR are controlled in somatic mammalian cells, and discuss the role of the chromatin context in regulating each pathway. We also review evidence for both co-operation and competition between the two pathways. PMID:19772495

  20. Physical contact influences how much people pay at celebrity auctions.

    PubMed

    Newman, George E; Bloom, Paul

    2014-03-11

    Contagion is a form of magical thinking in which people believe that a person's immaterial qualities or essence can be transferred to an object through physical contact. Here we investigate how a belief in contagion influences the sale of celebrity memorabilia. Using data from three high-profile estate auctions, we find that people's expectations about the amount of physical contact between the object and the celebrity positively predicts the final bids for items that belonged to well-liked individuals (e.g., John F. Kennedy) and negatively predicts final bids for items that belonged to disliked individuals (e.g., Bernard Madoff). A follow-up experiment further suggests that these effects are driven by contagion beliefs: when asked to bid on a sweater owned by a well-liked celebrity, participants report that they would pay substantially less if it was sterilized before they received it. However, sterilization increases the amount they would pay for a sweater owned by a disliked celebrity. These studies suggest that magical thinking may still have effects in contemporary Western societies and they provide some unique demonstrations of contagion effects on real-world purchase decisions.

  1. Water promoting electron hole transport between tyrosine and cysteine in proteins via a special mechanism: double proton coupled electron transfer.

    PubMed

    Chen, Xiaohua; Ma, Guangcai; Sun, Weichao; Dai, Hongjing; Xiao, Dong; Zhang, Yanfang; Qin, Xin; Liu, Yongjun; Bu, Yuxiang

    2014-03-26

    The proton/electron transfer reactions between cysteine residue (Cys) and tyrosinyl radical (Tyr(•)) are an important step for many enzyme-catalyzed processes. On the basis of the statistical analysis of protein data bank, we designed three representative models to explore the possible proton/electron transfer mechanisms from Cys to Tyr(•) in proteins. Our ab initio calculations on simplified models and quantum mechanical/molecular mechanical (QM/MM) calculations on real protein environment reveal that the direct electron transfer between Cys and Tyr(•) is difficult to occur, but an inserted water molecule can greatly promote the proton/electron transfer reactions by a double-proton-coupled electron transfer (dPCET) mechanism. The inserted H2O plays two assistant roles in these reactions. The first one is to bridge the side chains of Tyr(•) and Cys via two hydrogen bonds, which act as the proton pathway, and the other one is to enhance the electron overlap between the lone-pair orbital of sulfur atom and the π-orbital of phenol moiety and to function as electron transfer pathway. This water-mediated dPCET mechanism may offer great help to understand the detailed electron transfer processes between Tyr and Cys residues in proteins, such as the electron transfer from Cys439 to Tyr730(•) in the class I ribonucleotide reductase.

  2. A deployment mechanism for the double roll-out flexible solar array on the space telescope

    NASA Technical Reports Server (NTRS)

    Cawsey, T. R.

    1982-01-01

    A roll-out flexible array which provides more than 4 kW of power for the space telescope was developed. The Array is configured as two wings. The deployment mechanism for each wing is based on flight-proven FRUSA design. Modifications have been incorporated to accommodate an increase in size and mission requirements. The assembly and operation of the deployment mechanism are described together with environmental and functional tests results.

  3. Bidding process in online auctions and winning strategy: Rate equation approach.

    PubMed

    Yang, I; Kahng, B

    2006-06-01

    Online auctions have expanded rapidly over the last decade and have become a fascinating new type of business or commercial transaction in this digital era. Here we introduce a master equation for the bidding process that takes place in online auctions. We find that the number of distinct bidders who bid k times up to the tth bidding progresses, called the k-frequent bidder, seems to scale as n(k)(t) approximately tk(-2.4). The successfully transmitted bidding rate by the k-frequent bidder is likely to scale as q(k)(t) approximately k(-1.4), independent of t for large t. This theoretical prediction is close to empirical data. These results imply that bidding at the last moment is a rational and effective strategy to win in an eBay auction.

  4. Bidding process in online auctions and winning strategy: Rate equation approach

    NASA Astrophysics Data System (ADS)

    Yang, I.; Kahng, B.

    2006-06-01

    Online auctions have expanded rapidly over the last decade and have become a fascinating new type of business or commercial transaction in this digital era. Here we introduce a master equation for the bidding process that takes place in online auctions. We find that the number of distinct bidders who bid k times up to the t th bidding progresses, called the k -frequent bidder, seems to scale as nk(t)˜tk-2.4 . The successfully transmitted bidding rate by the k -frequent bidder is likely to scale as qk(t)˜k-1.4 , independent of t for large t . This theoretical prediction is close to empirical data. These results imply that bidding at the last moment is a rational and effective strategy to win in an eBay auction.

  5. How to estimate worth of minor value oil, gas producing properties at public auction

    SciTech Connect

    Randall, B.L. )

    1990-12-31

    The purpose of this paper is to evaluate the divestiture of minor value working and royalty interests (worth less than $20,000) in producing oil and gas properties through the transaction medium of no-minimum, English open outcry public auctions. Specifically, the paper seeks to answer the question, What can the seller expect to receive for his minor value properties at a public auction, knowing only how he values those properties to himself To answer this question, a mathematical model that predicts the seller's expected present worth (EPW) as a function of the seller's Securities and Exchange Commission-case book value (X{sub s}), and the winning bid value (X{sub B}) is derived from classical auction theory.

  6. Spiral of Hatred: Social Effects in Buyer-Seller Cross-Comments Left on Internet Auctions

    NASA Astrophysics Data System (ADS)

    Nielek, Radoslaw; Wawer, Aleksander; Wierzbicki, Adam

    An auction platform is a dynamic environment where a rich variety of social effects can be observed. Most of those effects remain unnoticed or even hidden to ordinary users. The in-depth studies of such effects should allow us to identify and understand the key factors influencing users’ behaviour. The material collected from the biggest Polish auction house has been analyzed. NLP algorithms were applied to extract sentiment-related content from collected comments. Emotional distance between negative, neutral and positive comments has been calculated. The obtained results confirm the existence of the spiral-of-hatred effect but also indicate that much more complex patterns of mutual relations between sellers and buyers exist. The last section contains a several suggestions which can prove useful to improve trustworthiness of users’ reports and security of an auction platform in general.

  7. Measuring electrical and mechanical properties of red blood cells with a double optical tweezers

    NASA Astrophysics Data System (ADS)

    Fontes, Adriana; Fernandes, Heloise P.; Barjas-Castro, Maria L.; de Thomaz, André A.; Pozzo, Liliana d. Y.; Barbosa, Luiz C.; Cesar, Carlos L.

    2006-08-01

    The fluid lipid bilayer viscoelastic membrane of red blood cells (RBC) contains antigen glycolproteins and proteins which can interact with antibodies to cause cell agglutination. This is the basis of most of the immunohematologic tests in blood banks and the identification of the antibodies against the erythrocyte antigens is of fundamental importance for transfusional routines. The negative charges of the RBCs creates a repulsive electric (zeta) potential between the cells and prevents their aggregation in the blood stream. The first counterions cloud strongly binded moving together with the RBC is called the compact layer. This report proposes the use of a double optical tweezers for a new procedure for measuring: (1) the apparent membrane viscosity, (2) the cell adhesion, (3) the zeta potential and (4) the compact layer's size of the charges formed around the cell in the electrolytic solution. To measure the membrane viscosity we trapped silica beads strongly attached to agglutinated RBCs and measured the force to slide one RBC over the other as a function of the relative velocity. The RBC adhesion was measured by slowly displacing two RBCs apart until the disagglutination happens. The compact layer's size was measured using the force on the silica bead attached to a single RBC in response to an applied voltage and the zeta potential was obtained by measuring the terminal velocity after releasing the RBC from the optical trap at the last applied voltage. We believe that the methodology here proposed can improve the methods of diagnosis in blood banks.

  8. Heat transfer augmentation in double pipe heat exchanger using mechanical turbulators

    NASA Astrophysics Data System (ADS)

    Kamboj, Kushal; Singh, Gurjeet; Sharma, Rohit; Panchal, Dilbagh; Hira, Jaspreet

    2016-05-01

    The work presented here focuses on heat transfer augmentation by means of divergent-convergent spring turbulator (the enhancement device). Aim of the present work is to find such an optimum pitch at which the augmentation in heat transfer is maximum and the amount of power consumption is minimum, so that an economic design can be created with maximum thermal efficiency. So, the concept of pitch variation is introduced, which is defined as the horizontal distance between two consecutive turbulators. It describes that, the lesser is the pitch the more number of turbulators that can be inserted in inner pipe of double pipe heat exchanger, hence more will be the friction factor. This physics increases convective ability of the heat transfer process from the surface of inner pipe. There is a certain limit to which a pitch can be decreased, lesser the pitch the more the pressure drop and friction factor and hence the more will be the pumping power requirement to maintain a desired mass flow rate of hot water. Analysis of thermal factors such as Nusselts number, friction factor, with different pitches of divergent convergent spring turbulators of circular cross-section 15, 10, and 5 cm at Reynolds's number ranging between 9000 < Re < 40,000 is done graphically.

  9. Heat transfer augmentation in double pipe heat exchanger using mechanical turbulators

    NASA Astrophysics Data System (ADS)

    Kamboj, Kushal; Singh, Gurjeet; Sharma, Rohit; Panchal, Dilbagh; Hira, Jaspreet

    2017-02-01

    The work presented here focuses on heat transfer augmentation by means of divergent-convergent spring turbulator (the enhancement device). Aim of the present work is to find such an optimum pitch at which the augmentation in heat transfer is maximum and the amount of power consumption is minimum, so that an economic design can be created with maximum thermal efficiency. So, the concept of pitch variation is introduced, which is defined as the horizontal distance between two consecutive turbulators. It describes that, the lesser is the pitch the more number of turbulators that can be inserted in inner pipe of double pipe heat exchanger, hence more will be the friction factor. This physics increases convective ability of the heat transfer process from the surface of inner pipe. There is a certain limit to which a pitch can be decreased, lesser the pitch the more the pressure drop and friction factor and hence the more will be the pumping power requirement to maintain a desired mass flow rate of hot water. Analysis of thermal factors such as Nusselts number, friction factor, with different pitches of divergent convergent spring turbulators of circular cross-section 15, 10, and 5 cm at Reynolds's number ranging between 9000 < Re < 40,000 is done graphically.

  10. Mechanical Properties of Double-Layer and Graded Composite Coatings of YSZ Obtained by Atmospheric Plasma Spraying

    NASA Astrophysics Data System (ADS)

    Carpio, Pablo; Rayón, Emilio; Salvador, María Dolores; Lusvarghi, Luca; Sánchez, Enrique

    2016-04-01

    Double-layer and graded composite coatings of yttria-stabilized zirconia were sprayed on metallic substrates by atmospheric plasma spray. The coating architecture was built up by combining two different feedstocks: one micro- and one nanostructured. Microstructural features and mechanical properties (hardness and elastic modulus) of the coatings were determined by FE-SEM microscopy and nanoindentation technique, respectively. Additional adherence and scratch tests were carried out in order to assess the failure mechanisms occurring between the layers comprising the composites. Microstructural inspection of the coatings confirms the two-zone microstructure. This bimodal microstructure which is exclusive of the layer obtained from the nanostructured feedstock negatively affects the mechanical properties of the whole composite. Nanoindentation tests suitably reproduce the evolution of mechanical properties through coatings thickness on the basis of the position and/or amount of nanostructured feedstock used in the depositing layer. Adhesion and scratch tests show the negative effect on the coating adhesion of layer obtained from the nanostructured feedstock when this layer is deposited on the bond coat. Thus, the poor integrity of this layer results in lower normal stresses required to delaminate the coating in the adhesion test as well as minor critical load registered by using the scratch test.

  11. Sorption mechanisms of arsenate on Mg-Fe layered double hydroxides: A combination of adsorption modeling and solid state analysis.

    PubMed

    Hudcová, Barbora; Veselská, Veronika; Filip, Jan; Číhalová, Sylva; Komárek, Michael

    2017-02-01

    Layered double hydroxides have been proposed as effective sorbents for As(V), but studies investigating adsorption mechanisms usually lack a comprehensive mechanistic/modeling approach. In this work, we propose coupling surface complexation modeling with various spectroscopic techniques. To this end, a series of batch experiments at different pH values were performed. Kinetic data were well fitted by a pseudo-second order kinetic model, and the equilibrium data were fitted by the Freundlich model. Moreover, the pH-dependent As(V) sorption data were satisfactorily fitted by a diffuse layer model, which described the formation of >SOAsO3H(-) monodentate and >(SO)2AsO2(-) bidentate inner-sphere complexes (">S" represents a crystallographically-bound group on the surface). Additionally, XPS analyses confirmed the adsorption mechanisms. The sorption mechanisms were affected by anion exchange, which was responsible for the formation of outer sphere complexes, as identified by XRD and FTIR analyses. Furthermore, a homogenous distribution of As(V) was determined by HR-TEM with elemental mapping. Using low-temperature Mössbauer spectroscopy on isotope (57)Fe, a slight shift of the hyperfine parameters towards higher values following As(V) sorption was measured, indicating a higher degree of structural disorder. In general, mechanistic adsorption modeling coupled with solid state analyses presents a powerful approach for investigating the adsorption mechanism of As(V) on Mg-Fe LDH or other sorbents.

  12. A new quantum sealed-bid auction protocol with secret order in post-confirmation

    NASA Astrophysics Data System (ADS)

    Wang, Jing-Tao; Chen, Xiu-Bo; Xu, Gang; Meng, Xiang-Hua; Yang, Yi-Xian

    2015-10-01

    A new security protocol for quantum sealed-bid auction is proposed to resist the collusion attack from some malicious bidders. The most significant feature of this protocol is that bidders prepare their particles with secret order in post-confirmation for encoding bids. In addition, a new theorem and its proof are given based on the theory of combinatorial mathematics, which can be used as evaluation criteria for the collusion attack. It is shown that the new protocol is immune to the collusion attack and meets the demand for a secure auction. Compared with those previous protocols, the security, efficiency and availability of the proposed protocol are largely improved.

  13. Practical Application of Principle-Agent and Auction Theory: A Contracting Guide

    DTIC Science & Technology

    2015-05-01

    Capt Will Griffin C1C Ryan Holler C1C Jimmy Manuel C1C Ryan McVay Practical Application of Principle-Agent and Auction Theory: A Contracting... Auction Theory: A Contracting Guide 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER...Statement of the Problem  The DOD holds an inferior position when bargaining with the private sector (known budget). This creates inefficiencies in

  14. Double-Negative Mechanical Metamaterials Displaying Simultaneous Negative Stiffness and Negative Poisson's Ratio Properties.

    PubMed

    Hewage, Trishan A M; Alderson, Kim L; Alderson, Andrew; Scarpa, Fabrizio

    2016-12-01

    A scalable mechanical metamaterial simultaneously displaying negative stiffness and negative Poisson's ratio responses is presented. Interlocking hexagonal subunit assemblies containing 3 alternative embedded negative stiffness (NS) element types display Poisson's ratio values of -1 and NS values over two orders of magnitude (-1.4 N mm(-1) to -160 N mm(-1) ), in good agreement with model predictions.

  15. Studying red blood cell agglutination by measuring electrical and mechanical properties with a double optical tweezers

    NASA Astrophysics Data System (ADS)

    Fontes, Adriana; Fernandes, Heloise P.; de Thomaz, André A.; Barbosa, Luiz C.; Barjas-Castro, Maria L.; Cesar, Carlos L.

    2007-07-01

    The red blood cell (RBC) viscoelastic membrane contains proteins and glycolproteins embedded in, or attached, to a fluid lipid bilayer and are negatively charged, which creates a repulsive electric (zeta) potential between the cells and prevents their aggregation in the blood stream. The basis of the immunohematologic tests is the interaction between antigens and antibodies that causes hemagglutination. The identification of antibodies and antigens is of fundamental importance for the transfusional routine. This agglutination is induced by decreasing the zeta-potential through the introduction of artificial potential substances. This report proposes the use of the optical tweezers to measure the membrane viscosity, the cell adhesion, the zeta-potential and the size of the double layer of charges (CLC) formed around the cell in an electrolytic solution. The adhesion was quantified by slowly displacing two RBCs apart until the disagglutination. The CLC was measured using the force on the bead attached to a single RBC in response to an applied voltage. The zeta-potential was obtained by measuring the terminal velocity after releasing the RBC from the optical trap at the last applied voltage. For the membrane viscosity experiment, we trapped a bead attached to RBCs and measured the force to slide one RBC over the other as a function of the relative velocity. After we tested the methodology, we performed measurements using antibody and potential substances. We observed that this experiment can provide information about cell agglutination that helps to improve the tests usually performed in blood banks. We also believe that this methodology can be applied for measurements of zeta-potentials in other kind of samples.

  16. Hydroxy double salts loaded with bioactive ions: Synthesis, intercalation mechanisms, and functional performance

    NASA Astrophysics Data System (ADS)

    Y. A. Kaassis, Abdessamad; Xu, Si-Min; Guan, Shanyue; Evans, David G.; Wei, Min; Williams, Gareth R.

    2016-06-01

    The intercalation of the anions of diclofenac (Dic), naproxen (Nap), and valproic acid (Val) into three hydroxy double salts (HDSs) has been explored in this work. Experiments were performed with [Co1.2Zn3.8(OH)8](NO3)2·2H2O (CoZn-NO3), [Ni2Zn3(OH)8](NO3)2·2H2O (NiZn-NO3) and [Zn5(OH)8](NO3)2·2H2O (Zn-NO3). It proved possible to intercalate diclofenac and naproxen into all three HDSs. In contrast, Val could be intercalated into CoZn-NO3 but when it was reacted with Zn-NO3 the HDS structure was destroyed, and the product comprised ZnO. Successful intercalation was verified by X-ray diffraction, IR spectroscopy, and elemental microanalysis. Molecular dynamics simulations showed the Dic and Nap ions to arrange themselves in an "X" shape in the interlayer space, forming a bilayer. Val was found to adopt a position with its aliphatic groups parallel to the HDS layer, again in a bilayer. In situ time resolved X-ray diffraction experiments revealed that intercalation of Dic and Nap into CoZn-NO3 and Zn-NO3 is mechanistically complex, with a number of intermediate phases observed. In contrast, the intercalation of all three guests into NiZn-NO3 and of Val into CoZn-NO3 are simple one step reactions proceeding directly from the starting material to the product. The HDS-drug composites were found to have sustained release profiles.

  17. Folding mechanism of a multiple independently-folding domain protein: double B domain of protein A.

    PubMed

    Arora, Pooja; Hammes, Gordon G; Oas, Terrence G

    2006-10-10

    The antibody binding properties of staphylococcal protein A (SpA) can be attributed to the presence of five highly homologous domains (E, D, A, B, and C). Although the folding of the B domain of protein A (BdpA) is well-characterized, the folding behavior of this domain in the context of full-length SpA in the cell remains unexplored. The sequence of the B domain is 89 and 91% identical to those of domains A and C, respectively. We have fused B domain sequences (BBdpA) as a close approximation of the A-B or B-C portion of SpA. Circular dichroism and fluorescence-detected denaturation curves of BBdpA are experimentally indistinguishable from those of BdpA. The rate constants for folding and unfolding from NMR line shape analysis for the single- and double-domain proteins are the same within experimental uncertainties (+/-20%). These results support the designation of SpA as a multiple independently-folding domain (MIFD) protein. We develop a mathematical model that describes the folding thermodynamics and kinetics of MIFD proteins. The model depicts MIFD protein folding and unfolding as a parallel network and explicitly calculates the flux through all parallel pathways. These fluxes are combined to give a complete description of the global thermodynamics and kinetics of the folding and unfolding of MIFD proteins. The global rates for complete folding and unfolding of a MIFD protein and those of the individual domains depend on the stability of the protein. We show that the global unfolding rate of a MIFD protein may be many orders of magnitude slower than that of the constituent domains.

  18. Double frequency absorption induced by Al-Si Schottky barrier potential and mechanism of two-photon response

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoting; Gao, Yanjun; Chen, Zhanguo; Jia, Gang; Liu, Yunlong; Liu, Xiuhuan; Zh, Yuhong

    2006-01-01

    By observing two-photon response and anisotropy of the light-induced voltage in Si-Al Schottky barrier potential of the Si MSM (Metal-Semiconductor-Metal) planar structure two-photon response optical detector. It is certified from the experimental and theoretical analysis that the built-in electric field generated by the Schottky barrier potential will induce the phenomena of optical rectification in Si photodiode. Thus, it is deduced that there must be double-frequency absorption (DFA) caused by phase-mismatch in the mechanism of two-photon response of Si photodiode. If the intensity of the built-in electric field is strong enough, the DFA will be the main feature of the two-photon response.

  19. Analysis on strength and stiffness of double-deck plates filter system of mechanical water treatment plant

    NASA Astrophysics Data System (ADS)

    Feng, De-zhen; Yu, Qi-qi

    2017-01-01

    Domestic water treatment is a very important technology field. Now, mechanical water treatment technology is getting wide use in production. In the process of life water treatment, filter process is a very important step. In this paper, the strength and deformation of double-deck plates filter system which includes upper filter plate, lower filter plate and reinforced ribs were analyzed with ANSYS and useful results were got. Through the analysis on strength and deformation, the paper found the advantages and disadvantages of production and design of filter systems. After analyzing and comparing the stresses and deformations of several different design schemes, the paper provided the optimized design plan of filter system which can satisfy the strength need and decrease the creep deformation of plastic filter plates.

  20. Mechanism of single- and double-sided inhibition of dual topology fluoride channels by synthetic monobodies.

    PubMed

    Turman, Daniel L; Stockbridge, Randy B

    2017-04-03

    The Fluc family of proteins comprises small, electrodiffusive fluoride channels, which prevent accumulation of toxic F(-) ions in microorganisms. Recent crystal structures have confirmed their unusual architecture, in which a pair of antiparallel subunits convenes to form a dimer with a twofold symmetry axis parallel to the plane of the membrane. These structures have also revealed the interactions between Fluc channels and several different fibronectin domain monobodies that inhibit Fluc-mediated F(-) currents; in all structures, each channel binds to two monobodies symmetrically, one on either side of the membrane. However, these structures do not reveal the mechanism of monobody inhibition. Moreover, the results appear to diverge from a recent electrophysiological study indicating that monobody binding is negatively cooperative; that is, a bound monobody on one side of a Fluc channel decreases the affinity of an oppositely bound monobody by ∼10-fold. In this study, we reconcile these observations by probing the mechanism of monobody binding and its negative cooperativity using electrophysiological experiments in planar lipid bilayers. Our results indicate that monobody inhibition occurs via a pore-blocking mechanism and that negative cooperativity arises from electrostatic repulsion between the oppositely bound monobodies. A single glutamate residue, on a loop of the monobody that extends into the channel interior, is responsible for negatively cooperative binding. This glutamate side chain also confers voltage dependence and sensitivity to the concentration of trans-F(-) ion to monobody binding. Neutralization by mutation to glutamine abolishes these electrostatic effects. Monobodies that are amenable to cocrystallization with Fluc channels lack an analogous negatively charged side chain and bind independently to opposite sides of the channel. Thus, this work reveals the source of voltage dependence and negative cooperativity of monobody binding to Fluc

  1. Study of Electrical Conduction Mechanism of Organic Double-Layer Diode Using Electric Field Induced Optical Second Harmonic Generation Measurement.

    PubMed

    Nishi, Shohei; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa

    2016-04-01

    By using electric field induced optical second harmonic generation (EFISHG) and current voltage (I-V) measurements, we studied the electrical transport mechanism of organic double-layer diodes with a structure of Au/N, N'-di-[(1-naphthyl)-N, N'-diphenyl]-(1,1'-biphenyl)-4,4'-diamine (a-NPD)/poly(methyl methacrylate) (PMMA)/indium zinc oxide (IZO). Here the α-NPD is a carrier transport layer and the PMMA is an electrical insulating layer. The current level was very low, but the I-V characteristics showed a rectifying behavior. The EFISHG measurement selectively and directly probed the electric field across the α-NPD layer, and showed that the electric field across the a-NPD layer is completely relaxed owing to the charge accumulation at the a-NPD/PMMA interface in the region V > 0, whereas the carrier accumulation was not significant in the region V < 0. On the basis of these experimental results, we proposed a model of the rectification. Further, by coupling the I-V characteristics with the EFISHG measurement, the I-V characteristics of the diodes were well converted into the current-electric field (I-E) characteristics of the α-NPD layer and the PMMA layer. The I-E characteristics suggested the Schottky-type conduction governs the carrier transport. We conclude that the I-V measurement coupled with the EFISHG measurement is very useful to study carrier transport mechanism of the organic double-layer diodes.

  2. Double torsion fracture mechanics testing of shales under chemically reactive conditions

    NASA Astrophysics Data System (ADS)

    Chen, X.; Callahan, O. A.; Holder, J. T.; Olson, J. E.; Eichhubl, P.

    2015-12-01

    Fracture properties of shales is vital for applications such as shale and tight gas development, and seal performance of carbon storage reservoirs. We analyze the fracture behavior from samples of Marcellus, Woodford, and Mancos shales using double-torsion (DT) load relaxation fracture tests. The DT test allows the determination of mode-I fracture toughness (KIC), subcritical crack growth index (SCI), and the stress-intensity factor vs crack velocity (K-V) curves. Samples are tested at ambient air and aqueous conditions with variable ionic concentrations of NaCl and CaCl2, and temperatures up to 70 to determine the effects of chemical/environmental conditions on fracture. Under ambient air condition, KIC determined from DT tests is 1.51±0.32, 0.85±0.25, 1.08±0.17 MPam1/2 for Marcellus, Woodford, and Mancos shales, respectively. Tests under water showed considerable change of KIC compared to ambient condition, with 10.6% increase for Marcellus, 36.5% decrease for Woodford, and 6.7% decrease for Mancos shales. SCI under ambient air condition is between 56 and 80 for the shales tested. The presence of water results in a significant reduction of the SCI from 70% to 85% compared to air condition. Tests under chemically reactive solutions are currently being performed with temperature control. K-V curves under ambient air conditions are linear with stable SCI throughout the load-relaxation period. However, tests conducted under water result in an initial cracking period with SCI values comparable to ambient air tests, which then gradually transition into stable but significantly lower SCI values of 10-20. The non-linear K-V curves reveal that crack propagation in shales is initially limited by the transport of chemical agents due to their low permeability. Only after the initial cracking do interactions at the crack tip lead to cracking controlled by faster stress corrosion reactions. The decrease of SCI in water indicates higher crack propagation velocity due to

  3. Nonsequential Double Ionization of Atoms in Strong Laser Field: Identifying the Mechanisms behind the Correlated-Electron Momentum Spectra

    NASA Astrophysics Data System (ADS)

    Ye, Difa; Fu, Libin; Liu, Jie

    Within the strong-field physics community, there has been increasing interest on nonsequential double ionization (NSDI) induced by electron-electron (e-e) correlation. A large variety of novel phenomena has been revealed in experiments during the past decades. However, the theoretical understanding and interpretation of this process is still far from being complete. The most accurate simulation, i.e. the exact solution of the time-dependent Schrödinger equation (TDSE) for two electrons in a laser field is computationally expensive. In order to overcome the difficulty, we proposed a feasible semiclassical model, in which we treat the tunneling ionization of the outmost electron quantum mechanically according to the ADK theory, sample the inner electron from microcanonical distribution and then evolve the two electrons with Newton's equations. With this model, we have successfully explained various NSDI phenomena, including the excessive DI yield, the energy spectra and angular distribution of photoelectrons. Very recently, it is adopted to reveal the physical mechanisms behind the fingerlike structure in the correlated electron momentum spectra, the unexpected correlation-anticorrelation transition close to the recollision threshold, and the anomalous NSDI of alkaline-earth-metal atoms in circularly polarized field. The obvious advantage of our model is that it gives time-resolved insights into the complex dynamics of NSDI, from the turn-on of the laser field to the final escape of the electrons, thus allowing us to disentangle and thoroughly analyze the underlying physical mechanisms.

  4. Studies on the Dynamic Mechanical Properties of the Composite Modified Double-Base Propellant,

    DTIC Science & Technology

    1986-05-29

    between the DII and PVC composite propellants asid depend on its binder system, and that the CMDB propellant has the spec;fic properties of both higher...the mechanical properties of cMDB propellants, is discussed by using a viscoelastometer. 1. Samples and Experimental Method 1.1 Samples The detailed...r -rr~rw.w w - W ’S - -’ -fj -9f W 2 W W- W- W- 1 From Figure 3.3 it is seen that the impulsive strength of CMDB propellant increases in two stages

  5. Separation mechanism for double cylinder with shrink fitting system used for ceramics conveying rollers

    NASA Astrophysics Data System (ADS)

    Li, Wenbin; Sakai, Hiromasa; Harada, Shota; Takase, Yasushi; Noda, Nao-Aki

    2011-09-01

    Steel conveying rollers used in hot rolling mills must be exchanged frequently at great cost because hot conveyed strips induce wear and deterioration on the surface of roller in short periods. In previous studies, new roller structure was considered which has a ceramics sleeve connected with two steel shafts at both ends by shrink fitting. Here, although the ceramics sleeve can be used for many years, the steel shafts sometimes have to be exchanged for maintenance and reconstruction under the corrosive atmosphere. Since the thermal expansion coefficient of steel is about five times larger than that of ceramics, it is necessary to investigate how to separate the shrink fitting system by heating outside of sleeve and cooling inside of the shaft. Although how to separate the real roller has been discussed in the previous study, the separation mechanism has not been clarified yet. Therefore, in this study, several types of more fundamental models are investigated to understand the separation mechanism of real roller by the application of the finite element method. The results may be useful for designs of new rollers.

  6. A double-ratchet mechanism of transcription elongation and its control

    NASA Astrophysics Data System (ADS)

    Ruckenstein, Andrei

    2005-03-01

    Transcription, the process by which the genetic information encoded in DNA is transferred into RNA, is the first step in gene expression and it is the step at which most regulation occurs. A detailed understanding of the structural and mechanistic aspects of each step of transcription (initiation, elongation, termination and regulation) is one of the holy grails of biology. Here we characterize the motion of RNA polymerase (RNAP), the multi-subunit molecular motor that carries out the transcription process, during the elongation stage. We argue that during elongation RNAP moves by a complex Brownian ratchet mechanism in which the translocation along DNA and the binding of nucleotides into RNAP's catalytic center are coupled to a fluctuating internal degree of freedom associated with a protein sub-unit (the F-bridge) of RNAP. More precisely, the model is defined by a set of kinetic equations^ describing the competition for the catalytic site between an incoming nucleotide, the 3'-end of RNA, and the F-bridge which in its bent conformation blocks the active center. An important aspect of the model is the incorporation of the three ``active'' processes describing (i) the ejection of bound nucleotides from the active center through steric clashes with either the F-bridge in its bent conformation or with the 3'-end of RNA; and (ii) the forward translocation induced by bending of the F-bridge pushing against the 3'-end of RNA. The ``active'' processes do not imply a ``power stroke'' mechanism since the energy driving them is purely thermal. Indeed the model displays a route by which the system uses thermal fluctuations to control the rate, processivity and fidelity of transcription already before the irreversible chemical incorporation step. Moreover, the model qualitatively explains many aspects of both bio-chemicalootnotetextBar-Nahum, G., Epshtein, V., Ruckenstein, A.E., Rafikov, R., Mustaev, A., and Nudler, E. A ratchet mechanism of transcription elongation and its

  7. The nature of massive neutrinos and multiple mechanisms in neutrinoless double-beta decay

    NASA Astrophysics Data System (ADS)

    Meroni, Aurora

    2015-11-01

    Determining the nature -Dirac or Majorana- of massive neutrinos is one of the most pressing and challenging problems in the field of neutrino physics. We discuss how one can possibly extract information on the couplings, if any, which might be involved in (ββ)_{0ν}-decay using a multi-isotope approach. We investigate as well the potential of combining data on the half-lives of nuclides with largely different Nuclear Matrix Elements such as 136Xe and of one or more of the four nuclei 76Ge, 82Se, 100Mo and 130Te, for discriminating between different pairs of noninterfering or interfering mechanisms of (ββ)_{0ν}-decay. The case studies do not extend to the evaluation of the theoretical uncertainties of the results, due to the nuclear matrix elements calculations and other causes.

  8. Structural Mechanism of Allosteric Activity Regulation in a Ribonucleotide Reductase with Double ATP Cones.

    PubMed

    Johansson, Renzo; Jonna, Venkateswara Rao; Kumar, Rohit; Nayeri, Niloofar; Lundin, Daniel; Sjöberg, Britt-Marie; Hofer, Anders; Logan, Derek T

    2016-06-07

    Ribonucleotide reductases (RNRs) reduce ribonucleotides to deoxyribonucleotides. Their overall activity is stimulated by ATP and downregulated by dATP via a genetically mobile ATP cone domain mediating the formation of oligomeric complexes with varying quaternary structures. The crystal structure and solution X-ray scattering data of a novel dATP-induced homotetramer of the Pseudomonas aeruginosa class I RNR reveal the structural bases for its unique properties, namely one ATP cone that binds two dATP molecules and a second one that is non-functional, binding no nucleotides. Mutations in the observed tetramer interface ablate oligomerization and dATP-induced inhibition but not the ability to bind dATP. Sequence analysis shows that the novel type of ATP cone may be widespread in RNRs. The present study supports a scenario in which diverse mechanisms for allosteric activity regulation are gained and lost through acquisition and evolutionary erosion of different types of ATP cone.

  9. 31 CFR 356.10 - What is the purpose of an auction announcement?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... announcement? 356.10 Section 356.10 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY BUREAU OF THE PUBLIC DEBT SALE AND ISSUE OF MARKETABLE...? By issuing an auction announcement, we provide public notice of the sale of bills, notes, and...

  10. 31 CFR 356.10 - What is the purpose of an auction announcement?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... announcement? 356.10 Section 356.10 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY BUREAU OF THE PUBLIC DEBT SALE AND ISSUE OF MARKETABLE...? By issuing an auction announcement, we provide public notice of the sale of bills, notes, and...

  11. 77 FR 73969 - Expanding the Economic and Innovation Opportunities of Spectrum Through Incentive Auctions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-12

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 1, 27 and 73 Expanding the Economic and Innovation Opportunities of Spectrum Through... implement an incentive auction of broadcast television spectrum. The NPRM set deadlines for filing...

  12. Ordering competition: the interactional accomplishment of the sale of art and antiques at auction.

    PubMed

    Heath, Christian; Luff, Paul

    2007-03-01

    Auctions provide an institutional solution to a social problem; they enable the legitimate pricing and exchange of goods where those goods are of uncertain value. In turn, auctions raise a number of social and organizational issues that are resolved within the interaction that arise in sales by auction. In this paper, we examine sales of fine art, antiques and objets d'art and explore the ways in which auctioneers mediate competition between buyers and establish a value for goods. In particular, we explore how bids are elicited, co-ordinated and revealed so as to rapidly escalate the price of goods in a transparent manner that enables the legitimate valuation and exchange of goods. In directing attention towards the significance of the social interaction, including talk, visual and material conduct, the paper contributes to the growing corpus of ethnographic studies of markets. It suggests that to understand the operation of markets and their outcomes, and to unpack issues of agency, trust and practice, we need to place the 'interaction order' at the heart of analytic agenda.

  13. 25 CFR 215.4 - Leases to be sold at public auction.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Leases to be sold at public auction. 215.4 Section 215.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEAD AND ZINC MINING... provided in the regulations in this part, no lead and zinc mining lease under this part of restricted...

  14. 25 CFR 215.4 - Leases to be sold at public auction.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Leases to be sold at public auction. 215.4 Section 215.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEAD AND ZINC MINING... provided in the regulations in this part, no lead and zinc mining lease under this part of restricted...

  15. 25 CFR 215.4 - Leases to be sold at public auction.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Leases to be sold at public auction. 215.4 Section 215.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEAD AND ZINC MINING... provided in the regulations in this part, no lead and zinc mining lease under this part of restricted...

  16. 25 CFR 215.4 - Leases to be sold at public auction.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Leases to be sold at public auction. 215.4 Section 215.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR ENERGY AND MINERALS LEAD AND ZINC MINING... provided in the regulations in this part, no lead and zinc mining lease under this part of restricted...

  17. Doesticks' Assault on Slavery: Style and Technique in "The Great Auction Sale, at Savannah, Georgia."

    ERIC Educational Resources Information Center

    Piacentino, Edward J.

    1987-01-01

    Analyzes "The Great Auction Sale of Slaves, at Savannah, Georgia" (1859), a popular work by Mortimer Neal Thompson, an American humorist better known by his pseudonym, Q.K. Philander Doesticks, P.B. The book is one of the most readable, credibly authentic accounts of the abuses of slavery. (BJV)

  18. 31 CFR 356.33 - Does the Treasury have any discretion in the auction process?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Does the Treasury have any discretion... CIRCULAR, PUBLIC DEBT SERIES NO. 1-93) Miscellaneous Provisions § 356.33 Does the Treasury have any discretion in the auction process? (a) We have the discretion to: (1) Accept, reject, or refuse to...

  19. 31 CFR 356.20 - How does the Treasury determine auction awards?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false How does the Treasury determine auction awards? 356.20 Section 356.20 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY BUREAU OF THE PUBLIC DEBT SALE AND ISSUE...

  20. 75 FR 57947 - Auction of VHF Commercial Television Station Construction Permits Scheduled for February 15, 2011...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-23

    ... page at http://www.fcc.gov/cgb/ecfs/ . I. Introduction 1. The Wireless Telecommunications and the Media... TTY: 202-418-0432. The Wireless Telecommunications Bureau requests that a copy of all comments and... INFORMATION CONTACT: Wireless Telecommunications Bureau, Auctions and Spectrum Access Division: For...

  1. See Art History in a New Light: Have an Art Auction

    ERIC Educational Resources Information Center

    Benter, Doris J.

    2008-01-01

    At Portledge School in Locust Valley, New York, ninth graders in their upper school study art history for one semester. The visual arts department has created a vigorous new syllabus culminating in an hour-long mock art auction. The department selects several art movements (e.g., Post-Impressionism, Cubism, Abstract Expressionism, Social Realism,…

  2. 49 CFR Appendix F to Part 599 - Salvage Auction Certification Form

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Salvage Auction Certification Form F Appendix F to Part 599 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY... CONSUMER ASSISTANCE TO RECYCLE AND SAVE ACT PROGRAM Pt. 599, App. F Appendix F to Part 599—Salvage...

  3. 49 CFR Appendix F to Part 599 - Salvage Auction Certification Form

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Salvage Auction Certification Form F Appendix F to Part 599 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY... CONSUMER ASSISTANCE TO RECYCLE AND SAVE ACT PROGRAM Pt. 599, App. F Appendix F to Part 599—Salvage...

  4. 49 CFR Appendix F to Part 599 - Salvage Auction Cerification Form

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Salvage Auction Cerification Form F Appendix F to Part 599 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY... CONSUMER ASSISTANCE TO RECYCLE AND SAVE ACT PROGRAM Pt. 599, App. F Appendix F to Part 599—Salvage...

  5. Teaching Undergraduate Money and Banking: T-Bill Auctions and Stock Market Models

    ERIC Educational Resources Information Center

    Saros, Daniel E.

    2009-01-01

    The author offers innovative approaches to 3 topics that are typically only briefly mentioned (if at all) in money and banking courses. The first topic is a Treasury bill auction experiment in which students have an opportunity to participate directly. The results from a class of 14 money and banking students are used to explain how an instructor…

  6. Revisiting "The Loophole of the Improved Secure Quantum Sealed-Bid Auction with Post-Confirmation and Solution"

    NASA Astrophysics Data System (ADS)

    Wang, Qing-Le; Zhang, Wei-Wei; Su, Qi

    2014-09-01

    Recently, Luo et al. make a detailed analysis on the security of quantum sealed-bid auction with post-confirmation protocol (Quantum Information Processing, Volume 11, Issue 6, pp 1359-1369, 2012) and present the corresponding improved strategy for its loophole. Unfortunately, we find their improved version is still not as secure as expected, since it is vulnerable to malicious bidders in collusion with the auctioneer. And there is an unreasonable suspicion in the honesty of the auctioneer for special situation. Then we propose an improved strategy, which can perfectly defeat kinds of attacks.

  7. Mechanisms of cellular penetration and nuclear localization of an anti-double strand DNA autoantibody.

    PubMed

    Zack, D J; Stempniak, M; Wong, A L; Taylor, C; Weisbart, R H

    1996-09-01

    An anti-dsDNA Ab, mAb 3E10, was identified that bound membranes of fixed human renal tubular cells, penetrated live murine renal tubular cells in vivo, and localized in the cell nucleus. mAb 3E10 binds both dsDNA and an extracellular matrix protein, HP8/HEVIN, expressed in high endothelial venules. Previous studies showed both shared and distinct binding determinants of mAb 3E10 VH for DNA and HP8/HEVIN. To independently assess the requirement of DNA and HP8/HEVIN in cellular penetration, site-directed mutants of mAb 3E10 VH and V kappa were studied for penetrating kidney cell lines. The results showed that residues required for binding DNA, but not HP8/HEVIN, were necessary for Ab penetration, indicating that cellular penetration required the presence of DNA or binding of Ab to a membrane determinant precisely resembling DNA. Ab Fab penetrated cells, indicating that neither the Fc nor multivalent Ab binding is necessary for cellular penetration. Ab synthesized in the cytoplasm as a result of deleting heavy and light chain signal peptides was not translocated to the nucleus, indicating a mechanism distinct from the usual protein nuclear localization signals and suggesting the need for a membrane-mediated pathway or for post-translational modification of the Ab.

  8. Double-Barrier mechanism for chromium immobilization: A quantitative study of crystallization and leachability.

    PubMed

    Liao, Changzhong; Tang, Yuanyuan; Liu, Chengshuai; Shih, Kaimin; Li, Fangbai

    2016-07-05

    Glass-ceramics are well known for the excellent combination properties provided by their components, a glassy matrix and crystalline phases, and have promising applications in the immobilization and detoxification of solid waste containing toxic metals. Glass-ceramic products were successfully synthesized in CaO-MgO-SiO2-Al2O3 -Cr2O3 system. Two key measures--partitioning ratio of Cr in the spinel and Cr leaching ratio--were used to investigate the mechanism of Cr immobilization in the glass-ceramic products. The results of powder X-ray diffraction revealed that both spinel and diopside were major crystalline phases in the products. The value of x in the MgCr(x)Al(2-x)O4 spinel was highly related to the amount of Cr2O3 added to the glass-ceramic system. As Cr2O3 content increased, the proportion of spinel phase increased, while that of glass phase decreased. The partitioning ratio of Cr in spinel phase was about 70% for 2 wt.% Cr2O3, and increased to 90% when loaded with 10 wt.% of Cr2O3. According to the results of the prolonged toxicity characteristic leaching procedure, the Cr leaching ratio decreased with the increase of Cr partitioning ratio into the spinel phase. The findings of this study clearly indicate that glass-ceramic formed by spinel structure and residual glass successfully immobilized Cr.

  9. 77 FR 7152 - Mobility Fund Phase I Auction Scheduled for September 27, 2012; Comment Sought on Competitive...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-10

    .... If commenters propose to use different road categories, they should explain their reasoning and... bids, the auction system would use a mathematical optimization procedure to identify the set of...

  10. 78 FR 72081 - Closed Auction of AM Broadcast Construction Permits Scheduled for May 6, 2014; Comment Sought on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-02

    ... balances speed with the bidders' need to study round results and adjust their bidding strategies. Under... the close of the auction. With these considerations in mind, the Bureaus propose the upfront...

  11. 76 FR 3892 - Auction of FM Broadcast Construction Permits Rescheduled for April 27, 2011; Notice and Filing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-21

    ... considerations mentioned in the Auction 91 Procedures Public Notice do not comprise an exhaustive list of steps... section. Applicants should note that unjust enrichment provisions apply to a winning bidder that...

  12. The influence of an online auction's product price and e-retailer reputation on consumers' perception, attitude, and behavioral intention.

    PubMed

    Wu, Wann-Yih; Huang, Po-Ching; Fu, Chen-Su

    2011-06-01

    Online auctions combine the conventional auction model with information technology. However, information asymmetry within such auctions causes risks and uncertainties that influence consumer purchase intentions. In this study, a 2 (product price: high vs. low) × 2 (e-retailer reputation: high vs. low) experimental design was used to understand whether the product price and e-retailer reputation will influence consumers' perceived risk, attitude toward the website and purchase intention. The results of this study indicate that perceived risk negatively influences consumer attitude toward the website and online purchase intention, while consumer attitude toward the website positively influences purchase intention. Moreover, involvement moderates the influence of product price and e-retailer reputation only on social risk but does not have a significant effect on consumer attitude toward the website. This study contributes to a more comprehensive understanding of online auction users' behavior. Finally, the managerial implications, limitations and future research directions are also provided.

  13. In vitro MRI of biodegradable hybrid (iron oxide/polycaprolactone) magnetic nanoparticles prepared via modified double emulsion evaporation mechanism.

    PubMed

    Ahmed, Naveed; Ahmad, Nasir M; Fessi, Hatem; Elaissari, Abdelhamid

    2015-06-01

    Hybrid magnetic particles are being applied in biomedical field for various aims. One of such aim is use of magnetic particles for diagnostic purposes especially in imaging mechanisms. In vitro magnetic resonance imaging of biodegradable hybrid (iron oxide/polycaprolactone) magnetic nanoparticles is carried out. Hybrid magnetic nanoparticles were prepared by encapsulation of iron oxide nanoparticles (IONPs) in polycaprolactone (PCL) via modified double emulsion evaporation technique. Both the IONPs and hybrid nanoparticles were characterized for their sizes, zeta potential, microscopic, thermogravimetric, and magnetism. Prepared particles were investigated for T1 and T2 weighted enhancement of contrast in vitro in water. A comparison of the prepared particles was done with commercially available Gadolinium for the contrast efficiency in MRI. Results showed the prepared particles exhibited nanosize range, good morphology and superparamagnetic character. The enhancement in the MRI contrast of the prepared particles was observed and found to depend on type of the prepared particles. Comparison of the MRI contrast of the prepared particles with the commercial Gadolinium suggests their usefulness as T2 contrast agent.

  14. Stimulating somatosensory psychophysics: a double-blind, sham-controlled study of the neurobiological mechanisms of tDCS

    PubMed Central

    Hanley, Claire J.; Tommerdahl, Mark; McGonigle, David J.

    2015-01-01

    The neuromodulation technique transcranial direct current stimulation (tDCS) is thought to produce its effects on behavior by altering cortical excitability. Although the mechanisms underlying the observed effects are thought to rely on the balance of excitatory and inhibitory neurotransmission, the physiological principles of the technique are not completely understood. In this study, we examine the influence of tDCS on vibrotactile adaptation, using a simple amplitude discrimination paradigm that has been shown to exhibit modifications in performance due to changes in inhibitory neurotransmission. Double-blind tDCS (Anodal/Sham) of 1 mA was delivered for 600 s to electrodes positioned in a somatosensory/contralateral orbit montage. Stimulation was applied as part of a pre/post design, between blocks of the behavioral tasks. In accordance with previous work, results obtained before the application of tDCS indicated that amplitude discrimination thresholds were significantly worsened during adaptation trials, compared to those achieved at baseline. However, tDCS failed to modify amplitude discrimination performance. Using a Bayesian approach, this finding was revealed to constitute substantial evidence for the null hypothesis. The failure of DC stimulation to alter vibrotactile adaptation thresholds is discussed in the context of several factors that may have confounded the induction of changes in cortical plasticity. PMID:26500499

  15. I-SceI endonuclease, a new tool for studying DNA double-strand break repair mechanisms in Drosophila.

    PubMed Central

    Bellaiche, Y; Mogila, V; Perrimon, N

    1999-01-01

    As a step toward the development of a homologous recombination system in Drosophila, we have developed a methodology to target double-strand breaks (DSBs) to a specific position in the Drosophila genome. This method uses the mitochondrial endonuclease I-SceI that recognizes and cuts an 18-bp restriction site. We find that >6% of the progeny derived from males that carry a marker gene bordered by two I-SceI sites and that express I-SceI in their germ line lose the marker gene. Southern blot analysis and sequencing of the regions surrounding the I-SceI sites revealed that in the majority of the cases, the introduction of DSBs at the I-SceI sites resulted in the complete deletion of the marker gene; the other events were associated with partial deletion of the marker gene. We discuss a number of applications for this novel technique, in particular its use to study DSB repair mechanisms. PMID:10388822

  16. Assays for DNA double-strand break repair by microhomology-based end-joining repair mechanisms.

    PubMed

    Kostyrko, Kaja; Mermod, Nicolas

    2016-04-07

    DNA double stranded breaks (DSBs) are one of the most deleterious types of DNA lesions. The main pathways responsible for repairing these breaks in eukaryotic cells are homologous recombination (HR) and non-homologous end-joining (NHEJ). However, a third group of still poorly characterized DSB repair pathways, collectively termed microhomology-mediated end-joining (MMEJ), relies on short homologies for the end-joining process. Here, we constructed GFP reporter assays to characterize and distinguish MMEJ variant pathways, namely the simple MMEJ and the DNA synthesis-dependent (SD)-MMEJ mechanisms. Transfection of these assay vectors in Chinese hamster ovary (CHO) cells and characterization of the repaired DNA sequences indicated that while simple MMEJ is able to mediate relatively efficient DSB repair if longer microhomologies are present, the majority of DSBs were repaired using the highly error-prone SD-MMEJ pathway. To validate the involvement of DNA synthesis in the repair process, siRNA knock-down of different genes proposed to play a role in MMEJ were performed, revealing that the knock-down of DNA polymerase θ inhibited DNA end resection and repair through simple MMEJ, thus favoring the other repair pathway. Overall, we conclude that this approach provides a convenient assay to study MMEJ-related DNA repair pathways.

  17. Study of the negative ion extraction mechanism from a double-ion plasma in negative ion sources

    SciTech Connect

    Goto, I.; Nishioka, S.; Hatayama, A.; Miyamoto, K.

    2015-04-08

    We have developed a 2D3V-PIC model of the extraction region, aiming to clarify the basic extraction mechanism of H{sup −} ions from the double-ion plasma in H{sup −} negative ion sources. The result shows the same tendency of the H{sup −} ion density n{sub H{sup −}} as that observed in the experiments, i.e.,n{sub H{sup −}} in the upstream region away from the plasma meniscus (H{sup −} emitting surface) has been reduced by applying the extraction voltage. At the same time, relatively slow temporal oscillation of the electric potential compared with the electron plasma frequency has been observed in the extraction region. Results of the systematic study using a 1D3V-PIC model with the uniform magnetic field confirm the result that the electrostatic oscillation is identified to be lower hybrid wave. The effect of this oscillation on the H{sup −} transport will be studied in the future.

  18. Scaling of volume to surface ratio and doubling time in growing unicellular organisms: Do cells appear quantum-mechanical systems?

    NASA Astrophysics Data System (ADS)

    Atanasov, Atanas Todorov

    2014-10-01

    The scaling of physical and biological characteristics of the living organisms is a basic method for searching of new biophysical laws. In series of previous studies the author showed that in Poikilotherms, Mammals and Aves, the volume to surface ratio V×S-1 (m) of organisms is proportional to their generation time Tgt(s) via growth rate v (m s-1): V×S-1 = vgr×Tr. The power and the correlation coefficients are near to 1.0. Aim of this study is: i) to prove with experimental data the validity of the above equation for Unicellular organisms and ii) to show that perhaps, the cells are quantum-mechanical systems. The data for body mass M (kg), density ρ (kg/m3), minimum and maximum doubling time Tdt (s) for 50 unicellular organisms are assembled from scientific sources, and the computer program `Statistics' is used for calculations. In result i) the analytical relationship from type: V×S-1 = 4.46ṡ10-11×Tdt was found, where vgr = 4.46×10-11 m/s and ii) it is shown that the products between cell mass M, cell length expressed by V/S ratio and growth rate vgr satisfied the Heisenberg uncertainty principle i.e. the inequalities V/S×M×vgr>h/2π and Tdt×M×vgr2>h/2π are valid, where h= 6.626×10-34 Jṡs is the Planck constant. This rise the question: do cells appear quantum-mechanical systems?

  19. Scaling of volume to surface ratio and doubling time in growing unicellular organisms: Do cells appear quantum-mechanical systems?

    SciTech Connect

    Atanasov, Atanas Todorov

    2014-10-06

    The scaling of physical and biological characteristics of the living organisms is a basic method for searching of new biophysical laws. In series of previous studies the author showed that in Poikilotherms, Mammals and Aves, the volume to surface ratio V×S{sup −1} (m) of organisms is proportional to their generation time T{sub gt}(s) via growth rate v (m s{sup −1}): V×S{sup −1} = v{sub gr}×T{sup r}. The power and the correlation coefficients are near to 1.0. Aim of this study is: i) to prove with experimental data the validity of the above equation for Unicellular organisms and ii) to show that perhaps, the cells are quantum-mechanical systems. The data for body mass M (kg), density ρ (kg/m{sup 3}), minimum and maximum doubling time T{sub dt} (s) for 50 unicellular organisms are assembled from scientific sources, and the computer program ‘Statistics’ is used for calculations. In result i) the analytical relationship from type: V×S{sup −1} = 4.46⋅10{sup −11}×T{sub dt} was found, where v{sub gr} = 4.46×10{sup −11} m/s and ii) it is shown that the products between cell mass M, cell length expressed by V/S ratio and growth rate v{sub gr} satisfied the Heisenberg uncertainty principle i.e. the inequalities V/S×M×v{sub gr}>h/2π and T{sub dt}×M×v{sub gr}{sup 2}>h/2π are valid, where h= 6.626×10{sup −34} J⋅s is the Planck constant. This rise the question: do cells appear quantum-mechanical systems?.

  20. Double screening

    SciTech Connect

    Gratia, Pierre; Hu, Wayne; Joyce, Austin; Ribeiro, Raquel H.

    2016-06-15

    Attempts to modify gravity in the infrared typically require a screening mechanism to ensure consistency with local tests of gravity. These screening mechanisms fit into three broad classes; we investigate theories which are capable of exhibiting more than one type of screening. Specifically, we focus on a simple model which exhibits both Vainshtein and kinetic screening. We point out that due to the two characteristic length scales in the problem, the type of screening that dominates depends on the mass of the sourcing object, allowing for different phenomenology at different scales. We consider embedding this double screening phenomenology in a broader cosmological scenario and show that the simplest examples that exhibit double screening are radiatively stable.

  1. Shear-tensile crack as a tool for reliable estimates of the non-double-couple mechanism: West Bohemia-Vogtland earthquake 1997 swarm

    NASA Astrophysics Data System (ADS)

    Šílený, Jan; Horálek, Josef

    2016-10-01

    Shear-tensile crack is a model for an earthquake mechanism that is more constrained than the moment tensor but that can still describe a non-shear focus. As such, the shear-tensile crack model is more robust than the moment tensor model and yields more reliable estimates for the earthquake mechanism. Such an advantage verifies the credibility of the non-double-couple component found for some events of the 1997 West Bohemia-Vogtland earthquake swarm. As expected, in several cases, a significantly resolved non-double-couple component was obtained where the moment tensor approach failed. Additionally, for non-shear sources, the shear-tensile crack model offers optimization of the Poisson number within the focus, concurrently with retrieval of the mechanism. However, results obtained for the joint inversion of the 1997 swarm indicate that resolution is low. A series of synthetic experiments indicated that limited observations during 1997 were not the cause. Rather, hypothetical experiments of both very good and extremely poor network configurations similarly yielded a low resolution for the Poisson number. Applying this method to data for recent swarms is irrelevant because the small non-double-couple components detected within the inversion are spurious and, thus, the events are pure double-couple phenomena.

  2. Double Mantle Plume Upwelling—A Possible Formation Mechanism of Beta Plateau and Devana Chasma,Venus

    NASA Astrophysics Data System (ADS)

    Ding, N.

    2009-12-01

    Ning Ding,Zuoxun Zeng,China University of Geosciences,Wuhan,430074,China NingDing.eagle@gmail.com Introduction:Venus represents a‘one plate planet’[1],and the uplift,fractures and volcanism in Beta Regio on Venus are considered to be formed by lithosphere uplift driven by a hot plume[2]. Based on the double peaking saddle landform,we suggest the tectonic pattern of double mantle plume upwelling to interpret the formation mechanism of Beta Plateau and Devana Chasma.We take a physical modeling to validate this possibility. Model:There is no ductile shear in Venus[3],so we use quartz sands to simulate the crust of Venus.We use two wood stickes 1.5cm in diameter rising from the rubber canvas slowly and straight till about half of the model,then falling down slowly and straight.The base is a hard rubber plate,in the center of which,there are two holes 3cm in diameter,and the distance between them is 5cm.The holes are covered by rubber canvas.We use the quartz sands in colours of white, red and black with particle size of 70 mess as the model materials. Result:Fig.1:At the beginning of the wood stickes upwelling,only fine radial cracks are formed above the upwelling from central to outside.With the upwelling continue,surface energy of the fine radial cracks increase and make the cracks unstable,finally,the fine radial cracks connect each other and form a fracture zone.And then the two mantle plume downwelling,the fracture zone is developed to form a chasma at the end. Fig.2:The four profiles all form reverse faults outside and normal faults inside.But the difference is the faults in the middle of the chasma goes deeper than others.It is the pattern of Beta Plateau where the tectonic rising is cut by Devana Chasma zone in the topographic features. Fig.3:From the tow fig., we can see two points similar:a.the elevation is high and distribution area is large around the area of two upwelling and it is high around the area of chasma,but the distribution area is small

  3. Analytical approaches for clarification of DNA-double decker phthalocyanine binding mechanism: As an alternative anticancer chemotherapeutic.

    PubMed

    Bağda, Esra; Yabaş, Ebru; Bağda, Efkan

    2017-02-05

    In the present study a novel water soluble double-decker phthalocyanine was synthesized and calf thymus DNA interaction of the synthesized double-decker phthalocyanine was investigated. 5-(3-pyridyl)-1,3,4-oxadiazole substituted phthalonitrile 1 was prepared by a nucleophilic displacement reaction of 4-nitrophthalonitrile with 5-(3-pyridyl)-1,3,4-oxadiazole-2-thiol. Lutetium(III) double-decker phthalocyanine 2 was prepared by cyclotetramerization of compound 1. Water soluble lutetium(III) double-decker phthalocyanine 3 was prepared with quaternarization of compound 2. The synthesized double-decker phthalocyanine and calf thymus DNA interaction was investigated with UV-vis titrimetric methods, gel electrophoresis, and viscosity measurements. The fluorometric ethidium bromide replacement assay was conducted to clarify the binding mode of water soluble double-decker phthalocyanine. The thermodynamic parameters for interaction, K, ΔG(0), ΔH(0) and ΔS(0) were calculated between the temperature ranges of 25°C-75°C. To the best of our knowledge, this is the first study about a double-decker phthalocyanine and DNA interaction.

  4. Analytical approaches for clarification of DNA-double decker phthalocyanine binding mechanism: As an alternative anticancer chemotherapeutic

    NASA Astrophysics Data System (ADS)

    Bağda, Esra; Yabaş, Ebru; Bağda, Efkan

    2017-02-01

    In the present study a novel water soluble double-decker phthalocyanine was synthesized and calf thymus DNA interaction of the synthesized double-decker phthalocyanine was investigated. 5-(3-pyridyl)-1,3,4-oxadiazole substituted phthalonitrile 1 was prepared by a nucleophilic displacement reaction of 4-nitrophthalonitrile with 5-(3-pyridyl)-1,3,4-oxadiazole-2-thiol. Lutetium(III) double-decker phthalocyanine 2 was prepared by cyclotetramerization of compound 1. Water soluble lutetium(III) double-decker phthalocyanine 3 was prepared with quaternarization of compound 2. The synthesized double-decker phthalocyanine and calf thymus DNA interaction was investigated with UV-vis titrimetric methods, gel electrophoresis, and viscosity measurements. The fluorometric ethidium bromide replacement assay was conducted to clarify the binding mode of water soluble double-decker phthalocyanine. The thermodynamic parameters for interaction, K, ΔG0, ΔH0 and ΔS0 were calculated between the temperature ranges of 25 °C-75 °C. To the best of our knowledge, this is the first study about a double-decker phthalocyanine and DNA interaction.

  5. The transition mechanism from a symmetric single period discharge to a period-doubling discharge in atmospheric helium dielectric-barrier discharge

    SciTech Connect

    Zhang, Dingzong; Wang, Yanhui; Wang, Dezhen

    2013-06-15

    Period-doubling and chaos phenomenon have been frequently observed in atmospheric-pressure dielectric-barrier discharges. However, how a normal single period discharge bifurcates into period-doubling state is still unclear. In this paper, by changing the driving frequency, we study numerically the transition mechanisms from a normal single period discharge to a period-doubling state using a one-dimensional self-consistent fluid model. The results show that before a discharge bifurcates into a period-doubling state, it first deviates from its normal operation and transforms into an asymmetric single period discharge mode. Then the weaker discharge in this asymmetric discharge will be enhanced gradually with increasing of the frequency until it makes the subsequent discharge weaken and results in the discharge entering a period-doubling state. In the whole transition process, the spatial distribution of the charged particle density and the electric field plays a definitive role. The conclusions are further confirmed by changing the gap width and the amplitude of the applied voltage.

  6. Equilibrium Strategy and Population-Size Effects in Lowest Unique Bid Auctions

    NASA Astrophysics Data System (ADS)

    Pigolotti, Simone; Bernhardsson, Sebastian; Juul, Jeppe; Galster, Gorm; Vivo, Pierpaolo

    2012-02-01

    In lowest unique bid auctions, N players bid for an item. The winner is whoever places the lowest bid, provided that it is also unique. We use a grand canonical approach to derive an analytical expression for the equilibrium distribution of strategies. We then study the properties of the solution as a function of the mean number of players, and compare them with a large data set of internet auctions. The theory agrees with the data with striking accuracy for small population-size N, while for larger N a qualitatively different distribution is observed. We interpret this result as the emergence of two different regimes, one in which adaptation is feasible and one in which it is not. Our results question the actual possibility of a large population to adapt and find the optimal strategy when participating in a collective game.

  7. Biased Random-Key Genetic Algorithms for the Winner Determination Problem in Combinatorial Auctions.

    PubMed

    de Andrade, Carlos Eduardo; Toso, Rodrigo Franco; Resende, Mauricio G C; Miyazawa, Flávio Keidi

    2015-01-01

    In this paper we address the problem of picking a subset of bids in a general combinatorial auction so as to maximize the overall profit using the first-price model. This winner determination problem assumes that a single bidding round is held to determine both the winners and prices to be paid. We introduce six variants of biased random-key genetic algorithms for this problem. Three of them use a novel initialization technique that makes use of solutions of intermediate linear programming relaxations of an exact mixed integer linear programming model as initial chromosomes of the population. An experimental evaluation compares the effectiveness of the proposed algorithms with the standard mixed linear integer programming formulation, a specialized exact algorithm, and the best-performing heuristics proposed for this problem. The proposed algorithms are competitive and offer strong results, mainly for large-scale auctions.

  8. Collective induction without cooperation? Learning and knowledge transfer in cooperative groups and competitive auctions.

    PubMed

    Maciejovsky, Boris; Budescu, David V

    2007-05-01

    There is strong evidence that groups perform better than individuals do on intellective tasks with demonstrably correct solutions. Typically, these studies assume that group members share common goals. The authors extend this line of research by replacing standard face-to-face group interactions with competitive auctions, allowing for conflicting individual incentives. In a series of studies involving the well-known Wason selection task, they demonstrate that competitive auctions induce learning effects equally impressive as those of standard group interactions, and they uncover specific and general knowledge transfers from these institutions to new reasoning problems. The authors identify payoff feedback and information pooling as the driving factors underlying these findings, and they explain these factors within the theoretical framework of collective induction.

  9. A Supplier Bidding Strategy Through Q-Learning Algorithm in Electricity Auction Markets

    NASA Astrophysics Data System (ADS)

    Xiong, Gaofeng; Hashiyama, Tomonori; Okuma, Shigeru

    One of the most important issues for power suppliers in the deregulated electric industry is how to bid into the electricity auction market to satisfy their profit-maximizing goals. Based on the Q-Learning algorithm, this paper presents a novel supplier bidding strategy to maximize supplier’s profit in the long run. In this approach, the supplier bidding strategy is viewed as a kind of stochastic optimal control problem and each supplier can learn from experience. A competitive day-ahead electricity auction market with hourly bids is assumed here, where no supplier possesses the market power. The dynamics and the incomplete information of the market are considered. The impacts of suppliers’ strategic bidding on the market price are analyzed under uniform pricing rule and discriminatory pricing rule. Agent-based simulations are presented. The simulation results show the feasibility of the proposed bidding strategy.

  10. A Q-Learning-Based Supplier Bidding Strategy in Electricity Auction Market

    NASA Astrophysics Data System (ADS)

    Xiong, Gaofeng; Hashiyama, Tomonori; Okuma, Shigeru

    One of the most important issues for power suppliers in the deregulated electric industry is how to bid into the electricity auction market to satisfy their profit-maximizing goals. Based on the Q-Learning algorithm, this paper presents a novel supplier bidding strategy to maximize supplier’s profit in the long run. In this approach, the supplier bidding strategy is viewed as one kind of stochastic optimal control problem and each supplier can learn from experience. A competitive day-ahead electricity auction market with hourly bids is assumed here, where no supplier possesses the market power and all suppliers winning the market are paid based on their own bid prices. The dynamics and the incomplete information of the market are considered. The impact of suppliers’ strategic bidding on the market price is analyzed. Agent-based simulations are presented. The simulation results show the feasibility of the proposed bidding strategy.

  11. Research at the auction block: Problems for the fair benefits approach to international research.

    PubMed

    London, Alex John; Zollman, Kevin J S

    2010-01-01

    The "fair benefits" approach to international research is designed to produce results that all can agree are fair without taking a stand on divisive questions of justice. But its appealing veneer of collaboration masks ambiguities at both a conceptual and an operational level. An attempt to put it into practice would look a lot like an auction, leaving little reason to think the outcomes will satisfy even minimal conditions of fairness.

  12. The mechanism of adenosine to inosine conversion by the double-stranded RNA unwinding/modifying activity: A high-performance liquid chromatography-mass spectrometry analysis

    SciTech Connect

    Polson, A.G.; Crain, P.F.; Pomerantz, S.C.; McCloskey, J.A.; Bass, B.L. )

    1991-12-10

    The authors have used directly combined high-performance liquid chromatography-mass spectrometry (LC/MS) to examine the mechanism of the reaction catalyzed by the double-stranded RNA unwinding/modifying activity. A double-stranded RNA substrate in which all adenosines were uniformly labeled with {sup 13}C was synthesized. An LC/MS analysis of the nucleoside products from the modified, labeled substrate confirmed that adenosine is modified to inosine during the unwinding/modifying reaction. Most importantly, they found that no carbons are exchanged during the reaction. By including H{sub 2} {sup 18}O in the reaction, they showed that water serves efficiently as the oxygen donor in vitro. These results are consistent with a hydrolytic deamination mechanism and rule out a base replacement mechanism. Although the double-stranded RNA unwinding/modifying activity appears to utilize a catalytic mechanism similar to that of adenosine deaminase, coformycin, a transition-state analogue, will not inhibit the unwinding/modifying activity.

  13. Improving the secrecy rate by turning foes to allies: An auction scheme

    NASA Astrophysics Data System (ADS)

    Ma, Ya-Yan; Wang, Bao-Yun

    2015-09-01

    Security against eavesdroppers is a critical issue in cognitive radio networks (CRNs). In this paper, a scenario consisting of one primary pair and multiple secondary pairs is considered. The secondary transmitters (STs) work in half-duplex mode and they are potential eavesdroppers on the primary transmission unless they are allowed to simultaneously transmit with the primary transmitter (PT). A modified second-price sealed-bid auction scheme is employed to model the interaction between the PT and STs. With the proposed auction scheme, the hostile relationship between the PT and STs is transformed into a cooperative relationship. An iterative algorithm based on the max-min criteria is proposed to find the optimal bidding power of the STs for an access chance in the presence of multiple eavesdroppers. Numerical results show that the proposed auction scheme not only improves the PT’s security but also increases the access opportunities of the STs. Project supported by the National Natural Science Foundation of China (Grant Nos. 61271232 and 61372126) and the University Postgraduate Research and Innovation Project in Jiangsu Province, China (Grant No. CXZZ12-0472).

  14. Probing the Mechanism of the Double C—H (De)Activation Route of a Ru-Based Olefin Metathesis Catalyst

    NASA Astrophysics Data System (ADS)

    Poater, Albert; Cavallo, Luigi

    A theoretical study of a double C—H activation mechanism that deactivates a family of second generation Ru-based catalysts is presented. DFT calculations are used to rationalize the complex mechanistic pathway from the starting precatalyst to the experimentally characterized decomposition products. In particular, we show that all the intermediates proposed by Grubbs and coworkers are indeed possible intermediates in the deactivation pathway, although the sequence of steps is somewhat different

  15. Elaboration and controlling excited state double proton transfer mechanism of 2,5-bis(benzoxazol-2-yl)thiophene-3,4-diol

    PubMed Central

    Zhao, Jinfeng; Zheng, Yujun

    2017-01-01

    In the present work, we theoretically illuminate the excited state double proton transfer (ESDPT) process about a novel synthesized system 2,5-bis(benzoxazol-2-yl)thiophene-3,4-diol (BBTD). Minor changes of both structure and charge redistribution deriving from photoexcitation result in obviously different excited state dynamical process. Exploration about our constructed S1-state potential energy surface (PES) indicates a stepwise ESDPT mechanism for BBTD. In addition, we present a new mechanism about regulating and controlling stepwise ESDPT process via external electric field. PMID:28327590

  16. Resolution of concerted versus sequential mechanisms in photo-induced double-proton transfer reaction in 7-azaindole H-bonded dimer

    PubMed Central

    Catalán, Javier; del Valle, Juan Carlos; Kasha, Michael

    1999-01-01

    The experimental and theoretical bases for a synchronous or concerted double-proton transfer in centro-symmetric H-bonded electronically excited molecular dimers are presented. The prototype model is the 7-azaindole dimer. New research offers confirmation of a concerted mechanism for excited-state biprotonic transfer. Recent femtosecond photoionization and coulombic explosion techniques have given rise to time-of-flight MS observations suggesting sequential two-step biprotonic transfer for the same dimer. We interpret the overall species observed in the time-of-flight experiments as explicable without conflict with the concerted mechanism of proton transfer. PMID:10411876

  17. Elaboration and controlling excited state double proton transfer mechanism of 2,5-bis(benzoxazol-2-yl)thiophene-3,4-diol

    NASA Astrophysics Data System (ADS)

    Zhao, Jinfeng; Zheng, Yujun

    2017-03-01

    In the present work, we theoretically illuminate the excited state double proton transfer (ESDPT) process about a novel synthesized system 2,5-bis(benzoxazol-2-yl)thiophene-3,4-diol (BBTD). Minor changes of both structure and charge redistribution deriving from photoexcitation result in obviously different excited state dynamical process. Exploration about our constructed S1-state potential energy surface (PES) indicates a stepwise ESDPT mechanism for BBTD. In addition, we present a new mechanism about regulating and controlling stepwise ESDPT process via external electric field.

  18. 78 FR 65982 - Auction of H Block Licenses in the 1915-1920 MHz and 1995-2000 MHz Bands Rescheduled for January...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-04

    ... participant in Auction 96 to continue such research throughout the auction. The due diligence considerations.... Applicants should note that unjust enrichment provisions apply to a winning bidder that utilizes a bidding... requires the consideration of certain leasing and resale (including wholesale) relationships--referred...

  19. Double Your Pleasure, Double Your Funds.

    ERIC Educational Resources Information Center

    McCall, Miles; Sitton, Bob

    1999-01-01

    Discusses a variety of fun activities that college and universities can develop as alumni fund-raising events: a golf tournament; scholarship auctions (silent, on-the-spot, live televised, and live); charitable raffles; duck dashes; themed banquets; and a tuition raffle. (MSE)

  20. A Winner Determination Algorithm for Combinatorial Auctions Based on Hybrid Artificial Fish Swarm Algorithm

    NASA Astrophysics Data System (ADS)

    Zheng, Genrang; Lin, ZhengChun

    The problem of winner determination in combinatorial auctions is a hotspot electronic business, and a NP hard problem. A Hybrid Artificial Fish Swarm Algorithm(HAFSA), which is combined with First Suite Heuristic Algorithm (FSHA) and Artificial Fish Swarm Algorithm (AFSA), is proposed to solve the problem after probing it base on the theories of AFSA. Experiment results show that the HAFSA is a rapidly and efficient algorithm for The problem of winner determining. Compared with Ant colony Optimization Algorithm, it has a good performance with broad and prosperous application.

  1. Dielectric relaxation and electrical conduction mechanism in A2HoSbO6 (A=Ba, Sr, Ca) Double Perovskite Ceramics: An impedance spectroscopic analysis

    NASA Astrophysics Data System (ADS)

    Halder, Saswata; Dutta, Alo; Sinha, T. P.

    2017-03-01

    The AC electrical properties of polycrystalline double perovskite oxides A2HoSbO6 (A=Ba, Sr, Ca; AHS) synthesized by solid state reaction technique has been explored by using impedance spectroscopic studies. The Rietveld refinement of the room temperature X-ray diffraction data show that Ba2HoSbO6 (BHS) has cubic phase and Sr2HoSbO6 (SHS) and Ca2HoSbO6 (CHS) crystallize in monoclinic phase. The samples show significant frequency dispersion in their dielectric properties. The polydispersive nature of the relaxation mechanism is explained by the modified Cole-Cole model. The scaling behavior of dielectric loss indicate the temperature independence of the relaxation mechanism. The magnitude of the activation energy indicates that the hopping mechanism is responsible for carrier transport in AHS. The frequency dependent conductivity spectra follow the double power law. Impedance spectroscopic data presented in the Nyquist plot (Z" versus Z‧) are used to identify an equivalent circuit along with to know the grain, grain boundary and interface contributions. The constant phase element (CPE) is used to analyze the experimental response of BHS, SHS and CHS comprehending the contribution of different microstructural features to the conduction process. The temperature dependent electrical conductivity shows a semiconducting behavior.

  2. An Effective Power Saving Mechanism for IEEE 802.11 PSM in Double-Layered Mobile P2P Systems

    NASA Astrophysics Data System (ADS)

    Lee, Ju-Hee; Kim, Taek-Hun; Song, Jin-Woo; Lee, Kwang-Jo; Yang, Sung-Bong

    In this paper, we propose a scheme for double-layered mobile P2P systems that enhances energy efficiency by modifying PSM(Power Saving Mode) defined in 802.11. The proposed scheme lengthens the beacon interval adaptively and adopts a known power saving scheme for more power saving. The experimental results showed that the proposed scheme improved 58.3% in terms of the average energy saving and 10% in terms of the average success ratio for file searches over the system with the standard PSM.

  3. Replication-Dependent and Transcription-Dependent Mechanisms of DNA Double-Strand Break Induction by the Topoisomerase 2-Targeting Drug Etoposide

    PubMed Central

    Tammaro, Margaret; Barr, Peri; Ricci, Brett; Yan, Hong

    2013-01-01

    Etoposide is a DNA topoisomerase 2-targeting drug widely used for the treatment of cancer. The cytoxicity of etoposide correlates with the generation of DNA double-strand breaks (DSBs), but the mechanism of how it induces DSBs in cells is still poorly understood. Catalytically, etoposide inhibits the re-ligation reaction of Top2 after it nicks the two strands of DNA, trapping it in a cleavable complex consisting of two Top2 subunits covalently linked to the 5’ ends of DNA (Top2cc). Top2cc is not directly recognized as a true DSB by cells because the two subunits interact strongly with each other to hold the two ends of DNA together. In this study we have investigated the cellular mechanisms that convert Top2ccs into true DSBs. Our data suggest that there are two mechanisms, one dependent on active replication and the other dependent on proteolysis and transcription. The relative contribution of each mechanism is affected by the concentration of etoposide. We also find that Top2α is the major isoform mediating the replication-dependent mechanism and both Top2α and Top2 mediate the transcription-dependent mechanism. These findings are potentially of great significance to the improvement of etoposide’s efficacy in cancer therapy. PMID:24244448

  4. Replication-dependent and transcription-dependent mechanisms of DNA double-strand break induction by the topoisomerase 2-targeting drug etoposide.

    PubMed

    Tammaro, Margaret; Barr, Peri; Ricci, Brett; Yan, Hong

    2013-01-01

    Etoposide is a DNA topoisomerase 2-targeting drug widely used for the treatment of cancer. The cytoxicity of etoposide correlates with the generation of DNA double-strand breaks (DSBs), but the mechanism of how it induces DSBs in cells is still poorly understood. Catalytically, etoposide inhibits the re-ligation reaction of Top2 after it nicks the two strands of DNA, trapping it in a cleavable complex consisting of two Top2 subunits covalently linked to the 5' ends of DNA (Top2cc). Top2cc is not directly recognized as a true DSB by cells because the two subunits interact strongly with each other to hold the two ends of DNA together. In this study we have investigated the cellular mechanisms that convert Top2ccs into true DSBs. Our data suggest that there are two mechanisms, one dependent on active replication and the other dependent on proteolysis and transcription. The relative contribution of each mechanism is affected by the concentration of etoposide. We also find that Top2α is the major isoform mediating the replication-dependent mechanism and both Top2α and Top2 mediate the transcription-dependent mechanism. These findings are potentially of great significance to the improvement of etoposide's efficacy in cancer therapy.

  5. Spectrum sharing in cognitive radio networks--an auction-based approach.

    PubMed

    Wang, Xinbing; Li, Zheng; Xu, Pengchao; Xu, Youyun; Gao, Xinbo; Chen, Hsiao-Hwa

    2010-06-01

    Cognitive radio is emerging as a promising technique to improve the utilization of the radio frequency spectrum. In this paper, we consider the problem of spectrum sharing among primary (or "licensed") users (PUs) and secondary (or "unlicensed") users (SUs). We formulate the problem based on bandwidth auction, in which each SU makes a bid for the amount of spectrum and each PU may assign the spectrum among the SUs by itself according to the information from the SUs without degrading its own performance. We show that the auction is a noncooperative game and that Nash equilibrium (NE) can be its solution. We first consider a single-PU network to investigate the existence and uniqueness of the NE and further discuss the fairness among the SUs under given conditions. Then, we present a dynamic updating algorithm in which each SU achieves NE in a distributed manner. The stability condition of the dynamic behavior for this spectrum-sharing scheme is studied. The discussion is generalized to the case in which there are multiple PUs in the network, where the properties of the NE are shown under appropriate conditions. Simulations were used to evaluate the system performance and verify the effectiveness of the proposed algorithm.

  6. Interaction of the tetracyclines with double-stranded RNAs of random base sequence: new perspectives on the target and mechanism of action.

    PubMed

    Chukwudi, Chinwe U; Good, Liam

    2016-08-01

    The 16S rRNA binding mechanism proposed for the antibacterial action of the tetracyclines does not explain their mechanism of action against non-bacterial pathogens. In addition, several contradictory base pairs have been proposed as their binding sites on the 16S rRNA. This study investigated the binding of minocycline and doxycycline to short double-stranded RNAs (dsRNAs) of random base sequences. These tetracyclines caused a dose-dependent decrease in the fluorescence intensities of 6-carboxyfluorescein (FAM)-labelled dsRNA and ethidium bromide (EtBr)-stained dsRNA, indicating that both drugs bind to dsRNA of random base sequence in a manner that is competitive with the binding of EtBr and other nucleic acid ligands often used as stains. This effect was observable in the presence of Mg(2+). The binding of the tetracyclines to dsRNA changed features of the fluorescence emission spectra of the drugs and the CD spectra of the RNA, and inhibited RNase III cleavage of the dsRNA. These results indicate that the double-stranded structures of RNAs may have a more important role in their interaction with the tetracyclines than the specific base pairs, which had hitherto been the subject of much investigation. Given the diverse functions of cellular RNAs, the binding of the tetracyclines to their double-stranded helixes may alter the normal processing and functioning of the various biological processes they regulate. This could help to explain the wide range of action of the tetracyclines against various pathogens and disease conditions.

  7. 78 FR 50086 - Notice of Competitive Auction for Solar Energy Development on Public Lands in the State of Colorado

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-16

    ... Bureau of Land Management Notice of Competitive Auction for Solar Energy Development on Public Lands in... applicant to submit a right-of-way (ROW) application and a plan of development for solar energy projects on... solicitations of interest and ROW applications within two designated Solar Energy Zones (SEZ): Los Mogotes...

  8. 76 FR 76174 - Request for Information on the State of the Offshore Renewable Energy Industry-Auction Format...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-06

    ... Bureau of Ocean Energy Management Request for Information on the State of the Offshore Renewable Energy... auction formats which may be used to issue commercial renewable energy leases on the Outer Continental... offshore renewable energy industry, including economic matters that promote or detract from...

  9. 31 CFR 356.4 - What are the book-entry systems in which auctioned Treasury securities may be issued?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... in which auctioned Treasury securities may be issued? There are three book-entry securities systems... marketable Treasury securities. We maintain and transfer securities in these three book-entry systems at... inflation. Securities may be transferred from one system to the other, unless the securities are...

  10. 47 CFR 27.1213 - Designated entity provisions for BRS in Commission auctions commencing prior to January 1, 2004.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Designated entity provisions for BRS in Commission auctions commencing prior to January 1, 2004. 27.1213 Section 27.1213 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS...

  11. 47 CFR 27.1213 - Designated entity provisions for BRS in Commission auctions commencing prior to January 1, 2004.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Designated entity provisions for BRS in Commission auctions commencing prior to January 1, 2004. 27.1213 Section 27.1213 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS...

  12. 47 CFR 27.1213 - Designated entity provisions for BRS in Commission auctions commencing prior to January 1, 2004.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Designated entity provisions for BRS in Commission auctions commencing prior to January 1, 2004. 27.1213 Section 27.1213 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS...

  13. 47 CFR 27.1213 - Designated entity provisions for BRS in Commission auctions commencing prior to January 1, 2004.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Designated entity provisions for BRS in Commission auctions commencing prior to January 1, 2004. 27.1213 Section 27.1213 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS...

  14. 30 CFR 285.308 - How will MMS conduct an auction for ROW grants and RUE grants?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... THE INTERIOR OFFSHORE RENEWABLE ENERGY ALTERNATE USES OF EXISTING FACILITIES ON THE OUTER CONTINENTAL SHELF Rights-of-Way Grants and Rights-of-Use and Easement Grants for Renewable Energy Activities... 30 Mineral Resources 2 2010-07-01 2010-07-01 false How will MMS conduct an auction for ROW...

  15. 75 FR 8703 - Auction of Lower and Upper Paging Bands Licenses Scheduled for May 25, 2010; Notice and Filing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-25

    ... bidding strategy, or the negotiation of settlement agreements. 14. The Commission remains vigilant about... with each other about bids, bidding strategies, or settlements unless such applicants have identified... strategy, which may include communications regarding the post-auction market structure. This...

  16. 76 FR 60830 - Auction of FM Broadcast Construction Permits Scheduled for March 27, 2012; Comment Sought on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-30

    .../cgb/ecfs/ . I. Introduction 1. The Wireless Telecommunications and Media Bureaus (the Bureaus... refer to AU Docket No. 11-146. The Wireless Telecommunications and Media Bureaus strongly encourage...: 202-418-0432. FOR FURTHER INFORMATION CONTACT: Wireless Telecommunications Bureau, Auctions...

  17. 81 FR 3465 - Notice of Realty Action: Proposed Competitive Sealed-Bid, Oral Auction Sale and Segregation of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2016-01-21

    ... Competitive Sealed-Bid, Oral Auction Sale and Segregation of Public Land in Owyhee County, ID AGENCY: Bureau... to offer a parcel of public land totaling 120.84 acres in Owyhee County, Idaho, by competitive sealed... sale is consistent with the 1999 Owyhee Resource Management Plan (RMP), Record of Decision,...

  18. Mechanism of adsorption of single and double stranded DNA on gold and silver nanoparticles: Investigating some important parameters in bio-sensing applications.

    PubMed

    Farkhari, Nahid; Abbasian, Sara; Moshaii, Ahmad; Nikkhah, Maryam

    2016-12-01

    The mechanism of adsorption of single and double stranded DNAs on colloidal gold and silver nanoparticles has been studied by measuring the resistance of the nanoparticles, surrounded by various oligonucleotides, against salt induced aggregation. It is shown that both single and double stranded DNAs can be adsorbed on the metal nanoparticles and the adsorption strength is determined by the interaction between various bases of DNA and the nanoparticles. By changing the salt concentration, the difference between adsorption of various DNA strands on the nanoparticles can be specified. The results indicate that a key parameter in success of a sensing assay of DNA hybridization is the salt concentration which should be greater than a minimum threshold depending on the nanoparticles characteristics. We have also investigated the interaction mechanism between various DNA bases with the metal nanoparticles. For both gold and silver nanoparticles, adenine has the highest and thymine has the lowest attachment to the nanoparticles. From surface enhanced Raman spectroscopy (SERS) data of various bases in the presence of gold nanoparticles, the probable interaction points in the bases with the nanoparticles have been determined, which are mainly the nitrogen sites of these oligonucleotides.

  19. Double-Network Hydrogel with Tunable Mechanical Performance and Biocompatibility for the Fabrication of Stem Cells-Encapsulated Fibers and 3D Assemble

    PubMed Central

    Liang, Zhe; Liu, Chenguang; Li, Lili; Xu, Peidi; Luo, Guoan; Ding, Mingyu; Liang, Qionglin

    2016-01-01

    Fabrication of cell-encapsulated fibers could greatly contribute to tissue engineering and regenerative medicine. However, existing methods suffered from not only unavoidability of cell damaging conditions and/or sophisticated equipment, but also unavailability of proper materials to satisfy both mechanical and biological expectations. In this work, a simple method is proposed to prepare cell-encapsulated fibers with tunable mechanical strength and stretching behavior as well as diameter and microstructure. The hydrogel fibers are made from optimal combination of alginate and poly(N-iso-propylacrylamide)-poly(ethylene glycol), characteristics of double-network hydrogel, with enough stiffness and flexibility to create a variety of three dimensional structures like parallel helical and different knots without crack. Furthermore, such hydrogel fibers exhibit better compatibility as indicated by the viability, proliferation and expression of pluripotency markers of embryonic stem cells encapsulated after 4-day culture. The double-network hydrogel possesses specific quick responses to either of alginate lyase, EDTA or lower environmental temperature which facilitate the optional degradation of fibers or fibrous assemblies to release the cells encapsulated for subsequent assay or treatment. PMID:27628933

  20. Human remains sold to the highest bidder! A snapshot of the buying and selling of human skeletal remains on eBay, an Internet auction site.

    PubMed

    Huxley, Angie K; Finnegan, Michael

    2004-01-01

    Internet auction sites have become increasingly popular, with diverse items up for sale to the public worldwide. The purposes of this paper are to inform the forensic community that human skeletal remains, old and new, are for sale on the eBay internet auction site, and to advise forensic scientists that eBay does not use a forensic anthropologist to assess photographs of these materials. Over the last few years, this website was "surfed," with numerous auctions during this period. After contacting eBay by email, representatives responded that they adhere to Native American Grave Protection and Repatriation Act (NAGPRA) and that their website indicates that auctions must state that sale of human remains is for instructional purposes only. Based on the photographs, the remains appear to be of prehistoric and modern origin. An unfortunate consequence of such sale may generate interest in stealing remains from graves, mortuaries, hospitals, or county morgues worldwide.

  1. Defects and Charge Trapping Mechanisms of Double Active Layer In-Zn-O and Al-Sn-Zn-In-O Thin-Film Transistors.

    PubMed

    Goh, Youngin; Kim, Taeho; Yang, Jong-Heon; Choi, Ji-Hun; Hwang, Chi-Sun; Cho, Sung Haeng; Jeon, Sanghun

    2017-03-02

    Active matrix organic light-emitting diodes (AMOLED) are considered as a core component of next-generation display technology, which can be used for wearable and flexible devices. Reliable thin-film transistors (TFTs) with high mobility are required to drive AMOLEDs. Recently, amorphous oxide TFTs, owing to their high mobility, have been considered as excellent substitutes for driving AMOLEDs. However, the device instabilities of high-mobility oxide TFTs have remained a key issue to be used in production. In this letter, we present the charge trapping and device instability mechanisms of high-mobility oxide TFTs with double active layers, using In-Zn-O (IZO) and Al-doped Sn-Zn-In-O (ATZIO) with various interfacial IZO thicknesses (0-6nm). To this end, we employed microsecond fast I-V, single-pulse I-V, transient current, and discharging current analysis. These AC device characterization methodologies enable the extraction of various trap parameters and defect densities as well as the understanding of dynamic charge transport in double active-layer TFTs. The results show that the number of defect sites decreases with an increase in the interfacial IZO thickness. From these results, we conclude that the interfacial IZO layer plays a crucial role in minimizing the charge trapping in ATZIO TFTs.

  2. Effects of shot peening pressure, media type and double shot peening on the microstructure, mechanical and tribological properties of low-alloy steel

    NASA Astrophysics Data System (ADS)

    Quang Trung, Pham; Win Khun, Nay; Butler, David Lee

    2016-12-01

    The effects of different shot peening conditions such as pressure (from 68.9-551.6 kPa), media type (media S230 and S110) and double shot peening on the microstructure, mechanical and tribological properties of shot peened AISI 4340 low-alloy steels, were systematically investigated. Their surface topography, hardness and roughness were analyzed by scanning electron microscopy, a Vickers micro-hardness tester and surface profilometer, respectively, while the cross-sectional sub-surface structures of the as-received and shot peened samples were characterized by means of optical microscopy and nanoindentation. The tribological properties were determined by using a ball-on-disc micro-tribological tester. It was shown that shot peening pressure and media type had a significant effect on the surface roughness, hardness, microstructure, wear resistance and friction of the shot peened AISI 4340 steel samples. It also indicated that the double shot peening process was a promising treatment, not only to reduce the surface roughness of the material after undergoing the first shot peening process with large media and high intensity, but to improve the tribological properties of the shot peened material.

  3. Direct electron-impact mechanism of excitation of mercury monobromide in a double-pulse dielectric-barrier-discharge HgBr lamp

    NASA Astrophysics Data System (ADS)

    Datsyuk, V. V.; Izmailov, I. A.; Naumov, V. V.; Kochelap, V. A.

    2016-08-01

    In a nonequlibrium plasma of a gas-discharge HgBr lamp, the terminal electronic state of the HgBr(B-X) radiative transition with a peak wavelength of 502 nm remains populated for a relatively long time and is repeatedly excited to the B state in collisions with plasma electrons. This transfer of the HgBr molecules from the ground state X to the excited state B is the main mechanism of formation of the light-emitting molecules especially when the lamp is excited by double current pulses. According to our simulations, due to the electron-induced transitions between HgBr(X) and HgBr(B), the output characteristics of the DBD lamp operating in a double-pulse regime are better than those of the lamp operating in a single-pulse regime. In the considered case, the peak power is calculated to increase by a factor of about 2 and the lamp efficiency increases by about 50%.

  4. The Combinatorial Retention Auction Mechanism (CRAM): Integrating Monetary and Non-monetary Reenlistment Incentives

    DTIC Science & Technology

    2011-11-01

    the Navy can eliminate the waste associated with unwanted benefits, while at the same time empowering its members. 14. KEY WORDS...Sailors to choose only those benefits which suit them, the Navy can eliminate the waste associated with unwanted benefits, while at the same time...those benefits they value more than the cost to provide, the Navy can eliminate the waste associated with unwanted or undervalued benefits, while at the

  5. Using the Vickrey-Clarke-Groves Auction Mechanisms for Enhanced Bandwidth Allocation in Tactical Data Networks

    DTIC Science & Technology

    2008-01-01

    exchange. This work is sponsored by the U.S. Department of Defense. The Software Engineering Institute is a federally funded research and development... SOFTWARE ENGINEERING INSTITUTE MATERIAL IS FURNISHED ON AN "AS-IS" BASIS. CARNEGIE MELLON UNIVERSITY MAKES NO WARRANTIES OF ANY KIND, EITHER EXPRESSED OR...performance of Federal Government Contract Number FA8721-05-C-0003 with Carnegie Mellon University for the operation of the Software Engineering

  6. Integrating Monetary and Non-monetary Reenlistment Incentives Utilizing the Combinatorial Retention Auction Mechanism (CRAM)

    DTIC Science & Technology

    2008-12-01

    distributive justice and benefit satisfaction. 37 Ronald G. Ehrenberg and Robert S. Smith, Modern Labor Economics Theory and Public Policy, 10th...Boening et al., “Benefit Packages,” 521. 53 Van Boening et al., “Benefit Packages,” 522. 54 Ronald G. Ehrenberg and Robert S. Smith, Modern Labor...Warfare Incentives,” (MBA professional report, Naval Postgraduate School, 2007). Ehrenberg , Ronald G. and Robert S. Smith, Modern Labor Economics

  7. Analysis of interface formation mechanism in GaN double-polarity selective-area growth by metalorganic vapor phase epitaxy

    NASA Astrophysics Data System (ADS)

    Kuze, Kenta; Osumi, Noriyuki; Fujita, Yohei; Inoue, Yoku; Nakano, Takayuki

    2016-05-01

    The fabrication of quasi-phase-matching (QPM) crystals by selective-area growth on the two asymmetrically polar surfaces of GaN is examined. We attempted the fabrication of GaN-QPM crystals by one-time growth using a carbon mask. For GaN double-polarity selective-area growth (DP-SAG), we investigated the effect of varied nitriding times of the Al2O3 templates patterned with the carbon mask. We optimized the nitriding conditions for the DP-SAG process, and evaluated the substrate fabricated by the optimized DP-SAG process. In addition, we examined the interface formation mechanism of DP-GaN fabricated by GaN DP-SAG process. We determined that it is possible to fabricate DP-GaN with a sharp interface by optimizing the growth conditions.

  8. Analysis of 12C+12C Elastic and Inelastic Scatterings in the Framework of the Cluster Double Folding Model and Coupled-Channels Mechanism

    NASA Astrophysics Data System (ADS)

    Hassanain, M. A.

    2011-08-01

    A double folding cluster (DFC) model is proposed for the analysis of (12) C+(12) C elastic and inelastic scatterings. The DFC procedure is performed using the alpha-clusters structure of (12) C nucleus. Angular distributions of the (12) C+(12) C elastic and inelastic scatterings in the energy range 70.7-126 MeV were analyzed using the derived DFC potentials in the framework of the coupled-channels (CC) mechanism. Successful descriptions of the data are obtained over the full measured angular range without the need to normalize the DFC potentials. Furthermore, the deduced deformation length and the quadrupole deformation parameter are quite consistent with the corresponding electromagnetic measurements.

  9. Effects of information on young consumers' willingness to pay for genetically modified food: experimental auction analysis.

    PubMed

    Kajale, Dilip B; Becker, T C

    2014-01-01

    This study examines the effects of information on consumers' willingness to pay (WTP) for genetically modified food (GMF). We used Vickrey second price experimental auction method for elicitation of consumer WTP for GM potato chips and GM soya-chocolate bar. The sample used in this study was university students from Delhi, India. Four information formats (positive, negative, no information, and combined information about GM technology) were used for the examination. The results show that, when students received the combine information they were willing to pay around 17%-20% premium for GMF and when received the negative information they demanded around 22% discount for GMF. While the positive- and the no-information formats alone have no considerable effect on consumers' WTP for GMF. Overall, our findings suggest that while doing marketing of GMF in India, the best strategy is to provide combined information about GM technology.

  10. Scope and Mechanisms of Frustrated Lewis Pair Catalyzed Hydrogenation Reactions of Electron-Deficient C=C Double Bonds.

    PubMed

    Morozova, Varvara; Mayer, Peter; Berionni, Guillaume

    2015-11-23

    Several phosphonium and ammonium triarylborohydrides, which are intermediates in hydrogenation reactions catalyzed by frustrated Lewis pairs, were synthesized in high yield under mild conditions from triaryl boranes, ammonium or phosphonium halides, and triethylsilane. The kinetics and mechanisms of the reactions of these hydridoborate salts with benzhydrylium ions, iminium ions, quinone methides, and Michael acceptors were investigated, and their nucleophilicity was determined and compared with that of other hydride donors.

  11. Structure of a Eukaryotic RNase III Post-Cleavage Complex Reveals a Double- Ruler Mechanism for Substrate Selection

    PubMed Central

    Liang, Yu-He; Lavoie, Mathieu; Comeau, Marc-Andre; Elela, Sherif Abou; Ji, Xinhua

    2014-01-01

    SUMMARY RNase III represents a family of dsRNA-specific endoribonucleases required for RNA maturation and gene regulation. The mechanism of action has been well characterized for the bacterial enzyme, but is not clear for eukaryotic RNase IIIs. Here, we describe the structure of Saccharomyces cerevisiae RNase III (Rnt1p) post-cleavage complex and explain the basis of its affinity for RNA stems capped with an NGNN tetraloop. The structure shows specific interactions between a new structural motif located at the end of Rnt1p dsRNA-binding domain (dsRBD) and the guanine nucleotide in the second position of the loop. Strikingly, structural and biochemical analyses indicate that the dsRBD and N-terminal domain function as two rulers measuring the distance between the tetraloop and the cleavage site. This unusual mechanism of substrate selectivity represents an example of the evolution of substrate selectivity and provides a framework for understanding the mechanism of action of eukaryotic RNase IIIs. PMID:24703949

  12. Plastic mechanism of multi-pass double-roller clamping spinning for arc-shaped surface flange

    NASA Astrophysics Data System (ADS)

    Fan, Shuqin; Zhao, Shengdun; Zhang, Qi; Li, Yongyi

    2013-11-01

    Compared with the conventional single-roller spinning process, the double-roller clamping spinning(DRCS) process can effectively prevent the sheet metal surface wrinkling and improve the the production efficiency and the shape precision of final spun part. Based on ABAQUS/Explicit nonlinear finite element software, the finite element model of the multi-pass DRCS for the sheet metal is established, and the material model, the contact definition, the mesh generation, the loading trajectory and other key technical problems are solved. The simulations on the multi-pass DRCS of the ordinary Q235A steel cylindrical part with the arc-shaped surface flange are carried out. The effects of number of spinning passes on the production efficiency, the spinning moment, the shape error of the workpiece, and the wall thickness distribution of the final part are obtained. It is indicated definitely that with the increase of the number of spinning passes the geometrical precision of the spun part increases while the production efficiency reduces. Moreover, the variations of the spinning forces and the distributions of the stresses, strains, wall thickness during the multi-pass DRCS process are revealed. It is indicated that during the DRCS process the radical force is the largest, and the whole deformation area shows the tangential tensile strain and the radial compressive strain, while the thickness strain changes along the generatrix directions from the compressive strain on the outer edge of the flange to the tensile strain on the inner edge of the flange. Based on the G-CNC6135 NC lathe, the three-axis linkage computer-controlled experimental device for DRCS which is driven by the AC servo motor is developed. And then using the experimental device, the Q235A cylindrical parts with the arc-shape surface flange are formed by the DRCS. The simulation results of spun parts have good consistency with the experimental results, which verifies the feasibility of DRCS process and the

  13. Essays on empirical analysis of multi-unit auctions: Impacts of financial transmission rights on the restructured electricity industry

    NASA Astrophysics Data System (ADS)

    Zang, Hailing

    This dissertation uses recently developed empirical methodologies for the study of multi-unit auctions to test the impacts of Financial Transmission Rights (FTRs) on the competitiveness of restructured electricity markets. FTRs are a special type of financial option that hedge against volatility in the cost of transporting electricity over the grid. Policy makers seek to use the prices of FTRs as market signals to incentivize efficient investment and utilization of transmission capacity. However, prices will not send the correct signals if market participants strategically use FTRs. This dissertation uses data from the Texas electricity market to test whether the prices of FTRs are efficient to achieve such goals. The auctions studied are multi-unit, uniform-price, sealed-bid auctions. The first part of the dissertation studies the auctions on the spot market of the wholesale electricity industry. I derive structural empirical models to test theoretical predictions as to whether bidders fully internalize the effect of FTRs on profits into their bidding decisions. I find that bidders are learning as to how to optimally bid above marginal cost for their inframarginal capacities. The bidders also learn to bid to include FTRs into their profit maximization problem during the course of the first year. But starting from the second year, they deviated from optimal bidding that includes FTRs in the profit maximization problems. Counterfactual analysis show that the primary effect of FTRs on market outcomes is changing the level of prices rather than production efficiency. Finally, I find that in most months, the current allocations of FTRs are statistically equivalent to the optimal allocations. The second part of the dissertation studies the bidding behavior in the FTR auctions. I find that FTRs' strategic impact on the FTR purchasing behavior is significant for large bidders---firms exercising market power in the FTR auctions. Second, trader forecasts future FTR credit

  14. New mechanism of γ-H2AX generation: Surfactant-induced actin disruption causes deoxyribonuclease I translocation to the nucleus and forms DNA double-strand breaks.

    PubMed

    Zhao, Xiaoxu; Yang, Gang; Toyooka, Tatsushi; Ibuki, Yuko

    2015-12-01

    We previously showed that nonionic surfactants, nonylphenol polyethoxylates (NPEOs), induced phosphorylation of histone H2AX, forming γ-H2AX. In this study, we analyzed the mechanism of γ-H2AX generation by an NPEO with 15 ethylene oxide units (NPEO(15)). In MCF-7 breast carcinoma cells, NPEO(15) treatment induced γ-H2AX in a dose-dependent manner. EDTA and ZnCl2, two inhibitors of deoxyribonuclease I (DNase I), inhibited both the γ-H2AX and DNA double-strand breaks induced by NPEO(15). NPEO(15) disrupted filamentous actin and released free DNase I as detected by cell fractionation analysis. Based on immunofluorescence staining of DNase I and monitoring DNase I-GFP localization, DNase I was translocated from the cytosol to the nucleus of cells after treatment with NPEO(15). This translocation did not occur with the common DNA damage inducers ultraviolet B irradiation and hydrogen peroxide. Other surfactants, Tween 20, Triton X-100 and Nonidet P-40, also generated γ-H2AX. These results show that γ-H2AX induction by surfactants including NPEOs, occurs via a new mechanism involving release of free DNase I with actin disruption. This mechanism is distinct from the process of γ-H2AX generation caused by direct chemically induced DNA damage.

  15. Meiotic DNA double-strand breaks and chromosome asynapsis in mice are monitored by distinct HORMAD2-independent and -dependent mechanisms.

    PubMed

    Wojtasz, Lukasz; Cloutier, Jeffrey M; Baumann, Marek; Daniel, Katrin; Varga, János; Fu, Jun; Anastassiadis, Konstantinos; Stewart, A Francis; Reményi, Attila; Turner, James M A; Tóth, Attila

    2012-05-01

    Meiotic crossover formation involves the repair of programmed DNA double-strand breaks (DSBs) and synaptonemal complex (SC) formation. Completion of these processes must precede the meiotic divisions in order to avoid chromosome abnormalities in gametes. Enduring key questions in meiosis have been how meiotic progression and crossover formation are coordinated, whether inappropriate asynapsis is monitored, and whether asynapsis elicits prophase arrest via mechanisms that are distinct from the surveillance of unrepaired DNA DSBs. We disrupted the meiosis-specific mouse HORMAD2 (Hop1, Rev7, and Mad2 domain 2) protein, which preferentially associates with unsynapsed chromosome axes. We show that HORMAD2 is required for the accumulation of the checkpoint kinase ATR along unsynapsed axes, but not at DNA DSBs or on DNA DSB-associated chromatin loops. Consistent with the hypothesis that ATR activity on chromatin plays important roles in the quality control of meiotic prophase, HORMAD2 is required for the elimination of the asynaptic Spo11(-/-), but not the asynaptic and DSB repair-defective Dmc1(-/-) oocytes. Our observations strongly suggest that HORMAD2-dependent recruitment of ATR to unsynapsed chromosome axes constitutes a mechanism for the surveillance of asynapsis. Thus, we provide convincing evidence for the existence of a distinct asynapsis surveillance mechanism that safeguards the ploidy of the mammalian germline.

  16. Mechanism of Action of Sulforaphane as a Superoxide Radical Anion and Hydrogen Peroxide Scavenger by Double Hydrogen Transfer: A Model for Iron Superoxide Dismutase.

    PubMed

    Prasad, Ajit Kumar; Mishra, P C

    2015-06-25

    The mechanism of action of sulforaphane as a scavenger of superoxide radical anion (O2(•-)) and hydrogen peroxide (H2O2) was investigated using density functional theory (DFT) in both gas phase and aqueous media. Iron superoxide dismutase (Fe-SOD) involved in scavenging superoxide radical anion from biological media was modeled by a complex consisting of the ferric ion (Fe(3+)) attached to three histidine rings. Reactions related to scavenging of superoxide radical anion by sulforaphane were studied using DFT in the presence and absence of Fe-SOD represented by this model in both gas phase and aqueous media. The scavenging action of sulforaphane toward both superoxide radical anion and hydrogen peroxide was found to involve the unusual mechanism of double hydrogen transfer. It was found that sulforaphane alone, without Fe-SOD, cannot scavenge superoxide radical anion in gas phase or aqueous media efficiently as the corresponding reaction barriers are very high. However, in the presence of Fe-SOD represented by the above-mentioned model, the scavenging reactions become barrierless, and so sulforaphane scavenges superoxide radical anion by converting it to hydrogen peroxide efficiently. Further, sulforaphane was found to scavenge hydrogen peroxide also very efficiently by converting it into water. Thus, the mechanism of action of sulforaphane as an excellent antioxidant has been unravelled.

  17. Bioinspired design and assembly of layered double hydroxide/poly(vinyl alcohol) film with high mechanical performance.

    PubMed

    Shu, Yingqi; Yin, Penggang; Liang, Benliang; Wang, Hao; Guo, Lin

    2014-09-10

    Inspired by the hierarchical structure and excellent mechanical performance of nacre, LDH nanosheets with an appropriate aspect ratio to withstand significant loads and at the same time allow for rupture under the pull-out mode were synthesized as artificial building blocks for the fabrication of nacre-like films. Multilayered PVA/LDH films with a high tensile strength and ductility were prepared for the first time by bottom-up layer-by-layer assembly of pretreated LDH nanosheets and spin-coating of PVA. The weight fraction of inorganic LDH platelets in the hybrid PVA/LDH films (wp) was controlled by changing the concentration of PVA solution applied in the spin-coating process. The resulting films revealed that the PVA/LDH hybrid films were piled close together to form a well-defined stratified structure resembling the brick-and-mortar structure of natural nacre. In the hybrid films, the content of inorganic LDH platelets was comparable to the value in nacre, up to 96.9 wt %. It could be clearly seen that the mechanical performance of the as-prepared PVA/LDH films was greatly improved by increasing the rigid building-block LDHs. The tensile strength of the 2 wt % PVA/LDH hybrid film reached a value of 169.36 MPa, thus exceeding the strength of natural nacre and reaching 4 times that of a pure PVA film. Meanwhile, its elastic modulus was comparable to that of lamellar bone.

  18. Von Willebrand factor in patients on mechanical circulatory support - a double-edged sword between bleeding and thrombosis.

    PubMed

    Hudzik, Bartosz; Kaczmarski, Jacek; Pacholewicz, Jerzy; Zakliczynski, Michal; Gasior, Mariusz; Zembala, Marian

    2015-09-01

    Mechanical circulatory support (MCS) is an umbrella term describing the various technologies used in both short- and long-term management of patients with either end-stage chronic heart failure (HF) or acute HF. Most often, MCS has emerged as a bridge to transplantation, but more recently it is also used as a destination therapy. Mechanical circulatory support includes left ventricular assist device (LVAD) or bi-ventricular assist device (Bi-VAD). Currently, 2- to 3-year survival in carefully selected patients is much better than with medical therapy. However, MCS therapy is hampered by sometimes life-threatening complications including bleeding and device thrombosis. Von Willebrand factor (vWF) has two major functions in haemostasis. First, it plays a crucial role in platelet-subendothelium adhesion and platelet-platelet interactions (aggregation). Second, it is the carrier of factor VIII (FVIII) in plasma. Von Willebrand factor prolongs FVIII half-time by protecting it from proteolytic degradation. It delivers FVIII to the site of vascular injury thus enhancing haemostatic process. On one hand, high plasma levels of vWF have been associated with an increased risk of thrombosis. On the other, defects or deficiencies of vWF underlie the inherited von Willebrand disease or acquired von Willebrand syndrome. Here we review the pathophysiology of thrombosis and bleeding associated with vWF.

  19. A Good Beginning Makes a Good Market: The Effect of Different Market Opening Structures on Market Quality.

    PubMed

    Hinterleitner, Gernot; Leopold-Wildburger, Ulrike; Mestel, Roland; Palan, Stefan

    2015-01-01

    This paper deals with the market structure at the opening of the trading day and its influence on subsequent trading. We compare a single continuous double auction and two complement markets with different call auction designs as opening mechanisms in a unified experimental framework. The call auctions differ with respect to their levels of transparency. We find that a call auction not only improves market efficiency and liquidity at the beginning of the trading day when compared to the stand-alone continuous double auction, but also causes positive spillover effects on subsequent trading. Concerning the design of the opening call auction, we find no significant differences between the transparent and nontransparent specification with respect to opening prices and liquidity. In the course of subsequent continuous trading, however, market quality is slightly higher after a nontransparent call auction.

  20. A Good Beginning Makes a Good Market: The Effect of Different Market Opening Structures on Market Quality

    PubMed Central

    Hinterleitner, Gernot; Leopold-Wildburger, Ulrike; Mestel, Roland; Palan, Stefan

    2015-01-01

    This paper deals with the market structure at the opening of the trading day and its influence on subsequent trading. We compare a single continuous double auction and two complement markets with different call auction designs as opening mechanisms in a unified experimental framework. The call auctions differ with respect to their levels of transparency. We find that a call auction not only improves market efficiency and liquidity at the beginning of the trading day when compared to the stand-alone continuous double auction, but also causes positive spillover effects on subsequent trading. Concerning the design of the opening call auction, we find no significant differences between the transparent and nontransparent specification with respect to opening prices and liquidity. In the course of subsequent continuous trading, however, market quality is slightly higher after a nontransparent call auction. PMID:26351653

  1. Truthful Incentive Mechanisms for Social Cost Minimization in Mobile Crowdsourcing Systems.

    PubMed

    Duan, Zhuojun; Yan, Mingyuan; Cai, Zhipeng; Wang, Xiaoming; Han, Meng; Li, Yingshu

    2016-04-06

    With the emergence of new technologies, mobile devices are capable of undertaking computational and sensing tasks. A large number of users with these mobile devices promote the formation of the Mobile Crowdsourcing Systems (MCSs). Within a MCS, each mobile device can contribute to the crowdsourcing platform and get rewards from it. In order to achieve better performance, it is important to design a mechanism that can attract enough participants with mobile devices and then allocate the tasks among participants efficiently. In this paper, we are interested in the investigation of tasks allocation and price determination in MCSs. Two truthful auction mechanisms are proposed for different working patterns. A Vickrey-Clarke-Groves (VCG)-based auction mechanism is proposed to the continuous working pattern, and a suboptimal auction mechanism is introduced for the discontinuous working pattern. Further analysis shows that the proposed mechanisms have the properties of individual rationality and computational efficiencies. Experimental results suggest that both mechanisms guarantee all the mobile users bidding with their truthful values and the optimal maximal social cost can be achieved in the VCG-based auction mechanism.

  2. Truthful Incentive Mechanisms for Social Cost Minimization in Mobile Crowdsourcing Systems

    PubMed Central

    Duan, Zhuojun; Yan, Mingyuan; Cai, Zhipeng; Wang, Xiaoming; Han, Meng; Li, Yingshu

    2016-01-01

    With the emergence of new technologies, mobile devices are capable of undertaking computational and sensing tasks. A large number of users with these mobile devices promote the formation of the Mobile Crowdsourcing Systems (MCSs). Within a MCS, each mobile device can contribute to the crowdsourcing platform and get rewards from it. In order to achieve better performance, it is important to design a mechanism that can attract enough participants with mobile devices and then allocate the tasks among participants efficiently. In this paper, we are interested in the investigation of tasks allocation and price determination in MCSs. Two truthful auction mechanisms are proposed for different working patterns. A Vickrey–Clarke–Groves (VCG)-based auction mechanism is proposed to the continuous working pattern, and a suboptimal auction mechanism is introduced for the discontinuous working pattern. Further analysis shows that the proposed mechanisms have the properties of individual rationality and computational efficiencies. Experimental results suggest that both mechanisms guarantee all the mobile users bidding with their truthful values and the optimal maximal social cost can be achieved in the VCG-based auction mechanism. PMID:27058541

  3. MicroRNAs Form Triplexes with Double Stranded DNA at Sequence-Specific Binding Sites; a Eukaryotic Mechanism via which microRNAs Could Directly Alter Gene Expression.

    PubMed

    Paugh, Steven W; Coss, David R; Bao, Ju; Laudermilk, Lucas T; Grace, Christy R; Ferreira, Antonio M; Waddell, M Brett; Ridout, Granger; Naeve, Deanna; Leuze, Michael; LoCascio, Philip F; Panetta, John C; Wilkinson, Mark R; Pui, Ching-Hon; Naeve, Clayton W; Uberbacher, Edward C; Bonten, Erik J; Evans, William E

    2016-02-01

    MicroRNAs are important regulators of gene expression, acting primarily by binding to sequence-specific locations on already transcribed messenger RNAs (mRNA) and typically down-regulating their stability or translation. Recent studies indicate that microRNAs may also play a role in up-regulating mRNA transcription levels, although a definitive mechanism has not been established. Double-helical DNA is capable of forming triple-helical structures through Hoogsteen and reverse Hoogsteen interactions in the major groove of the duplex, and we show physical evidence (i.e., NMR, FRET, SPR) that purine or pyrimidine-rich microRNAs of appropriate length and sequence form triple-helical structures with purine-rich sequences of duplex DNA, and identify microRNA sequences that favor triplex formation. We developed an algorithm (Trident) to search genome-wide for potential triplex-forming sites and show that several mammalian and non-mammalian genomes are enriched for strong microRNA triplex binding sites. We show that those genes containing sequences favoring microRNA triplex formation are markedly enriched (3.3 fold, p<2.2 × 10(-16)) for genes whose expression is positively correlated with expression of microRNAs targeting triplex binding sequences. This work has thus revealed a new mechanism by which microRNAs could interact with gene promoter regions to modify gene transcription.

  4. MicroRNAs form triplexes with double stranded DNA at sequence-specific binding sites; a eukaryotic mechanism via which microRNAs could directly alter gene expression

    SciTech Connect

    Paugh, Steven W.; Coss, David R.; Bao, Ju; Laudermilk, Lucas T.; Grace, Christy R.; Ferreira, Antonio M.; Waddell, M. Brett; Ridout, Granger; Naeve, Deanna; Leuze, Michael Rex; LoCascio, Philip F.; Panetta, John C.; Wilkinson, Mark R.; Pui, Ching -Hon; Naeve, Clayton W.; Uberbacher, Edward C.; Bonten, Erik J.; Evans, William E.

    2016-02-04

    MicroRNAs are important regulators of gene expression, acting primarily by binding to sequence-specific locations on already transcribed messenger RNAs (mRNA). Recent studies indicate that microRNAs may also play a role in up-regulating mRNA transcription levels, although a definitive mechanism has not been established. Double-helical DNA is capable of forming triple-helical structures through Hoogsteen and reverse Hoogsteen interactions in the major groove of the duplex, and we show physical evidence that microRNAs form triple-helical structures with duplex DNA, and identify microRNA sequences that favor triplex formation. We developed an algorithm (Trident) to search genome-wide for potential triplex-forming sites and show that several mammalian and non-mammalian genomes are enriched for strong microRNA triplex binding sites. We show that those genes containing sequences favoring microRNA triplex formation are markedly enriched (3.3 fold, p<2.2 x 10-16) for genes whose expression is positively correlated with expression of microRNAs targeting triplex binding sequences. As a result, this work has thus revealed a new mechanism by which microRNAs can interact with gene promoter regions to modify gene transcription.

  5. MicroRNAs form triplexes with double stranded DNA at sequence-specific binding sites; a eukaryotic mechanism via which microRNAs could directly alter gene expression

    DOE PAGES

    Paugh, Steven W.; Coss, David R.; Bao, Ju; ...

    2016-02-04

    MicroRNAs are important regulators of gene expression, acting primarily by binding to sequence-specific locations on already transcribed messenger RNAs (mRNA). Recent studies indicate that microRNAs may also play a role in up-regulating mRNA transcription levels, although a definitive mechanism has not been established. Double-helical DNA is capable of forming triple-helical structures through Hoogsteen and reverse Hoogsteen interactions in the major groove of the duplex, and we show physical evidence that microRNAs form triple-helical structures with duplex DNA, and identify microRNA sequences that favor triplex formation. We developed an algorithm (Trident) to search genome-wide for potential triplex-forming sites and show thatmore » several mammalian and non-mammalian genomes are enriched for strong microRNA triplex binding sites. We show that those genes containing sequences favoring microRNA triplex formation are markedly enriched (3.3 fold, p<2.2 x 10-16) for genes whose expression is positively correlated with expression of microRNAs targeting triplex binding sequences. As a result, this work has thus revealed a new mechanism by which microRNAs can interact with gene promoter regions to modify gene transcription.« less

  6. A mechanical property and stress corrosion evaluation of VIM-ESR-VAR work strengthened and direct double aged Inconel 718 bar material

    NASA Technical Reports Server (NTRS)

    Montano, J. W.

    1986-01-01

    Presented are the mechanical properties and the stress corrosion resistance of triple melted vacuum induction melted (VIM), electro-slag remelted (ESR), and vacuum arc remelted (VAR), solution treated, work strengthened and direct double aged Inconel 718 alloy bars 4.00 in. (10.16) and 5.75 in. (14.60 cm) diameter. Tensile, charpy v-notched impact, and compact tension specimens were tested at ambient temperature in both the longitudinal and transverse directions. Longitudinal tensile and yield strengths in excess of 220 ksi (1516.85 MPa) and 200 ksi (1378.00 MPa) respectively, were realized at ambient temperature. Additional charpy impact and compact tension tests were performed at -100 F (-73 C). Longitudinal charpy impact strength equalled or exceeded 12.0 ft-lbs (16.3 Joules) at ambient and at -100 F(-73 C) while longitudinal compact (LC) tension fracture toughness strength remained above 79 ksi (86.80 MPa) at ambient and at -100 F(-73 C) temperatures. No failures occurred in the longitudinal or transverse tensile specimens stressed to 75 and 100 percent of their respective yield strengths and exposed to a salt fog environment for 180 days. Tensile tests performed after the stress corrosion test indicated no mechanical property degradation.

  7. A randomized, double-blind, placebo-controlled, cross-over study to evaluate analgesic activity of Terminalia chebula in healthy human volunteers using a mechanical pain model

    PubMed Central

    Pokuri, Venkata Kishan; Kumar, Chiranjeevi Uday; Pingali, Usharani

    2016-01-01

    Background and Aims: To evaluate analgesic activity and safety of single oral dose (1000 mg) of Terminalia chebula using a mechanical pain model in healthy human volunteers. Material and Methods: Twelve healthy volunteers were randomized to receive either single oral dose of 2 capsules of T. chebula 500 mg each or identical placebo capsules in a double-blinded manner. Mechanical pain was assessed using Ugo basile analgesy meter (Randall–Selitto test) before and 3 h after administration of test drug. The parameters evaluated were pain threshold force and time; pain tolerance force and time. A washout period of 1-week was given for crossover between active drug and placebo. Results: Terminalia chebula significantly increased the mean percentage change for pain threshold force and time, and pain tolerance force and time compared to placebo (P < 0.001). The mean percentage change for pain threshold force and time (20.8% and 21.0%) was increased more than that of pain tolerance force and time (13.4% and 13.4%). No adverse drug reaction was reported with either of the study medications during the study period. Conclusion: T. chebula significantly increased pain threshold and pain tolerance compared to placebo. Both the study medications were well tolerated. Further multiple dose studies may be needed to establish the analgesic efficacy of the drug in patients suffering from osteoarthritis, rheumatoid arthritis and other painful conditions. PMID:27625480

  8. MicroRNAs Form Triplexes with Double Stranded DNA at Sequence-Specific Binding Sites; a Eukaryotic Mechanism via which microRNAs Could Directly Alter Gene Expression

    PubMed Central

    Grace, Christy R.; Ferreira, Antonio M.; Waddell, M. Brett; Ridout, Granger; Naeve, Deanna; Leuze, Michael; LoCascio, Philip F.; Panetta, John C.; Wilkinson, Mark R.; Pui, Ching-Hon; Naeve, Clayton W.; Uberbacher, Edward C.; Bonten, Erik J.; Evans, William E.

    2016-01-01

    MicroRNAs are important regulators of gene expression, acting primarily by binding to sequence-specific locations on already transcribed messenger RNAs (mRNA) and typically down-regulating their stability or translation. Recent studies indicate that microRNAs may also play a role in up-regulating mRNA transcription levels, although a definitive mechanism has not been established. Double-helical DNA is capable of forming triple-helical structures through Hoogsteen and reverse Hoogsteen interactions in the major groove of the duplex, and we show physical evidence (i.e., NMR, FRET, SPR) that purine or pyrimidine-rich microRNAs of appropriate length and sequence form triple-helical structures with purine-rich sequences of duplex DNA, and identify microRNA sequences that favor triplex formation. We developed an algorithm (Trident) to search genome-wide for potential triplex-forming sites and show that several mammalian and non-mammalian genomes are enriched for strong microRNA triplex binding sites. We show that those genes containing sequences favoring microRNA triplex formation are markedly enriched (3.3 fold, p<2.2 × 10−16) for genes whose expression is positively correlated with expression of microRNAs targeting triplex binding sequences. This work has thus revealed a new mechanism by which microRNAs could interact with gene promoter regions to modify gene transcription. PMID:26844769

  9. Analysis, Evaluation and Improvement of Sequential Single-Item Auctions for the Cooperative Real-Time Allocation of Tasks

    DTIC Science & Technology

    2013-03-30

    eds., Distributed Autonomous Robotic Systems 7. Springer . 21– 30. Clearwater, S.; Costanza, R.; Dixon, M.; and Schroeder, B. 1996. Saving energy...rescue simulation domain: A short note. In Birk, A., and Coradeschi, S., eds., RoboCup-2001: Robot Soccer World Cup V, Lecture Notes in Computer Science... Springer . Nanjanath, M., and Gini, M. 2008. Repeated auctions for robust task execution by a robot team. Technical Report 08-032, University of

  10. Integrating Electronic Reverse Auctions into Defense Procurement: Exploratory Research on Opportunities, Issues, Processes, Risks, and Cultural Implications

    DTIC Science & Technology

    2009-12-18

    Journal of Global Information Management, 6(3), 39-46. Sashi, C.M., & O’Leary, B. (2002). The role of internet auctions in the expansion of B2B ...AFFARS Air Force Federal Acquisition Regulation Supplement B2B Business-to-business B2C Business-to-consumer CECOM United States Army...decade, the growth of information technology—specifically the internet —has fundamentally changed how consumers communicate and conduct business on a

  11. Beneficial effects of dark chocolate on exercise capacity in sedentary subjects: underlying mechanisms. A double blind, randomized, placebo controlled trial.

    PubMed

    Taub, Pam R; Ramirez-Sanchez, Israel; Patel, Minal; Higginbotham, Erin; Moreno-Ulloa, Aldo; Román-Pintos, Luis Miguel; Phillips, Paul; Perkins, Guy; Ceballos, Guillermo; Villarreal, Francisco

    2016-09-14

    In heart failure patients the consumption of (-)-epicatechin ((-)-Epi)-rich cocoa can restore skeletal muscle (SkM) mitochondrial structure and decrease biomarkers of oxidative stress. However, nothing is known about its effects on exercise capacity and underlying mechanisms in normal, sedentary subjects. Twenty normal, sedentary subjects (∼50 years old) were randomized to placebo or dark chocolate (DC) groups and consumed 20 g of the products for 3 months. Subjects underwent before and after treatment, bicycle ergometry to assess VO2 max and work, SkM biopsy to assess changes in mitochondrial density, function and oxidative stress and blood sampling to assess metabolic endpoints. Seventeen subjects completed the trial. In the DC group (n = 9), VO2 max increased (17% increase, p = 0.056) as well as maximum work (watts) achieved (p = 0.026) with no changes with placebo (n = 8). The DC group evidenced increases in HDL levels (p = 0.005) and decreased triglycerides (p = 0.07). With DC, SkM evidenced significant increases in protein levels for LKB1, AMPK and PGC1α and in their active forms (phosphorylated AMPK and LKB1) as well as in citrate synthase activity while no changes were observed in mitochondrial density. With DC, significant increases in SkM reduced glutathione levels and decreases in protein carbonylation were observed. Improvements in maximum work achieved and VO2 max may be due to DC activation of upstream control systems and enhancement of SkM mitochondria efficiency. Larger clinical studies are warranted to confirm these observations.

  12. Emerging double helical nanostructures.

    PubMed

    Zhao, Meng-Qiang; Zhang, Qiang; Tian, Gui-Li; Wei, Fei

    2014-08-21

    As one of the most important and land-mark structures found in nature, a double helix consists of two congruent single helices with the same axis or a translation along the axis. This double helical structure renders the deoxyribonucleic acid (DNA) the crucial biomolecule in evolution and metabolism. DNA-like double helical nanostructures are probably the most fantastic yet ubiquitous geometry at the nanoscale level, which are expected to exhibit exceptional and even rather different properties due to the unique organization of the two single helices and their synergistic effect. The organization of nanomaterials into double helical structures is an emerging hot topic for nanomaterials science due to their promising exceptional unique properties and applications. This review focuses on the state-of-the-art research progress for the fabrication of double-helical nanostructures based on 'bottom-up' and 'top-down' strategies. The relevant nanoscale, mesoscale, and macroscopic scale fabrication methods, as well as the properties of the double helical nanostructures are included. Critical perspectives are devoted to the synthesis principles and potential applications in this emerging research area. A multidisciplinary approach from the scope of nanoscience, physics, chemistry, materials, engineering, and other application areas is still required to the well-controlled and large-scale synthesis, mechanism, property, and application exploration of double helical nanostructures.

  13. A Double-Blind Randomized Clinical Trial Comparing the Effect of Neostigmine and Metoclopramide on Gastric Residual Volume of Mechanically Ventilated ICU Patients

    PubMed Central

    Gholipour Baradari, Afshin; Alipour, Abbas; Firouzian, Abolfazl; Moarab, Laleh; Emami Zeydi, Amir

    2016-01-01

    Background: In critically ill patients, enteral feeding through the nasogastric tube is the method of choice for nutritional support. Gastrointestinal feeding intolerance and disturbed gastric emptying are common challenges in these patients. The aim of this study was to compare the effect of Neostigmine and Metoclopramide on gastric residual volume (GRV) in mechanically ventilated ICU patients. Methods: In a double blind, randomized clinical trial, a total of 60 mechanically ventilated ICU patients with GRV >120 mL (3 hours after the last gavage), were randomly assigned into two groups A and B. At baseline and 6 hours later, patients in group A and B received intravenous infusion of neostigmine in a dose of 2.5 mg and metoclopramide in a dose of 10 mg in 100 ml of normal saline, within 30 minutes. Patients’ gastric residual volumes were evaluated before the beginning of the intervention, and 3, 6, 9 and 12 hours after the intervention. Results: After adjusting of other variables (Sex, BMI and ICU stay period) generalized estimating equation (GEE) model revealed that neostigmine treatment increased odds of GRV improvement compare to metoclopramide group (Estimate 1.291, OR= 0.3.64, 95% CI 1.07-12.34). However there is a statistically significant time trend (within-subject differences or time effect) regardless of treatment groups (P<0.001). The median time from intervention to GRV improvement was 6 hours (95% CI 3.75-8.25) and 9 hours (95% CI 7.38-10.17) in neostigmine and metoclopramide groups, respectively. This difference was statistically significant (P<0.05). Conclusion: It seems that neostigmine is more effective than metoclopramide in reducing GRV and improving gastric emptying in mechanically ventilated ICU patients without significant complication and this protocol may be effective on the tolerance of enteral feeding in ICU patients. Further well-designed randomized clinical trials are needed. PMID:28077899

  14. Identifying Oneself with the Face of Someone Else Impairs the Egocentered Visuo-spatial Mechanisms: A New Double Mirror Paradigm to Study Self–other Distinction and Interaction

    PubMed Central

    Thirioux, Bérangère; Wehrmann, Moritz; Langbour, Nicolas; Jaafari, Nematollah; Berthoz, Alain

    2016-01-01

    Looking at our face in a mirror is one of the strongest phenomenological experiences of the Self in which we need to identify the face as reflected in the mirror as belonging to us. Recent behavioral and neuroimaging studies reported that self-face identification not only relies upon visual-mnemonic representation of one’s own face but also upon continuous updating and integration of visuo-tactile signals. Therefore, bodily self-consciousness plays a major role in self-face identification, with respect to interplay between unisensory and multisensory processing. However, if previous studies demonstrated that the integration of multisensory body-related signals contributes to the visual processing of one’s own face, there is so far no data regarding how self-face identification, inversely, contributes to bodily self-consciousness. In the present study, we tested whether self–other face identification impacts either the egocentered or heterocentered visuo-spatial mechanisms that are core processes of bodily self-consciousness and sustain self–other distinction. For that, we developed a new paradigm, named “Double Mirror.” This paradigm, consisting of a semi-transparent double mirror and computer-controlled Light Emitting Diodes, elicits self–other face merging illusory effect in ecologically more valid conditions, i.e., when participants are physically facing each other and interacting. Self-face identification was manipulated by exposing pairs of participants to an Interpersonal Visual Stimulation in which the reflection of their faces merged in the mirror. Participants simultaneously performed visuo-spatial and mental own-body transformation tasks centered on their own face (egocentered) or the face of their partner (heterocentered) in the pre- and post-stimulation phase. We show that self–other face identification altered the egocentered visuo-spatial mechanisms. Heterocentered coding was preserved. Our data suggest that changes in self

  15. Identifying Oneself with the Face of Someone Else Impairs the Egocentered Visuo-spatial Mechanisms: A New Double Mirror Paradigm to Study Self-other Distinction and Interaction.

    PubMed

    Thirioux, Bérangère; Wehrmann, Moritz; Langbour, Nicolas; Jaafari, Nematollah; Berthoz, Alain

    2016-01-01

    Looking at our face in a mirror is one of the strongest phenomenological experiences of the Self in which we need to identify the face as reflected in the mirror as belonging to us. Recent behavioral and neuroimaging studies reported that self-face identification not only relies upon visual-mnemonic representation of one's own face but also upon continuous updating and integration of visuo-tactile signals. Therefore, bodily self-consciousness plays a major role in self-face identification, with respect to interplay between unisensory and multisensory processing. However, if previous studies demonstrated that the integration of multisensory body-related signals contributes to the visual processing of one's own face, there is so far no data regarding how self-face identification, inversely, contributes to bodily self-consciousness. In the present study, we tested whether self-other face identification impacts either the egocentered or heterocentered visuo-spatial mechanisms that are core processes of bodily self-consciousness and sustain self-other distinction. For that, we developed a new paradigm, named "Double Mirror." This paradigm, consisting of a semi-transparent double mirror and computer-controlled Light Emitting Diodes, elicits self-other face merging illusory effect in ecologically more valid conditions, i.e., when participants are physically facing each other and interacting. Self-face identification was manipulated by exposing pairs of participants to an Interpersonal Visual Stimulation in which the reflection of their faces merged in the mirror. Participants simultaneously performed visuo-spatial and mental own-body transformation tasks centered on their own face (egocentered) or the face of their partner (heterocentered) in the pre- and post-stimulation phase. We show that self-other face identification altered the egocentered visuo-spatial mechanisms. Heterocentered coding was preserved. Our data suggest that changes in self-face identification induced

  16. Neural control mechanisms of the pheromone-triggered programmed behavior in male silkmoths revealed by double-labeling of descending interneurons and a motor neuron.

    PubMed

    Wada, Satoshi; Kanzaki, Ryohei

    2005-04-04

    Male silkmoths, Bombyx mori, exhibit a characteristic zigzagging behavior consisting of straight-line walking, zigzagging turns, and looping. The timing for shifting the turning direction is synchronized to the sideways head movements controlled by neck motor neurons (NMNs) including a cervical ventral NMN (cv1-NMN). It has been suggested that this programmed behavior is instructed by two types of activity patterns descending from the brain and the thoracic ganglion: one is a phasic excitation and the other is a state-dependent activity similar to the flipflop in electric memory circuits. These activities are shown by certain descending interneurons contained in two subsets of DNs, Group-I and -II DNs. However, it is not yet well understood which DNs are directly related to instructing this behavior. In order to understand neural control mechanisms of this programmed behavior, we investigated the morphological relationship between these DNs and the cv1-NMN, which is an index of this programmed behavior. We applied a double-labeling technique combining backfilling of the cv1-NMN and intracellular staining of single DNs. 3D confocal images revealed overlapping regions between the Group-I, -II DNs and the cv1-NMN. Group-IIA and -IID, which showed typical flipflop activities, Group-IIC DNs, which showed phasic excitation, and Group-IB DNs, which showed long-lasting inhibition had many overlapping regions on the cv1-NMNs. Our results indicate that the programmed behavior is instructed by these types of DNs.

  17. The effects of double austenitization on the mechanical properties of a 0. 34C containing low-alloy Ni-Cr-Mo-V steel

    SciTech Connect

    Chang, E.; Chang, C.Y. . Dept. of Materials Science and Engineering); Liu, C.D. )

    1994-03-01

    This article considers five different microstructures of a tempered martensitic 0.34C, 3Ni-1.3Cr-0.4Mo-0.1V steel through various heat treatments, including double austenitization (DA) treatments, and how the impact toughnesses are influenced by microstructure. Of the four mechanisms considered to explain the beneficial effect of DA treatment, the roles of retained austenite, grain-boundary embrittlement by impurity segregation, and matrix flow stress are discounted. The 50 pct fracture appearance transition temperature (FATT) of this steel is found to be dependent on both the grain size and the carbide dissolution. The conventionally treated steel contains mainly platelike M[sub 3]C carbides. The DA treatment helps to dissolve VC carbides and coarsen and spheroidize M[sub 3]C carbides in favor of the precipitation of short rodlike M7C3 carbides with a lower aspect ratio. The improvement of impact toughness (upper shelf energy, ductile-to-brittle transition temperature (DBTT), and lower shelf energy) by DA treatment, explained in detail, is attributed to a change of this material's tensile and work-hardening behavior affected by a variation of carbide morphology.

  18. Multifunctional organic–inorganic hybrid nanoparticles and nanosheets based on chitosan derivative and layered double hydroxide: cellular uptake mechanism and application for topical ocular drug delivery

    PubMed Central

    Chi, Huibo; Gu, Yan; Xu, Tingting; Cao, Feng

    2017-01-01

    To study the cellular uptake mechanism of multifunctional organic–inorganic hybrid nanoparticles and nanosheets, new chitosan–glutathione–valine–valine-layered double hydroxide (CG-VV-LDH) nanosheets with active targeting to peptide transporter-1 (PepT-1) were prepared, characterized and further compared with CG-VV-LDH nanoparticles. Both organic–inorganic hybrid nanoparticles and nanosheets showed a sustained release in vitro and prolonged precorneal retention time in vivo, but CG-VV-LDH nanoparticles showed superior permeability in the isolated cornea of rabbits than CG-VV-LDH nanosheets. Furthermore, results of cellular uptake on human corneal epithelial primary cells (HCEpiC) and retinal pigment epithelial (ARPE-19) cells indicated that both clathrin-mediated endocytosis and active transport of PepT-1 are involved in the internalization of CG-VV-LDH nanoparticles and CG-VV-LDH nanosheets. In summary, the CG-VV-LDH nanoparticle may be a promising carrier as a topical ocular drug delivery system for the treatment of ocular diseases of mid-posterior segments, while the CG-VV-LDH nanosheet may be suitable for the treatment of ocular surface diseases. PMID:28280329

  19. The Structural Features of Thousands of T-DNA Insertion Sites Are Consistent with a Double-Strand Break Repair-Based Insertion Mechanism.

    PubMed

    Kleinboelting, Nils; Huep, Gunnar; Appelhagen, Ingo; Viehoever, Prisca; Li, Yong; Weisshaar, Bernd

    2015-11-02

    Transformation by Agrobacterium tumefaciens, an important tool in modern plant research, involves the integration of T-DNA initially present on a plasmid in agrobacteria into the genome of plant cells. The process of attachment of the agrobacteria to plant cells and the transport of T-DNA into the cell and further to the nucleus has been well described. However, the exact mechanism of integration into the host's DNA is still unclear, although several models have been proposed. During confirmation of T-DNA insertion alleles from the GABI-Kat collection of Arabidopsis thaliana mutants, we have generated about 34,000 sequences from the junctions between inserted T-DNA and adjacent genome regions. Here, we describe the evaluation of this dataset with regard to existing models for T-DNA integration. The results suggest that integration into the plant genome is mainly mediated by the endogenous plant DNA repair machinery. The observed integration events showed characteristics highly similar to those of repair sites of double-strand breaks with respect to microhomology and deletion sizes. In addition, we describe unexpected integration events, such as large deletions and inversions at the integration site that are relevant for correct interpretation of results from T-DNA insertion mutants in reverse genetics experiments.

  20. Large-scale fabrication of linear low density polyethylene/layered double hydroxides composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties

    NASA Astrophysics Data System (ADS)

    Xie, Jiazhuo; Zhang, Kun; Zhao, Qinghua; Wang, Qingguo; Xu, Jing

    2016-11-01

    Novel LDH intercalated with organic aliphatic long-chain anion was large-scale synthesized innovatively by high-energy ball milling in one pot. The linear low density polyethylene (LLDPE)/layered double hydroxides (LDH) composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties were fabricated by melt blending and blowing process. FT IR, XRD, SEM results show that LDH particles were dispersed uniformly in the LLDPE composite films. Particularly, LLDPE composite film with 1% LDH exhibited the optimal performance among all the composite films with a 60.36% enhancement in the water vapor barrier property and a 45.73 °C increase in the temperature of maximum mass loss rate compared with pure LLDPE film. Furthermore, the improved infrared absorbance (1180-914 cm-1) of LLDPE/LDH films revealed the significant enhancement of heat retention. Therefore, this study prompts the application of LLDPE/LDH films as agricultural films with superior heat retention.

  1. Electrophoretic mobility of semi-flexible double-stranded DNA in defect-controlled polymer networks: Mechanism investigation and role of structural parameters.

    PubMed

    Khairulina, Kateryna; Li, Xiang; Nishi, Kengo; Shibayama, Mitsuhiro; Chung, Ung-il; Sakai, Takamasa

    2015-06-21

    Our previous studies have reported an empirical model, which explains the electrophoretic mobility (μ) of double-stranded DNA (dsDNA) as a combination of a basic migration term (Rouse-like or reptation) and entropy loss term in polymer gels with ideal network structure. However, this case is of exception, considering a large amount of heterogeneity in the conventional polymer gels. In this study, we systematically tune the heterogeneity in the polymer gels and study the migration of dsDNA in these gels. Our experimental data well agree with the model found for ideal networks. The basic migration mechanism (Rouse-like or reptation) persists perfectly in the conventional heterogeneous polymer gel system, while the entropy loss term continuously changes with increase in the heterogeneity. Furthermore, we found that in the limit where dsDNA is shorter than dsDNA persistence length, the entropy loss term may be related to the collisional motions between DNA fragments and the cross-links.

  2. A numerical investigation of the convective systems in the vicinity of southern Taiwan associated with Typhoon Fanapi (2010): Formation mechanism of double rainfall peaks

    NASA Astrophysics Data System (ADS)

    Huang, Ching-Yuang; Wu, I.-Hsin; Feng, Lei

    2016-11-01

    The westbound Typhoon Fanapi (2010) brought 872 mm daily rainfall over the coastal plain in southern Taiwan, which is comparable to the extreme rainfall of 1080 mm over the southern Central Mountain Range (CMR). In this study, the Weather Research and Forecast model was used to investigate the formation mechanism of the two rainfall peaks and the associated dynamics of the convective systems in the vicinity of southern Taiwan. As the vortex that deflects somewhat southward near landfall moves over the CMR, the vortex slows down significantly during westward departure and induces strong near-coastal convergence at lower levels with the westerly to southwesterly outer flow. The associated intense latent heating of the near-coastal rainfall greatly contributes to positive potential vorticity (PV) with enhanced vorticity stretching near the convex eyewall when the vortex becomes more asymmetric and longitudinally elongated. The positive PV tendency near the coast is induced not only by vertical differential diabatic heating (DDH) but also by the longitudinal DDH mainly associated with positive vorticity tilting. The longitudinal DDH indeed dominates all other processes in the PV generation inside the eyewall further offshore, which is vital to the maintenance of the eyewall with the strong banded convergence and is special to typical intense cyclones over the open ocean. The formation of the double intense rainfall peaks cannot occur without a precise departing track near the southwest coast in association with the slowdown of the vortex core when the CMR height is significantly reduced or latent heating is deactivated after landfall.

  3. Nej1 recruits the Srs2 helicase to DNA double-strand breaks and supports repair by a single-strand annealing-like mechanism.

    PubMed

    Carter, Sidney D; Vigasová, Dana; Chen, Jiang; Chovanec, Miroslav; Aström, Stefan U

    2009-07-21

    Double-strand breaks (DSBs) represent the most severe DNA lesion a cell can suffer, as they pose the risk of inducing loss of genomic integrity and promote oncogenesis in mammals. Two pathways repair DSBs, nonhomologous end joining (NHEJ) and homologous recombination (HR). With respect to mechanism and genetic requirements, characterization of these pathways has revealed a large degree of functional separation between the two. Nej1 is a cell-type specific regulator essential to NHEJ in Saccharomyces cerevisiae. Srs2 is a DNA helicase with multiple roles in HR. In this study, we show that Nej1 physically interacts with Srs2. Furthermore, mutational analysis of Nej1 suggests that the interaction was strengthened by Dun1-dependent phosphorylation of Nej1 serines 297/298. Srs2 was previously shown to be recruited to replication forks, where it promotes translesion DNA synthesis. We demonstrate that Srs2 was also efficiently recruited to DSBs generated by the HO endonuclease. Additionally, efficient Srs2 recruitment to this DSB was dependent on Nej1, but independent of mechanisms facilitating Srs2 recruitment to replication forks. Functionally, both Nej1 and Srs2 were required for efficient repair of DSBs with 15-bp overhangs, a repair event reminiscent of a specific type of HR called single-strand annealing (SSA). Moreover, absence of Rad51 suppressed the SSA-defect in srs2 and nej1 strains. We suggest a model in which Nej1 recruits Srs2 to DSBs to promote NHEJ/SSA-like repair by dismantling inappropriately formed Rad51 nucleoprotein filaments. This unexpected link between NHEJ and HR components may represent cross-talk between DSB repair pathways to ensure efficient repair.

  4. Nej1 recruits the Srs2 helicase to DNA double-strand breaks and supports repair by a single-strand annealing-like mechanism

    PubMed Central

    Carter, Sidney D.; Vigašová, Dana; Chen, Jiang; Chovanec, Miroslav; Åström, Stefan U.

    2009-01-01

    Double-strand breaks (DSBs) represent the most severe DNA lesion a cell can suffer, as they pose the risk of inducing loss of genomic integrity and promote oncogenesis in mammals. Two pathways repair DSBs, nonhomologous end joining (NHEJ) and homologous recombination (HR). With respect to mechanism and genetic requirements, characterization of these pathways has revealed a large degree of functional separation between the two. Nej1 is a cell-type specific regulator essential to NHEJ in Saccharomyces cerevisiae. Srs2 is a DNA helicase with multiple roles in HR. In this study, we show that Nej1 physically interacts with Srs2. Furthermore, mutational analysis of Nej1 suggests that the interaction was strengthened by Dun1-dependent phosphorylation of Nej1 serines 297/298. Srs2 was previously shown to be recruited to replication forks, where it promotes translesion DNA synthesis. We demonstrate that Srs2 was also efficiently recruited to DSBs generated by the HO endonuclease. Additionally, efficient Srs2 recruitment to this DSB was dependent on Nej1, but independent of mechanisms facilitating Srs2 recruitment to replication forks. Functionally, both Nej1 and Srs2 were required for efficient repair of DSBs with 15-bp overhangs, a repair event reminiscent of a specific type of HR called single-strand annealing (SSA). Moreover, absence of Rad51 suppressed the SSA-defect in srs2 and nej1 strains. We suggest a model in which Nej1 recruits Srs2 to DSBs to promote NHEJ/SSA-like repair by dismantling inappropriately formed Rad51 nucleoprotein filaments. This unexpected link between NHEJ and HR components may represent cross-talk between DSB repair pathways to ensure efficient repair. PMID:19571008

  5. Reverse Auction: A Potential Strategy for Reduction of Pharmacological Therapy Cost

    PubMed Central

    Brandão, Sara Michelly Gonçalves; Issa, Victor Sarli; Ayub-Ferreira, Silvia Moreira; Storer, Samantha; Gonçalves, Bianca Gigliotti; Santos, Valter Garcia; Carvas Junior, Nelson; Guimarães, Guilherme Veiga; Bocchi, Edimar Alcides

    2015-01-01

    Background Polypharmacy is a significant economic burden. Objective We tested whether using reverse auction (RA) as compared with commercial pharmacy (CP) to purchase medicine results in lower pharmaceutical costs for heart failure (HF) and heart transplantation (HT) outpatients. Methods We compared the costs via RA versus CP in 808 HF and 147 HT patients followed from 2009 through 2011, and evaluated the influence of clinical and demographic variables on cost. Results The monthly cost per patient for HF drugs acquired via RA was $10.15 (IQ 3.51-40.22) versus $161.76 (IQ 86.05‑340.15) via CP; for HT, those costs were $393.08 (IQ 124.74-774.76) and $1,207.70 (IQ 604.48-2,499.97), respectively. Conclusion RA may reduce the cost of prescription drugs for HF and HT, potentially making HF treatment more accessible. Clinical characteristics can influence the cost and benefits of RA. RA may be a new health policy strategy to reduce costs of prescribed medications for HF and HT patients, reducing the economic burden of treatment. PMID:26200898

  6. Genetic relationships between temperament of calves at auction and carcass traits in Japanese Black cattle.

    PubMed

    Takeda, Kazuya; Uchida, Hiroshi; Inoue, Keiichi

    2017-04-12

    Correlations of calves' temperament with carcass traits were estimated to clarify the genetic relationships between them in Japanese Black cattle. The temperament records for 3128 calves during auction at a calf market were scored on a scale of 1 (calm) to 5 (nervous) as temperament score (TS), and the TS were divided into two groups (TSG): TS 1 and 2 comprised TSG 1, and 3 to 5 constituted TSG 2. Carcass data were obtained from 33 552 fattened cattle. A threshold animal model was used for analyzing the underlying liability for TSG, whereas a linear one was used for TS and carcass traits. The heritability estimates for TS and TSG were 0.12 and 0.11, respectively. On the other hand, moderate to high heritability estimates were obtained for carcass traits (0.40 to 0.68). The temperament scores were negatively correlated with carcass weight, rib thickness and subcutaneous fat thickness (-0.13 to -0.59). In contrast, weak to moderate positive correlations were found between the temperament scores and rib eye area or yield estimate (0.16 to 0.45). The temperament scores and beef marbling score had no correlation. These results showed that it is possible to improve temperament and carcass traits simultaneously.

  7. Game auction prices are not related to biodiversity contributions of southern African ungulates and large carnivores.

    PubMed

    Dalerum, Fredrik; Miranda, Maria

    2016-02-25

    There is an urgent need for human societies to become environmentally sustainable. Because public policy is largely driven by economic processes, quantifications of the relationship between market prices and environmental values can provide important information for developing strategies towards sustainability. Wildlife in southern Africa is often privately owned and traded at game auctions to be utilized for commercial purposes mostly related to tourism. This market offers an interesting opportunity to evaluate how market prices relate to biologically meaningful species characteristics. In this market, prices were not correlated with species contributions to either phylogenetic or functional diversity, and species contributions to phylogenetic or functional diversity did not influence the trends in prices over time for the past 20 years. Since this economic market did not seem to appreciate evolutionary or ecologically relevant characteristics, we question if the game tourism market may contribute towards biodiversity conservation in southern Africa. We suggest that market prices in general may have limited values as guides for directing conservation and environmental management. We further suggest that there is a need to evaluate what humans value in biological organisms, and how potentially necessary shifts in such values can be instigated.

  8. Estimating the impact of different cigarette package warning label policies: the auction method.

    PubMed

    Thrasher, James F; Rousu, Matthew C; Anaya-Ocampo, Rafael; Reynales-Shigematsu, Luz Myriam; Arillo-Santillán, Edna; Hernández-Avila, Mauricio

    2007-12-01

    The study estimated the reduction in demand associated with implementing cigarette package warning labels that contain imagery illustrating the consequences of smoking. The experimental auction method was used, wherein adult smokers in Mexico (n=89) placed separate bids on two packs of cigarettes: one with a text-only warning label and the other with a warning label that included text and a graphic image. Differences in the values attributed to each pack were assessed using t-tests and multivariate regression. The pack with the graphic image had a mean attributed value which was 17% lower ($3.21 pesos) than the pack with the text-only warning, and this difference remained statistically significant within subgroups defined by sociodemographics, amount of smoking, number of quit attempts, and levels of perceived smoking risks. In the multivariate model, the difference in attributed values was greater among females than males, but no such differences were found for other sociodemographic or smoking-related variables. The consistently lower value that smokers attributed to cigarette packages with the graphic warning label indicates that these labels are likely to reduce cigarette demand.

  9. Game auction prices are not related to biodiversity contributions of southern African ungulates and large carnivores

    NASA Astrophysics Data System (ADS)

    Dalerum, Fredrik; Miranda, Maria

    2016-02-01

    There is an urgent need for human societies to become environmentally sustainable. Because public policy is largely driven by economic processes, quantifications of the relationship between market prices and environmental values can provide important information for developing strategies towards sustainability. Wildlife in southern Africa is often privately owned and traded at game auctions to be utilized for commercial purposes mostly related to tourism. This market offers an interesting opportunity to evaluate how market prices relate to biologically meaningful species characteristics. In this market, prices were not correlated with species contributions to either phylogenetic or functional diversity, and species contributions to phylogenetic or functional diversity did not influence the trends in prices over time for the past 20 years. Since this economic market did not seem to appreciate evolutionary or ecologically relevant characteristics, we question if the game tourism market may contribute towards biodiversity conservation in southern Africa. We suggest that market prices in general may have limited values as guides for directing conservation and environmental management. We further suggest that there is a need to evaluate what humans value in biological organisms, and how potentially necessary shifts in such values can be instigated.

  10. Game auction prices are not related to biodiversity contributions of southern African ungulates and large carnivores

    PubMed Central

    Dalerum, Fredrik; Miranda, Maria

    2016-01-01

    There is an urgent need for human societies to become environmentally sustainable. Because public policy is largely driven by economic processes, quantifications of the relationship between market prices and environmental values can provide important information for developing strategies towards sustainability. Wildlife in southern Africa is often privately owned and traded at game auctions to be utilized for commercial purposes mostly related to tourism. This market offers an interesting opportunity to evaluate how market prices relate to biologically meaningful species characteristics. In this market, prices were not correlated with species contributions to either phylogenetic or functional diversity, and species contributions to phylogenetic or functional diversity did not influence the trends in prices over time for the past 20 years. Since this economic market did not seem to appreciate evolutionary or ecologically relevant characteristics, we question if the game tourism market may contribute towards biodiversity conservation in southern Africa. We suggest that market prices in general may have limited values as guides for directing conservation and environmental management. We further suggest that there is a need to evaluate what humans value in biological organisms, and how potentially necessary shifts in such values can be instigated. PMID:26911226

  11. [Double responses].

    PubMed

    Motté, G; Dinanian, S; Sebag, C; Drieu, L; Slama, M

    1995-12-01

    Double response is a rare electrocardiographic phenomenon requiring two atrioventricular conduction pathways with very different electrophysiological properties. Double ventricular responses are the usual manifestation: an atrial depolarisation (spontaneous or provoked, anticipated or not) is followed by a first ventricular response dependent on an accessory pathway or a rapid nodal pathway and then a second response resulting from sufficiently delayed transmission through a nodal pathway for the ventricles to have recovered their excitability when the second wave of activation reaches them. A simple curiosity when isolated and occurring under unusual conditions, particularly during electrophysiological investigation of the Wolff-Parkinson-White syndrome, the double response may initiate symptomatic non-reentrant junctional tachycardia when associated with nodal duality and repeating from atria in sinus rhythm. The functional incapacity and resistance to antiarrhythmic therapy may require referral for ablation of the slow pathway.

  12. Microscopic mechanism underlying double-state lasing in an InAs/GaAs quantum dot laser diode elucidated using coupled rate equations and the spontaneous emission recorded from a window structure.

    PubMed

    Lee, J M; Jeon, B H; Kim, J; Lee, D

    2015-12-14

    We investigated the microscopic mechanism underlying the double-state lasing behavior (simultaneous lasing at the ground state [GS] and excited state [ES]) in InAs/GaAs quantum dot (QD) laser diodes. The ES and GS lasing processes that contributed to double-state lasing were examined experimentally and theoretically. Experiments were conducted in which spontaneous emission from a window of a QD laser diode was examined under lasing conditions, and numerical simulations were performed using a coupled rate equation model of the QD microstates. The findings showed that, when carrier relaxation from the ES to the GS was sufficiently slow, double-state lasing occurred. Additionally, ES lasing was found to arise not from the QD group undergoing GS lasing, but rather from another QD group in which the states were lower in energy and outside of the homogeneous bandwidth.

  13. Analysis of Repair Mechanisms following an Induced Double-Strand Break Uncovers Recessive Deleterious Alleles in the Candida albicans Diploid Genome.

    PubMed

    Feri, Adeline; Loll-Krippleber, Raphaël; Commere, Pierre-Henri; Maufrais, Corinne; Sertour, Natacha; Schwartz, Katja; Sherlock, Gavin; Bougnoux, Marie-Elisabeth; d'Enfert, Christophe; Legrand, Mélanie

    2016-10-11

    The diploid genome of the yeast Candida albicans is highly plastic, exhibiting frequent loss-of-heterozygosity (LOH) events. To provide a deeper understanding of the mechanisms leading to LOH, we investigated the repair of a unique DNA double-strand break (DSB) in the laboratory C. albicans SC5314 strain using the I-SceI meganuclease. Upon I-SceI induction, we detected a strong increase in the frequency of LOH events at an I-SceI target locus positioned on chromosome 4 (Chr4), including events spreading from this locus to the proximal telomere. Characterization of the repair events by single nucleotide polymorphism (SNP) typing and whole-genome sequencing revealed a predominance of gene conversions, but we also observed mitotic crossover or break-induced replication events, as well as combinations of independent events. Importantly, progeny that had undergone homozygosis of part or all of Chr4 haplotype B (Chr4B) were inviable. Mining of genome sequencing data for 155 C. albicans isolates allowed the identification of a recessive lethal allele in the GPI16 gene on Chr4B unique to C. albicans strain SC5314 which is responsible for this inviability. Additional recessive lethal or deleterious alleles were identified in the genomes of strain SC5314 and two clinical isolates. Our results demonstrate that recessive lethal alleles in the genomes of C. albicans isolates prevent the occurrence of specific extended LOH events. While these and other recessive lethal and deleterious alleles are likely to accumulate in C. albicans due to clonal reproduction, their occurrence may in turn promote the maintenance of corresponding nondeleterious alleles and, consequently, heterozygosity in the C. albicans species.

  14. Benzo[a]pyrene increases DNA double strand break repair in vitro and in vivo: a possible mechanism for benzo[a]pyrene-induced toxicity.

    PubMed

    Tung, Emily W Y; Philbrook, Nicola A; Belanger, Christine L; Ansari, Saad; Winn, Louise M

    2014-01-15

    Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon and carcinogen that is released into the environment through natural and anthropogenic sources. BaP toxicity is dependent on its metabolism by cytochrome P450s to the reactive metabolite benzo[a]pyrene diol epoxide (BPDE), which is strongly associated with increased mutation frequency. BaP can also be metabolized to benzo[a]pyrene quinones that can undergo redox cycling and induce oxidative stress. The purpose of this study was to examine if BaP exposure induces DNA double strand breaks (DSBs) and subsequently activate DNA DSB repair pathways in the CHO 3-6 cell line and pKZ1 mouse model. In vitro assessment of homologous recombination (HR) showed significantly increased HR frequency following exposure to 10μM of BaP. In vivo evaluations of BaP-induced DNA DSB repair demonstrated positive staining for intrachromosomal recombination events, which are associated with non-homologous end joining (NHEJ), in the lung and thymus of exposed animals that were statistically significant in the thymus when quantified by Western blotting. Gene expression analyses from mouse tissues showed significantly decreased expression of ATM and Xrcc6 in BaP-treated liver and lung. In addition, BaP exposure significantly reduced the expression of Xrcc5, p53, and DNA-PKcs in lung. Taken together, our results demonstrate that BaP increases DNA DSB repair in vitro and in vivo, and induces expression changes in DNA repair pathway genes. As repair of DNA DSBs is not error-free, aberrant DNA repair may be contributing to the mechanism of BaP-induced toxicity.

  15. Analysis of Repair Mechanisms following an Induced Double-Strand Break Uncovers Recessive Deleterious Alleles in the Candida albicans Diploid Genome

    PubMed Central

    Feri, Adeline; Loll-Krippleber, Raphaël; Commere, Pierre-Henri; Maufrais, Corinne; Sertour, Natacha; Schwartz, Katja; Sherlock, Gavin; Bougnoux, Marie-Elisabeth

    2016-01-01

    ABSTRACT The diploid genome of the yeast Candida albicans is highly plastic, exhibiting frequent loss-of-heterozygosity (LOH) events. To provide a deeper understanding of the mechanisms leading to LOH, we investigated the repair of a unique DNA double-strand break (DSB) in the laboratory C. albicans SC5314 strain using the I-SceI meganuclease. Upon I-SceI induction, we detected a strong increase in the frequency of LOH events at an I-SceI target locus positioned on chromosome 4 (Chr4), including events spreading from this locus to the proximal telomere. Characterization of the repair events by single nucleotide polymorphism (SNP) typing and whole-genome sequencing revealed a predominance of gene conversions, but we also observed mitotic crossover or break-induced replication events, as well as combinations of independent events. Importantly, progeny that had undergone homozygosis of part or all of Chr4 haplotype B (Chr4B) were inviable. Mining of genome sequencing data for 155 C. albicans isolates allowed the identification of a recessive lethal allele in the GPI16 gene on Chr4B unique to C. albicans strain SC5314 which is responsible for this inviability. Additional recessive lethal or deleterious alleles were identified in the genomes of strain SC5314 and two clinical isolates. Our results demonstrate that recessive lethal alleles in the genomes of C. albicans isolates prevent the occurrence of specific extended LOH events. While these and other recessive lethal and deleterious alleles are likely to accumulate in C. albicans due to clonal reproduction, their occurrence may in turn promote the maintenance of corresponding nondeleterious alleles and, consequently, heterozygosity in the C. albicans species. PMID:27729506

  16. Double-Base Binder Improvement

    DTIC Science & Technology

    The general objective of this program is to improve the mechanical properties of composite modified double base ( CMDB ) propellants, with particular emphasis upon those prepared by the slurry cast process.

  17. The loophole of the improved secure quantum sealed-bid auction with post-confirmation and solution

    NASA Astrophysics Data System (ADS)

    Luo, Yi; Zhao, Zhiwen; Zhao, Zhangji; Long, Haiming; Su, Wen; Yang, Yixian

    2013-01-01

    In the literature He et al. (Quantum Inf Process, 2011) performed the cryptanalysis about the protocol of secure quantum auction with post-confirmation, and proposed the melioration algorithm in order to defeat the collusion among some malicious bidders in Zhao et al.'s protocol (Zhao et al. in Opt Commun 283:3194, 2010). But unfortunately, this protocol can't defeat the collusion among some malicious bidders either. In this paper, we will analyze the security of He et al.'s protocol and point out the potential loophole. Furthermore, we propose an improved protocol which can defeat the collusion among malicious bidders effectively.

  18. Factors affecting the selling price of feeder cattle sold at Arkansas livestock auctions in 2005.

    PubMed

    Barham, B L; Troxel, T R

    2007-12-01

    Data were collected from 15 Arkansas livestock auctions to determine factors affecting selling price. Data included how calves were sold (single or groups), sex, breed or breed type, color, muscle thickness, horn status, frame score, fill, body condition, age, health, BW, and price. Data were randomly collected on 52,401 lots consisting of 105,542 calves. Selling prices for steers ($124.20 +/- 0.07), bulls ($117.93 +/- 0.12), and heifers ($112.81 +/- 0.07) were different from each other (P <0.001). Hereford x Charolais feeder calves sold for the highest price ($122.66 +/- 0.14) and Longhorns sold for the lowest price ($74.52 +/- 0.46). Yellow feeder cattle received the highest selling price ($96.47 +/- 0.12), and spotted or striped feeder cattle received the lowest price ($83.84 +/- 0.23). The selling price of singles was lower than the price for calves sold in groups of 6 or more ($117.26 +/- 0.06 vs. $122.61 +/- 0.21; P <0.001). For cattle classified as having muscle scores of 1, 2, 3, and 4, selling prices were $120.45 +/- 0.05, $111.31 +/- 0.09, $96.28 +/- 0.44, and $82.21 +/- 1.87, respectively. Polled feeder cattle sold for $118.57 +/- 0.05, and horned feeder cattle sold for $114.87 +/- 0.14 (P <0.001). Interactions (P <0.001) were detected between frame score and BW groups, and muscle score and BW groups on the selling price of cattle. A number of management and genetic factors affected the selling price of feeder cattle.

  19. Double Layers in Astrophysics

    NASA Technical Reports Server (NTRS)

    Williams, Alton C. (Editor); Moorehead, Tauna W. (Editor)

    1987-01-01

    Topics addressed include: laboratory double layers; ion-acoustic double layers; pumping potential wells; ion phase-space vortices; weak double layers; electric fields and double layers in plasmas; auroral double layers; double layer formation in a plasma; beamed emission from gamma-ray burst source; double layers and extragalactic jets; and electric potential between plasma sheet clouds.

  20. Bond-rearrangement and ionization mechanisms in the photo-double-ionization of simple hydrocarbons (C2H4 , C2H3F , and 1 ,1 -C2H2F2 ) near and above threshold

    NASA Astrophysics Data System (ADS)

    Gaire, B.; Gatton, A.; Wiegandt, F.; Neff, J.; Janke, C.; Zeller, S.; Reedy, D.; Rajput, J.; Ben-Itzhak, I.; Landers, A. L.; Belkacem, A.; Weber, Th.

    2016-09-01

    We investigate bond-rearrangement driven by photo-double-ionization (PDI) near and above the double-ionization threshold in a sequence of carbon-carbon double-bonded hydrocarbon molecules: ethylene, fluoroethylene, and 1,1-difluoroethylene. We employ the kinematically complete cold target recoil ion momentum spectroscopy method to resolve all photo-double-ionization events leading to two-ion fragments. We observe changes in the branching ratios of different dissociative ionization channels depending on the presence of no, one, or two fluorine atoms. The role of the fluorine atom in the bond-rearrangement channels is intriguing, as evident by the reordering of the threshold energies of the PDI in the fluorinated molecules. These effects offer a compelling argument that the electronegativity of the fluorine (or the polarity of the molecule) strongly influences the potential energy surfaces of the molecules and drives bond rearrangement during the dissociation process. The energy sharing and the relative angle between the three-dimensional momentum vectors of the two electrons enable us to distinguish between knockout and other ionization mechanisms of the PDI processes.

  1. Do I hear... anyone here? Tax-exempt healthcare facilities have taken a hit on auction-rate securities as the mortgage meltdown has investors skittish.

    PubMed

    Evans, Melanie

    2008-02-25

    The crisis in auction-rate securities is coming down hard on tax-exempt providers. Buyers are disappearing, sending interest rates soaring. Some hospitals and other healthcare borrowers are being forced to pay maximum interest. "Basically, the investor pool has all but vanished," says Melissa Williams, left, of Christus Health.

  2. 31 CFR 356.4 - What are the book-entry systems in which auctioned Treasury securities may be issued or maintained?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 2 2011-07-01 2011-07-01 false What are the book-entry systems in... BUREAU OF THE PUBLIC DEBT SALE AND ISSUE OF MARKETABLE BOOK-ENTRY TREASURY BILLS, NOTES, AND BONDS... book-entry systems in which auctioned Treasury securities may be issued or maintained? There are...

  3. A revealed preference approach to estimating supply curves for ecosystem services: use of auctions to set payments for soil erosion control in Indonesia.

    PubMed

    Jack, B Kelsey; Leimona, Beria; Ferraro, Paul J

    2009-04-01

    To supply ecosystem services, private landholders incur costs. Knowledge of these costs is critical for the design of conservation-payment programs. Estimating these costs accurately is difficult because the minimum acceptable payment to a potential supplier is private information. We describe how an auction of payment contracts can be designed to elicit this information during the design phase of a conservation-payment program. With an estimate of the ecosystem-service supply curve from a pilot auction, conservation planners can explore the financial, ecological, and socioeconomic consequences of alternative scaled-up programs. We demonstrate the potential of our approach in Indonesia, where soil erosion on coffee farms generates downstream ecological and economic costs. Bid data from a small-scale, uniform-price auction for soil-conservation contracts allowed estimates of the costs of a scaled-up program, the gain from integrating biophysical and economic data to target contracts, and the trade-offs between poverty alleviation and supply of ecosystem services. Our study illustrates an auction-based approach to revealing private information about the costs of supplying ecosystem services. Such information can improve the design of programs devised to protect and enhance ecosystem services.

  4. A Virtual Field Trip to the Real World of Cap and Trade: Environmental Economics and the EPA SO[subscript 2] Allowance Auction

    ERIC Educational Resources Information Center

    Lewis, Lynne Y.

    2011-01-01

    In the spring of 2001, Bates College Environmental Economics classes bought their first sulfur dioxide emissions allowance at U.S. Environmental Protection Agency's annual auction, then conducted by the Chicago Board of Trade. In the spring of 2010, they bought their 22nd through 34th allowances. This article describes a three-part method for…

  5. Usefulness of extracorporeal membrane oxygenation using double roller pumps in a low body weight newborn: A novel strategy for mechanical circulatory support in an infant.

    PubMed

    Nakanishi, Keisuke; Kato, Tomoko; Kawasaki, Shiori; Amano, Atsushi

    2016-01-01

    Extracorporeal membrane oxygenation (ECMO) with a centrifugal pump requires a certain flow rate; therefore, its application for low body weight infants is frequently accompanied by oxygenator membrane malfunction and/or inadequate perfusion. To prevent low-flow associated complications, we report a case in which a novel system of dual roller pumps was used. A baby girl with a body mass index 0.25 m(2), who experienced difficulty weaning from cardiopulmonary bypass after a Norwood-like operation, required an ECMO. Concerns for the tube lifespan reduction due to roller pump friction led to the use of a double roller pump circulation. The termination of ECMO during tube exchange is not needed, because circulation is maintained by another roller pump. The novel strategy of ECMO with double roller pumps will allow low perfusion rate to provide adequate circulatory support for low body weight patients.

  6. Measuring the Double Helix

    SciTech Connect

    Mathew-Fenn, R.S.; Das, R.; Harbury, P.A.B.

    2009-05-26

    DNA is thought to behave as a stiff elastic rod with respect to the ubiquitous mechanical deformations inherent to its biology. To test this model at short DNA lengths, we measured the mean and variance of end-to-end length for a series of DNA double helices in solution, using small-angle x-ray scattering interference between gold nanocrystal labels. In the absence of applied tension, DNA is at least one order of magnitude softer than measured by single-molecule stretching experiments. Further, the data rule out the conventional elastic rod model. The variance in end-to-end length follows a quadratic dependence on the number of base pairs rather than the expected linear dependence, indicating that DNA stretching is cooperative over more than two turns of the DNA double helix. Our observations support the idea of long-range allosteric communication through DNA structure.

  7. CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES: Operation Mechanism of Double-Walled Carbon Nanotubes Transistors Investigated By ab initio Calculations

    NASA Astrophysics Data System (ADS)

    Lan, Hai-Ping; Zhang, Shuang

    2009-11-01

    Recently, a new switching characteristic of double-walled carbon nanotubes (DWNTs) transistors is found in during experiments. We carry out a series of ab intio calculations on DWNTs' electronic properities, together with verification on the electronic response under the electric field. Our results reveal that the peculiar energy states relation in DWNTs and related contact modes should account for the distinct switching behavior of DWNT transistors. We believe these results have important implications in the fabrication and understanding of electronic devices with DWNTs.

  8. Controlled double-slit electron diffraction

    NASA Astrophysics Data System (ADS)

    Bach, Roger; Pope, Damian; Liou, Sy-Hwang; Batelaan, Herman

    2013-03-01

    Double-slit diffraction is a corner stone of quantum mechanics. It illustrates key features of quantum mechanics: interference and the particle-wave duality of matter. In 1965, Richard Feynman presented a thought experiment to show these features. Here we demonstrate the full realization of his famous thought experiment. By placing a movable mask in front of a double-slit to control the transmission through the individual slits, probability distributions for single- and double-slit arrangements were observed. Also, by recording single electron detection events diffracting through a double-slit, a diffraction pattern was built up from individual events.

  9. Seeing Double

    NASA Astrophysics Data System (ADS)

    Pesic, Peter

    2003-10-01

    The separateness and connection of individuals is perhaps the central question of human life: What, exactly, is my individuality? To what degree is it unique? To what degree can it be shared, and how? To the many philosophical and literary speculations about these topics over time, modern science has added the curious twist of quantum theory, which requires that the elementary particles of which everything consists have no individuality at all. All aspects of chemistry depend on this lack of individuality, as do many branches of physics. From where, then, does our individuality come? In Seeing Double, Peter Pesic invites readers to explore this intriguing set of questions. He draws on literary and historical examples that open the mind (from Homer to Martin Guerre to Kafka), philosophical analyses that have helped to make our thinking and speech more precise, and scientific work that has enabled us to characterize the phenomena of nature. Though he does not try to be all-inclusive, Pesic presents a broad range of ideas, building toward a specific point of view: that the crux of modern quantum theory is its clash with our ordinary concept of individuality. This represents a departure from the usual understanding of quantum theory. Pesic argues that what is bizarre about quantum theory becomes more intelligible as we reconsider what we mean by individuality and identity in ordinary experience. In turn, quantum identity opens a new perspective on us. Peter Pesic is a Tutor and Musician-in-Residence at St. John's College, Santa Fe, New Mexico. He has a Ph.D. in physics from Stanford University.

  10. Colloidal Double Quantum Dots

    PubMed Central

    2016-01-01

    Conspectus Pairs of coupled quantum dots with controlled coupling between the two potential wells serve as an extremely rich system, exhibiting a plethora of optical phenomena that do not exist in each of the isolated constituent dots. Over the past decade, coupled quantum systems have been under extensive study in the context of epitaxially grown quantum dots (QDs), but only a handful of examples have been reported with colloidal QDs. This is mostly due to the difficulties in controllably growing nanoparticles that encapsulate within them two dots separated by an energetic barrier via colloidal synthesis methods. Recent advances in colloidal synthesis methods have enabled the first clear demonstrations of colloidal double quantum dots and allowed for the first exploratory studies into their optical properties. Nevertheless, colloidal double QDs can offer an extended level of structural manipulation that allows not only for a broader range of materials to be used as compared with epitaxially grown counterparts but also for more complex control over the coupling mechanisms and coupling strength between two spatially separated quantum dots. The photophysics of these nanostructures is governed by the balance between two coupling mechanisms. The first is via dipole–dipole interactions between the two constituent components, leading to energy transfer between them. The second is associated with overlap of excited carrier wave functions, leading to charge transfer and multicarrier interactions between the two components. The magnitude of the coupling between the two subcomponents is determined by the detailed potential landscape within the nanocrystals (NCs). One of the hallmarks of double QDs is the observation of dual-color emission from a single nanoparticle, which allows for detailed spectroscopy of their properties down to the single particle level. Furthermore, rational design of the two coupled subsystems enables one to tune the emission statistics from single

  11. Colloidal Double Quantum Dots.

    PubMed

    Teitelboim, Ayelet; Meir, Noga; Kazes, Miri; Oron, Dan

    2016-05-17

    Pairs of coupled quantum dots with controlled coupling between the two potential wells serve as an extremely rich system, exhibiting a plethora of optical phenomena that do not exist in each of the isolated constituent dots. Over the past decade, coupled quantum systems have been under extensive study in the context of epitaxially grown quantum dots (QDs), but only a handful of examples have been reported with colloidal QDs. This is mostly due to the difficulties in controllably growing nanoparticles that encapsulate within them two dots separated by an energetic barrier via colloidal synthesis methods. Recent advances in colloidal synthesis methods have enabled the first clear demonstrations of colloidal double quantum dots and allowed for the first exploratory studies into their optical properties. Nevertheless, colloidal double QDs can offer an extended level of structural manipulation that allows not only for a broader range of materials to be used as compared with epitaxially grown counterparts but also for more complex control over the coupling mechanisms and coupling strength between two spatially separated quantum dots. The photophysics of these nanostructures is governed by the balance between two coupling mechanisms. The first is via dipole-dipole interactions between the two constituent components, leading to energy transfer between them. The second is associated with overlap of excited carrier wave functions, leading to charge transfer and multicarrier interactions between the two components. The magnitude of the coupling between the two subcomponents is determined by the detailed potential landscape within the nanocrystals (NCs). One of the hallmarks of double QDs is the observation of dual-color emission from a single nanoparticle, which allows for detailed spectroscopy of their properties down to the single particle level. Furthermore, rational design of the two coupled subsystems enables one to tune the emission statistics from single photon

  12. Double Your Major, Double Your Return?

    ERIC Educational Resources Information Center

    Del Rossi, Alison F.; Hersch, Joni

    2008-01-01

    We use the 2003 National Survey of College Graduates to provide the first estimates of the effect on earnings of having a double major. Overall, double majoring increases earnings by 2.3% relative to having a single major among college graduates without graduate degrees. Most of the gains from having a double major come from choosing fields across…

  13. Responses to the advanced notice of proposed rulemaking EPA published on June 6, 1996 regarding changes to the EPA allowance auctions and elimination of the direct sale

    SciTech Connect

    Critchfield, L.R.

    1997-12-31

    On June 6, 1996, EPA`s Acid Rain Program published an advance notice of proposed rulemaking (ANPRM) in the Federal Register seeking comment on: (1) whether to change the design of the annual sulfur dioxide (SO{sub 2}) allowance auctions; (2) whether to change the timing of the allowance auctions; (3) whether to change the requirement that the minimum price of offered allowances must be in whole dollars, and (4) whether EPA should propose the ability to submit allowance transfers electronically. EPA also published on that day a proposed and direct final rule on whether to eliminate the direct sale. This paper documents the issues addressed in the ANPRM, the comments EPA received, and EPA`s responses to those comments. EPA received comments from 14 separate commenters.

  14. Lubrication performance and mechanisms of Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxide nanoparticles as lubricant additives

    NASA Astrophysics Data System (ADS)

    Li, Shuo; Bhushan, Bharat

    2016-08-01

    Solid lubricant particles are commonly used as oil additives for low friction and wear. Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxides (LDH) were synthesized by coprecipitation method. The benefits of LDH nanoparticles are that they can be synthesized using chemical methods where size and shape can be controlled, and can be modified organically to allow dispersal in fluids. The LDH nanoparticles were characterized by X-ray diffraction, scanning electron microscope, thermogravimetry, and differential scanning calorimetry. A pin-on-disk friction and wear tester was used for evaluating the friction and wear properties of LDH nanoparticles as lubricant additives. LDH nanoparticles have friction-reducing and anti-wear properties compared to oil without LDHs. Mg/Al-LDH has the best lubrication, possibly due to better thermal stability in severe conditions.

  15. Estimating the impact of various menu labeling formats on parents' demand for fast-food kids' meals for their children: An experimental auction.

    PubMed

    Hobin, Erin; Lillico, Heather; Zuo, Fei; Sacco, Jocelyn; Rosella, Laura; Hammond, David

    2016-10-01

    This study experimentally tested whether parents' demand for fast-food kids' meals for their children is influenced by various menu labeling formats disclosing calorie and sodium information. The study also examined the effect of various menu labeling formats on parents' ability to identify fast-food kids' meals with higher calorie and sodium content. Online surveys were conducted among parents of children aged 3-12. Parents were randomized to view 1 of 5 menu conditions: 1) No Nutrition Information; 2) Calories-Only; 3) Calories + Contextual Statement (CS); 4) Calories, Sodium, + CS; and, 5) Calorie and Sodium in Traffic Lights + CS. Using an established experimental auction study design, parents viewed replicated McDonald's menus according to their assigned condition and were asked to bid on 4 Happy Meals. A randomly selected price was chosen; bids equal to or above this price "won" the auction, and bids less than this price "lost" the auction. After the auction, participants were asked to identify the Happy Meal with the highest calories and sodium content. Adjusting for multiple comparisons and covariates, the Calories, Sodium, + CS menu had a mean attributed value across all 4 Happy Meals which was 8% lower (-$0.31) than the Calories + CS menu (p < 0.05). Significantly more parents in the 4 menu conditions providing calories were able to correctly identify the Happy Meal with the highest calories (p < 0.0001) and significantly more parents in the 2 conditions providing sodium information were able to correctly identify the Happy Meal with the highest sodium content (p < 0.0001). Menus disclosing both calories and sodium information may reduce demand for fast-food kids' meals and better support parents in making more informed and healthier food choices for their children.

  16. Examining the relationship between psychosocial and behavioral proxies for future consumption behavior: self-reported impact and bidding behavior in an experimental auction study on cigarette labeling.

    PubMed

    Rousu, Matthew C; Thrasher, James F

    2014-04-01

    Experimental and observational research often involves asking consumers to self-report the impact of some proposed option. Because self-reported responses involve no consequence to the respondent for falsely revealing how he or she feels about an issue, self-reports may be subject to social desirability and other influences that bias responses in important ways. In this article, we analyzed data from an experiment on the impact of cigarette packaging and pack warnings, comparing smokers' self-reported impact (four-item scale) and the bids they placed in experimental auctions to estimate differences in demand. The results were consistent across methods; however, the estimated effect size associated with different warning labels was two times greater for the four-item self-reported response scale when compared to the change in demand as indicated by auction bids. Our study provides evidence that self-reported psychosocial responses provide a valid proxy for behavioral change as reflected by experimental auction bidding behavior. More research is needed to better understand the advantages and disadvantages of behavioral economic methods and traditional self-report approaches to evaluating health behavior change interventions.

  17. Examining the relationship between psychosocial and behavioral proxies for future consumption behavior: self-reported impact and bidding behavior in an experimental auction study on cigarette labeling

    PubMed Central

    Rousu, Matthew C.; Thrasher, James F.

    2014-01-01

    Experimental and observational research often involves asking consumers to self-report the impact of some proposed option. Because self-reported responses involve no consequence to the respondent for falsely revealing how he or she feels about an issue, self-reports may be subject to social desirability and other influences that bias responses in important ways. In this article, we analyzed data from an experiment on the impact of cigarette packaging and pack warnings, comparing smokers’ self-reported impact (four-item scale) and the bids they placed in experimental auctions to estimate differences in demand. The results were consistent across methods; however, the estimated effect size associated with different warning labels was two times greater for the four-item self-reported response scale when compared to the change in demand as indicated by auction bids. Our study provides evidence that self-reported psychosocial responses provide a valid proxy for behavioral change as reflected by experimental auction bidding behavior. More research is needed to better understand the advantages and disadvantages of behavioral economic methods and traditional self-report approaches to evaluating health behavior change interventions. PMID:24399267

  18. Monetary and Non-monetary SWO Retention Bonuses: An Experimental Approach to the Combinatorial Retention Auction Mechanism (CRAM)

    DTIC Science & Technology

    2009-12-01

    this illustration offer individual values that exceed the Navy’s cost to provide the incentive for most individuals. On the other hand, telecommuting ...cost effective for the Navy to offer geographic stability and homeport to these SWOs. At the same time, there are some SWOs that value telecommuting ...and sabbaticals more than it costs the Navy’s provide them. The Navy would omit a cost-effective incentive if it did not offer telecommuting and

  19. Auction Mechanisms For Allocating Individualized Non-monetary Retention Incentives in Complex Decision Environments: Evaluation Via Laboratory Experimentation

    DTIC Science & Technology

    2010-03-01

    Combined Learning Effects ...............87 b. Did Prior Experience With Similar Experiments Influence Results? ...........88 4. Hypothesis Tests...82 Figure 21. Learning Effect in Choosing the Optimal NMI Combinations – Additive Only....................83 Figure 22. Percent of...Observations with the Optimal NMI Combinations: Combinatorial NMI Values..........84 Figure 23. Learning Effect in Choosing the Optimal NMI Combinations

  20. Allocating Non-Monetary Incentives for Navy Nurse Corps Officers: Menu Method vs. Bid Method Combinatorial Retention Auction Mechanism (CRAM)

    DTIC Science & Technology

    2010-03-01

    Generation X and Y, and the Millennials ” all place distinctively different demands on employers based on their expectations. The “boomers’ make up the...majority of the professional nursing labor force and their exercising their options to retire at an increasing rate. Generation X, Y, and the Millennials ...must look at Firm B’s offer, which becomes the subject’s reservation wage , and then enter a salary request to Firm A. As previously discussed, if an

  1. Natural products: DNA double whammy

    NASA Astrophysics Data System (ADS)

    Gates, Kent S.

    2014-06-01

    The lomaiviticins are exceedingly potent antibiotic agents, but the mechanism responsible for this activity has so far been unclear. Now, efficient generation of double-strand breaks in DNA by lomaiviticin A has been linked to the remarkable cytotoxicity of these diazobenzofluorene-containg natural products.

  2. The double loop mattress suture

    PubMed Central

    Biddlestone, John; Samuel, Madan; Creagh, Terry; Ahmad, Tariq

    2014-01-01

    An interrupted stitch type with favorable tissue characteristics will reduce local wound complications. We describe a novel high-strength, low-tension repair for the interrupted closure of skin, cartilage, and muscle, the double loop mattress stitch, and compare it experimentally with other interrupted closure methods. The performance of the double loop mattress technique in porcine cartilage and skeletal muscle is compared with the simple, mattress, and loop mattress interrupted sutures in both a novel porcine loading chamber and mechanical model. Wound apposition is assessed by electron microscopy. The performance of the double loop mattress in vivo was confirmed using a series of 805 pediatric laparotomies/laparoscopies. The double loop mattress suture is 3.5 times stronger than the loop mattress in muscle and 1.6 times stronger in cartilage (p ≤ 0.001). Additionally, the double loop mattress reduces tissue tension by 66% compared with just 53% for the loop mattress (p ≤ 0.001). Wound gapping is equal, and wound eversion appears significantly improved (p ≤ 0.001) compared with the loop mattress in vitro. In vivo, the double loop mattress performs as well as the loop mattress and significantly better than the mattress stitch in assessments of wound eversion and dehiscence. There were no episodes of stitch extrusion in our series of patients. The mechanical advantage of its intrinsic pulley arrangement gives the double loop mattress its favorable properties. Wound dehiscence is reduced because this stitch type is stronger and exerts less tension on the tissue than the mattress stitch. We advocate the use of this novel stitch wherever a high-strength, low-tension repair is required. These properties will enhance wound repair, and its application will be useful to surgeons of all disciplines. PMID:24698436

  3. Stimulation targeting higher motor areas in stroke rehabilitation: A proof-of-concept, randomized, double-blinded placebo-controlled study of effectiveness and underlying mechanisms

    PubMed Central

    Cunningham, David A.; Varnerin, Nicole; Machado, Andre; Bonnett, Corin; Janini, Daniel; Roelle, Sarah; Potter-Baker, Kelsey; Sankarasubramanian, Vishwanath; Wang, Xiaofeng; Yue, Guang; Plow, Ela B.

    2016-01-01

    Purpose To demonstrate, in a proof-of-concept study, whether potentiating ipsilesional higher motor areas (premotor cortex and supplementary motor area) augments and accelerates recovery associated with constraint induced movement. Methods In a randomized, double-blinded pilot clinical study, 12 patients with chronic stroke were assigned to receive anodal transcranial direct current stimulation (tDCS) (n = 6) or sham (n = 6) to the ipsilesional higher motor areas during constraint-induced movement therapy. We assessed functional and neurophysiologic outcomes before and after 5 weeks of therapy. Results Only patients receiving tDCS demonstrated gains in function and dexterity. Gains were accompanied by an increase in excitability of the contralesional rather than the ipsilesional hemisphere. Conclusions Our proof-of-concept study provides early evidence that stimulating higher motor areas can help recruit the contralesional hemisphere in an adaptive role in cases of greater ipsilesional injury. Whether this early evidence of promise translates to remarkable gains in functional recovery compared to existing approaches of stimulation remains to be confirmed in large-scale clinical studies that can reasonably dissociate stimulation of higher motor areas from that of the traditional primary motor cortices. PMID:26484700

  4. Investigation of double bond conversion, mechanical properties, and antibacterial activity of dental resins with different alkyl chain length quaternary ammonium methacrylate monomers (QAM).

    PubMed

    He, Jingwei; Söderling, Eva; Vallittu, Pekka K; Lassila, Lippo V J

    2013-01-01

    In order to endow dental resin with antibacterial activity, a series of antibacterial quaternary ammonium methacrylate monomers (QAM) with different substituted alkyl chain length (from 10 to 18) were incorporated into commonly used 2,2-bis[4-(2'-hydroxy-3'-methacryloyloxy-propoxy)-phenyl]propane (Bis-GMA)/triethyleneglycol dimethacrylate (TEGDMA) (50 wt/50 wt) dental resin as immobilized antibacterial agents. Double bond conversion (DC), flexural strength (FS) and modulus (FM), and young and mature biofilms inhibition effectiveness of prepared dental resins were studied and Bis-GMA/TEGDMA without QAM was used as reference. Results showed that there was no significant difference on DC, FS, and FM between copolymer with and without 5 wt% QAM. Substituted alkyl chain length of QAM had no influence on DC, FS, and FM of copolymer, but had influence on antibacterial activity of copolymer. Antibacterial activity of copolymer increased with increasing of substituted alkyl chain length of QAM, and the sequence followed as 5%C10 < 5%C11 ≈ 5%C12 < 5%C16 ≈ 5%C18. Copolymers containing C18 and C16 had the best inhibition effectiveness on both young biofilm and mature biofilm, copolymers containing C12 and C11 only had inhibition effectiveness on young biofilm and copolymer containing C10 had none inhibition effectiveness on neither young biofilm nor mature biofilm.

  5. The roles of Dmrt (Double sex/Male-abnormal-3 Related Transcription factor) genes in sex determination and differentiation mechanisms: Ubiquity and diversity across the animal kingdom.

    PubMed

    Picard, Marion Anne-Lise; Cosseau, Céline; Mouahid, Gabriel; Duval, David; Grunau, Christoph; Toulza, Ève; Allienne, Jean-François; Boissier, Jérôme

    2015-07-01

    The Dmrt (Double sex/Male-abnormal-3 Related Transcription factor) genes have been intensively studied because they represent major transcription factors in the pathways governing sex determination and differentiation. These genes have been identified in animal groups ranging from cnidarians to mammals, and some of the genes functionally studied. Here, we propose to analyze (i) the presence/absence of various Dmrt gene groups in the different taxa across the animal kingdom; (ii) the relative expression levels of the Dmrt genes in each sex; (iii) the specific spatial (by organ) and temporal (by developmental stage) variations in gene expression. This review considers non-mammalian animals at all levels of study (i.e. no particular importance is given to animal models), and using all types of sexual strategy (hermaphroditic or gonochoric) and means of sex determination (i.e. genetic or environmental). To conclude this global comparison, we offer an analysis of the DM domains conserved among the different DMRT proteins, and propose a general sex-specific pattern for each member of the Dmrt gene family.

  6. Chromium (VI) and zinc (II) waste water co-treatment by forming layered double hydroxides: mechanism discussion via two different processes and application in real plating water.

    PubMed

    Zhang, Jia; Li, Yang; Zhou, Jizhi; Chen, Dan; Qian, Guangren

    2012-02-29

    Two processes, adsorption after synthesis (AAS) and adsorption during synthesis (ADS) were compared in CrO4(2-) and Zn2+/CrO4(2-) removal. Kinetic results showed that ADS was a better method than AAS, since Cr content was 0.65/0.81 mmol/g in Cr-ADS/ZnCr-ADS, but it was only 0.37/0.56 mmol/g in Cr-AAS/ZnCr-AAS. Then, a low-cost mixture was proposed to function as ADS raw materials in treating real plating waters. This mixture first got an isothermal saturation of 1.1 mmol/g in simulated CrO4(2-) water. When Zn2+ was co-treated, it was increased to 1.3 mmol/g. At the same time, a Zn2+ removal of 1.5 mmol/g was attained. Furthermore, real plating water co-treatment reached equilibrium in 6h and obtained 1.4/0.9 mmol/g for Zn2+/CrO4(2-), respectively. According to XRD analysis, this co-treatment enhancement resulted from the formation of Zn and Cr contained layered double hydroxide.

  7. Fabrication of mechanically robust, self-cleaning and optically high-performance hybrid thin films by SiO₂&TiO₂ double-shelled hollow nanospheres.

    PubMed

    Yao, Lin; He, Junhui; Geng, Zhi; Ren, Tingting

    2015-08-14

    Low-cost antireflection (AR) thin films on large-area optical surfaces are important for high-performance optical devices, display devices and photovoltaic cells. In the current work, SiO2&TiO2 double-shell hollow nanospheres (DSHNs) were designed, synthesized and utilized as building blocks for fabricating multifunctional AR thin films. By optimizing the porosity of SiO2&TiO2 DSHN and thin film structure, substrates with DSHN thin films attained transmittance as high as 99.4% and average transmittance up to 98.5% in the visible region. The nano-composite SiO2-TiO2 films exhibited intrinsic superhydrophilicity, anti-fogging and high photocatalytic activity. Tape peeling test, sponge washing test, and high temperature and moisture proof test showed favorable robustness and functional durability of the thin films, which make them extremely attractive for applications in lenses, photovoltaic cells and windows of high-rise buildings.

  8. Effect of amino acid dopants on the spectral, optical, mechanical and thermal properties of potassium acid phthalate crystals for possible optoelectronic and frequency doubling applications

    NASA Astrophysics Data System (ADS)

    Prakash, J. Thomas Joseph; Gnanaraj, J. Martin Sam; Dhavud, S. Shek; Ekadevasena, S.

    2015-09-01

    Undoped and amino acid (L-Arginine and L-Valine) doped KAP crystals were grown by slow evaporation solution growth technique. The changes in the structural, spectral, optical, mechanical and thermal properties were observed. The sharp prominent peaks in the indexed powder XRD pattern confirms the crystalline nature of the sample. Optical studies reveal that the crystal is transparent in the entire visible light region. Thermal stability was checked by TG/DTA analysis. The mechanical stability was evaluated from Vicker's microhardness test. The SHG efficiency for the title materials was tested with different particle sizes by the Kurtz and Perry powder method, which established the existence of phase matching.

  9. The effect of the mus309 mutation, defective in DNA double-strand break repair, on crossing over in Drosophila melanogaster suggests a mechanism for the centromere effect of crossing over.

    PubMed

    Portin, Petter

    2010-03-01

    The mus309 gene in Drosophila melanogaster encodes a RecQ helicase which is involved in DNA double-strand break (DSB) repair. In a brood pattern analysis, it was observed that in mus309 mutant females, the frequency of single crossovers in the central cv-v interval of the X chromosome was reduced in young females but returned to the level of the wild type control as the females aged. In the proximal v-f interval, the frequency of single crossovers was increased during the entire experimental period. In particular, it was observed that the frequency of double crossovers, as well as the coefficient of coincidence first increased but then gradually decreased, finally reaching the level of the control flies, as the females aged. Map distances increased due to the mus309 mutation in both gene interval studies, but they did not change as the females aged, a result suggesting that the mus309 gene controls the distribution of DSBs to be repaired as crossovers instead of non-crossovers. The results suggest a mechanism for the centromere effect of crossing over in Drosophila, viz the fact the frequency of meiotic crossing over reduces with the age of the female, and that the reduction is more pronounced the closer the interval is to the proximal heterochromatin of the chromosome arm. According to the model suggested, the centromere effect is simply a matter of the balance between different pathways of the repair of the DSBs of DNA.

  10. Gene expression suggests double-segmental and single-segmental patterning mechanisms during posterior segment addition in the beetle Tribolium castaneum.

    PubMed

    Janssen, Ralf

    2014-01-01

    In the model arthropod Drosophila, all segments are patterned simultaneously in the blastoderm. In most other arthropods, however, posterior segments are added sequentially from a posterior segment addition zone. Posterior addition of single segments likely represents the ancestral mode of arthropod segmentation, although in Drosophila, segments are patterned in pairs by the pair-rule genes. It has been shown that in the new model insect, the beetle Tribolium, a segmentation clock operates that apparently patterns all segments in pairs as well. Here, I report on the expression of the segment polarity gene H15/midline in Tribolium. In the anterior embryo, segmental stripes of H15 appear in pairs, but in the posterior of the embryo stripes appear in a single-segmental periodicity. This implies that either two completely different segmentation-mechanisms may act in the germ band of Tribolium, that the segmentation clock changes its periodicity during development, or that the speed in which posterior segments are patterned changes. In any case, the data suggest the presence of another (or modified), yet undiscovered, mechanism of posterior segment addition in one of the best-understood arthropod models. The finding of a hitherto unrecognized segmentation mechanism in Tribolium may have major implications for the understanding of the origin of segmentation mechanisms, including the origin of pair rule patterning. It also calls for (re)-investigation of posterior segment addition in Tribolium and other previously studied arthropod models.

  11. Double-Wall Carbon Nanotube Hybrid Mode-Locker in Tm-doped Fibre Laser: A Novel Mechanism for Robust Bound-State Solitons Generation

    NASA Astrophysics Data System (ADS)

    Chernysheva, Maria; Bednyakova, Anastasia; Al Araimi, Mohammed; Howe, Richard C. T.; Hu, Guohua; Hasan, Tawfique; Gambetta, Alessio; Galzerano, Gianluca; Rümmeli, Mark; Rozhin, Aleksey

    2017-03-01

    The complex nonlinear dynamics of mode-locked fibre lasers, including a broad variety of dissipative structures and self-organization effects, have drawn significant research interest. Around the 2 μm band, conventional saturable absorbers (SAs) possess small modulation depth and slow relaxation time and, therefore, are incapable of ensuring complex inter-pulse dynamics and bound-state soliton generation. We present observation of multi-soliton complex generation in mode-locked thulium (Tm)-doped fibre laser, using double-wall carbon nanotubes (DWNT-SA) and nonlinear polarisation evolution (NPE). The rigid structure of DWNTs ensures high modulation depth (64%), fast relaxation (1.25 ps) and high thermal damage threshold. This enables formation of 560-fs soliton pulses; two-soliton bound-state with 560 fs pulse duration and 1.37 ps separation; and singlet+doublet soliton structures with 1.8 ps duration and 6 ps separation. Numerical simulations based on the vectorial nonlinear Schr¨odinger equation demonstrate a transition from single-pulse to two-soliton bound-states generation. The results imply that DWNTs are an excellent SA for the formation of steady single- and multi-soliton structures around 2 μm region, which could not be supported by single-wall carbon nanotubes (SWNTs). The combination of the potential bandwidth resource around 2 μm with the soliton molecule concept for encoding two bits of data per clock period opens exciting opportunities for data-carrying capacity enhancement.

  12. Double-Wall Carbon Nanotube Hybrid Mode-Locker in Tm-doped Fibre Laser: A Novel Mechanism for Robust Bound-State Solitons Generation

    PubMed Central

    Chernysheva, Maria; Bednyakova, Anastasia; Al Araimi, Mohammed; Howe, Richard C. T.; Hu, Guohua; Hasan, Tawfique; Gambetta, Alessio; Galzerano, Gianluca; Rümmeli, Mark; Rozhin, Aleksey

    2017-01-01

    The complex nonlinear dynamics of mode-locked fibre lasers, including a broad variety of dissipative structures and self-organization effects, have drawn significant research interest. Around the 2 μm band, conventional saturable absorbers (SAs) possess small modulation depth and slow relaxation time and, therefore, are incapable of ensuring complex inter-pulse dynamics and bound-state soliton generation. We present observation of multi-soliton complex generation in mode-locked thulium (Tm)-doped fibre laser, using double-wall carbon nanotubes (DWNT-SA) and nonlinear polarisation evolution (NPE). The rigid structure of DWNTs ensures high modulation depth (64%), fast relaxation (1.25 ps) and high thermal damage threshold. This enables formation of 560-fs soliton pulses; two-soliton bound-state with 560 fs pulse duration and 1.37 ps separation; and singlet+doublet soliton structures with 1.8 ps duration and 6 ps separation. Numerical simulations based on the vectorial nonlinear Schr¨odinger equation demonstrate a transition from single-pulse to two-soliton bound-states generation. The results imply that DWNTs are an excellent SA for the formation of steady single- and multi-soliton structures around 2 μm region, which could not be supported by single-wall carbon nanotubes (SWNTs). The combination of the potential bandwidth resource around 2 μm with the soliton molecule concept for encoding two bits of data per clock period opens exciting opportunities for data-carrying capacity enhancement. PMID:28287159

  13. Nature and possible mechanisms of formation of potential mutations arising at emerging of thymine dimers after irradiation of double-stranded DNA by ultraviolet light

    NASA Astrophysics Data System (ADS)

    Grebneva, H. A.

    2003-01-01

    The mutagenesis under ultraviolet (UV)-irradiation is discussed. It is assumed, that the basic damages resulting in transitions, transversions, mutations of the frameshift and complex mutations are changes of the tautomeric state of the bases. The bases may be a part of dimers or may be not the dimer components. We consider such rare tautomeric states, which may influence the character of base pairing. A model of the formation of the above rare tautomeric forms of nucleotide bases under the UV-irradiation of the DNA is proposed. In the case of a radiation deexcitation of the DNA, which has absorbed the UV-quantum of the triplet energy level, there occur strong forced oscillations. They may result in changes of the lengths of hydrogen bonds between DNA bases. As a result, at H-bond shortening, the hydrogen atom may be almost in the center of H-bond. In the case of H-bond elongation, it may remain near the partner atom. Because of the H-bond breaking, during the formation of dimers, rare tautomeric forms of bases influencing the character of pairing can be realized. If a pair of the bases is not a part of dimer, then the only new stable configuration of the hydrogen atoms is the one that occurred at double-proton phototautomerism. It is shown that only those dimers are mutational, in which the change of a tautomeric state of the DNA bases have taken place. This is one of the differences between the proposed model and the standard one. The latter assumes, that from the point of view of ability of forming the mutations all the dimers are identical, and the DNA-polymerase is sometimes mistaken, incidentally building uncomplementary bases in. The consideration is only of qualitative character, it needs experimental verification, subsequent study by methods of quantum chemistry and theoretical physics. A list of problems to be studied in this respect is given.

  14. Double-Wall Carbon Nanotube Hybrid Mode-Locker in Tm-doped Fibre Laser: A Novel Mechanism for Robust Bound-State Solitons Generation.

    PubMed

    Chernysheva, Maria; Bednyakova, Anastasia; Al Araimi, Mohammed; Howe, Richard C T; Hu, Guohua; Hasan, Tawfique; Gambetta, Alessio; Galzerano, Gianluca; Rümmeli, Mark; Rozhin, Aleksey

    2017-03-13

    The complex nonlinear dynamics of mode-locked fibre lasers, including a broad variety of dissipative structures and self-organization effects, have drawn significant research interest. Around the 2 μm band, conventional saturable absorbers (SAs) possess small modulation depth and slow relaxation time and, therefore, are incapable of ensuring complex inter-pulse dynamics and bound-state soliton generation. We present observation of multi-soliton complex generation in mode-locked thulium (Tm)-doped fibre laser, using double-wall carbon nanotubes (DWNT-SA) and nonlinear polarisation evolution (NPE). The rigid structure of DWNTs ensures high modulation depth (64%), fast relaxation (1.25 ps) and high thermal damage threshold. This enables formation of 560-fs soliton pulses; two-soliton bound-state with 560 fs pulse duration and 1.37 ps separation; and singlet+doublet soliton structures with 1.8 ps duration and 6 ps separation. Numerical simulations based on the vectorial nonlinear Schr¨odinger equation demonstrate a transition from single-pulse to two-soliton bound-states generation. The results imply that DWNTs are an excellent SA for the formation of steady single- and multi-soliton structures around 2 μm region, which could not be supported by single-wall carbon nanotubes (SWNTs). The combination of the potential bandwidth resource around 2 μm with the soliton molecule concept for encoding two bits of data per clock period opens exciting opportunities for data-carrying capacity enhancement.

  15. Double-negative acoustic metamaterial.

    PubMed

    Li, Jensen; Chan, C T

    2004-11-01

    We show here the existence of acoustic metamaterial, in which both the effective density and bulk modulus are simultaneously negative, in the true and strict sense of an effective medium. Our double-negative acoustic system is an acoustic analogue of Veselago's medium in electromagnetism, and shares many unique consequences, such as negative refractive index. The double negativity in acoustics is derived from low-frequency resonances, as in the case of electromagnetism, but the negative density and modulus are derived from a single resonance structure as distinct from electromagnetism in which the negative permeability and negative permittivity originates from different resonance mechanisms.

  16. Molten Pool Behavior and Mechanical Properties of Pulsed Current Double-Sided Synchronization GTA Welded Fe-18Cr-17Mn-Ni-N

    NASA Astrophysics Data System (ADS)

    Qiang, Wei; Wang, Kehong; Feng, Yuehai; Chen, Jiahe

    2016-12-01

    Double-sided synchronization vertical gas tungsten arc welding (DSSVW) procedure was used to weld high-nitrogen low-nickel stainless steel Fe-18Cr-17Mn-Ni-N without groove and filler wire. First, the molten pool behaviors and appearances of pulsed current DSSVW (PC-DSSVW) and constant current DSSVW (CC-DSSVW) were comparatively analyzed. The periodic variation occurs in the width of both the anode region of the arc and the molten pool tail during PC-DSSVW, while the contact angle first increases and then decreases, and both the width of the anode region and the length of arc plume increase progressively in CC-DSSVW. It is found that the weld appearance of PC-DSSVW is superior to that of CC-DSSVW. Second, the forces of the DSSVW molten pool were analyzed. The result indicates that the molten pool of the DSSVW procedure is in a state of unstable equilibrium, and it will easily lose balance after being disturbed, resulting in the asymmetrical weld or hump bead. Third, the PC-DSSVW experiments at various welding speeds were conducted to study the influence of welding speed on the weld profile, microstructure, tensile strength and impact toughness. Furthermore, the solidification mode of Fe-18Cr-17Mn-Ni-N was predicted to help determine the microstructure of the welded joint. Results indicate that the weld width, weld reinforcement and melting area all increase with decreasing welding speed, and Fe-18Cr-17Mn-Ni-N solidifies as A mode. The microstructure of the base metal (BM) and heat-affected zone (HAZ) is equiaxed austenite and that of the fusion zone (FZ) is austenite dendrite with some chromium carbides dispersed in the grain boundary; with decreasing welding speed, grains become coarse. The maximum tensile strength (UTS) and elongation of PC-DSSVW joint are 860 MPa and 8.1%, and the elongation decreases dramatically with decreasing welding speed. The impact toughness decreases substantially compared to the BM, achieving 48.2% of the BM.

  17. Molten Pool Behavior and Mechanical Properties of Pulsed Current Double-Sided Synchronization GTA Welded Fe-18Cr-17Mn-Ni-N

    NASA Astrophysics Data System (ADS)

    Qiang, Wei; Wang, Kehong; Feng, Yuehai; Chen, Jiahe

    2017-02-01

    Double-sided synchronization vertical gas tungsten arc welding (DSSVW) procedure was used to weld high-nitrogen low-nickel stainless steel Fe-18Cr-17Mn-Ni-N without groove and filler wire. First, the molten pool behaviors and appearances of pulsed current DSSVW (PC-DSSVW) and constant current DSSVW (CC-DSSVW) were comparatively analyzed. The periodic variation occurs in the width of both the anode region of the arc and the molten pool tail during PC-DSSVW, while the contact angle first increases and then decreases, and both the width of the anode region and the length of arc plume increase progressively in CC-DSSVW. It is found that the weld appearance of PC-DSSVW is superior to that of CC-DSSVW. Second, the forces of the DSSVW molten pool were analyzed. The result indicates that the molten pool of the DSSVW procedure is in a state of unstable equilibrium, and it will easily lose balance after being disturbed, resulting in the asymmetrical weld or hump bead. Third, the PC-DSSVW experiments at various welding speeds were conducted to study the influence of welding speed on the weld profile, microstructure, tensile strength and impact toughness. Furthermore, the solidification mode of Fe-18Cr-17Mn-Ni-N was predicted to help determine the microstructure of the welded joint. Results indicate that the weld width, weld reinforcement and melting area all increase with decreasing welding speed, and Fe-18Cr-17Mn-Ni-N solidifies as A mode. The microstructure of the base metal (BM) and heat-affected zone (HAZ) is equiaxed austenite and that of the fusion zone (FZ) is austenite dendrite with some chromium carbides dispersed in the grain boundary; with decreasing welding speed, grains become coarse. The maximum tensile strength (UTS) and elongation of PC-DSSVW joint are 860 MPa and 8.1%, and the elongation decreases dramatically with decreasing welding speed. The impact toughness decreases substantially compared to the BM, achieving 48.2% of the BM.

  18. [The application of n-acetylcysteine as an antioxidant and mucolytic in mechanical ventilation in intensive care patients. A prospective, randomized, placebo-controlled, double-blind study].

    PubMed

    Konrad, F; Schoenberg, M H; Wiedmann, H; Kilian, J; Georgieff, M

    1995-09-01

    Oxygen radicals and oxygen radial mediators are thought to be important components in the development of acute lung injury, sepsis, and multiple organ failure. Injured patients, patients with pulmonary diseases, and multiple trauma patients also showed an elevated lipid peroxidation, indicating increased oxidant stress. N-Acetylcysteine (NAC) has been used as an antioxidant in a wide variety of experiments. NAC has been suggested to act by raising concentrations of cysteine, and hence glutathione, and by scavenging of oxidant species [1, 11, 17, 29]. The present study was designed to investigate whether the application of NAC in intubated patients has an effect on concentrations of reduced glutathione in plasma and bronchoalveolar lavage fluid (BAL) and on the lipid peroxidation products malondialdehyde and conjugated dienes. Because NAC has been widely used as a mucolytic drug for the treatment of lung diseases, the influence on tracheobronchial mucus was studied, too. METHODS. In a randomized, double-blind, placebo-controlled study, a total of 38 long-term ventilated patients of a surgical intensive care unit were investigated. Patients were treated for 5 days with either 3 g NAC/day or placebo. The plasma concentration of reduced glutathione, malondialdehyde, and conjugated dienes were measured on admission and on the 3rd and 5th days of treatment [8, 34, 48]. Additionally, the numbers of tracheobronchial suctionings were registered and chest radiographs were evaluated. A fibre-bronchoscopy was performed on admission and on the 3rd day of treatment. The amount and viscidity of tracheobronchial secretions were examined semiquantitatively, and glutathione levels were measured in the unconcentrated BAL. The study was approved by the ethics committee of the University of Ulm. RESULTS. The two groups were comparable with respect to age, sex, APACHE II score and diagnosis (Table 1). We found no significant differences in reduced glutathione levels in the plasma or in

  19. Double universality of a quantum phase transition in spinor condensates: modification of the Kibble-Żurek mechanism by a conservation law.

    PubMed

    Świsłocki, Tomasz; Witkowska, Emilia; Dziarmaga, Jacek; Matuszewski, Michał

    2013-01-25

    We consider a phase transition from an antiferromagnetic to a phase separated ground state in a spin-1 Bose-Einstein condensate of ultracold atoms. We demonstrate the occurrence of two scaling laws, for the number of spin domain seeds just after the phase transition, and for the number of spin domains in the final, stable configuration. Only the first scaling can be explained by the standard Kibble-Żurek mechanism. We explain the occurrence of two scaling laws by a model including postselection of spin domains due to the conservation of condensate magnetization.

  20. Ag/AgO Nanoparticles Grown via Time Dependent Double Mechanism in a 2D Layered Ni-PCP and Their Antibacterial Efficacy

    PubMed Central

    Agarwal, Rashmi A.; Gupta, Neeraj K.; Singh, Rajan; Nigam, Shivansh; Ateeq, Bushra

    2017-01-01

    A simple synthesis route for growth of Ag/AgO nanoparticles (NPs) in large quantitative yields with narrow size distribution from a functional, non-activated, Ni (II) based highly flexible porous coordination polymer (PCP) as a template has been demonstrated. This template is a stable storage media for the NPs larger than the pore diameters of the PCP. From EPR study it was concluded that NPs were synthesized via two mechanisms i.e. acid formation and the redox activity of the framework. Size range of Ag/AgO NPs is sensitive to choice of solvent and reaction time. Direct use of Ag/AgO@Ni-PCP shows influential growth inhibition towards Escherichia coli and the pathogen Salmonella typhimurium at extremely low concentrations. The pristine template shows no cytotoxic activity, even though it contains Ni nodes in the framework. PMID:28322256

  1. Ag/AgO Nanoparticles Grown via Time Dependent Double Mechanism in a 2D Layered Ni-PCP and Their Antibacterial Efficacy

    NASA Astrophysics Data System (ADS)

    Agarwal, Rashmi A.; Gupta, Neeraj K.; Singh, Rajan; Nigam, Shivansh; Ateeq, Bushra

    2017-03-01

    A simple synthesis route for growth of Ag/AgO nanoparticles (NPs) in large quantitative yields with narrow size distribution from a functional, non-activated, Ni (II) based highly flexible porous coordination polymer (PCP) as a template has been demonstrated. This template is a stable storage media for the NPs larger than the pore diameters of the PCP. From EPR study it was concluded that NPs were synthesized via two mechanisms i.e. acid formation and the redox activity of the framework. Size range of Ag/AgO NPs is sensitive to choice of solvent and reaction time. Direct use of Ag/AgO@Ni-PCP shows influential growth inhibition towards Escherichia coli and the pathogen Salmonella typhimurium at extremely low concentrations. The pristine template shows no cytotoxic activity, even though it contains Ni nodes in the framework.

  2. Distinct mechanisms for opposite functions of homeoproteins Cdx2 and HoxB7 in double-strand break DNA repair in colon cancer cells.

    PubMed

    Soret, Christine; Martin, Elisabeth; Duluc, Isabelle; Dantzer, Françoise; Vanier, Marie; Gross, Isabelle; Freund, Jean-Noël; Domon-Dell, Claire

    2016-05-01

    Homeobox genes, involved in embryonic development and tissues homeostasis in adults, are often deregulated in cancer, but their relevance in pathology is far from being fully elucidated. In colon cancers, we report that the homeoproteins HoxB7 and Cdx2 exhibit different heterogeneous patterns, Cdx2 being localized in moderately altered neoplasic glands in contrast to HoxB7 which predominates in poorly-differentiated areas; they are coexpressed in few cancer cells. In human colon cancer cells, both homeoproteins interact with the DNA repair factor KU70/80, but functional studies reveal opposite effects: HoxB7 stimulates DNA repair and cell survival upon etoposide treatment, whereas Cdx2 inhibits both processes. The stimulatory effect of HoxB7 on DNA repair requires the transactivation domain linked to the homeodomain involved in the interaction with KU70/80, whereas the transactivation domain of Cdx2 is dispensable for its inhibitory function, which instead needs the homeodomain to interact with KU70/80 and the C-terminal domain. Thus, HoxB7 and Cdx2 respectively use transcription-dependent and -independent mechanisms to stimulate and inhibit DNA repair. In addition, in cells co-expressing both homeoproteins, Cdx2 lessens DNA repair activity through a novel mechanism of inhibition of the transcriptional function of HoxB7, whereby Cdx2 forms a molecular complex with HoxB7 and prevents it to recognize its target in the chromatin. These results point out the complex interplay between the DSB DNA repair activity and the homeoproteins HoxB7 and Cdx2 in colon cancer cells, making the balance between these factors a determinant and a potential indicator of the efficacy of genotoxic drugs.

  3. [A double gallbladder].

    PubMed

    Mink van der Molen, A B; Salu, M K

    1991-04-06

    A 59-year-old woman is described with symptomatic cholelithiasis. A double gallbladder was incidentally found during abdominal surgery. The literature on a double gallbladder is reviewed with respect to incidence, anatomy, diagnosis and therapy.

  4. Pathways to doubled haploidy: chromosome doubling during androgenesis.

    PubMed

    Seguí-Simarro, J M; Nuez, F

    2008-01-01

    Production of doubled haploid (DH) plants through androgenesis induction is a promising and convenient alternative to conventional selfing techniques for the generation of pure lines for breeding programs. This process comprises two main steps: induction of androgenesis and duplication of the haploid genome. Such duplication is sometimes indirectly induced by the treatments used to promote androgenic development. But usually, an additional step of direct chromosome doubling must be included in the protocol. Duplication of the haploid genome of androgenic individuals has been thought to occur through three mechanisms: endoreduplication, nuclear fusion and c-mitosis. In this review we will revise and analyze the evidences supporting each of the proposed mechanisms and their relevance during androgenesis induction, embryo/callus development and plant regeneration. Special attention will be devoted to nuclear fusion, whose evidences are accumulating in the last years.

  5. Encouraging stormwater management using a reverse auction: potential to restore stream ecosystems

    EPA Science Inventory

    Stormwater runoff is the primary mechanism by which urbanizing landscapes disrupt natural, stream ecosystems. Source control management has been demonstrated as an effective and cost-efficient method for reducing stormwater runoff; however, sufficiently widespread implementation...

  6. Chromosome doubling method

    DOEpatents

    Kato, Akio

    2006-11-14

    The invention provides methods for chromosome doubling in plants. The technique overcomes the low yields of doubled progeny associated with the use of prior techniques for doubling chromosomes in plants such as grasses. The technique can be used in large scale applications and has been demonstrated to be highly effective in maize. Following treatment in accordance with the invention, plants remain amenable to self fertilization, thereby allowing the efficient isolation of doubled progeny plants.

  7. The double identity of linguistic doubling.

    PubMed

    Berent, Iris; Bat-El, Outi; Brentari, Diane; Dupuis, Amanda; Vaknin-Nusbaum, Vered

    2016-11-29

    Does knowledge of language consist of abstract principles, or is it fully embodied in the sensorimotor system? To address this question, we investigate the double identity of doubling (e.g., slaflaf, or generally, XX; where X stands for a phonological constituent). Across languages, doubling is known to elicit conflicting preferences at different levels of linguistic analysis (phonology vs. morphology). Here, we show that these preferences are active in the brains of individual speakers, and they are demonstrably distinct from sensorimotor pressures. We first demonstrate that doubling in novel English words elicits divergent percepts: Viewed as meaningless (phonological) forms, doubling is disliked (e.g., slaflaf < slafmak), but once doubling in form is systematically linked to meaning (e.g., slaf = ball, slaflaf = balls), the doubling aversion shifts into a reliable (morphological) preference. We next show that sign-naive speakers spontaneously project these principles to novel signs in American Sign Language, and their capacity to do so depends on the structure of their spoken language (English vs. Hebrew). These results demonstrate that linguistic preferences doubly dissociate from sensorimotor demands: A single stimulus can elicit diverse percepts, yet these percepts are invariant across stimulus modality--for speech and signs. These conclusions are in line with the possibility that some linguistic principles are abstract, and they apply broadly across language modality.

  8. Magneto-conductive mechanisms in the La-site doped double-layered La1.4Ca1.6Mn2O7 manganites

    NASA Astrophysics Data System (ADS)

    Mahamdioua, N.; Amira, A.; Boudjadja, Y.; Saoudel, A.; Altintas, S. P.; Varilci, A.; Terzioglu, C.

    2016-11-01

    Magneto-conductive mechanisms and properties of La1.2Re0.2Ca1.6Mn2O7 (Re=La, Pr, Y, Gd and Eu) have been investigated. In the low temperature range, combining residual resistivity, weak localization effect, electron-electron and electron-phonon interactions in a model, fit well the resistivity curves of undoped, Pr-doped and Y-doped samples. The Gd-doped and Eu-doped ones require the introduction of the small polaron metallic conduction. In the high temperature range, 3D-Mott's variable range hopping (3D-VRH) is the best model to fit resistivity of the undoped, Pr-doped and Y-doped samples, while Effros-Shklovskii model (ES-VRH) is the best one for Gd-doped and Eu-doped samples. In the entire temperature range, the percolation model fit well the resistivity. Using 3D-VRH model, the density of state (DOS) decreases with doping by Gd and Eu, whereas mean hopping distance Rh(T) and mean hopping energy Eh(T) increase. This may explain the resistivity increase and the crossover to the ES-VRH model. Values of Rh(T) vary between 1.811 and 1.030 nm, which allow us to suggest 3D-VRH as the best model fitting current results. Eh(T) values range from 0.1157 to 0.2635 eV. The DOS increases as increasing magnetic field while Rh(T) and Eh(T) decrease, which is in agreement with the observed decrease of resistivity.

  9. The Potential Impact of an Auction Based Retention Bonus and Other Factors on Continuation Rates of General Dentists Completing Their Initial Obligation

    DTIC Science & Technology

    2007-03-01

    Agreement ($$) Oral Maxillofacial Surgeons 25,000 38,000 50,000 Comprehensive/Operative Dentistry 20,000 30,000 40,000 Endodontics 20,000 30,000 40,000... Endodontics (Advanced Clinical Practice) 13,000 19,000 25,000 General Dentistry [Comprehensive Dentistry] (Advanced Clinical Practice) 13,000 19,000...84 R. Preston McAfee and John McMillan, “Auctions and Bidding,” Journal of Economic Literature XXV

  10. 47 CFR 90.903 - Competitive bidding mechanisms.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Bureau will establish and may vary the sequence in which 800 MHz SMR licenses for Spectrum Blocks A through V will be auctioned. (b) Grouping. (1) All EA licenses for Spectrum Blocks A through V will be... the auction, an alternative method of grouping these licenses for auction. (2) Spectrum blocks...

  11. 47 CFR 90.903 - Competitive bidding mechanisms.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Bureau will establish and may vary the sequence in which 800 MHz SMR licenses for Spectrum Blocks A through V will be auctioned. (b) Grouping. (1) All EA licenses for Spectrum Blocks A through V will be... the auction, an alternative method of grouping these licenses for auction. (2) Spectrum blocks...

  12. Electric fields and double layers in plasmas

    NASA Technical Reports Server (NTRS)

    Singh, Nagendra; Thiemann, H.; Schunk, R. W.

    1987-01-01

    Various mechanisms for driving double layers in plasmas are briefly described, including applied potential drops, currents, contact potentials, and plasma expansions. Some dynamical features of the double layers are discussed. These features, as seen in simulations, laboratory experiments, and theory, indicate that double layers and the currents through them undergo slow oscillations which are determined by the ion transit time across an effective length of the system in which double layers form. It is shown that a localized potential dip forms at the low potential end of a double layer, which interrupts the electron current through it according to the Langmuir criterion, whenever the ion flux into the double is disrupted. The generation of electric fields perpendicular to the ambient magnetic field by contact potentials is also discussed. Two different situations were considered; in one, a low-density hot plasma is sandwiched between high-density cold plasmas, while in the other a high-density current sheet permeates a low-density background plasma. Perpendicular electric fields develop near the contact surfaces. In the case of the current sheet, the creation of parallel electric fields and the formation of double layers are also discussed when the current sheet thickness is varied. Finally, the generation of electric fields and double layers in an expanding plasma is discussed.

  13. Electric fields and double layers in plasmas

    NASA Astrophysics Data System (ADS)

    Singh, Nagendra; Thiemann, H.; Schunk, R. W.

    1987-05-01

    Various mechanisms for driving double layers in plasmas are briefly described, including applied potential drops, currents, contact potentials, and plasma expansions. Some dynamical features of the double layers are discussed. These features, as seen in simulations, laboratory experiments, and theory, indicate that double layers and the currents through them undergo slow oscillations which are determined by the ion transit time across an effective length of the system in which double layers form. It is shown that a localized potential dip forms at the low potential end of a double layer, which interrupts the electron current through it according to the Langmuir criterion, whenever the ion flux into the double is disrupted. The generation of electric fields perpendicular to the ambient magnetic field by contact potentials is also discussed. Two different situations were considered; in one, a low-density hot plasma is sandwiched between high-density cold plasmas, while in the other a high-density current sheet permeates a low-density background plasma. Perpendicular electric fields develop near the contact surfaces. In the case of the current sheet, the creation of parallel electric fields and the formation of double layers are also discussed when the current sheet thickness is varied. Finally, the generation of electric fields and double layers in an expanding plasma is discussed.

  14. Explanation by the double-metal-ion mechanism of catalysis for the differential metal ion effects on the cleavage rates of 5′-oxy and 5′-thio substrates by a hammerhead ribozyme

    PubMed Central

    Zhou, De-Min; Zhang, Li-He; Taira, Kazunari

    1997-01-01

    In a previous examination using natural all-RNA substrates that contained either a 5′-oxy or 5′-thio leaving group at the cleavage site, we demonstrated that (i) the attack by the 2′-oxygen at C17 on the phosphorus atom is the rate-limiting step only for the substrate that contains a 5′-thio group (R11S) and (ii) the departure of the 5′ leaving group is the rate-limiting step for the natural all-RNA substrate (R11O) in both nonenzymatic and hammerhead ribozyme-catalyzed reactions; the energy diagrams for these reactions were provided in our previous publication. In this report we found that the rate of cleavage of R11O by a hammerhead ribozyme was enhanced 14-fold when Mg2+ ions were replaced by Mn2+ ions, whereas the rate of cleavage of R11S was enhanced only 2.2-fold when Mg2+ ions were replaced by Mn2+ ions. This result appears to be exactly the opposite of that predicted from the direct coordination of the metal ion with the leaving 5′-oxygen, because a switch in metal ion specificity was not observed with the 5′-thio substrate. However, our quantitative analyses based on the previously provided energy diagram indicate that this result is in accord with the double-metal-ion mechanism of catalysis. PMID:9405614

  15. Cardiovascular risk and mortality in end-stage renal disease patients undergoing dialysis: sleep study, pulmonary function, respiratory mechanics, upper airway collapsibility, autonomic nervous activity, depression, anxiety, stress and quality of life: a prospective, double blind, randomized controlled clinical trial

    PubMed Central

    2013-01-01

    Background Chronic kidney disease (CKD) is one of the most serious public health problems. The increasing prevalence of CKD in developed and developing countries has led to a global epidemic. The hypothesis proposed is that patients undergoing dialysis would experience a marked negative influence on physiological variables of sleep and autonomic nervous system activity, compromising quality of life. Methods/Design A prospective, consecutive, double blind, randomized controlled clinical trial is proposed to address the effect of dialysis on sleep, pulmonary function, respiratory mechanics, upper airway collapsibility, autonomic nervous activity, depression, anxiety, stress and quality of life in patients with CKD. The measurement protocol will include body weight (kg); height (cm); body mass index calculated as weight/height2; circumferences (cm) of the neck, waist, and hip; heart and respiratory rates; blood pressures; Mallampati index; tonsil index; heart rate variability; maximum ventilatory pressures; negative expiratory pressure test, and polysomnography (sleep study), as well as the administration of specific questionnaires addressing sleep apnea, excessive daytime sleepiness, depression, anxiety, stress, and quality of life. Discussion CKD is a major public health problem worldwide, and its incidence has increased in part by the increased life expectancy and increasing number of cases of diabetes mellitus and hypertension. Sleep disorders are common in patients with renal insufficiency. Our hypothesis is that the weather weight gain due to volume overload observed during interdialytic period will influence the degree of collapsibility of the upper airway due to narrowing and predispose to upper airway occlusion during sleep, and to investigate the negative influences of haemodialysis in the physiological variables of sleep, and autonomic nervous system, and respiratory mechanics and thereby compromise the quality of life of patients. Trial registration The

  16. Observing Double Stars

    NASA Astrophysics Data System (ADS)

    Genet, Russell M.; Fulton, B. J.; Bianco, Federica B.; Martinez, John; Baxter, John; Brewer, Mark; Carro, Joseph; Collins, Sarah; Estrada, Chris; Johnson, Jolyon; Salam, Akash; Wallen, Vera; Warren, Naomi; Smith, Thomas C.; Armstrong, James D.; McGaughey, Steve; Pye, John; Mohanan, Kakkala; Church, Rebecca

    2012-05-01

    Double stars have been systematically observed since William Herschel initiated his program in 1779. In 1803 he reported that, to his surprise, many of the systems he had been observing for a quarter century were gravitationally bound binary stars. In 1830 the first binary orbital solution was obtained, leading eventually to the determination of stellar masses. Double star observations have been a prolific field, with observations and discoveries - often made by students and amateurs - routinely published in a number of specialized journals such as the Journal of Double Star Observations. All published double star observations from Herschel's to the present have been incorporated in the Washington Double Star Catalog. In addition to reviewing the history of visual double stars, we discuss four observational technologies and illustrate these with our own observational results from both California and Hawaii on telescopes ranging from small SCTs to the 2-meter Faulkes Telescope North on Haleakala. Two of these technologies are visual observations aimed primarily at published "hands-on" student science education, and CCD observations of both bright and very faint doubles. The other two are recent technologies that have launched a double star renaissance. These are lucky imaging and speckle interferometry, both of which can use electron-multiplying CCD cameras to allow short (30 ms or less) exposures that are read out at high speed with very low noise. Analysis of thousands of high speed exposures allows normal seeing limitations to be overcome so very close doubles can be accurately measured.

  17. Cast Double Base Propellants: Process Mechanics

    DTIC Science & Technology

    1953-02-01

    thc rate of dilatation, of the casting powder and its .’ate of penetration by casting liquid, 2. 2. To measure the rate of dilatation of the...powders a)d fini.shed charges, 2.4. To dctcrminc the r,ate of solution of the casti)g owdcr in thc castino llquid, 2.5. To measturc the chrngo iu...O aad humidity cabiact ( sect a t 20OC. , 5 5 --c lat:v* hCum-’IitY) fo t ea,t 24 hours befo-re coiiencin-g the test. The gralcz L-u-o thc ):) mo,,sur

  18. Multidimensional period doubling structures.

    PubMed

    Lee, Jeong Yup; Flom, Dvir; Ben-Abraham, Shelomo I

    2016-05-01

    This paper develops the formalism necessary to generalize the period doubling sequence to arbitrary dimension by straightforward extension of the substitution and recursion rules. It is shown that the period doubling structures of arbitrary dimension are pure point diffractive. The symmetries of the structures are pointed out.

  19. Unzipping mechanism of the double-stranded DNA unwinding by a hexameric helicase: the effect of the 3' arm and the stability of the dsDNA on the unwinding activity of the Escherichia coli DnaB helicase.

    PubMed

    Galletto, Roberto; Jezewska, Maria J; Bujalowski, Wlodzimierz

    2004-10-08

    The effect of two structural elements of a replication DNA fork substrate, the length of the 3' arm of the fork and the stability of the double-stranded DNA (dsDNA) part, on the kinetics of the dsDNA unwinding by the Escherichia coli hexameric helicase DnaB protein has been examined under single turnover conditions using the rapid quench-flow technique. The length of the 3' arm of the replication fork, i.e. the number of nucleotides in the arm, is a major structural factor that controls the unwinding rate and processivity of the helicase. The data show the existence of an optimal length of the 3' arm where there is the highest unwinding rate and processivity, indicating that during the unwinding process, the helicase transiently interacts with the 3' arm at a specific distance on the arm with respect to the duplex part of the DNA. Moreover, the area on the enzyme that engages in interactions has also a discrete size. For DNA substrates with the 3' arm containing 14, or less, nucleotide residues, the DnaB helicase becomes a completely distributive enzyme. However, the 3' arm is not a "specific activating cofactor" in the unwinding reaction. Rather, the 3' arm plays a role as a mechanical fulcrum for the enzyme, necessary to provide support for the advancing large helicase molecule on the opposite strand of the DNA. Binding of ATP is necessary to engage the 3' arm with the DnaB helicase, but it does not change the initial distribution of complexes of the enzyme with the DNA fork substrate. Stability of the dsDNA has a significant effect on the unwinding rate and processivity. The unwinding rate constant is a decreasing linear function of the fractional content of GC base-pairs in the dsDNA, indicating that the activation of the unwinding step is proportional to the stability of the nucleic acid.

  20. On fair, effective and efficient REDD mechanism design.

    PubMed

    Obersteiner, Michael; Huettner, Michael; Kraxner, Florian; McCallum, Ian; Aoki, Kentaro; Böttcher, Hannes; Fritz, Steffen; Gusti, Mykola; Havlik, Petr; Kindermann, Georg; Rametsteiner, Ewald; Reyers, Belinda

    2009-11-27

    The issues surrounding 'Reduced Emissions from Deforestation and Forest Degradation' (REDD) have become a major component of continuing negotiations under the United Nations Framework Convention on Climate Change (UNFCCC). This paper aims to address two key requirements of any potential REDD mechanism: first, the generation of measurable, reportable and verifiable (MRV) REDD credits; and secondly, the sustainable and efficient provision of emission reductions under a robust financing regime.To ensure the supply of MRV credits, we advocate the establishment of an 'International Emission Reference Scenario Coordination Centre' (IERSCC). The IERSCC would act as a global clearing house for harmonized data to be used in implementing reference level methodologies. It would be tasked with the collection, reporting and subsequent processing of earth observation, deforestation- and degradation driver information in a globally consistent manner. The IERSCC would also assist, coordinate and supervise the computation of national reference scenarios according to rules negotiated under the UNFCCC. To overcome the threats of "market flooding" on the one hand and insufficient economic incentives for REDD on the other hand, we suggest an 'International Investment Reserve' (IIR) as REDD financing framework. In order to distribute the resources of the IIR we propose adopting an auctioning mechanism. Auctioning not only reveals the true emission reduction costs, but might also allow for incentivizing the protection of biodiversity and socio-economic values. The introduced concepts will be vital to ensure robustness, environmental integrity and economic efficiency of the future REDD mechanism.

  1. Double Degenerate Binary Systems

    SciTech Connect

    Yakut, K.

    2011-09-21

    In this study, angular momentum loss via gravitational radiation in double degenerate binary (DDB)systems (NS + NS, NS + WD, WD + WD, and AM CVn) is studied. Energy loss by gravitational waves has been estimated for each type of systems.

  2. New insight on double-double radio galaxies

    NASA Astrophysics Data System (ADS)

    Nandi, Sumana

    2016-07-01

    Striking examples of episodic jet activity in active galactic nuclei (AGN) are the double-double radio galaxies (DDRGs) with two pairs of lobes emerging from the same central engine. The number of DDRGs reported so far is very limited, and it is important to identify more of these to provide a significant statistical overview of the conditions to trigger the jets and the role of jets in terms of feedback mechanisms that affect the host galaxies. Although most DDRGs were believed initially to be giant radio sources with sizes more than a Mpc, a significant number of smaller sized candidate DDRGs have also been identified in our recent study. We started GMRT observation of this sample to confirm that the sources are related to distinct epochs of nuclear activity. In addition to this radio observation we have also investigated the properties of the host galaxies and their environments to understand the triggering mechanisms for recurrent jet emission. Here, I will highlight the main results from these observations and discuss on the possible scenarios responsible for the episodic activity in different types of DDRGs .

  3. Comparing the 2000 and 2005 factors affecting the selling price of feeder cattle sold at Arkansas livestock auctions.

    PubMed

    Troxel, T R; Barham, B L

    2007-12-01

    The objectives of the study were to determine how factors affecting the selling price of feeder calves changed from 2000 to 2005 and to examine the perception that discounts narrow or even disappear as calf supplies decrease and selling prices increase. Data from weekly Arkansas livestock auctions were collected from January 1 to December 31 in 2000 and 2005. Data included calf sex, breed type, color, muscle score, horn status, frame score, fill, condition, health, and BW. Mean selling prices for 2000 and 2005 were $92.91 +/- 15.05 and $118.32 +/- 15.13 (mean +/- SD; $/45.45 kg), respectively. Individual price observations were subtracted from the respective annual means and became the dependent variable. The selling prices for feeder calves sold in groups of 2 to 5 calves and in groups of >/= 6 calves were greater in 2005 than 2000 (P < 0.001). Steers received a greater premium ($6.48 +/- 0.09 vs. $6.02 +/- 0.08; mean +/- SE) and bull calves received greater discounts ($0.30 +/- 0.14 vs. $1.68 +/- 0.09) in 2005 than in 2000. Breeds types that increased in value from 2000 to 2005 were Angus x Hereford, Angus, Angus x Charolais, and Brahman (P < 0.001). Breed types that received a reduced selling price in 2005 compared with 2000 (P < 0.001) were one-fourth Brahman Cross, Charolais, Charolais x Limousin, Hereford x Limousin, Limousin, Limousin x one-fourth Brahman, Longhorn, Saler and Simmental. Yellow-white face, black-white face, black, and gray feeder calves received an increase in selling price from 2000 to 2005 (P < 0.001). Although fewer horned feeder calves were sold in 2005 (P < 0.01), they received greater discounts in 2005 than 2000 (-$2.86 +/- 0.16 and -$0.51 +/- 0.09; P < 0.001). In 2005, large-framed feeder calves did not receive the premium detected in 2000, but medium-framed feeder calves in 2005 received a greater selling price compared with 2000. Feeder calves with a muscle score of 1 received a greater premium in 2005 compared with 2000 ($2.58 +/- 0

  4. "Objective" Science at Auction.

    ERIC Educational Resources Information Center

    Mokhiber, Russell

    1998-01-01

    Discusses a report published by the Center for Public Integrity (CPI) entitled Toxic Deception: How the Chemical Industry Manipulates Science, Bends the Law, and Endangers Your Health. Voices concerns that the federal regulatory system receives favors from the chemical industry that create bias. (PVD)

  5. Comment on 'Biphoton double-slit experiment'

    SciTech Connect

    Oriols, X.

    2005-01-01

    In a recent paper [Phys. Rev. A 68, 033803 (2003)] experimental results on a double-slit configuration with two entangled bosons are presented. The authors argue that their data contradicts the de Broglie-Bohm interpretation of quantum mechanics. In this Comment we show that this conclusion is incorrect.

  6. Fluid dynamics of double diffusive systems

    SciTech Connect

    Koseff, J.R.

    1989-04-07

    A study of mixing processes in doubly diffusive systems is being conducted. Continuous gradients of two diffusing components (heat and salinity in our case) are being used as initial conditions, and forcing is introduced by lateral heating and surface shear. The goals of the proposed work include: (1) quantification of the effects of finite amplitude disturbances on stable, double diffusive systems, particularly with respect to lateral heating, (2) development of an improved understanding of the physical phenomena present in wind-driven shear flows in double diffusive stratified environments, (3) increasing our knowledge-base on turbulent flow in stratified environments and how to represent it, and (4) formulation of a numerical code for such flows. The work is being carried out in an experimental facility which is located in the Stanford Environmental Fluid Mechanics Laboratory, and on laboratory minicomputers and CRAY computers. In particular we are focusing on the following key issues: (1) the formation and propagation of double diffusive intrusions away from a heated wall and the effects of lateral heating on the double diffusive system; (2) the interaction between the double diffusively influenced fluxes and the turbulence induced fluxes; (3) the measurement of heat and mass fluxes; and (4) the influence of double diffusive gradients on mixed layer deepening. 1 fig.

  7. Bond-rearrangement and ionization mechanisms in the photo-double-ionization of simple hydrocarbons (C2H4, C2H3F, and 1,1-C2H2F2) near and above threshold

    DOE PAGES

    Gaire, B.; Gatton, A. S.; Wiegandt, F.; ...

    2016-09-14

    We have investigated bond-rearrangement driven by photo-double-ionization (PDI) near and above the double ionization threshold in a sequence of carbon-carbon double bonded hydrocarbon molecules: ethylene, fluoroethylene, and 1,1-difluoroethylene. We employ the kinematically complete cold target recoil ion momentum spectroscopy (COLTRIMS) method to resolve all photo-double-ionization events leading to two-ionic fragments. We observe changes in the branching ratios of different dissociative ionization channels depending on the presence of none, one, or two fluorine atoms. The role of the fluorine atom in the bond-rearrangement channels is intriguing as evident by the re-ordering of the threshold energies of the PDI in the fluorinatedmore » molecules. These effects offer a compelling argument that the electronegativity of the fluorine (or the polarity of the molecule) strongly influences the potential energy surfaces of the molcules and drives bond-rearrangement during the dissociation process. The energy sharing and the relative angle between the 3D-momentum vectors of the two electrons provide clear evidence of direct and indirect PDI processes.« less

  8. Bond-rearrangement and ionization mechanisms in the photo-double-ionization of simple hydrocarbons (C2H4, C2H3F, and 1,1-C2H2F2) near and above threshold

    SciTech Connect

    Gaire, B.; Gatton, A. S.; Wiegandt, F.; Neff, J.; Janke, C.; Zeller, S.; Reedy, D.; Rajput, J.; Ben-Itzahk, I.; Landers, A. L.; Belkacem, A.; Weber, Th.

    2016-09-14

    We have investigated bond-rearrangement driven by photo-double-ionization (PDI) near and above the double ionization threshold in a sequence of carbon-carbon double bonded hydrocarbon molecules: ethylene, fluoroethylene, and 1,1-difluoroethylene. We employ the kinematically complete cold target recoil ion momentum spectroscopy (COLTRIMS) method to resolve all photo-double-ionization events leading to two-ionic fragments. We observe changes in the branching ratios of different dissociative ionization channels depending on the presence of none, one, or two fluorine atoms. The role of the fluorine atom in the bond-rearrangement channels is intriguing as evident by the re-ordering of the threshold energies of the PDI in the fluorinated molecules. These effects offer a compelling argument that the electronegativity of the fluorine (or the polarity of the molecule) strongly influences the potential energy surfaces of the molcules and drives bond-rearrangement during the dissociation process. The energy sharing and the relative angle between the 3D-momentum vectors of the two electrons provide clear evidence of direct and indirect PDI processes.

  9. Double checking: a second look

    PubMed Central

    Chreim, Samia; Forster, Alan

    2015-01-01

    Abstract Rationale, aims and objectives Double checking is a standard practice in many areas of health care, notwithstanding the lack of evidence supporting its efficacy. We ask in this study: ‘How do front line practitioners conceptualize double checking? What are the weaknesses of double checking? What alternate views of double checking could render it a more robust process?’ Method This is part of a larger qualitative study based on 85 semi‐structured interviews of health care practitioners in general internal medicine and obstetrics and neonatology; thematic analysis of the transcribed interviews was undertaken. Inductive and deductive themes are reported. Results Weaknesses in the double checking process include inconsistent conceptualization of double checking, double (or more) checking as a costly and time‐consuming procedure, double checking trusted as an accepted and stand‐alone process, and double checking as preventing reporting of near misses. Alternate views of double checking that would render it a more robust process include recognizing that double checking requires training and a dedicated environment, Introducing automated double checking, and expanding double checking beyond error detection. These results are linked with the concepts of collective efficiency thoroughness trade off (ETTO), an in‐family approach, and resilience. Conclusion(s) Double checking deserves more questioning, as there are limitations to the process. Practitioners could view double checking through alternate lenses, and thus help strengthen this ubiquitous practice that is rarely challenged. PMID:26568537

  10. Double-helix stellarator

    SciTech Connect

    Moroz, P.E.

    1997-09-01

    A new stellarator configuration, the Double-Helix Stellarator (DHS), is introduced. This novel configuration features a double-helix center post as the only helical element of the stellarator coil system. The DHS configuration has many unique characteristics. One of them is the extreme low plasma aspect ratio, A {approx} 1--1.2. Other advantages include a high enclosed volume, appreciable rotational transform, and a possibility of extreme-high-{beta} MHD equilibria. Moreover, the DHS features improved transport characteristics caused by the absence of the magnetic field ripple on the outboard of the torus. Compactness, simplicity and modularity of the coil system add to the DHS advantages for fusion applications.

  11. Double arch mirror study

    NASA Technical Reports Server (NTRS)

    Vukobratovich, D.; Hillman, D.

    1983-01-01

    The development of a method of mounting light weight glass mirrors for astronomical telescopes compatible with the goals of the Shuttle Infrared Telescope Facility (SIRTF) was investigated. A 20 in. diameter double arch lightweight mirror previously fabricated was modified to use a new mount configuration. This mount concept was developed and fabricated. The mounting concept of the double mounting mirror is outlined. The modifications made to the mirror, fabrication of the mirror mount, and room temperature testing of the mirror and mount and the extension of the mirror and mount concept to a full size (40 in. diameter) primary mirror for SIRTF are discussed.

  12. Double Photoionization Near Threshold

    NASA Technical Reports Server (NTRS)

    Wehlitz, Ralf

    2007-01-01

    The threshold region of the double-photoionization cross section is of particular interest because both ejected electrons move slowly in the Coulomb field of the residual ion. Near threshold both electrons have time to interact with each other and with the residual ion. Also, different theoretical models compete to describe the double-photoionization cross section in the threshold region. We have investigated that cross section for lithium and beryllium and have analyzed our data with respect to the latest results in the Coulomb-dipole theory. We find that our data support the idea of a Coulomb-dipole interaction.

  13. Double photoionization of hydrocarbons and aromatic molecules

    NASA Astrophysics Data System (ADS)

    Wehlitz, R.

    2016-11-01

    This article reviews the recent progress in the field of double photoionization of hydrocarbons and aromatic molecules using synchrotron radiation. First I will describe the importance of carbon-based molecules, which are all around us and are literally part of our life. They exhibit intriguing properties some of which can be probed via double photoionization, i.e., the simultaneous emission of two electrons. Furthermore, I will discuss the different mechanisms that can lead to a doubly charged organic molecule and will highlight those findings by comparing them with the results for atoms and other (simple) molecules. Finally, I will give an outlook on future directions on this subject.

  14. Global prevalence of double Benioff zones.

    PubMed

    Brudzinski, Michael R; Thurber, Clifford H; Hacker, Bradley R; Engdahl, E Robert

    2007-06-08

    Double Benioff zones provide opportunities for insight into seismogenesis because the underlying mechanism must explain two layers of deep earthquakes and the separation between them. We characterize layer separation inside subducting plates with a coordinate rotation to calculate the slab-normal distribution of earthquakes. Benchmark tests on well-established examples confirm that layer separation is accurately quantified with global seismicity catalogs alone. Global analysis reveals double Benioff zones in 30 segments, including all 16 subduction zones investigated, with varying subducting plate ages and stress orientations, which implies that they are inherent in subducting plates. Layer separation increases with age and is more consistent with dehydration of antigorite than chlorite.

  15. Weathering the Double Whammy.

    ERIC Educational Resources Information Center

    Wellman, Jane V.

    2002-01-01

    Discusses how governing boards can help their institutions weather the "double-whammy" of doing more with less: identify the institution's short-term and long-term challenges; refocus the institution's mission, planning, and programming; assess and integrate the institution's tuition, aid, and outreach strategies; redouble the…

  16. Sun Packs Double Punch

    NASA Video Gallery

    On August 3, the sun packed a double punch, emitting a M6.0-class flare at 9:43 am EDT. This video is of the second, slightly stronger M9.3-class flare at 11:41 pm EDT. Both flares had significant ...

  17. Rosette (Double Blossom)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rosette, or double blossom, is a serious disease of erect blackberries that is limited to the genus Rubus. Rosette may occur on trailing blackberries and dewberries, but rarely on red and black raspberries. In the United States, rosette occurs from New Jersey to Illinois and southwest to Texas and i...

  18. Double resonator cantilever accelerometer

    DOEpatents

    Koehler, D.R.

    1982-09-23

    A digital quartz accelerometer includes a pair of spaced double-ended tuning forks fastened at one end to a base and at the other end through a spacer mass. Transverse movement of the resonator members stresses one and compresses the other, providing a differential frequency output which is indicative of acceleration.

  19. Double resonator cantilever accelerometer

    DOEpatents

    Koehler, Dale R.

    1984-01-01

    A digital quartz accelerometer includes a pair of spaced double-ended tuning forks fastened at one end to a base and at the other end through a spacer mass. Transverse movement of the resonator members stresses one and compresses the other, providing a differential frequency output which is indicative of acceleration.

  20. Teaching the Double Layer.

    ERIC Educational Resources Information Center

    Bockris, J. O'M.

    1983-01-01

    Suggests various methods for teaching the double layer in electrochemistry courses. Topics addressed include measuring change in absolute potential difference (PD) at interphase, conventional electrode potential scale, analyzing absolute PD, metal-metal and overlap electron PDs, accumulation of material at interphase, thermodynamics of electrified…