Investment Strategies Used as Spectroscopy of Financial Markets Reveal New Stylized Facts

PubMed Central

Zhou, Wei-Xing; Mu, Guo-Hua; Chen, Wei; Sornette, Didier

2011-01-01

We propose a new set of stylized facts quantifying the structure of financial markets. The key idea is to study the combined structure of both investment strategies and prices in order to open a qualitatively new level of understanding of financial and economic markets. We study the detailed order flow on the Shenzhen Stock Exchange of China for the whole year of 2003. This enormous dataset allows us to compare (i) a closed national market (A-shares) with an international market (B-shares), (ii) individuals and institutions, and (iii) real traders to random strategies with respect to timing that share otherwise all other characteristics. We find in general that more trading results in smaller net return due to trading frictions, with the exception that the net return is independent of the trading frequency for A-share individual traders. We unveiled quantitative power laws with non-trivial exponents, that quantify the deterioration of performance with frequency and with holding period of the strategies used by traders. Random strategies are found to perform much better than real ones, both for winners and losers. Surprising large arbitrage opportunities exist, especially when using zero-intelligence strategies. This is a diagnostic of possible inefficiencies of these financial markets. PMID:21935403

Optimal Dynamic Strategies for Index Tracking and Algorithmic Trading

NASA Astrophysics Data System (ADS)

Ward, Brian

In this thesis we study dynamic strategies for index tracking and algorithmic trading. Tracking problems have become ever more important in Financial Engineering as investors seek to precisely control their portfolio risks and exposures over different time horizons. This thesis analyzes various tracking problems and elucidates the tracking errors and strategies one can employ to minimize those errors and maximize profit. In Chapters 2 and 3, we study the empirical tracking properties of exchange traded funds (ETFs), leveraged ETFs (LETFs), and futures products related to spot gold and the Chicago Board Option Exchange (CBOE) Volatility Index (VIX), respectively. These two markets provide interesting and differing examples for understanding index tracking. We find that static strategies work well in the nonleveraged case for gold, but fail to track well in the corresponding leveraged case. For VIX, tracking via neither ETFs, nor futures\\ portfolios succeeds, even in the nonleveraged case. This motivates the need for dynamic strategies, some of which we construct in these two chapters and further expand on in Chapter 4. There, we analyze a framework for index tracking and risk exposure control through financial derivatives. We derive a tracking condition that restricts our exposure choices and also define a slippage process that characterizes the deviations from the index over longer horizons. The framework is applied to a number of models, for example, Black Scholes model and Heston model for equity index tracking, as well as the Square Root (SQR) model and the Concatenated Square Root (CSQR) model for VIX tracking. By specifying how each of these models fall into our framework, we are able to understand the tracking errors in each of these models. Finally, Chapter 5 analyzes a tracking problem of a different kind that arises in algorithmic trading: schedule following for optimal execution. We formulate and solve a stochastic control problem to obtain the optimal trading rates using both market and limit orders. There is a quadratic terminal penalty to ensure complete liquidation as well as a trade speed limiter and trader director to provide better control on the trading rates. The latter two penalties allow the trader to tailor the magnitude and sign (respectively) of the optimal trading rates. We demonstrate the applicability of the model to following a benchmark schedule. In addition, we identify conditions on the model parameters to ensure optimality of the controls and finiteness of the associated value functions. Throughout the chapter, numerical simulations are provided to demonstrate the properties of the optimal trading rates.

Boldness predicts an individual's position along an exploration-exploitation foraging trade-off.

PubMed

Patrick, Samantha C; Pinaud, David; Weimerskirch, Henri

2017-09-01

Individuals do not have complete information about the environment and therefore they face a trade-off between gathering information (exploration) and gathering resources (exploitation). Studies have shown individual differences in components of this trade-off but how stable these strategies are in a population and the intrinsic drivers of these differences is not well understood. Top marine predators are expected to experience a particularly strong trade-off as many species have large foraging ranges and their prey often have a patchy distribution. This environment leads these species to exhibit pronounced exploration and exploitation phases but differences between individuals are poorly resolved. Personality differences are known to be important in foraging behaviour but also in the trade-off between exploration and exploitation. Here we test whether personality predicts an individual exploration-exploitation strategy using wide ranging wandering albatrosses (Diomedea exulans) as a model system. Using GPS tracking data from 276 wandering albatrosses, we extract foraging parameters indicative of exploration (searching) and exploitation (foraging) and show that foraging effort, time in patch and size of patch are strongly correlated, demonstrating these are indicative of an exploration-exploitation (EE) strategy. Furthermore, we show these are consistent within individuals and appear stable in the population, with no reproductive advantage. The searching and foraging behaviour of bolder birds placed them towards the exploration end of the trade-off, whereas shy birds showed greater exploitation. This result provides a mechanism through which individual foraging strategies may emerge. Age and sex affected components of the trade-off, but not the trade-off itself, suggesting these factors may drive behavioural compensation to maintain resource acquisition and this was supported by the evidence that there were no fitness consequence of any EE trait nor the trade-off itself. These results demonstrate a clear trade-off between information gathering and exploitation of prey patches, and reveals for the first time that boldness may drive these differences. This provides a mechanism through which widely reported links between personality and foraging may emerge. © 2017 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

A Sequence Mining Method to Predict the Bidding Strategy of Trading Agents

NASA Astrophysics Data System (ADS)

Nikolaidou, Vivia; Mitkas, Pericles A.

In this work, we describe the process used in order to predict the bidding strategy of trading agents. This was done in the context of the Reverse TAC, or CAT, game of the Trading Agent Competition. In this game, a set of trading agents, buyers or sellers, are provided by the server and they trade their goods in one of the markets operated by the competing agents. Better knowledge of the strategy of the trading agents will allow a market maker to adapt its incentives and attract more agents to its own market. Our prediction was based on the time series of the traders’ past bids, taking into account the variation of each bid compared to its history. The results proved to be of satisfactory accuracy, both in the game’s context and when compared to other existing approaches.

Fitness trade-offs in pest management and intercropping with colour: an evolutionary framework and potential application

PubMed Central

Farkas, Timothy E

2015-01-01

An important modern goal of plant science research is to develop tools for agriculturalists effective at curbing yield losses to insect herbivores, but resistance evolution continuously threatens the efficacy of pest management strategies. The high-dose/refuge strategy has been employed with some success to curb pest adaptation, and has been shown to be most effective when fitness costs (fitness trade-offs) of resistance are high. Here, I use eco-evolutionary reasoning to demonstrate the general importance of fitness trade-offs for pest control, showing that strong fitness trade-offs mitigate the threat of pest adaptation, even if adaptation were to occur. I argue that novel pest management strategies evoking strong fitness trade-offs are the most likely to persist in the face of unbridled pest adaptation, and offer the manipulation of crop colours as a worked example of one potentially effective strategy against insect herbivores. PMID:26495038

Fitness trade-offs in pest management and intercropping with colour: an evolutionary framework and potential application.

PubMed

Farkas, Timothy E

2015-10-01

An important modern goal of plant science research is to develop tools for agriculturalists effective at curbing yield losses to insect herbivores, but resistance evolution continuously threatens the efficacy of pest management strategies. The high-dose/refuge strategy has been employed with some success to curb pest adaptation, and has been shown to be most effective when fitness costs (fitness trade-offs) of resistance are high. Here, I use eco-evolutionary reasoning to demonstrate the general importance of fitness trade-offs for pest control, showing that strong fitness trade-offs mitigate the threat of pest adaptation, even if adaptation were to occur. I argue that novel pest management strategies evoking strong fitness trade-offs are the most likely to persist in the face of unbridled pest adaptation, and offer the manipulation of crop colours as a worked example of one potentially effective strategy against insect herbivores.

78 FR 54502 - Self-Regulatory Organizations; Financial Industry Regulatory Authority, Inc.; Notice of Filing of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-04

... transactions. Transactions that originate from unrelated algorithms or separate and distinct trading strategies... transactions were undertaken for manipulative or other fraudulent purposes. Algorithms or trading strategies... activity and the use of algorithms by firms to make trading decisions, FINRA has observed an increase in...

To 'enable our legal product to compete effectively with the transit market': British American Tobacco's strategies in Thailand following the 1990 GATT dispute.

PubMed

MacKenzie, Ross; Lee, Kelley; LeGresley, Eric

2015-08-21

The opening of the Thai tobacco market, following action brought by the US Trade Representative under the General Agreement on Tariffs and Trade, is seen as a key case study of the tensions between trade and health policy. Interpretations of the dispute cast it, either as an example of how trade agreements undermine national policy-making, or how governments can adopt effective public health protections compliant with international trade rules. As a UK-based company, British American Tobacco has been regarded as peripheral to this dispute. This paper argues that its close monitoring of the illegal trade during this period, the role of smuggling in the company's global business strategy, and its management of the relative supply and pricing of legal and illegal products after market opening provide a fuller understanding of the interests and roles of transnational tobacco companies and the government in this dispute. The findings have important policy implications, notably the role of effective governance in countries facing pressure to open their tobacco sectors, need to better understand corporate-level activities within an increasingly globalised tobacco industry, and need to address the intertwined legal and illegal trade in implementing the WHO Framework Convention on Tobacco Control Protocol to Eliminate Illicit Trade in Tobacco Products.

The influence of gender and age on choice of flood adaptation strategies: A case study of Zambia and Namibia..

NASA Astrophysics Data System (ADS)

Mabuku, Monde

2017-04-01

It is reported that flood events will increase due to variability and change in climate, thus increasing the number of people exposed to flooding disasters. This exposure negatively impacts rural households' livelihoods. Women, men, young, old has distinctive vulnerability and this shapes the choice of flood adaptation strategies. This calls for a need to adopt group specific interventions to strengthen local adaptive capacity to flooding for the affected population. The purpose of this case study was to determine the adaptation strategies to floods adopted by rural households in the Zambezi region of Namibia and Mwandi district of Zambia. The study further examined how gender and age influenced the choice of different adaptation strategies. Six focus group meetings and a questionnaire survey of 207 randomly sampled households were conducted in the flood prone areas of the study. Descriptive statistics results on the adaptation strategies indicated that a majority of the households in Namibia learnt to live with floods (86%),practiced mafisa cattle trade (86%), flood water harvesting (68%), practiced early and late planting (63%), prayed (55%), practiced conservation agriculture (54%) and fish farming (53%). In Zambia the adaptation strategies were; conservation agriculture (91%), acquiring better skills on preparedness (66%), flood water harvesting (63%), praying (60%), and flood proofing (52%). Logistic regression analysis showed that age positively and significantly influenced the likelihood of taking up adaptation strategies such as tree planting, relocation to higher ground, flood water harvesting, early and late planting. The older the respondents the more likely they were to adopt the strategies mentioned. More young ones were more likely to adopt acquiring better skills on flood preparedness and mafisa cattle trading than the old ones. Gender positively and significantly influenced mafisa cattle trade (p<0.01), male headed households were more likely to adopt mafisa cattle trading than the females. The study concludes that factors such as age and gender influences the choice of any adaptation strategy. For policy purposes, this suggests that relevant stakeholders' interventions should consider gender and age in order to enhance the adaptive capacity of rural households to flooding. This study will inform decision makers and practitioners to consider women and men, young and old in designing programs and projects aimed at strengthening disaster risk reduction and management in the two countries and under similar environments.

The Impact of Designed Democratic Pedagogy on Trade and Industrial Students' Work Values and Attitudes.

ERIC Educational Resources Information Center

Gregson, James A.; Trawinski, Sheila C.

A study was conducted to provide further evidence that democratic teaching strategies were more effective than indoctrinational strategies to teach work values and attitudes. A literature review provided overwhelming evidence that democratic strategies were much more effective than indoctrinational strategies. However, vocational education…

Functional Trait Strategies of Trees in Dry and Wet Tropical Forests Are Similar but Differ in Their Consequences for Succession

PubMed Central

Lohbeck, Madelon; Lebrija-Trejos, Edwin; Martínez-Ramos, Miguel; Meave, Jorge A.; Poorter, Lourens; Bongers, Frans

2015-01-01

Global plant trait studies have revealed fundamental trade-offs in plant resource economics. We evaluated such trait trade-offs during secondary succession in two species-rich tropical ecosystems that contrast in precipitation: dry deciduous and wet evergreen forests of Mexico. Species turnover with succession in dry forest largely relates to increasing water availability and in wet forest to decreasing light availability. We hypothesized that while functional trait trade-offs are similar in the two forest systems, the successful plant strategies in these communities will be different, as contrasting filters affect species turnover. Research was carried out in 15 dry secondary forest sites (5-63 years after abandonment) and in 17 wet secondary forest sites (<1-25 years after abandonment). We used 11 functional traits measured on 132 species to make species-trait PCA biplots for dry and wet forest and compare trait trade-offs. We evaluated whether multivariate plant strategies changed during succession, by calculating a ‘Community-Weighted Mean’ plant strategy, based on species scores on the first two PCA-axes. Trait spectra reflected two main trade-off axes that were similar for dry and wet forest species: acquisitive versus conservative species, and drought avoiding species versus evergreen species with large animal-dispersed seeds. These trait associations were consistent when accounting for evolutionary history. Successional changes in the most successful plant strategies reflected different functional trait spectra depending on the forest type. In dry forest the community changed from having drought avoiding strategies early in succession to increased abundance of evergreen strategies with larger seeds late in succession. In wet forest the community changed from species having mainly acquisitive strategies to those with more conservative strategies during succession. These strategy changes were explained by increasing water availability during dry forest succession and increasing light scarcity during wet forest succession. Although similar trait spectra were observed among dry and wet secondary forest species, the consequences for succession were different resulting from contrasting environmental filters. PMID:25919023

Participatory action research methodology in disaster research: results from the World Trade Center evacuation study.

PubMed

Gershon, Robyn R M; Rubin, Marcie S; Qureshi, Kristine A; Canton, Allison N; Matzner, Frederick J

2008-10-01

Participatory action research (PAR) methodology is an effective tool in identifying and implementing risk-reduction interventions. It has been used extensively in occupational health research, but not, to our knowledge, in disaster research. A PAR framework was incorporated into the World Trade Center evacuation study, which was designed to identify the individual, organizational, and structural (environmental) factors that affected evacuation from the World Trade Center Towers 1 and 2 on September 11, 2001. PAR teams-comprising World Trade Center evacuees, study investigators, and expert consultants-worked collaboratively to develop a set of recommendations designed to facilitate evacuation from high-rise office buildings and reduce risk of injury among evacuees. Two PAR teams worked first separately and then collectively to identify data-driven strategies for improvement of high-rise building evacuation. The teams identified interventions targeting individual, organizational, and structural (environmental) barriers to safe and rapid evacuation. PAR teams were effective in identifying numerous feasible and cost-effective strategies for improvement of high-rise emergency preparedness and evacuation. This approach may have utility in other workplace disaster prevention planning and response programs.

A Novel Quantitative Approach to Women’s Reproductive Strategies

PubMed Central

Milne, Fritha H.; Judge, Debra S.

2012-01-01

The patterned way in which individuals allocate finite resources to various components of reproduction (e.g. mating effort, reproductive timing and parental investment) is described as a reproductive strategy. As energy is limited, trade-offs between and within aspects of reproductive strategies are expected. The first aim of this study was to derive aspects of reproductive strategies using complete reproductive histories from 718 parous Western Australian women. Factor analysis using a subset of these participants resulted in six factors that represented ‘short-term mating strategy’, ‘early onset of sexual activity’, ‘reproductive output’, ‘timing of childbearing’, ‘breastfeeding’, and ‘child spacing’. This factor structure was internally validated by replication using a second independent subset of the data. The second aim of this study examined trade-offs between aspects of reproductive strategies derived from aim one. Factor scores calculated for each woman were incorporated in generalised linear models and interaction terms were employed to examine the effect of mating behaviour on the relationships between reproductive timing, parental investment and overall reproductive success. Early sexual activity correlates with early reproductive onset for women displaying more long-term mating strategies. Women with more short-term mating strategies exhibit a trade-off between child quantity and child quality not observed in women with a long-term mating strategy. However, women with a short-term mating strategy who delay reproductive timing exhibit levels of parental investment (measured as breastfeeding duration per child) similar to that of women with long-term mating strategies. Reproductive delay has fitness costs (fewer births) for women displaying more short-term mating strategies. We provide empirical evidence that reproductive histories of contemporary women reflect aspects of reproductive strategies, and associations between these strategic elements, as predicted from life history theory. PMID:23056440

Roadmap for the protection of disaster research participants: findings from the World Trade Center Evacuation Study.

PubMed

Qureshi, Kristine A; Gershon, Robyn R M; Smailes, Elizabeth; Raveis, Victoria H; Murphy, Bridgette; Matzner, Frederick; Fleischman, Alan R

2007-01-01

This report addresses the development, implementation, and evaluation of a protocol designed to protect participants from inadvertent emotional harm or further emotional trauma due to their participation in the World Trade Center Evacuation (WTCE) Study research project. This project was designed to identify the individual, organizational, and structural (environmental) factors associated with evacuation from the World Trade Center Towers 1 and 2 on 11 September 2001. Following published recommended practices for protecting potentially vulnerable disaster research participants, protective strategies and quality assurance processes were implemented and evaluated, including an assessment of the impact of participation on study subjects enrolled in the qualitative phase of the WTCE Study. The implementation of a protocol designed to protect disaster study participants from further emotional trauma was feasible and effective in minimizing risk and monitoring for psychological injury associated with study participation. Details about this successful strategy provide a roadmap that can be applied in other post-disaster research investigations.

Results of the Particulate Contamination Control Trade Study for Space Suit Life Support Development

NASA Technical Reports Server (NTRS)

Cognata, Thomas J.; Conger, Bruce; Paul, Heather L.

2009-01-01

As the United States plans to return astronauts to the moon and eventually to Mars, designing the most effective, efficient, and robust space suit life support system that will operate successfully in these dusty environments is vital. There is some knowledge of the contaminants and level of infiltration expected from the Lunar and Mars dust, however risk mitigation strategies and filtration designs to prevent contamination within the space suit life support system are still undefined. A trade study was initiated to identify and address these concerns, and to develop new requirements for the Constellation Space Suit Element (CSSE) Portable Life Support System (PLSS). This trade study investigates historical methods of particulate contamination control in space suits and vehicles, and evaluated the possibility of using commercial technologies for this application. In addition, the trade study examined potential filtration designs. This paper summarizes the results of this trade study.

Exploring pig trade patterns to inform the design of risk-based disease surveillance and control strategies

PubMed Central

Guinat, C.; Relun, A.; Wall, B.; Morris, A.; Dixon, L.; Pfeiffer, D. U.

2016-01-01

An understanding of the patterns of animal contact networks provides essential information for the design of risk-based animal disease surveillance and control strategies. This study characterises pig movements throughout England and Wales between 2009 and 2013 with a view to characterising spatial and temporal patterns, network topology and trade communities. Data were extracted from the Animal and Plant Health Agency (APHA)’s RADAR (Rapid Analysis and Detection of Animal-related Risks) database, and analysed using descriptive and network approaches. A total of 61,937,855 pigs were moved through 872,493 movements of batches in England and Wales during the 5-year study period. Results show that the network exhibited scale-free and small-world topologies, indicating the potential for diseases to quickly spread within the pig industry. The findings also provide suggestions for how risk-based surveillance strategies could be optimised in the country by taking account of highly connected holdings, geographical regions and time periods with the greatest number of movements and pigs moved, as these are likely to be at higher risk for disease introduction. This study is also the first attempt to identify trade communities in the country, information which could be used to facilitate the pig trade and maintain disease-free status across the country in the event of an outbreak. PMID:27357836

Molecular and Neuroendocrine Approaches to Understanding Trade-offs: Food, Sex, Aggression, Stress, and Longevity-An Introduction to the Symposium.

PubMed

Schneider, Jill E; Deviche, Pierre

2017-12-01

Life history strategies are composed of multiple fitness components, each of which incurs costs and benefits. Consequently, organisms cannot maximize all fitness components simultaneously. This situation results in a dynamic array of trade-offs in which some fitness traits prevail at the expense of others, often depending on context. The identification of specific constraints and trade-offs has helped elucidate physiological mechanisms that underlie variation in behavioral and physiological life history strategies. There is general recognition that trade-offs are made at the individual and population level, but much remains to be learned concerning the molecular neuroendocrine mechanisms that underlie trade-offs. For example, we still do not know whether the mechanisms that underlie trade-offs at the individual level relate to trade-offs at the population level. To advance our understanding of trade-offs, we organized a group of speakers who study neuroendocrine mechanisms at the interface of traits that are not maximized simultaneously. Speakers were invited to represent research from a wide range of taxa including invertebrates (e.g., worms and insects), fish, nonavian reptiles, birds, and mammals. Three general themes emerged. First, the study of trade-offs requires that we investigate traditional endocrine mechanisms that include hormones, neuropeptides, and their receptors, and in addition, other chemical messengers not traditionally included in endocrinology. The latter group includes growth factors, metabolic intermediates, and molecules of the immune system. Second, the nomenclature and theory of neuroscience that has dominated the study of behavior is being re-evaluated in the face of evidence for the peripheral actions of so-called neuropeptides and neurotransmitters and the behavioral repercussions of these actions. Finally, environmental and ecological contexts continue to be critical in unmasking molecular mechanisms that are hidden when study animals are housed in enclosed spaces, with unlimited food, without competitors or conspecifics, and in constant ambient conditions. © The Author 2017. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology.

75 FR 29993 - Department of Commerce: Trade Promotion Coordinating Committee Renewable Energy and Energy...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-28

... Coordinating Committee Renewable Energy and Energy Efficiency Export Strategy To Support the National Export... Trade Promotion Coordinating Committee's (TPCC) Renewable Energy and Energy Efficiency Working Group is developing a U.S. Renewable Energy and Energy Efficiency Export Strategy (the Strategy) to guide U.S...

To ‘enable our legal product to compete effectively with the transit market’: British American Tobacco’s strategies in Thailand following the 1990 GATT dispute

PubMed Central

MacKenzie, Ross; Lee, Kelley; LeGresley, Eric

2016-01-01

The opening of the Thai tobacco market, following action brought by the US Trade Representative under the GATT, is seen as a key case study of the tensions between trade and health policy. Interpretations of the dispute cast it, either as an example of how trade agreements undermine national policy making, or how governments can adopt effective public health protections compliant with international trade rules. As a UK-based company, British American Tobacco has been regarded as peripheral to this dispute. This paper argues that its close monitoring of the illegal trade during this period, the role of smuggling in the company’s global business strategy, and its management of the relative supply and pricing of legal and illegal products after market opening provide a fuller understanding of the interests and roles of transnational tobacco companies and the government in this dispute. The findings have important policy implications, notably the role of effective governance in countries facing pressure to open their tobacco sectors, need to better understand corporate-level activities within an increasingly globalized tobacco industry, and need to address the intertwined legal and illegal trade in implementing the WHO Framework Convention on Tobacco Control Protocol to Eliminate Illicit Trade in Tobacco Products. PMID:26295971

Quantified moving average strategy of crude oil futures market based on fuzzy logic rules and genetic algorithms

NASA Astrophysics Data System (ADS)

Liu, Xiaojia; An, Haizhong; Wang, Lijun; Guan, Qing

2017-09-01

The moving average strategy is a technical indicator that can generate trading signals to assist investment. While the trading signals tell the traders timing to buy or sell, the moving average cannot tell the trading volume, which is a crucial factor for investment. This paper proposes a fuzzy moving average strategy, in which the fuzzy logic rule is used to determine the strength of trading signals, i.e., the trading volume. To compose one fuzzy logic rule, we use four types of moving averages, the length of the moving average period, the fuzzy extent, and the recommend value. Ten fuzzy logic rules form a fuzzy set, which generates a rating level that decides the trading volume. In this process, we apply genetic algorithms to identify an optimal fuzzy logic rule set and utilize crude oil futures prices from the New York Mercantile Exchange (NYMEX) as the experiment data. Each experiment is repeated for 20 times. The results show that firstly the fuzzy moving average strategy can obtain a more stable rate of return than the moving average strategies. Secondly, holding amounts series is highly sensitive to price series. Thirdly, simple moving average methods are more efficient. Lastly, the fuzzy extents of extremely low, high, and very high are more popular. These results are helpful in investment decisions.

An improved moving average technical trading rule

NASA Astrophysics Data System (ADS)

Papailias, Fotis; Thomakos, Dimitrios D.

2015-06-01

This paper proposes a modified version of the widely used price and moving average cross-over trading strategies. The suggested approach (presented in its 'long only' version) is a combination of cross-over 'buy' signals and a dynamic threshold value which acts as a dynamic trailing stop. The trading behaviour and performance from this modified strategy are different from the standard approach with results showing that, on average, the proposed modification increases the cumulative return and the Sharpe ratio of the investor while exhibiting smaller maximum drawdown and smaller drawdown duration than the standard strategy.

77 FR 55251 - Self-Regulatory Organizations; EDGX Exchange, Inc.; Notice of Filing and Immediate Effectiveness...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-07

... nature of any liquidity the originating routing strategy seeks. Purchasers of Edge Routed Liquidity... market participants to improve their trading and order routing strategies by being able to discern missed... market research and analysis as well as back-testing of new trading strategies to gauge effectiveness...

Breeds of risk-adjusted fundamentalist strategies in an order-driven market

NASA Astrophysics Data System (ADS)

LiCalzi, Marco; Pellizzari, Paolo

2006-01-01

This paper studies an order-driven stock market where agents have heterogeneous estimates of the fundamental value of the risky asset. The agents are budget-constrained and follow a value-based trading strategy which buys or sells depending on whether the price of the asset is below or above its risk-adjusted fundamental value. This environment generates returns that are remarkably leptokurtic and fat-tailed. By extending the study over a grid of different parameters for the fundamentalist trading strategy, we exhibit the existence of monotone relationships between the bid-ask spread demanded by the agents and several statistics of the returns. We conjecture that this effect, coupled with positive dependence of the risk premium on the volatility, generates positive feedbacks that might explain volatility bursts.

Derivative Trade Optimizing Model Utilizing GP Based on Behavioral Finance Theory

NASA Astrophysics Data System (ADS)

Matsumura, Koki; Kawamoto, Masaru

This paper proposed a new technique which makes the strategy trees for the derivative (option) trading investment decision based on the behavioral finance theory and optimizes it using evolutionary computation, in order to achieve high profitability. The strategy tree uses a technical analysis based on a statistical, experienced technique for the investment decision. The trading model is represented by various technical indexes, and the strategy tree is optimized by the genetic programming(GP) which is one of the evolutionary computations. Moreover, this paper proposed a method using the prospect theory based on the behavioral finance theory to set psychological bias for profit and deficit and attempted to select the appropriate strike price of option for the higher investment efficiency. As a result, this technique produced a good result and found the effectiveness of this trading model by the optimized dealings strategy.

Energy futures: Trading opportunities for the 1980's

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

Treat, J.E.; Cowie, S.; Davidson, F.E.

1984-01-01

This text gives a broad background in both theory and practice of energy futures trading. It details successful contract requirements. It analyzes fundamental and technical pricing and using both to manage risk and achieve trading objectives. Hedging strategy, financial aspects of trading, accounting procedures, internal control systems and tax implications are all expertly covered. The book concludes with the potential impact of futures trading on the structure of world markets. Contents: Energy futures: an overview; Exchanges and their contracts; Fundamental analysis and the theory of hedging; The principles of technical analysis; Putting it all together; Integrated trading strategies; Energy futures;more » Financing and exposure management in the oil industry; Accounting principles, taxation, and internal control; The potential impacts of trading in oil futures on the world oil market; Appendix; Glossary; Index.« less

The plant perceptron connects environment to development.

PubMed

Scheres, Ben; van der Putten, Wim H

2017-03-15

Plants cope with the environment in a variety of ways, and ecological analyses attempt to capture this through life-history strategies or trait-based categorization. These approaches are limited because they treat the trade-off mechanisms that underlie plant responses as a black box. Approaches that involve the molecular or physiological analysis of plant responses to the environment have elucidated intricate connections between developmental and environmental signals, but in only a few well-studied model species. By considering diversity in the plant response to the environment as the adaptation of an information-processing network, new directions can be found for the study of life-history strategies, trade-offs and evolution in plants.

Are Random Trading Strategies More Successful than Technical Ones?

PubMed Central

Biondo, Alessio Emanuele; Pluchino, Alessandro; Rapisarda, Andrea; Helbing, Dirk

2013-01-01

In this paper we explore the specific role of randomness in financial markets, inspired by the beneficial role of noise in many physical systems and in previous applications to complex socio-economic systems. After a short introduction, we study the performance of some of the most used trading strategies in predicting the dynamics of financial markets for different international stock exchange indexes, with the goal of comparing them to the performance of a completely random strategy. In this respect, historical data for FTSE-UK, FTSE-MIB, DAX, and S & P500 indexes are taken into account for a period of about 15–20 years (since their creation until today). PMID:23874594

Discrete homotopy analysis for optimal trading execution with nonlinear transient market impact

NASA Astrophysics Data System (ADS)

Curato, Gianbiagio; Gatheral, Jim; Lillo, Fabrizio

2016-10-01

Optimal execution in financial markets is the problem of how to trade a large quantity of shares incrementally in time in order to minimize the expected cost. In this paper, we study the problem of the optimal execution in the presence of nonlinear transient market impact. Mathematically such problem is equivalent to solve a strongly nonlinear integral equation, which in our model is a weakly singular Urysohn equation of the first kind. We propose an approach based on Homotopy Analysis Method (HAM), whereby a well behaved initial trading strategy is continuously deformed to lower the expected execution cost. Specifically, we propose a discrete version of the HAM, i.e. the DHAM approach, in order to use the method when the integrals to compute have no closed form solution. We find that the optimal solution is front loaded for concave instantaneous impact even when the investor is risk neutral. More important we find that the expected cost of the DHAM strategy is significantly smaller than the cost of conventional strategies.

77 FR 42780 - Self-Regulatory Organizations; NASDAQ OMX PHLX LLC; Notice of Filing of Proposed Rule Change...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-20

... strategies effectively via STOs,\\8\\ particularly in the current fast and volatile multi-faceted trading and... proposal, to allow execution of more effective trading and hedging strategies on the Exchange. See... strategies on the Exchange. The Exchange believes that this precision is increasingly necessary, and in fact...

Modeling the trade-off between diet costs and methane emissions: A goal programming approach.

PubMed

Moraes, L E; Fadel, J G; Castillo, A R; Casper, D P; Tricarico, J M; Kebreab, E

2015-08-01

Enteric methane emission is a major greenhouse gas from livestock production systems worldwide. Dietary manipulation may be an effective emission-reduction tool; however, the associated costs may preclude its use as a mitigation strategy. Several studies have identified dietary manipulation strategies for the mitigation of emissions, but studies examining the costs of reducing methane by manipulating diets are scarce. Furthermore, the trade-off between increase in dietary costs and reduction in methane emissions has only been determined for a limited number of production scenarios. The objective of this study was to develop an optimization framework for the joint minimization of dietary costs and methane emissions based on the identification of a set of feasible solutions for various levels of trade-off between emissions and costs. Such a set of solutions was created by the specification of a systematic grid of goal programming weights, enabling the decision maker to choose the solution that achieves the desired trade-off level. Moreover, the model enables the calculation of emission-mitigation costs imputing a trading value for methane emissions. Emission imputed costs can be used in emission-unit trading schemes, such as cap-and-trade policy designs. An application of the model using data from lactating cows from dairies in the California Central Valley is presented to illustrate the use of model-generated results in the identification of optimal diets when reducing emissions. The optimization framework is flexible and can be adapted to jointly minimize diet costs and other potential environmental impacts (e.g., nitrogen excretion). It is also flexible so that dietary costs, feed nutrient composition, and animal nutrient requirements can be altered to accommodate various production systems. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Regulating Interest when Learning Online: Potential Motivation and Performance Trade-Offs

ERIC Educational Resources Information Center

Sansone, Carol; Smith, Jessi L.; Thoman, Dustin B.; MacNamara, Atara

2012-01-01

Online learning may be particularly sensitive to self-regulatory trade-offs between maintaining interest and performance. Undergraduates in online or on-campus sections of the same course rated strategies used to motivate studying for the first exam, and interest after the first exam and at semester's end. First exam and final class grades were…

Adaptive evolution of defense ability leads to diversification of prey species.

PubMed

Zu, Jian; Wang, Jinliang; Du, Jianqiang

2014-06-01

In this paper, by using the adaptive dynamics approach, we investigate how the adaptive evolution of defense ability promotes the diversity of prey species in an initial one-prey-two-predator community. We assume that the prey species can evolve to a safer strategy such that it can reduce the predation risk, but a prey with a high defense ability for one predator may have a low defense ability for the other and vice versa. First, by using the method of critical function analysis, we find that if the trade-off is convex in the vicinity of the evolutionarily singular strategy, then this singular strategy is a continuously stable strategy. However, if the trade-off is weakly concave near the singular strategy and the competition between the two predators is relatively weak, then the singular strategy may be an evolutionary branching point. Second, we find that after the branching has occurred in the prey strategy, if the trade-off curve is globally concave, then the prey species might eventually evolve into two specialists, each caught by only one predator species. However, if the trade-off curve is convex-concave-convex, the prey species might eventually branch into two partial specialists, each being caught by both of the two predators and they can stably coexist on the much longer evolutionary timescale.

78 FR 16875 - Request of the U.S. Intellectual Property Enforcement Coordinator for Public Comments...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-19

..._strategy_on_mitigating_the_theft_of_u.s._trade_secrets.pdf http:/www.whitehouse.gov/sites/default/files/omb/ IPEC/admin_strategy_on_mitigating_the_theft_of_u.s._trade_ secrets.pdf. A related OMB blog post is...

Literature-Based Teaching in the Content Areas: 40 Strategies for K-8 Classrooms

ERIC Educational Resources Information Center

Cox, Carole

2011-01-01

Grounded in theory and best-practices research, this practical text provides teachers with 40 strategies for using fiction and non-fiction trade books to teach in five key content areas: language arts and reading, social studies, mathematics, science, and the arts. Each strategy provides everything a teacher needs to get started: a classroom…

Threat Assessment and Remediation Analysis (TARA)

DTIC Science & Technology

2014-10-01

of countermeasure selection strategies that prescribe the application of countermeasures based on level of risk tolerance. This paper outlines the...catalog data, which are discussed later in this paper . The methodology can be described as conjoined trade studies, where the first trade identifies and...ranks vulnerabilities based on assessed risk, and the second identifies and selects countermeasures based on assessed utility and cost. This paper

78 FR 28654 - Self-Regulatory Organizations; NASDAQ OMX PHLX LLC; Notice of Filing of Proposed Rule Change, as...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-15

... response is received to sell the strategy at $0.55. If the market for option A becomes $1.05 bid, offered... of $0.60. The residual 24 strategy contracts will trade against the two market maker responses in a... trade against the two market maker responses with MM1 executing 10 strategy contracts and MM2 executing...

Unveiling correlations between financial variables and topological metrics of trading networks: Evidence from a stock and its warrant

NASA Astrophysics Data System (ADS)

Li, Ming-Xia; Jiang, Zhi-Qiang; Xie, Wen-Jie; Xiong, Xiong; Zhang, Wei; Zhou, Wei-Xing

2015-02-01

Traders develop and adopt different trading strategies attempting to maximize their profits in financial markets. These trading strategies not only result in specific topological structures in trading networks, which connect the traders with the pairwise buy-sell relationships, but also have potential impacts on market dynamics. Here, we present a detailed analysis on how the market behaviors are correlated with the structures of traders in trading networks based on audit trail data for the Baosteel stock and its warrant at the transaction level from 22 August 2005 to 23 August 2006. In our investigation, we divide each trade day into 48 rolling time windows with a length of 5 min, construct a trading network within each window, and obtain a time series of over 11,600 trading networks. We find that there are strongly simultaneous correlations between the topological metrics (including network centralization, assortative index, and average path length) of trading networks that characterize the patterns of order execution and the financial variables (including return, volatility, intertrade duration, and trading volume) for the stock and its warrant. Our analysis may shed new lights on how the microscopic interactions between elements within complex system affect the system's performance.

Modeling Sexual Selection in Túngara Frog and Rationality of Mate Choice.

PubMed

Vargas Bernal, Esteban; Sanabria Malagon, Camilo

2017-12-01

The males of the species of frogs Engystomops pustulosus produce simple and complex calls to lure females, as a way of intersexual selection. Complex calls lead males to a greater reproductive success than what simple calls do. However, the complex calls are also more attractive to their main predator, the bat Trachops cirrhosus. Therefore, as M. Ryan suggests in (The túngara frog: a study in sexual selection and communication. University of Chicago Press, Chicago, 1985), the complexity of the calls lets the frogs keep a trade-off between reproductive success and predation. In this paper, we verify this trade-off from the perspective of game theory. We first model the proportion of simple calls as a symmetric game of two strategies. We also model the effect of adding a third strategy, males that keep quiet and intercept females, which would play a role of intrasexual selection. Under the assumption that the decision of the males takes into account this trade-off between reproductive success and predation, our model reproduces the observed behavior reported in the literature with minimal assumption on the parameters. From the model with three strategies, we verify that the quiet strategy could only coexists with the simple and complex strategies if the rate at which quiet males intercept females is high, which explains the rarity of the quiet strategy. We conclude that the reproductive strategy of the male frog E. pustulosus is rational.

Considerations for Architecture Level Trade Studies for Environmental Sensors

NASA Technical Reports Server (NTRS)

Peterson, Craig

2010-01-01

Comparisons of key characteristics of environmental sensors such as technology readiness levels, mass, power, volume, and detection capabilities are essential for initial trade studies to determine likely candidates for further development and evaluation. However, these trade studies only provide part of the information necessary to make selection decisions. Ultimately, the sensors must be judged based on the overall system architectures and operational scenarios for which they are intended. This means that additional characteristics, such as architectural needs for redundancy, operational lifetime, ability to maintain calibration, and repair and replacement strategies, among others, must also be considered. Given that these characteristics can be extremely time-consuming and costly to obtain, careful planning is essential to minimize the effort involved. In this paper, an approach is explored for determining an effective yet comprehensive set of architecture level trades which is minimally impacted by the inevitable changes in operational (mission) scenarios. The approach will also identify and integrate the various facilities and opportunities required to obtain the desired architecture level trade information.

Application of the Cluster Expansion to a Mathematical Model of the Long Memory Phenomenon in a Financial Market

NASA Astrophysics Data System (ADS)

Kuroda, Koji; Maskawa, Jun-ichi; Murai, Joshin

2013-08-01

Empirical studies of the high frequency data in stock markets show that the time series of trade signs or signed volumes has a long memory property. In this paper, we present a discrete time stochastic process for polymer model which describes trader's trading strategy, and show that a scale limit of the process converges to superposition of fractional Brownian motions with Hurst exponents and Brownian motion, provided that the index γ of the time scale about the trader's investment strategy coincides with the index δ of the interaction range in the discrete time process. The main tool for the investigation is the method of cluster expansion developed in the mathematical study of statistical mechanics.

Emerging diseases and implications for global trade.

PubMed

Thiermann, A

2004-08-01

Emerging diseases could have a devastating impact on international trade unless there is a change in the traditional approach to disease control and new holistic prevention and control strategies are adopted. The impact that emerging diseases will have on international trade will depend on several factors, such as the nature of the pathogen, the degree of co-ordination and integration between Veterinary Services and Public Health authorities, the ability to rapidly detect and respond to a disease appearance, and the existing trade relationship between countries. Strategies to control emerging diseases will be more effective if competent authorities and veterinary infrastructures in particular, integrate their public and animal health objectives into a single strategy. The co-ordinating role of international standard setting organisations such as the World Organisation for Animal Health (OIE) will be crucial. This paper discusses the events contributing to the appearance and spread of new emerging diseases and examines the changing roles of Veterinary Services and international organisations. Reference is also made to measures that can be taken towards minimising potential trade disruptions caused by the appearance of an emerging disease.

76 FR 64144 - Self-Regulatory Organizations; NASDAQ OMX PHLX LLC; Notice of Filing of Proposed Rule Change To...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-17

... closely tailor their investment and risk management strategies and decisions. Furthermore, the Exchange... investment, trading, and risk management purposes. 2. Statutory Basis The Exchange believes that its proposal... having the ability to execute hedging and trading strategies via STOs,\\8\\ particularly in the current...

The New York Trade Publishers and CD-ROM: Where Are They Heading?

ERIC Educational Resources Information Center

Newmark, Eileen

1994-01-01

Discusses the strategies top trade publishers, including Putnam New Media, Paramount Communications, Random House, Penguin USA, and Reader's Digest, are taking toward CD-ROM publishing. Strategies include purchasing electronic media companies; setting up an independent business; and building a new media business by integrating new efforts into the…

Optimization of European call options considering physical delivery network and reservoir operation rules

NASA Astrophysics Data System (ADS)

Cheng, Wei-Chen; Hsu, Nien-Sheng; Cheng, Wen-Ming; Yeh, William W.-G.

2011-10-01

This paper develops alternative strategies for European call options for water purchase under hydrological uncertainties that can be used by water resources managers for decision making. Each alternative strategy maximizes its own objective over a selected sequence of future hydrology that is characterized by exceedance probability. Water trade provides flexibility and enhances water distribution system reliability. However, water trade between two parties in a regional water distribution system involves many issues, such as delivery network, reservoir operation rules, storage space, demand, water availability, uncertainty, and any existing contracts. An option is a security giving the right to buy or sell an asset; in our case, the asset is water. We extend a flow path-based water distribution model to include reservoir operation rules. The model simultaneously considers both the physical distribution network as well as the relationships between water sellers and buyers. We first test the model extension. Then we apply the proposed optimization model for European call options to the Tainan water distribution system in southern Taiwan. The formulation lends itself to a mixed integer linear programming model. We use the weighing method to formulate a composite function for a multiobjective problem. The proposed methodology provides water resources managers with an overall picture of water trade strategies and the consequence of each strategy. The results from the case study indicate that the strategy associated with a streamflow exceedence probability of 50% or smaller should be adopted as the reference strategy for the Tainan water distribution system.

Glossary on the World Trade Organisation and public health: part 2.

PubMed

Labonte, Ronald; Sanger, Matthew

2006-09-01

Part 1 of this glossary introduced different health and trade arguments, overviewed the history of the World Trade Organisation (WTO), defined key "trade talk" terms, and reviewed three WTO treaties concerned with trade in goods (GATT 1994, the Agreement on Agriculture, and the Agreement on Sanitary and Phytosanitary Measures). Part 2 reviews five more agreements and the growing number of bilateral and regional trade agreements, and concludes with a commentary on different strategies proposed to ensure that health is not compromised by trade liberalization treaties.

Glossary on the World Trade Organisation and public health: part 2

PubMed Central

Labonte, Ronald; Sanger, Matthew

2006-01-01

Part 1 of this glossary introduced different health and trade arguments, overviewed the history of the World Trade Organisation (WTO), defined key “trade talk” terms, and reviewed three WTO treaties concerned with trade in goods (GATT 1994, the Agreement on Agriculture, and the Agreement on Sanitary and Phytosanitary Measures). Part 2 reviews five more agreements and the growing number of bilateral and regional trade agreements, and concludes with a commentary on different strategies proposed to ensure that health is not compromised by trade liberalisation treaties. PMID:16905715

Training for Trade: A Partnership Strategy.

ERIC Educational Resources Information Center

Wismer, Jack N.

1994-01-01

Discusses the role of community colleges in providing international trade education and training, highlighting the importance of building partnerships. Describes methods for building partnerships, eight current community college training-for-trade (TFT) programs, and training services and resources. Suggests that TFT programs must become a…

Introducing Hurst exponent in pair trading

NASA Astrophysics Data System (ADS)

Ramos-Requena, J. P.; Trinidad-Segovia, J. E.; Sánchez-Granero, M. A.

2017-12-01

In this paper we introduce a new methodology for pair trading. This new method is based on the calculation of the Hurst exponent of a pair. Our approach is inspired by the classical concepts of co-integration and mean reversion but joined under a unique strategy. We will show how Hurst approach presents better results than classical Distance Method and Correlation strategies in different scenarios. Results obtained prove that this new methodology is consistent and suitable by reducing the drawdown of trading over the classical ones getting as a result a better performance.

Market analyses of livestock trade networks to inform the prevention of joint economic and epidemiological risks.

PubMed

Moslonka-Lefebvre, Mathieu; Gilligan, Christopher A; Monod, Hervé; Belloc, Catherine; Ezanno, Pauline; Filipe, João A N; Vergu, Elisabeta

2016-03-01

Conventional epidemiological studies of infections spreading through trade networks, e.g., via livestock movements, generally show that central large-size holdings (hubs) should be preferentially surveyed and controlled in order to reduce epidemic spread. However, epidemiological strategies alone may not be economically optimal when costs of control are factored in together with risks of market disruption from targeting core holdings in a supply chain. Using extensive data on animal movements in supply chains for cattle and swine in France, we introduce a method to identify effective strategies for preventing outbreaks with limited budgets while minimizing the risk of market disruptions. Our method involves the categorization of holdings based on position along the supply chain and degree of market share. Our analyses suggest that trade has a higher risk of propagating epidemics through cattle networks, which are dominated by exchanges involving wholesalers, than for swine. We assess the effectiveness of contrasting interventions from the perspectives of regulators and the market, using percolation analysis. We show that preferentially targeting minor, non-central agents can outperform targeting of hubs when the costs to stakeholders and the risks of market disturbance are considered. Our study highlights the importance of assessing joint economic-epidemiological risks in networks underlying pathogen propagation and trade. © 2016 The Authors.

Market analyses of livestock trade networks to inform the prevention of joint economic and epidemiological risks

PubMed Central

Gilligan, Christopher A.; Belloc, Catherine; Filipe, João A. N.; Vergu, Elisabeta

2016-01-01

Conventional epidemiological studies of infections spreading through trade networks, e.g. via livestock movements, generally show that central large-size holdings (hubs) should be preferentially surveyed and controlled in order to reduce epidemic spread. However, epidemiological strategies alone may not be economically optimal when costs of control are factored in together with risks of market disruption from targeting core holdings in a supply chain. Using extensive data on animal movements in supply chains for cattle and swine in France, we introduce a method to identify effective strategies for preventing outbreaks with limited budgets while minimizing the risk of market disruptions. Our method involves the categorization of holdings based on position along the supply chain and degree of market share. Our analyses suggest that trade has a higher risk of propagating epidemics through cattle networks, which are dominated by exchanges involving wholesalers, than for swine. We assess the effectiveness of contrasting interventions from the perspectives of regulators and the market, using percolation analysis. We show that preferentially targeting minor, non-central agents can outperform targeting of hubs when the costs to stakeholders and the risks of market disturbance are considered. Our study highlights the importance of assessing joint economic–epidemiological risks in networks underlying pathogen propagation and trade. PMID:26984191

Underprepared Learners Practice Brief. Acceleration Strategies Series. TAACCCT Equipping Community Colleges for Success

ERIC Educational Resources Information Center

Jobs For the Future, 2016

2016-01-01

This is the second brief in a series on strategies for Trade Adjustment Assistance Community College Career Training (TAACCCT) grantees and other educators. The Department of Labor's Trade Adjustment Assistance Community College Career Training (TAACCCT) program is providing nearly $2 billion in funds to build the capacity of the nation's…

Prior Learning Assessment Practice Brief. Acceleration Strategies Series. TAACCCT Equipping Community Colleges for Success

ERIC Educational Resources Information Center

Jobs For the Future, 2016

2016-01-01

This is the first brief in a series on strategies for Trade Adjustment Assistance Community College Career Training (TAACCCT) grantees and other educators. The Department of Labor's Trade Adjustment Assistance Community College Career Training (TAACCCT) program is providing nearly $2 billion in funds to build the capacity of the nation's community…

Interactions between behavioral and life-history trade-offs in the evolution of integrated predator-defense plasticity.

PubMed

Cressler, Clayton E; King, Aaron A; Werner, Earl E

2010-09-01

Inducible defense, which is phenotypic plasticity in traits that affect predation risk, is taxonomically widespread and has been shown to have important ecological consequences. However, it remains unclear what factors promote the evolution of qualitatively different defense strategies and when evolution should favor strategies that involve modification of multiple traits. Previous theory suggests that individual-level trade-offs play a key role in defense evolution, but most of this work has assumed that trade-offs are independent. Here we show that the shape of the behavioral trade-off between foraging gain and predation risk determines the interaction between this trade-off and the life-history trade-off between growth and reproduction. The interaction between these fundamental trade-offs determines the optimal investment into behavioral and life-history defenses. Highly nonlinear foraging-predation risk trade-offs favor the evolution of behavioral defenses, while linear trade-offs favor life-history defenses. Between these extremes, integrated defense responses are optimal, with defense expression strongly depending on ontogeny. We suggest that these predictions may be general across qualitatively different defenses. Our results have important implications for theory on the ecological effects of inducible defense, which has not considered how qualitatively different defenses might alter ecological interactions.

Linking trading ratio with TMDL (total maximum daily load) allocation matrix and uncertainty analysis.

PubMed

Zhang, H X

2008-01-01

An innovative approach for total maximum daily load (TMDL) allocation and implementation is the watershed-based pollutant trading. Given the inherent scientific uncertainty for the tradeoffs between point and nonpoint sources, setting of trading ratios can be a contentious issue and was already listed as an obstacle by several pollutant trading programs. One of the fundamental reasons that a trading ratio is often set higher (e.g. greater than 2) is to allow for uncertainty in the level of control needed to attain water quality standards, and to provide a buffer in case traded reductions are less effective than expected. However, most of the available studies did not provide an approach to explicitly address the determination of trading ratio. Uncertainty analysis has rarely been linked to determination of trading ratio.This paper presents a practical methodology in estimating "equivalent trading ratio (ETR)" and links uncertainty analysis with trading ratio determination from TMDL allocation process. Determination of ETR can provide a preliminary evaluation of "tradeoffs" between various combination of point and nonpoint source control strategies on ambient water quality improvement. A greater portion of NPS load reduction in overall TMDL load reduction generally correlates with greater uncertainty and thus requires greater trading ratio. The rigorous quantification of trading ratio will enhance the scientific basis and thus public perception for more informed decision in overall watershed-based pollutant trading program. (c) IWA Publishing 2008.

Reinforcement Learning for Constrained Energy Trading Games With Incomplete Information.

PubMed

Wang, Huiwei; Huang, Tingwen; Liao, Xiaofeng; Abu-Rub, Haitham; Chen, Guo

2017-10-01

This paper considers the problem of designing adaptive learning algorithms to seek the Nash equilibrium (NE) of the constrained energy trading game among individually strategic players with incomplete information. In this game, each player uses the learning automaton scheme to generate the action probability distribution based on his/her private information for maximizing his own averaged utility. It is shown that if one of admissible mixed-strategies converges to the NE with probability one, then the averaged utility and trading quantity almost surely converge to their expected ones, respectively. For the given discontinuous pricing function, the utility function has already been proved to be upper semicontinuous and payoff secure which guarantee the existence of the mixed-strategy NE. By the strict diagonal concavity of the regularized Lagrange function, the uniqueness of NE is also guaranteed. Finally, an adaptive learning algorithm is provided to generate the strategy probability distribution for seeking the mixed-strategy NE.

How will climate change affect spatial planning in agricultural and natural environments? Examples from three Dutch case study regions

NASA Astrophysics Data System (ADS)

Blom-Zandstra, Margaretha; Paulissen, Maurice; Agricola, Herman; Schaap, Ben

2009-11-01

Climate change will place increasing pressure on the functioning of agricultural and natural areas in the Netherlands. Strategies to adapt these areas to stress are likely to require changes in landscape structure and management. In densely populated countries such as the Netherlands, the increased pressure of climate change on agricultural and natural areas will inevitably lead, through the necessity of spatial adaptation measures, to spatial conflicts between the sectors of agriculture and nature. An integrated approach to climate change adaptation may therefore be beneficial in limiting such sectoral conflicts. We explored the conflicting and synergistic properties of different climate adaptation strategies for agricultural and natural environments in the Netherlands. To estimate the feasibility and effectiveness of the strategies, we focussed on three case study regions with contrasting landscape structural, natural and agricultural characteristics. For each region, we estimated the expected climate-related threats and associated trade-offs for arable farming and natural areas for 2040. We describe a number of spatial and integrated adaptation strategies to mitigate these threats. Formulating adaptation strategies requires consultation of different stakeholders and deliberation between different interests. We discuss some trade-offs involved in this decision-making.

The Politics of Global Value Chains: Import-dependent Firms and EU–Asia Trade Agreements

PubMed Central

Eckhardt, Jappe; Poletti, Arlo

2015-01-01

In 2006, the European Commission released its Global Europe Communication, in which it announced a shift from a multilateral to a bilateral trade strategy. One of the key pillars of this new strategy was to strengthen the bilateral trade relations with key Asian countries. In contrast to existing analyses that focus on European Union (EU) decision makers’ agency, we propose an explanation for this notable shift in the EU’s trade policy that stresses the political role of import-dependent firms. In light of the increasing integration of such firms into global value chains, the article argues that a plausible case can be made, both theoretically and empirically, that import-dependent firms had a clear stake in the signing of preferential trade agreements between the EU and Asian countries and that their lobbying efforts significantly affected the EU’s decision to start negotiations with South Korea, India and Vietnam. PMID:28018131

The Politics of Global Value Chains: Import-dependent Firms and EU-Asia Trade Agreements.

PubMed

Eckhardt, Jappe; Poletti, Arlo

2016-01-01

In 2006, the European Commission released its Global Europe Communication, in which it announced a shift from a multilateral to a bilateral trade strategy. One of the key pillars of this new strategy was to strengthen the bilateral trade relations with key Asian countries. In contrast to existing analyses that focus on European Union (EU) decision makers' agency, we propose an explanation for this notable shift in the EU's trade policy that stresses the political role of import-dependent firms. In light of the increasing integration of such firms into global value chains, the article argues that a plausible case can be made, both theoretically and empirically, that import-dependent firms had a clear stake in the signing of preferential trade agreements between the EU and Asian countries and that their lobbying efforts significantly affected the EU's decision to start negotiations with South Korea, India and Vietnam.

An Evolutionary Method for Financial Forecasting in Microscopic High-Speed Trading Environment.

PubMed

Huang, Chien-Feng; Li, Hsu-Chih

2017-01-01

The advancement of information technology in financial applications nowadays have led to fast market-driven events that prompt flash decision-making and actions issued by computer algorithms. As a result, today's markets experience intense activity in the highly dynamic environment where trading systems respond to others at a much faster pace than before. This new breed of technology involves the implementation of high-speed trading strategies which generate significant portion of activity in the financial markets and present researchers with a wealth of information not available in traditional low-speed trading environments. In this study, we aim at developing feasible computational intelligence methodologies, particularly genetic algorithms (GA), to shed light on high-speed trading research using price data of stocks on the microscopic level. Our empirical results show that the proposed GA-based system is able to improve the accuracy of the prediction significantly for price movement, and we expect this GA-based methodology to advance the current state of research for high-speed trading and other relevant financial applications.

A Diversified Investment Strategy Using Autonomous Agents

NASA Astrophysics Data System (ADS)

Barbosa, Rui Pedro; Belo, Orlando

In a previously published article, we presented an architecture for implementing agents with the ability to trade autonomously in the Forex market. At the core of this architecture is an ensemble of classification and regression models that is used to predict the direction of the price of a currency pair. In this paper, we will describe a diversified investment strategy consisting of five agents which were implemented using that architecture. By simulating trades with 18 months of out-of-sample data, we will demonstrate that data mining models can produce profitable predictions, and that the trading risk can be diminished through investment diversification.

Quantifying immediate price impact of trades based on the k-shell decomposition of stock trading networks

NASA Astrophysics Data System (ADS)

Xie, Wen-Jie; Li, Ming-Xia; Xu, Hai-Chuan; Chen, Wei; Zhou, Wei-Xing; Stanley, H. Eugene

2016-10-01

Traders in a stock market exchange stock shares and form a stock trading network. Trades at different positions of the stock trading network may contain different information. We construct stock trading networks based on the limit order book data and classify traders into k classes using the k-shell decomposition method. We investigate the influences of trading behaviors on the price impact by comparing a closed national market (A-shares) with an international market (B-shares), individuals and institutions, partially filled and filled trades, buyer-initiated and seller-initiated trades, and trades at different positions of a trading network. Institutional traders professionally use some trading strategies to reduce the price impact and individuals at the same positions in the trading network have a higher price impact than institutions. We also find that trades in the core have higher price impacts than those in the peripheral shell.

Condition-Dependent Trade-Off Between Weapon Size and Immunity in Males of the European Earwig.

PubMed

Körner, Maximilian; Vogelweith, Fanny; Foitzik, Susanne; Meunier, Joël

2017-08-11

Investigating the expression of trade-offs between key life-history functions is central to our understanding of how these functions evolved and are maintained. However, detecting trade-offs can be challenging due to variation in resource availability, which masks trade-offs at the population level. Here, we investigated in the European earwig Forficula auricularia whether (1) weapon size trades off with three key immune parameters - hemocyte concentration, phenoloxidase and prophenoloxidase activity - and whether (2) expression and strength of these trade-offs depend on male body condition (body size) and/or change after an immune challenge. Our results partially confirmed condition dependent trade-offs between weapon size and immunity in male earwigs. Specifically, we found that after an immune challenge, weapon size trades off with hemocyte concentrations in low-condition, but not in good-condition males. Contrastingly, weapon size was independent of pre-challenge hemocyte concentration. We also found no trade-off between weapon size and phenoloxidase activity, independent of body condition and immune challenge. Overall, our study reveals that trade-offs with sexual traits may weaken or disappear in good-condition individuals. Given the importance of weapon size for male reproductive success, our results highlight how low-condition individuals may employ alternative life-history investment strategies to cope with resource limitation.

Social signals and algorithmic trading of Bitcoin.

PubMed

Garcia, David; Schweitzer, Frank

2015-09-01

The availability of data on digital traces is growing to unprecedented sizes, but inferring actionable knowledge from large-scale data is far from being trivial. This is especially important for computational finance, where digital traces of human behaviour offer a great potential to drive trading strategies. We contribute to this by providing a consistent approach that integrates various datasources in the design of algorithmic traders. This allows us to derive insights into the principles behind the profitability of our trading strategies. We illustrate our approach through the analysis of Bitcoin, a cryptocurrency known for its large price fluctuations. In our analysis, we include economic signals of volume and price of exchange for USD, adoption of the Bitcoin technology and transaction volume of Bitcoin. We add social signals related to information search, word of mouth volume, emotional valence and opinion polarization as expressed in tweets related to Bitcoin for more than 3 years. Our analysis reveals that increases in opinion polarization and exchange volume precede rising Bitcoin prices, and that emotional valence precedes opinion polarization and rising exchange volumes. We apply these insights to design algorithmic trading strategies for Bitcoin, reaching very high profits in less than a year. We verify this high profitability with robust statistical methods that take into account risk and trading costs, confirming the long-standing hypothesis that trading-based social media sentiment has the potential to yield positive returns on investment.

Social signals and algorithmic trading of Bitcoin

PubMed Central

Garcia, David; Schweitzer, Frank

2015-01-01

The availability of data on digital traces is growing to unprecedented sizes, but inferring actionable knowledge from large-scale data is far from being trivial. This is especially important for computational finance, where digital traces of human behaviour offer a great potential to drive trading strategies. We contribute to this by providing a consistent approach that integrates various datasources in the design of algorithmic traders. This allows us to derive insights into the principles behind the profitability of our trading strategies. We illustrate our approach through the analysis of Bitcoin, a cryptocurrency known for its large price fluctuations. In our analysis, we include economic signals of volume and price of exchange for USD, adoption of the Bitcoin technology and transaction volume of Bitcoin. We add social signals related to information search, word of mouth volume, emotional valence and opinion polarization as expressed in tweets related to Bitcoin for more than 3 years. Our analysis reveals that increases in opinion polarization and exchange volume precede rising Bitcoin prices, and that emotional valence precedes opinion polarization and rising exchange volumes. We apply these insights to design algorithmic trading strategies for Bitcoin, reaching very high profits in less than a year. We verify this high profitability with robust statistical methods that take into account risk and trading costs, confirming the long-standing hypothesis that trading-based social media sentiment has the potential to yield positive returns on investment. PMID:26473051

Business-IT Alignment in Trade Facilitation: A Case Study

NASA Astrophysics Data System (ADS)

Adaba, Godfried; Rusu, Lazar; El-Mekawy, Mohamed

In the information age, no organization can thrive without harnessing the power of IT. The effective deployment of IT to achieve business goals and gain competitive advantage requires the alignment of business and IT strategies of organizations. Using the Strategic Alignment Maturity model, this paper evaluates strategic alignment maturity of Customs Excise Preventive service, a frontline public organization charged with trade facilitation in Ghana. Strategic alignment maturity is at level 3; which implies the existence of an established process to leverage IT for efficiency and effectiveness. Efforts are required to strengthen alignment and fully harness the potential of IT to facilitate trade in Ghana.

The potential cost savings of implementing an inter-utility NO{sub x} trading program

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

Siegel, S.; Kalagnanam, J.

1995-10-01

Technology based standards such as RACT, which require the installation of a (R)easonably (A)vailable (C)ontrol (T)echnology on a boiler by boiler basis have been the dominant factor driving electric utility NO{sub x} compliance plans. In this paper, the authors examine the cost savings of implementing NO{sub x} trading, an alternative market based strategy for reducing the emissions of nitrogen oxides (NO{sub x}) to achieve NO{sub x} reduction goals set under Title IV of the 1990 Clean Air Act. In order to estimate the potential cost savings of inter-utility NO{sub x} trading, they use a combinatorial optimization approach to identify boilermore » retrofits and operating parameters which yield efficient (i.e., the most cost effective) NO{sub x} abatement strategies. In their formulation, annual emissions at individual boilers which are expensive to abate may exceed RACT levels by up to a factor of two thus allowing for trades with boilers which can abate in a more cost effective manner. They constrain total emissions in a trading region to be at or below the level obtained had all the boilers adopted RACT. Increasing the flexibility with which trades can occur has two main effects: (1) the cost effectiveness of meeting an aggregate reduction goal increases and (2) the spatial distribution of emissions shift relative to what it would have been under a strict RACT based compliance strategy. They estimate the magnitude of these effects for two Eastern electric utilities making intra- and inter-utility NO{sub x} trades. Results indicate that the cost effectiveness of meeting RACT level reduction can be increased by as much as 38% under certain trading regimes.« less

Identifying optimum performance trade-offs using a cognitively bounded rational analysis model of discretionary task interleaving.

PubMed

Janssen, Christian P; Brumby, Duncan P; Dowell, John; Chater, Nick; Howes, Andrew

2011-01-01

We report the results of a dual-task study in which participants performed a tracking and typing task under various experimental conditions. An objective payoff function was used to provide explicit feedback on how participants should trade off performance between the tasks. Results show that participants' dual-task interleaving strategy was sensitive to changes in the difficulty of the tracking task and resulted in differences in overall task performance. To test the hypothesis that people select strategies that maximize payoff, a Cognitively Bounded Rational Analysis model was developed. This analysis evaluated a variety of dual-task interleaving strategies to identify the optimal strategy for maximizing payoff in each condition. The model predicts that the region of optimum performance is different between experimental conditions. The correspondence between human data and the prediction of the optimal strategy is found to be remarkably high across a number of performance measures. This suggests that participants were honing their behavior to maximize payoff. Limitations are discussed. Copyright © 2011 Cognitive Science Society, Inc.

Career and Technical Education Teachers' Perceptions of Culturally Diverse Classes: Rewards, Difficulties, and Useful Teaching Strategies

ERIC Educational Resources Information Center

Rehm, Marsha L.

2008-01-01

The purpose of this study was to identify CTE teachers' perceptions of selected rewards, difficulties, and useful teaching strategies in culturally diverse classes. The sample was comprised of 41 trade and industrial, business technology, and family and consumer sciences teachers who taught students from 30 cultural backgrounds. The data were…

Optimal trading from minimizing the period of bankruptcy risk

NASA Astrophysics Data System (ADS)

Liehr, S.; Pawelzik, K.

2001-04-01

Assuming that financial markets behave similar to random walk processes we derive a trading strategy with variable investment which is based on the equivalence of the period of bankruptcy risk and the risk to profit ratio. We define a state dependent predictability measure which can be attributed to the deterministic and stochastic components of the price dynamics. The influence of predictability variations and especially of short term inefficiency structures on the optimal amount of investment is analyzed in the given context and a method for adaptation of a trading system to the proposed objective function is presented. Finally we show the performance of our trading strategy on the DAX and S&P 500 as examples for real world data using different types of prediction models in comparison.

Network structure impacts global commodity trade growth and resilience.

PubMed

Kharrazi, Ali; Rovenskaya, Elena; Fath, Brian D

2017-01-01

Global commodity trade networks are critical to our collective sustainable development. Their increasing interconnectedness pose two practical questions: (i) Do the current network configurations support their further growth? (ii) How resilient are these networks to economic shocks? We analyze the data of global commodity trade flows from 1996 to 2012 to evaluate the relationship between structural properties of the global commodity trade networks and (a) their dynamic growth, as well as (b) the resilience of their growth with respect to the 2009 global economic shock. Specifically, we explore the role of network efficiency and redundancy using the information theory-based network flow analysis. We find that, while network efficiency is positively correlated with growth, highly efficient systems appear to be less resilient, losing more and gaining less growth following an economic shock. While all examined networks are rather redundant, we find that network redundancy does not hinder their growth. Moreover, systems exhibiting higher levels of redundancy lose less and gain more growth following an economic shock. We suggest that a strategy to support making global trade networks more efficient via, e.g., preferential trade agreements and higher specialization, can promote their further growth; while a strategy to increase the global trade networks' redundancy via e.g., more abundant free-trade agreements, can improve their resilience to global economic shocks.

Network structure impacts global commodity trade growth and resilience

PubMed Central

Rovenskaya, Elena; Fath, Brian D.

2017-01-01

Global commodity trade networks are critical to our collective sustainable development. Their increasing interconnectedness pose two practical questions: (i) Do the current network configurations support their further growth? (ii) How resilient are these networks to economic shocks? We analyze the data of global commodity trade flows from 1996 to 2012 to evaluate the relationship between structural properties of the global commodity trade networks and (a) their dynamic growth, as well as (b) the resilience of their growth with respect to the 2009 global economic shock. Specifically, we explore the role of network efficiency and redundancy using the information theory-based network flow analysis. We find that, while network efficiency is positively correlated with growth, highly efficient systems appear to be less resilient, losing more and gaining less growth following an economic shock. While all examined networks are rather redundant, we find that network redundancy does not hinder their growth. Moreover, systems exhibiting higher levels of redundancy lose less and gain more growth following an economic shock. We suggest that a strategy to support making global trade networks more efficient via, e.g., preferential trade agreements and higher specialization, can promote their further growth; while a strategy to increase the global trade networks’ redundancy via e.g., more abundant free-trade agreements, can improve their resilience to global economic shocks. PMID:28207790

Profitability of simple technical trading rules of Chinese stock exchange indexes

NASA Astrophysics Data System (ADS)

Zhu, Hong; Jiang, Zhi-Qiang; Li, Sai-Ping; Zhou, Wei-Xing

2015-12-01

Although technical trading rules have been widely used by practitioners in financial markets, their profitability still remains controversial. We here investigate the profitability of moving average (MA) and trading range break (TRB) rules by using the Shanghai Stock Exchange Composite Index (SHCI) from May 21, 1992 through December 31, 2013 and Shenzhen Stock Exchange Component Index (SZCI) from April 3, 1991 through December 31, 2013. The t-test is adopted to check whether the mean returns which are conditioned on the trading signals are significantly different from unconditioned returns and whether the mean returns conditioned on the buy signals are significantly different from the mean returns conditioned on the sell signals. We find that TRB rules outperform MA rules and short-term variable moving average (VMA) rules outperform long-term VMA rules. By applying White's Reality Check test and accounting for the data snooping effects, we find that the best trading rule outperforms the buy-and-hold strategy when transaction costs are not taken into consideration. Once transaction costs are included, trading profits will be eliminated completely. Our analysis suggests that simple trading rules like MA and TRB cannot beat the standard buy-and-hold strategy for the Chinese stock exchange indexes.

Multidisciplinary studies of wildlife trade in primates: Challenges and priorities.

PubMed

Blair, Mary E; Le, Minh D; Sterling, Eleanor J

2017-11-01

Wildlife trade is increasingly recognized as an unsustainable threat to primate populations and informing its management is a growing focus and application of primatological research. However, management policies based on ecological research alone cannot address complex socioeconomic or cultural contexts as drivers of wildlife trade. Multidisciplinary research is required to understand trade complexity and identify sustainable management strategies. Here, we define multidisciplinary research as research that combines more than one academic discipline, and highlight how the articles in this issue combine methods and approaches to fill key gaps and offer a more comprehensive understanding of underlying drivers of wildlife trade including consumer demand, enforcement patterns, source population status, and accessibility of targeted species. These articles also focus on how these drivers interact at different scales, how trade patterns relate to ethics, and the potential effectiveness of different policy interventions in reducing wildlife trade. We propose priorities for future research on primate trade including expanding from multidisciplinary to interdisciplinary research questions and approaches co-created by research teams that integrate across different disciplines such as cultural anthropology, ecology, economics, and public policy. We also discuss challenges that limit the integration of information across disciplines to meet these priorities. © 2017 Wiley Periodicals, Inc.

Volatility measurement with directional change in Chinese stock market: Statistical property and investment strategy

NASA Astrophysics Data System (ADS)

Ma, Junjun; Xiong, Xiong; He, Feng; Zhang, Wei

2017-04-01

The stock price fluctuation is studied in this paper with intrinsic time perspective. The event, directional change (DC) or overshoot, are considered as time scale of price time series. With this directional change law, its corresponding statistical properties and parameter estimation is tested in Chinese stock market. Furthermore, a directional change trading strategy is proposed for invest in the market portfolio in Chinese stock market, and both in-sample and out-of-sample performance are compared among the different method of model parameter estimation. We conclude that DC method can capture important fluctuations in Chinese stock market and gain profit due to the statistical property that average upturn overshoot size is bigger than average downturn directional change size. The optimal parameter of DC method is not fixed and we obtained 1.8% annual excess return with this DC-based trading strategy.

Excessive trading, a gambling disorder in its own right? A case study on a French disordered gamblers cohort.

PubMed

Grall-Bronnec, Marie; Sauvaget, Anne; Boutin, Claude; Bulteau, Samuel; Jiménez-Murcia, Susana; Fernández-Aranda, Fernando; Challet-Bouju, Gaëlle; Caillon, Julie

2017-01-01

Trading and gambling appear to share some similarities. Indeed, traders can get professionally involved in high-risk types of trading as if it were gambling. This research explores whether excessive trading can be conceptualized as a subset of gambling disorders. To better acknowledge the existence of an addictive-like trading behavior and to discuss its phenomenological similarities with gambling disorders. The data of 8 excessive traders out of a cohort of 221 outpatients seeking treatment in our Problem Gambling unit were analyzed. Our case series revealed important similarities with gambling disorders in terms of diagnosis, trajectory and comorbidities. Like many disordered gamblers, excessive traders of this study experienced a number of small early wins, chased their losses, and ended up losing control over the money they invested. All of them invested in very risky stocks associated with short-term trading leading to potential large gains, but also with very significant losses. The structure itself of the two activities (gambling and trading) is very close. Our results tended to support the idea of an addictive-like trading behavior as a subset of gambling disorders. Investing is not a form of gambling, but some people gamble with investments. Several observations and recommendations can be made: (i) conduct researches; (ii) build and validate specific assessment tools; (iii) develop strategies for prevention and treatment; and (iv) conduct more rigorous studies to clarify what we named an addictive-like trading behavior. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Improving decision speed, accuracy and group cohesion through early information gathering in house-hunting ants.

PubMed

Stroeymeyt, Nathalie; Giurfa, Martin; Franks, Nigel R

2010-09-29

Successful collective decision-making depends on groups of animals being able to make accurate choices while maintaining group cohesion. However, increasing accuracy and/or cohesion usually decreases decision speed and vice-versa. Such trade-offs are widespread in animal decision-making and result in various decision-making strategies that emphasize either speed or accuracy, depending on the context. Speed-accuracy trade-offs have been the object of many theoretical investigations, but these studies did not consider the possible effects of previous experience and/or knowledge of individuals on such trade-offs. In this study, we investigated how previous knowledge of their environment may affect emigration speed, nest choice and colony cohesion in emigrations of the house-hunting ant Temnothorax albipennis, a collective decision-making process subject to a classical speed-accuracy trade-off. Colonies allowed to explore a high quality nest site for one week before they were forced to emigrate found that nest and accepted it faster than emigrating naïve colonies. This resulted in increased speed in single choice emigrations and higher colony cohesion in binary choice emigrations. Additionally, colonies allowed to explore both high and low quality nest sites for one week prior to emigration remained more cohesive, made more accurate decisions and emigrated faster than emigrating naïve colonies. These results show that colonies gather and store information about available nest sites while their nest is still intact, and later retrieve and use this information when they need to emigrate. This improves colony performance. Early gathering of information for later use is therefore an effective strategy allowing T. albipennis colonies to improve simultaneously all aspects of the decision-making process--i.e. speed, accuracy and cohesion--and partly circumvent the speed-accuracy trade-off classically observed during emigrations. These findings should be taken into account in future studies on speed-accuracy trade-offs.

Indoor Air Quality and Energy Efficiency

EPA Pesticide Factsheets

EPA completed an extensive modeling study to assess the compatibilities and trade-offs between energy, indoor air quality, and thermal comfort objectives for HVAC systems and to formulate strategies for superior performance across all areas.

Evolution of resistance and tolerance to herbivores: testing the trade-off hypothesis.

PubMed

Kariñho-Betancourt, Eunice; Núñez-Farfán, Juan

2015-01-01

Background. To cope with their natural enemies, plants rely on resistance and tolerance as defensive strategies. Evolution of these strategies among natural population can be constrained by the absence of genetic variation or because of the antagonistic genetic correlation (trade-off) between them. Also, since plant defenses are integrated by several traits, it has been suggested that trade-offs might occur between specific defense traits. Methodology/Principal Findings. We experimentally assessed (1) the presence of genetic variance in tolerance, total resistance, and leaf trichome density as specific defense trait, (2) the extent of natural selection acting on plant defenses, and (3) the relationship between total resistance and leaf trichome density with tolerance to herbivory in the annual herb Datura stramonium. Full-sib families of D. stramonium were either exposed to natural herbivores (control) or protected from them by a systemic insecticide. We detected genetic variance for leaf trichome density, and directional selection acting on this character. However, we did not detect a negative significant correlation between tolerance and total resistance, or between tolerance and leaf trichome density. We argue that low levels of leaf damage by herbivores precluded the detection of a negative genetic correlation between plant defense strategies. Conclusions/Significance. This study provides empirical evidence of the independent evolution of plant defense strategies, and a defensive role of leaf trichomes. The pattern of selection should favor individuals with high trichomes density. Also, because leaf trichome density reduces damage by herbivores and possess genetic variance in the studied population, its evolution is not constrained.

Evolution of resistance and tolerance to herbivores: testing the trade-off hypothesis

PubMed Central

Kariñho-Betancourt, Eunice

2015-01-01

Background. To cope with their natural enemies, plants rely on resistance and tolerance as defensive strategies. Evolution of these strategies among natural population can be constrained by the absence of genetic variation or because of the antagonistic genetic correlation (trade-off) between them. Also, since plant defenses are integrated by several traits, it has been suggested that trade-offs might occur between specific defense traits. Methodology/Principal Findings. We experimentally assessed (1) the presence of genetic variance in tolerance, total resistance, and leaf trichome density as specific defense trait, (2) the extent of natural selection acting on plant defenses, and (3) the relationship between total resistance and leaf trichome density with tolerance to herbivory in the annual herb Datura stramonium. Full-sib families of D. stramonium were either exposed to natural herbivores (control) or protected from them by a systemic insecticide. We detected genetic variance for leaf trichome density, and directional selection acting on this character. However, we did not detect a negative significant correlation between tolerance and total resistance, or between tolerance and leaf trichome density. We argue that low levels of leaf damage by herbivores precluded the detection of a negative genetic correlation between plant defense strategies. Conclusions/Significance. This study provides empirical evidence of the independent evolution of plant defense strategies, and a defensive role of leaf trichomes. The pattern of selection should favor individuals with high trichomes density. Also, because leaf trichome density reduces damage by herbivores and possess genetic variance in the studied population, its evolution is not constrained. PMID:25780756

Bubbles, shocks and elementary technical trading strategies

NASA Astrophysics Data System (ADS)

Fry, John

2014-01-01

In this paper we provide a unifying framework for a set of seemingly disparate models for bubbles, shocks and elementary technical trading strategies in financial markets. Markets operate by balancing intrinsic levels of risk and return. This seemingly simple observation is commonly over-looked by academics and practitioners alike. Our model shares its origins in statistical physics with others. However, under our approach, changes in market regime can be explicitly shown to represent a phase transition from random to deterministic behaviour in prices. This structure leads to an improved physical and econometric model. We develop models for bubbles, shocks and elementary technical trading strategies. The list of empirical applications is both interesting and topical and includes real-estate bubbles and the on-going Eurozone crisis. We close by comparing the results of our model with purely qualitative findings from the finance literature.

Prospect Theory for Online Financial Trading

PubMed Central

Martino, Mauro; Altshuler, Yaniv

2014-01-01

Prospect theory is widely viewed as the best available descriptive model of how people evaluate risk in experimental settings. According to prospect theory, people are typically risk-averse with respect to gains and risk-seeking with respect to losses, known as the “reflection effect”. People are much more sensitive to losses than to gains of the same magnitude, a phenomenon called “loss aversion”. Despite of the fact that prospect theory has been well developed in behavioral economics at the theoretical level, there exist very few large-scale empirical studies and most of the previous studies have been undertaken with micro-panel data. Here we analyze over 28.5 million trades made by 81.3 thousand traders of an online financial trading community over 28 months, aiming to explore the large-scale empirical aspect of prospect theory. By analyzing and comparing the behavior of winning and losing trades and traders, we find clear evidence of the reflection effect and the loss aversion phenomenon, which are essential in prospect theory. This work hence demonstrates an unprecedented large-scale empirical evidence of prospect theory, which has immediate implication in financial trading, e.g., developing new trading strategies by minimizing the impact of the reflection effect and the loss aversion phenomenon. Moreover, we introduce three novel behavioral metrics to differentiate winning and losing traders based on their historical trading behavior. This offers us potential opportunities to augment online social trading where traders are allowed to watch and follow the trading activities of others, by predicting potential winners based on their historical trading behavior. PMID:25330203

Prospect theory for online financial trading.

PubMed

Liu, Yang-Yu; Nacher, Jose C; Ochiai, Tomoshiro; Martino, Mauro; Altshuler, Yaniv

2014-01-01

Prospect theory is widely viewed as the best available descriptive model of how people evaluate risk in experimental settings. According to prospect theory, people are typically risk-averse with respect to gains and risk-seeking with respect to losses, known as the "reflection effect". People are much more sensitive to losses than to gains of the same magnitude, a phenomenon called "loss aversion". Despite of the fact that prospect theory has been well developed in behavioral economics at the theoretical level, there exist very few large-scale empirical studies and most of the previous studies have been undertaken with micro-panel data. Here we analyze over 28.5 million trades made by 81.3 thousand traders of an online financial trading community over 28 months, aiming to explore the large-scale empirical aspect of prospect theory. By analyzing and comparing the behavior of winning and losing trades and traders, we find clear evidence of the reflection effect and the loss aversion phenomenon, which are essential in prospect theory. This work hence demonstrates an unprecedented large-scale empirical evidence of prospect theory, which has immediate implication in financial trading, e.g., developing new trading strategies by minimizing the impact of the reflection effect and the loss aversion phenomenon. Moreover, we introduce three novel behavioral metrics to differentiate winning and losing traders based on their historical trading behavior. This offers us potential opportunities to augment online social trading where traders are allowed to watch and follow the trading activities of others, by predicting potential winners based on their historical trading behavior.

Emissions trading comes of age as a strategic tool

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

Pospisil, R.

1996-03-01

Trading of emissions credits has quickly evolved from a curiosity to a viable compliance strategy for electric utilities and power-generating industrial firms. A sure sign that emissions trading has matured is the entry of power marketers onto the scene; in bundling pollution allowances with their electricity offerings, they are making their product more attractive - and stealing a page from the coal companies` strategy book to boot. Although most current activity involves credits for sulfur dioxide (SO{sub 2}), nitrogen oxide (NO{sub x}) trading is under way in certain areas as well, although NO{sub x} markets are local and thus slowermore » to develop. However, utilities see economic development potential in this area; some are providing NO{sub x} credits to their industrial customers to help them comply with environmental regulations - and to retain their loyalty when deregulation affords them a choice of electricity suppliers. This paper briefly discusses the issues related to emissions trading.« less

Century of the Seas: Unlocking Indian Maritime Strategy in the 21st Century

DTIC Science & Technology

2017-09-01

Ensuring Secure Seas. Finally, this thesis examines India’s economic policies, specifically maritime trade, as well as domestic politics, to see how...they engage and shape Indian maritime strategy. These findings present a combined analysis of economic , security, and political factors mentioned above...Ensuring Secure Seas. Finally, this thesis examines India’s economic policies, specifically maritime trade, as well as domestic politics, to see how

Customs Service Modernization: Impact of New Trade Compliance Strategy Needs to Be Assessed.

DTIC Science & Technology

1999-12-01

The Mod Act fundamentally altered the relationship between importers and Customs by shifting from Customs to the importer the legal responsibility...New Trade Compliance Strategy B-280470 • account management : Customs ’ approach to managing its work through accounts (importing companies) rather...assessment, account management , and Customs ’ responses to noncompliant importers have been implemented but have not yet reached many of the intended

Hedges Used in Business Emails: A Corpus Study on the Language Strategy of International Business Communication Online

ERIC Educational Resources Information Center

Yue, Siwei; Wang, Xuefei

2014-01-01

Based on a corpus of 296 authentic business emails produced in computer-mediated business communication from 7 Chinese international trade enterprises, this paper addresses the language strategy applied in CMC (Computer-mediated Communication) by examining the use of hedges. With the emergence of internet, a wider range of hedges are applied…

Profiting from competition: Financial tools for electric generation companies

NASA Astrophysics Data System (ADS)

Richter, Charles William, Jr.

Regulations governing the operation of electric power systems in North America and many other areas of the world are undergoing major changes designed to promote competition. This process of change is often referred to as deregulation. Participants in deregulated electricity systems may find that their profits will greatly benefit from the implementation of successful bidding strategies. While the goal of the regulators may be to create rules which balance reliable power system operation with maximization of the total benefit to society, the goal of generation companies is to maximize their profit, i.e., return to their shareholders. The majority of the research described here is conducted from the point of view of generation companies (GENCOs) wishing to maximize their expected utility function, which is generally comprised of expected profit and risk. Strategies that help a GENCO to maximize its objective function must consider the impact of (and aid in making) operating decisions that may occur within a few seconds to multiple years. The work described here assumes an environment in which energy service companies (ESCOs) buy and GENCOs sell power via double auctions in regional commodity exchanges. Power is transported on wires owned by transmission companies (TRANSCOs) and distribution companies (DISTCOs). The proposed market framework allows participants to trade electrical energy contracts via the spot, futures, options, planning, and swap markets. An important method of studying these proposed markets and the behavior of participating agents is the field of experimental/computational economics. For much of the research reported here, the market simulator developed by Kumar and Sheble and similar simulators has been adapted to allow computerized agents to trade energy. Creating computerized agents that can react as rationally or irrationally as a human trader is a difficult problem for which we have turned to the field of artificial intelligence. Some of our work uses GP-Automata, a technique which combines genetic programming and finite state machines, to represent adaptive agents. We use a genetic algorithm to evolve these adaptive agents (each with its own bidding strategy) for use in a double auction. The agent's strategies may be judged by the amount of profit they produce and are tested by computerized agents repeatedly buying and selling electricity in an auction simulator. In addition to the obvious profit-maximization strategies, one can also design strategies which exhibit other types of trading behaviors. The resulting strategies can be used directly in on-line trading, or as realistic models of competitors in a trading simulator. In addition to developing double auction bidding strategies, we investigate and discuss methods of an energy trader's risk. This can be done using such financial vehicles as futures and options contracts or through the inclusion of risk while judging strategies used in the market simulations described above. We discuss the role of fuzzy logic in the competitive electric marketplace, including how it can be applied in developing bidding strategies. Since competition promises to drive the power system closer to its operating limits, improvements in measurement and system control will be important. We provide an example of using fuzzy logic to do automatic generation control and discuss extensions that would make it superior to traditional controllers. Since the GENCO's forte is primarily generating electricity, we examine unit commitment and discuss how to update it for the competitive environment. We discuss the role of unit commitment in developing bidding strategies, as well as, the role of bidding strategies in solving the unit commitment problem. Depending on the market structure adopted by a particular location, large amounts of bidding data may be available to regulators or market participants. Ideally, regulators could use this data to verify dig the market is efficient. Market participants with access to this data might gain an advantage over their competitors if they could somehow determine their competitor's bidding strategy. We outline methods of automatically inferring other participants' trading rules based on historical data. Much of the work described here should aid in the design of effective operating procedures, trading strategies and profitable portfolios for energy producers.

Dynamic Portfolio Strategy Using Clustering Approach

PubMed Central

Lu, Ya-Nan; Li, Sai-Ping; Jiang, Xiong-Fei; Zhong, Li-Xin; Qiu, Tian

2017-01-01

The problem of portfolio optimization is one of the most important issues in asset management. We here propose a new dynamic portfolio strategy based on the time-varying structures of MST networks in Chinese stock markets, where the market condition is further considered when using the optimal portfolios for investment. A portfolio strategy comprises two stages: First, select the portfolios by choosing central and peripheral stocks in the selection horizon using five topological parameters, namely degree, betweenness centrality, distance on degree criterion, distance on correlation criterion and distance on distance criterion. Second, use the portfolios for investment in the investment horizon. The optimal portfolio is chosen by comparing central and peripheral portfolios under different combinations of market conditions in the selection and investment horizons. Market conditions in our paper are identified by the ratios of the number of trading days with rising index to the total number of trading days, or the sum of the amplitudes of the trading days with rising index to the sum of the amplitudes of the total trading days. We find that central portfolios outperform peripheral portfolios when the market is under a drawup condition, or when the market is stable or drawup in the selection horizon and is under a stable condition in the investment horizon. We also find that peripheral portfolios gain more than central portfolios when the market is stable in the selection horizon and is drawdown in the investment horizon. Empirical tests are carried out based on the optimal portfolio strategy. Among all possible optimal portfolio strategies based on different parameters to select portfolios and different criteria to identify market conditions, 65% of our optimal portfolio strategies outperform the random strategy for the Shanghai A-Share market while the proportion is 70% for the Shenzhen A-Share market. PMID:28129333

Dynamic Portfolio Strategy Using Clustering Approach.

PubMed

Ren, Fei; Lu, Ya-Nan; Li, Sai-Ping; Jiang, Xiong-Fei; Zhong, Li-Xin; Qiu, Tian

2017-01-01

The problem of portfolio optimization is one of the most important issues in asset management. We here propose a new dynamic portfolio strategy based on the time-varying structures of MST networks in Chinese stock markets, where the market condition is further considered when using the optimal portfolios for investment. A portfolio strategy comprises two stages: First, select the portfolios by choosing central and peripheral stocks in the selection horizon using five topological parameters, namely degree, betweenness centrality, distance on degree criterion, distance on correlation criterion and distance on distance criterion. Second, use the portfolios for investment in the investment horizon. The optimal portfolio is chosen by comparing central and peripheral portfolios under different combinations of market conditions in the selection and investment horizons. Market conditions in our paper are identified by the ratios of the number of trading days with rising index to the total number of trading days, or the sum of the amplitudes of the trading days with rising index to the sum of the amplitudes of the total trading days. We find that central portfolios outperform peripheral portfolios when the market is under a drawup condition, or when the market is stable or drawup in the selection horizon and is under a stable condition in the investment horizon. We also find that peripheral portfolios gain more than central portfolios when the market is stable in the selection horizon and is drawdown in the investment horizon. Empirical tests are carried out based on the optimal portfolio strategy. Among all possible optimal portfolio strategies based on different parameters to select portfolios and different criteria to identify market conditions, 65% of our optimal portfolio strategies outperform the random strategy for the Shanghai A-Share market while the proportion is 70% for the Shenzhen A-Share market.

Optimising import risk mitigation: anticipating the unintended consequences and competing risks of informal trade.

PubMed

Hueston, W; Travis, D; van Klink, E

2011-04-01

The effectiveness of risk mitigation may be compromised by informal trade, including illegal activities, parallel markets and extra-legal activities. While no regulatory system is 100% effective in eliminating the risk of disease transmission through animal and animal product trade, extreme risk aversion in formal import health regulations may increase informal trade, with the unintended consequence of creating additional risks outside regulatory purview. Optimal risk mitigation on a national scale requires scientifically sound yet flexible mitigation strategies that can address the competing risks of formal and informal trade. More robust risk analysis and creative engagement of nontraditional partners provide avenues for addressing informal trade.

An Evolutionary Method for Financial Forecasting in Microscopic High-Speed Trading Environment

PubMed Central

Li, Hsu-Chih

2017-01-01

The advancement of information technology in financial applications nowadays have led to fast market-driven events that prompt flash decision-making and actions issued by computer algorithms. As a result, today's markets experience intense activity in the highly dynamic environment where trading systems respond to others at a much faster pace than before. This new breed of technology involves the implementation of high-speed trading strategies which generate significant portion of activity in the financial markets and present researchers with a wealth of information not available in traditional low-speed trading environments. In this study, we aim at developing feasible computational intelligence methodologies, particularly genetic algorithms (GA), to shed light on high-speed trading research using price data of stocks on the microscopic level. Our empirical results show that the proposed GA-based system is able to improve the accuracy of the prediction significantly for price movement, and we expect this GA-based methodology to advance the current state of research for high-speed trading and other relevant financial applications. PMID:28316618

Trade-offs between reproductive allocation and storage in species of Oenothera L. (Onagraceae) native to Argentina

NASA Astrophysics Data System (ADS)

Vilela, Alejandra; Cariaga, Rodrigo; González-Paleo, Luciana; Ravetta, Damián

2008-01-01

A trade-off between reproduction and survival arises because current reproduction diminishes levels of a limiting resource such that less can be placed in storage organs for the survival of an organism during the unfavorable season. Oenothera is a particularly suited genus for studying those kind of trade-offs because it contains species with different life-history strategies (annual, biennial and perennial). Since allocation to leaves is a major factor associated with changes in life-history, here we tested the hypothesis that Oenothera leaf attributes would affect plant reproductive effort and therefore, root reserves. We selected two groups of taxa differing in their leaf area ratio (low- and high-LAR) and we compared their pattern of resource allocation to growth, reproduction and storage. Path analysis confirmed our hypothesis that LAR is the most important variable in explaining variation in allocation to reproduction or storage. The group with high allocation to leaves assigned resources preferentially to storage while the other group allocated more resources to reproduction, as predicted. A trade-off between reproduction and storage was only confirmed for the high-LAR group. The low-LAR group showed the life-history tactic of annual plants, while the high-LAR group exhibited a strategy generally associated with perenniality.

Evolution, the loss of diversity and the role of trade-offs.

PubMed

Best, Alex; Bowers, Roger; White, Andy

2015-06-01

We investigate how the loss of previously evolved diversity in host resistance to disease is dependent on the complexity of the underlying evolutionary trade-off. Working within the adaptive dynamics framework, using graphical tools (pairwise invasion plots, PIPs; trait evolution plots, TEPs) and algebraic analysis we consider polynomial trade-offs of increasing degree. Our focus is on the evolutionary trajectory of the dimorphic population after it has been attracted to an evolutionary branching point. We show that for sufficiently complex trade-offs (here, polynomials of degree three or higher) the resulting invasion boundaries can form closed 'oval' areas of invadability and strategy coexistence. If no attracting singular strategies exist within this region, then the population is destined to evolve outside of the region of coexistence, resulting in the loss of one strain. In particular, the loss of diversity in this model always occurs in such a way that the remaining strain is not attracted back to the branching point but to an extreme of the trade-off, meaning the diversity is lost forever. We also show similar results for a non-polynomial but complex trade-off, and for a different eco-evolutionary model. Our work further highlights the importance of trade-offs to evolutionary behaviour. Copyright © 2015 Elsevier Inc. All rights reserved.

Life-history trade-offs mediate 'personality' variation in two colour morphs of the pea aphid, Acyrthosiphon pisum.

PubMed

Schuett, Wiebke; Dall, Sasha R X; Kloesener, Michaela H; Baeumer, Jana; Beinlich, Felix; Eggers, Till

2015-01-01

Life-history trade-offs are considered a major driving force in the emergence of consistent behavioural differences (personality variation); but empirical tests are scarce. We investigated links between a personality trait (escape response), life-history and state variables (growth rate, size and age at first reproduction, age-dependent reproductive rates, lifetime reproductive success, life span) in red and green colour morphs of clonal pea aphids, Acyrthosiphon pisum. Escape response (dropping/non-dropping off a plant upon a predatory attack) was measured repeatedly to classify individuals as consistent droppers, consistent nondroppers or inconsistents. Red morphs experienced stronger trade-offs between early reproduction and life span than green morphs; and red consistent (non)droppers had highest lifetime reproductive success. Red droppers followed a risk-averse life-history strategy (high late reproduction), red nondroppers a risk-prone strategy (high early reproduction), while reproductive rates were equivalent for all green behavioural types and red inconsistents. This suggests that red morphs suffer the highest costs of dropping (they are most conspicuous to predators), which 'equivalates' fitness payoffs to both risk-takers (red non-droppers) and risk-averse red droppers. The strong trade-off also means that committing to a particular lifestyle (being consistent) maximises fitness. Our study suggests that life-history trade-offs likely mediate personality variation but effects might depend on interactions with other organismal characteristics (here: colour morph). © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

Canada-U.S. Border Air Quality Strategy Border Reports

EPA Pesticide Factsheets

View reports on two airshed pilot studies that explored the human health effects of air pollution in the United States and Canada, plus a report on the feasibility of transboundary emissions cap and trade program.

Cuckoos, cowbirds and hosts: adaptations, trade-offs and constraints.

PubMed

Krüger, Oliver

2007-10-29

The interactions between brood parasitic birds and their host species provide one of the best model systems for coevolution. Despite being intensively studied, the parasite-host system provides ample opportunities to test new predictions from both coevolutionary theory as well as life-history theory in general. I identify four main areas that might be especially fruitful: cuckoo female gentes as alternative reproductive strategies, non-random and nonlinear risks of brood parasitism for host individuals, host parental quality and targeted brood parasitism, and differences and similarities between predation risk and parasitism risk. Rather than being a rare and intriguing system to study coevolutionary processes, I believe that avian brood parasites and their hosts are much more important as extreme cases in the evolution of life-history strategies. They provide unique examples of trade-offs and situations where constraints are either completely removed or particularly severe.

Prospect Theory for Online Financial Trading

NASA Astrophysics Data System (ADS)

Liu, Yang-Yu; Nacher, Jose C.; Ochiai, Tomoshiro; Martino, Mauro; Altshuler, Yaniv

2014-03-01

Prospect theory is widely viewed as the best available descriptive model of how people evaluate risk in experimental settings. According to prospect theory, people make decisions based on the potential value of losses and gains rather than the final outcome. People are risk-averse with respect to gains and risk-seeking with respect to losses, a phenomenon called ``loss aversion''. Despite of the fact that prospect theory has been well studied in behavioral economics at the theoretical level, there exist very few empirical research and most of them has been undertaken with micro-panel data. Here we analyze the trading activities of over 1.5 million members of an online financial trading community over 28 months, aiming to explore the large-scale empirical aspect of prospect theory. By analyzing and comparing the behaviour of ``winners'' and ``losers'', i.e., traders with positive or negative final net profit, we find clear evidence of the loss aversion phenomenon, an essence in prospect theory. This work demonstrates an unprecedented large-scale empirical evidence of prospect theory. It has immediate implication in financial trading, e.g., developing new trading strategies by minimizing the effect of loss aversion. It also provides opportunity to augment online social trading, where users are allowed to watch and follow the trading activity of others, by predicting potential winners based on their historical trading behaviour.

Trade Books in the Mathematics Classroom: The Impact of Many, Varied Perspectives on Determinations of Quality

ERIC Educational Resources Information Center

Nesmith, Suzanne; Cooper, Sandi

2010-01-01

The integration of children's trade books in the mathematics classroom has experienced a dramatic surge in its popularity; yet, though the positive benefits of this strategy have been well documented, these benefits may only be realized if the literature is of high quality. Utilizing a mathematics trade book evaluation instrument, this inquiry…

Optimal defense strategies in an idealized microbial food web under trade-off between competition and defense.

PubMed

Våge, Selina; Storesund, Julia E; Giske, Jarl; Thingstad, T Frede

2014-01-01

Trophic mechanisms that can generate biodiversity in food webs include bottom-up (growth rate regulating) and top-down (biomass regulating) factors. The top-down control has traditionally been analyzed using the concepts of "Keystone Predation" (KP) and "Killing-the-Winner" (KtW), predominately occuring in discussions of macro- and micro-biological ecology, respectively. Here we combine the classical diamond-shaped food web structure frequently discussed in KP analyses and the KtW concept by introducing a defense strategist capable of partial defense. A formalized description of a trade-off between the defense-strategist's competitive and defensive ability is included. The analysis reveals a complex topology of the steady state solution with strong relationships between food web structure and the combination of trade-off, defense strategy and the system's nutrient content. Among the results is a difference in defense strategies corresponding to maximum biomass, production, or net growth rate of invading individuals. The analysis thus summons awareness that biomass or production, parameters typically measured in field studies to infer success of particular biota, are not directly acted upon by natural selection. Under coexistence with a competition specialist, a balance of competitive and defensive ability of the defense strategist was found to be evolutionarily stable, whereas stronger defense was optimal under increased nutrient levels in the absence of the pure competition specialist. The findings of success of different defense strategies are discussed with respect to SAR11, a highly successful bacterial clade in the pelagic ocean.

Analysis of swine movements in a province in Northern Vietnam and application in the design of surveillance strategies for infectious diseases

PubMed Central

Baudon, Eugénie; Fournié, Guillaume; Hiep, Dao Thi; Pham, Thi Thanh Hoa; Duboz, Raphael; Gély, Marie; Peiris, Malik; Cowling, Benjamin J.; Ton, Vu Dinh; Peyre, Marisa

2015-01-01

Summary While swine production is rapidly growing in South-East Asia, the structure of the swine industry and the dynamic of pig movements have not been well-studied. However, this knowledge is a pre-requisite for understanding the dynamic of disease transmission in swine populations and designing cost-effective surveillance strategies for infectious diseases. In this study, we assessed the farming and trading practices in the Vietnamese swine familial farming sector, which accounts for most pigs in Vietnam, and for which disease surveillance is a major challenge. Farmers from two communes of a Red River Delta province (Northern Vietnam) were interviewed, along with traders involved in pig transactions. Major differences in the trade structure were observed between the two communes. One commune had mainly transversal trades, i.e. between farms of equivalent sizes, whereas the other had pyramidal trades, i.e. from larger to smaller farms. Companies and large familial farrow-to-finish farms were likely to act as major sources of disease spread through pig sales, demonstrating their importance for disease control. Familial fattening farms with high pig purchases were at greater risk of disease introduction and should be targeted for disease detection as part of a risk-based surveillance. In contrast, many other familial farms were isolated or weakly connected to the swine trade network limiting their relevance for surveillance activities. However, some of these farms used boar hiring for breeding, increasing the risk of disease spread. Most familial farms were slaughtering pigs at the farm or in small local slaughterhouses, making the surveillance at the slaughterhouse inefficient. In terms of spatial distribution of the trades, the results suggested that Northern provinces were highly connected and showed some connection with Central and Southern provinces. These results are useful to develop risk-based surveillance protocols for disease detection in the swine familial sector, and to make recommendations for disease control. PMID:26040303

Analysis of Swine Movements in a Province in Northern Vietnam and Application in the Design of Surveillance Strategies for Infectious Diseases.

PubMed

Baudon, E; Fournié, G; Hiep, D T; Pham, T T H; Duboz, R; Gély, M; Peiris, M; Cowling, B J; Ton, V D; Peyre, M

2017-04-01

While swine production is rapidly growing in South-East Asia, the structure of the swine industry and the dynamic of pig movements have not been well-studied. However, this knowledge is a prerequisite for understanding the dynamic of disease transmission in swine populations and designing cost-effective surveillance strategies for infectious diseases. In this study, we assessed the farming and trading practices in the Vietnamese swine familial farming sector, which accounts for most pigs in Vietnam, and for which disease surveillance is a major challenge. Farmers from two communes of a Red River Delta Province (northern Vietnam) were interviewed, along with traders involved in pig transactions. Major differences in the trade structure were observed between the two communes. One commune had mainly transversal trades, that is between farms of equivalent sizes, whereas the other had pyramidal trades, that is from larger to smaller farms. Companies and large familial farrow-to-finish farms were likely to act as major sources of disease spread through pig sales, demonstrating their importance for disease control. Familial fattening farms with high pig purchases were at greater risk of disease introduction and should be targeted for disease detection as part of a risk-based surveillance. In contrast, many other familial farms were isolated or weakly connected to the swine trade network limiting their relevance for surveillance activities. However, some of these farms used boar hiring for breeding, increasing the risk of disease spread. Most familial farms were slaughtering pigs at the farm or in small local slaughterhouses, making the surveillance at the slaughterhouse inefficient. In terms of spatial distribution of the trades, the results suggested that northern provinces were highly connected and showed some connection with central and southern provinces. These results are useful to develop risk-based surveillance protocols for disease detection in the swine familial sector and to make recommendations for disease control. © 2015 Blackwell Verlag GmbH.

The trading rectangle strategy within book models

NASA Astrophysics Data System (ADS)

Matassini, Lorenzo

2001-12-01

We introduce a model of trading where traders interact through the insertion of orders in the book. This matching mechanism is a collection of the activity of agents: They can trade at the market price or place a limit order. The latter is valid until cancelled by the trader; to this end we introduce a threshold in time after which the probability of the order to be removed is strongly increased. There is essentially no source of randomness and all the traders share a common strategy, what we call trading rectangle. Since there are no fundamentalist rules, it is not so important to identify the right moment to enter in the market. Much more effort is required to decide when to sell. The model is able to reproduce many of the complex phenomena manifested in real stock markets, including the positive correlation between bid/ask spreads and volatility.

Trading strategy based on dynamic mode decomposition: Tested in Chinese stock market

NASA Astrophysics Data System (ADS)

Cui, Ling-xiao; Long, Wen

2016-11-01

Dynamic mode decomposition (DMD) is an effective method to capture the intrinsic dynamical modes of complex system. In this work, we adopt DMD method to discover the evolutionary patterns in stock market and apply it to Chinese A-share stock market. We design two strategies based on DMD algorithm. The strategy which considers only timing problem can make reliable profits in a choppy market with no prominent trend while fails to beat the benchmark moving-average strategy in bull market. After considering the spatial information from spatial-temporal coherent structure of DMD modes, we improved the trading strategy remarkably. Then the DMD strategies profitability is quantitatively evaluated by performing SPA test to correct the data-snooping effect. The results further prove that DMD algorithm can model the market patterns well in sideways market.

Developing trading strategies based on fractal finance: An application of MF-DFA in the context of Islamic equities

NASA Astrophysics Data System (ADS)

Dewandaru, Ginanjar; Masih, Rumi; Bacha, Obiyathulla Ismath; Masih, A. Mansur. M.

2015-11-01

We provide a new contribution to trading strategies by using multi-fractal de-trended fluctuation analysis (MF-DFA), imported from econophysics, to complement various momentum strategies. The method provides a single measure that can capture both persistency and anti-persistency in stock prices, accounting for multifractality. This study uses a sample of Islamic stocks listed in the U.S. Dow Jones Islamic market for a sample period covering 16 years starting in 1996. The findings show that the MF-DFA strategy produces monthly excess returns of 6.12%, outperforming other various momentum strategies. Even though the risk of the MF-DFA strategy may be relatively higher, it can still produce a Sharpe ratio of 0.164, which is substantially higher than that of the other strategies. When we control for the MF-DFA factor with the other factors, its pure factor return is still able to yield a monthly excess return of 1.35%. Finally, we combine the momentum and MF-DFA strategies, with the proportions of 90/10, 80/20, and 70/30 and by doing so we demonstrate that the MF-DFA measure can boost the total monthly excess returns as well as Sharpe ratio. The value added is non-linear which implies that the additional returns are associated with lower incremental risk.

Energetic cost of communication.

PubMed

Stoddard, Philip K; Salazar, Vielka L

2011-01-15

Communication signals may be energetically expensive or inexpensive to produce, depending on the function of the signal and the competitive nature of the communication system. Males of sexually selected species may produce high-energy advertisement signals, both to enhance detectability and to signal their size and body condition. Accordingly, the proportion of the energy budget allocated to signal production ranges from almost nothing for many signals to somewhere in excess of 50% for acoustic signals in short-lived sexually selected species. Recent data from gymnotiform electric fish reveal mechanisms that regulate energy allocated to sexual advertisement signals through dynamical remodeling of the excitable membranes in the electric organ. Further, males of the short-lived sexually selected species, Brachyhypopomus gauderio, trade off among different metabolic compartments, allocating energy to signal production while reducing energy used in other metabolic functions. Female B. gauderio, by contrast, do not trade off energy between signaling and other functions. To fuel energetically expensive signal production, we expect a continuum of strategies to be adopted by animals of different life history strategies. Future studies should explore the relation between life history and energy allocation trade-offs.

Energetic cost of communication

PubMed Central

Stoddard, Philip K.; Salazar, Vielka L.

2011-01-01

Communication signals may be energetically expensive or inexpensive to produce, depending on the function of the signal and the competitive nature of the communication system. Males of sexually selected species may produce high-energy advertisement signals, both to enhance detectability and to signal their size and body condition. Accordingly, the proportion of the energy budget allocated to signal production ranges from almost nothing for many signals to somewhere in excess of 50% for acoustic signals in short-lived sexually selected species. Recent data from gymnotiform electric fish reveal mechanisms that regulate energy allocated to sexual advertisement signals through dynamical remodeling of the excitable membranes in the electric organ. Further, males of the short-lived sexually selected species, Brachyhypopomus gauderio, trade off among different metabolic compartments, allocating energy to signal production while reducing energy used in other metabolic functions. Female B. gauderio, by contrast, do not trade off energy between signaling and other functions. To fuel energetically expensive signal production, we expect a continuum of strategies to be adopted by animals of different life history strategies. Future studies should explore the relation between life history and energy allocation trade-offs. PMID:21177941

Uncovering Ecosystem Service Bundles through Social Preferences

PubMed Central

Martín-López, Berta; Iniesta-Arandia, Irene; García-Llorente, Marina; Palomo, Ignacio; Casado-Arzuaga, Izaskun; Amo, David García Del; Gómez-Baggethun, Erik; Oteros-Rozas, Elisa; Palacios-Agundez, Igone; Willaarts, Bárbara; González, José A.; Santos-Martín, Fernando; Onaindia, Miren; López-Santiago, Cesar; Montes, Carlos

2012-01-01

Ecosystem service assessments have increasingly been used to support environmental management policies, mainly based on biophysical and economic indicators. However, few studies have coped with the social-cultural dimension of ecosystem services, despite being considered a research priority. We examined how ecosystem service bundles and trade-offs emerge from diverging social preferences toward ecosystem services delivered by various types of ecosystems in Spain. We conducted 3,379 direct face-to-face questionnaires in eight different case study sites from 2007 to 2011. Overall, 90.5% of the sampled population recognized the ecosystem’s capacity to deliver services. Formal studies, environmental behavior, and gender variables influenced the probability of people recognizing the ecosystem’s capacity to provide services. The ecosystem services most frequently perceived by people were regulating services; of those, air purification held the greatest importance. However, statistical analysis showed that socio-cultural factors and the conservation management strategy of ecosystems (i.e., National Park, Natural Park, or a non-protected area) have an effect on social preferences toward ecosystem services. Ecosystem service trade-offs and bundles were identified by analyzing social preferences through multivariate analysis (redundancy analysis and hierarchical cluster analysis). We found a clear trade-off among provisioning services (and recreational hunting) versus regulating services and almost all cultural services. We identified three ecosystem service bundles associated with the conservation management strategy and the rural-urban gradient. We conclude that socio-cultural preferences toward ecosystem services can serve as a tool to identify relevant services for people, the factors underlying these social preferences, and emerging ecosystem service bundles and trade-offs. PMID:22720006

Uncovering ecosystem service bundles through social preferences.

PubMed

Martín-López, Berta; Iniesta-Arandia, Irene; García-Llorente, Marina; Palomo, Ignacio; Casado-Arzuaga, Izaskun; Amo, David García Del; Gómez-Baggethun, Erik; Oteros-Rozas, Elisa; Palacios-Agundez, Igone; Willaarts, Bárbara; González, José A; Santos-Martín, Fernando; Onaindia, Miren; López-Santiago, Cesar; Montes, Carlos

2012-01-01

Ecosystem service assessments have increasingly been used to support environmental management policies, mainly based on biophysical and economic indicators. However, few studies have coped with the social-cultural dimension of ecosystem services, despite being considered a research priority. We examined how ecosystem service bundles and trade-offs emerge from diverging social preferences toward ecosystem services delivered by various types of ecosystems in Spain. We conducted 3,379 direct face-to-face questionnaires in eight different case study sites from 2007 to 2011. Overall, 90.5% of the sampled population recognized the ecosystem's capacity to deliver services. Formal studies, environmental behavior, and gender variables influenced the probability of people recognizing the ecosystem's capacity to provide services. The ecosystem services most frequently perceived by people were regulating services; of those, air purification held the greatest importance. However, statistical analysis showed that socio-cultural factors and the conservation management strategy of ecosystems (i.e., National Park, Natural Park, or a non-protected area) have an effect on social preferences toward ecosystem services. Ecosystem service trade-offs and bundles were identified by analyzing social preferences through multivariate analysis (redundancy analysis and hierarchical cluster analysis). We found a clear trade-off among provisioning services (and recreational hunting) versus regulating services and almost all cultural services. We identified three ecosystem service bundles associated with the conservation management strategy and the rural-urban gradient. We conclude that socio-cultural preferences toward ecosystem services can serve as a tool to identify relevant services for people, the factors underlying these social preferences, and emerging ecosystem service bundles and trade-offs.

Multidimensional trade-offs in species responses to disturbance: implications for diversity in a subtropical forest.

PubMed

Uriarte, María; Clark, James S; Zimmerman, Jess K; Comita, Liza S; Forero-Montaña, Jimena; Thompson, Jill

2012-01-01

Species employ diverse strategies to cope with natural disturbance, but the importance of these strategies for maintaining tree species diversity in forests has been debated. Mechanisms that have the potential to promote tree species coexistence in the context of repeated disturbance include life history trade-offs in colonization and competitive ability or in species' ability to survive at low resource conditions and exploit the temporary resource-rich conditions often generated in the wake of disturbance (successional niche). Quantifying these trade-offs requires long-term forest monitoring and modeling. We developed a hierarchical Bayes model to investigate the strategies tree species employ to withstand and recover from hurricane disturbance and the life history trade-offs that may facilitate species coexistence in forests subject to repeated hurricane disturbance. Unlike previous approaches, our model accommodates temporal variation in process error and observations from multiple sources. We parameterized the model using growth and mortality data from four censuses of a 16-ha plot taken every five years (1990-2005), together with damage data collected after two hurricanes and annual seed production data (1992-2005). Species' susceptibilities to hurricane damage as reflected by changes in diameter growth and fecundity immediately following a storm were weak, highly variable, and unpredictable using traditional life history groupings. The lower crowding conditions (e.g., high light) generated in the wake of storms, however, led to greater gains in growth and fecundity for pioneer and secondary-forest species than for shade-tolerant species, in accordance with expectation of life history. We found moderate trade-offs between survival in high crowding conditions, a metric of competitive ability, and long-distance colonization. We also uncovered a strong trade-off between mean species fecundity in low crowding conditions, a metric of recovery potential, and competitive ability. Trade-offs in competitive and colonization ability, in addition to successional niche processes, are likely to contribute to species persistence in these hurricane-impacted forests. The strategies species employ to cope with hurricane damage depend on the degree to which species rely on sprouting, repair of adult damage, changes in demographic rates in response to enhanced resource availability after storms, or long-distance dispersal as recovery mechanisms.

The evolution of the competition-dispersal trade-off affects α- and β-diversity in a heterogeneous metacommunity.

PubMed

Laroche, Fabien; Jarne, Philippe; Perrot, Thomas; Massol, Francois

2016-04-27

Difference in dispersal ability is a key driver of species coexistence in metacommunities. However, the available frameworks for interpreting species diversity patterns in natura often overlook trade-offs and evolutionary constraints associated with dispersal. Here, we build a metacommunity model accounting for dispersal evolution and a competition-dispersal trade-off. Depending on the distribution of carrying capacities among communities, species dispersal values are distributed either around a single strategy (evolutionarily stable strategy, ESS), or around distinct strategies (evolutionary branching, EB). We show that limited dispersal generates spatial aggregation of dispersal traits in ESS and EB scenarios, and that the competition-dispersal trade-off strengthens the pattern in the EB scenario. Importantly, individuals in larger (respectively (resp.) smaller) communities tend to harbour lower (resp. higher) dispersal, especially under the EB scenario. We explore how dispersal evolution affects species diversity patterns by comparing those from our model to the predictions of a neutral metacommunity model. The most marked difference is detected under EB, with distinctive values of both α- and β-diversity (e.g. the dissimilarity in species composition between small and large communities was significantly larger than neutral predictions). We conclude that, from an empirical perspective, jointly assessing community carrying capacity with species dispersal strategies should improve our understanding of diversity patterns in metacommunities. © 2016 The Author(s).

Dependence structure of the commodity and stock markets, and relevant multi-spread strategy

NASA Astrophysics Data System (ADS)

Kim, Min Jae; Kim, Sehyun; Jo, Yong Hwan; Kim, Soo Yong

2011-10-01

Understanding the dependence structure between the commodity and stock markets is a crucial issue in constructing a portfolio. It can also help us to discover new opportunities to implement spread trading using multiple assets classified in the two different markets. This study analyzed the dependence structure of the commodity and stock markets using the random matrix theory technique and network analysis. Our results show that the stock and commodity markets must be handled as completely separated asset classes except for the oil and gold markets, so the performance enhancement of the mean-variance portfolio is significant as expected. In light of the fact that WTI 1 month futures and four oil-related stocks are strongly correlated, they were selected as basic ingredients to complement the multi-spread convergence trading strategy using a machine learning technique called the AdaBoost algorithm. The performance of this strategy for non-myopic investors, who can endure short-term loss, can be enhanced significantly on a risk measurement basis.

Considering WTO law in the design of climate change regimes beyond Kyoto

NASA Astrophysics Data System (ADS)

Gaines, Sanford E.

2009-11-01

This article describes the most important provisions of World Trade Organization (WTO) agreements that should be considered in designing laws and regulations under likely post-Kyoto climate change mitigation regimes. The Kyoto Protocol and the expected post-Kyoto international climate agreement depend on national measures to implement market-based mitigation measures. This market strategy promotes international exchanges of goods, investments, and services such as cross-border trading of credits for emissions reductions and transnational financing for projects that avoid emissions through the Clean Development Mechanism. Moreover, the United States and other countries, concerned over "leakage" of greenhouse gas (GHG) emissions through relocation of industry to other countries coupled with political worry over manufacturing competitiveness, have proposed national climate legislation containing border adjustments on imported goods or implicit subsidies for national producers, raising additional WTO considerations. The article assesses the likely effectiveness of such trade-related measures in achieving climate change mitigation goals and the potential trade policy infringements and trade distortions that they might bring about. Alternative strategies for achieving GHG mitigation goals in closer conformity with WTO law and policy will be suggested.

Decoupled dimensions of leaf economic and anti-herbivore defense strategies in a tropical canopy tree community.

PubMed

Chauvin, K McManus; Asner, G P; Martin, R E; Kress, W J; Wright, S J; Field, C B

2018-03-01

Trade-offs among plant functional traits indicate diversity in plant strategies of growth and survival. The leaf economics spectrum (LES) reflects a trade-off between short-term carbon gain and long-term leaf persistence. A related trade-off, between foliar growth and anti-herbivore defense, occurs among plants growing in contrasting resource regimes, but it is unclear whether this trade-off is maintained within plant communities, where resource gradients are minimized. The LES and the growth-defense trade-off involve related traits, but the extent to which these trade-off dimensions are correlated is poorly understood. We assessed the relationship between leaf economic and anti-herbivore defense traits among sunlit foliage of 345 canopy trees in 83 species on Barro Colorado Island, Panama. We quantified ten traits related to resource allocation and defense, and identified patterns of trait co-variation using multivariate ordination. We tested whether traits and ordination axes were correlated with patterns of phylogenetic relatedness, juvenile demographic trade-offs, or topo-edaphic variation. Two independent axes described ~ 60% of the variation among canopy trees. Axis 1 revealed a trade-off between leaf nutritional and structural investment, consistent with the LES. Physical defense traits were largely oriented along this axis. Axis 2 revealed a trade-off between investments in phenolic defenses versus other foliar defenses, which we term the leaf defense spectrum. Phylogenetic relationships and topo-edaphic variation largely did not explain trait co-variation. Our results suggest that some trade-offs among the growth and defense traits of outer-canopy trees may be captured by the LES, while others may occur along additional resource allocation dimensions.

Nest site selection by Kentish plover suggests a trade-off between nest-crypsis and predator detection strategies.

PubMed

Gómez-Serrano, Miguel Ángel; López-López, Pascual

2014-01-01

Predation is one of the main causes of adult mortality and breeding failure for ground-nesting birds. Micro-habitat structure around nests plays a critical role in minimizing predation risk. Plovers nest in sites with little vegetation cover to maximize the incubating adult visibility, but many studies suggest a trade-off between nest-crypsis and predator detection strategies. However, this trade-off has not been explored in detail because methods used so far do not allow estimating the visibility with regards to critical factors such as slope or plant permeability to vision. Here, we tested the hypothesis that Kentish plovers select exposed sites according to a predator detection strategy, and the hypothesis that more concealed nests survive longer according to a crypsis strategy. To this end, we obtained an accurate estimation of the incubating adult's field of vision through a custom built inverted periscope. Our results showed that plovers selected nest sites with higher visibility than control points randomly selected with regards to humans and dogs, although nests located in sites with higher vegetation cover survived longer. In addition, the flushing distance (i.e., the distance at which incubating adults leave the nest when they detect a potential predator) decreased with vegetation cover. Consequently, the advantages of concealing the nest were limited by the ability to detect predators, thus indirectly supporting the existence of the trade-off between crypsis and predator detection. Finally, human disturbance also constrained nest choice, forcing plovers to move to inland sites that were less suitable because of higher vegetation cover, and modulated flushing behavior, since plovers that were habituated to humans left their nests closer to potential predators. This constraint on the width of suitable breeding habitat is particularly relevant for the conservation of Kentish Plover in sand beaches, especially under the current context of coastal regression and increase of recreational activities.

Nest Site Selection by Kentish Plover Suggests a Trade-Off between Nest-Crypsis and Predator Detection Strategies

PubMed Central

Gómez-Serrano, Miguel Ángel; López-López, Pascual

2014-01-01

Predation is one of the main causes of adult mortality and breeding failure for ground-nesting birds. Micro-habitat structure around nests plays a critical role in minimizing predation risk. Plovers nest in sites with little vegetation cover to maximize the incubating adult visibility, but many studies suggest a trade-off between nest-crypsis and predator detection strategies. However, this trade-off has not been explored in detail because methods used so far do not allow estimating the visibility with regards to critical factors such as slope or plant permeability to vision. Here, we tested the hypothesis that Kentish plovers select exposed sites according to a predator detection strategy, and the hypothesis that more concealed nests survive longer according to a crypsis strategy. To this end, we obtained an accurate estimation of the incubating adult's field of vision through a custom built inverted periscope. Our results showed that plovers selected nest sites with higher visibility than control points randomly selected with regards to humans and dogs, although nests located in sites with higher vegetation cover survived longer. In addition, the flushing distance (i.e., the distance at which incubating adults leave the nest when they detect a potential predator) decreased with vegetation cover. Consequently, the advantages of concealing the nest were limited by the ability to detect predators, thus indirectly supporting the existence of the trade-off between crypsis and predator detection. Finally, human disturbance also constrained nest choice, forcing plovers to move to inland sites that were less suitable because of higher vegetation cover, and modulated flushing behavior, since plovers that were habituated to humans left their nests closer to potential predators. This constraint on the width of suitable breeding habitat is particularly relevant for the conservation of Kentish Plover in sand beaches, especially under the current context of coastal regression and increase of recreational activities. PMID:25208045

Optimal trading strategies—a time series approach

NASA Astrophysics Data System (ADS)

Bebbington, Peter A.; Kühn, Reimer

2016-05-01

Motivated by recent advances in the spectral theory of auto-covariance matrices, we are led to revisit a reformulation of Markowitz’ mean-variance portfolio optimization approach in the time domain. In its simplest incarnation it applies to a single traded asset and allows an optimal trading strategy to be found which—for a given return—is minimally exposed to market price fluctuations. The model is initially investigated for a range of synthetic price processes, taken to be either second order stationary, or to exhibit second order stationary increments. Attention is paid to consequences of estimating auto-covariance matrices from small finite samples, and auto-covariance matrix cleaning strategies to mitigate against these are investigated. Finally we apply our framework to real world data.

Tobacco control and trade policy: proactive strategies for integrating policy norms.

PubMed

Drope, Jeffrey; Lencucha, Raphael

2013-01-01

Palpable tension continues at the intersection of tobacco control and trade policy. Through consideration of four major tobacco control-related trade disputes, we suggest how to empower public health proponents in the face of entrenched economic policymaking norms. We argue that a more effective pro-tobacco control message should: (a) seek to be broadly consistent with core principles of the world trading system, (b) boldly assert countries' international commitments to the Framework Convention on Tobacco Control, (c) marshal deep scientific evidence, and (d) come from a broad range of actors, including from low- and middle-income countries as well as from other trade policy community members.

Defense Technology and Trade Initiative: Ashton Carter’s Strategy in India

DTIC Science & Technology

2016-03-01

Defense AT&L: March-April 2016 26 Defense Technology and Trade Initiative Ashton Carter’s Strategy in India Amit K. Maitra Maitra is a founding...officials to work on initiatives that were set in motion during President Obama’s January 2015 visit to India . During that visit, Obama and Indian Prime...engine technology. Modi, who has a broad vision of India as a global power, has a noticeably great affinity for the United States. Also, in the wake

Predicting vegetation type through physiological and environmental interactions with leaf traits: evergreen and deciduous forests in an earth system modeling framework.

PubMed

Weng, Ensheng; Farrior, Caroline E; Dybzinski, Ray; Pacala, Stephen W

2017-06-01

Earth system models are incorporating plant trait diversity into their land components to better predict vegetation dynamics in a changing climate. However, extant plant trait distributions will not allow extrapolations to novel community assemblages in future climates, which will require a mechanistic understanding of the trade-offs that determine trait diversity. In this study, we show how physiological trade-offs involving leaf mass per unit area (LMA), leaf lifespan, leaf nitrogen, and leaf respiration may explain the distribution patterns of evergreen and deciduous trees in the temperate and boreal zones based on (1) an evolutionary analysis of a simple mathematical model and (2) simulation experiments of an individual-based dynamic vegetation model (i.e., LM3-PPA). The evolutionary analysis shows that these leaf traits set up a trade-off between carbon- and nitrogen-use efficiency at the scale of individual trees and therefore determine competitively dominant leaf strategies. As soil nitrogen availability increases, the dominant leaf strategy switches from one that is high in nitrogen-use efficiency to one that is high in carbon-use efficiency or, equivalently, from high-LMA/long-lived leaves (i.e., evergreen) to low-LMA/short-lived leaves (i.e., deciduous). In a region of intermediate soil nitrogen availability, the dominant leaf strategy may be either deciduous or evergreen depending on the initial conditions of plant trait abundance (i.e., founder controlled) due to feedbacks of leaf traits on soil nitrogen mineralization through litter quality. Simulated successional patterns by LM3-PPA from the leaf physiological trade-offs are consistent with observed successional dynamics of evergreen and deciduous forests at three sites spanning the temperate to boreal zones. © 2016 John Wiley & Sons Ltd.

Recent evolution of China's virtual water trade: analysis of selected crops and considerations for policy

NASA Astrophysics Data System (ADS)

Shi, J.; Liu, J.; Pinter, L.

2014-04-01

China has dramatically increased its virtual water import over recent years. Many studies have focused on the quantity of traded virtual water, but very few go into analysing geographic distribution and the properties of China's virtual water trade network. This paper provides a calculation and analysis of the crop-related virtual water trade network of China based on 27 major primary crops between 1986 and 2009. The results show that China is a net importer of virtual water from water-abundant areas of North America and South America, and a net virtual water exporter to water-stressed areas of Asia, Africa, and Europe. Virtual water import is far larger than virtual water export, and in both import and export a small number of trade partners control the supply chain. Grain crops are the major contributors to virtual water trade, and among grain crops, soybeans, mostly imported from the US, Brazil and Argentina, are the most significant. In order to mitigate water scarcity and secure the food supply, virtual water should actively be incorporated into national water management strategies. And the sources of virtual water import need to be further diversified to reduce supply chain risks and increase resilience.

A water market simulator considering pair-wise trades between agents

NASA Astrophysics Data System (ADS)

Huskova, I.; Erfani, T.; Harou, J. J.

2012-04-01

In many basins in England no further water abstraction licences are available. Trading water between water rights holders has been recognized as a potentially effective and economically efficient strategy to mitigate increasing scarcity. A screening tool that could assess the potential for trade through realistic simulation of individual water rights holders would help assess the solution's potential contribution to local water management. We propose an optimisation-driven water market simulator that predicts pair-wise trade in a catchment and represents its interaction with natural hydrology and engineered infrastructure. A model is used to emulate licence-holders' willingness to engage in short-term trade transactions. In their simplest form agents are represented using an economic benefit function. The working hypothesis is that trading behaviour can be partially predicted based on differences in marginal values of water over space and time and estimates of transaction costs on pair-wise trades. We discuss the further possibility of embedding rules, norms and preferences of the different water user sectors to more realistically represent the behaviours, motives and constraints of individual licence holders. The potential benefits and limitations of such a social simulation (agent-based) approach is contrasted with our simulator where agents are driven by economic optimization. A case study based on the Dove River Basin (UK) demonstrates model inputs and outputs. The ability of the model to suggest impacts of water rights policy reforms on trading is discussed.

Effluent trading in river systems through stochastic decision-making process: a case study.

PubMed

Zolfagharipoor, Mohammad Amin; Ahmadi, Azadeh

2017-09-01

The objective of this paper is to provide an efficient framework for effluent trading in river systems. The proposed framework consists of two pessimistic and optimistic decision-making models to increase the executability of river water quality trading programs. The models used for this purpose are (1) stochastic fallback bargaining (SFB) to reach an agreement among wastewater dischargers and (2) stochastic multi-criteria decision-making (SMCDM) to determine the optimal treatment strategy. The Monte-Carlo simulation method is used to incorporate the uncertainty into analysis. This uncertainty arises from stochastic nature and the errors in the calculation of wastewater treatment costs. The results of river water quality simulation model are used as the inputs of models. The proposed models are used in a case study on the Zarjoub River in northern Iran to determine the best solution for the pollution load allocation. The best treatment alternatives selected by each model are imported, as the initial pollution discharge permits, into an optimization model developed for trading of pollution discharge permits among pollutant sources. The results show that the SFB-based water pollution trading approach reduces the costs by US$ 14,834 while providing a relative consensus among pollutant sources. Meanwhile, the SMCDM-based water pollution trading approach reduces the costs by US$ 218,852, but it is less acceptable by pollutant sources. Therefore, it appears that giving due attention to stability, or in other words acceptability of pollution trading programs for all pollutant sources, is an essential element of their success.

Constraints on gene patent protection fuel secrecy concerns: a qualitative study

PubMed Central

Guerrini, Christi J; McGuire, Amy L; Majumder, Mary A; Bollinger, Juli M; Rowan, Paul J

2017-01-01

Abstract Concern is mounting that innovators are responding to recent changes in patent eligibility by increasingly choosing to protect their discoveries as trade secrets. Due to the clandestine nature of trade secrets, it is impossible to quantify the extent to which innovators actually elect to protect their inventions as trade secrets rather than patents. Nevertheless, interest in each strategy may be gauged through qualitative means. We conducted semi-structured interviews of legal and scientific experts (n = 30) to understand the effect of recent patent eligibility changes on interest in patenting and trade secrecy of genetic innovations. Interview data indicate that secrecy may have increased in strategic appeal relative to patent protection in some areas of genetic innovation, although the actual election of secrecy strategies is often limited as a practical matter. The data also suggest that the burden of navigating the new intellectual property landscape may be falling disproportionately on those who translate gene-based discoveries into clinical applications. Some interviewees expressed concern about the normative implications of secrecy on advancements in and access to genetic medicine. Our findings are potentially relevant to policy proposals intended to restore some of the legal protection that was lost as a result of recent changes to patent eligibility, including amending the federal patent statute and expanding regulatory exclusivities for some genetic technologies. PMID:29868184

Strategies for obtaining obsidian in pre-European contact era New Zealand.

PubMed

McCoy, Mark D; Carpenter, Jonathan

2014-01-01

Archaeological evidence of people's choices regarding how they supply themselves with obsidian through direct access and different types of exchanges gives us insight in to mobility, social networks, and property rights in the distant past. Here we use collections of obsidian artefacts that date to a period of endemic warfare among Maori during New Zealand's Late Period (1500-1769 A.D.) to determine what strategies people engaged in to obtain obsidian, namely (1) collecting raw material directly from a natural source, (2) informal trade and exchange, and (3) formal trade and exchange. These deposits represent a good cross-section of Late Period archaeology, including primary working of raw material at a natural source (Helena Bay), undefended sites where people discarded rubbish and worked obsidian (Bream Head), and a heavily fortified site (Mt. Wellington). We find that most of the obsidian described here was likely obtained directly from natural sources, especially those located on off-shore islands within about 60-70 km of sites. A smaller amount comes from blocks of material transported from an off-shore island a greater distance away, called Mayor Island, in a formal trade and exchange network. This study demonstrates the value of conducting tandem lithic technology and geochemical sourcing studies to understand how people create and maintain social networks during periods of warfare.

United States Strategy Toward China After a Peaceful Taiwan Strait Resolution

DTIC Science & Technology

2005-12-01

19 B. THE INTERTWINING OF ECONOMIES: THE TRADE DEFICIT, THE...D. TRADE RELATIONSHIPS AND CHINESE LEADERSHIP..................31 E. SUMMARY...Deng Xiaoping, these changes transformed the backwards Chinese economy and provided yet another sign that the Chinese giant was awakening. Following

Cancer: A disease at the crossroads of trade-offs.

PubMed

Jacqueline, Camille; Biro, Peter A; Beckmann, Christa; Moller, Anders Pape; Renaud, François; Sorci, Gabriele; Tasiemski, Aurélie; Ujvari, Beata; Thomas, Frédéric

2017-03-01

Central to evolutionary theory is the idea that living organisms face phenotypic and/or genetic trade-offs when allocating resources to competing life-history demands, such as growth, survival, and reproduction. These trade-offs are increasingly considered to be crucial to further our understanding of cancer. First, evidences suggest that neoplastic cells, as any living entities subject to natural selection, are governed by trade-offs such as between survival and proliferation. Second, selection might also have shaped trade-offs at the organismal level, especially regarding protective mechanisms against cancer. Cancer can also emerge as a consequence of additional trade-offs in organisms (e.g., eco-immunological trade-offs). Here, we review the wide range of trade-offs that occur at different scales and their relevance for understanding cancer dynamics. We also discuss how acknowledging these phenomena, in light of human evolutionary history, may suggest new guidelines for preventive and therapeutic strategies.

Optimal Defense Strategies in an Idealized Microbial Food Web under Trade-Off between Competition and Defense

PubMed Central

Våge, Selina; Storesund, Julia E.; Giske, Jarl; Thingstad, T. Frede

2014-01-01

Trophic mechanisms that can generate biodiversity in food webs include bottom-up (growth rate regulating) and top-down (biomass regulating) factors. The top-down control has traditionally been analyzed using the concepts of “Keystone Predation” (KP) and “Killing-the-Winner” (KtW), predominately occuring in discussions of macro- and micro-biological ecology, respectively. Here we combine the classical diamond-shaped food web structure frequently discussed in KP analyses and the KtW concept by introducing a defense strategist capable of partial defense. A formalized description of a trade-off between the defense-strategist's competitive and defensive ability is included. The analysis reveals a complex topology of the steady state solution with strong relationships between food web structure and the combination of trade-off, defense strategy and the system's nutrient content. Among the results is a difference in defense strategies corresponding to maximum biomass, production, or net growth rate of invading individuals. The analysis thus summons awareness that biomass or production, parameters typically measured in field studies to infer success of particular biota, are not directly acted upon by natural selection. Under coexistence with a competition specialist, a balance of competitive and defensive ability of the defense strategist was found to be evolutionarily stable, whereas stronger defense was optimal under increased nutrient levels in the absence of the pure competition specialist. The findings of success of different defense strategies are discussed with respect to SAR11, a highly successful bacterial clade in the pelagic ocean. PMID:24999739

Trade in water and commodities as adaptations to global change

NASA Astrophysics Data System (ADS)

Lammers, R. B.; Hertel, T. W.; Prousevitch, A.; Baldos, U. L. C.; Frolking, S. E.; Liu, J.; Grogan, D. S.

2015-12-01

The human capacity for altering the water cycle has been well documented and given the expected change due to population, income growth, biofuels, climate, and associated land use change, there remains great uncertainty in both the degree of increased pressure on land and water resources and in our ability to adapt to these changes. Alleviating regional shortages in water supply can be carried out in a spatial hierarchy through i) direct trade of water between all regions, ii) development of infrastructure to improve water availability within regions (e.g. impounding rivers), iii) via inter-basin hydrological transfer between neighboring regions and, iv) via virtual water trade. These adaptation strategies can be managed via market trade in water and commodities to identify those strategies most likely to be adopted. This work combines the physically-based University of New Hampshire Water Balance Model (WBM) with the macro-scale Purdue University Simplified International Model of agricultural Prices Land use and the Environment (SIMPLE) to explore the interaction of supply and demand for fresh water globally. In this work we use a newly developed grid cell-based version of SIMPLE to achieve a more direct connection between the two modeling paradigms of physically-based models with optimization-driven approaches characteristic of economic models. We explore questions related to the global and regional impact of water scarcity and water surplus on the ability of regions to adapt to future change. Allowing for a variety of adaptation strategies such as direct trade of water and expanding the built water infrastructure, as well as indirect trade in commodities, will reduce overall global water stress and, in some regions, significantly reduce their vulnerability to these future changes.

Communist coalmining union activists and postwar reconstruction, 1945-52: Germany, Poland, and Britain

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

Fishman, N.; Prazmowska, A.J.; Heith, H.

2006-01-15

The demand for coal in war-torn Europe after VE Day gave coalmining trade unions unprecedented bargaining leverage. Miners' incomes had been depressed throughout the interwar period, and they were now anxious to recover their past high wages and improve their conditions. In several key European countries, Communists were prominent among the leadership of mining trade unions. Communist miners' leaders Willi Agatz, Edward Gierek and Arthur Horner each faced unprecedented opportunities and challenges at the onset of the Cold War in 1948, as they sought to fuse their parallel identities as committed and influential Communists and as conscientious trade union negotiatorsmore » in these newly advantageous circumstances. Each of these three 'revolutionary' trade unionists pursued strategies that revived the position of miners, without undermining the potential for economic recovery in their respective countries - for which an uninterrupted supply of coal remained critical. A comparative study of the personal and political experiences of the three Communist miners' leaders enhances our understanding of the evolution of Communist trade unionism in the early postwar period.« less

Performance of technical trading rules: evidence from Southeast Asian stock markets.

PubMed

Tharavanij, Piyapas; Siraprapasiri, Vasan; Rajchamaha, Kittichai

2015-01-01

This paper examines the profitability of technical trading rules in the five Southeast Asian stock markets. The data cover a period of 14 years from January 2000 to December 2013. The instruments investigated are five Southeast Asian stock market indices: SET index (Thailand), FTSE Bursa Malaysia KLC index (Malaysia), FTSE Straits Times index (Singapore), JSX Composite index (Indonesia), and PSE composite index (the Philippines). Trading strategies investigated include Relative Strength Index, Stochastic oscillator, Moving Average Convergence-Divergence, Directional Movement Indicator and On Balance Volume. Performances are compared to a simple Buy-and-Hold. Statistical tests are also performed. Our empirical results show a strong performance of technical trading rules in an emerging stock market of Thailand but not in a more mature stock market of Singapore. The technical trading rules also generate statistical significant returns in the Malaysian, Indonesian and the Philippine markets. However, after taking transaction costs into account, most technical trading rules do not generate net returns. This fact suggests different levels of market efficiency among Southeast Asian stock markets. This paper finds three new insights. Firstly, technical indicators does not help much in terms of market timing. Basically, traders cannot expect to buy at a relative low price and sell at a relative high price by just using technical trading rules. Secondly, technical trading rules can be beneficial to individual investors as they help them to counter the behavioral bias called disposition effects which is the tendency to sell winning stocks too soon and holding on to losing stocks too long. Thirdly, even profitable strategies could not reliably predict subsequent market directions. They make money from having a higher average profit from profitable trades than an average loss from unprofitable ones.

Interregional sharing of energy conservation targets in China: Efficiency and equity

NASA Astrophysics Data System (ADS)

Wei, Dan

Energy conservation is a long-term strategic policy in China to support its economic and social development. This policy strategy is important for saving resources, protecting the environment, and ensuring the secure supply of energy to all economic activities. However, energy conservation often involves large amounts of investment and may also have dampening impacts on some local and regional economies. Moreover, energy conservation and efficiency improvement have many features of a public good. Therefore, government policy and intervention play a strong role to foster regional efforts and cooperative interregional actions on this issue. This dissertation introduces and analyzes a promising policy instrument---an interregional energy conservation-quota trading system---to help China fulfill its national energy conservation objective in an efficient and equitable way. To analyze the workings of the energy conservation-quota trading system, trading entities are first determined. In this study, statistical analyses (principal component analysis and cluster analysis) are applied to identify regional aggregations of provinces of China to act as the trading units. The marginal energy conservation cost curves of these regions are developed using engineering-economic methods and regression analysis. Simulations of interregional conservation-quota trading are undertaken after China's conservation goals in 2010 are allocated among regions according to several equity criteria. Various equity criteria are applied and analyzed in this study because of the philosophical differences in the appropriate definition of the concept. The trading simulations yield several important findings. First, the introduction of an interregional quota trading system can minimize both regional net compliance costs and national total conservation costs, irrespective of how the conservation tasks are initially allocated among regions according to different equity rules. Second, regional welfare implications differ across the applications of various equity criteria. However, for the energy production-based sovereignty and egalitarian equity criteria, the poorest region (in terms of per capita gross regional product) can enjoy net profits from trading, while the clustered region of wealthy coastal provinces shoulders the highest cost. This indicates that a conservation-quota trading system applying these two equity criteria is consistent with the national strategy in China to reduce regional income disparities and to develop the interior and western less-developed regions of the country. Third, compared with trading among conventional regions, trading among statistically clustered regions can more sharply apply the equity criteria to burden sharing and utilize larger differences in marginal conservation costs between regions to achieve a lower total net cost for the country as a whole. In sum, this research develops a useful methodology and identifies an operational way to attain energy conservation targets in China. It offers insights for similar interregional burden-sharing or benefit-sharing policies for China in the future, such as greenhouse gas emission trading, which is closely related to the energy conservation issue.

Evaluation of Contrail Reduction Strategies Based on Environmental and Operational Costs

NASA Technical Reports Server (NTRS)

Chen, Neil Y.; Sridhar, Banavar; Ng, Hok K.; Li, Jinhua

2013-01-01

This paper evaluates a set of contrail reduction strategies based on environmental and operational costs. A linear climate model was first used to convert climate effects of carbon dioxide emissions and aircraft contrails to changes in Absolute Global Temperature Potential, a metric that measures the mean surface temperature change due to aircraft emissions and persistent contrail formations. The concept of social cost of carbon and the carbon auction price from recent California's cap-and-trade system were then used to relate the carbon dioxide emissions and contrail formations to an environmental cost index. The strategy for contrail reduction is based on minimizing contrail formations by altering the aircraft's cruising altitude. The strategy uses a user-defined factor to trade off between contrail reduction and additional fuel burn and carbon dioxide emissions. A higher value of tradeoff factor results in more contrail reduction but also more fuel burn and carbon emissions. The strategy is considered favorable when the net environmental cost benefit exceeds the operational cost. The results show how the net environmental benefit varies with different decision-making time-horizon and different carbon cost. The cost models provide a guidance to select the trade-off factor that will result in the most net environmental benefit.

Assessment of Trading Partners for China's Rare Earth Exports Using a Decision Analytic Approach

PubMed Central

He, Chunyan; Lei, Yalin; Ge, Jianping

2014-01-01

Chinese rare earth export policies currently result in accelerating its depletion. Thus adopting an optimal export trade selection strategy is crucial to determining and ultimately identifying the ideal trading partners. This paper introduces a multi-attribute decision-making methodology which is then used to select the optimal trading partner. In the method, an evaluation criteria system is established to assess the seven top trading partners based on three dimensions: political relationships, economic benefits and industrial security. Specifically, a simple additive weighing model derived from an additive utility function is utilized to calculate, rank and select alternatives. Results show that Japan would be the optimal trading partner for Chinese rare earths. The criteria evaluation method of trading partners for China's rare earth exports provides the Chinese government with a tool to enhance rare earth industrial policies. PMID:25051534

Assessment of trading partners for China's rare earth exports using a decision analytic approach.

PubMed

He, Chunyan; Lei, Yalin; Ge, Jianping

2014-01-01

Chinese rare earth export policies currently result in accelerating its depletion. Thus adopting an optimal export trade selection strategy is crucial to determining and ultimately identifying the ideal trading partners. This paper introduces a multi-attribute decision-making methodology which is then used to select the optimal trading partner. In the method, an evaluation criteria system is established to assess the seven top trading partners based on three dimensions: political relationships, economic benefits and industrial security. Specifically, a simple additive weighing model derived from an additive utility function is utilized to calculate, rank and select alternatives. Results show that Japan would be the optimal trading partner for Chinese rare earths. The criteria evaluation method of trading partners for China's rare earth exports provides the Chinese government with a tool to enhance rare earth industrial policies.

Fluctuation-driven price dynamics and investment strategies

PubMed Central

Li, Yan; Zheng, Bo; Chen, Ting-Ting; Jiang, Xiong-Fei

2017-01-01

Investigation of the driven mechanism of the price dynamics in complex financial systems is important and challenging. In this paper, we propose an investment strategy to study how dynamic fluctuations drive the price movements. The strategy is successfully applied to different stock markets in the world, and the result indicates that the driving effect of the dynamic fluctuations is rather robust. We investigate how the strategy performance is influenced by the market states and optimize the strategy performance by introducing two parameters. The strategy is also compared with several typical technical trading rules. Our findings not only provide an investment strategy which extends investors’ profits, but also offer a useful method to look into the dynamic properties of complex financial systems. PMID:29240783

Fluctuation-driven price dynamics and investment strategies.

PubMed

Li, Yan; Zheng, Bo; Chen, Ting-Ting; Jiang, Xiong-Fei

2017-01-01

Investigation of the driven mechanism of the price dynamics in complex financial systems is important and challenging. In this paper, we propose an investment strategy to study how dynamic fluctuations drive the price movements. The strategy is successfully applied to different stock markets in the world, and the result indicates that the driving effect of the dynamic fluctuations is rather robust. We investigate how the strategy performance is influenced by the market states and optimize the strategy performance by introducing two parameters. The strategy is also compared with several typical technical trading rules. Our findings not only provide an investment strategy which extends investors' profits, but also offer a useful method to look into the dynamic properties of complex financial systems.

When Does Model-Based Control Pay Off?

PubMed Central

2016-01-01

Many accounts of decision making and reinforcement learning posit the existence of two distinct systems that control choice: a fast, automatic system and a slow, deliberative system. Recent research formalizes this distinction by mapping these systems to “model-free” and “model-based” strategies in reinforcement learning. Model-free strategies are computationally cheap, but sometimes inaccurate, because action values can be accessed by inspecting a look-up table constructed through trial-and-error. In contrast, model-based strategies compute action values through planning in a causal model of the environment, which is more accurate but also more cognitively demanding. It is assumed that this trade-off between accuracy and computational demand plays an important role in the arbitration between the two strategies, but we show that the hallmark task for dissociating model-free and model-based strategies, as well as several related variants, do not embody such a trade-off. We describe five factors that reduce the effectiveness of the model-based strategy on these tasks by reducing its accuracy in estimating reward outcomes and decreasing the importance of its choices. Based on these observations, we describe a version of the task that formally and empirically obtains an accuracy-demand trade-off between model-free and model-based strategies. Moreover, we show that human participants spontaneously increase their reliance on model-based control on this task, compared to the original paradigm. Our novel task and our computational analyses may prove important in subsequent empirical investigations of how humans balance accuracy and demand. PMID:27564094

When Does Model-Based Control Pay Off?

PubMed

Kool, Wouter; Cushman, Fiery A; Gershman, Samuel J

2016-08-01

Many accounts of decision making and reinforcement learning posit the existence of two distinct systems that control choice: a fast, automatic system and a slow, deliberative system. Recent research formalizes this distinction by mapping these systems to "model-free" and "model-based" strategies in reinforcement learning. Model-free strategies are computationally cheap, but sometimes inaccurate, because action values can be accessed by inspecting a look-up table constructed through trial-and-error. In contrast, model-based strategies compute action values through planning in a causal model of the environment, which is more accurate but also more cognitively demanding. It is assumed that this trade-off between accuracy and computational demand plays an important role in the arbitration between the two strategies, but we show that the hallmark task for dissociating model-free and model-based strategies, as well as several related variants, do not embody such a trade-off. We describe five factors that reduce the effectiveness of the model-based strategy on these tasks by reducing its accuracy in estimating reward outcomes and decreasing the importance of its choices. Based on these observations, we describe a version of the task that formally and empirically obtains an accuracy-demand trade-off between model-free and model-based strategies. Moreover, we show that human participants spontaneously increase their reliance on model-based control on this task, compared to the original paradigm. Our novel task and our computational analyses may prove important in subsequent empirical investigations of how humans balance accuracy and demand.

Alternative approaches to cargo policy : a supplement to an assessment of maritime trade and technology

DOT National Transportation Integrated Search

1985-08-01

When the Office of Technology Assessment (OTA) published An Assessment of Maritime Trade and Technology in October 1983, one of its principal findings was that because national interests were not defined and strategies for international negotiation h...

Influence of individual rationality on continuous double auction markets with networked traders

NASA Astrophysics Data System (ADS)

Zhang, Junhuan

2018-04-01

This paper investigates the influence of individual rationality of buyers and sellers on continuous double auction market outcomes in terms of the proportion of boundedly-rational buyers and sellers. The individual rationality is discussed in a social network artificial stock market model by embedding network formation and information set. Traders automatically select the most profitable trading strategy based on individual and social learning of the profits and trading strategies of themselves and their neighbors, and submit orders to markets. The results show that (i) a higher proportion of boundedly-rational sellers induces a higher market price, higher sellers' profits and a higher market efficiency; (ii) a higher proportion of boundedly-rational sellers induces a lower number of trades and lower buyers' profits; (iii) a higher proportion of boundedly-rational buyers induces a lower market price, a lower number of trades, and lower sellers' profits; (iv) a higher proportion of boundedly-rational buyers induces higher buyers' profits and a higher market efficiency.

An Integrated Environmental Assessment of Green and Gray Infrastructure Strategies for Robust Decision Making.

PubMed

Casal-Campos, Arturo; Fu, Guangtao; Butler, David; Moore, Andrew

2015-07-21

The robustness of a range of watershed-scale "green" and "gray" drainage strategies in the future is explored through comprehensive modeling of a fully integrated urban wastewater system case. Four socio-economic future scenarios, defined by parameters affecting the environmental performance of the system, are proposed to account for the uncertain variability of conditions in the year 2050. A regret-based approach is applied to assess the relative performance of strategies in multiple impact categories (environmental, economic, and social) as well as to evaluate their robustness across future scenarios. The concept of regret proves useful in identifying performance trade-offs and recognizing states of the world most critical to decisions. The study highlights the robustness of green strategies (particularly rain gardens, resulting in half the regret of most options) over end-of-pipe gray alternatives (surface water separation or sewer and storage rehabilitation), which may be costly (on average, 25% of the total regret of these options) and tend to focus on sewer flooding and CSO alleviation while compromising on downstream system performance (this accounts for around 50% of their total regret). Trade-offs and scenario regrets observed in the analysis suggest that the combination of green and gray strategies may still offer further potential for robustness.

Grayscale/resolution trade-off for text: Model predictions and psychophysical results for letter confusion and letter discrimination

NASA Technical Reports Server (NTRS)

Gille, Jennifer; Martin, Russel; Lubin, Jeffrey; Larimer, James

1995-01-01

In a series of papers presented in 1994, we examined the grayscale/resolution trade-off for natural images displayed on devices with discrete pixellation, such as AMLCD's. In the present paper we extend this study by examining the grayscale/resolution trade-off for text images on discrete-pixel displays. Halftoning in printing is an example of the grayscale/resolution trade-off. In printing, spatial resolution is sacrificed to produce grayscale. Another example of this trade-off is the inherent low-pass spatial filter of a CRT, caused by the point-spread function of the electron beam in the phosphor layer. On a CRT, sharp image edges are blurred by this inherent low-pass filtering, and the block noise created by spatial quantization is greatly reduced. A third example of this trade-off is text anti-aliasing, where grayscale is used to improve letter shape, size and location when rendered at a low spatial resolution. There are additional implications for display system design from the grayscale/resolution trade-off. For example, reduced grayscale can reduce system costs by requiring less complexity in the framestore, allowing the use of lower cost drivers, potentially increasing data transfer rates in the image subsystem, and simplifying the manufacturing processes that are used to construct the active matrix for AMLCD (active-matrix liquid-crystal display) or AMTFEL (active-matrix thin-film electroluminescent) devices. Therefore, the study of these trade-offs is important for display designers and manufacturing and systems engineers who wish to create the highest performance, lowest cost device possible. Our strategy for investigating this trade-off is to generate a set of simple test images, manipulate grayscale and resolution, predict discrimination performance using the ViDEOS(Sarnoff) Human Vision Model, conduct an empirical study of discrimination using psychophysical procedures, and verify the computational results using the psychophysical results.

Economic Sanctions Targeting Yugoslavia - An Effective National Security Strategy Component

DTIC Science & Technology

2003-01-22

withdrawal, of customary trade and financial relations with a target country in an effort to change that country’s policies.2 Policies are defined...primarily by political or military behavior. This excludes sanctions used to open up access to markets or compliance with trade agreements.3 These are...survived the test of time. Even a young United States implemented export sanctions in 1807. Napoleon blockaded trade between the continental Europe and

An Investigation of the Relationship between In-Class and Out-of-Class Efforts on Student Learning: Empirical Evidence and Strategy Suggestion

ERIC Educational Resources Information Center

Lin, Tin-Chun

2016-01-01

In this paper we explore and discuss an important research question in higher education--is there a trade-off relationship between in-class and out-of-class efforts for students? We used an empirical model to test the trade-off hypothesis between these two efforts. We identified a trade-off between in-class and out-of-class efforts, especially for…

Strategic research on the sustainable development cost of manufacturing industry under the background of carbon allowance and trade policy

NASA Astrophysics Data System (ADS)

Ma, Zhongmin; Cheng, Mengting; Wang, Mei

2017-08-01

The important subjects of energy consumption and carbon emission are manufacturing enterprises, with the deepening of international cooperation, and the implementation of carbon limit and trade policy, costs of manufacturing industry will rise sharply. How can the manufacturing industry survive in this reform, and it has to be a problem that the managers of the manufacturing industry need to solve. This paper analyses sustainable development cost connotation and value basis on the basis of sustainable development concept, discusses the influence of carbon allowance and trade policy for cost strategy of manufacturing industry, thinks that manufacturing industry should highlight social responsibility and realize maximization of social value, implement cost strategy the sustainable development, and pointed out the implementation way.

Like Hercules and the Hydra: Trade-offs and strategies in ecological model-building and experimental design.

PubMed

Inkpen, S Andrew

2016-06-01

Experimental ecologists often invoke trade-offs to describe the constraints they encounter when choosing between alternative experimental designs, such as between laboratory, field, and natural experiments. In making these claims, they tend to rely on Richard Levins' analysis of trade-offs in theoretical model-building. But does Levins' framework apply to experiments? In this paper, I focus this question on one desideratum widely invoked in the modelling literature: generality. Using the case of generality, I assess whether Levins-style treatments of modelling provide workable resources for assessing trade-offs in experimental design. I argue that, of four strategies modellers employ to increase generality, only one may be unproblematically applied to experimental design. Furthermore, modelling desiderata do not have obvious correlates in experimental design, and when we define these desiderata in a way that seem consistent with ecologists' usage, the trade-off framework falls apart. I conclude that a Levins-inspired framework for modelling does not provide the content for a similar approach to experimental practice; this does not, however, mean that it cannot provide the form. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Multilateral Negotiation Model for Cloud Service Market

NASA Astrophysics Data System (ADS)

Yoo, Dongjin; Sim, Kwang Mong

Trading cloud services between consumers and providers is a complicated issue of cloud computing. Since a consumer can negotiate with multiple providers to acquire the same service and each provider can receive many requests from multiple consumers, to facilitate the trading of cloud services among multiple consumers and providers, a multilateral negotiation model for cloud market is necessary. The contribution of this work is the proposal of a business model supporting a multilateral price negotiation for trading cloud services. The design of proposed systems for cloud service market includes considering a many-to-many negotiation protocol, and price determining factor from service level feature. Two negotiation strategies are implemented: 1) MDA (Market Driven Agent); and 2) adaptive concession making responding to changes of bargaining position are proposed for cloud service market. Empirical results shows that MDA achieved better performance in some cases that the adaptive concession making strategy, it is noted that unlike the MDA, the adaptive concession making strategy does not assume that an agent has information of the number of competitors (e.g., a consumer agent adopting the adaptive concession making strategy need not know the number of consumer agents competing for the same service).

Transformative Change Initiative

ERIC Educational Resources Information Center

Bragg, D. D.; Kirby, C.; Witt, M. A.; Richie, D.; Mix, S.; Feldbaum, M.; Liu, S.; Mason, M.

2014-01-01

The Transformative Change Initiative (TCI) is dedicated to assisting community colleges to scale up innovation in the form of guided pathways, programs of study, and evidence-based strategies to improve student outcomes and program, organization, and system performance. The impetus for TCI is the Trade Adjustment Assistance Community College and…

Exporting an Inherently Harmful Product: The Marketing of Virginia Slims Cigarettes in the United States, Japan, and Korea.

PubMed

Dewhirst, Timothy; Lee, Wonkyong B; Fong, Geoffrey T; Ling, Pamela M

2016-11-01

Ethical issues surrounding the marketing and trade of controversial products such as tobacco require a better understanding. Virginia Slims, an exclusively women's cigarette brand first launched in 1968 in the USA, was introduced during the mid 1980s to major Asian markets, such as Japan and Korea, dominated by male smokers. By reviewing internal corporate documents, made public from litigation, we examine the marketing strategies used by Philip Morris as they entered new markets such as Japan and Korea and consider the extent that the company attempted to appeal to women in markets where comparatively few women were smokers. The case study of Virginia Slims reveals that the classification of "vulnerable" consumers is variable depending on culture, tobacco firms display responsive efforts and strategies when operating within a "mature" market, and cultural values played a role in informing Philip Morris' strategic decision to embrace an adaptive marketing approach, particularly when entering the Korean market. Finally, moral questions are raised with tobacco being identified as a priority product for export and international trade agreements being used by corporations, governments, or trade partners in efforts to undermine domestic public health policies.

Exporting an Inherently Harmful Product: The Marketing of Virginia Slims Cigarettes in the United States, Japan, and Korea

PubMed Central

Lee, Wonkyong B.; Fong, Geoffrey T.; Ling, Pamela M.

2015-01-01

Ethical issues surrounding the marketing and trade of controversial products such as tobacco require a better understanding. Virginia Slims, an exclusively women’s cigarette brand first launched in 1968 in the USA, was introduced during the mid 1980s to major Asian markets, such as Japan and Korea, dominated by male smokers. By reviewing internal corporate documents, made public from litigation, we examine the marketing strategies used by Philip Morris as they entered new markets such as Japan and Korea and consider the extent that the company attempted to appeal to women in markets where comparatively few women were smokers. The case study of Virginia Slims reveals that the classification of “vulnerable” consumers is variable depending on culture, tobacco firms display responsive efforts and strategies when operating within a “mature” market, and cultural values played a role in informing Philip Morris’ strategic decision to embrace an adaptive marketing approach, particularly when entering the Korean market. Finally, moral questions are raised with tobacco being identified as a priority product for export and international trade agreements being used by corporations, governments, or trade partners in efforts to undermine domestic public health policies. PMID:28025588

Impact of information cost and switching of trading strategies in an artificial stock market

NASA Astrophysics Data System (ADS)

Liu, Yi-Fang; Zhang, Wei; Xu, Chao; Vitting Andersen, Jørgen; Xu, Hai-Chuan

2014-08-01

This paper studies the switching of trading strategies and its effect on the market volatility in a continuous double auction market. We describe the behavior when some uninformed agents, who we call switchers, decide whether or not to pay for information before they trade. By paying for the information they behave as informed traders. First we verify that our model is able to reproduce some of the stylized facts in real financial markets. Next we consider the relationship between switching and the market volatility under different structures of investors. We find that there exists a positive relationship between the market volatility and the percentage of switchers. We therefore conclude that the switchers are a destabilizing factor in the market. However, for a given fixed percentage of switchers, the proportion of switchers that decide to buy information at a given moment of time is negatively related to the current market volatility. In other words, if more agents pay for information to know the fundamental value at some time, the market volatility will be lower. This is because the market price is closer to the fundamental value due to information diffusion between switchers.

Using trading strategies to detect phase transitions in financial markets.

PubMed

Forró, Z; Woodard, R; Sornette, D

2015-04-01

We show that the log-periodic power law singularity model (LPPLS), a mathematical embodiment of positive feedbacks between agents and of their hierarchical dynamical organization, has a significant predictive power in financial markets. We find that LPPLS-based strategies significantly outperform the randomized ones and that they are robust with respect to a large selection of assets and time periods. The dynamics of prices thus markedly deviate from randomness in certain pockets of predictability that can be associated with bubble market regimes. Our hybrid approach, marrying finance with the trading strategies, and critical phenomena with LPPLS, demonstrates that targeting information related to phase transitions enables the forecast of financial bubbles and crashes punctuating the dynamics of prices.

Using trading strategies to detect phase transitions in financial markets

NASA Astrophysics Data System (ADS)

Forró, Z.; Woodard, R.; Sornette, D.

2015-04-01

We show that the log-periodic power law singularity model (LPPLS), a mathematical embodiment of positive feedbacks between agents and of their hierarchical dynamical organization, has a significant predictive power in financial markets. We find that LPPLS-based strategies significantly outperform the randomized ones and that they are robust with respect to a large selection of assets and time periods. The dynamics of prices thus markedly deviate from randomness in certain pockets of predictability that can be associated with bubble market regimes. Our hybrid approach, marrying finance with the trading strategies, and critical phenomena with LPPLS, demonstrates that targeting information related to phase transitions enables the forecast of financial bubbles and crashes punctuating the dynamics of prices.

Optimal healthcare decision making under multiple mathematical models: application in prostate cancer screening.

PubMed

Bertsimas, Dimitris; Silberholz, John; Trikalinos, Thomas

2018-03-01

Important decisions related to human health, such as screening strategies for cancer, need to be made without a satisfactory understanding of the underlying biological and other processes. Rather, they are often informed by mathematical models that approximate reality. Often multiple models have been made to study the same phenomenon, which may lead to conflicting decisions. It is natural to seek a decision making process that identifies decisions that all models find to be effective, and we propose such a framework in this work. We apply the framework in prostate cancer screening to identify prostate-specific antigen (PSA)-based strategies that perform well under all considered models. We use heuristic search to identify strategies that trade off between optimizing the average across all models' assessments and being "conservative" by optimizing the most pessimistic model assessment. We identified three recently published mathematical models that can estimate quality-adjusted life expectancy (QALE) of PSA-based screening strategies and identified 64 strategies that trade off between maximizing the average and the most pessimistic model assessments. All prescribe PSA thresholds that increase with age, and 57 involve biennial screening. Strategies with higher assessments with the pessimistic model start screening later, stop screening earlier, and use higher PSA thresholds at earlier ages. The 64 strategies outperform 22 previously published expert-generated strategies. The 41 most "conservative" ones remained better than no screening with all models in extensive sensitivity analyses. We augment current comparative modeling approaches by identifying strategies that perform well under all models, for various degrees of decision makers' conservativeness.

Early-late life trade-offs and the evolution of ageing in the wild.

PubMed

Lemaître, Jean-François; Berger, Vérane; Bonenfant, Christophe; Douhard, Mathieu; Gamelon, Marlène; Plard, Floriane; Gaillard, Jean-Michel

2015-05-07

Empirical evidence for declines in fitness components (survival and reproductive performance) with age has recently accumulated in wild populations, highlighting that the process of senescence is nearly ubiquitous in the living world. Senescence patterns are highly variable among species and current evolutionary theories of ageing propose that such variation can be accounted for by differences in allocation to growth and reproduction during early life. Here, we compiled 26 studies of free-ranging vertebrate populations that explicitly tested for a trade-off between performance in early and late life. Our review brings overall support for the presence of early-late life trade-offs, suggesting that the limitation of available resources leads individuals to trade somatic maintenance later in life for high allocation to reproduction early in life. We discuss our results in the light of two closely related theories of ageing-the disposable soma and the antagonistic pleiotropy theories-and propose that the principle of energy allocation roots the ageing process in the evolution of life-history strategies. Finally, we outline research topics that should be investigated in future studies, including the importance of natal environmental conditions in the study of trade-offs between early- and late-life performance and the evolution of sex-differences in ageing patterns. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Biclustering Learning of Trading Rules.

PubMed

Huang, Qinghua; Wang, Ting; Tao, Dacheng; Li, Xuelong

2015-10-01

Technical analysis with numerous indicators and patterns has been regarded as important evidence for making trading decisions in financial markets. However, it is extremely difficult for investors to find useful trading rules based on numerous technical indicators. This paper innovatively proposes the use of biclustering mining to discover effective technical trading patterns that contain a combination of indicators from historical financial data series. This is the first attempt to use biclustering algorithm on trading data. The mined patterns are regarded as trading rules and can be classified as three trading actions (i.e., the buy, the sell, and no-action signals) with respect to the maximum support. A modified K nearest neighborhood ( K -NN) method is applied to classification of trading days in the testing period. The proposed method [called biclustering algorithm and the K nearest neighbor (BIC- K -NN)] was implemented on four historical datasets and the average performance was compared with the conventional buy-and-hold strategy and three previously reported intelligent trading systems. Experimental results demonstrate that the proposed trading system outperforms its counterparts and will be useful for investment in various financial markets.

No Evidence of Trade-Off between Farm Efficiency and Resilience: Dependence of Resource-Use Efficiency on Land-Use Diversity

PubMed Central

Kahiluoto, Helena; Kaseva, Janne

2016-01-01

Efficiency in the use of resources stream-lined for expected conditions could lead to reduced system diversity and consequently endanger resilience. We tested the hypothesis of a trade-off between farm resource-use efficiency and land-use diversity. We applied stochastic frontier production models to assess the dependence of resource-use-efficiency on land-use diversity as illustrated by the Shannon-Weaver index. Total revenue in relation to use of capital, land and labour on the farms in Southern Finland with a size exceeding 30 ha was studied. The data were extracted from the Finnish Profitability Bookkeeping data. Our results indicate that there is either no trade-off or a negligible trade-off of no economic importance. The small dependence of resource-use efficiency on land-use diversity can be positive as well as negative. We conclude that diversification as a strategy to enhance farm resilience does not necessarily constrain resource-use efficiency. PMID:27662475

Trading strategies for distribution company with stochastic distributed energy resources

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

Zhang, Chunyu; Wang, Qi; Wang, Jianhui

2016-09-01

This paper proposes a methodology to address the trading strategies of a proactive distribution company (PDISCO) engaged in the transmission-level (TL) markets. A one-leader multi-follower bilevel model is presented to formulate the gaming framework between the PDISCO and markets. The lower-level (LL) problems include the TL day-ahead market and scenario-based real-time markets, respectively with the objectives of maximizing social welfare and minimizing operation cost. The upper-level (UL) problem is to maximize the PDISCO’s profit across these markets. The PDISCO’s strategic offers/bids interactively influence the outcomes of each market. Since the LL problems are linear and convex, while the UL problemmore » is non-linear and non-convex, an equivalent primal–dual approach is used to reformulate this bilevel model to a solvable mathematical program with equilibrium constraints (MPEC). The effectiveness of the proposed model is verified by case studies.« less

SUMC fault tolerant computer system

NASA Technical Reports Server (NTRS)

1980-01-01

The results of the trade studies are presented. These trades cover: establishing the basic configuration, establishing the CPU/memory configuration, establishing an approach to crosstrapping interfaces, defining the requirements of the redundancy management unit (RMU), establishing a spare plane switching strategy for the fault-tolerant memory (FTM), and identifying the most cost effective way of extending the memory addressing capability beyond the 64 K-bytes (K=1024) of SUMC-II B. The results of the design are compiled in Contract End Item (CEI) Specification for the NASA Standard Spacecraft Computer II (NSSC-II), IBM 7934507. The implementation of the FTM and memory address expansion.

Trade-off results and preliminary designs of Near-Term Hybrid Vehicles

NASA Technical Reports Server (NTRS)

Sandberg, J. J.

1980-01-01

Phase I of the Near-Term Hybrid Vehicle Program involved the development of preliminary designs of electric/heat engine hybrid passenger vehicles. The preliminary designs were developed on the basis of mission analysis, performance specification, and design trade-off studies conducted independently by four contractors. THe resulting designs involve parallel hybrid (heat engine/electric) propulsion systems with significant variation in component selection, power train layout, and control strategy. Each of the four designs is projected by its developer as having the potential to substitute electrical energy for 40% to 70% of the petroleum fuel consumed annually by its conventional counterpart.

Development of an Intellectual Property Strategy: Research Notes to Support Department of Defense Programs

DTIC Science & Technology

2014-10-01

USDA 2014]. 2.4.2 Terms of Trade Secret Ownership A trade secret owner is the person or entity “in whom or in which rightful legal or equitable title...federal works is governed by the DFARS. According to information from CENDI (Commerce, Energy, NASA , Defense Information Managers Group), the...acc.dau.mil/CommunityBrowser.aspx?id=431675 [ USDA 2014] U.S. Department of Agriculture. Proprietary Information and Trade Secrets. 2014. http

12 CFR 324.203 - Requirements for application of this subpart F.

Code of Federal Regulations, 2014 CFR

2014-01-01

... defined trading and hedging strategies for its trading positions that are approved by senior management of... FDIC-supervised institution will use to hedge the risk of the portfolio. (b) Management of covered positions—(1) Active management. An FDIC-supervised institution must have clearly defined policies and...

Fish Commoditization: Sustainability Strategies to Protect Living Fish

ERIC Educational Resources Information Center

Lam, Mimi E.; Pitcher, Tony J.

2012-01-01

The impacts of early fishing on aquatic ecosystems were minimal, as primitive technologies were used to harvest fish primarily for food. As fishing technology grew more sophisticated and human populations dispersed and expanded, local economies transitioned from subsistence to barter and trade. Expanded trade networks and mercantilization led to…

40 CFR 52.377 - Control strategy: Ozone.

Code of Federal Regulations, 2014 CFR

2014-07-01

... No. 1 issued to Northeast Nuclear Energy Company in Waterford on April 29, 1999. (li) Trading Agreement and Order No. 8107 Modification No. 2 issued to Northeast Nuclear Energy Company in Waterford on March 29, 2001. (lii) Trading Agreement and Order No. 8152 issued to Northeast Nuclear Energy Company in...

The Myth of Fair Prices: A Graphical Analysis.

ERIC Educational Resources Information Center

Yanchus, Dennis; de Vanssay, Xavier

2003-01-01

Illustrates how fair price policies can be explained to undergraduate students by applying simple graphical methods normally used in general equilibrium trade theory. Indicates that fair price strategies can be looked upon as a suboptimal device for redistributing the gains from trade as compared with a transfer of funds. (JEH)

An Economic Framework of Microbial Trade

PubMed Central

Mee, Michael T.

2015-01-01

A large fraction of microbial life on earth exists in complex communities where metabolic exchange is vital. Microbes trade essential resources to promote their own growth in an analogous way to countries that exchange goods in modern economic markets. Inspired by these similarities, we developed a framework based on general equilibrium theory (GET) from economics to predict the population dynamics of trading microbial communities. Our biotic GET (BGET) model provides an a priori theory of the growth benefits of microbial trade, yielding several novel insights relevant to understanding microbial ecology and engineering synthetic communities. We find that the economic concept of comparative advantage is a necessary condition for mutualistic trade. Our model suggests that microbial communities can grow faster when species are unable to produce essential resources that are obtained through trade, thereby promoting metabolic specialization and increased intercellular exchange. Furthermore, we find that species engaged in trade exhibit a fundamental tradeoff between growth rate and relative population abundance, and that different environments that put greater pressure on group selection versus individual selection will promote varying strategies along this growth-abundance spectrum. We experimentally tested this tradeoff using a synthetic consortium of Escherichia coli cells and found the results match the predictions of the model. This framework provides a foundation to study natural and engineered microbial communities through a new lens based on economic theories developed over the past century. PMID:26222307

Statistical modeling of crystalline silica exposure by trade in the construction industry using a database compiled from the literature.

PubMed

Sauvé, Jean-François; Beaudry, Charles; Bégin, Denis; Dion, Chantal; Gérin, Michel; Lavoué, Jérôme

2012-09-01

A quantitative determinants-of-exposure analysis of respirable crystalline silica (RCS) levels in the construction industry was performed using a database compiled from an extensive literature review. Statistical models were developed to predict work-shift exposure levels by trade. Monte Carlo simulation was used to recreate exposures derived from summarized measurements which were combined with single measurements for analysis. Modeling was performed using Tobit models within a multimodel inference framework, with year, sampling duration, type of environment, project purpose, project type, sampling strategy and use of exposure controls as potential predictors. 1346 RCS measurements were included in the analysis, of which 318 were non-detects and 228 were simulated from summary statistics. The model containing all the variables explained 22% of total variability. Apart from trade, sampling duration, year and strategy were the most influential predictors of RCS levels. The use of exposure controls was associated with an average decrease of 19% in exposure levels compared to none, and increased concentrations were found for industrial, demolition and renovation projects. Predicted geometric means for year 1999 were the highest for drilling rig operators (0.238 mg m(-3)) and tunnel construction workers (0.224 mg m(-3)), while the estimated exceedance fraction of the ACGIH TLV by trade ranged from 47% to 91%. The predicted geometric means in this study indicated important overexposure compared to the TLV. However, the low proportion of variability explained by the models suggests that the construction trade is only a moderate predictor of work-shift exposure levels. The impact of the different tasks performed during a work shift should also be assessed to provide better management and control of RCS exposure levels on construction sites.

Spatiotemporal assessment and trade-offs of multiple ecosystem services based on land use changes in Zengcheng, China.

PubMed

Sun, Xiao; Li, Feng

2017-12-31

Driven by rapid urbanization, land use change has become a significant factor influencing ecosystem services (ESs). To support the decision-making process of city planners and policy makers, assessing the spatiotemporal changes associated with multiple ESs is vital. In this study, we developed a general structure to assess the changes of multiple ESs in Zengcheng, China. A new index also was developed to measure the comprehensive ecosystem service (CES). Trade-offs of various ESs were analyzed by using correlation analysis. We then designed four alternate scenarios to explore the optimal land use strategies to increase the CES value and minimize trade-offs among various ESs. Results demonstrated that rapid expansion of built-up land and traffic land resulted in a decrease of CES in Zengcheng from 2003 to 2013. Although the water supply, water purification, and vegetable and fruit production services increased, the climate regulation, soil conservation, biodiversity protection, recreation opportunity and grain production services decreased during the ten-year period. Government should implement land use policies and ecological engineering measures to improve soil conservation in the northern region; recreation opportunity in the central region; and carbon storage, water purification, biodiversity protection and recreation opportunity in the southern region. Among all alternative scenarios, woodland buffer and soil conservation scenarios exhibit the highest CES values, indicating that policies such as the "Ecological corridor construction" project and the "Grain for Green" project should be implemented. However, a caveat is that these policies improve the ESs at the expense of food production due to significant trade-off relationships. To minimize the trade-offs, a more sustainable intensification of agriculture should be adopted to increase food production without decreasing other ESs or occupying additional land. The land use strategies and ecological engineering measures in this study can provide a reliable reference for sustainable development of other urbanized regions in China. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluating the efficacy of regionalisation in limiting high-risk livestock trade movements.

PubMed

Hidano, Arata; Carpenter, Tim E; Stevenson, Mark A; Gates, M Carolyn

2016-10-01

Many countries implement regionalisation as a measure to control economically important livestock diseases. Given that regionalisation highlights the difference in disease risk between animal subpopulations, this may discourage herd managers in low-risk areas from purchasing animals from high-risk areas to protect the disease-free status of their herds. Using bovine tuberculosis (bTB) in New Zealand as a case example, we develop a novel network simulation model to predict how much the frequency of cattle movements between different disease control areas (DCAs) could theoretically change if herd managers adopted the safest practices (preferentially purchasing cattle from areas with the lowest risk of bTB), if herd managers adopted the riskiest practices (preferentially purchasing cattle from areas with the greatest risk of bTB), or if herd managers made trade decisions completely at random (purchasing cattle without consideration for bTB disease risk). A modified configuration wiring algorithm was used in the network simulation model to preserve key temporal, spatial, and demographic attributes of cattle movement patterns. The simulated frequencies of cattle movements between DCAs in each of the three behavioural scenarios were compared with the actual frequency of cattle movements that occurred between 1st July 2010 and 30th June 2011. Our results showed that the observed frequency of cattle movements from high-risk areas into low-risk areas was significantly less than if trade decisions were made completely at random, but still significantly greater than if herd managers made the safest possible trade decisions. This suggests that while New Zealand cattle farmers may have adopted risk-averse trading behaviour in response to regionalisation, there are other underlying factors driving livestock trade, such as established supplier-buyer relationships and heterogeneous individual perceptions towards disease risk, which may reduce the potential efficacy of regionalisation as a disease control strategy. Physical constraints and socio-psychological factors that determine herd managers' livestock trading behaviour warrant further studies to better understand how herd managers respond to future livestock disease regulations. The flexibility of a network re-wiring framework presented in this study allows such a behavioural response to be incorporated into a disease simulation model, which will in turn facilitate a better evaluation of disease control strategies. Copyright © 2016 Elsevier B.V. All rights reserved.

QTL analysis of root morphology, flowering time, and yield reveals trade-offs in response to drought in Brassica napus.

PubMed

Fletcher, Richard S; Mullen, Jack L; Heiliger, Annie; McKay, John K

2015-01-01

Drought escape and dehydration avoidance represent alternative strategies for drought adaptation in annual crops. The mechanisms underlying these two strategies are reported to have a negative correlation, suggesting a trade-off. We conducted a quantitative trait locus (QTL) analysis of flowering time and root mass, traits representing each strategy, in Brassica napus to understand if a trade-off exists and what the genetic basis might be. Our field experiment used a genotyped population of doubled haploid lines and included both irrigated and rainfed treatments, allowing analysis of plasticity in each trait. We found strong genetic correlations among all traits, suggesting a trade-off among traits may exist. Summing across traits and treatments we found 20 QTLs, but many of these co-localized to two major QTLs, providing evidence that the trade-off is genetically constrained. To understand the mechanistic relationship between root mass, flowering time, and QTLs, we analysed the data by conditioning upon correlated traits. Our results suggest a causal model where such QTLs affect root mass directly as well as through their impacts on flowering time. Additionally, we used draft Brassica genomes to identify orthologues of well characterized Arabidopsis thaliana flowering time genes as candidate genes. This research provides valuable clues to breeding for drought adaptation as it is the first to analyse the inheritance of the root system in B. napus in relation to drought. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

The potential cost savings of implementing an inter-utility NO{sub x} trading program

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

Siegel, S.; Kalagnanam, J.

1995-12-31

Technology based standards such as RACT, which require the installation of a Reasonably Available Control Technology on a boiler by boiler basis have been the dominant factor driving electric utility NO{sub x} compliance plans. In this paper, the authors examine the cost savings of implementing NO{sub x} trading, an alternative market based strategy for reducing the emissions of nitrogen oxides (NO{sub x}) to achieve NO{sub x} reduction goals set under Title IV of the 1990 Clean Air Act. In order to estimate the potential cost savings of inter-utility NO{sub x} trading, the authors have used a combinatorial optimization approach tomore » identify boiler retrofits and operating parameters which yield efficient (i.e., the most cost effective) NO{sub x} abatement. In the formulation, annual emissions at individual boilers which are expensive to abate may exceed RACT levels by up to a factor of two thus allowing for trades with boilers which can abate in a more cost effective manner. The authors constrain total emissions in a trading region to be at or below the level obtained had all the boilers adopted RACT. Increasing the flexibility with which trades can occur has two main effects: (1) the cost effectiveness of meeting an aggregate reduction goal increases and (2) the spatial distribution of emissions shift relative to what it would have been under a strict RACT based compliance strategy. The authors estimate the magnitude of these effects for two Eastern electric utilities making intra and inter-utility NO{sub x} trades. Results indicate that the cost effectiveness of meeting RACT level reduction can be increased by as much as 38% under certain trading regimes.« less

Waterpipe industry products and marketing strategies: analysis of an industry trade exhibition

PubMed Central

Jawad, Mohammed; Nakkash, Rima T; Hawkins, Ben; Akl, Elie A

2016-01-01

Introduction Understanding product development and marketing strategies of transnational tobacco companies (TTCs) has been of vital importance in developing effective tobacco control policy. However, comparatively little is known of the waterpipe tobacco industry, which TTCs have recently entered. This study aimed to gain an understanding of waterpipe tobacco products and marketing strategies by visiting a waterpipe trade exhibition. Methods In April 2014 the first author attended an international waterpipe trade exhibition, recording descriptions of products and collecting all marketing items available. We described the purpose and function of all products, and performed a thematic analysis of messages in marketing material. Results We classified the waterpipe products into seven categories and noted product variation within categories. Electronic waterpipe products (which mimic electronic cigarettes) rarely appeared on waterpipe tobacco marketing material, but were displayed just as widely. Claims of reduced harm, safety and quality were paramount on marketing materials, regardless of whether they were promoting waterpipe tobacco, waterpipe tobacco-substitutes, electronic waterpipes or charcoal. Conclusions Waterpipe products are diverse in nature and are marketed as healthy and safe products. Furthermore, the development of electronic waterpipe products appear to be closely connected with the electronic cigarette industry, rather than the waterpipe tobacco manufacturers. Tobacco control policy must evolve to take account of the vast and expanding array of waterpipe products, and potentially also charcoal products developed for waterpipe smokers. We recommend tobacco-substitutes be classified as tobacco products. Continued surveillance of the waterpipe industry is warranted. PMID:26149455

Work-based physiological assessment of physically-demanding trades: a methodological overview.

PubMed

Taylor, Nigel A S; Groeller, Herb

2003-03-01

Technological advances, modified work practices, altered employment strategies, work-related injuries, and the rise in work-related litigation and compensation claims necessitate ongoing trade analysis research. Such research enables the identification and development of gender- and age-neutral skills, physiological attributes and employment standards required to satisfactorily perform critical trade tasks. This paper overviews a methodological approach which may be adopted when seeking to establish trade-specific physiological competencies for physically-demanding trades (occupations). A general template is presented for conducting a trade analyses within physically-demanding trades, such as those encountered within military or emergency service occupations. Two streams of analysis are recommended: the trade analysis and the task analysis. The former involves a progressive dissection of activities and skills into a series of specific tasks (elements), and results in a broad approximation of the types of trade duties, and the links between trade tasks. The latter, will lead to the determination of how a task is performed within a trade, and the physiological attributes required to satisfactorily perform that task. The approach described within this paper is designed to provide research outcomes which have high content, criterion-related and construct validities.

Trade-off among different anti-herbivore defence strategies along an altitudinal gradient

PubMed Central

Dostálek, Tomáš; Rokaya, Maan Bahadur; Maršík, Petr; Rezek, Jan; Skuhrovec, Jiří; Pavela, Roman; Münzbergová, Zuzana

2016-01-01

The type and intensity of plant–herbivore interactions are likely to be altered under climate change as a consequence of differential dispersal rates of plants and their herbivores. Here, we studied variation in herbivore damage on Salvia nubicola in the field and compared its growth and defence strategies against herbivores in controlled conditions using seeds from populations along a broad altitudinal gradient. Our work is one of the first studies to simultaneously measure complex intraspecific variation in plant growth, direct and indirect defences as well as plant tolerance (ability to regrow) as a consequence of herbivore attack simulated by clipping. In the field, we found that plants experienced higher herbivore pressure in lower altitudes. In the greenhouse, plants grown from seeds collected in lower-altitude populations grew better and produced a higher content of phenolic compounds (direct defence) and volatile organic compounds (indirect defence) in response to simulated herbivory. However, there were no differences in tolerance and effect of S. nubicola extracts on the model generalist herbivore Spodoptera littoralis (direct defence) along the altitudinal gradient. Although we found that S. nubicola developed a range of defence strategies, the strategies do not seem to be used simultaneously in all populations even though most of them are correlated with altitudinal gradient. Our finding is in agreement with the current knowledge that co-expression of multiple defences might be costly for a plant, since investment in defensive traits is assumed to reduce the resource availability for growth and reproduction. Our study thus shows the importance of simultaneous study of different defence strategies since understanding these trade-offs could be necessary for detecting the mechanisms by which plants are able to cope with future climate change. PMID:27169609

The Asian Correction Can Be Quantitatively Forecasted Using a Statistical Model of Fusion-Fission Processes.

PubMed

Teh, Boon Kin; Cheong, Siew Ann

2016-01-01

The Global Financial Crisis of 2007-2008 wiped out US$37 trillions across global financial markets, this value is equivalent to the combined GDPs of the United States and the European Union in 2014. The defining moment of this crisis was the failure of Lehman Brothers, which precipitated the October 2008 crash and the Asian Correction (March 2009). Had the Federal Reserve seen these crashes coming, they might have bailed out Lehman Brothers, and prevented the crashes altogether. In this paper, we show that some of these market crashes (like the Asian Correction) can be predicted, if we assume that a large number of adaptive traders employing competing trading strategies. As the number of adherents for some strategies grow, others decline in the constantly changing strategy space. When a strategy group grows into a giant component, trader actions become increasingly correlated and this is reflected in the stock price. The fragmentation of this giant component will leads to a market crash. In this paper, we also derived the mean-field market crash forecast equation based on a model of fusions and fissions in the trading strategy space. By fitting the continuous returns of 20 stocks traded in Singapore Exchange to the market crash forecast equation, we obtain crash predictions ranging from end October 2008 to mid-February 2009, with early warning four to six months prior to the crashes.

The Asian Correction Can Be Quantitatively Forecasted Using a Statistical Model of Fusion-Fission Processes

PubMed Central

Teh, Boon Kin; Cheong, Siew Ann

2016-01-01

The Global Financial Crisis of 2007-2008 wiped out US$37 trillions across global financial markets, this value is equivalent to the combined GDPs of the United States and the European Union in 2014. The defining moment of this crisis was the failure of Lehman Brothers, which precipitated the October 2008 crash and the Asian Correction (March 2009). Had the Federal Reserve seen these crashes coming, they might have bailed out Lehman Brothers, and prevented the crashes altogether. In this paper, we show that some of these market crashes (like the Asian Correction) can be predicted, if we assume that a large number of adaptive traders employing competing trading strategies. As the number of adherents for some strategies grow, others decline in the constantly changing strategy space. When a strategy group grows into a giant component, trader actions become increasingly correlated and this is reflected in the stock price. The fragmentation of this giant component will leads to a market crash. In this paper, we also derived the mean-field market crash forecast equation based on a model of fusions and fissions in the trading strategy space. By fitting the continuous returns of 20 stocks traded in Singapore Exchange to the market crash forecast equation, we obtain crash predictions ranging from end October 2008 to mid-February 2009, with early warning four to six months prior to the crashes. PMID:27706198

15 CFR 923.128 - Revisions to assessments and strategies.

Code of Federal Regulations, 2010 CFR

2010-01-01

... strategies. 923.128 Section 923.128 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign... COASTAL RESOURCE MANAGEMENT COASTAL ZONE MANAGEMENT PROGRAM REGULATIONS Coastal Zone Enhancement Grants Program § 923.128 Revisions to assessments and strategies. (a) A State, in consultation with the Assistant...

Strategies for Obtaining Obsidian in Pre-European Contact Era New Zealand

PubMed Central

McCoy, Mark D.; Carpenter, Jonathan

2014-01-01

Archaeological evidence of people's choices regarding how they supply themselves with obsidian through direct access and different types of exchanges gives us insight in to mobility, social networks, and property rights in the distant past. Here we use collections of obsidian artefacts that date to a period of endemic warfare among Maori during New Zealand's Late Period (1500–1769 A.D.) to determine what strategies people engaged in to obtain obsidian, namely (1) collecting raw material directly from a natural source, (2) informal trade and exchange, and (3) formal trade and exchange. These deposits represent a good cross-section of Late Period archaeology, including primary working of raw material at a natural source (Helena Bay), undefended sites where people discarded rubbish and worked obsidian (Bream Head), and a heavily fortified site (Mt. Wellington). We find that most of the obsidian described here was likely obtained directly from natural sources, especially those located on off-shore islands within about 60–70 km of sites. A smaller amount comes from blocks of material transported from an off-shore island a greater distance away, called Mayor Island, in a formal trade and exchange network. This study demonstrates the value of conducting tandem lithic technology and geochemical sourcing studies to understand how people create and maintain social networks during periods of warfare. PMID:24416213

Industrial Sector Energy Efficiency Modeling (ISEEM) Framework Documentation

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

Karali, Nihan; Xu, Tengfang; Sathaye, Jayant

2012-12-12

The goal of this study is to develop a new bottom-up industry sector energy-modeling framework with an agenda of addressing least cost regional and global carbon reduction strategies, improving the capabilities and limitations of the existing models that allows trading across regions and countries as an alternative.

Designing ARVs Patent Pool Up to Trade & Policy Evolutionary Dynamics

PubMed Central

Dionisio, Daniele; Racalbuto, Vincenzo; Messeri, Daniela

2010-01-01

Patent pools for second and third-line Fixed Dose Combination (FDC) antiretroviral drugs (ARVs) should not be delayed as they are instrumental to urgent public health needs in the under-served markets. Nonetheless, multinational originator companies still seem to perceive patent pooling for ARVs as a minefield that would offer the generic competitors lots of deeply exploitable opportunities, to the detriment of patent owner’s rights. This paper analyses the brand industry concerns, while looking for a strategy up to a really equitable and free world market, without any discrimination between end-users in wealthy and resource-limited countries. This strategy would urge partnerships between originator companies first to make newer FDC ARVs quickly available and allow patent pool agreements with generic counterparts to be negotiated straight afterwards. The patent pool strategy highlighted in this paper would assert the primacy of health over for-profit policies, while aligning with the 61st WHO’s Assembly recommendations and G7, G8 and World Trade Organisation’s warnings and pledges against trade protectionism. PMID:20200604

COMSATCOM service technical baseline strategy development approach using PPBW concept

NASA Astrophysics Data System (ADS)

Nguyen, Tien M.; Guillen, Andy T.

2016-05-01

This paper presents an innovative approach to develop a Commercial Satellite Communications (COMSATCOM) service Technical Baseline (TB) and associated Program Baseline (PB) strategy using Portable Pool Bandwidth (PPBW) concept. The concept involves trading of the purchased commercial transponders' Bandwidths (BWs) with existing commercial satellites' bandwidths participated in a "designated pool bandwidth"3 according to agreed terms and conditions. Space Missile Systems Center (SMC) has been implementing the Better Buying Power (BBP 3.0) directive4 and recommending the System Program Offices (SPO) to own the Program and Technical Baseline (PTB) [1, 2] for the development of flexible acquisition strategy and achieving affordability and increased in competition. This paper defines and describes the critical PTB parameters and associated requirements that are important to the government SPO for "owning" an affordable COMSATCOM services contract using PPBW trading concept. The paper describes a step-by-step approach to optimally perform the PPBW trading to meet DoD and its stakeholders (i) affordability requirement, and (ii) fixed and variable bandwidth requirements by optimizing communications performance, cost and PPBW accessibility in terms of Quality of Services (QoS), Bandwidth Sharing Ratio (BSR), Committed Information Rate (CIR), Burstable Information Rate (BIR), Transponder equivalent bandwidth (TPE) and transponder Net Presence Value (NPV). The affordable optimal solution that meets variable bandwidth requirements will consider the operating and trading terms and conditions described in the Fair Access Policy (FAP).

Turn Your Key--Reducing Truck Idling

ERIC Educational Resources Information Center

MacRae, Gareth; Stockport, Tina

2008-01-01

As Australia enters the era of emissions trading schemes, strategies to further curb emissions will grow in importance. At the same time, a national emissions trading scheme is set to be introduced whilst the country is set to increase its dependency and volume of road transport in years to come. This raises a doubly important question for…

Trade-offs between constitutive and induced defences drive geographical and climatic clines in pine chemical defences.

PubMed

Moreira, Xoaquín; Mooney, Kailen A; Rasmann, Sergio; Petry, William K; Carrillo-Gavilán, Amparo; Zas, Rafael; Sampedro, Luis

2014-05-01

There is increasing evidence that geographic and climatic clines drive the patterns of plant defence allocation and defensive strategies. We quantified early growth rate and both constitutive and inducible chemical defences of 18 Pinaceae species in a common greenhouse environment and assessed their defensive allocation with respect to each species' range across climatic gradients spanning 31° latitude and 2300 m elevation. Constitutive defences traded-off with induced defences, and these defensive strategies were associated with growth rate such that slow-growing species invested more in constitutive defence, whereas fast-growing species invested more in inducible defence. The position of each pine species along this trade-off axis was in turn associated with geography; moving poleward and to higher elevations, growth rate and inducible defences decreased, while constitutive defence increased. These geographic patterns in plant defence were most strongly associated with variation in temperature. Climatic and geographical clines thus act as drivers of defence profiles by mediating the constraints imposed by trade-offs, and this dynamic underlays global patterns of defence allocation.

77 FR 8216 - Request for Stakeholder Comments on “National Travel and Tourism Strategy”

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-14

... ``National Travel and Tourism Strategy'' AGENCY: International Trade Administration, Department of Commerce... ``National Travel and Tourism Strategy'' (``Strategy''), to be produced by the Task Force on Travel and... sent to: Tourism[email protected] . Written comments may be sent to: Jennifer Pilat, 1401...

77 FR 67847 - Self-Regulatory Organizations; Chicago Board Options Exchange, Incorporated; Notice of Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-14

... ex-dividend.\\5\\ Dividend strategy transactions are only executed by Market-Makers. The Exchange... Sliding Scale volume thresholds. However, because only Market- Makers execute dividend strategy trades and... from the list of strategy executions for which fee caps apply. Under the Exchange's current Fees...

Modeling the stylized facts in finance through simple nonlinear adaptive systems

PubMed Central

Hommes, Cars H.

2002-01-01

Recent work on adaptive systems for modeling financial markets is discussed. Financial markets are viewed as evolutionary systems between different, competing trading strategies. Agents are boundedly rational in the sense that they tend to follow strategies that have performed well, according to realized profits or accumulated wealth, in the recent past. Simple technical trading rules may survive evolutionary competition in a heterogeneous world where prices and beliefs co-evolve over time. Evolutionary models can explain important stylized facts, such as fat tails, clustered volatility, and long memory, of real financial series. PMID:12011401

Design of Tactical Support Strategies in Military Logistics: Trade-offs Between Efficiency and Effectiveness. A Column and Cut Generation Modeling Methods

DTIC Science & Technology

2011-12-01

problems need to be addressed in the design of military logis- tics networks. The design problem includes strategic decisions, such as the location of...military strategic logistics [11–13]. In this study, we focus on the design of tactical logistics strategies, which achieve different optimal balances...is clear that our problem is N P−Hard 1 since it generalizes the CVPR and the BPP . Different solutions to handle the loading and routing of

Market Imitation and Win-Stay Lose-Shift Strategies Emerge as Unintended Patterns in Market Direction Guesses.

PubMed

Gutiérrez-Roig, Mario; Segura, Carlota; Duch, Jordi; Perelló, Josep

2016-01-01

Decisions made in our everyday lives are based on a wide variety of information so it is generally very difficult to assess what are the strategies that guide us. Stock market provides a rich environment to study how people make decisions since responding to market uncertainty needs a constant update of these strategies. For this purpose, we run a lab-in-the-field experiment where volunteers are given a controlled set of financial information -based on real data from worldwide financial indices- and they are required to guess whether the market price would go "up" or "down" in each situation. From the data collected we explore basic statistical traits, behavioural biases and emerging strategies. In particular, we detect unintended patterns of behavior through consistent actions, which can be interpreted as Market Imitation and Win-Stay Lose-Shift emerging strategies, with Market Imitation being the most dominant. We also observe that these strategies are affected by external factors: the expert advice, the lack of information or an information overload reinforce the use of these intuitive strategies, while the probability to follow them significantly decreases when subjects spends more time to make a decision. The cohort analysis shows that women and children are more prone to use such strategies although their performance is not undermined. Our results are of interest for better handling clients expectations of trading companies, to avoid behavioural anomalies in financial analysts decisions and to improve not only the design of markets but also the trading digital interfaces where information is set down. Strategies and behavioural biases observed can also be translated into new agent based modelling or stochastic price dynamics to better understand financial bubbles or the effects of asymmetric risk perception to price drops.

Market Imitation and Win-Stay Lose-Shift Strategies Emerge as Unintended Patterns in Market Direction Guesses

PubMed Central

Segura, Carlota; Duch, Jordi; Perelló, Josep

2016-01-01

Decisions made in our everyday lives are based on a wide variety of information so it is generally very difficult to assess what are the strategies that guide us. Stock market provides a rich environment to study how people make decisions since responding to market uncertainty needs a constant update of these strategies. For this purpose, we run a lab-in-the-field experiment where volunteers are given a controlled set of financial information -based on real data from worldwide financial indices- and they are required to guess whether the market price would go “up” or “down” in each situation. From the data collected we explore basic statistical traits, behavioural biases and emerging strategies. In particular, we detect unintended patterns of behavior through consistent actions, which can be interpreted as Market Imitation and Win-Stay Lose-Shift emerging strategies, with Market Imitation being the most dominant. We also observe that these strategies are affected by external factors: the expert advice, the lack of information or an information overload reinforce the use of these intuitive strategies, while the probability to follow them significantly decreases when subjects spends more time to make a decision. The cohort analysis shows that women and children are more prone to use such strategies although their performance is not undermined. Our results are of interest for better handling clients expectations of trading companies, to avoid behavioural anomalies in financial analysts decisions and to improve not only the design of markets but also the trading digital interfaces where information is set down. Strategies and behavioural biases observed can also be translated into new agent based modelling or stochastic price dynamics to better understand financial bubbles or the effects of asymmetric risk perception to price drops. PMID:27532219

Alternative Growth and Defensive Strategies Reveal Potential and Gender Specific Trade-Offs in Dioecious Plants Salix paraplesia to Nutrient Availability

PubMed Central

Jiang, Hao; Zhang, Sheng; Lei, Yanbao; Xu, Gang; Zhang, Dan

2016-01-01

Population sex ratios of many dioecious plants in nature are biased. This may be attributed to sexually different resource demands and adaptive capacity. In male-biasedPopulus, males often display stronger physiological adaptation than females. Interestingly, Populus and Salix, belonging to Salicaceae, display an opposite biased sex ratio, especially in nutrient-poor environmental conditions. Do female willows have a greater tolerance to nutrient deficiency than males? In this study, we investigated the growth and defensive strategies of Salix paraplesia cuttings, which were grown with high and low soil fertility for about 140 days over one growing season. Results suggest that different strategies for biomass allocation may result in sexually different defense capacities and trade-offs between growth and defense. Females are likely to adopt radical strategies, overdrawing on available resources to satisfy both growth and defense, which seems to be more like a gamble compared with males. It is also suggested that females may have an extra mechanism to compensate for the investment in growth under nutrient-poor conditions. In summary, the results may help focus restoration efforts on sex selection such that a moderate increase in female willow quantity could increase the resistance and resilience of willow populations to early sporadic desertification. PMID:27489556

Effect of Power Exchange of India: An Overview and Key Issues

NASA Astrophysics Data System (ADS)

Singh, A.; Chauhan, D. S.; Upadhdhyay, K. G.

2013-09-01

There stands no guarantee that if potential market participants are simply provided with the opportunity for trading electricity, there shall be an efficient wholesale electricity market. India, as well as various other developed countries, relies on voluntary agreements as far as electricity trading is concerned. Self, private initiatives to standardize and commodities contracts play an important role in increasing the trading volume to improve efficiency, in developed countries. In accordance with their experiences, this paper suggested a specific strategy to promote bilateral/OTC trading; hence, India needed to develop a master agreement for electricity contracts. This paper discusses that the creating power exchange for short-term trading in the spot market materializing the contract for the convenience of market participants stands particularly important and henceforth is a necessary factor to make sure that spot market is workable and competitive prior to developing a financial contract for electricity trading.

Metabolic enzyme cost explains variable trade-offs between microbial growth rate and yield

PubMed Central

Ferris, Michael; Bruggeman, Frank J.

2018-01-01

Microbes may maximize the number of daughter cells per time or per amount of nutrients consumed. These two strategies correspond, respectively, to the use of enzyme-efficient or substrate-efficient metabolic pathways. In reality, fast growth is often associated with wasteful, yield-inefficient metabolism, and a general thermodynamic trade-off between growth rate and biomass yield has been proposed to explain this. We studied growth rate/yield trade-offs by using a novel modeling framework, Enzyme-Flux Cost Minimization (EFCM) and by assuming that the growth rate depends directly on the enzyme investment per rate of biomass production. In a comprehensive mathematical model of core metabolism in E. coli, we screened all elementary flux modes leading to cell synthesis, characterized them by the growth rates and yields they provide, and studied the shape of the resulting rate/yield Pareto front. By varying the model parameters, we found that the rate/yield trade-off is not universal, but depends on metabolic kinetics and environmental conditions. A prominent trade-off emerges under oxygen-limited growth, where yield-inefficient pathways support a 2-to-3 times higher growth rate than yield-efficient pathways. EFCM can be widely used to predict optimal metabolic states and growth rates under varying nutrient levels, perturbations of enzyme parameters, and single or multiple gene knockouts. PMID:29451895

The role of fecundity and reproductive effort in defining life-history strategies of North American freshwater mussels.

PubMed

Haag, Wendell R

2013-08-01

Selection is expected to optimize reproductive investment resulting in characteristic trade-offs among traits such as brood size, offspring size, somatic maintenance, and lifespan; relative patterns of energy allocation to these functions are important in defining life-history strategies. Freshwater mussels are a diverse and imperiled component of aquatic ecosystems, but little is known about their life-history strategies, particularly patterns of fecundity and reproductive effort. Because mussels have an unusual life cycle in which larvae (glochidia) are obligate parasites on fishes, differences in host relationships are expected to influence patterns of reproductive output among species. I investigated fecundity and reproductive effort (RE) and their relationships to other life-history traits for a taxonomically broad cross section of North American mussel diversity. Annual fecundity of North American mussel species spans nearly four orders of magnitude, ranging from < 2000 to 10 million, but most species have considerably lower fecundity than previous generalizations, which portrayed the group as having uniformly high fecundity (e.g. > 200000). Estimates of RE also were highly variable, ranging among species from 0.06 to 25.4%. Median fecundity and RE differed among phylogenetic groups, but patterns for these two traits differed in several ways. For example, the tribe Anodontini had relatively low median fecundity but had the highest RE of any group. Within and among species, body size was a strong predictor of fecundity and explained a high percentage of variation in fecundity among species. Fecundity showed little relationship to other life-history traits including glochidial size, lifespan, brooding strategies, or host strategies. The only apparent trade-off evident among these traits was the extraordinarily high fecundity of Leptodea, Margaritifera, and Truncilla, which may come at a cost of greatly reduced glochidial size; there was no relationship between fecundity and glochidial size for the remaining 61 species in the dataset. In contrast to fecundity, RE showed evidence of a strong trade-off with lifespan, which was negatively related to RE. The raw number of glochidia produced may be determined primarily by physical and energetic constraints rather than selection for optimal output based on differences in host strategies or other traits. By integrating traits such as body size, glochidial size, and fecundity, RE appears more useful in defining mussel life-history strategies. Combined with trade-offs between other traits such as growth, lifespan, and age at maturity, differences in RE among species depict a broad continuum of divergent strategies ranging from strongly r-selected species (e.g. tribe Anodontini and some Lampsilini) to K-selected species (e.g. tribes Pleurobemini and Quadrulini; family Margaritiferidae). Future studies of reproductive effort in an environmental and life-history context will be useful for understanding the explosive radiation of this group of animals in North America and will aid in the development of effective conservation strategies. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Uncertainty analysis for effluent trading planning using a Bayesian estimation-based simulation-optimization modeling approach.

PubMed

Zhang, J L; Li, Y P; Huang, G H; Baetz, B W; Liu, J

2017-06-01

In this study, a Bayesian estimation-based simulation-optimization modeling approach (BESMA) is developed for identifying effluent trading strategies. BESMA incorporates nutrient fate modeling with soil and water assessment tool (SWAT), Bayesian estimation, and probabilistic-possibilistic interval programming with fuzzy random coefficients (PPI-FRC) within a general framework. Based on the water quality protocols provided by SWAT, posterior distributions of parameters can be analyzed through Bayesian estimation; stochastic characteristic of nutrient loading can be investigated which provides the inputs for the decision making. PPI-FRC can address multiple uncertainties in the form of intervals with fuzzy random boundaries and the associated system risk through incorporating the concept of possibility and necessity measures. The possibility and necessity measures are suitable for optimistic and pessimistic decision making, respectively. BESMA is applied to a real case of effluent trading planning in the Xiangxihe watershed, China. A number of decision alternatives can be obtained under different trading ratios and treatment rates. The results can not only facilitate identification of optimal effluent-trading schemes, but also gain insight into the effects of trading ratio and treatment rate on decision making. The results also reveal that decision maker's preference towards risk would affect decision alternatives on trading scheme as well as system benefit. Compared with the conventional optimization methods, it is proved that BESMA is advantageous in (i) dealing with multiple uncertainties associated with randomness and fuzziness in effluent-trading planning within a multi-source, multi-reach and multi-period context; (ii) reflecting uncertainties existing in nutrient transport behaviors to improve the accuracy in water quality prediction; and (iii) supporting pessimistic and optimistic decision making for effluent trading as well as promoting diversity of decision alternatives. Copyright © 2017 Elsevier Ltd. All rights reserved.

Trade liberalization and the diet transition: a public health response.

PubMed

Rayner, Geof; Hawkes, Corinna; Lang, Tim; Bello, Walden

2006-12-01

Trade liberalization remains at the forefront of debates around globalization, particularly around the impact on agriculture and food. These debates, which often focus on how poorer countries can 'trade their way' out of poverty, pay limited attention to dietary health, especially in the light of the WHO's Global Strategy for Diet, Physical Activity and Health (2004), which warned that future health burdens will be increasingly determined by diet-related chronic diseases. This article examines the diet transition as the absent factor within debates on liberalizing trade and commerce. We describe the evolution of trade agreements, noting those relevant to food. We review the association between trade liberalization and changes in the global dietary and disease profile. We illustrate some of the complex linkages between trade liberalization and the 'diet transition', illustrated by factors such as foreign direct investment, supermarketization and cultural change. Finally, we offer three scenarios for change, suggesting the need for more effective 'food governance' and engagement by public health advocates in policy making in the food and agriculture arena.

Advancing Public Health on the Changing Global Trade and Investment Agenda

PubMed Central

Thow, Anne Marie; Gleeson, Deborah

2017-01-01

Concerns regarding the Trans-Pacific Partnership (TPP) have raised awareness about the negative public health impacts of trade and investment agreements. In the past decade, we have learned much about the implications of trade agreements for public health: reduced equity in access to health services; increased flows of unhealthy commodities; limits on access to medicines; and constrained policy space for health. Getting health on the trade agenda continues to prove challenging, despite some progress in moving towards policy coherence. Recent changes in trade and investment agendas highlight an opportunity for public health researchers and practitioners to engage in highly politicized debates about how future economic policy can protect and support equitable public health outcomes. To fulfil this opportunity, public health attention now needs to turn to strengthening policy coherence between trade and health, and identifying how solutions can be implemented. Key strategies include research agendas that address politics and power, and capacity building for both trade and health officials. PMID:28812819

Corticosterone manipulation reveals differences in hierarchical organization of multidimensional reproductive trade-offs in r-strategist and K-strategist females.

PubMed

Lancaster, L T; Hazard, L C; Clobert, J; Sinervo, B R

2008-03-01

Life history trade-offs are often hierarchical with decisions at one level affecting lower level trade-offs. We investigated trade-off structure in female side-blotched lizards (Uta stansburiana), which exhibit two evolved strategies: yellow-throated females are K-strategists and orange-throated are r-strategists. Corticosterone treatment was predicted to differentially organize these females' reproductive decisions. Corticosterone-treated yellow females suppressed reproduction but survived well, and augmented egg mass without decreasing clutch size. Conversely, corticosterone enhanced mortality and reproductive rates in orange females, and increased egg mass only after lengthy exposure. Corticosterone did not affect post-laying condition, suggesting that corticosterone increased egg mass through enhanced energy acquisition (income breeding). Corticosterone enhanced survival of lightweight females, but decreased survival of heavy females, introducing a foraging vs. predation trade-off. We conclude that rather than being a direct, functional relationship, observed trade-offs between offspring size and number represent evolved differences in hierarchical organization of multidimensional trade-offs, particularly in response to stress.

An Emerging Role for Numerical Modelling in Wildfire Behavior Research: Explorations, Explanations, and Hypothesis Development

NASA Astrophysics Data System (ADS)

Linn, R.; Winterkamp, J.; Canfield, J.; Sauer, J.; Dupuy, J. L.; Finney, M.; Hoffman, C.; Parsons, R.; Pimont, F.; Sieg, C.; Forthofer, J.

2014-12-01

The human capacity for altering the water cycle has been well documented and given the expected change due to population, income growth, biofuels, climate, and associated land use change, there remains great uncertainty in both the degree of increased pressure on land and water resources and in our ability to adapt to these changes. Alleviating regional shortages in water supply can be carried out in a spatial hierarchy through i) direct trade of water between all regions, ii) development of infrastructure to improve water availability within regions (e.g. impounding rivers), iii) via inter-basin hydrological transfer between neighboring regions and, iv) via virtual water trade. These adaptation strategies can be managed via market trade in water and commodities to identify those strategies most likely to be adopted. This work combines the physically-based University of New Hampshire Water Balance Model (WBM) with the macro-scale Purdue University Simplified International Model of agricultural Prices Land use and the Environment (SIMPLE) to explore the interaction of supply and demand for fresh water globally. In this work we use a newly developed grid cell-based version of SIMPLE to achieve a more direct connection between the two modeling paradigms of physically-based models with optimization-driven approaches characteristic of economic models. We explore questions related to the global and regional impact of water scarcity and water surplus on the ability of regions to adapt to future change. Allowing for a variety of adaptation strategies such as direct trade of water and expanding the built water infrastructure, as well as indirect trade in commodities, will reduce overall global water stress and, in some regions, significantly reduce their vulnerability to these future changes.

A multi-objective decision-making approach to the journal submission problem.

PubMed

Wong, Tony E; Srikrishnan, Vivek; Hadka, David; Keller, Klaus

2017-01-01

When researchers complete a manuscript, they need to choose a journal to which they will submit the study. This decision requires to navigate trade-offs between multiple objectives. One objective is to share the new knowledge as widely as possible. Citation counts can serve as a proxy to quantify this objective. A second objective is to minimize the time commitment put into sharing the research, which may be estimated by the total time from initial submission to final decision. A third objective is to minimize the number of rejections and resubmissions. Thus, researchers often consider the trade-offs between the objectives of (i) maximizing citations, (ii) minimizing time-to-decision, and (iii) minimizing the number of resubmissions. To complicate matters further, this is a decision with multiple, potentially conflicting, decision-maker rationalities. Co-authors might have different preferences, for example about publishing fast versus maximizing citations. These diverging preferences can lead to conflicting trade-offs between objectives. Here, we apply a multi-objective decision analytical framework to identify the Pareto-front between these objectives and determine the set of journal submission pathways that balance these objectives for three stages of a researcher's career. We find multiple strategies that researchers might pursue, depending on how they value minimizing risk and effort relative to maximizing citations. The sequences that maximize expected citations within each strategy are generally similar, regardless of time horizon. We find that the "conditional impact factor"-impact factor times acceptance rate-is a suitable heuristic method for ranking journals, to strike a balance between minimizing effort objectives and maximizing citation count. Finally, we examine potential co-author tension resulting from differing rationalities by mapping out each researcher's preferred Pareto front and identifying compromise submission strategies. The explicit representation of trade-offs, especially when multiple decision-makers (co-authors) have different preferences, facilitates negotiations and can support the decision process.

A multi-objective decision-making approach to the journal submission problem

PubMed Central

Hadka, David; Keller, Klaus

2017-01-01

When researchers complete a manuscript, they need to choose a journal to which they will submit the study. This decision requires to navigate trade-offs between multiple objectives. One objective is to share the new knowledge as widely as possible. Citation counts can serve as a proxy to quantify this objective. A second objective is to minimize the time commitment put into sharing the research, which may be estimated by the total time from initial submission to final decision. A third objective is to minimize the number of rejections and resubmissions. Thus, researchers often consider the trade-offs between the objectives of (i) maximizing citations, (ii) minimizing time-to-decision, and (iii) minimizing the number of resubmissions. To complicate matters further, this is a decision with multiple, potentially conflicting, decision-maker rationalities. Co-authors might have different preferences, for example about publishing fast versus maximizing citations. These diverging preferences can lead to conflicting trade-offs between objectives. Here, we apply a multi-objective decision analytical framework to identify the Pareto-front between these objectives and determine the set of journal submission pathways that balance these objectives for three stages of a researcher’s career. We find multiple strategies that researchers might pursue, depending on how they value minimizing risk and effort relative to maximizing citations. The sequences that maximize expected citations within each strategy are generally similar, regardless of time horizon. We find that the “conditional impact factor”—impact factor times acceptance rate—is a suitable heuristic method for ranking journals, to strike a balance between minimizing effort objectives and maximizing citation count. Finally, we examine potential co-author tension resulting from differing rationalities by mapping out each researcher’s preferred Pareto front and identifying compromise submission strategies. The explicit representation of trade-offs, especially when multiple decision-makers (co-authors) have different preferences, facilitates negotiations and can support the decision process. PMID:28582430

Sustainable Street Vendors Spatial Zoning Models in Surakarta

NASA Astrophysics Data System (ADS)

Rahayu, M. J.; Putri, R. A.; Rini, E. F.

2018-02-01

Various strategies that have been carried out by Surakarta’s government to organize street vendors have not achieved the goal of street vendors’ arrangement comprehensively. The street vendors arrangement strategy consists of physical (spatial) and non-physical. One of the physical arrangements is to define the street vendor’s zoning. Based on the street vendors’ characteristics, there are two alternative locations of stabilization (as one kind of street vendors’ arrangement) that can be used. The aim of this study is to examine those alternative locations to set the street vendor’s zoning models. Quatitative method is used to formulate the spatial zoning model. The street vendor’s zoning models are formulated based on two approaches, which are the distance to their residences and previous trading locations. Geographic information system is used to indicate all street vendors’ residences and trading locations based on their type of goods. Through proximity point distance tool on ArcGIS, we find the closeness of residential location and previous trading location with the alternative location of street vendors’ stabilization. The result shows that the location was chosen by the street vendors to sell their goods mainly consider the proximity to their homes. It also shows street vendor’s zoning models which based on the type of street vendor’s goods.

77 FR 38117 - Self-Regulatory Organizations; NYSE Amex LLC; Order Granting Approval of Proposed Rule Change To...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-26

... monitoring of the Fund's sub-advisors; (ii) the assessment of performance and potential needs to modify strategy or change sub- advisors; (iii) the determination of the Fund's administrative policies; (iv) the... trading advisor (``CTA'') with the Commodity Futures Trading Commission (``CFTC'') and is a member of the...

Life-history strategies of North American elk: trade-offs associated with reproduction and survival

Treesearch

Sabrina Morano; Kelley M. Stewart; James S. Sedinger; Christopher A. Nicolai; Marty Vavra

2013-01-01

The principle of energy allocation states that individuals should attempt to maximize fitness by allocating resources optimally among growth, maintenance, and reproduction. Such allocation may result in trade-offs between survival and reproduction, or between current and future reproduction. We used a marked population of North American elk (Cervus elaphus...

Advertising and the Public Interest. A Staff Report to the Federal Trade Commission.

ERIC Educational Resources Information Center

Howard, John A.; Hulbert, James

The advertising industry in the United States is thoroughly analyzed in this comprehensive report. The report was prepared mostly from the transcripts of the Federal Trade Commission's (FTC) hearings on Modern Advertising Practices. The basic structure of the industry as well as its role in marketing strategy is reviewed and some interesting…

Export Now: A Practical Guide for U.S. Minority and Small Business Exporters.

ERIC Educational Resources Information Center

American Association of Community and Junior Colleges, Washington, DC.

This guidebook was designed to orient minority entrepreneurs to the basics of international trade. Market research and strategy are examined, as well as finance, contract negotiations, trade logistics, and business communications. Part I acknowledges that small firms often lack the resources to take even the first step in developing the knowledge,…

Trade Unions, Collective Bargaining and Reduced Working Time: A Critical Assessment.

ERIC Educational Resources Information Center

Rathkey, Paul

1986-01-01

In this article, the intention is to examine the development of the trade union approach to working time, assess its successes and failures, and seek an understanding of the movement toward reduced working time. From that assessment, it is argued that prevailing strategies are unlikely to bear dividends in terms of their own objectives--the…

Simulating Water Markets to Help Design Water Rights Regimes

NASA Astrophysics Data System (ADS)

Harou, J. J.; Erfani, T.; Huskova, I.; Binions, O.

2012-12-01

In many catchments in England no further licenses are available from the Environmental regulator that provides them. The possibility of trading water between license holders has been recognized as a potentially effective and economically efficient strategy to mitigate increasing scarcity. Although trading licenses has been possible since several years, it very rarely happens (roughly 50 trades in 8 years). Several barriers to trade exist including lack of sufficient and prolonged scarcity, license-holder unwillingness to risk future renewal, likelihood license will be downgraded during a trade, duration of time required for approving a trade, etc. Regulators seek to make policy changes so that their inability to grant new licenses will not harm the local and national economy. What policy changes will most cost-effectively increase trading and allow it to effectively reduce the economic cost of scarcity events? A screening tool that could help evaluate problems and advantages of different regulatory solutions, and that could serve to test, assuming transaction costs can be quantified, their effect on trading under specific conditions would be useful. We propose such a water market simulator that predicts economically efficient pair-wise trade (between willing buyers and sellers) and represents the interaction of trades with natural hydrological flows, engineered infrastructure and a particular regulatory regime. The model emulates license-holders' willingness to engage in short-term trade transactions. In their initial form different 'agents' (license holders) are represented using an economic benefit function of water use which is supplemented by rules to represent behavioral or other characteristics of realistic system behavior. A case study based on the river Ouse basin (UK) is made to test the model. The model simulates the catchment weekly over several years considering reservoirs and pair-wise specific transaction costs. Several regulatory policies are tested by evaluating their possible impact on transaction costs and then verifying impact on the number and type of predicted transactions.

Trade-offs across space, time, and ecosystem services

USGS Publications Warehouse

Rodriguez, J.P.; Beard, T.D.; Bennett, E.M.; Cumming, Graeme S.; Cork, S.J.; Agard, J.; Dobson, A.P.; Peterson, G.D.

2006-01-01

Ecosystem service (ES) trade-offs arise from management choices made by humans, which can change the type, magnitude, and relative mix of services provided by ecosystems. Trade-offs occur when the provision of one ES is reduced as a consequence of increased use of another ES. In some cases, a trade-off may be an explicit choice; but in others, trade-offs arise without premeditation or even awareness that they are taking place. Trade-offs in ES can be classified along three axes: spatial scale, temporal scale, and reversibility. Spatial scale refers to whether the effects of the trade-off are felt locally or at a distant location. Temporal scale refers to whether the effects take place relatively rapidly or slowly. Reversibility expresses the likelihood that the perturbed ES may return to its original state if the perturbation ceases. Across all four Millennium Ecosystem Assessment scenarios and selected case study examples, trade-off decisions show a preference for provisioning, regulating, or cultural services (in that order). Supporting services are more likely to be "taken for granted." Cultural ES are almost entirely unquantified in scenario modeling; therefore, the calculated model results do not fully capture losses of these services that occur in the scenarios. The quantitative scenario models primarily capture the services that are perceived by society as more important - provisioning and regulating ecosystem services - and thus do not fully capture trade-offs of cultural and supporting services. Successful management policies will be those that incorporate lessons learned from prior decisions into future management actions. Managers should complement their actions with monitoring programs that, in addition to monitoring the short-term provisions of services, also monitor the long-term evolution of slowly changing variables. Policies can then be developed to take into account ES trade-offs at multiple spatial and temporal scales. Successful strategies will recognize the inherent complexities of ecosystem management and will work to develop policies that minimize the effects of ES trade-offs. Copyright ?? 2006 by the author(s).

Tools of the Trade: Effective Strategies To Support the Collaboration of Educators in Rural Schools.

ERIC Educational Resources Information Center

Salyer, B. Keith; Thyfault, Alberta; Curran, Christina

This paper discusses strategies with the potential to enhance student learning, teacher collaboration, building management, and joy within the rural school setting. With the goal of fostering education that makes sense to students, three general categories of strategies are considered: curriculum, classroom management, and building management.…

The National Bureau of Asian Research

Science.gov Websites

security concerns, starting with overhauling CFIUS [Committee on Foreign Investment in the United States for Innovation, Trade, and StrategyJohn M. Shalikashvili Chair in National Security StudiesKenneth B ForumInnovative AsiaIndia's IP and Innovation PolicyThe Globalization of China's Life Science SectorAll IP

Analysis of intra-country virtual water trade strategy to alleviate water scarcity in Iran

NASA Astrophysics Data System (ADS)

Faramarzi, M.; Yang, H.; Mousavi, J.; Schulin, R.; Binder, C. R.; Abbaspour, K. C.

2010-08-01

Increasing water scarcity has posed a major constraint to sustain food production in many parts of the world. To study the situation at the regional level, we took Iran as an example and analyzed how an intra-country "virtual water trade strategy" (VWTS) may help improve cereal production as well as alleviate the water scarcity problem. This strategy calls, in part, for the adjustment of the structure of cropping pattern (ASCP) and interregional food trade where crop yield and crop water productivity as well as local economic and social conditions are taken into account. We constructed a systematic framework to assess ASCP at the provincial level under various driving forces and constraints. A mixed-integer, multi-objective, linear optimization model was developed and solved by linear programming. Data from 1990-2004 were used to account for yearly fluctuations of water availability and food production. Five scenarios were designed aimed at maximizing the national cereal production while meeting certain levels of wheat self-sufficiency under various water and land constraints in individual provinces. The results show that under the baseline scenario, which assumes a continuation of the existing water use and food policy at the national level, some ASCP scenarios could produce more wheat with less water. Based on different scenarios in ASCP, we calculated that 31% to 100% of the total wheat shortage in the deficit provinces could be supplied by the wheat surplus provinces. As a result, wheat deficit provinces would receive 3.5 billion m3 to 5.5 billion m3 of virtual water by importing wheat from surplus provinces.

Analysis of intra-country virtual water trade strategy to alleviate water scarcity in Iran

NASA Astrophysics Data System (ADS)

Faramarzi, M.; Yang, H.; Mousavi, J.; Schulin, R.; Binder, C. R.; Abbaspour, K. C.

2010-04-01

Increasing water scarcity has posed a major constraint to sustain food production in many parts of the world. To study the situation at the regional level, we took Iran as an example and analyzed how an intra-country "virtual water trade strategy" (VWTS) may help improve cereal production as well as alleviate the water scarcity problem. This strategy calls, in part, for the adjustment of the structure of cropping pattern (ASCP) and interregional food trade where crop yield and crop water productivity as well as local economic and social conditions are taken into account. We constructed a systematic framework to assess ASCP at the provincial level under various driving forces and constraints. A mixed-integer, multi-objective, linear optimization model was developed and solved by linear programming. Data from 1990-2004 were used to account for yearly fluctuations of water availability and food production. Five scenarios were designed aimed at maximizing the national cereal production while meeting certain levels of wheat self-sufficiency under various water and land constraints in individual provinces. The results show that under the baseline scenario, which assumes a continuation of the existing water use and food policy at the national level, some ASCP scenarios could produce more wheat with less water. Based on different scenarios in ASCP, we calculated that 31% to 100% of the total wheat shortage in the deficit provinces could be supplied by the wheat surplus provinces. As a result, wheat deficit provinces would receive 3.5 billion m3 to 5.5 billion m3 of virtual water by importing wheat from surplus provinces.

An analysis of occupational homicides involving workers 19 years old and younger.

PubMed

Janicak, C A

1999-12-01

Studies indicate that persons employed in various retail occupations such as convenience stores and restaurants experience an increased risk for being a victim of an occupational homicide. A large proportion of workers aged 19 and under are employed in these types of occupations. The purpose of this study was to determine if the workers from this age group employed in retail trades have a significantly greater risk for being a victim of a homicide. Data from the Bureau of Labor Statistics' Census of Fatal Occupational Injuries were analyzed in this study. The cases included in this study were victims of an occupational homicide that occurred during the period of 1992 to 1996. Proportionate mortality ratios were used to identify the industries in which workers aged 19 and under were experiencing significantly higher proportion of fatalities. Relative risks were calculated to determine if, based on the number of person-years of exposure, workers aged 19 and under in retail trades were experiencing a significantly greater relative risk for being a victim of an occupational homicide. Results indicate that workers aged 19 and under experience a significantly greater proportion of fatalities due to violence in the retail trade. Workers 19 years and under employed in retail trade occupations do experience a significantly greater proportion of fatalities than their counterparts in other industries. Prevention strategies presented include providing employee training and implementing various security measures.

Capacities of quantum amplifier channels

NASA Astrophysics Data System (ADS)

Qi, Haoyu; Wilde, Mark M.

2017-01-01

Quantum amplifier channels are at the core of several physical processes. Not only do they model the optical process of spontaneous parametric down-conversion, but the transformation corresponding to an amplifier channel also describes the physics of the dynamical Casimir effect in superconducting circuits, the Unruh effect, and Hawking radiation. Here we study the communication capabilities of quantum amplifier channels. Invoking a recently established minimum output-entropy theorem for single-mode phase-insensitive Gaussian channels, we determine capacities of quantum-limited amplifier channels in three different scenarios. First, we establish the capacities of quantum-limited amplifier channels for one of the most general communication tasks, characterized by the trade-off between classical communication, quantum communication, and entanglement generation or consumption. Second, we establish capacities of quantum-limited amplifier channels for the trade-off between public classical communication, private classical communication, and secret key generation. Third, we determine the capacity region for a broadcast channel induced by the quantum-limited amplifier channel, and we also show that a fully quantum strategy outperforms those achieved by classical coherent-detection strategies. In all three scenarios, we find that the capacities significantly outperform communication rates achieved with a naive time-sharing strategy.

Binary Hypothesis Testing With Byzantine Sensors: Fundamental Tradeoff Between Security and Efficiency

NASA Astrophysics Data System (ADS)

Ren, Xiaoqiang; Yan, Jiaqi; Mo, Yilin

2018-03-01

This paper studies binary hypothesis testing based on measurements from a set of sensors, a subset of which can be compromised by an attacker. The measurements from a compromised sensor can be manipulated arbitrarily by the adversary. The asymptotic exponential rate, with which the probability of error goes to zero, is adopted to indicate the detection performance of a detector. In practice, we expect the attack on sensors to be sporadic, and therefore the system may operate with all the sensors being benign for extended period of time. This motivates us to consider the trade-off between the detection performance of a detector, i.e., the probability of error, when the attacker is absent (defined as efficiency) and the worst-case detection performance when the attacker is present (defined as security). We first provide the fundamental limits of this trade-off, and then propose a detection strategy that achieves these limits. We then consider a special case, where there is no trade-off between security and efficiency. In other words, our detection strategy can achieve the maximal efficiency and the maximal security simultaneously. Two extensions of the secure hypothesis testing problem are also studied and fundamental limits and achievability results are provided: 1) a subset of sensors, namely "secure" sensors, are assumed to be equipped with better security countermeasures and hence are guaranteed to be benign, 2) detection performance with unknown number of compromised sensors. Numerical examples are given to illustrate the main results.

Simulated effect of pig-population density on epidemic size and choice of control strategy for classical swine fever epidemics in The Netherlands.

PubMed

Mangen, M-J J; Nielen, M; Burrell, A M

2002-12-18

We examined the importance of pig-population density in the area of an outbreak of classical swine fever (CSF) for the spread of the infection and the choice of control measures. A spatial, stochastic, dynamic epidemiological simulation model linked to a sector-level market-and-trade model for The Netherlands were used. Outbreaks in sparsely and densely populated areas were compared under four different control strategies and with two alternative trade assumptions. The obligatory control strategy required by current EU legislation was predicted to be enough to eradicate an epidemic starting in an area with sparse pig population. By contrast, additional control measures would be necessary if the outbreak began in an area with high pig density. The economic consequences of using preventive slaughter rather than emergency vaccination as an additional control measure depended strongly on the reactions of trading partners. Reducing the number of animal movements significantly reduced the size and length of epidemics in areas with high pig density. The phenomenon of carrier piglets was included in the model with realistic probabilities of infection by this route, but it made a negligible contribution to the spread of the infection.

Transient dynamics in trial-offer markets with social influence: Trade-offs between appeal and quality

PubMed Central

Altszyler, Edgar; Berbeglia, Franco; Van Hentenryck, Pascal

2017-01-01

We study a trial-offer market where consumers may purchase one of two competing products. Consumer preferences are affected by the products quality, their appeal, and their popularity. While the asymptotic convergence or stationary states of these, and related dynamical systems, has been vastly studied, the literature regarding the transitory dynamics remains surprisingly sparse. To fill this gap, we derive a system of Ordinary Differential Equations, which is solved exactly to gain insight into the roles played by product qualities and appeals in the market behavior. We observe a logarithmic tradeoff between quality and appeal for medium and long-term marketing strategies: The expected market shares remain constant if a decrease in quality is followed by an exponential increase in the product appeal. However, for short time horizons, the trade-off is linear. Finally, we study the variability of the dynamics through Monte Carlo simulations and discover that low appeals may result in high levels of variability. The model results suggest effective marketing strategies for short and long time horizons and emphasize the significance of advertising early in the market life to increase sales and predictability. PMID:28746334

[Women, health, and labor in Brazil: challenges for new action].

PubMed

Aquino, E M; Menezes, G M; Marinho, L F

1995-01-01

Despite the remarkable rise in women's participation in the labor market in Brazil, its consequences on health are still virtually unknown. This study aims to identify theoretical and methodological problems in the relationship between labor and women's health from a gender perspective. Characteristics of women's occupational placement are described and analyzed as resulting from their role in social reproduction. The study examines the development of several conciliatory strategies between paid work and housework which are discussed as potential determinants of health problems and support the need for a critical reappraisal of theoretical and methodological strategies to reach a better understanding of the complexity and specificities of women's living and working conditions. The author also stresses the role of women's recent participation in the trade union movements in defense of health, body rights, and women's issues in the workplace, as well as the need for a new framework embodied in the women's social movement. The study thus points to the challenge to produce knowledge on this subject in order to unveil the uniqueness of the national scenario marked by unemployment, informal jobs, low salaries, weak trade unions and other civil organizations, and traditional domestic and marriage relationships.

Transient dynamics in trial-offer markets with social influence: Trade-offs between appeal and quality.

PubMed

Altszyler, Edgar; Berbeglia, Franco; Berbeglia, Gerardo; Van Hentenryck, Pascal

2017-01-01

We study a trial-offer market where consumers may purchase one of two competing products. Consumer preferences are affected by the products quality, their appeal, and their popularity. While the asymptotic convergence or stationary states of these, and related dynamical systems, has been vastly studied, the literature regarding the transitory dynamics remains surprisingly sparse. To fill this gap, we derive a system of Ordinary Differential Equations, which is solved exactly to gain insight into the roles played by product qualities and appeals in the market behavior. We observe a logarithmic tradeoff between quality and appeal for medium and long-term marketing strategies: The expected market shares remain constant if a decrease in quality is followed by an exponential increase in the product appeal. However, for short time horizons, the trade-off is linear. Finally, we study the variability of the dynamics through Monte Carlo simulations and discover that low appeals may result in high levels of variability. The model results suggest effective marketing strategies for short and long time horizons and emphasize the significance of advertising early in the market life to increase sales and predictability.

75 FR 55840 - Self-Regulatory Organizations; NYSE Arca, Inc.; Order Granting Approval of a Proposed Rule Change...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-14

... Listing and Trading of Shares of the PIMCO Build America Bond Strategy Fund September 7, 2010. I..., which governs the listing and trading of Managed Fund Shares. The Shares will be offered by the Trust.\\4...% in the case of Recovery Zone Economic Development Bonds) of the interest paid. The federal interest...

National Geothermal Association Trade Mission to Central America

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

Not Available

1992-10-01

The United States (US) geothermal industry, the world's most technically proficient, has been unable to achieve penetration into the markets of the developing nations. This report details the findings of an industry Trade Mission to Central America, tasked with determining the reasons for this shortfall and with developing a US industry geothermal export strategy designed to achieve immediate and long-term export benefits.

78 FR 9938 - U.S.-Korea Free Trade Agreement: Effects on U.S. Small and Medium-Sized Enterprises; Institution...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-12

... Trade Agreement on U.S. small and medium-sized enterprises (SMEs) since entry into force of the... effects of the agreement on the production, distribution, and export strategy of U.S. SMEs, as identified by those SMEs, and describing how U.S. SMEs have benefited from specific provisions of the agreement...

Expanding Options. A Model to Attract Secondary Students into Nontraditional Vocational Programs. For Emphasis in: Building Trades, Electronics, Health Services, Machine Shop, Welding.

ERIC Educational Resources Information Center

Good, James D.; DeVore, Mary Ann

This model has been designed for use by Missouri secondary schools in attracting females and males into nontraditional occupational programs. The research-based strategies are intended for implementation in the following areas: attracting females into building trades, electronics, machine shop, and welding; and males into secondary health…

Instructional Design, Active Learning, and Student Performance: Using a Trading Room to Teach Strategy

ERIC Educational Resources Information Center

Stewart, Alice C.; Houghton, Susan M.; Rogers, Patrick R.

2012-01-01

This research used a quasi-experimental design with two conditions to test the impact of active learning in the context of integrated instructional design. The control condition was a traditional approach to teaching an undergraduate strategy capstone class. The intervention condition was an undergraduate strategy capstone class that was designed…

Key issues in the design of NO{sub x} emission trading programs to reduce ground-level ozone. Final report

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

Nichols, A.; Harrison, D.

1994-07-01

This report is the first product of a study being conducted by National Economic Research Associates for the Electric Power Research Institute to evaluate various market-based alternatives for managing emissions of nitrogen oxides (NO{sub x}) as part of strategies to achieve the ambient ozone standard. The report focuses on choices in the design of relatively broad, ambitious emission trading programs, rather than on more modest programs designed to generate offsets within a regulatory framework that continues to rely primarily on traditional emission standards and nontransferable permits. After a brief introductory chapter, Chapter 2 reviews both the conceptual underpinnings of emissionmore » trading and prior experience. This review suggests the need for clear initial allocations-generally based on emission caps-to simplify trading while assuring the achievement of emission-reduction goals. Chapter 3 lays out the basic choices required in establishing an emission trading program. For concreteness, the basic design is discussed in terms of trading among utilities and other large stationary sources of NO{sub x}, generally the most promising candidates for trading. Chapter 4 discusses various ways in which a basic trading program could be extended to other source categories and to volatile organic compounds (VOCs), the other major precursor of ozone. Chapter 5 analyzes various ways in which trading programs can be refined to focus control efforts on those times and at those locations where ozone problems are most severe. Although highly refined targeting programs are unlikely to be worth the effort, modest differentials can be implemented by making the number of allowances required for each ton of emissions vary with the time and location of emissions. Chapter 6 reviews various alternatives for making the initial allocation of emission allowances among sources in the trading program, breaking the process into two components, an emission rate and an activity level.« less

Characterizing copper flows in international trade of China, 1975-2015.

PubMed

Zhang, Ling; Chen, Tianming; Yang, Jiameng; Cai, Zhijian; Sheng, Hu; Yuan, Zengwei; Wu, Huijun

2017-12-01

Since the economic reform, China has actively participated in the global market with rapid industrialization and gradually dominated the utilization and consumption of some critical materials, one of which is copper. China has reigned the global anthropogenic cycle of copper since 2004. We explore copper flows along with the international trade of China during 1975-2015, through life cycle lens, from ore to final products. Our main finding is that China has become more active in the copper-related trade, indicated by its great increase in trade volume and the number of trade partners. The physical volume of copper flows through trade increased over 119 times between 1975 and 2015, mainly because of more imported raw materials of copper and exported copper products. Generally, China is a net importer of copper, with increasing import dependence through the study period, whereas the degree of dependence slightly decreased from 2010 to 2015. The indicator of Export Support Rate took a decreasing percentage, which has fallen about 35% since 2010. It suggests China's changing position in the global resource and manufacturing market. In terms of trade price of different copper products, the price of imported copper concentrate was noticeably higher than that of exported one, revealing the poor copper resource endowment of China; while the different trend of copper semis in recent years signifies that China is in urgent need to improve its capability of producing high value-added semis. From international trade perspective, the copper resource of China presented stable supply as well as demand. The One Belt One Road strategy proposed by the state will further expand both the resource and market of copper. Copyright © 2017 Elsevier B.V. All rights reserved.

Virtual water flows in the international trade of agricultural products of China.

PubMed

Zhang, Yu; Zhang, Jinhe; Tang, Guorong; Chen, Min; Wang, Lachun

2016-07-01

With the rapid development of the economy and population, water scarcity and poor water quality caused by water pollution have become increasingly severe in China. Virtual water trade is a useful tool to alleviate water shortage. This paper focuses on a comprehensive study of China's international virtual water flows from agricultural products trade and completes a diachronic analysis from 2001 to 2013. The results show that China was in trade surplus in relation to the virtual water trade of agricultural products. The exported virtual water amounted to 29.94billionm(3)/yr. while 155.55billionm(3)/yr. was embedded in imported products. The trend that China exported virtual water per year was on the decline while the imported was on a rising trend. Virtual water trade of China was highly concentrated. Not all of the exported products had comparative advantages in virtual water content. Imported products were excessively concentrated on water intensive agricultural products such as soya beans, cotton, and palm oil. The exported virtual water mainly flowed to the Republic of Korea, Hong Kong of China and Japan, while the imported mainly flowed from the United States of America, Brazil and Argentina. From the ethical point of view, the trade partners were classified into four types in terms of "net import" and "water abundance": mutual benefit countries, such as Australia and Canada; unilateral benefit countries, such as Mongolia and Norway; supported countries, such as Egypt and Singapore; and double pressure countries, such as India and Pakistan. Virtual water strategy refers to water resources, agricultural products and human beings. The findings are beneficial for innovating water resources management system, adjusting trade structure, ensuring food security in China, and promoting the construction of national ecological security system. Copyright © 2016 Elsevier B.V. All rights reserved.

WTO and Lifelong Education Strategies for Teachers

ERIC Educational Resources Information Center

Wang, Zhi-guo; Zheng, Yu

2006-01-01

After China's entry into the World Trade Organization (WTO), teachers have been confronted with many opportunities and challenges. Lifelong education strategies are problems we should take into account carefully. This article expounds the objective demands, ideas, content, measures and functions of lifelong education.

Adaptive trade-offs in juvenile salmonid metabolism associated with habitat partitioning between coho salmon and steelhead trout in coastal streams.

PubMed

Van Leeuwen, Travis E; Rosenfeld, Jordan S; Richards, Jeffrey G

2011-09-01

1. Adaptive trade-offs are fundamental to the evolution of diversity and the coexistence of similar taxa and occur when complimentary combinations of traits maximize efficiency of resource exploitation or survival at different points on environmental gradients. 2. Standard metabolic rate (SMR) is a key physiological trait that reflects adaptations to baseline metabolic performance, whereas active metabolism reflects adaptations to variable metabolic output associated with performance related to foraging, predator avoidance, aggressive interactions or migratory movements. Benefits of high SMR and active metabolism may change along a resource (productivity) gradient, indicating that a trade-off exists among active metabolism, resting metabolism and energy intake. 3. We measured and compared SMR, maximal metabolic rate (MMR), aerobic scope (AS), swim performance (UCrit) and growth of juvenile hatchery and wild steelhead and coho salmon held on high- and low-food rations in order to better understand the potential significance of variation in SMR to growth, differentiation between species, and patterns of habitat use along a productivity gradient. 4. We found that differences in SMR, MMR, AS, swim performance and growth rate between steelhead trout and coho salmon were reduced in hatchery-reared fish compared with wild fish. Wild steelhead had a higher MMR, AS, swim performance and growth rate than wild coho, but adaptations between species do not appear to involve differences in SMR or to trade-off increased growth rate against lower swim performance, as commonly observed for high-growth strains. Instead, we hypothesize that wild steelhead may be trading off higher growth rate for lower food consumption efficiency, similar to strategies adopted by anadromous vs. resident brook trout and Atlantic salmon vs. brook trout. This highlights potential differences in food consumption and digestion strategies as cryptic adaptations ecologically differentiating salmonid species. 5. We hypothesize that divergent digestive strategies, which are common and well documented among terrestrial vertebrates, may be an important but overlooked aspect of adaptive strategies of juvenile salmonids, and fish in general. © 2011 The Authors. Journal of Animal Ecology © 2011 British Ecological Society.

Micro and macro benefits of random investments in financial markets

NASA Astrophysics Data System (ADS)

Biondo, A. E.; Pluchino, A.; Rapisarda, A.

2014-10-01

In this paper, making use of recent statistical physics techniques and models, we address the specific role of randomness in financial markets, both at the micro and the macro level. In particular, we review some recent results obtained about the effectiveness of random strategies of investment, compared with some of the most used trading strategies for forecasting the behaviour of real financial indexes. We also push forward our analysis by means of a self-organised criticality model, able to simulate financial avalanches in trading communities with different network topologies, where a Pareto-like power law behaviour of wealth spontaneously emerges. In this context, we present new findings and suggestions for policies based on the effects that random strategies can have in terms of reduction of dangerous financial extreme events, i.e. bubbles and crashes.

Trade-off between early emergence and herbivore susceptibility mediates exotic success in an experimental California plant community.

PubMed

Waterton, Joseph; Cleland, Elsa E

2016-12-01

Ecological trade-offs are fundamental to theory in community ecology; critical for understanding species coexistence in diverse plant communities, as well as the evolution of diverse life-history strategies. Invasions by exotic species can provide insights into the importance of trade-offs in community assembly, because the ecological strategies of invading species often differ from those present in the native species pool. Exotic annual species have invaded many Mediterranean-climate areas around the globe, and often germinate and emerge earlier in the growing season than native species. Early-season growth can enable exotic annual species to preempt space and resources, competitively suppressing later-emerging native species; however, early-emerging individuals may also be more apparent to herbivores. This suggests a potential trade-off between seasonal phenology and susceptibility to herbivory. To evaluate this hypothesis, we monitored the emergence and growth of 12 focal species (six each native and exotic) in monoculture and polyculture, while experimentally excluding generalist herbivores both early and later in the growing season. Consistent with past studies, the exotic species emerged earlier than native species. Regardless of species origin, earlier-emerging species achieved greater biomass by the end of the experiment, but were more negatively impacted by herbivory, particularly in the early part of the growing season. This greater impact of early-season herbivory on early-active species led to a reduction in the competitive advantage of exotic species growing in polyculture, and improved the performance of later-emerging natives. Such a trade-off between early growth and susceptibility to herbivores could be an important force in community assembly in seasonal herbaceous-dominated ecosystems. These results also show how herbivore exclusion favors early-active exotic species in this system, with important implications for management in many areas invaded by early-active exotic species.

Strategies for Accommodating Extension Clients Who Face Language, Vision, or Hearing Challenges

ERIC Educational Resources Information Center

Angima, Sam; Etuk, Lena; Maddy, Deborah

2016-01-01

Extension services nationwide seek to equalize access to university resources for all learners. In this article, we focus on accommodation as a tool of our trade. We discuss findings and implications from a study that documented approaches used by one state's Extension professionals to accommodate clients who face language, vision, or hearing…

Recent evolution of China's virtual water trade: analysis of selected crops and considerations for policy

NASA Astrophysics Data System (ADS)

Shi, J.; Liu, J.; Pinter, L.

2013-09-01

China has dramatically increased its virtual water import unconsciously for recent years. Many studies have focused on the quantity of traded virtual water but very few go into analysing geographic distribution and the properties of China's virtual water trade network. This paper provides a calculation and analysis of the crop-related virtual water trade network of China based on 27 major primary crops between 1986 and 2009. The results show that China is a net importer of virtual water from water-abundant areas of North and South America, and a net virtual water exporter to water-stressed areas of Asia, Africa, and Europe. Virtual water import is far larger than virtual water export and in both import and export a small number of trade partners control the supply chain. Grain crops are the major contributors to virtual water trade, and among grain crops soybeans, mostly imported from the US, Brazil and Argentina are the most significant. As crop yield and crop water productivity in North and South America are generally higher than those in Asia and Africa, the effect of China's crop-related virtual water trade positively contributes to optimizing crop water use efficiency at the global scale. In order to mitigate water scarcity and secure the food supply, virtual water should be actively incorporated into national water management strategies. From the national perspective, China should reduce the export and increase the import of water-intensive crops. But the sources of virtual water import need to be further diversified to reduce supply chain risks and increase resilience.

Assessing the impact of the Australia-United States Free Trade Agreement on Australian and global medicines policy

PubMed Central

Faunce, Thomas; Doran, Evan; Henry, David; Drahos, Peter; Searles, Andrew; Pekarsky, Brita; Neville, Warwick

2005-01-01

On 1 January 2005, a controversial trade agreement entered into force between Australia and the United States. Though heralded by the parties as facilitating the removal of barriers to free trade (in ways not achievable in multilateral fora), it also contained many trade-restricting intellectual property provisions and others uniquely related to altering pharmaceutical regulation and public health policy in Australia. The latter appear to have particularly focused on the world-respected process of federal government reimbursement after expert cost-effectiveness evaluation, popularly known as the Pharmaceutical Benefits Scheme ('PBS'). It remains uncertain what sort of impacts – if any – the Australia-United States Free Trade Agreement ('AUSFTA') will have on PBS processes such as reference pricing and their important role in facilitating equitable and affordable access to essential medicines. This is now the field of inquiry for a major three year Australian Research Council ('ARC')-funded study bringing together a team of senior researchers in regulatory theory from the Australian National University and pharmacoeconomics from the University of Newcastle. The project proposes to monitor, assess and analyse the real and potential impacts of the AUSFTA in this area, providing Australian policy-makers with continuing expertise and options. To the extent that the AUSFTA medicines provisions may represent an important precedent in a global strategy by industry on cost-effectiveness evaluation of pharmaceuticals, the study will also be of great interest to policy makers in other jurisdictions. PMID:16209703

Difference in C3-C4 metabolism underlies tradeoff between growth rate and biomass yield in Methylobacterium extorquens AM1.

PubMed

Fu, Yanfen; Beck, David A C; Lidstrom, Mary E

2016-07-19

Two variants of Methylobacterium extorquens AM1 demonstrated a trade-off between growth rate and biomass yield. In addition, growth rate and biomass yield were also affected by supplementation of growth medium with different amounts of cobalt. The metabolism changes relating to these growth phenomena as well as the trade-off were investigated in this study. (13)C metabolic flux analysis was used to generate a detailed central carbon metabolic flux map with both absolute and normalized flux values. The major differences between the two variants occurred at the formate node as well as within C3-C4 inter-conversion pathways. Higher relative fluxes through formyltetrahydrofolate ligase, phosphoenolpyruvate carboxylase, and malic enzyme led to higher biomass yield, while higher relative fluxes through pyruvate kinase and pyruvate dehydrogenase led to higher growth rate. These results were then tested by phenotypic studies on three mutants (null pyk, null pck mutant and null dme mutant) in both variants, which agreed with the model prediction. In this study, (13)C metabolic flux analysis for two strain variants of M. extorquens AM1 successfully identified metabolic pathways contributing to the trade-off between cell growth and biomass yield. Phenotypic analysis of mutants deficient in corresponding genes supported the conclusion that C3-C4 inter-conversion strategies were the major response to the trade-off.

Mission Design and Optimal Asteroid Deflection for Planetary Defense

NASA Technical Reports Server (NTRS)

Sarli, Bruno V.; Knittel, Jeremy M.; Englander, Jacob A.; Barbee, Brent W.

2017-01-01

Planetary defense is a topic of increasing interest for many reasons, which has been mentioned in "Vision and Voyages for Planetary Science in the Decade 2013-2022''. However, perhaps one of the most significant rationales for asteroid studies is the number of close approaches that have been documented recently. A space mission with a planetary defense objective aims to deflect the threatening body as far as possible from Earth. The design of a mission that optimally deflects an asteroid has different challenges: speed, precision, and system trade-off. This work addresses such issues and develops a fast transcription of the problem that can be implemented into an optimization tool, which allows for a broader trade study of different mission concepts with a medium fidelity. Such work is suitable for a mission?s preliminary study. It is shown, using the fictitious asteroid impact scenario 2017 PDC, that the complete tool is able to account for the orbit sensitivity to small perturbations and quickly optimize a deflection trajectory. The speed in which the tool operates allows for a trade study between the available hardware. As a result, key deflection dates and mission strategies are identified for the 2017 PDC.

Mission Design and Optimal Asteroid Deflection for Planetary Defense

NASA Technical Reports Server (NTRS)

Sarli, Bruno V.; Knittel, Jeremy M.; Englander, Jacob A.; Barbee, Brent W.

2017-01-01

Planetary defense is a topic of increasing interest for many reasons, which has been mentioned in "Vision and Voyages for Planetary Science in the Decade 2013-2022". However, perhaps one of the most significant rationales for asteroid studies is the number of close approaches that have been documented recently. A space mission with a planetary defense objective aims to deflect the threatening body as far as possible from Earth. The design of a mission that optimally deflects an asteroid has different challenges: speed, precision, and system trade-off. This work addresses such issues and develops a fast transcription of the problem that can be implemented into an optimization tool, which allows for a broader trade study of different mission concepts with a medium fidelity. Such work is suitable for a mission's preliminary study. It is shown, using the fictitious asteroid impact scenario 2017 PDC, that the complete tool is able to account for the orbit sensitivity to small perturbations and quickly optimize a deflection trajectory. The speed in which the tool operates allows for a trade study between the available hardware. As a result, key deflection dates and mission strategies are identified for the 2017 PDC.

International trade in services: a growing trend among highly skilled migrants with special reference to Asia.

PubMed

Garnier, P

1996-01-01

"An essential component of trade in services is cross-border movements of service providers.... On the one hand, there are international movements of skilled transients who emigrate for individual reasons in a long term perspective. On the other hand, there are skilled temporary migrants who perform services abroad without the intention or right to settle or seek employment in the host country. This study aims to clarify these differences using the example provided by the Asian Pacific region. Moreover, this study shows that the dynamics of skilled international migration is largely determined by the circulatory movement of skills of international service providers and has emerged as an essential component of economic development strategy of the countries in the region." excerpt

Multi-objective optimisation of wastewater treatment plant control to reduce greenhouse gas emissions.

PubMed

Sweetapple, Christine; Fu, Guangtao; Butler, David

2014-05-15

This study investigates the potential of control strategy optimisation for the reduction of operational greenhouse gas emissions from wastewater treatment in a cost-effective manner, and demonstrates that significant improvements can be realised. A multi-objective evolutionary algorithm, NSGA-II, is used to derive sets of Pareto optimal operational and control parameter values for an activated sludge wastewater treatment plant, with objectives including minimisation of greenhouse gas emissions, operational costs and effluent pollutant concentrations, subject to legislative compliance. Different problem formulations are explored, to identify the most effective approach to emissions reduction, and the sets of optimal solutions enable identification of trade-offs between conflicting objectives. It is found that multi-objective optimisation can facilitate a significant reduction in greenhouse gas emissions without the need for plant redesign or modification of the control strategy layout, but there are trade-offs to consider: most importantly, if operational costs are not to be increased, reduction of greenhouse gas emissions is likely to incur an increase in effluent ammonia and total nitrogen concentrations. Design of control strategies for a high effluent quality and low costs alone is likely to result in an inadvertent increase in greenhouse gas emissions, so it is of key importance that effects on emissions are considered in control strategy development and optimisation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Measurement strategy for rectangular electrical capacitance tomography sensor

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

Ye, Jiamin; Ge, Ruihuan; Qiu, Guizhi

2014-04-11

To investigate the influence of the measurement strategy for the rectangular electrical capacitance tomography (ECT) sensor, a Finite Element Method (FEM) is utilized to create the model for simulation. The simulation was carried out using COMSOL Multiphysics(trade mark, serif) and Matlab(trade mark, serif). The length-width ratio of the rectangular sensing area is 5. Twelve electrodes are evenly arranged surrounding the pipe. The covering ratio of the electrodes is 90%. The capacitances between different electrode pairs are calculated for a bar distribution. The air of the relative permittivity 1.0 and the material of the permittivity 3.0 are used for the calibration.more » The relative permittivity of the second phase is 3.0. The noise free and noise data are used for the image reconstruction using the Linear Back Projection (LBP). The measurement strategies with 1-, 2- and 4- electrode excitation are compared using the correlation coefficient. Preliminary results show that the measurement strategy with 2-electrode excitation outperforms other measurement strategies with 1- or 4-electrode excitation.« less

77 FR 8809 - United States Travel and Tourism Advisory Board; Teleconference Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-15

... DEPARTMENT OF COMMERCE International Trade Administration United States Travel and Tourism... Commerce. ACTION: Notice of an open teleconference meeting. SUMMARY: The United States Travel and Tourism... National Travel and Tourism Strategy (Strategy). The Executive Order was issued by President Barack Obama...

Spatial and Functional Organization of Pig Trade in Different European Production Systems: Implications for Disease Prevention and Control.

PubMed

Relun, Anne; Grosbois, Vladimir; Sánchez-Vizcaíno, José Manuel; Alexandrov, Tsviatko; Feliziani, Francesco; Waret-Szkuta, Agnès; Molia, Sophie; Etter, Eric Marcel Charles; Martínez-López, Beatriz

2016-01-01

Understanding the complexity of live pig trade organization is a key factor to predict and control major infectious diseases, such as classical swine fever (CSF) or African swine fever (ASF). Whereas the organization of pig trade has been described in several European countries with indoor commercial production systems, little information is available on this organization in other systems, such as outdoor or small-scale systems. The objective of this study was to describe and compare the spatial and functional organization of live pig trade in different European countries and different production systems. Data on premise characteristics and pig movements between premises were collected during 2011 from Bulgaria, France, Italy, and Spain, which swine industry is representative of most of the production systems in Europe (i.e., commercial vs. small-scale and outdoor vs. indoor). Trade communities were identified in each country using the Walktrap algorithm. Several descriptive and network metrics were generated at country and community levels. Pig trade organization showed heterogeneous spatial and functional organization. Trade communities mostly composed of indoor commercial premises were identified in western France, northern Italy, northern Spain, and north-western Bulgaria. They covered large distances, overlapped in space, demonstrated both scale-free and small-world properties, with a role of trade operators and multipliers as key premises. Trade communities involving outdoor commercial premises were identified in western Spain, south-western and central France. They were more spatially clustered, demonstrated scale-free properties, with multipliers as key premises. Small-scale communities involved the majority of premises in Bulgaria and in central and Southern Italy. They were spatially clustered and had scale-free properties, with key premises usually being commercial production premises. These results indicate that a disease might spread very differently according to the production system and that key premises could be targeted to more cost-effectively control diseases. This study provides useful epidemiological information and parameters that could be used to design risk-based surveillance strategies or to more accurately model the risk of introduction or spread of devastating swine diseases, such as ASF, CSF, or foot-and-mouth disease.

Spatial and Functional Organization of Pig Trade in Different European Production Systems: Implications for Disease Prevention and Control

PubMed Central

Relun, Anne; Grosbois, Vladimir; Sánchez-Vizcaíno, José Manuel; Alexandrov, Tsviatko; Feliziani, Francesco; Waret-Szkuta, Agnès; Molia, Sophie; Etter, Eric Marcel Charles; Martínez-López, Beatriz

2016-01-01

Understanding the complexity of live pig trade organization is a key factor to predict and control major infectious diseases, such as classical swine fever (CSF) or African swine fever (ASF). Whereas the organization of pig trade has been described in several European countries with indoor commercial production systems, little information is available on this organization in other systems, such as outdoor or small-scale systems. The objective of this study was to describe and compare the spatial and functional organization of live pig trade in different European countries and different production systems. Data on premise characteristics and pig movements between premises were collected during 2011 from Bulgaria, France, Italy, and Spain, which swine industry is representative of most of the production systems in Europe (i.e., commercial vs. small-scale and outdoor vs. indoor). Trade communities were identified in each country using the Walktrap algorithm. Several descriptive and network metrics were generated at country and community levels. Pig trade organization showed heterogeneous spatial and functional organization. Trade communities mostly composed of indoor commercial premises were identified in western France, northern Italy, northern Spain, and north-western Bulgaria. They covered large distances, overlapped in space, demonstrated both scale-free and small-world properties, with a role of trade operators and multipliers as key premises. Trade communities involving outdoor commercial premises were identified in western Spain, south-western and central France. They were more spatially clustered, demonstrated scale-free properties, with multipliers as key premises. Small-scale communities involved the majority of premises in Bulgaria and in central and Southern Italy. They were spatially clustered and had scale-free properties, with key premises usually being commercial production premises. These results indicate that a disease might spread very differently according to the production system and that key premises could be targeted to more cost-effectively control diseases. This study provides useful epidemiological information and parameters that could be used to design risk-based surveillance strategies or to more accurately model the risk of introduction or spread of devastating swine diseases, such as ASF, CSF, or foot-and-mouth disease. PMID:26870738

Divergence in plant and microbial allocation strategies explains continental patterns in microbial allocation and biogeochemical fluxes.

PubMed

Averill, Colin

2014-10-01

Allocation trade-offs shape ecological and biogeochemical phenomena at local to global scale. Plant allocation strategies drive major changes in ecosystem carbon cycling. Microbial allocation to enzymes that decompose carbon vs. organic nutrients may similarly affect ecosystem carbon cycling. Current solutions to this allocation problem prioritise stoichiometric tradeoffs implemented in plant ecology. These solutions may not maximise microbial growth and fitness under all conditions, because organic nutrients are also a significant carbon resource for microbes. I created multiple allocation frameworks and simulated microbial growth using a microbial explicit biogeochemical model. I demonstrate that prioritising stoichiometric trade-offs does not optimise microbial allocation, while exploiting organic nutrients as carbon resources does. Analysis of continental-scale enzyme data supports the allocation patterns predicted by this framework, and modelling suggests large deviations in soil C loss based on which strategy is implemented. Therefore, understanding microbial allocation strategies will likely improve our understanding of carbon cycling and climate. © 2014 John Wiley & Sons Ltd/CNRS.

FOREX Trades: Can the Takens Algorithm Help to Obtain Steady Profit at Investment Reallocations?

NASA Astrophysics Data System (ADS)

Petrov, V. Yu.; Tribelsky, M. I.

2015-12-01

We report our preliminary results of application of the Takens algorithm to build a FOREX trade strategy, resulting in a steady long-time gain for a trader. The actual historical rates for pair EUR vs. USD are used. The values of various parameters of the problem including the "stop loss" and "take profit" thresholds are optimized to provide the maximal gain during the training period. Then, these values are employed for trades. We have succeeded to get the steady gain, if the spread is neglected. It proves that the FOREX market is predictable.

Construction of multiple trade-offs to obtain arbitrary singularities of adaptive dynamics.

PubMed

Kisdi, Éva

2015-04-01

Evolutionary singularities are central to the adaptive dynamics of evolving traits. The evolutionary singularities are strongly affected by the shape of any trade-off functions a model assumes, yet the trade-off functions are often chosen in an ad hoc manner, which may unjustifiably constrain the evolutionary dynamics exhibited by the model. To avoid this problem, critical function analysis has been used to find a trade-off function that yields a certain evolutionary singularity such as an evolutionary branching point. Here I extend this method to multiple trade-offs parameterized with a scalar strategy. I show that the trade-off functions can be chosen such that an arbitrary point in the viability domain of the trait space is a singularity of an arbitrary type, provided (next to certain non-degeneracy conditions) that the model has at least two environmental feedback variables and at least as many trade-offs as feedback variables. The proof is constructive, i.e., it provides an algorithm to find trade-off functions that yield the desired singularity. I illustrate the construction of trade-offs with an example where the virulence of a pathogen evolves in a small ecosystem of a host, its pathogen, a predator that attacks the host and an alternative prey of the predator.

Stock Portfolio Structure of Individual Investors Infers Future Trading Behavior

PubMed Central

Bohlin, Ludvig; Rosvall, Martin

2014-01-01

Although the understanding of and motivation behind individual trading behavior is an important puzzle in finance, little is known about the connection between an investor's portfolio structure and her trading behavior in practice. In this paper, we investigate the relation between what stocks investors hold, and what stocks they buy, and show that investors with similar portfolio structures to a great extent trade in a similar way. With data from the central register of shareholdings in Sweden, we model the market in a similarity network, by considering investors as nodes, connected with links representing portfolio similarity. From the network, we find investor groups that not only identify different investment strategies, but also represent individual investors trading in a similar way. These findings suggest that the stock portfolios of investors hold meaningful information, which could be used to earn a better understanding of stock market dynamics. PMID:25068302

Intelligent data management for real-time spacecraft monitoring

NASA Technical Reports Server (NTRS)

Schwuttke, Ursula M.; Gasser, Les; Abramson, Bruce

1992-01-01

Real-time AI systems have begun to address the challenge of restructuring problem solving to meet real-time constraints by making key trade-offs that pursue less than optimal strategies with minimal impact on system goals. Several approaches for adapting to dynamic changes in system operating conditions are known. However, simultaneously adapting system decision criteria in a principled way has been difficult. Towards this end, a general technique for dynamically making such trade-offs using a combination of decision theory and domain knowledge has been developed. Multi-attribute utility theory (MAUT), a decision theoretic approach for making one-time decisions is discussed and dynamic trade-off evaluation is described as a knowledge-based extension of MAUT that is suitable for highly dynamic real-time environments, and provides an example of dynamic trade-off evaluation applied to a specific data management trade-off in a real-world spacecraft monitoring application.

Stock portfolio structure of individual investors infers future trading behavior.

PubMed

Bohlin, Ludvig; Rosvall, Martin

2014-01-01

Although the understanding of and motivation behind individual trading behavior is an important puzzle in finance, little is known about the connection between an investor's portfolio structure and her trading behavior in practice. In this paper, we investigate the relation between what stocks investors hold, and what stocks they buy, and show that investors with similar portfolio structures to a great extent trade in a similar way. With data from the central register of shareholdings in Sweden, we model the market in a similarity network, by considering investors as nodes, connected with links representing portfolio similarity. From the network, we find investor groups that not only identify different investment strategies, but also represent individual investors trading in a similar way. These findings suggest that the stock portfolios of investors hold meaningful information, which could be used to earn a better understanding of stock market dynamics.

National Geothermal Association Trade Mission to Central America

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

Not Available

1992-10-01

The United States (US) geothermal industry, the world`s most technically proficient, has been unable to achieve penetration into the markets of the developing nations. This report details the findings of an industry Trade Mission to Central America, tasked with determining the reasons for this shortfall and with developing a US industry geothermal export strategy designed to achieve immediate and long-term export benefits.

How Much is it Going to Cost Me to Complete a Collection of Football Trading Cards?

ERIC Educational Resources Information Center

Gerke, Oke

2013-01-01

Trading cards for various sports and a range of other subjects such as architecture, animals, hobbies, and war have been in existence since the late nineteenth century and still enjoy great popularity. Two of the most prominent examples are baseball cards in the U.S. and football cards in Europe. Three strategies for collecting European football…

The effects of processing non-timber forest products and trade partnerships on people's well-being and forest conservation in Amazonian societies.

PubMed

Morsello, Carla; Ruiz-Mallén, Isabel; Diaz, Maria Dolores Montoya; Reyes-García, Victoria

2012-01-01

This study evaluated whether processing non-timber forest products (NTFPs) and establishing trade partnerships between forest communities and companies enhance the outcomes of NTFP commercialization. In particular, we evaluated whether product processing, partnerships, or their combination was associated with a number of outcomes related to the well-being of forest inhabitants and forest conservation. We based our analyses on ethnographic and quantitative data (i.e., survey and systematic observations) gathered at seven communities from five societies of the Brazilian and Bolivian Amazon. Our results indicated that product processing and partnerships do not represent a silver bullet able to improve the results of NTFP commercialization in terms of well-being and conservation indicators. Compared with cases without interventions, households adopting partnerships but not product processing were most often associated with improved economic proxies of well-being (total income, NTFP income, food consumption and gender equality in income). In comparison, the combination of product processing and partnerships was associated with similar outcomes. Unexpectedly, product processing alone was associated with negative outcomes in the economic indicators of well-being. All of the investigated strategies were associated with less time spent in social and cultural activities. With respect to forest conservation, the strategies that included a partnership with or without processing produced similar results: while household deforestation tended to decrease, the hunting impact increased. Processing alone was also associated with higher levels of hunting, though it did not reduce deforestation. Our results indicate that establishing partnerships may enhance the outcomes of NTFP trade in terms of the financial outcomes of local communities, but practitioners need to use caution when adopting the processing strategy and they need to evaluate potential negative results for indicators of social and cultural activities. With respect to conservation, the three strategies are promising for reducing deforestation, but more pervasive impacts, such as hunting, might increase.

The Effects of Processing Non-Timber Forest Products and Trade Partnerships on People's Well-Being and Forest Conservation in Amazonian Societies

PubMed Central

Morsello, Carla; Ruiz-Mallén, Isabel; Diaz, Maria Dolores Montoya; Reyes-García, Victoria

2012-01-01

This study evaluated whether processing non-timber forest products (NTFPs) and establishing trade partnerships between forest communities and companies enhance the outcomes of NTFP commercialization. In particular, we evaluated whether product processing, partnerships, or their combination was associated with a number of outcomes related to the well-being of forest inhabitants and forest conservation. We based our analyses on ethnographic and quantitative data (i.e., survey and systematic observations) gathered at seven communities from five societies of the Brazilian and Bolivian Amazon. Our results indicated that product processing and partnerships do not represent a silver bullet able to improve the results of NTFP commercialization in terms of well-being and conservation indicators. Compared with cases without interventions, households adopting partnerships but not product processing were most often associated with improved economic proxies of well-being (total income, NTFP income, food consumption and gender equality in income). In comparison, the combination of product processing and partnerships was associated with similar outcomes. Unexpectedly, product processing alone was associated with negative outcomes in the economic indicators of well-being. All of the investigated strategies were associated with less time spent in social and cultural activities. With respect to forest conservation, the strategies that included a partnership with or without processing produced similar results: while household deforestation tended to decrease, the hunting impact increased. Processing alone was also associated with higher levels of hunting, though it did not reduce deforestation. Our results indicate that establishing partnerships may enhance the outcomes of NTFP trade in terms of the financial outcomes of local communities, but practitioners need to use caution when adopting the processing strategy and they need to evaluate potential negative results for indicators of social and cultural activities. With respect to conservation, the three strategies are promising for reducing deforestation, but more pervasive impacts, such as hunting, might increase. PMID:22912787

Memory effects in stock price dynamics: evidences of technical trading

PubMed Central

Garzarelli, Federico; Cristelli, Matthieu; Pompa, Gabriele; Zaccaria, Andrea; Pietronero, Luciano

2014-01-01

Technical trading represents a class of investment strategies for Financial Markets based on the analysis of trends and recurrent patterns in price time series. According standard economical theories these strategies should not be used because they cannot be profitable. On the contrary, it is well-known that technical traders exist and operate on different time scales. In this paper we investigate if technical trading produces detectable signals in price time series and if some kind of memory effects are introduced in the price dynamics. In particular, we focus on a specific figure called supports and resistances. We first develop a criterion to detect the potential values of supports and resistances. Then we show that memory effects in the price dynamics are associated to these selected values. In fact we show that prices more likely re-bounce than cross these values. Such an effect is a quantitative evidence of the so-called self-fulfilling prophecy, that is the self-reinforcement of agents' belief and sentiment about future stock prices' behavior. PMID:24671011

Memory effects in stock price dynamics: evidences of technical trading

NASA Astrophysics Data System (ADS)

Garzarelli, Federico; Cristelli, Matthieu; Pompa, Gabriele; Zaccaria, Andrea; Pietronero, Luciano

2014-03-01

Technical trading represents a class of investment strategies for Financial Markets based on the analysis of trends and recurrent patterns in price time series. According standard economical theories these strategies should not be used because they cannot be profitable. On the contrary, it is well-known that technical traders exist and operate on different time scales. In this paper we investigate if technical trading produces detectable signals in price time series and if some kind of memory effects are introduced in the price dynamics. In particular, we focus on a specific figure called supports and resistances. We first develop a criterion to detect the potential values of supports and resistances. Then we show that memory effects in the price dynamics are associated to these selected values. In fact we show that prices more likely re-bounce than cross these values. Such an effect is a quantitative evidence of the so-called self-fulfilling prophecy, that is the self-reinforcement of agents' belief and sentiment about future stock prices' behavior.

Influence of the large-small split effect on strategy choice in complex subtraction.

PubMed

Xiang, Yan Hui; Wu, Hao; Shang, Rui Hong; Chao, Xiaomei; Ren, Ting Ting; Zheng, Li Ling; Mo, Lei

2018-04-01

Two main theories have been used to explain the arithmetic split effect: decision-making process theory and strategy choice theory. Using the inequality paradigm, previous studies have confirmed that individuals tend to adopt a plausibility-checking strategy and a whole-calculation strategy to solve large and small split problems in complex addition arithmetic, respectively. This supports strategy choice theory, but it is unknown whether this theory also explains performance in solving different split problems in complex subtraction arithmetic. This study used small, intermediate and large split sizes, with each split condition being further divided into problems requiring and not requiring borrowing. The reaction times (RTs) for large and intermediate splits were significantly shorter than those for small splits, while accuracy was significantly higher for large and middle splits than for small splits, reflecting no speed-accuracy trade-off. Further, RTs and accuracy differed significantly between the borrow and no-borrow conditions only for small splits. This study indicates that strategy choice theory is suitable to explain the split effect in complex subtraction arithmetic. That is, individuals tend to choose the plausibility-checking strategy or the whole-calculation strategy according to the split size. © 2016 International Union of Psychological Science.

Waterpipe industry products and marketing strategies: analysis of an industry trade exhibition.

PubMed

Jawad, Mohammed; Nakkash, Rima T; Hawkins, Ben; Akl, Elie A

2015-12-01

Understanding product development and marketing strategies of transnational tobacco companies (TTCs) has been of vital importance in developing an effective tobacco control policy. However, comparatively little is known of the waterpipe tobacco industry, which TTCs have recently entered. This study aimed to gain an understanding of waterpipe tobacco products and marketing strategies by visiting a waterpipe trade exhibition. In April 2014, the first author attended an international waterpipe trade exhibition, recording descriptions of products and collecting all available marketing items. We described the purpose and function of all products, and performed a thematic analysis of messages in marketing material. We classified waterpipe products into four categories and noted product variation within categories. Electronic waterpipe products (which mimic electronic cigarettes) rarely appeared on waterpipe tobacco marketing material, but were displayed just as widely. Claims of reduced harm, safety and quality were paramount on marketing materials, regardless of whether they were promoting consumption products (tobacco, tobacco substitutes), electronic waterpipes or accessories. Waterpipe products are diverse in nature and are marketed as healthy and safe products. Furthermore, the development of electronic waterpipe products appears to be closely connected with the electronic cigarette industry, rather than the waterpipe tobacco manufacturers. Tobacco control policy must evolve to take account of the vast and expanding array of waterpipe products, and potentially also charcoal products developed for waterpipe smokers. We recommend that tobacco substitutes be classified as tobacco products. Continued surveillance of the waterpipe industry is warranted. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Exploiting water versus tolerating drought: water-use strategies of trees in a secondary successional tropical dry forest.

PubMed

Pineda-García, Fernando; Paz, Horacio; Meinzer, Frederick C; Angeles, Guillermo

2016-02-01

In seasonal plant communities where water availability changes dramatically both between and within seasons, understanding the mechanisms that enable plants to exploit water pulses and to survive drought periods is crucial. By measuring rates of physiological processes, we examined the trade-off between water exploitation and drought tolerance among seedlings of trees of a tropical dry forest, and identified biophysical traits most closely associated with plant water-use strategies. We also explored whether early and late secondary successional species occupy different portions of trade-off axes. As predicted, species that maintained carbon capture, hydraulic function and leaf area at higher plant water deficits during drought had low photosynthetic rates, xylem hydraulic conductivity and growth rate under non-limiting water supply. Drought tolerance was associated with more dense leaf, stem and root tissues, whereas rapid resource acquisition was associated with greater stem water storage, larger vessel diameter and larger leaf area per mass invested. We offer evidence that the water exploitation versus drought tolerance trade-off drives species differentiation in the ability of tropical dry forest trees to deal with alternating water-drought pulses. However, we detected no evidence of strong functional differentiation between early and late successional species along the proposed trade-off axes, suggesting that the environmental gradient of water availability across secondary successional habitats in the dry tropics does not filter out physiological strategies of water use among species, at least at the seedling stage. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Greenhouse Gas Mitigation Options in ISEEM Global Energy Model: 2010-2050 Scenario Analysis for Least-Cost Carbon Reduction in Iron and Steel Sector

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

Karali, Nihan; Xu, Tengfang; Sathaye, Jayant

The goal of the modeling work carried out in this project was to quantify long-term scenarios for the future emission reduction potentials in the iron and steel sector. The main focus of the project is to examine the impacts of carbon reduction options in the U.S. iron and steel sector under a set of selected scenarios. In order to advance the understanding of carbon emission reduction potential on the national and global scales, and to evaluate the regional impacts of potential U.S. mitigation strategies (e.g., commodity and carbon trading), we also included and examined the carbon reduction scenarios in China’smore » and India’s iron and steel sectors in this project. For this purpose, a new bottom-up energy modeling framework, the Industrial Sector Energy Efficiency Modeling (ISEEM), (Karali et al. 2012) was used to provide detailed annual projections starting from 2010 through 2050. We used the ISEEM modeling framework to carry out detailed analysis, on a country-by-country basis, for the U.S., China’s, and India’s iron and steel sectors. The ISEEM model applicable to iron and steel section, called ISEEM-IS, is developed to estimate and evaluate carbon emissions scenarios under several alternative mitigation options - including policies (e.g., carbon caps), commodity trading, and carbon trading. The projections will help us to better understand emission reduction potentials with technological and economic implications. The database for input of ISEEM-IS model consists of data and information compiled from various resources such as World Steel Association (WSA), the U.S. Geological Survey (USGS), China Steel Year Books, India Bureau of Mines (IBM), Energy Information Administration (EIA), and recent LBNL studies on bottom-up techno-economic analysis of energy efficiency measures in the iron and steel sector of the U.S., China, and India, including long-term steel production in China. In the ISEEM-IS model, production technology and manufacturing details are represented, in addition to the extensive data compiled from recent studies on bottom-up representation of efficiency measures for the sector. We also defined various mitigation scenarios including long-term production trends to project country-specific production, energy use, trading, carbon emissions, and costs of mitigation. Such analyses can provide useful information to assist policy-makers when considering and shaping future emissions mitigation strategies and policies. The technical objective is to analyze the costs of production and CO 2 emission reduction in the U.S, China, and India’s iron and steel sectors under different emission reduction scenarios, using the ISEEM-IS as a cost optimization model. The scenarios included in this project correspond to various CO 2 emission reduction targets for the iron and steel sector under different strategies such as simple CO 2 emission caps (e.g., specific reduction goals), emission reduction via commodity trading, and emission reduction via carbon trading.« less

Do not fear your opponent: suboptimal changes of a prevention strategy when facing stronger opponents.

PubMed

Slezak, Diego Fernandez; Sigman, Mariano

2012-08-01

The time spent making a decision and its quality define a widely studied trade-off. Some models suggest that the time spent is set to optimize reward, as verified empirically in simple-decision making experiments. However, in a more complex perspective compromising components of regulation focus, ambitions, fear, risk and social variables, adjustment of the speed-accuracy trade-off may not be optimal. Specifically, regulatory focus theory shows that people can be set in a promotion mode, where focus is on seeking to approach a desired state (to win), or in a prevention mode, focusing to avoid undesired states (not to lose). In promotion, people are eager to take risks increasing speed and decreasing accuracy. In prevention, strategic vigilance increases, decreasing speed and improving accuracy. When time and accuracy have to be compromised, one can ask which of these 2 strategies optimizes reward, leading to optimal performance. This is investigated here in a unique experimental environment. Decision making is studied in rapid-chess (180 s per game), in which the goal of a player is to mate the opponent in a finite amount of time or, alternatively, time-out of the opponent with sufficient material to mate. In different games, players face strong and weak opponents. It was observed that (a) players adopt a more conservative strategy when facing strong opponents, with slower and more accurate moves, and (b) this strategy is suboptimal: Players increase their winning likelihood against strong opponents using the policy they adopt when confronting opponents with similar strength. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

Difference in C3–C4 metabolism underlies tradeoff between growth rate and biomass yield in Methylobacterium extorquens AM1

DOE PAGES

Fu, Yanfen; Beck, David A. C.; Lidstrom, Mary E.

2016-07-19

In this study, two variants of Methylobacterium extorquens AM1 demonstrated a trade-off between growth rate and biomass yield. In addition, growth rate and biomass yield were also affected by supplementation of growth medium with different amounts of cobalt. The metabolism changes relating to these growth phenomena as well as the trade-off were investigated in this study. 13C metabolic flux analysis was used to generate a detailed central carbon metabolic flux map with both absolute and normalized flux values. As a result, the major differences between the two variants occurred at the formate node as well as within C3-C4 inter-conversion pathways.more » Higher relative fluxes through formyltetrahydrofolate ligase, phosphoenolpyruvate carboxylase, and malic enzyme led to higher biomass yield, while higher relative fluxes through pyruvate kinase and pyruvate dehydrogenase led to higher growth rate. These results were then tested by phenotypic studies on three mutants (null pyk, null pck mutant and null dme mutant) in both variants, which agreed with the model prediction. In this study, 13C metabolic flux analysis for two strain variants of M. extorquens AM1 successfully identified metabolic pathways contributing to the trade-off between cell growth and biomass yield. Phenotypic analysis of mutants deficient in corresponding genes supported the conclusion that C3-C4 inter-conversion strategies were the major response to the trade-off.« less

Difference in C3–C4 metabolism underlies tradeoff between growth rate and biomass yield in Methylobacterium extorquens AM1

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

Fu, Yanfen; Beck, David A. C.; Lidstrom, Mary E.

In this study, two variants of Methylobacterium extorquens AM1 demonstrated a trade-off between growth rate and biomass yield. In addition, growth rate and biomass yield were also affected by supplementation of growth medium with different amounts of cobalt. The metabolism changes relating to these growth phenomena as well as the trade-off were investigated in this study. 13C metabolic flux analysis was used to generate a detailed central carbon metabolic flux map with both absolute and normalized flux values. As a result, the major differences between the two variants occurred at the formate node as well as within C3-C4 inter-conversion pathways.more » Higher relative fluxes through formyltetrahydrofolate ligase, phosphoenolpyruvate carboxylase, and malic enzyme led to higher biomass yield, while higher relative fluxes through pyruvate kinase and pyruvate dehydrogenase led to higher growth rate. These results were then tested by phenotypic studies on three mutants (null pyk, null pck mutant and null dme mutant) in both variants, which agreed with the model prediction. In this study, 13C metabolic flux analysis for two strain variants of M. extorquens AM1 successfully identified metabolic pathways contributing to the trade-off between cell growth and biomass yield. Phenotypic analysis of mutants deficient in corresponding genes supported the conclusion that C3-C4 inter-conversion strategies were the major response to the trade-off.« less

Testing the performance of technical trading rules in the Chinese markets based on superior predictive test

NASA Astrophysics Data System (ADS)

Wang, Shan; Jiang, Zhi-Qiang; Li, Sai-Ping; Zhou, Wei-Xing

2015-12-01

Technical trading rules have a long history of being used by practitioners in financial markets. The profitable ability and efficiency of technical trading rules are yet controversial. In this paper, we test the performance of more than seven thousand traditional technical trading rules on the Shanghai Securities Composite Index (SSCI) from May 21, 1992 through June 30, 2013 and China Securities Index 300 (CSI 300) from April 8, 2005 through June 30, 2013 to check whether an effective trading strategy could be found by using the performance measurements based on the return and Sharpe ratio. To correct for the influence of the data-snooping effect, we adopt the Superior Predictive Ability test to evaluate if there exists a trading rule that can significantly outperform the benchmark. The result shows that for SSCI, technical trading rules offer significant profitability, while for CSI 300, this ability is lost. We further partition the SSCI into two sub-series and find that the efficiency of technical trading in sub-series, which have exactly the same spanning period as that of CSI 300, is severely weakened. By testing the trading rules on both indexes with a five-year moving window, we find that during the financial bubble from 2005 to 2007, the effectiveness of technical trading rules is greatly improved. This is consistent with the predictive ability of technical trading rules which appears when the market is less efficient.

Egg number-egg size: an important trade-off in parasite life history strategies.

PubMed

Cavaleiro, Francisca I; Santos, Maria J

2014-03-01

Parasites produce from just a few to many eggs of variable size, but our understanding of the factors driving variation in these two life history traits at the intraspecific level is still very fragmentary. This study evaluates the importance of performing multilevel analyses on egg number and egg size, while characterising parasite life history strategies. A total of 120 ovigerous females of Octopicola superba (Copepoda: Octopicolidae) (one sample (n=30) per season) were characterised with respect to different body dimensions (total length; genital somite length) and measures of reproductive effort (fecundity; mean egg diameter; total reproductive effort; mean egg sac length). While endoparasites are suggested to follow both an r- and K-strategy simultaneously, the evidence found in this and other studies suggests that environmental conditions force ectoparasites into one of the two alternatives. The positive and negative skewness of the distributions of fecundity and mean egg diameter, respectively, suggest that O. superba is mainly a K-strategist (i.e. produces a relatively small number of large, well provisioned eggs). Significant sample differences were recorded concomitantly for all body dimensions and measures of reproductive effort, while a general linear model detected a significant influence of season*parasite total length in both egg number and size. This evidence suggests adaptive phenotypic plasticity in body dimensions and size-mediated changes in egg production. Seasonal changes in partitioning of resources between egg number and size resulted in significant differences in egg sac length but not in total reproductive effort. Evidence for a trade-off between egg number and size was found while controlling for a potential confounding effect of parasite total length. However, this trade-off became apparent only at high fecundity levels, suggesting a state of physiological exhaustion. Copyright © 2014 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Size evolution in microorganisms masks trade-offs predicted by the growth rate hypothesis.

PubMed

Gounand, Isabelle; Daufresne, Tanguy; Gravel, Dominique; Bouvier, Corinne; Bouvier, Thierry; Combe, Marine; Gougat-Barbera, Claire; Poly, Franck; Torres-Barceló, Clara; Mouquet, Nicolas

2016-12-28

Adaptation to local resource availability depends on responses in growth rate and nutrient acquisition. The growth rate hypothesis (GRH) suggests that growing fast should impair competitive abilities for phosphorus and nitrogen due to high demand for biosynthesis. However, in microorganisms, size influences both growth and uptake rates, which may mask trade-offs and instead generate a positive relationship between these traits (size hypothesis, SH). Here, we evolved a gradient of maximum growth rate (μ max ) from a single bacterium ancestor to test the relationship among μ max , competitive ability for nutrients and cell size, while controlling for evolutionary history. We found a strong positive correlation between μ max and competitive ability for phosphorus, associated with a trade-off between μ max and cell size: strains selected for high μ max were smaller and better competitors for phosphorus. Our results strongly support the SH, while the trade-offs expected under GRH were not apparent. Beyond plasticity, unicellular populations can respond rapidly to selection pressure through joint evolution of their size and maximum growth rate. Our study stresses that physiological links between these traits tightly shape the evolution of competitive strategies. © 2016 The Author(s).

Filtering as a reasoning-control strategy: An experimental assessment

NASA Technical Reports Server (NTRS)

Pollack, Martha E.

1994-01-01

In dynamic environments, optimal deliberation about what actions to perform is impossible. Instead, it is sometimes necessary to trade potential decision quality for decision timeliness. One approach to achieving this trade-off is to endow intelligent agents with meta-level strategies that provide them guidance about when to reason (and what to reason about) and when to act. We describe our investigations of a particular meta-level reasoning strategy, filtering, in which an agent commits to the goals it has already adopted, and then filters from consideration new options that would conflict with the successful completion of existing goals. To investigate the utility of filtering, a series of experiments was conducted using the Tileworld testbed. Previous experiments conducted by Kinny and Georgeff used an earlier version of the Tileworld to demonstrate the feasibility of filtering. Results are presented that replicate and extend those of Kinny and Georgeff and demonstrate some significant environmental influences on the value of filtering.

Mixed infections may promote diversification of mutualistic symbionts: why are there ineffective rhizobia?

PubMed

Friesen, M L; Mathias, A

2010-02-01

While strategy variation is a key feature of symbiotic mutualisms, little work focuses on the origin of this diversity. Rhizobia strategies range from mutualistic nitrogen fixers to parasitic nonfixers that hoard plant resources to increase their own survival in soil. Host plants reward beneficial rhizobia with higher nodule growth rates, generating a trade-off between reproduction in nodules and subsequent survival in soil. However, hosts might not discriminate between strains in mixed infections, allowing nonfixing strains to escape sanctions. We construct an adaptive dynamics model of symbiotic nitrogen-fixation and find general situations where symbionts undergo adaptive diversification, but in most situations complete nonfixers do not evolve. Social conflict in mixed infections when symbionts face a survival-reproduction trade-off can drive the origin of some coexisting symbiont strategies, where less mutualistic strains exploit benefits generated by better mutualists.

Do Not Fear Your Opponent: Suboptimal Changes of a Prevention Strategy when Facing Stronger Opponents

ERIC Educational Resources Information Center

Slezak, Diego Fernandez; Sigman, Mariano

2012-01-01

The time spent making a decision and its quality define a widely studied trade-off. Some models suggest that the time spent is set to optimize reward, as verified empirically in simple-decision making experiments. However, in a more complex perspective compromising components of regulation focus, ambitions, fear, risk and social variables,…

Infection with some infectious bursal disease virus pathotypes produces virus in chicken muscle tissue and the role of humoral immunity as a mitigation strategy

USDA-ARS?s Scientific Manuscript database

Infectious bursal disease virus (IBDV) causes important economic losses to the chicken industries worldwide and impacts chicken meat trade in countries with self-declared freedom. The aim of this study was to determine the frequency and titers of IBDV in primary lymphoid tissues and meat of infecte...

Intra-EU agricultural trade, virtual water flows and policy implications.

PubMed

Antonelli, M; Tamea, S; Yang, H

2017-06-01

The development of approaches to tackle the European Union (EU) water-related challenges and shift towards sustainable water management and use is one of the main objectives of Horizon 2020, the EU strategy to lead a smart, sustainable and inclusive growth. The EU is an increasingly water challenged area and is a major agricultural trader. As agricultural trade entails an exchange of water embodied in goods as a factor of production, this study investigates the region's water-food-trade nexus by analysing intra-regional virtual water trade (VWT) in agricultural products. The analysed period (1993-2011) comprises the enactment of the Water Framework Directive (WFD) in the year 2000. Aspects of the VWT that are relevant for the WFD are explored. The EU is a net importer of virtual water (VW) from the rest of the world, but intra-regional VWT represents 46% of total imports and 75% of total exports. Five countries account for 60% of total VW imports (Germany, France, Italy, The Netherlands, Belgium) and 65% of total VW exports (The Netherlands, France, Germany, Belgium and Spain). Intra-EU VWT more than doubled over the period considered, while trade with extra-EU countries did not show such a marked trend. In the same period, blue VWT increased significantly within the region and net import from the rest of the world slightly decreased. Water scarce countries, such as Spain and Italy, are major exporters of blue water in the region. The traded volumes of VW have been increasing almost monotonically over the years, and with a substantial increase after 2000. The overall trend in changes in VWT does not seem to be in accordance with the WFD goals. This study demonstrated that VWT analyses can help evaluate intertwining effects of water, agriculture and trade policies which are often made separately in respective sectors. Copyright © 2017 Elsevier B.V. All rights reserved.

Evolutionary trade-offs in plants mediate the strength of trophic cascades.

PubMed

Mooney, Kailen A; Halitschke, Rayko; Kessler, Andre; Agrawal, Anurag A

2010-03-26

Predators determine herbivore and plant biomass via so-called trophic cascades, and the strength of such effects is influenced by ecosystem productivity. To determine whether evolutionary trade-offs among plant traits influence patterns of trophic control, we manipulated predators and soil fertility and measured impacts of a major herbivore (the aphid Aphis nerii) on 16 milkweed species (Asclepias spp.) in a phylogenetic field experiment. Herbivore density was determined by variation in predation and trade-offs between herbivore resistance and plant growth strategy. Neither herbivore density nor predator effects on herbivores predicted the cascading effects of predators on plant biomass. Instead, cascade strength was strongly and positively associated with milkweed response to soil fertility. Accordingly, contemporary patterns of trophic control are driven by evolutionary convergent trade-offs faced by plants.

Evolution of trophic transmission in parasites: Why add intermediate hosts?

USGS Publications Warehouse

Choisy, Marc; Brown, Sam P.; Lafferty, Kevin D.; Thomas, Frédéric

2003-01-01

Although multihost complex life cycles (CLCs) are common in several distantly related groups of parasites, their evolution remains poorly understood. In this article, we argue that under particular circumstances, adding a second host to a single-host life cycle is likely to enhance transmission (i.e., reaching the target host). For instance, in several situations, the propagules of a parasite exploiting a predator species will achieve a higher host-finding success by encysting in a prey of the target predator than by other dispersal modes. In such a case, selection should favor the transition from a singleto a two-host life cycle that includes the prey species as an intermediate host. We use an optimality model to explore this idea, and we discuss it in relation to dispersal strategies known among free-living species, especially animal dispersal. The model found that selection favored a complex life cycle only if intermediate hosts were more abundant than definitive hosts. The selective value of a complex life cycle increased with predation rates by definitive hosts on intermediate hosts. In exploring trade-offs between transmission strategies, we found that more costly trade-offs made it more difficult to evolve a CLC while less costly trade-offs between traits could favor a mixed strategy.

Fruit flies may face a nutrient-dependent life-history trade-off between secondary sexual trait quality, survival and developmental rate.

PubMed

Gray, Lindsey J; Simpson, Stephen J; Polak, Michal

2018-01-01

Optimal life-history strategies are those that best allocate finite environmental resources to competing traits. We used the geometric framework for nutrition to evaluate life-history strategies followed by Drosophila melanogaster by measuring the condition-dependent performance of life-history traits, including the morphology of male secondary sexual characters, sex combs. We found that depending on their rearing environment flies faced different forms of trait trade-offs and accordingly followed different life-history strategies. High-energy, high-carbohydrate, low-protein diets supported development of the largest and most symmetrical sex combs, however, consistent with handicap models of sexual selection these foods were associated with reduced fly survival and developmental rate. Expressing the highest quality sex combs may have required secondary sexual trait quality to be traded-off with developmental rate, and our results indicated that flies unable to slow development died. As larval nutritional environments are predominantly determined by female oviposition substrate choice, we tested where mated female flies laid the most eggs. Mothers chose high-energy, high-protein foods associated with rapid larval development. Mothers avoided high-carbohydrate foods associated with maximal sex comb expression, showing they may avoid producing fewer 'sexy' sons in favour of producing offspring that develop rapidly. Copyright © 2017 Elsevier Ltd. All rights reserved.

Assessing the land resource-food price nexus of the Sustainable Development Goals.

PubMed

Obersteiner, Michael; Walsh, Brian; Frank, Stefan; Havlík, Petr; Cantele, Matthew; Liu, Junguo; Palazzo, Amanda; Herrero, Mario; Lu, Yonglong; Mosnier, Aline; Valin, Hugo; Riahi, Keywan; Kraxner, Florian; Fritz, Steffen; van Vuuren, Detlef

2016-09-01

The 17 Sustainable Development Goals (SDGs) call for a comprehensive new approach to development rooted in planetary boundaries, equity, and inclusivity. The wide scope of the SDGs will necessitate unprecedented integration of siloed policy portfolios to work at international, regional, and national levels toward multiple goals and mitigate the conflicts that arise from competing resource demands. In this analysis, we adopt a comprehensive modeling approach to understand how coherent policy combinations can manage trade-offs among environmental conservation initiatives and food prices. Our scenario results indicate that SDG strategies constructed around Sustainable Consumption and Production policies can minimize problem-shifting, which has long placed global development and conservation agendas at odds. We conclude that Sustainable Consumption and Production policies (goal 12) are most effective at minimizing trade-offs and argue for their centrality to the formulation of coherent SDG strategies. We also find that alternative socioeconomic futures-mainly, population and economic growth pathways-generate smaller impacts on the eventual achievement of land resource-related SDGs than do resource-use and management policies. We expect that this and future systems analyses will allow policy-makers to negotiate trade-offs and exploit synergies as they assemble sustainable development strategies equal in scope to the ambition of the SDGs.

Assessing the land resource–food price nexus of the Sustainable Development Goals

PubMed Central

Obersteiner, Michael; Walsh, Brian; Frank, Stefan; Havlík, Petr; Cantele, Matthew; Liu, Junguo; Palazzo, Amanda; Herrero, Mario; Lu, Yonglong; Mosnier, Aline; Valin, Hugo; Riahi, Keywan; Kraxner, Florian; Fritz, Steffen; van Vuuren, Detlef

2016-01-01

The 17 Sustainable Development Goals (SDGs) call for a comprehensive new approach to development rooted in planetary boundaries, equity, and inclusivity. The wide scope of the SDGs will necessitate unprecedented integration of siloed policy portfolios to work at international, regional, and national levels toward multiple goals and mitigate the conflicts that arise from competing resource demands. In this analysis, we adopt a comprehensive modeling approach to understand how coherent policy combinations can manage trade-offs among environmental conservation initiatives and food prices. Our scenario results indicate that SDG strategies constructed around Sustainable Consumption and Production policies can minimize problem-shifting, which has long placed global development and conservation agendas at odds. We conclude that Sustainable Consumption and Production policies (goal 12) are most effective at minimizing trade-offs and argue for their centrality to the formulation of coherent SDG strategies. We also find that alternative socioeconomic futures—mainly, population and economic growth pathways—generate smaller impacts on the eventual achievement of land resource–related SDGs than do resource-use and management policies. We expect that this and future systems analyses will allow policy-makers to negotiate trade-offs and exploit synergies as they assemble sustainable development strategies equal in scope to the ambition of the SDGs. PMID:27652336

Impacts of licensed premises trading hour policies on alcohol-related harms.

PubMed

Atkinson, Jo-An; Prodan, Ante; Livingston, Michael; Knowles, Dylan; O'Donnell, Eloise; Room, Robin; Indig, Devon; Page, Andrew; McDonnell, Geoff; Wiggers, John

2018-07-01

Evaluations of alcohol policy changes demonstrate that restriction of trading hours of both 'on'- and 'off'-licence venues can be an effective means of reducing rates of alcohol-related harm. Despite this, the effects of different trading hour policy options over time, accounting for different contexts and demographic characteristics, and the common co-occurrence of other harm reduction strategies in trading hour policy initiatives, are difficult to estimate. The aim of this study was to use dynamic simulation modelling to compare estimated impacts over time of a range of trading hour policy options on various indicators of acute alcohol-related harm. An agent-based model of alcohol consumption in New South Wales, Australia was developed using existing research evidence, analysis of available data and a structured approach to incorporating expert opinion. Five policy scenarios were simulated, including restrictions to trading hours of on-licence venues and extensions to trading hours of bottle shops. The impact of the scenarios on four measures of alcohol-related harm were considered: total acute harms, alcohol-related violence, emergency department (ED) presentations and hospitalizations. Simulation of a 3 a.m. (rather than 5 a.m.) closing time resulted in an estimated 12.3 ± 2.4% reduction in total acute alcohol-related harms, a 7.9 ± 0.8% reduction in violence, an 11.9 ± 2.1% reduction in ED presentations and a 9.5 ± 1.8% reduction in hospitalizations. Further reductions were achieved simulating a 1 a.m. closing time, including a 17.5 ± 1.1% reduction in alcohol-related violence. Simulated extensions to bottle shop trading hours resulted in increases in rates of all four measures of harm, although most of the effects came from increasing operating hours from 10 p.m. to 11 p.m. An agent-based simulation model suggests that restricting trading hours of licensed venues reduces rates of alcohol-related harm and extending trading hours of bottle shops increases rates of alcohol-related harm. The model can estimate the effects of a range of policy options. © 2018 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.

Temperature-stress resistance and tolerance along a latitudinal cline in North American Arabidopsis lyrata.

PubMed

Wos, Guillaume; Willi, Yvonne

2015-01-01

The study of latitudinal gradients can yield important insights into adaptation to temperature stress. Two strategies are available: resistance by limiting damage, or tolerance by reducing the fitness consequences of damage. Here we studied latitudinal variation in resistance and tolerance to frost and heat and tested the prediction of a trade-off between the two strategies and their costliness. We raised plants of replicate maternal seed families from eight populations of North American Arabidopsis lyrata collected along a latitudinal gradient in climate chambers and exposed them repeatedly to either frost or heat stress, while a set of control plants grew under standard conditions. When control plants reached maximum rosette size, leaf samples were exposed to frost and heat stress, and electrolyte leakage (PEL) was measured and treated as an estimate of resistance. Difference in maximum rosette size between stressed and control plants was used as an estimate of tolerance. Northern populations were more frost resistant, and less heat resistant and less heat tolerant, but-unexpectedly-they were also less frost tolerant. Negative genetic correlations between resistance and tolerance to the same and different thermal stress were generally not significant, indicating only weak trade-offs. However, tolerance to frost was consistently accompanied by small size under control conditions, which may explain the non-adaptive latitudinal pattern for frost tolerance. Our results suggest that adaptation to frost and heat is not constrained by trade-offs between them. But the cost of frost tolerance in terms of plant size reduction may be important for the limits of species distributions and climate niches.

Interplanetary Electric Propulsion Uranus Mission Trades Supporting the Decadal Survey

NASA Technical Reports Server (NTRS)

Dankanich, John W.; McAdams, James

2011-01-01

The Decadal Survey Committee was tasked to develop a comprehensive science and mission strategy for planetary science that updates and extends the National Academies Space Studies Board s current solar system exploration decadal survey. A Uranus orbiter mission has been evaluated as a part of this 2013-2022 Planetary Science Decadal Survey. A comprehensive Uranus orbiter mission design was completed, including a broad search of interplanetary electric propulsion transfer options. The scope of interplanetary trades was limited to electric propulsion concepts, both solar and radioisotope powered. Solar electric propulsion offers significant payloads to Uranus. Inserted mass into the initial science orbit due is highly sensitive to transfer time due to arrival velocities. The recommended baseline trajectory is a 13 year transfer with an Atlas 551, a 1+1 NEXT stage with 15 kW of power using an EEJU trajectory and a 1,000km EGA flyby altitude constraint. This baseline delivers over 2,000kg into the initial science orbit. Interplanetary trajectory trades and sensitivity analyses are presented herein.

Animal Health Surveillance in Scotland in 2030: Using Scenario Planning to Develop Strategies in the Context of "Brexit".

PubMed

Boden, Lisa A; Auty, Harriet; Reeves, Aaron; Rydevik, Gustaf; Bessell, Paul; McKendrick, Iain J

2017-01-01

Animal health surveillance is necessary to protect human and animal health, rural economies, and the environment from the consequences of large-scale disease outbreaks. In Scotland, since the Kinnaird review in 2011, efforts have been made to engage with stakeholders to ensure that the strategic goals of surveillance are better aligned with the needs of the end-users and other beneficiaries. The aims of this study were to engage with Scottish surveillance stakeholders and multidisciplinary experts to inform the future long-term strategy for animal health surveillance in Scotland. In this paper, we describe the use of scenario planning as an effective tool for the creation and exploration of five plausible long-term futures; we describe prioritization of critical drivers of change (i.e., international trade policy, data-sharing philosophies, and public versus private resourcing of surveillance capacity) that will unpredictably influence the future implementation of animal health surveillance activities. We present 10 participant-developed strategies to support 3 long-term visions to improve future resilience of animal health surveillance and contingency planning for animal and zoonotic disease outbreaks in Scotland. In the absence of any certainty about the nature of post-Brexit trade agreements for agriculture, participants considered the best investments for long-term resilience to include data collection strategies to improve animal health benchmarking, user-benefit strategies to improve digital literacy in farming communities, and investment strategies to increase veterinary and scientific research capacity in rural areas. This is the first scenario planning study to explore stakeholder beliefs and perceptions about important environmental, technological, societal, political, and legal drivers (in addition to epidemiological "risk factors") and effective strategies to manage future uncertainties for both the Scottish livestock industry and animal health surveillance after Brexit. This insight from stakeholders is important to improve uptake and implementation of animal heath surveillance activities and the future resilience of the livestock industry. The conclusions drawn from this study are applicable not only to Scotland but to other countries and international organizations involved in global animal health surveillance activities.

Animal Health Surveillance in Scotland in 2030: Using Scenario Planning to Develop Strategies in the Context of “Brexit”

PubMed Central

Boden, Lisa A.; Auty, Harriet; Reeves, Aaron; Rydevik, Gustaf; Bessell, Paul; McKendrick, Iain J.

2017-01-01

Animal health surveillance is necessary to protect human and animal health, rural economies, and the environment from the consequences of large-scale disease outbreaks. In Scotland, since the Kinnaird review in 2011, efforts have been made to engage with stakeholders to ensure that the strategic goals of surveillance are better aligned with the needs of the end-users and other beneficiaries. The aims of this study were to engage with Scottish surveillance stakeholders and multidisciplinary experts to inform the future long-term strategy for animal health surveillance in Scotland. In this paper, we describe the use of scenario planning as an effective tool for the creation and exploration of five plausible long-term futures; we describe prioritization of critical drivers of change (i.e., international trade policy, data-sharing philosophies, and public versus private resourcing of surveillance capacity) that will unpredictably influence the future implementation of animal health surveillance activities. We present 10 participant-developed strategies to support 3 long-term visions to improve future resilience of animal health surveillance and contingency planning for animal and zoonotic disease outbreaks in Scotland. In the absence of any certainty about the nature of post-Brexit trade agreements for agriculture, participants considered the best investments for long-term resilience to include data collection strategies to improve animal health benchmarking, user-benefit strategies to improve digital literacy in farming communities, and investment strategies to increase veterinary and scientific research capacity in rural areas. This is the first scenario planning study to explore stakeholder beliefs and perceptions about important environmental, technological, societal, political, and legal drivers (in addition to epidemiological “risk factors”) and effective strategies to manage future uncertainties for both the Scottish livestock industry and animal health surveillance after Brexit. This insight from stakeholders is important to improve uptake and implementation of animal heath surveillance activities and the future resilience of the livestock industry. The conclusions drawn from this study are applicable not only to Scotland but to other countries and international organizations involved in global animal health surveillance activities. PMID:29230402

77 FR 26564 - Advisory Committee on Commercial Operations of Customs and Border Protection (COAC)

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-04

... National Strategy for Global Supply Chain Security. The work of the Trade Facilitation Subcommittee... Strategy for Global Supply Chain Security as it relates to the Committee's effort to solicit, consolidate... chain management project. The Anti-Dumping/Countervailing Duties Subcommittee work on educational...

Immune function trade-offs in response to parasite threats.

PubMed

Kirschman, Lucas J; Quade, Adam H; Zera, Anthony J; Warne, Robin W

2017-04-01

Immune function is often involved in physiological trade-offs because of the energetic costs of maintaining constitutive immunity and mounting responses to infection. However, immune function is a collection of discrete immunity factors and animals should allocate towards factors that combat the parasite threat with the highest fitness cost. For example, animals on dispersal fronts of expanding population may be released from density-dependent diseases. The costs of immunity, however, and life history trade-offs in general, are often context dependent. Trade-offs are often most apparent under conditions of unusually limited resources or when animals are particularly stressed, because the stress response can shift priorities. In this study we tested how humoral and cellular immune factors vary between phenotypes of a wing dimorphic cricket and how physiological stress influences these immune factors. We measured constitutive lysozyme activity, a humoral immune factor, and encapsulation response, a cellular immune factor. We also stressed the crickets with a sham predator in a full factorial design. We found that immune strategy could be explained by the selective pressures encountered by each morph and that stress decreased encapsulation, but not lysozyme activity. These results suggest a possible trade-off between humoral and cellular immunity. Given limited resources and the expense of immune factors, parasite pressures could play a key factor in maintaining insect polyphenism via disruptive selection. Copyright © 2017 Elsevier Ltd. All rights reserved.

Implications of the cattle trade network in Cameroon for regional disease prevention and control

PubMed Central

Motta, Paolo; Porphyre, Thibaud; Handel, Ian; Hamman, Saidou M.; Ngu Ngwa, Victor; Tanya, Vincent; Morgan, Kenton; Christley, Rob; Bronsvoort, Barend M. deC.

2017-01-01

Movement of live animals is a major risk factor for the spread of livestock diseases and zoonotic infections. Understanding contact patterns is key to informing cost-effective surveillance and control strategies. In West and Central Africa some of the most rapid urbanization globally is expected to increase the demand for animal-source foods and the need for safer and more efficient animal production. Livestock trading points represent a strategic contact node in the dissemination of multiple pathogens. From October 2014 to May 2015 official transaction records were collected and a questionnaire-based survey was carried out in cattle markets throughout Western and Central-Northern Cameroon. The data were used to analyse the cattle trade network including a total of 127 livestock markets within Cameroon and five neighboring countries. This study explores for the first time the influence of animal trade on infectious disease spread in the region. The investigations showed that national borders do not present a barrier against pathogen dissemination and that non-neighbouring countries are epidemiologically connected, highlighting the importance of a regional approach to disease surveillance, prevention and control. Furthermore, these findings provide evidence for the benefit of strategic risk-based approaches for disease monitoring, surveillance and control, as well as for communication and training purposes through targeting key regions, highly connected livestock markets and central trading links. PMID:28266589

Implications of the cattle trade network in Cameroon for regional disease prevention and control

NASA Astrophysics Data System (ADS)

Motta, Paolo; Porphyre, Thibaud; Handel, Ian; Hamman, Saidou M.; Ngu Ngwa, Victor; Tanya, Vincent; Morgan, Kenton; Christley, Rob; Bronsvoort, Barend M. Dec.

2017-03-01

Movement of live animals is a major risk factor for the spread of livestock diseases and zoonotic infections. Understanding contact patterns is key to informing cost-effective surveillance and control strategies. In West and Central Africa some of the most rapid urbanization globally is expected to increase the demand for animal-source foods and the need for safer and more efficient animal production. Livestock trading points represent a strategic contact node in the dissemination of multiple pathogens. From October 2014 to May 2015 official transaction records were collected and a questionnaire-based survey was carried out in cattle markets throughout Western and Central-Northern Cameroon. The data were used to analyse the cattle trade network including a total of 127 livestock markets within Cameroon and five neighboring countries. This study explores for the first time the influence of animal trade on infectious disease spread in the region. The investigations showed that national borders do not present a barrier against pathogen dissemination and that non-neighbouring countries are epidemiologically connected, highlighting the importance of a regional approach to disease surveillance, prevention and control. Furthermore, these findings provide evidence for the benefit of strategic risk-based approaches for disease monitoring, surveillance and control, as well as for communication and training purposes through targeting key regions, highly connected livestock markets and central trading links.

Fair Trade Metaphor as a Control Privacy Method for Pervasive Environments: Concepts and Evaluation.

PubMed

Esquivel, Abraham; Haya, Pablo; Alamán, Xavier

2015-06-16

This paper presents a proof of concept from which the metaphor of "fair trade" is validated as an alternative to manage the private information of users. Our privacy solution deals with user's privacy as a tradable good for obtaining environmental services. Thus, users gain access to more valuable services as they share more personal information. This strategy, combined with optimistic access control and transaction registry mechanisms, enhances users' confidence in the system while encouraging them to share their information, with the consequent benefit for the community. The study results are promising considering the user responses regarding the usefulness, ease of use, information classification and perception of control with the mechanisms proposed by the metaphor.

Natural mortality: Its ecology, how it shapes fish life histories, and why it may be increased by fishing

NASA Astrophysics Data System (ADS)

Jørgensen, Christian; Holt, Rebecca E.

2013-01-01

A stronger focus on natural mortality may be required to better understand contemporary changes in fish life histories and behaviour and their responses to anthropogenic drivers. Firstly, natural mortality is the selection under which fish evolved in the first place, so a theoretical understanding of effects of natural mortality alone is needed. Secondly, due to trade-offs, most organismal functions can only be achieved at some cost in terms of survival. Several trade-offs might need to be analysed simultaneously with effects on natural mortality being a common currency. Thirdly, there is scattered evidence that natural mortality has been increasing, some would say dramatically, in some fished stocks, which begs explanations. Fourthly, natural mortality most often implies transfer of mass and energy from one species to another, and therefore has foodweb and ecosystem consequences. We therefore analyse a model for evolution of fish life histories and behaviour, where state-dependent energy-allocation and growth strategies are found by optimization. Natural mortality is split into five different components, each specified as the outcome of individual traits and ecological trade-offs: a fixed baseline mortality; size-dependent predation; risk-dependent growth strategy; a fixed mortality when sexually mature; and mortality increasing with reproductive investment. The analysis is repeated with and without fishing. Each component of natural mortality has consequences for optimal life history strategies. Beyond earlier models, we show i) how the two types of reproductive mortality sometimes have similar and sometimes contrasting effects on life history evolution, ii) how ecosystem properties such as food availability and predation levels have stronger effects on optimal strategies than changing other mortality components, and iii) how expected changes in risk-dependent growth strategies are highly variable depending on the type of mortality changed.

Needs of Non-Energy Focused Contractors

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

Liakus, C.

2012-12-01

To better understand the informational needs of non-energy focused contractors, including what information they need to motivate them to become energy-focused, the BARA team studied the type of information provided by the national programs, trade associations, and manufacturers that were researched for the related technical report: Effective Communication of Energy Efficiency. While that report focused on the delivery method, format, and strategy of the information, this study examines the content being put forward.

Needs of Non Energy-Focused Contractors

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

Liaukus, C.

2012-12-01

To better understand the informational needs of non energy-focused contractors, including what information they need to motivate them to become energy-focused, the BARA team studied the type of information provided by the national programs, trade associations, and manufacturers that were researched for the related technical report: Effective Communication of Energy Efficiency. While that report focused on the delivery method, format, and strategy of the information, this study examines the content being put forward.

Strategies of offspring investment and dispersal in a spatially structured environment: a theoretical study using ants.

PubMed

Cronin, Adam L; Loeuille, Nicolas; Monnin, Thibaud

2016-02-05

Offspring investment strategies vary markedly between and within taxa, and much of this variation is thought to stem from the trade-off between offspring size and number. While producing larger offspring can increase their competitive ability, this often comes at a cost to their colonization ability. This competition-colonization trade-off (CCTO) is thought to be an important mechanism supporting coexistence of alternative strategies in a wide range of taxa. However, the relative importance of an alternative and possibly synergistic mechanism-spatial structuring of the environment-remains the topic of some debate. In this study, we explore the influence of these mechanisms on metacommunity structure using an agent-based model built around variable life-history traits. Our model combines explicit resource competition and spatial dynamics, allowing us to tease-apart the influence of, and explore the interaction between, the CCTO and the spatial structure of the environment. We test our model using two reproductive strategies which represent extremes of the CCTO and are common in ants. Our simulations show that colonisers outperform competitors in environments subject to higher temporal and spatial heterogeneity and are favoured when agents mature late and invest heavily in reproduction, whereas competitors dominate in low-disturbance, high resource environments and when maintenance costs are low. Varying life-history parameters has a marked influence on coexistence conditions and yields evolutionary stable strategies for both modes of reproduction. Nonetheless, we show that these strategies can coexist over a wide range of life-history and environmental parameter values, and that coexistence can in most cases be explained by a CCTO. By explicitly considering space, we are also able to demonstrate the importance of the interaction between dispersal and landscape structure. The CCTO permits species employing different reproductive strategies to coexist over a wide range of life-history and environmental parameters, and is likely to be an important factor in structuring ant communities. Our consideration of space highlights the importance of dispersal, which can limit the success of low-dispersers through kin competition, and enhance coexistence conditions for different strategies in spatially structured environments.

How do new dams impact downstream countries? - A screening approach to identify the best compromise assets and negotiate their designs

NASA Astrophysics Data System (ADS)

Geressu, Robel; Harou, Julien

2015-04-01

Water use rights are disputed in many transboundary basins. Even when water projects can benefit all, agreeing on cost and benefit sharing can be difficult where stakeholders have conflicting preferences on the designs and use of proposed water infrastructures. This study suggests a combination of many objective optimization and multi-criteria ranking methods to support negotiations regarding designs of new assets. The method allows competing users to assess development options based on their individual perspectives and agree on designs by incorporating coordination strategies into multi-reservoir system designs. We demonstrate a hypothetical negotiation on proposed Blue Nile reservoirs. The result form a set of Pareto-optimal designs i.e., reservoirs, storage capacity and their operating rules, and power trade, cost sharing and/or financing coordination strategies, which maximize benefit to all countries and show which trade-offs are implied by which designs. The approach fulfils decision-maker's desire to understand a) the critical design parameters that affect various objectives and b) how coordination mechanisms would enable them to incur benefits from proposed new dams.

Global health risks and cosmopolitisation: from emergence to interference.

PubMed

Figuié, Muriel

2013-02-01

According to Beck's 'World at Risk' theory, global risks push nations towards a cosmopolitisation of their health policy and open opportunities for a democratic turn. This article provides an empirical analysis of Beck's theory, based on the experience of Vietnamese authorities from 2003 to 2007 in managing the emerging avian flu virus. It shows how Vietnam's framing of avian flu has shifted, under the pressure from international organisations and the US administration, from an epizootic and zoonotic risk (or a classic risk) to a pandemic threat (or a late modern risk). Vietnam's response was part of its overall strategy to join the World Trade Organization and it was limited by Vietnam's defence of its sovereignty. This strategy has been successful for Vietnam but has limited the possibility of cosmopolitan and democratic transformations. The case study highlights the constructed dimension of risks of late modernity and their possible instrumentalisation: it minimises the role of a community of fear relative to a community of trade. © 2013 The Author. Sociology of Health & Illness © 2013 Foundation for the Sociology of Health & Illness/Blackwell Publishing Ltd.

An interval programming model for continuous improvement in micro-manufacturing

NASA Astrophysics Data System (ADS)

Ouyang, Linhan; Ma, Yizhong; Wang, Jianjun; Tu, Yiliu; Byun, Jai-Hyun

2018-03-01

Continuous quality improvement in micro-manufacturing processes relies on optimization strategies that relate an output performance to a set of machining parameters. However, when determining the optimal machining parameters in a micro-manufacturing process, the economics of continuous quality improvement and decision makers' preference information are typically neglected. This article proposes an economic continuous improvement strategy based on an interval programming model. The proposed strategy differs from previous studies in two ways. First, an interval programming model is proposed to measure the quality level, where decision makers' preference information is considered in order to determine the weight of location and dispersion effects. Second, the proposed strategy is a more flexible approach since it considers the trade-off between the quality level and the associated costs, and leaves engineers a larger decision space through adjusting the quality level. The proposed strategy is compared with its conventional counterparts using an Nd:YLF laser beam micro-drilling process.

Top predators induce the evolutionary diversification of intermediate predator species.

PubMed

Zu, Jian; Yuan, Bo; Du, Jianqiang

2015-12-21

We analyze the evolutionary branching phenomenon of intermediate predator species in a tritrophic food chain model by using adaptive dynamics theory. Specifically, we consider the adaptive diversification of an intermediate predator species that feeds on a prey species and is fed upon by a top predator species. We assume that the intermediate predator׳s ability to forage on the prey can adaptively improve, but this comes at the cost of decreased defense ability against the top predator. First, we identify the general properties of trade-off relationships that lead to a continuously stable strategy or to evolutionary branching in the intermediate predator species. We find that if there is an accelerating cost near the singular strategy, then that strategy is continuously stable. In contrast, if there is a mildly decelerating cost near the singular strategy, then that strategy may be an evolutionary branching point. Second, we find that after branching has occurred, depending on the specific shape and strength of the trade-off relationship, the intermediate predator species may reach an evolutionarily stable dimorphism or one of the two resultant predator lineages goes extinct. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

The trade in human organs in Tamil Nadu: the anatomy of regulatory failure.

PubMed

Muraleedharan, Vangal R; Jan, Stephen; Ram Prasad, S

2006-01-01

There has been much recent interest in the trade in human organs in India. This paper examines both the extent to which regulatory controls through the Transplantation of Human Organs Act (1994) are effective in curbing commercialization and the nature of the constraints on the effective implementation of this Act. The study, a politico-economic analysis of health sector regulation, is based on a stakeholder analysis drawing on the views of key decision makers, service providers, organ donors and recipients. The findings indicate widespread acknowledgement of an organs trade and highlight four major constraints on the effective implementation of the Act: the commercial interests of middlemen and service providers, the ambiguities and loopholes in the Act; the low monitoring capacity of the regulatory authorities, and the pressures and responsibilities exerted upon the Authorizing Committees. A feature of the Act is that its implementation is subject to a major incentive compatibility constraint - it is seemingly not in the interests of any of the key players, including the regulatory authorities, to restrict the organ trade. To some extent, this institutional problem is created by the specific nature of the regulatory intervention, and, as a consequence, measures involving straightforward redrafting of the regulation might go some way to addressing this incentive problem. Another solution may entail a 'harm-reduction' strategy involving a controlled trade where procurement and organ matching is carried out by a government agency (this would require, however, the prior resolution of the broader ethical question concerning the legitimacy of such trade).

Operation of Power Grids with High Penetration of Wind Power

NASA Astrophysics Data System (ADS)

Al-Awami, Ali Taleb

The integration of wind power into the power grid poses many challenges due to its highly uncertain nature. This dissertation involves two main components related to the operation of power grids with high penetration of wind energy: wind-thermal stochastic dispatch and wind-thermal coordinated bidding in short-term electricity markets. In the first part, a stochastic dispatch (SD) algorithm is proposed that takes into account the stochastic nature of the wind power output. The uncertainty associated with wind power output given the forecast is characterized using conditional probability density functions (CPDF). Several functions are examined to characterize wind uncertainty including Beta, Weibull, Extreme Value, Generalized Extreme Value, and Mixed Gaussian distributions. The unique characteristics of the Mixed Gaussian distribution are then utilized to facilitate the speed of convergence of the SD algorithm. A case study is carried out to evaluate the effectiveness of the proposed algorithm. Then, the SD algorithm is extended to simultaneously optimize the system operating costs and emissions. A modified multi-objective particle swarm optimization algorithm is suggested to identify the Pareto-optimal solutions defined by the two conflicting objectives. A sensitivity analysis is carried out to study the effect of changing load level and imbalance cost factors on the Pareto front. In the second part of this dissertation, coordinated trading of wind and thermal energy is proposed to mitigate risks due to those uncertainties. The problem of wind-thermal coordinated trading is formulated as a mixed-integer stochastic linear program. The objective is to obtain the optimal tradeoff bidding strategy that maximizes the total expected profits while controlling trading risks. For risk control, a weighted term of the conditional value at risk (CVaR) is included in the objective function. The CVaR aims to maximize the expected profits of the least profitable scenarios, thus improving trading risk control. A case study comparing coordinated with uncoordinated bidding strategies depending on the trader's risk attitude is included. Simulation results show that coordinated bidding can improve the expected profits while significantly improving the CVaR.

Leveraging Trade Agreements to Meet U.S. Security Aims

DTIC Science & Technology

2016-04-08

TO MEET U.S. SECURITY AIMS 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Sd. PROJECT NUMBER LTC Allysa A. Kropp (USARNG) Se. TASK NUMBER 5f...Sanctions Programs and Country Information,” under “Resource Center, Financial Sanctions, Programs ,” https’.//wwiv.treasurv.gov/resource center/sanctions... Program , and economic integration of former adversaries through U.S. trade policy.7 In the National Security Strategy, President Obama underscored the

Domestic Agricultural Subsidies’ Impacts on National Security Objectives Relative to the SOUTHCOM AOR

DTIC Science & Technology

2009-06-12

x6x75745r2140160 (accessed November 17, 2008). Haggblade, Steven, Peter B. R. Hazell, and Thomas Reardon. Transforming the Rural Nonfarm Economy...Commander‘s Posture Statement to Congress, recognize the role of economic development and liberalized trade in promoting global and regional security...National Security Strategy down to the SOUTHCOM Commander‘s Posture Statement to Congress, recognize the role of economic development and liberalized trade

Early life adversity increases foraging and information gathering in European starlings, Sturnus vulgaris

PubMed Central

Andrews, Clare; Viviani, Jérémie; Egan, Emily; Bedford, Thomas; Brilot, Ben; Nettle, Daniel; Bateson, Melissa

2015-01-01

Animals can insure themselves against the risk of starvation associated with unpredictable food availability by storing energy reserves or gathering information about alternative food sources. The former strategy carries costs in terms of mass-dependent predation risk, while the latter trades off against foraging for food; both trade-offs may be influenced by an individual's developmental history. Here, we consider a possible role of early developmental experience in inducing different mass regulation and foraging strategies in European starlings. We measured the body mass, body condition, foraging effort, food consumption and contrafreeloading (foraging for food hidden in sand when equivalent food is freely available) of adult birds (≥10 months old) that had previously undergone a subtle early life manipulation of food competition (cross-fostering into the highest or lowest ranks in the brood size hierarchy when 2–12 days of age). We found that developmentally disadvantaged birds were fatter in adulthood and differed in foraging behaviour compared with their advantaged siblings. Disadvantaged birds were hyperphagic compared with advantaged birds, but only following a period of food deprivation, and also spent more time contrafreeloading. Advantaged birds experienced a trade-off between foraging success and time spent contrafreeloading, whereas disadvantaged birds faced no such trade-off, owing to their greater foraging efficiency. Thus, developmentally disadvantaged birds appeared to retain a phenotypic memory of increased nestling food competition, employing both energy storage and information-gathering insurance strategies to a greater extent than their advantaged siblings. Our results suggest that subtle early life disadvantage in the form of psychosocial stress and/or food insecurity can leave a lasting legacy on foraging behaviour and mass regulation even in the absence of food insufficiency during development or adulthood. PMID:26566292

Random matrix approach to the dynamics of stock inventory variations

NASA Astrophysics Data System (ADS)

Zhou, Wei-Xing; Mu, Guo-Hua; Kertész, János

2012-09-01

It is well accepted that investors can be classified into groups owing to distinct trading strategies, which forms the basic assumption of many agent-based models for financial markets when agents are not zero-intelligent. However, empirical tests of these assumptions are still very rare due to the lack of order flow data. Here we adopt the order flow data of Chinese stocks to tackle this problem by investigating the dynamics of inventory variations for individual and institutional investors that contain rich information about the trading behavior of investors and have a crucial influence on price fluctuations. We find that the distributions of cross-correlation coefficient Cij have power-law forms in the bulk that are followed by exponential tails, and there are more positive coefficients than negative ones. In addition, it is more likely that two individuals or two institutions have a stronger inventory variation correlation than one individual and one institution. We find that the largest and the second largest eigenvalues (λ1 and λ2) of the correlation matrix cannot be explained by random matrix theory and the projections of investors' inventory variations on the first eigenvector u(λ1) are linearly correlated with stock returns, where individual investors play a dominating role. The investors are classified into three categories based on the cross-correlation coefficients CV R between inventory variations and stock returns. A strong Granger causality is unveiled from stock returns to inventory variations, which means that a large proportion of individuals hold the reversing trading strategy and a small part of individuals hold the trending strategy. Our empirical findings have scientific significance in the understanding of investors' trading behavior and in the construction of agent-based models for emerging stock markets.

Transitions in optimal adaptive strategies for populations in fluctuating environments

NASA Astrophysics Data System (ADS)

Mayer, Andreas; Mora, Thierry; Rivoire, Olivier; Walczak, Aleksandra M.

2017-09-01

Biological populations are subject to fluctuating environmental conditions. Different adaptive strategies can allow them to cope with these fluctuations: specialization to one particular environmental condition, adoption of a generalist phenotype that compromises between conditions, or population-wise diversification (bet hedging). Which strategy provides the largest selective advantage in the long run depends on the range of accessible phenotypes and the statistics of the environmental fluctuations. Here, we analyze this problem in a simple mathematical model of population growth. First, we review and extend a graphical method to identify the nature of the optimal strategy when the environmental fluctuations are uncorrelated. Temporal correlations in environmental fluctuations open up new strategies that rely on memory but are mathematically challenging to study: We present analytical results to address this challenge. We illustrate our general approach by analyzing optimal adaptive strategies in the presence of trade-offs that constrain the range of accessible phenotypes. Our results extend several previous studies and have applications to a variety of biological phenomena, from antibiotic resistance in bacteria to immune responses in vertebrates.

Strategy Space Exploration of a Multi-Agent Model for the Labor Market

NASA Astrophysics Data System (ADS)

de Grande, Pablo; Eguia, Manuel

We present a multi-agent system where typical labor market mechanisms emerge. Based on a few simple rules, our model allows for different interpretative paradigms to be represented and for different scenarios to be tried out. We thoroughly explore the space of possible strategies both for those unemployed and for companies and analyze the trade-off between these strategies regarding global social and economical indicators.

The Methane to Markets Coal Mine Methane Subcommittee meeting

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

NONE

2008-07-01

The presentations (overheads/viewgraphs) include: a report from the Administrative Support Group; strategy updates from Australia, India, Italy, Mexico, Nigeria, Poland and the USA; coal mine methane update and IEA's strategy and activities; the power of VAM - technology application update; the emissions trading market; the voluntary emissions reduction market - creating profitable CMM projects in the USA; an Italian perspective towards a zero emission strategies; and the wrap-up and summary.

Melanin-specific life-history strategies.

PubMed

Emaresi, Guillaume; Bize, Pierre; Altwegg, Res; Henry, Isabelle; van den Brink, Valentijn; Gasparini, Julien; Roulin, Alexandre

2014-02-01

The maintenance of genetic variation is a long-standing issue because the adaptive value of life-history strategies associated with each genetic variant is usually unknown. However, evidence for the coexistence of alternative evolutionary fixed strategies at the population level remains scarce. Because in the tawny owl (Strix aluco) heritable melanin-based coloration shows different physiological and behavioral norms of reaction, we investigated whether coloration is associated with investment in maintenance and reproduction. Light melanic owls had lower adult survival compared to dark melanic conspecifics, and color variation was related to the trade-off between offspring number and quality. When we experimentally enlarged brood size, light melanic males produced more fledglings but in poorer condition, and they were less often recruited in the local breeding population than those of darker melanic conspecifics. Our results also suggest that dark melanic males allocate a constant effort to raise their brood independently of environmental conditions, whereas lighter melanic males finely adjust reproductive effort in relation to changes in environmental conditions. Color traits can therefore be associated with life-history strategies, and stochastic environmental perturbation can temporarily favor one phenotype over others. The existence of fixed strategies implies that some phenotypes can sometimes display a "maladapted" strategy. Long-term population monitoring is therefore vital for a full understanding of how different genotypes deal with trade-offs.

Carbon Emissions Trading and Combined Heat and Power Strategies: Unintended Consequences

ERIC Educational Resources Information Center

Tysseling, John C.; Vosevich, Mary; Boersma, Benjamin R.; Zumwalt, Jefferey A.

2009-01-01

Facility professionals continuously search for projects that reduce energy consumption and operating costs so as to directly benefit their bottom line. Many institutions nationwide have contemplated or made investments in combined heat and power (CHP) projects as a life-cycle strategy to minimize operating costs. However, recent sustainability and…

75 FR 71168 - Self-Regulatory Organizations; BATS Exchange, Inc.; Notice of Filing and Immediate Effectiveness...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-22

... flexibility and the ability to more closely tailor their investment and risk management strategies and... will aid investors by offering opportunities to manage risk and execute a variety of option strategies... to provide investors with additional strikes for investment, trading, and risk management purposes. 2...

76 FR 40969 - Self-Regulatory Organizations; Notice of Filing and Immediate Effectiveness of a Proposed Rule...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-12

... risk management strategies and decisions. Furthermore, the Exchange has had to eliminate option classes... additional short term option classes for investment, trading, and risk management purposes. Finally, the... that various strategies that the investor put into play were disrupted and eliminated when the class...

40 CFR 52.1876 - Control strategy: Nitrogen dioxide.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Control strategy: Nitrogen dioxide. 52...: Nitrogen dioxide. (a) The condition to EPA's approval of the oxides of nitrogen State Implementation Plan... change to the flow control date in the oxides of nitrogen budget trading SIP. (b) [Reserved] [69 FR 13234...

40 CFR 52.1876 - Control strategy: Nitrogen dioxide.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Control strategy: Nitrogen dioxide. 52...: Nitrogen dioxide. (a) The condition to EPA's approval of the oxides of nitrogen State Implementation Plan... change to the flow control date in the oxides of nitrogen budget trading SIP. (b) [Reserved] [69 FR 13234...

40 CFR 52.1876 - Control strategy: Nitrogen dioxide.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Control strategy: Nitrogen dioxide. 52...: Nitrogen dioxide. (a) The condition to EPA's approval of the oxides of nitrogen State Implementation Plan... change to the flow control date in the oxides of nitrogen budget trading SIP. (b) [Reserved] [69 FR 13234...

40 CFR 52.1876 - Control strategy: Nitrogen dioxide.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Control strategy: Nitrogen dioxide. 52...: Nitrogen dioxide. (a) The condition to EPA's approval of the oxides of nitrogen State Implementation Plan... change to the flow control date in the oxides of nitrogen budget trading SIP. (b) [Reserved] [69 FR 13234...

Building a Foundational Model for Credit for Prior Learning. Strategies for Transformative Change

ERIC Educational Resources Information Center

Kamps, A.; Loritz, T.; Schaff, E.; Richie, D.

2016-01-01

"Making the Future: The Wisconsin Strategy," under the leadership of Northeast Wisconsin Technical College (NWTC), received a Round Two U.S. Department of Labor Trade Adjustment Assistance for Community College and Career Training (TAACCCT) grant. The consortium brought together all 16 colleges in the Wisconsin Technical College System…

75 FR 26194 - Notice of Funds Availability: Inviting Applications for the Market Access Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-11

... for the 2011 Market Access Program (MAP). The intended effect of this notice is to solicit... considers whether the applicant provides a clear, long-term agricultural trade strategy and a program... the greatest growth potential. These factors are part of the FAS resource allocation strategy to fund...

75 FR 26191 - Notice of Funds Availability: Inviting Applications for the Foreign Market Development Cooperator...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-11

... intended effect of this notice is to solicit applications from eligible applicants and award funds in... applicant provides a clear, long-term agricultural trade strategy, and a program effectiveness time line... potential. These factors are part of the FAS resource allocation strategy to fund applicants who can...

78 FR 41168 - Self-Regulatory Organizations; NYSE MKT LLC; Notice of Filing of Proposed Rule Change Amending...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-09

... volatility level. Occasionally, certain market activity occurs that makes it difficult to effect these types... combination strategy outside of the currently prevailing market quotes in the individual component series legs...-part strategy trades from occurring out-of-range from the prevailing market quotes in the individual...

Optimal surveillance and eradication of invasive species in heterogeneous landscapes

Treesearch

Rebecca S. Epanchin-Niell; Robert G. Haight; Ludek Berec; John M. Kean; Andrew M. Liebhold

2012-01-01

Cost-effective surveillance strategies are needed for efficient responses to biological invasions and must account for the trade-offs between surveillance effort and management costs. Less surveillance may allow greater population growth and spread prior to detection, thereby increasing the costs of damages and control. In addition, surveillance strategies are usually...

Europa Explorer Operational Scenarios Development

NASA Technical Reports Server (NTRS)

Lock, Robert E.; Pappalardo, Robert T.; Clark, Karla B.

2008-01-01

In 2007, NASA conducted four advanced mission concept studies for outer planets targets: Europa, Ganymede, Titan and Enceladus. The studies were conducted in close cooperation with the planetary science community. Of the four, the Europa Explorer Concept Study focused on refining mission options, science trades and implementation details for a potential flagship mission to Europa in the 2015 timeframe. A science definition team (SDT) was appointed by NASA to guide the study. A JPL-led engineering team worked closely with the science team to address 3 major focus areas: 1) credible cost estimates, 2) rationale and logical discussion of radiation risk and mitigation approaches, and 3) better definition and exploration of science operational scenario trade space. This paper will address the methods and results of the collaborative process used to develop Europa Explorer operations scenarios. Working in concert with the SDT, and in parallel with the SDT's development of a science value matrix, key mission capabilities and constraints were challenged by the science and engineering members of the team. Science goals were advanced and options were considered for observation scenarios. Data collection and return strategies were tested via simulation, and mission performance was estimated and balanced with flight and ground system resources and science priorities. The key to this successful collaboration was a concurrent development environment in which all stakeholders could rapidly assess the feasibility of strategies for their success in the full system context. Issues of science and instrument compatibility, system constraints, and mission opportunities were treated analytically and objectively leading to complementary strategies for observation and data return. Current plans are that this approach, as part of the system engineering process, will continue as the Europa Explorer Concept Study moves toward becoming a development project.

A synthesis of current knowledge on forests and carbon storage in the United States.

PubMed

McKinley, Duncan C; Ryan, Michael G; Birdsey, Richard A; Giardina, Christian P; Harmon, Mark E; Heath, Linda S; Houghton, Richard A; Jackson, Robert B; Morrison, James F; Murray, Brian C; Patakl, Diane E; Skog, Kenneth E

2011-09-01

Using forests to mitigate climate change has gained much interest in science and policy discussions. We examine the evidence for carbon benefits, environmental and monetary costs, risks and trade-offs for a variety of activities in three general strategies: (1) land use change to increase forest area (afforestation) and avoid deforestation; (2) carbon management in existing forests; and (3) the use of wood as biomass energy, in place of other building materials, or in wood products for carbon storage. We found that many strategies can increase forest sector carbon mitigation above the current 162-256 Tg C/yr, and that many strategies have co-benefits such as biodiversity, water, and economic opportunities. Each strategy also has trade-offs, risks, and uncertainties including possible leakage, permanence, disturbances, and climate change effects. Because approximately 60% of the carbon lost through deforestation and harvesting from 1700 to 1935 has not yet been recovered and because some strategies store carbon in forest products or use biomass energy, the biological potential for forest sector carbon mitigation is large. Several studies suggest that using these strategies could offset as much as 10-20% of current U.S. fossil fuel emissions. To obtain such large offsets in the United States would require a combination of afforesting up to one-third of cropland or pastureland, using the equivalent of about one-half of the gross annual forest growth for biomass energy, or implementing more intensive management to increase forest growth on one-third of forestland. Such large offsets would require substantial trade-offs, such as lower agricultural production and non-carbon ecosystem services from forests. The effectiveness of activities could be diluted by negative leakage effects and increasing disturbance regimes. Because forest carbon loss contributes to increasing climate risk and because climate change may impede regeneration following disturbance, avoiding deforestation and promoting regeneration after disturbance should receive high priority as policy considerations. Policies to encourage programs or projects that influence forest carbon sequestration and offset fossil fuel emissions should also consider major items such as leakage, the cyclical nature of forest growth and regrowth, and the extensive demand for and movement of forest products globally, and other greenhouse gas effects, such as methane and nitrous oxide emissions, and recognize other environmental benefits of forests, such as biodiversity, nutrient management, and watershed protection. Activities that contribute to helping forests adapt to the effects of climate change, and which also complement forest carbon storage strategies, would be prudent.

Pathogen evolution under host avoidance plasticity.

PubMed

McLeod, David V; Day, Troy

2015-09-07

Host resistance consists of defences that limit pathogen burden, and can be classified as either adaptations targeting recovery from infection or those focused upon infection avoidance. Conventional theory treats avoidance as a fixed strategy which does not vary from one interaction to the next. However, there is increasing empirical evidence that many avoidance strategies are triggered by external stimuli, and thus should be treated as phenotypically plastic responses. Here, we consider the implications of avoidance plasticity for host-pathogen coevolution. We uncover a number of predictions challenging current theory. First, in the absence of pathogen trade-offs, plasticity can restrain pathogen evolution; moreover, the pathogen exploits conditions in which the host would otherwise invest less in resistance, causing resistance escalation. Second, when transmission trades off with pathogen-induced mortality, plasticity encourages avirulence, resulting in a superior fitness outcome for both host and pathogen. Third, plasticity ensures the sterilizing effect of pathogens has consequences for pathogen evolution. When pathogens castrate hosts, selection forces them to minimize mortality virulence; moreover, when transmission trades off with sterility alone, resistance plasticity is sufficient to prevent pathogens from evolving to fully castrate. © 2015 The Author(s).

Maximum Entropy for the International Division of Labor.

PubMed

Lei, Hongmei; Chen, Ying; Li, Ruiqi; He, Deli; Zhang, Jiang

2015-01-01

As a result of the international division of labor, the trade value distribution on different products substantiated by international trade flows can be regarded as one country's strategy for competition. According to the empirical data of trade flows, countries may spend a large fraction of export values on ubiquitous and competitive products. Meanwhile, countries may also diversify their exports share on different types of products to reduce the risk. In this paper, we report that the export share distribution curves can be derived by maximizing the entropy of shares on different products under the product's complexity constraint once the international market structure (the country-product bipartite network) is given. Therefore, a maximum entropy model provides a good fit to empirical data. The empirical data is consistent with maximum entropy subject to a constraint on the expected value of the product complexity for each country. One country's strategy is mainly determined by the types of products this country can export. In addition, our model is able to fit the empirical export share distribution curves of nearly every country very well by tuning only one parameter.

Maximum Entropy for the International Division of Labor

PubMed Central

Lei, Hongmei; Chen, Ying; Li, Ruiqi; He, Deli; Zhang, Jiang

2015-01-01

As a result of the international division of labor, the trade value distribution on different products substantiated by international trade flows can be regarded as one country’s strategy for competition. According to the empirical data of trade flows, countries may spend a large fraction of export values on ubiquitous and competitive products. Meanwhile, countries may also diversify their exports share on different types of products to reduce the risk. In this paper, we report that the export share distribution curves can be derived by maximizing the entropy of shares on different products under the product’s complexity constraint once the international market structure (the country-product bipartite network) is given. Therefore, a maximum entropy model provides a good fit to empirical data. The empirical data is consistent with maximum entropy subject to a constraint on the expected value of the product complexity for each country. One country’s strategy is mainly determined by the types of products this country can export. In addition, our model is able to fit the empirical export share distribution curves of nearly every country very well by tuning only one parameter. PMID:26172052

Alleviating the water scarcity in the North China Plain: the role of virtual water and real water transfer

NASA Astrophysics Data System (ADS)

Zhang, Zhuoying; Yang, Hong; Shi, Minjun

2016-04-01

The North China Plain is the most water scarce region in China. Its water security is closely relevant to interregional water movement, which can be realized by real water transfers and/or virtual water transfers. This study investigates the roles of virtual water trade and real water transfer using Interregional Input-Output model. The results show that the region is receiving 19.4 billion m3/year of virtual water from the interregional trade, while exporting 16.4 billion m3/year of virtual water in the international trade. In balance, the region has a net virtual water gain of 3 billion m3/year from outside. Its virtual water inflow is dominated by agricultural products from other provinces, totalling 16.6 billion m3/year, whilst its virtual water export is dominated by manufacturing sectors to other countries, totalling 11.7 billion m3/year. Both virtual water import and real water transfer from South to North Water Diversion Project are important water supplements for the region. The results of this study provide useful scientific references for the establishment of combating strategies to deal with the water scarcity in the future.

Evolution of acuteness in pathogen metapopulations: conflicts between “classical” and invasion-persistence trade-offs

PubMed Central

Shrestha, Sourya; Bjørnstad, Ottar N.; King, Aaron A.

2014-01-01

Classical life-history theory predicts that acute, immunizing pathogens should maximize between-host transmission. When such pathogens induce violent epidemic outbreaks, however, a pathogen’s short-term advantage at invasion may come at the expense of its ability to persist in the population over the long term. Here, we seek to understand how the classical and invasion-persistence trade-offs interact to shape pathogen life-history evolution as a function of the size and structure of the host population. We develop an individual-based infection model at three distinct levels of organization: within an individual host, among hosts within a local population, and among local populations within a metapopulation. We find a continuum of evolutionarily stable pathogen strategies. At one end of the spectrum—in large well-mixed populations—pathogens evolve to greater acuteness to maximize between-host transmission: the classical trade-off theory applies in this regime. At the other end of the spectrum—when the host population is broken into many small patches—selection favors less acute pathogens, which persist longer within a patch and thereby achieve enhanced between-patch transmission: the invasion-persistence tradeoff dominates in this regime. Between these extremes, we explore the effects of the size and structure of the host population in determining pathogen strategy. In general, pathogen strategies respond to evolutionary pressures arising at both scales. PMID:25214895

From cigarette smuggling to illicit tobacco trade.

PubMed

Joossens, Luk; Raw, Martin

2012-03-01

Tax policy is considered the most effective strategy to reduce tobacco consumption and prevalence. Tax avoidance and tax evasion therefore undermine the effectiveness of tax policies and result in less revenue for governments, cheaper prices for smokers and increased tobacco use. Tobacco smuggling and illicit tobacco trade have probably always existed, since tobacco's introduction as a valuable product from the New World, but the nature of the trade has changed. This article clarifies definitions, reviews the key issues related to illicit trade, describes the different ways taxes are circumvented and looks at the size of the problem, its changing nature and its causes. The difficulties of data collection and research are discussed. Finally, we look at the policy options to combat illicit trade and the negotiations for a WHO Framework Convention on Tobacco Control (FCTC) protocol on illicit tobacco trade. Twenty years ago the main type of illicit trade was large-scale cigarette smuggling of well known cigarette brands. A change occurred as some major international tobacco companies in Europe and the Americas reviewed their export practices due to tax regulations, investigations and lawsuits by the authorities. Other types of illicit trade emerged such as illegal manufacturing, including counterfeiting and the emergence of new cigarette brands, produced in a rather open manner at well known locations, which are only or mainly intended for the illegal market of another country. The global scope and multifaceted nature of the illicit tobacco trade requires a coordinated international response, so a strong protocol to the FCTC is essential. The illicit tobacco trade is a global problem which needs a global solution.

Evolutionary behaviour, trade-offs and cyclic and chaotic population dynamics.

PubMed

Hoyle, Andy; Bowers, Roger G; White, Andy

2011-05-01

Many studies of the evolution of life-history traits assume that the underlying population dynamical attractor is stable point equilibrium. However, evolutionary outcomes can change significantly in different circumstances. We present an analysis based on adaptive dynamics of a discrete-time demographic model involving a trade-off whose shape is also an important determinant of evolutionary behaviour. We derive an explicit expression for the fitness in the cyclic region and consequently present an adaptive dynamic analysis which is algebraic. We do this fully in the region of 2-cycles and (using a symbolic package) almost fully for 4-cycles. Simulations illustrate and verify our results. With equilibrium population dynamics, trade-offs with accelerating costs produce a continuously stable strategy (CSS) whereas trade-offs with decelerating costs produce a non-ES repellor. The transition to 2-cycles produces a discontinuous change: the appearance of an intermediate region in which branching points occur. The size of this region decreases as we move through the region of 2-cycles. There is a further discontinuous fall in the size of the branching region during the transition to 4-cycles. We extend our results numerically and with simulations to higher-period cycles and chaos. Simulations show that chaotic population dynamics can evolve from equilibrium and vice-versa.

Putting all your eggs in one basket: life-history strategies, bet hedging, and diversification.

PubMed

White, Andrew Edward; Li, Yexin Jessica; Griskevicius, Vladas; Neuberg, Steven L; Kenrick, Douglas T

2013-05-01

Diversification of resources is a strategy found everywhere from the level of microorganisms to that of giant Wall Street investment firms. We examine the functional nature of diversification using life-history theory-a framework for understanding how organisms navigate resource-allocation trade-offs. This framework suggests that diversification may be adaptive or maladaptive depending on one's life-history strategy and that these differences should be observed under conditions of threat. In three studies, we found that cues of mortality threat interact with one index of life-history strategy, childhood socioeconomic status (SES), to affect diversification. Among those from low-SES backgrounds, mortality threat increased preferences for diversification. However, among those from high-SES backgrounds, mortality threat had the opposite effect, inclining people to put all their eggs in one basket. The same interaction pattern emerged with a potential biomarker of life-history strategy, oxidative stress. These findings highlight when, and for whom, different diversification strategies can be advantageous.

Two retailer-supplier supply chain models with default risk under trade credit policy.

PubMed

Wu, Chengfeng; Zhao, Qiuhong

2016-01-01

The purpose of the paper is to formulate two uncooperative replenishment models with demand and default risk which are the functions of the trade credit period, i.e., a Nash equilibrium model and a supplier-Stackelberg model. Firstly, we present the optimal results of decentralized decision and centralized decision without trade credit. Secondly, we derive the existence and uniqueness conditions of the optimal solutions under the two games, respectively. Moreover, we present a set of theorems and corollary to determine the optimal solutions. Finally, we provide an example and sensitivity analysis to illustrate the proposed strategy and optimal solutions. Sensitivity analysis reveals that the total profits of supply chain under the two games both are better than the results under the centralized decision only if the optimal trade credit period isn't too short. It also reveals that the size of trade credit period, demand, retailer's profit and supplier's profit have strong relationship with the increasing demand coefficient, wholesale price, default risk coefficient and production cost. The major contribution of the paper is that we comprehensively compare between the results of decentralized decision and centralized decision without trade credit, Nash equilibrium and supplier-Stackelberg models with trade credit, and obtain some interesting managerial insights and practical implications.

Is diversification in male reproductive traits driven by evolutionary trade-offs between weapons and nuptial gifts?

PubMed Central

Liu, Xingyue; Hayashi, Fumio; Lavine, Laura C.; Yang, Ding

2015-01-01

Many male animals have evolved exaggerated traits that they use in combat with rival males to gain access to females and secure their reproductive success. But some male animals invest in nuptial gifts that gains them access to females. Both these reproductive strategies are costly in that resources are needed to produce the weapon or nuptial gift. In closely related species where both weapons and nuptial gifts are present, little is known about the potential evolutionary trade-off faced by males that have these traits. In this study, we use dobsonflies (order Megaloptera, family Corydalidae, subfamily Corydalinae) to examine the presence and absence of enlarged male weapons versus nuptial gifts within and among species. Many dobsonfly species are sexually dimorphic, and males possess extremely enlarged mandibles that they use in battles, whereas in other species, males produce large nuptial gifts that increase female fecundity. In our study, we show that male accessory gland size strongly correlates with nuptial gift size and that when male weapons are large, nuptial gifts are small and vice versa. We mapped weapons and nuptial gifts onto a phylogeny we constructed of 57 species of dobsonflies. Our among-species comparison shows that large nuptial gift production evolved in many species of dobsonfly but is absent from those with exaggerated weapons. This pattern supports the potential explanation that the trade-off in resource allocation between weapons and nuptial gifts is important in driving the diversity of male mating strategies seen in the dobsonflies, whereas reduced male–male competition in the species producing large spermatophores could be an alternative explanation on their loss of male weapons. Our results shed new light on the evolutionary interplay of multiple sexually selected traits in animals. PMID:25925103

When the management of nurse absenteeism becomes a cause of absenteeism: a study based on a comparison of two health care facilities.

PubMed

Damart, Sébastien; Kletz, Frédéric

2016-01-01

The study aims to explore perceptions of the causes of nurse absenteeism. Nurse absenteeism is rising in many countries. However, there is little evidence as to how strategies adopted in order to cushion the effects of absenteeism on workload influence absenteeism itself. The study used a 'qualitative' method based on cognitive mapping techniques in order to represent perceptions about absenteeism graphically. The study was conducted in two health-care facilities with a sample of 55 interviewees. Absenteeism is due in part to strategies adopted in order to cushion the effects of absenteeism on organisations. Furthermore, the strategies are self-legitimising. The more they are used, the more they are regarded as normal and useful. A plan to reduce absenteeism among nurses must explicitly take into account the strategies used to cushion its impact. To cushion the effects of absenteeism among caregivers, managers must make trade-offs that take into account, for example, the workload or disruption linked to the substitution of personnel. © 2014 John Wiley & Sons Ltd.

A Systematic Study of Sustainable Development Goal (SDG) Interactions

NASA Astrophysics Data System (ADS)

Pradhan, Prajal; Costa, Luís.; Rybski, Diego; Lucht, Wolfgang; Kropp, Jürgen P.

2017-11-01

Sustainable development goals (SDGs) have set the 2030 agenda to transform our world by tackling multiple challenges humankind is facing to ensure well-being, economic prosperity, and environmental protection. In contrast to conventional development agendas focusing on a restricted set of dimensions, the SDGs provide a holistic and multidimensional view on development. Hence, interactions among the SDGs may cause diverging results. To analyze the SDG interactions we systematize the identification of synergies and trade-offs using official SDG indicator data for 227 countries. A significant positive correlation between a pair of SDG indicators is classified as a synergy while a significant negative correlation is classified as a trade-off. We rank synergies and trade-offs between SDGs pairs on global and country scales in order to identify the most frequent SDG interactions. For a given SDG, positive correlations between indicator pairs were found to outweigh the negative ones in most countries. Among SDGs the positive and negative correlations between indicator pairs allowed for the identification of particular global patterns. SDG 1 (No poverty) has synergetic relationship with most of the other goals, whereas SDG 12 (Responsible consumption and production) is the goal most commonly associated with trade-offs. The attainment of the SDG agenda will greatly depend on whether the identified synergies among the goals can be leveraged. In addition, the highlighted trade-offs, which constitute obstacles in achieving the SDGs, need to be negotiated and made structurally nonobstructive by deeper changes in the current strategies.

Ecology shapes the evolutionary trade-off between predator avoidance and defence in coral reef butterflyfishes.

PubMed

Hodge, Jennifer R; Alim, Chidera; Bertrand, Nick G; Lee, Wesley; Price, Samantha A; Tran, Binh; Wainwright, Peter C

2018-07-01

Antipredator defensive traits are thought to trade-off evolutionarily with traits that facilitate predator avoidance. However, complexity and scale have precluded tests of this prediction in many groups, including fishes. Using a macroevolutionary approach, we test this prediction in butterflyfishes, an iconic group of coral reef inhabitants with diverse social behaviours, foraging strategies and antipredator adaptations. We find that several antipredator traits have evolved adaptively, dependent primarily on foraging strategy. We identify a previously unrecognised axis of diversity in butterflyfishes where species with robust morphological defences have riskier foraging strategies and lack sociality, while species with reduced morphological defences feed in familiar territories, have adaptations for quick escapes and benefit from the vigilance provided by sociality. Furthermore, we find evidence for the constrained evolution of fin spines among species that graze solely on corals, highlighting the importance of corals, as both prey and structural refuge, in shaping fish morphology. © 2018 John Wiley & Sons Ltd/CNRS.

Anti-tobacco control industry strategies in Turkey.

PubMed

Keklik, Seda; Gultekin-Karakas, Derya

2018-02-26

Transnational tobacco companies (TTCs) penetrated the Turkish cigarette market due to trade and investment liberalization in the post-1980 period and eventually secured full control. Despite tobacco control policies put in place in reaction to accelerating consumption, TTCs reinforced their market power through a variety of strategies. This paper explores industry strategies that counteract tobacco control policies in Turkey. The study employs both qualitative and quantitative analyses to explore industry strategies in Turkey. Besides the content analyses of industry and market reports, descriptive analyses were conducted for the sub-periods of 1999-2015. The analyses focus on the market strategies of product innovation, advertisement-promotion, cost management and pricing. Rising sales of low tar, ultra-low tar, slim, super-slim and flavoured cigarettes indicate that product innovation served to sustain consumption. Besides, the tobacco industry, using its strong distribution channels, the Internet, and CSR projects, were found to have promoted smoking indirectly. The industry also rationalized manufacturing facilities and reduced the cost of tobacco, making Turkey a cigarette-manufacturing base. Tobacco manufacturers, moreover, offered cigarettes in different price segments and adjusted net prices both up and down according to price categories and market conditions. In response to the successful effect of shifts in price margins, the market share of mid-priced cigarettes expanded while those within the economy category maintained the highest market share. As a result of pricing strategies, net sales revenues increased. Aside from official cigarette sales, the upward trends in the registered and unregistered sales of cigarette substitutes indicate that the demand-side tobacco control efforts remain inadequate. The Turkish case reveals that the resilience of the tobacco industry vis-à-vis mainstream tobacco control efforts necessitates a new policy perspective. Rising market concentration by TTCs and the global nature of industry strategies require that the highly profitable manufacturing and trade of tobacco products should be discouraged on a basis of international collaboration. To reduce and eventually eradicate tobacco consumption, supply-side tobacco control measures are needed along with demand-side policies.

75 FR 82106 - Self-Regulatory Organizations; NYSE Arca, Inc.; Order Granting Approval of Proposed Rule Change...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-29

... Listing and Trading of Shares of the WisdomTree Managed Futures Strategy Fund December 22, 2010. I... WisdomTree Managed Futures Strategy Fund (``Fund'') of the WisdomTree Trust (``Trust'') under NYSE Arca... fund. WisdomTree Asset Management, Inc. (``Adviser'') is the investment adviser to the Fund. WisdomTree...

The role of fecundity and reproductive effort in defining life history strategies of North American freshwater mussels

Treesearch

Wendell R. Haag

2013-01-01

Selection is expected to optimize reproductive investment resulting in characteristic trade-offs among traits such as brood size, offspring size, somatic maintenance, and lifespan; relative patterns of energy allocation to these functions are important in defining life-history strategies. Freshwater mussels are a diverse and imperiled component of aquatic ecosystems,...

Effective Strategy Formation Models for Inventory Management under the Conditions of Uncertainty

ERIC Educational Resources Information Center

Kosorukov, Oleg Anatolyevich; Sviridova, Olga Alexandrovna

2015-01-01

The article deals with the problem of modeling the commodity flows management of a trading company under the conditions of uncertain demand and long supply. The Author presents an analysis of modifications of diversified inventory management system with random demand, for which one can find the optimal inventory control strategies, including those…

75 FR 81689 - Self-Regulatory Organizations; Notice of Filing of Proposed Rule Change by NASDAQ OMX PHLX LLC To...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-28

... closely tailor their investment and risk management strategies and decisions. Furthermore, the Exchange... powerful tool for hedging a market sector, and that various strategies that the investor put into play were... to provide investors with additional short term option classes for investment, trading, and risk...

76 FR 64142 - Self-Regulatory Organizations; The NASDAQ Stock Market LLC; Notice of Filing of Proposed Rule...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-17

... closely tailor their investment and risk management strategies and decisions. Furthermore, the Exchange... position on the Exchange.\\11\\ \\10\\ The risk of not being able to fulfill a particular leg of a strategy or... investment, trading, and risk management purposes. 2. Statutory Basis The Exchange believes that its proposal...

77 FR 76121 - Self-Regulatory Organizations; NYSE Arca, Inc.; Notice of Filing of Proposed Rule Change To List...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-26

... well as other factors that influence exchange rates such as flows, market technical trends, and... Foreign Currency Strategy Exchange-Traded Fund Under NYSE Arca Equities Rule 8.600 December 19, 2012... following under NYSE Arca Equities Rule 8.600 (``Managed Fund Shares''): PIMCO Foreign Currency Strategy...

77 FR 9281 - Self-Regulatory Organizations; NYSE Arca, Inc.; Notice of Filing of Proposed Rule Change Relating...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-16

... and Trading of the PIMCO Global Advantage Inflation-Linked Bond Strategy Fund Under NYSE Arca Equities...''): PIMCO Global Advantage Inflation-Linked Bond Strategy Fund. The text of the proposed rule change is... Shares \\3\\ (``Shares'') under NYSE Arca Equities Rule 8.600: PIMCO Global Advantage Inflation-Linked Bond...

Building clinical and organizational resilience to reconcile safety threats, tensions and trade-offs: insights from theory and evidence.

PubMed

Jeffs, Lianne; Tregunno, Deborah; MacMillan, Kathleen; Espin, Sherry

2009-01-01

Healthcare delivery settings are complex adaptive and tightly coupled, interrelated systems. Within the larger healthcare system, a key subsystem is the "clinical microsystem" level. It is at this level that clinicians are faced with high levels of uncertainty in their daily work - uncertainty that impacts the quality and safety of care that patients receive. The first aim of this paper is to enhance healthcare leaders' understanding of what is currently known about safety threats and strategies to manage the inherent tensions and trade-offs that occur in everyday practice. The second aim is to inform strategies that build clinical and organizational resilience through a multi-level framework derived from the collective theoretical and empirical work. Together, this information can strengthen safety practices throughout healthcare organizations.

An algorithm for testing the efficient market hypothesis.

PubMed

Boboc, Ioana-Andreea; Dinică, Mihai-Cristian

2013-01-01

The objective of this research is to examine the efficiency of EUR/USD market through the application of a trading system. The system uses a genetic algorithm based on technical analysis indicators such as Exponential Moving Average (EMA), Moving Average Convergence Divergence (MACD), Relative Strength Index (RSI) and Filter that gives buying and selling recommendations to investors. The algorithm optimizes the strategies by dynamically searching for parameters that improve profitability in the training period. The best sets of rules are then applied on the testing period. The results show inconsistency in finding a set of trading rules that performs well in both periods. Strategies that achieve very good returns in the training period show difficulty in returning positive results in the testing period, this being consistent with the efficient market hypothesis (EMH).

An Algorithm for Testing the Efficient Market Hypothesis

PubMed Central

Boboc, Ioana-Andreea; Dinică, Mihai-Cristian

2013-01-01

The objective of this research is to examine the efficiency of EUR/USD market through the application of a trading system. The system uses a genetic algorithm based on technical analysis indicators such as Exponential Moving Average (EMA), Moving Average Convergence Divergence (MACD), Relative Strength Index (RSI) and Filter that gives buying and selling recommendations to investors. The algorithm optimizes the strategies by dynamically searching for parameters that improve profitability in the training period. The best sets of rules are then applied on the testing period. The results show inconsistency in finding a set of trading rules that performs well in both periods. Strategies that achieve very good returns in the training period show difficulty in returning positive results in the testing period, this being consistent with the efficient market hypothesis (EMH). PMID:24205148

McMurdo Consolidated Airfields Study: Phase I, Basis of Design

DTIC Science & Technology

2013-01-01

contents of this report are not to be used for advertising , publication, or promotional purposes. Citation of trade names does not constitute an official...interplay of aircraft movement, maintenance, and environmental conditions may allow devel- opment of successful working strategies to maintain runway...Buenos Aires, Argentina, 9−12 August. Bonin, J. H and E. O. Teichmann. 1949. Investigation of solar energy for ice melting. Armour Research

Active Removal of Large Debris: Electrical Propulsion Capabilities

NASA Astrophysics Data System (ADS)

Billot Soccodato, Carole; Lorand, Anthony; Perrin, Veronique; Couzin, Patrice; FontdecabaBaig, Jordi

2013-08-01

The risk for current operational spacecraft or future market induced by large space debris, dead satellites or rocket bodies, in Low Earth Orbit has been identified several years ago. Many potential solutions and architectures are traded with a main objective of reducing cost per debris. Based on cost consideration, specially driven by launch cost, solutions constructed on multi debris capture capacities seem to be much affordable The recent technologic evolutions in electric propulsion and solar power generation can be used to combine high potential vehicles for debris removal. The present paper reports the first results of a study funded by CNES that addresses full electric solutions for large debris removal. Some analysis are currently in progress as the study will end in August. It compares the efficiency of in-orbit Active Removal of typical debris using electric propulsion The electric engine performances used in this analysis are demonstrated through a 2012/2013 PPS 5000 on-ground tests campaign. The traded missions are based on a launch in LEO, the possible vehicle architectures with capture means or contact less, the selection of deorbiting or reorbiting strategy. For contact less strategy, the ion-beam shepherd effect towards the debris problematic will be addressed. Vehicle architecture and performance of the overall system will be stated, showing the adequacy and the limits of each solution.

Optimal strategies for electric energy contract decision making

NASA Astrophysics Data System (ADS)

Song, Haili

2000-10-01

The power industry restructuring in various countries in recent years has created an environment where trading of electric energy is conducted in a market environment. In such an environment, electric power companies compete for the market share through spot and bilateral markets. Being profit driven, electric power companies need to make decisions on spot market bidding, contract evaluation, and risk management. New methods and software tools are required to meet these upcoming needs. In this research, bidding strategy and contract pricing are studied from a market participant's viewpoint; new methods are developed to guide a market participant in spot and bilateral market operation. A supplier's spot market bidding decision is studied. Stochastic optimization is formulated to calculate a supplier's optimal bids in a single time period. This decision making problem is also formulated as a Markov Decision Process. All the competitors are represented by their bidding parameters with corresponding probabilities. A systematic method is developed to calculate transition probabilities and rewards. The optimal strategy is calculated to maximize the expected reward over a planning horizon. Besides the spot market, a power producer can also trade in the bilateral markets. Bidding strategies in a bilateral market are studied with game theory techniques. Necessary and sufficient conditions of Nash Equilibrium (NE) bidding strategy are derived based on the generators' cost and the loads' willingness to pay. The study shows that in any NE, market efficiency is achieved. Furthermore, all Nash equilibria are revenue equivalent for the generators. The pricing of "Flexible" contracts, which allow delivery flexibility over a period of time with a fixed total amount of electricity to be delivered, is analyzed based on the no-arbitrage pricing principle. The proposed algorithm calculates the price based on the optimality condition of the stochastic optimization formulation. Simulation examples illustrate the tradeoffs between prices and scheduling flexibility. Spot bidding and contract pricing are not independent decision processes. The interaction between spot bidding and contract evaluation is demonstrated with game theory equilibrium model and market simulation results. It leads to the conclusion that a market participant's contract decision making needs to be further investigated as an integrated optimization formulation.

Interparameter trade-off quantification and reduction in isotropic-elastic full-waveform inversion: synthetic experiments and Hussar land data set application

NASA Astrophysics Data System (ADS)

Pan, Wenyong; Geng, Yu; Innanen, Kristopher A.

2018-05-01

The problem of inverting for multiple physical parameters in the subsurface using seismic full-waveform inversion (FWI) is complicated by interparameter trade-off arising from inherent ambiguities between different physical parameters. Parameter resolution is often characterized using scattering radiation patterns, but these neglect some important aspects of interparameter trade-off. More general analysis and mitigation of interparameter trade-off in isotropic-elastic FWI is possible through judiciously chosen multiparameter Hessian matrix-vector products. We show that products of multiparameter Hessian off-diagonal blocks with model perturbation vectors, referred to as interparameter contamination kernels, are central to the approach. We apply the multiparameter Hessian to various vectors designed to provide information regarding the strengths and characteristics of interparameter contamination, both locally and within the whole volume. With numerical experiments, we observe that S-wave velocity perturbations introduce strong contaminations into density and phase-reversed contaminations into P-wave velocity, but themselves experience only limited contaminations from other parameters. Based on these findings, we introduce a novel strategy to mitigate the influence of interparameter trade-off with approximate contamination kernels. Furthermore, we recommend that the local spatial and interparameter trade-off of the inverted models be quantified using extended multiparameter point spread functions (EMPSFs) obtained with pre-conditioned conjugate-gradient algorithm. Compared to traditional point spread functions, the EMPSFs appear to provide more accurate measurements for resolution analysis, by de-blurring the estimations, scaling magnitudes and mitigating interparameter contamination. Approximate eigenvalue volumes constructed with stochastic probing approach are proposed to evaluate the resolution of the inverted models within the whole model. With a synthetic Marmousi model example and a land seismic field data set from Hussar, Alberta, Canada, we confirm that the new inversion strategy suppresses the interparameter contamination effectively and provides more reliable density estimations in isotropic-elastic FWI as compared to standard simultaneous inversion approach.

Pricing of swing options: A Monte Carlo simulation approach

NASA Astrophysics Data System (ADS)

Leow, Kai-Siong

We study the problem of pricing swing options, a class of multiple early exercise options that are traded in energy market, particularly in the electricity and natural gas markets. These contracts permit the option holder to periodically exercise the right to trade a variable amount of energy with a counterparty, subject to local volumetric constraints. In addition, the total amount of energy traded from settlement to expiration with the counterparty is restricted by a global volumetric constraint. Violation of this global volumetric constraint is allowed but would lead to penalty settled at expiration. The pricing problem is formulated as a stochastic optimal control problem in discrete time and state space. We present a stochastic dynamic programming algorithm which is based on piecewise linear concave approximation of value functions. This algorithm yields the value of the swing option under the assumption that the optimal exercise policy is applied by the option holder. We present a proof of an almost sure convergence that the algorithm generates the optimal exercise strategy as the number of iterations approaches to infinity. Finally, we provide a numerical example for pricing a natural gas swing call option.

A health impact assessment of California's proposed cap-and-trade regulations.

PubMed

Richardson, Maxwell J; English, Paul; Rudolph, Linda

2012-09-01

To identify unintended health effects of California's controversial cap-and-trade regulations and establish health-promoting policy recommendations, we performed a health impact assessment. We used literature reviews, public data, and local health surveys to qualitatively assess potential health risks and benefits related to changes in employment and income, energy costs, effects of emission offset projects, and cobenefits from the allocation of program revenue. We examined case studies from various communities to find existing social, economic, and environmental health conditions. We found that policy implementation will minimally impact job creation (< 0.1% change) and that health effects from job sector shifts are unlikely. Fuel prices may increase (0%-11%), and minor negative health effects could accrue for some low-income households. Offset projects would likely benefit environmental health, but more research is needed. Allocating some program revenue for climate change adaptation and mitigation would have substantial health benefits. Health impact assessment is a useful tool for health agencies to engage in policy discussions that typically fall outside public health. Our results can inform emission reduction strategies and cap-and-trade policy at the federal level.

Development of an Intellectual Property Strategy: Research Notes to Support Department of Defense Programs

DTIC Science & Technology

2014-09-01

shredding material when no longer needed [ USDA 2014]. 2.4.2 Terms of Trade Secret Ownership A trade secret owner is the person or entity “in whom or...of the DoD’s licensing rights in non-federal works is governed by the DFARS. According to information from CENDI (Commerce, Energy, NASA , Defense...Professionals. March 2014. https://acc.dau.mil/CommunityBrowser.aspx?id=431675 [ USDA 2014] U.S. Department of Agriculture. Proprietary Information

Breaking the Code for Operational Planners: A Comparative Analysis of National Security Strategies Since the End of the Cold War

DTIC Science & Technology

2007-04-04

their continual complaints to their own British brethren have also been ignored: They too have been deaf to the voice of justice and of consanguinity ...nations would be more likely to support free trade and democracy, that nations with growing economies and good trade relationships would be more likely to...interests such as a stable Europe, integrating Russia into the world market, strong relationships with allies, and access to space. The chapter

Chimpanzees (Pan troglodytes) flexibly adjust their behaviour in order to maximize payoffs, not to conform to majorities.

PubMed

Van Leeuwen, Edwin J C; Cronin, Katherine A; Schütte, Sebastian; Call, Josep; Haun, Daniel B M

2013-01-01

Chimpanzees have been shown to be adept learners, both individually and socially. Yet, sometimes their conservative nature seems to hamper the flexible adoption of superior alternatives, even to the extent that they persist in using entirely ineffective strategies. In this study, we investigated chimpanzees' behavioural flexibility in two different conditions under which social animals have been predicted to abandon personal preferences and adopt alternative strategies: i) under influence of majority demonstrations (i.e. conformity), and ii) in the presence of superior reward contingencies (i.e. maximizing payoffs). Unlike previous nonhuman primate studies, this study disentangled the concept of conformity from the tendency to maintain one's first-learned strategy. Studying captive (n=16) and semi-wild (n=12) chimpanzees in two complementary exchange paradigms, we found that chimpanzees did not abandon their behaviour in order to match the majority, but instead remained faithful to their first-learned strategy (Study 1a and 1b). However, the chimpanzees' fidelity to their first-learned strategy was overridden by an experimental upgrade of the profitability of the alternative strategy (Study 2). We interpret our observations in terms of chimpanzees' relative weighing of behavioural options as a function of situation-specific trade-offs. More specifically, contrary to previous findings, chimpanzees in our study abandoned their familiar behaviour to maximize payoffs, but not to conform to a majority.

Gaps in Border Controls Are Related to Quarantine Alien Insect Invasions in Europe

PubMed Central

Bacon, Steven James; Bacher, Sven; Aebi, Alexandre

2012-01-01

Alien insects are increasingly being dispersed around the world through international trade, causing a multitude of negative environmental impacts and billions of dollars in economic losses annually. Border controls form the last line of defense against invasions, whereby inspectors aim to intercept and stop consignments that are contaminated with harmful alien insects. In Europe, member states depend on one another to prevent insect introductions by operating a first point of entry rule – controlling goods only when they initially enter the continent. However, ensuring consistency between border control points is difficult because there exists no optimal inspection strategy. For the first time, we developed a method to quantify the volume of agricultural trade that should be inspected for quarantine insects at border control points in Europe, based on global agricultural trade of over 100 million distinct origin-commodity-species-destination pathways. This metric was then used to evaluate the performance of existing border controls, as measured by border interception results in Europe between 2003 and 2007. Alarmingly, we found significant gaps between the trade pathways that should be inspected and actual number of interceptions. Moreover, many of the most likely introduction pathways yielded none or very few insect interceptions, because regular interceptions are only made on only a narrow range of pathways. European countries with gaps in border controls have been invaded by higher numbers of quarantine alien insect species, indicating the importance of proper inspections to prevent insect invasions. Equipped with an optimal inspection strategy based on the underlying risks of trade, authorities globally will be able to implement more effective and consistent border controls. PMID:23112835

Combating the illegal trade in African elephant ivory with DNA forensics.

PubMed

Wasser, Samuel K; Joseph Clark, William; Drori, Ofir; Stephen Kisamo, Emily; Mailand, Celia; Mutayoba, Benezeth; Stephens, Matthew

2008-08-01

International wildlife crime is burgeoning in this climate of global trade. We contend that the most effective way to contain this illegal trade is to determine where the wildlife is being removed. This allows authorities to direct law enforcement to poaching hot spots, potentially stops trade before the wildlife is actually killed, prevents countries from denying their poaching problems at home, and thwarts trade before it enters into an increasingly complex web of international criminal activity. Forensic tools have been limited in their ability to determine product origin because the information they can provide typically begins only at the point of shipment. DNA assignment analyses can determine product origin, but its use has been limited by the inability to assign samples to locations where reference samples do not exist. We applied new DNA assignment methods that can determine the geographic origin(s) of wildlife products from anywhere within its range. We used these methods to examine the geographic origin(s) of 2 strings of seizures involving large volumes of elephant ivory, 1 string seized in Singapore and Malawi and the other in Hong Kong and Cameroon. These ivory traffickers may comprise 2 of the largest poaching rings in Africa. In both cases all ivory seized in the string had common origins, which indicates that crime syndicates are targeting specific populations for intense exploitation. This result contradicts the dominant belief that dealers are using a decentralized plan of procuring ivory stocks as they became available across Africa. Large quantities of ivory were then moved, in multiple shipments, through an intermediate country prior to shipment to Asia, as a risk-reduction strategy that distances the dealer from the poaching locale. These smuggling strategies could not have been detected by forensic information, which typically begins only at the shipping source.

Engine-start Control Strategy of P2 Parallel Hybrid Electric Vehicle

NASA Astrophysics Data System (ADS)

Xiangyang, Xu; Siqi, Zhao; Peng, Dong

2017-12-01

A smooth and fast engine-start process is important to parallel hybrid electric vehicles with an electric motor mounted in front of the transmission. However, there are some challenges during the engine-start control. Firstly, the electric motor must simultaneously provide a stable driving torque to ensure the drivability and a compensative torque to drag the engine before ignition. Secondly, engine-start time is a trade-off control objective because both fast start and smooth start have to be considered. To solve these problems, this paper first analyzed the resistance of the engine start process, and established a physic model in MATLAB/Simulink. Then a model-based coordinated control strategy among engine, motor and clutch was developed. Two basic control strategy during fast start and smooth start process were studied. Simulation results showed that the control objectives were realized by applying given control strategies, which can meet different requirement from the driver.

The Beneficial Role of Random Strategies in Social and Financial Systems

NASA Astrophysics Data System (ADS)

Biondo, Alessio Emanuele; Pluchino, Alessandro; Rapisarda, Andrea

2013-05-01

In this paper we focus on the beneficial role of random strategies in social sciences by means of simple mathematical and computational models. We briefly review recent results obtained by two of us in previous contributions for the case of the Peter principle and the efficiency of a Parliament. Then, we develop a new application of random strategies to the case of financial trading and discuss in detail our findings about forecasts of markets dynamics.

Are fish immune systems really affected by parasites? an immunoecological study of common carp (Cyprinus carpio)

PubMed Central

2011-01-01

Background The basic function of the immune system is to protect an organism against infection in order to minimize the fitness costs of being infected. According to life-history theory, energy resources are in a trade-off between the costly demands of immunity and other physiological demands. Concerning fish, both physiology and immunity are influenced by seasonal changes (i.e. temporal variation) associated to the changes of abiotic factors (such as primarily water temperature) and interactions with pathogens and parasites. In this study, we investigated the potential associations between the physiology and immunocompetence of common carp (Cyprinus carpio) collected during five different periods of a given year. Our sampling included the periods with temporal variability and thus, it presented a different level in exposure to parasites. We analyzed which of two factors, seasonality or parasitism, had the strongest impact on changes in fish physiology and immunity. Results We found that seasonal changes play a key role in affecting the analyzed measurements of physiology, immunity and parasitism. The correlation analysis revealed the relationships between the measures of overall host physiology, immunity and parasite load when temporal variability effect was removed. When analyzing separately parasite groups with different life-strategies, we found that fish with a worse condition status were infected more by monogeneans, representing the most abundant parasite group. The high infection by cestodes seems to activate the phagocytes. A weak relationship was found between spleen size and abundance of trematodes when taking into account seasonal changes. Conclusions Even if no direct trade-off between the measures of host immunity and physiology was confirmed when taking into account the seasonality, it seems that seasonal variability affects host immunity and physiology through energy allocation in a trade-off between life important functions, especially reproduction and fish condition. Host immunity measures were not found to be in a trade-off with the investigated physiological traits or functions, but we confirmed the immunosuppressive role of 11-ketotestosterone on fish immunity measured by complement activity. We suggest that the different parasite life-strategies influence different aspects of host physiology and activate the different immunity pathways. PMID:21708010

A trait-based trade-off between growth and mortality: evidence from 15 tropical tree species using size-specific relative growth rates

PubMed Central

Philipson, Christopher D; Dent, Daisy H; O’Brien, Michael J; Chamagne, Juliette; Dzulkifli, Dzaeman; Nilus, Reuben; Philips, Sam; Reynolds, Glen; Saner, Philippe; Hector, Andy

2014-01-01

A life-history trade-off between low mortality in the dark and rapid growth in the light is one of the most widely accepted mechanisms underlying plant ecological strategies in tropical forests. Differences in plant functional traits are thought to underlie these distinct ecological strategies; however, very few studies have shown relationships between functional traits and demographic rates within a functional group. We present 8 years of growth and mortality data from saplings of 15 species of Dipterocarpaceae planted into logged-over forest in Malaysian Borneo, and the relationships between these demographic rates and four key functional traits: wood density, specific leaf area (SLA), seed mass, and leaf C:N ratio. Species-specific differences in growth rates were separated from seedling size effects by fitting nonlinear mixed-effects models, to repeated measurements taken on individuals at multiple time points. Mortality data were analyzed using binary logistic regressions in a mixed-effects models framework. Growth increased and mortality decreased with increasing light availability. Species differed in both their growth and mortality rates, yet there was little evidence for a statistical interaction between species and light for either response. There was a positive relationship between growth rate and the predicted probability of mortality regardless of light environment, suggesting that this relationship may be driven by a general trade-off between traits that maximize growth and traits that minimize mortality, rather than through differential species responses to light. Our results indicate that wood density is an important trait that indicates both the ability of species to grow and resistance to mortality, but no other trait was correlated with either growth or mortality. Therefore, the growth mortality trade-off among species of dipterocarp appears to be general in being independent of species crossovers in performance in different light environments. PMID:25478157

An evolutionarily stable strategy and the critical point of hog futures trading entities based on replicator dynamic theory: 2006–2015 data for China’s 22 provinces

PubMed Central

Pang, Jinbo; Deng, Lingfei

2017-01-01

Although frequent fluctuations in domestic hog prices seriously affect the stability and robustness of the hog supply chain, hog futures (an effective hedging instrument) have not been listed in China. To better understand hog futures market hedging, it is important to study the steady state of intersubjective bidding. This paper uses evolutionary game theory to construct a game model between hedgers and speculators in the hog futures market, and replicator dynamic equations are then used to obtain the steady state between the two trading entities. The results show that the steady state is one in which hedgers adopt a “buy” strategy and speculators adopt a “do not speculate” strategy, but this type of extreme steady state is not easily realized. Thus, to explore the rational proportion of hedgers and speculators in the evolutionary stabilization strategy, bidding processes were simulated using weekly average hog prices from 2006 to 2015, such that the conditions under which hedgers and speculators achieve a steady state could be analyzed. This task was performed to achieve the stability critical point, and we show that only when the value of λ is satisfied and the conditions of hog futures price changes and futures price are satisfied can hedgers and speculators achieve a rational proportion and a stable hog futures market. This market can thus provide a valuable reference for the development of the Chinese hog futures market and the formulation and guidance of relevant departmental policies. PMID:28241024

An evolutionarily stable strategy and the critical point of hog futures trading entities based on replicator dynamic theory: 2006-2015 data for China's 22 provinces.

PubMed

Pang, Jinbo; Deng, Lingfei; Wang, Gangyi

2017-01-01

Although frequent fluctuations in domestic hog prices seriously affect the stability and robustness of the hog supply chain, hog futures (an effective hedging instrument) have not been listed in China. To better understand hog futures market hedging, it is important to study the steady state of intersubjective bidding. This paper uses evolutionary game theory to construct a game model between hedgers and speculators in the hog futures market, and replicator dynamic equations are then used to obtain the steady state between the two trading entities. The results show that the steady state is one in which hedgers adopt a "buy" strategy and speculators adopt a "do not speculate" strategy, but this type of extreme steady state is not easily realized. Thus, to explore the rational proportion of hedgers and speculators in the evolutionary stabilization strategy, bidding processes were simulated using weekly average hog prices from 2006 to 2015, such that the conditions under which hedgers and speculators achieve a steady state could be analyzed. This task was performed to achieve the stability critical point, and we show that only when the value of λ is satisfied and the conditions of hog futures price changes and futures price are satisfied can hedgers and speculators achieve a rational proportion and a stable hog futures market. This market can thus provide a valuable reference for the development of the Chinese hog futures market and the formulation and guidance of relevant departmental policies.

Compliance by Design: Influence of Acceleration Trade-offs on CO2 Emissions and Costs of Fuel Economy and Greenhouse Gas Regulations.

PubMed

Whitefoot, Kate S; Fowlie, Meredith L; Skerlos, Steven J

2017-09-19

The ability of automakers to improve the fuel economy of vehicles using engineering design modifications that compromise other performance attributes, such as acceleration, is not currently considered when setting fuel economy and greenhouse-gas emission standards for passenger cars and light trucks. We examine the role of these design trade-offs by simulating automaker responses to recently reformed vehicle standards with and without the ability to adjust acceleration performance. Results indicate that acceleration trade-offs can be important in two respects: (1) they can reduce the compliance costs of the standards, and (2) they can significantly reduce emissions associated with a particular level of the standards by mitigating incentives to shift sales toward larger vehicles and light trucks relative to passenger cars. We contrast simulation-based results with observed changes in vehicle attributes under the reformed standards. We find evidence that is consistent with firms using acceleration trade-offs to achieve compliance. Taken together, our analysis suggests that acceleration trade-offs play a role in automaker compliance strategies with potentially large implications for both compliance costs and emissions.

Virtual water trade of agricultural products: A new perspective to explore the Belt and Road.

PubMed

Zhang, Yu; Zhang, Jin-He; Tian, Qing; Liu, Ze-Hua; Zhang, Hong-Lei

2018-05-01

The Belt and Road is an initiative of cooperation and development that was proposed by China. Moreover, most of the spanning countries faced water shortages and agriculture consumed a lot of water. Virtual water links water, food and trade and is an effective tool to ease water shortages. Therefore, this paper aims to understand the Belt and Road from the new perspective of virtual water trade of agricultural products. We considered agricultural products trade from 2001 to 2015. On the whole, the results indicated that China was in virtual water trade surplus with the countries along the Belt and Road. However, in terms of each country, >40 spanning countries were in virtual water trade surplus with China and eased water shortages. Russia had the largest net imported virtual water from China. Furthermore, the proportion of the grey water footprint that China exported to the spanning countries was much higher than that imported, no matter from the whole or different geographical regions. Moreover, more than half of the countries' virtual water trade with China conformed to the virtual water strategy, which helped to ease water crises. Furthermore, the products that they exported to China were mainly advantageous products that each spanning countries have. Virtual water trade is a new perspective to explore the Belt and Road. Agricultural products trade with China definitely benefits both the countries along the Belt and Road and China from the perspective of virtual water. The findings are beneficial for the water management of the countries along the Belt and Road and China, alleviating water shortages, encouraging the rational allocation of water resources in the various departments. They can provide references for optimizing trade structures as well. Copyright © 2017 Elsevier B.V. All rights reserved.

Insight into tradeoff between wood decay and parasitism from the genome of a fungal forest pathogen

Treesearch

Ake Olson; Andrea Aerts; Fred Asiegbu; Lassaad Belbahri; Ourdia Bouzid; Anders Broberg; Bjorn Canback; Pedro M. Coutinho; Dan Cullen; Kerstin Dalman; Giuliana Deflorio; Linda T.A. van Diepen; Christophe Dunand; Sebastien Duplessis; Mikael Durling; Paolo Gonthier; Jane Grimwood; Carl Gunnar Fossdal; David Hansson; Bernard Henrissat; Ari Hietala; Kajsa Himmelsrand; Dirk Hoffmeister; Nils Hogberg; Timothy Y. James; Magnus Karlsson; Annegret Kohler; Ursula Kues; Yong-Hwan Lee; Yao-Cheng Lin; Marten Lind; Erika Lindquist; Vincent Lombard; Susan Lucas; Karl Lunden; Emmanuelle Morin; Claude Murat; Jongsun Park; Tommaso Raffaello; Pierre Rouze; Asaf Salamov; Jeremy Schmutz; Halvor Solheim; Jerry Stahlberg; Heriberto Velez; Ronald P. deVries; Ad Wiebenga; Steve Woodward; Igor Yakovlev; Matteo Garbelotto; Francis Martin; Igor V. Grigoriev; Jan Stenlid

2012-01-01

• Parasitism and saprotrophic wood decay are two fungal strategies fundamental for succession and nutrient cycling in forest ecosystems. An opportunity to assess the trade-off between these strategies is provided by the forest pathogen and wood decayer Heterobasidion annosum sensu lato. • We report the annotated genome sequence and transcript...

78 FR 15093 - Self-Regulatory Organizations; BOX Options Exchange LLC; Notice of Filing of Proposed Rule Change...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-08

... \\3\\ on BOX Market LLC (``BOX''), the options trading facility of the Exchange. In particular, the... (3.00) and for the purpose of executing a particular investment strategy.'' See proposed Rule 7240(a...'' is defined as the ``the best net bid and offer price for a Complex Order Strategy based on the NBBO...

A reaction-diffusion model for market fluctuations - A relation between price change and traded volumes

NASA Astrophysics Data System (ADS)

Yuvan, Steven; Bier, Martin

2018-02-01

Two decades ago Bak et al. (1997) [3] proposed a reaction-diffusion model to describe market fluctuations. In the model buyers and sellers diffuse from opposite ends of a 1D interval that represents a price range. Trades occur when buyers and sellers meet. We show analytically and numerically that the model well reproduces the square-root relation between traded volumes and price changes that is observed in real-life markets. The result is remarkable as this relation has commonly been explained in terms of more elaborate trader strategies. We furthermore explain why the square-root relation is robust under model modifications and we show how real-life bond market data exhibit the square-root relation.

Current and potential trade in horticultural products irradiated for phytosanitary purposes

NASA Astrophysics Data System (ADS)

Bustos-Griffin, Emilia; Hallman, Guy J.; Griffin, Robert L.

2012-08-01

The current status of trade in horticultural products irradiated for phytosanitary purposes is examined, including trends, strengths and weaknesses. A strategy is proposed to take advantage of the best future opportunities for increasing trade in irradiated horticultural products by identifying best possibilities for expanding both the number and volume of commodities for irradiation and then applying appropriate business criteria in a general analysis of the commodities, commercial scenarios, and geographic regions where the greatest potential exists for expansion. The results show that fresh fruits such as mango, papaya, citrus, grapes, and vegetables such as tomatoes, onions, asparagus, garlic, and peppers from Asia and the Americas show the greatest potential. Substantial opportunities for additional growth exist, especially as regulatory conditions become more favorable.

[Competition and prices in the Mexican pharmaceutical market].

PubMed

Molina-Salazar, Raúl E; González-Marín, Eloy; Carbajal-de Nova, Carolina

2008-01-01

The forms of market competition define prices. The pharmaceutical market contains submarkets with different levels of competition; on the one hand are the innovating products with patents, and on the other, generic products with or without trade names. Innovating medicines generally have monopolistic prices, but when the patents expire prices drop because of competition from therapeutic alternatives. The trade name makes it easier to maintain monopolistic prices. In Mexico, medicine prices in the private market are high--according to aggregated estimates and prices for specific medicines--which reflect the limitations of pharmaceutical market competition and the power of the trade name. The public segment enjoys competitive prices using the WHO strategy for essential medicines on the basis of the Essential List.

Successful technical trading agents using genetic programming.

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

Othling, Andrew S.; Kelly, John A.; Pryor, Richard J.

2004-10-01

Genetic programming (GP) has proved to be a highly versatile and useful tool for identifying relationships in data for which a more precise theoretical construct is unavailable. In this project, we use a GP search to develop trading strategies for agent based economic models. These strategies use stock prices and technical indicators, such as the moving average convergence/divergence and various exponentially weighted moving averages, to generate buy and sell signals. We analyze the effect of complexity constraints on the strategies as well as the relative performance of various indicators. We also present innovations in the classical genetic programming algorithm thatmore » appear to improve convergence for this problem. Technical strategies developed by our GP algorithm can be used to control the behavior of agents in economic simulation packages, such as ASPEN-D, adding variety to the current market fundamentals approach. The exploitation of arbitrage opportunities by technical analysts may help increase the efficiency of the simulated stock market, as it does in the real world. By improving the behavior of simulated stock markets, we can better estimate the effects of shocks to the economy due to terrorism or natural disasters.« less

'Preparing ourselves to become an international organization': Thailand Tobacco Monopoly's regional and global strategies.

PubMed

MacKenzie, Ross; Ross, Hana; Lee, Kelley

2017-03-01

The Thailand Tobacco Monopoly (TTM) controlled the country's tobacco industry from its formation in the 1940s, until the government dropped restrictions on imported cigarettes in the late 1980s in response to pressure from the United States. The TTM has since competed with transnational tobacco companies (TTCs) in a semi-monopoly market in which TTCs have steadily increased their market share. Coupled with a decline in national smoking prevalence, the result of Thailand's stringent tobacco control agenda, the TTM now accounts for a diminishing share of a contracting market. In response, the monopoly has looked to regional trade liberalisation, and proximity to markets with some of the world's highest smoking rates to expand its operations. Expansion strategies have gone largely unrealised however, and the TTM effectively remains a domestic operation. Using TTM publications, market and trade reports, industry publications, tobacco industry documents and other resources, this paper analyses TTM expansion strategies, and the limited extent to which they have been achieved. This inability to expand its operations has left the monopoly potentially vulnerable to global strategies of its transnational competitors. This article is part of the special issue 'The Emergence of Asian Tobacco Companies: Implications for Global Health Governance'.

Improving food security empowerment in Indonesia- Timor Leste border

NASA Astrophysics Data System (ADS)

Dewi, G. D. P.; Yustikaningrum, R. V.

2018-03-01

Post Referendum 1999, Indonesia and Timor Leste have a strategic challenge to provide food consistently around the border. This research intended to discover an appropriate strategy to tackle fragility of food security in the land border of Indonesia-Timor Leste, to improve collaborative actions between parties, as well as, opportunity to actualize food cross-border trading between local farmers and factories. For the result, there are two approaches will be applied. First, the empowerment term refers to the strategy of empowerment in strengthening the capability and capacity of human capital as one of the determinant factors of the resilience and self-sufficiency achievement. Second, the gender approach looks at the women and men build confidence, resilience, and independence which one of them through an educational intervention that enable the local people to manage food chain. Atambua is a region count as relatively as high poverty, poor human capital, weak quality and competitiveness of agriculture products, livestock and fishery, SMEs, and infrastructure. Thus, field study research is applied to find the actual and strategic effort aim to lead the achievement of food security and to engage Atambua over food trade to Timor Leste.

Perceived Cost and Intrinsic Motor Variability Modulate the Speed-Accuracy Trade-Off

PubMed Central

Bertucco, Matteo; Bhanpuri, Nasir H.; Sanger, Terence D.

2015-01-01

Fitts’ Law describes the speed-accuracy trade-off of human movements, and it is an elegant strategy that compensates for random and uncontrollable noise in the motor system. The control strategy during targeted movements may also take into account the rewards or costs of any outcomes that may occur. The aim of this study was to test the hypothesis that movement time in Fitts’ Law emerges not only from the accuracy constraints of the task, but also depends on the perceived cost of error for missing the targets. Subjects were asked to touch targets on an iPad® screen with different costs for missed targets. We manipulated the probability of error by comparing children with dystonia (who are characterized by increased intrinsic motor variability) to typically developing children. The results show a strong effect of the cost of error on the Fitts’ Law relationship characterized by an increase in movement time as cost increased. In addition, we observed a greater sensitivity to increased cost for children with dystonia, and this behavior appears to minimize the average cost. The findings support a proposed mathematical model that explains how movement time in a Fitts-like task is related to perceived risk. PMID:26447874

Trade-off between benefit and harm is crucial in health screening recommendations. Part II: evidence summaries.

PubMed

Silvestre, Maria Asuncion A; Dans, Leonila F; Dans, Antonio L

2011-03-01

Evidence on the effectiveness of health screening strategies may be direct (i.e., studies on screening vs. no screening) or indirect (i.e., studies that separately evaluate the screening test[s], the confirmatory test, or the treatment). Critical trade-offs in the balance between harm and benefit for many screening strategies mandate that advocates of health screening adhere to the ethical precepts of nonmaleficence, autonomy, confidentiality, and equity. In our first article, we pointed out five prerequisites to justifying a health screening program: (1) the burden of illness should be high, (2) the screening and confirmatory tests should be accurate, (3) early treatment (or prevention) must be more effective than late treatment, (4) the tests and the treatment(s) must be safe, and (5) the cost of the screening strategy must be commensurate with the potential benefit. As can be gleaned from these criteria, recommendations on screening must be tailored to specific populations. Recommendations in one country, no matter how authoritative, cannot be generalized to apply to all other countries. Although accuracy, effectiveness, and safety data may be global (criteria 2-4), burden of illness and efficiency (criteria 1 and 5) will always vary from country to country. Rather than review various national guidelines, in this last article of our two-part series, we present evidence summaries to illustrate health screening. Our examples were selected to address special issues related to four situations-screening for cancer, risk factors for disease, genetic disorders, and infectious diseases. Copyright © 2011 Elsevier Inc. All rights reserved.

Rendezvous and Docking Strategy for Crewed Segment of the Asteroid Redirect Mission

NASA Technical Reports Server (NTRS)

Hinkel, Heather D.; Cryan, Scott P.; D'Souza, Christopher; Dannemiller, David P.; Brazzel, Jack P.; Condon, Gerald L.; Othon, William L.; Williams, Jacob

2014-01-01

This paper will describe the overall rendezvous, proximity operations and docking (RPOD) strategy in support of the Asteroid Redirect Crewed Mission (ARCM), as part of the Asteroid Redirect Mission (ARM). The focus of the paper is on the crewed mission phase of ARM, starting with the establishment of Orion in the Distant Retrograde Orbit (DRO) and ending with docking to the Asteroid Redirect Vechicle (ARV). The paper will detail the sequence of maneuvers required to execute the rendezvous and proximity operations mission phases along with the on-board navigation strategies, including the final approach phase. The trajectories to be considered will include target vehicles in a DRO. The paper will also discuss the sensor requirements for rendezvous and docking and the various trade studies associated with the final sensor selection. Building on the sensor requirements and trade studies, the paper will include a candidate sensor concept of operations, which will drive the selection of the sensor suite; concurrently, it will be driven by higher level requirements on the system, such as crew timeline constraints and vehicle consummables. This paper will address how many of the seemingly competing requirements will have to be addressed to create a complete system and system design. The objective is to determine a sensor suite and trajectories that enable Orion to successfully rendezvous and dock with a target vehicle in trans lunar space. Finally, the paper will report on the status of a NASA action to look for synergy within RPOD, across the crewed and robotic asteroid missions.

Understanding the legal trade of cattle and camels and the derived risk of Rift Valley Fever introduction into and transmission within Egypt

PubMed Central

Chevalier, Veronique; Busquets, Núria; Calistri, Paolo; Casal, Jordi; Attia, Mohamed; Elbassal, Rehab; Hosni, Heba; Farrag, Hatem; Hassan, Noura; Tawfik, Rasha; Abd Elkader, Sohair; Bayomy, Shahin

2018-01-01

Rift Valley Fever (RVF) is a mosquito-borne zoonosis, which may cause significant losses for the livestock sector and have serious public health implications. Egypt has been repeatedly affected by RVF epidemics, mainly associated to the importation of animals from sub-Saharan countries, where the disease is endemic. The objective of our study was the improvement of the surveillance and control strategies implemented in Egypt. In order to do that, first we evaluated the legal trade of live animals into and within Egypt. Then, we assessed the risk of Rift Valley Fever virus (RVFV) transmission within the country using a multi-criteria evaluation approach. Finally, we combined the animal trade and the risk of RVFV transmission data to identify those areas and periods in which the introduction of RVFV is more likely. Our results indicate that the main risk of RVFV introduction is posed by the continuous flow of large number of camels coming from Sudan. The risk of RVFV transmission by vectors is restricted to the areas surrounding the Nile river, and does not vary significantly throughout the year. Imported camels are taken to quarantines, where the risk of RVFV transmission by vectors is generally low. Then, they are taken to animal markets or slaughterhouses, many located in populated areas, where the risk of RVFV transmission to animals or humans is much higher. The measures currently implemented (quarantines, vaccination or testing) seem to have a limited effect in reducing the risk of RVFV introduction, and therefore other (risk-based) surveillance strategies are proposed. PMID:29351273

The air, carbon, water synergies and trade-offs in China's natural gas industry

NASA Astrophysics Data System (ADS)

Qin, Y.; Mauzerall, D. L.; Höglund-Isaksson, L.; Wagner, F.; Byers, E.

2017-12-01

Both energy production and consumption can simultaneously affect regional air quality, local water stress, and the global climate. Identifying air, carbon and water impacts of various energy sources and end-uses is important in determining the relative merits of various energy policies. Here, we examine the air-carbon-water interdependencies of China's six major natural gas source choices (domestic conventional natural gas, domestic coal-based synthetic natural gas (SNG), domestic shale gas, imported liquefied natural gas, imported Russian pipeline gas, and imported Central Asian pipeline gas) and three end-use coal-to-gas deployment strategies (with substitution strategies that focus in turn on air quality, carbon, and water) in 2020. On the supply side, we find that gas sources other than SNG offer national air-carbon-water co-benefits. However, we find striking air-carbon/water trade-offs for SNG at the national scale. Moreover, the use of SNG significantly increases water demand and carbon emissions in regions already suffering from the most severe water stress and the highest per capita carbon footprint. On the end-use side, gas substitution for coal can result in enormous variations in air quality, carbon, and water impacts, with notable air-carbon synergies but air-water trade-offs. Our study finds that, except for SNG, end-use choices generally have a much larger influence on air quality, carbon emissions and water use than do gas source choices. Simultaneous consideration of air, carbon, and water impacts is necessary in designing both beneficial energy development and deployment policies.

Interactive dose shaping part 2: proof of concept study for six prostate patients

NASA Astrophysics Data System (ADS)

Kamerling, Cornelis Ph; Ziegenhein, Peter; Sterzing, Florian; Oelfke, Uwe

2016-03-01

Recently we introduced interactive dose shaping (IDS) as a new IMRT planning strategy. This planning concept is based on a hierarchical sequence of local dose modification and recovery operations. The purpose of this work is to provide a feasibility study for the IDS planning strategy based on a small set of six prostate patients. The IDS planning paradigm aims to perform interactive local dose adaptations of an IMRT plan without compromising already established valuable dose features in real-time. Various IDS tools were developed in our in-house treatment planning software Dynaplan and were utilized to create IMRT treatment plans for six patients with an adeno-carcinoma of the prostate. The sequenced IDS treatment plans were compared to conventionally optimized clinically approved plans (9 beams, co-planar). For each patient, several IDS plans were created, with different trade-offs between organ sparing and target coverage. The reference dose distributions were imported into Dynaplan. For each patient, the IDS treatment plan with a similar or better trade-off between target coverage and OAR sparing was selected for plan evaluation, guided by a physician. For this initial study we were able to generate treatment plans for prostate geometries in 15-45 min. Individual local dose adaptations could be performed in less than one second. The average differences compared to the reference plans were for the mean dose: 0.0 Gy (boost) and 1.2 Gy (PTV), for {{D}98%}:-1.1 Gy and for {{D}2%}:1.1 Gy (both target volumes). The dose-volume quality indicators were well below the Quantec constraints. However, we also observed limitations of our currently implemented approach. Most prominent was an increase of the non-tumor integral dose by 16.4% on average, demonstrating that further developments of our planning strategy are required.

Problem-solving and learning in Carib grackles: individuals show a consistent speed-accuracy trade-off.

PubMed

Ducatez, S; Audet, J N; Lefebvre, L

2015-03-01

The generation and maintenance of within-population variation in cognitive abilities remain poorly understood. Recent theories propose that this variation might reflect the existence of consistent cognitive strategies distributed along a slow-fast continuum influenced by shyness. The slow-fast continuum might be reflected in the well-known speed-accuracy trade-off, where animals cannot simultaneously maximise the speed and the accuracy with which they perform a task. We test this idea on 49 wild-caught Carib grackles (Quiscalus lugubris), a tame opportunistic generalist Icterid bird in Barbados. Grackles that are fast at solving novel problems involving obstacle removal to reach visible food perform consistently over two different tasks, spend more time per trial attending to both tasks, and are those that show more shyness in a pretest. However, they are also the individuals that make more errors in a colour discrimination task requiring no new motor act. Our data reconcile some of the mixed positive and negative correlations reported in the comparative literature on cognitive tasks, suggesting that a speed-accuracy trade-off could lead to negative correlations between tasks favouring speed and tasks favouring accuracy, but still reveal consistent strategies based on stable individual differences.

Advancing Public Health on the Changing Global Trade and Investment Agenda Comment on "The Trans-Pacific Partnership: Is It Everything We Feared for Health?"

PubMed

Thow, Anne Marie; Gleeson, Deborah

2016-09-28

Concerns regarding the Trans-Pacific Partnership (TPP) have raised awareness about the negative public health impacts of trade and investment agreements. In the past decade, we have learned much about the implications of trade agreements for public health: reduced equity in access to health services; increased flows of unhealthy commodities; limits on access to medicines; and constrained policy space for health. Getting health on the trade agenda continues to prove challenging, despite some progress in moving towards policy coherence. Recent changes in trade and investment agendas highlight an opportunity for public health researchers and practitioners to engage in highly politicized debates about how future economic policy can protect and support equitable public health outcomes. To fulfil this opportunity, public health attention now needs to turn to strengthening policy coherence between trade and health, and identifying how solutions can be implemented. Key strategies include research agendas that address politics and power, and capacity building for both trade and health officials. © 2017 The Author(s); Published by Kerman University of Medical Sciences. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

The effect of trade books on the environmental literacy of 11th and 12th graders in aquatic science

NASA Astrophysics Data System (ADS)

Lewis, Ann S.

The purpose of this study was to compare the environmental literacy of 11th and 12th graders who participated in an eighteen-week environmental education program using trade books versus 11 th- and 12th-graders who participated in an eighteen-week, traditional environmental education program without the use of trade books. This study was conducted using a quasi-experimental research technique. Four high school aquatic science classes at two suburban high schools were used in the research. One teacher at each high school taught one control class and one experimental class of aquatic science. In the experimental classes, four trade books were read to the classes during the eighteen-week semester. These four books were selected by the participating teachers before the semester began. The books used were A Home by the Sea, Sea Otter Rescue, There's a Hair in My Dirt, and The Missing Gator of Gumbo Limbo. The instrument used to measure environmental literacy was the Children's Environmental Attitude and Knowledge Scale. This test was given at the beginning of the semester and at the end of the semester. The scores at the end of the semester were analyzed by 2 x 2 mixed model ANOVA with the teacher as the random effect and the condition (trade books) as the fixed effect. The statistical analysis of this study showed that the students in the experimental classes did not score higher than the control classes on the Children's Environmental Attitude and Knowledge Scale or on a subset of "water" questions. Several limitations were placed on this research. These limitations included the following: (1) a small number of classes and a small number of teachers, (2) change from the original plan of using environmental science classes to aquatic science classes, (3) possible indifference of the students, and (4) restrictive teaching strategies of the teachers.

A detailed heterogeneous agent model for a single asset financial market with trading via an order book.

PubMed

Mota Navarro, Roberto; Larralde, Hernán

2017-01-01

We present an agent based model of a single asset financial market that is capable of replicating most of the non-trivial statistical properties observed in real financial markets, generically referred to as stylized facts. In our model agents employ strategies inspired on those used in real markets, and a realistic trade mechanism based on a double auction order book. We study the role of the distinct types of trader on the return statistics: specifically, correlation properties (or lack thereof), volatility clustering, heavy tails, and the degree to which the distribution can be described by a log-normal. Further, by introducing the practice of "profit taking", our model is also capable of replicating the stylized fact related to an asymmetry in the distribution of losses and gains.

There is No Free Lunch: Tradeoffs in the Utility of Learned Knowledge

NASA Technical Reports Server (NTRS)

Kedar, Smadar T.; McKusick, Kathleen B.

1992-01-01

With the recent introduction of learning in integrated systems, there is a need to measure the utility of learned knowledge for these more complex systems. A difficulty arrises when there are multiple, possibly conflicting, utility metrics to be measured. In this paper, we present schemes which trade off conflicting utility metrics in order to achieve some global performance objectives. In particular, we present a case study of a multi-strategy machine learning system, mutual theory refinement, which refines world models for an integrated reactive system, the Entropy Reduction Engine. We provide experimental results on the utility of learned knowledge in two conflicting metrics - improved accuracy and degraded efficiency. We then demonstrate two ways to trade off these metrics. In each, some learned knowledge is either approximated or dynamically 'forgotten' so as to improve efficiency while degrading accuracy only slightly.

A detailed heterogeneous agent model for a single asset financial market with trading via an order book

PubMed Central

2017-01-01

We present an agent based model of a single asset financial market that is capable of replicating most of the non-trivial statistical properties observed in real financial markets, generically referred to as stylized facts. In our model agents employ strategies inspired on those used in real markets, and a realistic trade mechanism based on a double auction order book. We study the role of the distinct types of trader on the return statistics: specifically, correlation properties (or lack thereof), volatility clustering, heavy tails, and the degree to which the distribution can be described by a log-normal. Further, by introducing the practice of “profit taking”, our model is also capable of replicating the stylized fact related to an asymmetry in the distribution of losses and gains. PMID:28245251

Microscopic understanding of heavy-tailed return distributions in an agent-based model

NASA Astrophysics Data System (ADS)

Schmitt, Thilo A.; Schäfer, Rudi; Münnix, Michael C.; Guhr, Thomas

2012-11-01

The distribution of returns in financial time series exhibits heavy tails. It has been found that gaps between the orders in the order book lead to large price shifts and thereby to these heavy tails. We set up an agent-based model to study this issue and, in particular, how the gaps in the order book emerge. The trading mechanism in our model is based on a double-auction order book. In situations where the order book is densely occupied with limit orders we do not observe fat-tailed distributions. As soon as less liquidity is available, a gap structure forms which leads to return distributions with heavy tails. We show that return distributions with heavy tails are an order-book effect if the available liquidity is constrained. This is largely independent of specific trading strategies.

Nash and integrated solutions in a just-in-time seller-buyer supply chain with buyer's ordering cost reductions

NASA Astrophysics Data System (ADS)

Lou, Kuo-Ren; Wang, Lu

2016-05-01

The seller frequently offers the buyer trade credit to settle the purchase amount. From the seller's prospective, granting trade credit increases not only the opportunity cost (i.e., the interest loss on the buyer's purchase amount during the credit period) but also the default risk (i.e., the rate that the buyer will be unable to pay off his/her debt obligations). On the other hand, granting trade credit increases sales volume and revenue. Consequently, trade credit is an important strategy to increase seller's profitability. In this paper, we assume that the seller uses trade credit and number of shipments in a production run as decision variables to maximise his/her profit, while the buyer determines his/her replenishment cycle time and capital investment as decision variables to reduce his/her ordering cost and achieve his/her maximum profit. We then derive non-cooperative Nash solution and cooperative integrated solution in a just-in-time inventory system, in which granting trade credit increases not only the demand but also the opportunity cost and default risk, and the relationship between the capital investment and the ordering cost reduction is logarithmic. Then, we use a software to solve and compare these two distinct solutions. Finally, we use sensitivity analysis to obtain some managerial insights.

Greenhouse Gas Emission Mitigation And Agriculture, Trade-off Or Win-win Situation: Bioeconomic Farm Modelling In The Sudanian Area of Burkina Faso

NASA Astrophysics Data System (ADS)

Some, T. E.; Barbier, B.

2015-12-01

Climate changes talks regularly underline that developing countries' agriculture could play a stronger role in GHGs mitigation strategies and benefit from the Kyoto Protocol program of subsidies. Scientists explain that agriculture can contribute to carbon mitigation by storing more carbon in the soil through greener cropping systems. In this context, a growing number of research projects have started to investigate how developing countries agriculture can contribute to these objectives. The clean development mechanism (CDM) proposed in the Kyoto protocol is one particular policy instrument that can incite farmers to mitigate the GHG balance towards more sequestration and less emission. Some economists such as Michael Porter think that environmental regulation lead to a win-win outcome, in which case subsidies are not necessary. If it is a trade-off between incomes and the environment, subsidies are required. CDM can be mobilized to support the mitigation strategy. Agriculture implies the use of inputs. Reducing the emission implies the reduction of those inputs which will in turn imply a yield decrease. The study aims to assess whether this measure will imply a trade-off between environmental and economic objectives or a win-win situation. I apply this study to the case of small farmers in Burkina Faso through environmental instruments such as the emissions limits and agroforestry using a bioeconomic model, in which the farmers maximize their utility subject to constraints. The study finds that the limitation of emissions in annual crops production involves a trade-off. by impacting negatively their net cash come. By integrating perennial crops in the farming system, the farmers' utility increases. Around 6,118 kg are sequestrated individually. By computing the value on this carbon balance, farmers' net cash incomes go better. Then practicing agroforestry is a win-win situation, as they reach a higher level of income, and reduce emissions. Policymakers must encourage small farmers to integrate perennial crops in their annual crops system. Most of small farmers are living below the poverty line. Limiting emissions will get worse their life conditions. To reach the emission reduction objective in the annual crops system, subsidies are needed in order to compensate the income lost through the CDM.

Worldwide Emerging Environmental Issues Affecting the U.S. Military. June 2005 Report

DTIC Science & Technology

2005-06-01

Trade and Environment issues that help promote environmental protection and improve enforcement of environmental law; and Expand Partnerships for...in view of the Army’s Strategy for the Environment and the CEC’s Partnerships for Environmental Stewardship strategies. Source: CEC Ministerial...reducing mercury use, emissions, wastes and surplus stockpiles, and participating in partnerships with organizations and countries requesting assistance. If

What Strategy Should Bulgaria Pursue to Track and Disrupt Terror Networks in the Balkans?

DTIC Science & Technology

2014-03-01

important function of law enforcement is to “disrupt terrorist financing that includes by uncovering links between terrorists and organized criminal groups... money laundering , black market activity, and drug trade.”119 C. SUMMARY International terrorism is constantly evolving in its tactics and...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited WHAT STRATEGY SHOULD

76 FR 2174 - Self-Regulatory Organizations; International Securities Exchange, LLC; Notice of Filing and...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-12

... traders additional opportunities and strategies to hedge high priced securities. Currently, Exchange Rule... example if Apple, Inc. (``AAPL'') would trade at $310 \\6\\ with approximately two months remaining until...

40 CFR 52.1876 - Control strategy: Nitrogen dioxide.

Code of Federal Regulations, 2010 CFR

2010-07-01

...: Nitrogen dioxide. (a) The condition to EPA's approval of the oxides of nitrogen State Implementation Plan... change to the flow control date in the oxides of nitrogen budget trading SIP. (b) [Reserved] [69 FR 13234...

A Writer's Bag of Tricks

ERIC Educational Resources Information Center

Rotkow, Debra T.

2005-01-01

This paper describes how a few simple strategies can provide students with a variety of great writing ideas. Some of the ideas presented are: writing workshops, trading book lists, creating journals, writing poetry, and peer topic conferences.

Strategies for sustainable management of renewable resources during environmental change.

PubMed

Lindkvist, Emilie; Ekeberg, Örjan; Norberg, Jon

2017-03-15

As a consequence of global environmental change, management strategies that can deal with unexpected change in resource dynamics are becoming increasingly important. In this paper we undertake a novel approach to studying resource growth problems using a computational form of adaptive management to find optimal strategies for prevalent natural resource management dilemmas. We scrutinize adaptive management, or learning-by-doing, to better understand how to simultaneously manage and learn about a system when its dynamics are unknown. We study important trade-offs in decision-making with respect to choosing optimal actions (harvest efforts) for sustainable management during change. This is operationalized through an artificially intelligent model where we analyze how different trends and fluctuations in growth rates of a renewable resource affect the performance of different management strategies. Our results show that the optimal strategy for managing resources with declining growth is capable of managing resources with fluctuating or increasing growth at a negligible cost, creating in a management strategy that is both efficient and robust towards future unknown changes. To obtain this strategy, adaptive management should strive for: high learning rates to new knowledge, high valuation of future outcomes and modest exploration around what is perceived as the optimal action. © 2017 The Author(s).

Cognitive strategies in the mental rotation task revealed by EEG spectral power.

PubMed

Gardony, Aaron L; Eddy, Marianna D; Brunyé, Tad T; Taylor, Holly A

2017-11-01

The classic mental rotation task (MRT; Shepard & Metzler, 1971) is commonly thought to measure mental rotation, a cognitive process involving covert simulation of motor rotation. Yet much research suggests that the MRT recruits both motor simulation and other analytic cognitive strategies that depend on visuospatial representation and visual working memory (WM). In the present study, we investigated cognitive strategies in the MRT using time-frequency analysis of EEG and independent component analysis. We scrutinized sensorimotor mu (µ) power reduction, associated with motor simulation, parietal alpha (pα) power reduction, associated with visuospatial representation, and frontal midline theta (fmθ) power enhancement, associated with WM maintenance and manipulation. µ power increased concomitant with increasing task difficulty, suggesting reduced use of motor simulation, while pα decreased and fmθ power increased, suggesting heightened use of visuospatial representation processing and WM, respectively. These findings suggest that MRT performance involves flexibly trading off between cognitive strategies, namely a motor simulation-based mental rotation strategy and WM-intensive analytic strategies based on task difficulty. Flexible cognitive strategy use may be a domain-general cognitive principle that underlies aptitude and spatial intelligence in a variety of cognitive domains. We close with discussion of the present study's implications as well as future directions. Published by Elsevier Inc.

Optimal execution with price impact under Cumulative Prospect Theory

NASA Astrophysics Data System (ADS)

Zhao, Jingdong; Zhu, Hongliang; Li, Xindan

2018-01-01

Optimal execution of a stock (or portfolio) has been widely studied in academia and in practice over the past decade, and minimizing transaction costs is a critical point. However, few researchers consider the psychological factors for the traders. What are traders truly concerned with - buying low in the paper accounts or buying lower compared to others? We consider the optimal trading strategies in terms of the price impact and Cumulative Prospect Theory and identify some specific properties. Our analyses indicate that a large proportion of the execution volume is distributed at both ends of the transaction time. But the trader's optimal strategies may not be implemented at the same transaction size and speed in different market environments.

Measurements of Rationality: Individual Differences in Information Processing, the Transitivity of Preferences and Decision Strategies

PubMed Central

Sleboda, Patrycja; Sokolowska, Joanna

2017-01-01

The first goal of this study was to validate the Rational-Experiential Inventory (REI) and the Cognitive Reflection Test (CRT) through checking their relation to the transitivity axiom. The second goal was to test the relation between decision strategies and cognitive style as well as the relation between decision strategies and the transitivity of preferences. The following characteristics of strategies were investigated: requirements for trade-offs, maximization vs. satisficing and option-wise vs. attribute-wise information processing. Respondents were given choices between two multi-attribute options. The options were designed so that the choice indicated which strategy was applied. Both the REI-R and the CRT were found to be good predictors of the transitivity of preferences. Respondents who applied compensatory strategies and the maximization criterion scored highly on the REI-R and in the CRT, whereas those who applied the satisficing rule scored highly on the REI-R but not in the CRT. Attribute-wise information processing was related to low scores in both measurements. Option-wise information processing led to a high transitivity of preferences. PMID:29093695

Measurements of Rationality: Individual Differences in Information Processing, the Transitivity of Preferences and Decision Strategies.

PubMed

Sleboda, Patrycja; Sokolowska, Joanna

2017-01-01

The first goal of this study was to validate the Rational-Experiential Inventory ( REI ) and the Cognitive Reflection Test ( CRT ) through checking their relation to the transitivity axiom. The second goal was to test the relation between decision strategies and cognitive style as well as the relation between decision strategies and the transitivity of preferences. The following characteristics of strategies were investigated: requirements for trade-offs, maximization vs. satisficing and option-wise vs. attribute-wise information processing. Respondents were given choices between two multi-attribute options. The options were designed so that the choice indicated which strategy was applied. Both the REI-R and the CRT were found to be good predictors of the transitivity of preferences. Respondents who applied compensatory strategies and the maximization criterion scored highly on the REI-R and in the CRT , whereas those who applied the satisficing rule scored highly on the REI-R but not in the CRT . Attribute-wise information processing was related to low scores in both measurements. Option-wise information processing led to a high transitivity of preferences.

Minority games, evolving capitals and replicator dynamics

NASA Astrophysics Data System (ADS)

Galla, Tobias; Zhang, Yi-Cheng

2009-11-01

We discuss a simple version of the minority game (MG) in which agents hold only one strategy each, but in which their capitals evolve dynamically according to their success and in which the total trading volume varies in time accordingly. This feature is known to be crucial for MGs to reproduce stylized facts of real market data. The stationary states and phase diagram of the model can be computed, and we show that the ergodicity breaking phase transition common for MGs, and marked by a divergence of the integrated response, is present also in this simplified model. An analogous majority game turns out to be relatively void of interesting features, and the total capital is found to diverge in time. Introducing a restraining force leads to a model akin to the replicator dynamics of evolutionary game theory, and we demonstrate that here a different type of phase transition is observed. Finally we briefly discuss the relation of this model with one strategy per player to more sophisticated minority games with dynamical capitals and several trading strategies per agent.

Invasive reptiles and amphibians.

PubMed

Moutou, F; Pastoret, P P

2010-08-01

Although they are frequently lumped together, reptiles and amphibians belong to two very different zoological groups. Nevertheless, one fact is clear: while numerous reptile and amphibian species on Earth are in decline, others have taken advantage of trade or human movements to become established in new lands, adopting different, and sometimes unusual, strategies. The authors have taken a few examples from these two zoological groups that illustrate the majority of cases. A brief analysis of the causes and effects of their introductions into new areas reveals connections with economic interests, trade in companion animals, medical research and public health.

Implications of the World Trade Organization in combating non-communicable diseases.

PubMed

Mitchell, A; Voon, T

2011-12-01

The World Health Organization (WHO) has proposed a number of strategies to combat non-communicable diseases such as cancers, cardiovascular diseases, chronic respiratory diseases and diabetes by targeting the risk factors of tobacco use, harmful use of alcohol and poor diet. A number of the domestic regulatory responses contemplated by WHO and individual countries have the potential to restrict or distort trade, raising the question of whether they are consistent with the obligations imposed on Members of the World Trade Organization (WTO). This article demonstrates that WTO rules do limit Members' flexibility in implementing public health measures to address these diseases. However, the focus of WTO provisions on preventing discrimination against or between imports and the exceptions incorporated in various WTO agreements leave sufficient scope for Members to design carefully directed measures to achieve genuine public health goals while minimizing negative effects on international trade. Copyright © 2011 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Emergence of trend trading and its effects in minority game

NASA Astrophysics Data System (ADS)

Liu, Xing-Hua; Liang, Xiao-Bei; Wang, Nai-Jing

2006-09-01

In this paper, we extended Minority Game (MG) by equipping agents with both value and trend strategies. In the new model, agents (we call them strong-adaptation agents) can autonomically select to act as trend trader or value trader when they game and learn in system. So the new model not only can reproduce stylized factors but also has the potential to investigate into the process of some problems of securities market. We investigated the dynamics of trend trading and its impacts on securities market based on the new model. Our research found that trend trading is inevitable when strong-adaptation agents make decisions by inductive reasoning. Trend trading (of strong-adaptation agents) is not irrational behavior but shows agent's strong-adaptation intelligence, because strong-adaptation agents can take advantage of the pure value agents when they game together in hybrid system. We also found that strong-adaptation agents do better in real environment. The results of our research are different with those of behavior finance researches.

Evolving dynamics of trading behavior based on coordination game in complex networks

NASA Astrophysics Data System (ADS)

Bian, Yue-tang; Xu, Lu; Li, Jin-sheng

2016-05-01

This work concerns the modeling of evolvement of trading behavior in stock markets. Based on the assumption of the investors' limited rationality, the evolution mechanism of trading behavior is modeled according to the investment strategy of coordination game in network, that investors are prone to imitate their neighbors' activity through comprehensive analysis on the risk dominance degree of certain investment behavior, the network topology of their relationship and its heterogeneity. We investigate by mean-field analysis and extensive simulations the evolution of investors' trading behavior in various typical networks under different risk dominance degree of investment behavior. Our results indicate that the evolution of investors' behavior is affected by the network structure of stock market and the effect of risk dominance degree of investment behavior; the stability of equilibrium states of investors' behavior dynamics is directly related with the risk dominance degree of some behavior; connectivity and heterogeneity of the network plays an important role in the evolution of the investment behavior in stock market.

Impact of the World Trade Organization TRIPS agreement on the pharmaceutical industry in Thailand.

PubMed Central

Supakankunti, S.; Janjaroen, W. S.; Tangphao, O.; Ratanawijitrasin, S.; Kraipornsak, P.; Pradithavanij, P.

2001-01-01

The 1994 World Trade Organization (WTO) Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS) established minimum universal standards in all areas of intellectual property. It is intended to implement these standards globally through a WTO enforcement mechanism. The present article proposes a strategy for alleviating the potentially negative impact of TRIPS in Thailand in relation to the following: purchasers; prescribers and dispensers; producers; products; price control; patent-to-third-party; parallel imports; power of the customer; patentable new drugs; personnel; and prevention policies. The following TRIPS provisions are pertinent to the pharmaceutical industry in Thailand: the limited term of product and process patents; the conditions of protection; and the broad scope for compulsory licensing and enforcement procedures in the national patent system. PMID:11417042

Phylogenetic trait conservatism and the evolution of functional trade-offs in arbuscular mycorrhizal fungi.

PubMed

Powell, Jeff R; Parrent, Jeri L; Hart, Miranda M; Klironomos, John N; Rillig, Matthias C; Maherali, Hafiz

2009-12-07

The diversity of functional and life-history traits of organisms depends on adaptation as well as the legacy of shared ancestry. Although the evolution of traits in macro-organisms is well studied, relatively little is known about character evolution in micro-organisms. Here, we surveyed an ancient and ecologically important group of microbial plant symbionts, the arbuscular mycorrhizal (AM) fungi, and tested hypotheses about the evolution of functional and life-history traits. Variation in the extent of root and soil colonization by AM fungi is constrained to a few nodes basal to the most diverse groups within the phylum, with relatively little variation associated with recent divergences. We found no evidence for a trade-off in biomass allocated to root versus soil colonization in three published glasshouse experiments; rather these traits were positively correlated. Partial support was observed for correlated evolution between fungal colonization strategies and functional benefits of the symbiosis to host plants. The evolution of increased soil colonization was positively correlated with total plant biomass and shoot phosphorus content. Although the effect of AM fungi on infection by root pathogens was phylogenetically conserved, there was no evidence for correlated evolution between the extent of AM fungal root colonization and pathogen infection. Variability in colonization strategies evolved early in the diversification of AM fungi, and we propose that these strategies were influenced by functional interactions with host plants, resulting in an evolutionary stasis resembling trait conservatism.

Distributed Power Allocation for Wireless Sensor Network Localization: A Potential Game Approach.

PubMed

Ke, Mingxing; Li, Ding; Tian, Shiwei; Zhang, Yuli; Tong, Kaixiang; Xu, Yuhua

2018-05-08

The problem of distributed power allocation in wireless sensor network (WSN) localization systems is investigated in this paper, using the game theoretic approach. Existing research focuses on the minimization of the localization errors of individual agent nodes over all anchor nodes subject to power budgets. When the service area and the distribution of target nodes are considered, finding the optimal trade-off between localization accuracy and power consumption is a new critical task. To cope with this issue, we propose a power allocation game where each anchor node minimizes the square position error bound (SPEB) of the service area penalized by its individual power. Meanwhile, it is proven that the power allocation game is an exact potential game which has one pure Nash equilibrium (NE) at least. In addition, we also prove the existence of an ϵ -equilibrium point, which is a refinement of NE and the better response dynamic approach can reach the end solution. Analytical and simulation results demonstrate that: (i) when prior distribution information is available, the proposed strategies have better localization accuracy than the uniform strategies; (ii) when prior distribution information is unknown, the performance of the proposed strategies outperforms power management strategies based on the second-order cone program (SOCP) for particular agent nodes after obtaining the estimated distribution of agent nodes. In addition, proposed strategies also provide an instructional trade-off between power consumption and localization accuracy.

Allocation trade-off under climate warming in experimental amphibian populations

PubMed Central

Gao, Xu; Jin, Changnan; Camargo, Arley

2015-01-01

Climate change could either directly or indirectly cause population declines via altered temperature, rainfall regimes, food availability or phenological responses. However few studies have focused on allocation trade-offs between growth and reproduction under marginal resources, such as food scarce that may be caused by climate warming. Such critical changes may have an unpredicted impact on amphibian life-history parameters and even population dynamics. Here, we report an allocation strategy of adult anuran individuals involving a reproductive stage under experimental warming. Using outdoor mesocosm experiments we simulated a warming scenario likely to occur at the end of this century. We examined the effects of temperature (ambient vs. pre-/post-hibernation warming) and food availability (normal vs. low) on reproduction and growth parameters of pond frogs (Pelophylax nigromaculatus). We found that temperature was the major factor influencing reproductive time of female pond frogs, which showed a significant advancing under post-hibernation warming treatment. While feeding rate was the major factor influencing reproductive status of females, clutch size, and variation of body size for females, showed significant positive correlations between feeding rate and reproductive status, clutch size, or variation of body size. Our results suggested that reproduction and body size of amphibians might be modulated by climate warming or food availability variation. We believe this study provides some new evidence on allocation strategies suggesting that amphibians could adjust their reproductive output to cope with climate warming. PMID:26500832

75 FR 44826 - Self-Regulatory Organizations; NASDAQ OMX BX, Inc.; Notice of Filing and Immediate Effectiveness...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-29

... flexibility and the ability to more closely tailor their investment and risk management strategies and... additional strikes for investment, trading, and risk management purposes. 2. Statutory Basis The Exchange...

Simulation For Task Practice in Technical Training.

ERIC Educational Resources Information Center

Mallory, W. J.

1981-01-01

Describes two programs used by the Ford Motor Company to train manufacturing skilled trades personnel. Programmable Controller Maintenance Training Program for Industrial Technicians and Troubleshooting Strategy Program use simulation and provide improved task performance after training. (JOW)

Complicity in contraband: British American Tobacco and cigarette smuggling in Asia

PubMed Central

Collin, J; LeGresley, E; MacKenzie, R; Lawrence, S; Lee, K

2004-01-01

Objectives: To examine the complicity of British American Tobacco (BAT) in cigarette smuggling in Asia, and to assess the centrality of illicit trade to regional corporate strategy. Methods: Analysis of previously confidential documents from BAT's Guildford depository. An iterative strategy combined searches based on geography, organisational structure, and key personnel, while corporate euphemisms for contraband were identified by triangulation. Results: BAT documents demonstrate the strategic importance of smuggling across global, regional, national, and local levels. Particularly important in Asia, contraband enabled access to closed markets, created pressure for market opening, and was highly profitable. Documents demonstrate BAT's detailed oversight of illicit trade, seeking to reconcile the conflicting demands of control and deniability. Conclusions: BAT documents demonstrate that smuggling has been driven by corporate objectives, indicate national measures by which the problem can be addressed, and highlight the importance of a coordinated global response via WHO's Framework Convention on Tobacco Control. PMID:15564212

Complicity in contraband: British American Tobacco and cigarette smuggling in Asia.

PubMed

Collin, J; Legresley, E; MacKenzie, R; Lawrence, S; Lee, K

2004-12-01

To examine the complicity of British American Tobacco (BAT) in cigarette smuggling in Asia, and to assess the centrality of illicit trade to regional corporate strategy. Analysis of previously confidential documents from BAT's Guildford depository. An iterative strategy combined searches based on geography, organisational structure, and key personnel, while corporate euphemisms for contraband were identified by triangulation. BAT documents demonstrate the strategic importance of smuggling across global, regional, national, and local levels. Particularly important in Asia, contraband enabled access to closed markets, created pressure for market opening, and was highly profitable. Documents demonstrate BAT's detailed oversight of illicit trade, seeking to reconcile the conflicting demands of control and deniability. BAT documents demonstrate that smuggling has been driven by corporate objectives, indicate national measures by which the problem can be addressed, and highlight the importance of a coordinated global response via WHO's Framework Convention on Tobacco Control.

Ownership, financing, and management strategies of the ten largest for-profit nursing home chains in the United States.

PubMed

Harrington, Charlene; Hauser, Clarilee; Olney, Brian; Rosenau, Pauline Vaillancourt

2011-01-01

This study examined the ownership, financing, and management strategies of the 10 largest for-profit nursing home chains in the United States, including the four largest chains purchased by private equity corporations. Descriptive data were collected from Internet searches, company reports, and other sources for the decade 1998-2008. Since 1998, the largest chains have made many changes in their ownership and structure, and some have converted from publicly traded companies to private ownership. This study shows the increasing complexity of corporate nursing home ownership and the lack of public information about ownership and financial status. The chains have used strategies to maximize shareholder and investor value that include increasing Medicare revenues, occupancy rates, and company diversification, establishing multiple layers of corporate ownership, developing real estate investment trusts, and creating limited liability companies. These strategies enhance shareholder and investor profits, reduce corporate taxes, and reduce liability risk. There is a need for greater transparency in ownership and financial reporting and for more government oversight of the largest for-profit chains, including those owned by private equity companies.

Functional Trait Trade-Offs for the Tropical Montane Rain Forest Species Responding to Light from Simulating Experiments

PubMed Central

Mao, Peili; Zang, Runguo; Shao, Hongbo; Yu, Junbao

2014-01-01

Differences among tropical tree species in survival and growth to light play a key role in plant competition and community composition. Two canopy species with contrasting functional traits dominating early and late successional stages, respectively, in a tropical montane rain forest of Hainan Island, China, were selected in a pot experiment under 4 levels of light intensity (full, 50%, 30%, and 10%) in order to explore the adaptive strategies of tropical trees to light conditions. Under each light intensity level, the pioneer species, Endospermum chinense (Euphorbiaceae), had higher relative growth rate (RGR), stem mass ratio (SMR), specific leaf area (SLA), and morphological plasticity while the shade tolerant climax species, Parakmeria lotungensis (Magnoliaceae), had higher root mass ratio (RMR) and leaf mass ratio (LMR). RGR of both species was positively related to SMR and SLA under each light level but was negatively correlated with RMR under lower light (30% and 10% full light). The climax species increased its survival by a conservative resource use strategy through increasing leaf defense and root biomass investment at the expense of growth rate in low light. In contrast, the pioneer increased its growth by an exploitative resource use strategy through increasing leaf photosynthetic capacity and stem biomass investment at the expense of survival under low light. There was a trade-off between growth and survival for species under different light conditions. Our study suggests that tree species in the tropical rainforest adopt different strategies in stands of different successional stages. Species in the earlier successional stages have functional traits more advantageous to grow faster in the high light conditions, whereas species in the late successional stages have traits more favorable to survive in the low light conditions. PMID:25019095

Linked sustainability challenges and trade-offs among fisheries, aquaculture and agriculture.

PubMed

Blanchard, Julia L; Watson, Reg A; Fulton, Elizabeth A; Cottrell, Richard S; Nash, Kirsty L; Bryndum-Buchholz, Andrea; Büchner, Matthias; Carozza, David A; Cheung, William W L; Elliott, Joshua; Davidson, Lindsay N K; Dulvy, Nicholas K; Dunne, John P; Eddy, Tyler D; Galbraith, Eric; Lotze, Heike K; Maury, Olivier; Müller, Christoph; Tittensor, Derek P; Jennings, Simon

2017-09-01

Fisheries and aquaculture make a crucial contribution to global food security, nutrition and livelihoods. However, the UN Sustainable Development Goals separate marine and terrestrial food production sectors and ecosystems. To sustainably meet increasing global demands for fish, the interlinkages among goals within and across fisheries, aquaculture and agriculture sectors must be recognized and addressed along with their changing nature. Here, we assess and highlight development challenges for fisheries-dependent countries based on analyses of interactions and trade-offs between goals focusing on food, biodiversity and climate change. We demonstrate that some countries are likely to face double jeopardies in both fisheries and agriculture sectors under climate change. The strategies to mitigate these risks will be context-dependent, and will need to directly address the trade-offs among Sustainable Development Goals, such as halting biodiversity loss and reducing poverty. Countries with low adaptive capacity but increasing demand for food require greater support and capacity building to transition towards reconciling trade-offs. Necessary actions are context-dependent and include effective governance, improved management and conservation, maximizing societal and environmental benefits from trade, increased equitability of distribution and innovation in food production, including continued development of low input and low impact aquaculture.

Real Time Updating Genetic Network Programming for Adapting to the Change of Stock Prices

NASA Astrophysics Data System (ADS)

Chen, Yan; Mabu, Shingo; Shimada, Kaoru; Hirasawa, Kotaro

The key in stock trading model is to take the right actions for trading at the right time, primarily based on the accurate forecast of future stock trends. Since an effective trading with given information of stock prices needs an intelligent strategy for the decision making, we applied Genetic Network Programming (GNP) to creating a stock trading model. In this paper, we propose a new method called Real Time Updating Genetic Network Programming (RTU-GNP) for adapting to the change of stock prices. There are three important points in this paper: First, the RTU-GNP method makes a stock trading decision considering both the recommendable information of technical indices and the candlestick charts according to the real time stock prices. Second, we combine RTU-GNP with a Sarsa learning algorithm to create the programs efficiently. Also, sub-nodes are introduced in each judgment and processing node to determine appropriate actions (buying/selling) and to select appropriate stock price information depending on the situation. Third, a Real Time Updating system has been firstly introduced in our paper considering the change of the trend of stock prices. The experimental results on the Japanese stock market show that the trading model with the proposed RTU-GNP method outperforms other models without real time updating. We also compared the experimental results using the proposed method with Buy&Hold method to confirm its effectiveness, and it is clarified that the proposed trading model can obtain much higher profits than Buy&Hold method.

International trade in meat: the tip of the pork chop.

PubMed

Galloway, James N; Burke, Marshall; Bradford, G Eric; Naylor, Rosamond; Falcon, Walter; Chapagain, Ashok K; Gaskell, Joanne C; McCullough, Ellen; Mooney, Harold A; Oleson, Kirsten L L; Steinfeld, Henning; Wassenaar, Tom; Smil, Vaclav

2007-12-01

This paper provides an original account of global land, water, and nitrogen use in support of industrialized livestock production and trade, with emphasis on two of the fastest-growing sectors, pork and poultry. Our analysis focuses on trade in feed and animal products, using a new model that calculates the amount of "virtual" nitrogen, water, and land used in production but not embedded in the product. We show how key meat-importing countries, such as Japan, benefit from "virtual" trade in land, water, and nitrogen, and how key meat-exporting countries, such as Brazil, provide these resources without accounting for their true environmental cost. Results show that Japan's pig and chicken meat imports embody the virtual equivalent of 50% of Japan's total arable land, and half of Japan's virtual nitrogen total is lost in the US. Trade links with China are responsible for 15% of the virtual nitrogen left behind in Brazil due to feed and meat exports, and 20% of Brazil's area is used to grow soybean exports. The complexity of trade in meat, feed, water, and nitrogen is illustrated by the dual roles of the US and The Netherlands as both importers and exporters of meat. Mitigation of environmental damage from industrialized livestock production and trade depends on a combination of direct-pricing strategies, regulatory approaches, and use of best management practices. Our analysis indicates that increased water- and nitrogen-use efficiency and land conservation resulting from these measures could significantly reduce resource costs.

Predicting shifting sustainability trade-offs in marine finfish aquaculture under climate change.

PubMed

Sarà, Gianluca; Gouhier, Tarik C; Brigolin, Daniele; Porporato, Erika M D; Mangano, Maria Cristina; Mirto, Simone; Mazzola, Antonio; Pastres, Roberto

2018-05-03

Defining sustainability goals is a crucial but difficult task because it often involves the quantification of multiple interrelated and sometimes conflicting components. This complexity may be exacerbated by climate change, which will increase environmental vulnerability in aquaculture and potentially compromise the ability to meet the needs of a growing human population. Here, we developed an approach to inform sustainable aquaculture by quantifying spatio-temporal shifts in critical trade-offs between environmental costs and benefits using the time to reach the commercial size as a possible proxy of economic implications of aquaculture under climate change. Our results indicate that optimizing aquaculture practices by minimizing impact (this study considers as impact a benthic carbon deposition ≥ 1 g C m -2  day -1 ) will become increasingly difficult under climate change. Moreover, an increasing temperature will produce a poleward shift in sustainability trade-offs. These findings suggest that future sustainable management strategies and plans will need to account for the effects of climate change across scales. Overall, our results highlight the importance of integrating environmental factors in order to sustainably manage critical natural resources under shifting climatic conditions. © 2018 John Wiley & Sons Ltd.

Reviewing the adoption and impact of water markets in the Murray-Darling Basin, Australia

NASA Astrophysics Data System (ADS)

Wheeler, S.; Loch, A.; Zuo, A.; Bjornlund, H.

2014-10-01

Water markets have increasingly been adopted as a reallocation tool around the world as water scarcity intensifies. Water markets were first introduced in Australia in the 1980s, and water entitlement and allocation trade have been increasingly adopted by both private individuals and governments. As well as providing an overview of water policy in Australia since the 1900s, this paper examines the adoption of water trading in the southern Murray-Darling Basin of Australia (the largest hydrologically connected water market in Australia), and investigates the associated social, economic and environmental impacts that have arisen from the implementation of water markets. This study found that up to 86% of irrigators in one state in the southern Murray-Darling Basin had undertaken at least one water market trade by 2010-2011, hence, water market strategies are now a common tool employed by irrigators to assist their farm management. A variety of institutional, policy and informational changes are identified to increase the benefits from water markets in the future. There is no doubt that managing the impact of climate change and water scarcity are intertwined, suggesting that policy, institutional and governance responses should be similarly structured and coordinated.

The 2015 National Security Strategy: Authorities, Changes, Issues for Congress

DTIC Science & Technology

2016-04-05

Strategy: Authorities, Changes, Issues for Congress Congressional Research Service 3  reverse the spread of nuclear and biological weapons and...secure nuclear materials;  advance peace, security, and opportunity in the greater Middle East;  invest in the capacity of strong and capable...and norms on issues ranging from maritime security to trade and human rights.” 6 On Russia, the document says, “... we will continue to impose

‘Preparing ourselves to become an international organization’: Thailand Tobacco Monopoly’s regional and global strategies

PubMed Central

MacKenzie, Ross; Ross, Hana; Lee, Kelley

2017-01-01

ABSTRACT The Thailand Tobacco Monopoly (TTM) controlled the country’s tobacco industry from its formation in the 1940s, until the government dropped restrictions on imported cigarettes in the late 1980s in response to pressure from the United States. The TTM has since competed with transnational tobacco companies (TTCs) in a semi-monopoly market in which TTCs have steadily increased their market share. Coupled with a decline in national smoking prevalence, the result of Thailand’s stringent tobacco control agenda, the TTM now accounts for a diminishing share of a contracting market. In response, the monopoly has looked to regional trade liberalisation, and proximity to markets with some of the world’s highest smoking rates to expand its operations. Expansion strategies have gone largely unrealised however, and the TTM effectively remains a domestic operation. Using TTM publications, market and trade reports, industry publications, tobacco industry documents and other resources, this paper analyses TTM expansion strategies, and the limited extent to which they have been achieved. This inability to expand its operations has left the monopoly potentially vulnerable to global strategies of its transnational competitors. This article is part of the special issue ‘The Emergence of Asian Tobacco Companies: Implications for Global Health Governance’. PMID:28139965

Benefit-risk Evaluation for Diagnostics: A Framework (BED-FRAME).

PubMed

Evans, Scott R; Pennello, Gene; Pantoja-Galicia, Norberto; Jiang, Hongyu; Hujer, Andrea M; Hujer, Kristine M; Manca, Claudia; Hill, Carol; Jacobs, Michael R; Chen, Liang; Patel, Robin; Kreiswirth, Barry N; Bonomo, Robert A

2016-09-15

The medical community needs systematic and pragmatic approaches for evaluating the benefit-risk trade-offs of diagnostics that assist in medical decision making. Benefit-Risk Evaluation of Diagnostics: A Framework (BED-FRAME) is a strategy for pragmatic evaluation of diagnostics designed to supplement traditional approaches. BED-FRAME evaluates diagnostic yield and addresses 2 key issues: (1) that diagnostic yield depends on prevalence, and (2) that different diagnostic errors carry different clinical consequences. As such, evaluating and comparing diagnostics depends on prevalence and the relative importance of potential errors. BED-FRAME provides a tool for communicating the expected clinical impact of diagnostic application and the expected trade-offs of diagnostic alternatives. BED-FRAME is a useful fundamental supplement to the standard analysis of diagnostic studies that will aid in clinical decision making. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

[Ulcerative contact dermitis caused by premixed concrete (cement burns)].

PubMed

Ancona Alayón; Aranda Martínez, J G

1978-01-01

Cement dermatitis manifests clinically as a chronic dermatitis of irritative character, due to its alkaline nature and as allergic contact dermatitis produced by sensitization to chromium and cobalt occurring as trace elements. the present report deals with a mason without previous dermatitis, presenting bullae, ulcers and necrosis in lower limbs, short time after incidental contact at work, with premixed concrete. The clinical manifestations, such as short evolution, clear limitation to sites in close contact with concrete, negativity to standard patch testing and good prognosis with early treatment, are mentioned. The acute irritant nature of the disease is clear, in opposition to the classical manifestations of cement dermatitis. The need of studies of the chemical properties of this material including pH, alkalinity and the possible roll of additives employed, is part of the strategy for prevention of occupational dermatitis in the building trade, which should include also, information of hazards and proper training in their trade.

Optimal Portfolio Selection Under Concave Price Impact

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

Ma Jin, E-mail: jinma@usc.edu; Song Qingshuo, E-mail: songe.qingshuo@cityu.edu.hk; Xu Jing, E-mail: xujing8023@yahoo.com.cn

2013-06-15

In this paper we study an optimal portfolio selection problem under instantaneous price impact. Based on some empirical analysis in the literature, we model such impact as a concave function of the trading size when the trading size is small. The price impact can be thought of as either a liquidity cost or a transaction cost, but the concavity nature of the cost leads to some fundamental difference from those in the existing literature. We show that the problem can be reduced to an impulse control problem, but without fixed cost, and that the value function is a viscosity solutionmore » to a special type of Quasi-Variational Inequality (QVI). We also prove directly (without using the solution to the QVI) that the optimal strategy exists and more importantly, despite the absence of a fixed cost, it is still in a 'piecewise constant' form, reflecting a more practical perspective.« less

Energy allocation during the maturation of adults in a long-lived insect: implications for dispersal and reproduction.

PubMed

David, G; Giffard, B; van Halder, I; Piou, D; Jactel, H

2015-10-01

Energy allocation strategies have been widely documented in insects and were formalized in the context of the reproduction process by the terms 'capital breeder' and 'income breeder'. We propose here the extension of this framework to dispersal ability, with the concepts of 'capital disperser' and 'income disperser', and explore the trade-off in resource allocation between dispersal and reproduction. We hypothesized that flight capacity was sex-dependent, due to a trade-off in energy allocation between dispersal and egg production in females. We used Monochamus galloprovincialis as model organism, a long-lived beetle which is the European vector of the pine wood nematode. We estimated the flight capacity with a flight mill and used the number of mature eggs as a proxy for the investment in reproduction. We used the ratio between dry weights of the thorax and the abdomen to investigate the trade-off. The probability of flying increased with the adult weight at emergence, but was not dependent on insect age or sex. Flight distance increased with age in individuals but did not differ between sexes. It was also positively associated with energy allocation to thorax reserves, which increased with age. In females, the abdomen weight and the number of eggs also increase with age with no negative effect on flight capacity, indicating a lack of trade-off. This long-lived beetle has a complex strategy of energy allocation, being a 'capital disperser' in terms of flight ability, an 'income disperser' in terms of flight performance and an 'income breeder' in terms of egg production.

Fire-mediated disruptive selection can explain the reseeder-resprouter dichotomy in Mediterranean-type vegetation.

PubMed

Altwegg, Res; De Klerk, Helen M; Midgley, Guy F

2015-02-01

Crown fire is a key selective pressure in Mediterranean-type plant communities. Adaptive responses to fire regimes involve trade-offs between investment for persistence (fire survival and resprouting) and reproduction (fire mortality, fast growth to reproductive maturity, and reseeding) as investments that enhance adult survival lower growth and reproductive rates. Southern hemisphere Mediterranean-type ecosystems are dominated by species with either endogenous regeneration from adult resprouting or fire-triggered seedling recruitment. Specifically, on nutrient-poor soils, these are either resprouting or reseeding life histories, with few intermediate forms, despite the fact that the transition between strategies is evolutionarily labile. How did this strong dichotomy evolve? We address this question by developing a stochastic demographic model to assess determinants of relative fitness of reseeders, resprouters and hypothetical intermediate forms. The model was parameterised using published demographic data from South African protea species and run over various relevant fire regime parameters facets. At intermediate fire return intervals, trade-offs between investment in growth versus fire resilience can cause fitness to peak at either of the extremes of the reseeder-resprouter continuum, especially when assuming realistic non-linear shapes for these trade-offs. Under these circumstances, the fitness landscape exhibits a saddle which could lead to disruptive selection. The fitness gradient between the peaks was shallow, which may explain why this life-history trait is phylogenetically labile. Resprouters had maximum fitness at shorter fire-return intervals than reseeders. The model suggests that a strong dichotomy in fire survival strategy depends on a non-linear trade-off between growth and fire persistence traits.

Mapping Risks of Indonesian Tuna Supply Chain

NASA Astrophysics Data System (ADS)

Karningsih, P. D.; Anggrahini, D.; Kurniati, N.; Suef, M.; Fachrur, A. R.; Syahroni, N.

2018-04-01

Due to its high economic value and is produced by many countries, Tuna is considered as one of the world’s popular fish. Demand for Tuna species are very high and it usually sells in three form: fresh, frozen or canned. Competition in Tuna trading is challengin with the potential risk of price and supply fluctuations. With recent focus of Indonesia government that see the future of Indonesia civilization depend on the oceans and as the three biggest Tuna producing country, Ministry of Marine Affairs and Fisheries should ensure sustainability and competitiveness of Indonesian tuna. Therefore, there is a great need to develop a proper and effective strategy to manage potential risks in Indonesian Tuna supply chain. This paper is aimed at identifying and mapping potential Tuna supply chain risks and its interrelationships that would assist government in determining proper strategies to manage Indonesian Tuna. A framework for identifying Tuna supply chain risks is proposed. Generic risk structure of Supply Chain Risk Identification System is adopted and modified to match with particular object, which is Indonesian Tuna. The proposed model consists of hierarchical and causal structure that encompass potential risks of Tuna supply chain operations from fishing, trading, processing and distribution. The causal structure consist of risk events and its risk agents which is the cause of risk events. To ensure the root cause of risk events are identified properly, five why’s analysis is utilized to obtain risk agents. This proposed model also captures risk interrelationship between internal and external environment of Tuna supply chain. Preliminary result of this study identifies 15 risk events and 13 risk factors on fishing and trading operations and maps their interrelationships.

Sustainability of cross-functional teams for marketing strategy development and implementation.

PubMed

Kono, Ken; Antonucci, Don

2006-01-01

This article presents a case study on a cross-functional team used for marketing strategy development and execution at a health insurance company. The study found a set of success factors that contributed to the initial success of the team, but the factors were not enough to maintain the team's high level of productivity over time. The study later identified a set of 8 factors that helped sustain the team's high-productivity level. The 2 sets (ie, success and its subsequent sustainability factors) are analyzed against a normative model of team effectiveness. All the factors are explained by the normative model except for 1 sustainability factor, "challenge motivator." In fact, the study found the "challenge motivator" to be the most critical factor to keep up the team's productivity over time. Apart from a performance crisis, the authors developed 3 "challenge motivators"--first, more granular market information that could unearth hidden performance issues; second, constant value creation to shareholders as the firm being publicly traded; and third, the firm's strategic mandate to meet and exceed customer expectations that puts ultimate performance pressure on the marketing strategy team.

24 CFR 585.3 - Program components.

Code of Federal Regulations, 2011 CFR

2011-04-01

... construction terminology and concepts; and (3) Strategies to coordinate with local trade unions and apprenticeship programs where possible. (b) Leadership training, counseling and other support activities, including: (1) Activities designed to develop employment and leadership skills, including support for youth...

Reshuffle the deck. A simple plan for improving employee motivation.

PubMed

Casebolt, Keith; Barton, Thompson

2003-04-01

The authors present a strategy for inspiring employees by allowing them to help define their own job roles. As in a bazaar, administrators oversee workers trading tasks and reshaping their positions for maximum effectiveness and job satisfaction.

Assessment of biodiesel scenarios for Midwest freight transport emission reduction.

DOT National Transportation Integrated Search

2010-04-01

There are trade-offs when attempting to reduce both greenhouse gas and criteria air pollutants for freight transport, as the control : strategies are not necessarily complimentary. While emission controls can remove ozone precursors and particulate f...

13 CFR 313.1 - Purpose and scope.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 313.1 Business Credit and Assistance ECONOMIC DEVELOPMENT ADMINISTRATION, DEPARTMENT OF COMMERCE... is designed to assist Communities impacted by trade with economic adjustment through the coordination of Federal, State, and local resources, the creation of community-based development strategies, and...

Field-testing ecological and economic benefits of coffee certification programs.

PubMed

Philpott, Stacy M; Bichier, Peter; Rice, Robert; Greenberg, Russell

2007-08-01

Coffee agroecosystems are critical to the success of conservation efforts in Latin America because of their ecological and economic importance. Coffee certification programs may offer one way to protect biodiversity and maintain farmer livelihoods. Established coffee certification programs fall into three distinct, but not mutually exclusive categories: organic, fair trade, and shade. The results of previous studies demonstrate that shade certification can benefit biodiversity, but it remains unclear whether a farmer's participation in any certification program can provide both ecological and economic benefits. To assess the value of coffee certification for conservation efforts in the region, we examined economic and ecological aspects of coffee production for eight coffee cooperatives in Chiapas, Mexico, that were certified organic, certified organic and fair trade, or uncertified. We compared vegetation and ant and bird diversity in coffee farms and forests, and interviewed farmers to determine coffee yield, gross revenue from coffee production, and area in coffee production. Although there are no shade-certified farms in the study region, we used vegetation data to determine whether cooperatives would qualify for shade certification. We found no differences in vegetation characteristics, ant or bird species richness, or fraction of forest fauna in farms based on certification. Farmers with organic and organic and fair-trade certification had more land under cultivation and in some cases higher revenue than uncertified farmers. Coffee production area did not vary among farm types. No cooperative passed shade-coffee certification standards because the plantations lacked vertical stratification, yet vegetation variables for shade certification significantly correlated with ant and bird diversity. Although farmers in the Chiapas highlands with organic and/or fair-trade certification may reap some economic benefits from their certification status, their farms may not protect as much biodiversity as shade-certified farms. Working toward triple certification (organic, fair trade, and shade) at the farm level may enhance biodiversity protection, increase benefits to farmers, and lead to more successful conservation strategies in coffee-growing regions.

Modelling trading networks and the role of trust

NASA Astrophysics Data System (ADS)

Barrio, Rafael A.; Govezensky, Tzipe; Ruiz-Gutiérrez, Élfego; Kaski, Kimmo K.

2017-04-01

We present a simple dynamical model for describing trading interactions between agents in a social network by considering only two dynamical variables, namely money and goods or services, that are assumed conserved over the whole time span of the agents' trading transactions. A key feature of the model is that agent-to-agent transactions are governed by the price in units of money per goods, which is dynamically changing, and by a trust variable, which is related to the trading history of each agent. All agents are able to sell or buy, and the decision to do either has to do with the level of trust the buyer has in the seller, the price of the goods and the amount of money and goods at the disposal of the buyer. Here we show the results of extensive numerical calculations under various initial conditions in a random network of agents and compare the results with the available related data. In most cases the agreement between the model results and real data turns out to be fairly good, which allow us to draw some general conclusions as how different trading strategies could affect the distribution of wealth in different kinds of societies. Our calculations reveal the striking effects of trust in commercial relations, namely that trust makes trading links more robust and the wealth distribution more even as well as allows for the existence of a healthy middle class.

Life-history trade-offs vary with resource availability across the geographic range of a widespread plant.

PubMed

Villellas, J; García, M B

2018-05-01

Trade-offs between reproduction, growth and survival arise from limited resource availability in plants. Environmental stress is expected to exacerbate these negative correlations, but no studies have evaluated variation in life-history trade-offs throughout species geographic ranges. Here we analyse the costs of growth and reproduction across the latitudinal range of the widespread herb Plantago coronopus in Europe. We monitored the performance of thousands of individuals in 11 populations of P. coronopus, and tested whether the effects of growth and reproduction on a set of vital rates (growth, probability of survival, probability of reproduction and fecundity) varied with local precipitation and soil fertility. To account for variation in internal resources among individuals, we analysed trade-offs correcting for differences in size. Growth was negatively affected by previous growth and reproduction. We also found costs of growth and reproduction on survival, reproduction probability and fecundity, but only in populations with low soil fertility. Costs also increased with precipitation, possibly due to flooding-related stress. In contrast, growth was positively correlated with subsequent survival, and there was a positive covariation in reproduction between consecutive years under certain environments, a potential strategy to exploit temporary benign conditions. Overall, we found both negative and positive correlations among vital rates across P. coronopus geographic range. Trade-offs predominated under stressful conditions, and positive correlations arose particularly between related traits like reproduction investment across years. By analysing multiple and diverse fitness components along stress gradients, we can better understand life-history evolution across species' ranges, and their responses to environmental change. © 2017 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

Vulnerability of animal trade networks to the spread of infectious diseases: a methodological approach applied to evaluation and emergency control strategies in cattle, France, 2005.

PubMed

Rautureau, S; Dufour, B; Durand, B

2011-04-01

Besides farming, trade of livestock is a major component of agricultural economy. However, the networks generated by live animal movements are the major support for the propagation of infectious agents between farms, and their structure strongly affects how fast a disease may spread. Structural characteristics may thus be indicators of network vulnerability to the spread of infectious disease. The method proposed here is based upon the analysis of specific subnetworks: the giant strongly connected components (GSCs). Their existence, size and geographic extent are used to assess network vulnerability. Their disappearance when targeted nodes are removed allows studying how network vulnerability may be controlled under emergency conditions. The method was applied to the cattle trade network in France, 2005. Giant strongly connected components were present and widely spread all over the country in yearly, monthly and weekly networks. Among several tested approaches, the most efficient way to make GSCs disappear was based on the ranking of nodes by decreasing betweenness centrality (the proportion of shortest paths between nodes on which a specific node lies). Giant strongly connected components disappearance was obtained after removal of <1% of network nodes. Under emergency conditions, suspending animal trade activities in a small subset of holdings may thus allow to control the spread of an infectious disease through the animal trade network. Nodes representing markets and dealers were widely affected by these simulated control measures. This confirms their importance as 'hubs' for infectious diseases spread. Besides emergency conditions, specific sensitization and preventive measures should be dedicated to this population. © 2010 Blackwell Verlag GmbH.

Is diversification in male reproductive traits driven by evolutionary trade-offs between weapons and nuptial gifts?

PubMed

Liu, Xingyue; Hayashi, Fumio; Lavine, Laura C; Yang, Ding

2015-05-22

Many male animals have evolved exaggerated traits that they use in combat with rival males to gain access to females and secure their reproductive success. But some male animals invest in nuptial gifts that gains them access to females. Both these reproductive strategies are costly in that resources are needed to produce the weapon or nuptial gift. In closely related species where both weapons and nuptial gifts are present, little is known about the potential evolutionary trade-off faced by males that have these traits. In this study, we use dobsonflies (order Megaloptera, family Corydalidae, subfamily Corydalinae) to examine the presence and absence of enlarged male weapons versus nuptial gifts within and among species. Many dobsonfly species are sexually dimorphic, and males possess extremely enlarged mandibles that they use in battles, whereas in other species, males produce large nuptial gifts that increase female fecundity. In our study, we show that male accessory gland size strongly correlates with nuptial gift size and that when male weapons are large, nuptial gifts are small and vice versa. We mapped weapons and nuptial gifts onto a phylogeny we constructed of 57 species of dobsonflies. Our among-species comparison shows that large nuptial gift production evolved in many species of dobsonfly but is absent from those with exaggerated weapons. This pattern supports the potential explanation that the trade-off in resource allocation between weapons and nuptial gifts is important in driving the diversity of male mating strategies seen in the dobsonflies, whereas reduced male-male competition in the species producing large spermatophores could be an alternative explanation on their loss of male weapons. Our results shed new light on the evolutionary interplay of multiple sexually selected traits in animals. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Minimizing the health and climate impacts of emissions from heavy-duty public transportation bus fleets through operational optimization.

PubMed

Gouge, Brian; Dowlatabadi, Hadi; Ries, Francis J

2013-04-16

In contrast to capital control strategies (i.e., investments in new technology), the potential of operational control strategies (e.g., vehicle scheduling optimization) to reduce the health and climate impacts of the emissions from public transportation bus fleets has not been widely considered. This case study demonstrates that heterogeneity in the emission levels of different bus technologies and the exposure potential of bus routes can be exploited though optimization (e.g., how vehicles are assigned to routes) to minimize these impacts as well as operating costs. The magnitude of the benefits of the optimization depend on the specific transit system and region. Health impacts were found to be particularly sensitive to different vehicle assignments and ranged from worst to best case assignment by more than a factor of 2, suggesting there is significant potential to reduce health impacts. Trade-offs between climate, health, and cost objectives were also found. Transit agencies that do not consider these objectives in an integrated framework and, for example, optimize for costs and/or climate impacts alone, risk inadvertently increasing health impacts by as much as 49%. Cost-benefit analysis was used to evaluate trade-offs between objectives, but large uncertainties make identifying an optimal solution challenging.

When can social media lead financial markets?

PubMed

Zheludev, Ilya; Smith, Robert; Aste, Tomaso

2014-02-27

Social media analytics is showing promise for the prediction of financial markets. However, the true value of such data for trading is unclear due to a lack of consensus on which instruments can be predicted and how. Current approaches are based on the evaluation of message volumes and are typically assessed via retrospective (ex-post facto) evaluation of trading strategy returns. In this paper, we present instead a sentiment analysis methodology to quantify and statistically validate which assets could qualify for trading from social media analytics in an ex-ante configuration. We use sentiment analysis techniques and Information Theory measures to demonstrate that social media message sentiment can contain statistically-significant ex-ante information on the future prices of the S&P500 index and a limited set of stocks, in excess of what is achievable using solely message volumes.

When Can Social Media Lead Financial Markets?

NASA Astrophysics Data System (ADS)

Zheludev, Ilya; Smith, Robert; Aste, Tomaso

2014-02-01

Social media analytics is showing promise for the prediction of financial markets. However, the true value of such data for trading is unclear due to a lack of consensus on which instruments can be predicted and how. Current approaches are based on the evaluation of message volumes and are typically assessed via retrospective (ex-post facto) evaluation of trading strategy returns. In this paper, we present instead a sentiment analysis methodology to quantify and statistically validate which assets could qualify for trading from social media analytics in an ex-ante configuration. We use sentiment analysis techniques and Information Theory measures to demonstrate that social media message sentiment can contain statistically-significant ex-ante information on the future prices of the S&P500 index and a limited set of stocks, in excess of what is achievable using solely message volumes.

When Can Social Media Lead Financial Markets?

PubMed Central

Zheludev, Ilya; Smith, Robert; Aste, Tomaso

2014-01-01

Social media analytics is showing promise for the prediction of financial markets. However, the true value of such data for trading is unclear due to a lack of consensus on which instruments can be predicted and how. Current approaches are based on the evaluation of message volumes and are typically assessed via retrospective (ex-post facto) evaluation of trading strategy returns. In this paper, we present instead a sentiment analysis methodology to quantify and statistically validate which assets could qualify for trading from social media analytics in an ex-ante configuration. We use sentiment analysis techniques and Information Theory measures to demonstrate that social media message sentiment can contain statistically-significant ex-ante information on the future prices of the S&P500 index and a limited set of stocks, in excess of what is achievable using solely message volumes. PMID:24572909

Concurrent System Engineering and Risk Reduction for Dual-Band (RF/optical) Spacecraft Communications

NASA Technical Reports Server (NTRS)

Fielhauer, Karl, B.; Boone, Bradley, G.; Raible, Daniel, E.

2012-01-01

This paper describes a system engineering approach to examining the potential for combining elements of a deep-space RF and optical communications payload, for the purpose of reducing the size, weight and power burden on the spacecraft and the mission. Figures of merit and analytical methodologies are discussed to conduct trade studies, and several potential technology integration strategies are presented. Finally, the NASA Integrated Radio and Optical Communications (iROC) project is described, which directly addresses the combined RF and optical approach.

Integrating pro-environmental behavior with transportation network modeling: User and system level strategies, implementation, and evaluation

NASA Astrophysics Data System (ADS)

Aziz, H. M. Abdul

Personal transport is a leading contributor to fossil fuel consumption and greenhouse (GHG) emissions in the U.S. The U.S. Energy Information Administration (EIA) reports that light-duty vehicles (LDV) are responsible for 61% of all transportation related energy consumption in 2012, which is equivalent to 8.4 million barrels of oil (fossil fuel) per day. The carbon content in fossil fuels is the primary source of GHG emissions that links to the challenge associated with climate change. Evidently, it is high time to develop actionable and innovative strategies to reduce fuel consumption and GHG emissions from the road transportation networks. This dissertation integrates the broader goal of minimizing energy and emissions into the transportation planning process using novel systems modeling approaches. This research aims to find, investigate, and evaluate strategies that minimize carbon-based fuel consumption and emissions for a transportation network. We propose user and system level strategies that can influence travel decisions and can reinforce pro-environmental attitudes of road users. Further, we develop strategies that system operators can implement to optimize traffic operations with emissions minimization goal. To complete the framework we develop an integrated traffic-emissions (EPA-MOVES) simulation framework that can assess the effectiveness of the strategies with computational efficiency and reasonable accuracy. The dissertation begins with exploring the trade-off between emissions and travel time in context of daily travel decisions and its heterogeneous nature. Data are collected from a web-based survey and the trade-off values indicating the average additional travel minutes a person is willing to consider for reducing a lb. of GHG emissions are estimated from random parameter models. Results indicate that different trade-off values for male and female groups. Further, participants from high-income households are found to have higher trade-off values compared with other groups. Next, we propose personal mobility carbon allowance (PMCA) scheme to reduce emissions from personal travel. PMCA is a market-based scheme that allocates carbon credits to users at no cost based on the emissions reduction goal of the system. Users can spend carbon credits for travel and a market place exists where users can buy or sell credits. This dissertation addresses two primary dimensions: the change in travel behavior of the users and the impact at network level in terms of travel time and emissions when PMCA is implemented. To understand this process, a real-time experimental game tool is developed where players are asked to make travel decisions within the carbon budget set by PMCA and they are allowed to trade carbon credits in a market modeled as a double auction game. Random parameter models are estimated to examine the impact of PMCA on short-term travel decisions. Further, to assess the impact at system level, a multi-class dynamic user equilibrium model is formulated that captures the travel behavior under PMCA scheme. The equivalent variational inequality problem is solved using projection method. Results indicate that PMCA scheme is able to reduce GHG emissions from transportation networks. Individuals with high value of travel time (VOTT) are less sensitive to PMCA scheme in context of work trips. High and medium income users are more likely to have non-work trips with lower carbon cost (higher travel time) to save carbon credits for work trips. Next, we focus on the strategies from the perspectives of system operators in transportation networks. Learning based signal control schemes are developed that can reduce emissions from signalized urban networks. The algorithms are implemented and tested in VISSIM micro simulator. Finally, an integrated emissions-traffic simulator framework is outlined that can be used to evaluate the effectiveness of the strategies. The integrated framework uses MOVES2010b as the emissions simulator. To estimate the emissions efficiently we propose a hierarchical clustering technique with dynamic time warping similarity measures (HC-DTW) to find the link driving schedules for MOVES2010b. Test results using the data from a five-intersection corridor show that HC-DTW technique can significantly reduce emissions estimation time without compromising the accuracy. The benefits are found to be most significant when the level of congestion variation is high. In addition to finding novel strategies for reducing emissions from transportation networks, this dissertation has broader impacts on behavior based energy policy design and transportation network modeling research. The trade-off values can be a useful indicator to identify which policies are most effective to reinforce pro-environmental travel choices. For instance, the model can estimate the distribution of trade-off between emissions and travel time, and provide insights on the effectiveness of policies for New York City if we are able to collect data to construct a representative sample. The probability of route choice decisions vary across population groups and trip contexts. The probability as a function of travel and demographic attributes can be used as behavior rules for agents in an agent-based traffic simulation. Finally, the dynamic user equilibrium based network model provides a general framework for energy policies such carbon tax, tradable permit, and emissions credits system.

Optimal teaching strategy in periodic impulsive knowledge dissemination system.

PubMed

Liu, Dan-Qing; Wu, Zhen-Qiang; Wang, Yu-Xin; Guo, Qiang; Liu, Jian-Guo

2017-01-01

Accurately describing the knowledge dissemination process is significant to enhance the performance of personalized education. In this study, considering the effect of periodic teaching activities on the learning process, we propose a periodic impulsive knowledge dissemination system to regenerate the knowledge dissemination process. Meanwhile, we put forward learning effectiveness which is an outcome of a trade-off between the benefits and costs raised by knowledge dissemination as objective function. Further, we investigate the optimal teaching strategy which can maximize learning effectiveness, to obtain the optimal effect of knowledge dissemination affected by the teaching activities. We solve this dynamic optimization problem by optimal control theory and get the optimization system. At last we numerically solve this system in several practical examples to make the conclusions intuitive and specific. The optimal teaching strategy proposed in this paper can be applied widely in the optimization problem of personal education and beneficial for enhancing the effect of knowledge dissemination.

The More the Merrier?. Entropy and Statistics of Asexual Reproduction in Freshwater Planarians

NASA Astrophysics Data System (ADS)

Quinodoz, Sofia; Thomas, Michael A.; Dunkel, Jörn; Schötz, Eva-Maria

2011-04-01

The trade-off between traits in life-history strategies has been widely studied for sexual and parthenogenetic organisms, but relatively little is known about the reproduction strategies of asexual animals. Here, we investigate clonal reproduction in the freshwater planarian Schmidtea mediterranea, an important model organism for regeneration and stem cell research. We find that these flatworms adopt a randomized reproduction strategy that comprises both asymmetric binary fission and fragmentation (generation of multiple offspring during a reproduction cycle). Fragmentation in planarians has primarily been regarded as an abnormal behavior in the past; using a large-scale experimental approach, we now show that about one third of the reproduction events in S. mediterranea are fragmentations, implying that fragmentation is part of their normal reproductive behavior. Our analysis further suggests that certain characteristic aspects of the reproduction statistics can be explained in terms of a maximum relative entropy principle.

Optimal teaching strategy in periodic impulsive knowledge dissemination system

PubMed Central

Liu, Dan-Qing; Wu, Zhen-Qiang; Wang, Yu-Xin; Guo, Qiang

2017-01-01

Accurately describing the knowledge dissemination process is significant to enhance the performance of personalized education. In this study, considering the effect of periodic teaching activities on the learning process, we propose a periodic impulsive knowledge dissemination system to regenerate the knowledge dissemination process. Meanwhile, we put forward learning effectiveness which is an outcome of a trade-off between the benefits and costs raised by knowledge dissemination as objective function. Further, we investigate the optimal teaching strategy which can maximize learning effectiveness, to obtain the optimal effect of knowledge dissemination affected by the teaching activities. We solve this dynamic optimization problem by optimal control theory and get the optimization system. At last we numerically solve this system in several practical examples to make the conclusions intuitive and specific. The optimal teaching strategy proposed in this paper can be applied widely in the optimization problem of personal education and beneficial for enhancing the effect of knowledge dissemination. PMID:28665961

Efficient estimation of the maximum metabolic productivity of batch systems

DOE PAGES

St. John, Peter C.; Crowley, Michael F.; Bomble, Yannick J.

2017-01-31

Production of chemicals from engineered organisms in a batch culture involves an inherent trade-off between productivity, yield, and titer. Existing strategies for strain design typically focus on designing mutations that achieve the highest yield possible while maintaining growth viability. While these methods are computationally tractable, an optimum productivity could be achieved by a dynamic strategy in which the intracellular division of resources is permitted to change with time. New methods for the design and implementation of dynamic microbial processes, both computational and experimental, have therefore been explored to maximize productivity. However, solving for the optimal metabolic behavior under the assumptionmore » that all fluxes in the cell are free to vary is a challenging numerical task. Here, previous studies have therefore typically focused on simpler strategies that are more feasible to implement in practice, such as the time-dependent control of a single flux or control variable.« less

Touring the Saturnian System

NASA Astrophysics Data System (ADS)

Wolf, Aron A.

2002-07-01

The Cassini mission to Saturn employs a Saturn orbiter and a Titan probe to conduct an intensive investigation of the Saturnian system. The orbiter flies a series of orbits, incorporating flybys of the Saturnian satellites, called the ‘satellite tour.’ During the tour, the gravitational fields of the satellites (mainly Titan) are used to modify and control the orbit, targeting from one satellite flyby to the next. The tour trajectory must also be designed to maximize opportunities for a diverse set of science observations, subject to mission-imposed constraints. Tour design studies have been conducted for Cassini over a period of several years to identify trades and strategies for achieving these sometimes conflicting goals. Concepts, strategies, and techniques previously developed for the Galileo mission to Jupiter have been modified, and new ones have been developed, to meet the requirements of the Cassini mission. A sample tour is presented illustrating the application of tour design strategies developed for Cassini.

Concepts and strategies for lunar base radiation protection - Prefabricated versus in-situ materials

NASA Technical Reports Server (NTRS)

Simonsen, Lisa C.; Nealy, John E.; Townsend, Lawrence W.

1992-01-01

The most recently accepted environment data are used as inputs for the Langley nucleon and heavy-ion transport codes, BRYNTRN and HZETRN, to examine the shield effectiveness of lunar regolith in comparison with commercially-used shield materials in nuclear facilities. Several of the fabricated materials categorized as neutron absorbers exhibit favorable characteristics for space radiation protection. In particular, polyethylene with additive boron is analyzed with regard to response to the predicted lunar galactic cosmic ray and solar proton flare environment during the course of a complete solar cycle. Although this effort is not intended to be a definitive trade study for specific shielding recommendations, attention is given to several factors that warrant consideration in such trade studies. For example, the transporting of bulk shield material to the lunar site as opposed to regolith-moving and processing equipment is assessed on the basis of recent scenario studies. The transporting of shield material from Earth may also be a viable alternative to the use of regolith from standpoints of cost-effectiveness, EVA time required, and risk factor.

Cost-benefit trade-offs of bird activity in apple orchards.

PubMed

Peisley, Rebecca K; Saunders, Manu E; Luck, Gary W

2016-01-01

Birds active in apple orchards in south-eastern Australia can contribute positively (e.g., control crop pests) or negatively (e.g., crop damage) to crop yields. Our study is the first to identify net outcomes of these activities, using six apple orchards, varying in management intensity, in south-eastern Australia as a study system. We also conducted a predation experiment using real and artificial codling moth (Cydia pomonella) larvae (a major pest in apple crops). We found that: (1) excluding birds from branches of apple trees resulted in an average of 12.8% more apples damaged by insects; (2) bird damage to apples was low (1.9% of apples); and (3) when trading off the potential benefits (biological control) with costs (bird damage to apples), birds provided an overall net benefit to orchard growers. We found that predation of real codling moth larvae was higher than for plasticine larvae, suggesting that plasticine prey models are not useful for inferring actual predation levels. Our study shows how complex ecological interactions between birds and invertebrates affect crop yield in apples, and provides practical strategies for improving the sustainability of orchard systems.

Evaluating the combined effects of ballast water management and trade dynamics on transfers of marine organisms by ships

PubMed Central

Carney, Katharine J.; Minton, Mark S.; Holzer, Kimberly K.; Miller, A. Whitman; McCann, Linda D.; Ruiz, Gregory M.

2017-01-01

Global trade by merchant ships is a leading mechanism for the unintentional transfer of marine organisms, including non-indigenous species, to bays and estuaries worldwide. To reduce the likelihood of new invasions, ships are increasingly being required to manage their ballast water (BW) prior to discharge in coastal waters. In the United States, most overseas arrivals have been required to manage BW discharge since 2004, primarily through ballast water exchange (BWE), which flushes out ballast tanks in the open ocean (>200 miles from shore). Studies have found BWE to generally reduce the abundance of organisms, and the amount of water exchanged has been estimated at 96–100%. Despite its widespread use, the overall effect of this management strategy on net propagule supply through time has not been explored. Here, temporal changes in zooplankton concentrations and the volume of BW discharged in Chesapeake Bay, U.S. were evaluated, comparing pre-management era and post-management era time periods. Chesapeake Bay is a large port system that receives extensive BW discharge, especially from bulk cargo vessels (bulkers) that export coal overseas. For bulkers arriving from overseas, mean zooplankton concentrations of total and coastal indicator taxa in BW did not decline between pre- (1993–2000) and post management (2012–2013) eras, when controlling for season and sampling method. Moreover, bulkers discharged 21 million tonnes (82% of total for Chesapeake Bay) of overseas BW in 2013, representing a 374% increase in volume when compared to 2005. The combination of BW discharge volume and zooplankton concentration data indicates that (a) net propagule supply by bulkers has increased since BWE began in Chesapeake Bay; and (b) changes in vessel behaviour and trade have contributed strongly to this outcome. Specifically, the coal-driven increase in BW discharge volume from 2005–2013, concurrent with the onset of BWE regulations, worked to counteract intended results from BW management. A long-term analysis of bulker arrivals (1994–2013) reveals a 20-year minimum in arrival numbers in 2000, just when the implementation of BWE began. This study underscores the need to consider shifts in trade patterns, in order to advance and evaluate effective management strategies for biological invasions. PMID:28319119

Evaluating the combined effects of ballast water management and trade dynamics on transfers of marine organisms by ships.

PubMed

Carney, Katharine J; Minton, Mark S; Holzer, Kimberly K; Miller, A Whitman; McCann, Linda D; Ruiz, Gregory M

2017-01-01

Global trade by merchant ships is a leading mechanism for the unintentional transfer of marine organisms, including non-indigenous species, to bays and estuaries worldwide. To reduce the likelihood of new invasions, ships are increasingly being required to manage their ballast water (BW) prior to discharge in coastal waters. In the United States, most overseas arrivals have been required to manage BW discharge since 2004, primarily through ballast water exchange (BWE), which flushes out ballast tanks in the open ocean (>200 miles from shore). Studies have found BWE to generally reduce the abundance of organisms, and the amount of water exchanged has been estimated at 96-100%. Despite its widespread use, the overall effect of this management strategy on net propagule supply through time has not been explored. Here, temporal changes in zooplankton concentrations and the volume of BW discharged in Chesapeake Bay, U.S. were evaluated, comparing pre-management era and post-management era time periods. Chesapeake Bay is a large port system that receives extensive BW discharge, especially from bulk cargo vessels (bulkers) that export coal overseas. For bulkers arriving from overseas, mean zooplankton concentrations of total and coastal indicator taxa in BW did not decline between pre- (1993-2000) and post management (2012-2013) eras, when controlling for season and sampling method. Moreover, bulkers discharged 21 million tonnes (82% of total for Chesapeake Bay) of overseas BW in 2013, representing a 374% increase in volume when compared to 2005. The combination of BW discharge volume and zooplankton concentration data indicates that (a) net propagule supply by bulkers has increased since BWE began in Chesapeake Bay; and (b) changes in vessel behaviour and trade have contributed strongly to this outcome. Specifically, the coal-driven increase in BW discharge volume from 2005-2013, concurrent with the onset of BWE regulations, worked to counteract intended results from BW management. A long-term analysis of bulker arrivals (1994-2013) reveals a 20-year minimum in arrival numbers in 2000, just when the implementation of BWE began. This study underscores the need to consider shifts in trade patterns, in order to advance and evaluate effective management strategies for biological invasions.

The fruit and vegetable import pathway for potential invasive pest arrivals.

PubMed

Lichtenberg, Erik; Olson, Lars J

2018-01-01

The expansion of international trade in commodities increases the risk of alien species invasions. Invaders are difficult to detect on introduction, so prevention remains the preferred strategy for managing the threat of invasions. Propagule pressure has been shown to be a good predictor of invasion risk. Most studies to date, however, link potential invasive species arrivals with indirect measures of propagule pressure such as aggregate trade volumes. This paper estimates propagule pressure using data that measure actual arrivals. Specifically, it uses inspection data that covers almost all U.S. fruit and vegetable imports from 2005-2014 to estimate a logit model of the probability of potential invasive species arrival and expected propagule frequencies for 2,240 commodity/country of origin combinations. Clear patterns in the geographic origin and commodity pathways for potential pests are identified. The average probability of arrival is low, approximately 0.03, but is two to ten times higher for some commodities, most notably herbs. We identify commodities with a high number of expected arrivals due to either a large volume of trade, high interception rates, or a combination of both. Seven of the top ten countries of origin for propagule frequency are from the Western Hemisphere and further trade liberalization within the Western Hemisphere is likely to heighten challenges to enforcement of US phytosanitary standards. Patterns in the data can help identify the commodities and countries of origin in greatest need of technical assistance and guide targeting of surveillance for the pathways of greatest phytosanitary concern.

Touring the Saturnian system

NASA Astrophysics Data System (ADS)

Wolf, Aron A.

1996-10-01

The Cassini mission to Saturn employs a Saturn orbiter and a Titan probe to conduct an intensive investigation of the Saturnian system. The Cassini orbiter flies a series of obits, incorporating flybys of the Saturnian satellites, called the 'satellite tour'. During the tour, the gravitational fields of the satellites are used to modify and control the orbit, targeting from one satellite flyby to the next. The tour trajectory must also be designed to maximize opportunities for science observations, subject to mission-imposed constraints. Tour design studies have been conducted for Cassini to identify trades and strategies for achieving these sometimes conflicting goals. Concepts, strategies, and techniques previously developed for the Galileo mission to Jupiter have been modified, and new ones have been developed, to meet the requirements of the Cassini mission.

Analysis of potential trade-offs in regulation of disinfection by-products

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

Cromwell, J.E.; Zhang, X.; Regli, S.

1992-11-01

Executive Order 12291 requires the preparation of a Regulatory Impact Analysis (RIA) on all new major federal regulations. The goal of an RIA is to develop and organize information on benefits, costs, and economic impacts so as to clarify trade-offs among alternative regulatory options. This paper outlines explicit methodology for assessing the technical potential for risk-risk tradeoffs. The strategies used to cope with complexities and uncertainties in developing the Disinfection By-Products Regulatory Analysis Model are explained. Results are presented and discussed in light of uncertainties, and in light of the analytical requirements for regulatory impact analysis.

Tools, Techniques, and Applications: Normalizing the VR Paradigm

NASA Technical Reports Server (NTRS)

Duncan, Gaeme

2008-01-01

Oshynee's precision Learning Objective performance factor rubrics with associated behavioral anchors integrates with Thinking Worlds(TradeMark), to provide event data recording and dynamic prescriptive feedback. Thinking Worlds(TradeMark) provides SCORM parametric data for reporting within the game and within overarching curricula or workplace evaluation strategy. - Open-sourced, browser-based digital dashboard reporting tools collect data from TW, LMS, LCMS, HR, and workplace metrics or control systems The games may be delivered across the internet or in a range of networked and stand-alone methods using the delivery model (s) required by the host organization.

Universal Industrial Solution and Industrial Sectors Module for Pulp and Paper Sector

EPA Science Inventory

Increased concerns over air pollution and its detrimental effects on health have called for more stringent emission reduction strategies in the industrial sector. However, stringent regulatory policies can potentially adversely affect domestic and international trade. Therefore E...

Strategies for Strengthening Women's Participation in Trade Union Leadership.

ERIC Educational Resources Information Center

Trebilcock, Anne

1991-01-01

Union efforts to increase representation of women in leadership include (1) strong policy commitment; (2) identification of factors/barriers affecting women's leadership; (3) intensified training; and (4) organizational/structural changes such as alteration of rules and adoption of quotas. (SK)

75 FR 71771 - Self-Regulatory Organizations; Notice of Filing of Proposed Rule Change by NASDAQ OMX PHLX, Inc...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-24

... provide investors and traders additional opportunities and strategies to hedge high priced securities... varying yields to the investor. For example if Apple, Inc. (``AAPL'') would trade at $310 \\6\\ with...

7 CFR 1494.20 - Criteria.

Code of Federal Regulations, 2010 CFR

2010-01-01

... strategy of countering competitors' subsidies and other unfair trade practices by displacing such countries....S. agricultural export goals and, in particular, in developing, expanding, or maintaining markets for U.S. agricultural commodities; (c) The effect that sales facilitated by initiatives would have on...

A simulation of air pollution model parameter estimation using data from a ground-based LIDAR remote sensor

NASA Technical Reports Server (NTRS)

Kibler, J. F.; Suttles, J. T.

1977-01-01

One way to obtain estimates of the unknown parameters in a pollution dispersion model is to compare the model predictions with remotely sensed air quality data. A ground-based LIDAR sensor provides relative pollution concentration measurements as a function of space and time. The measured sensor data are compared with the dispersion model output through a numerical estimation procedure to yield parameter estimates which best fit the data. This overall process is tested in a computer simulation to study the effects of various measurement strategies. Such a simulation is useful prior to a field measurement exercise to maximize the information content in the collected data. Parametric studies of simulated data matched to a Gaussian plume dispersion model indicate the trade offs available between estimation accuracy and data acquisition strategy.

Life After the George W. Bush Administration: A New US Strategy Towards China for Future Administrations

DTIC Science & Technology

2008-05-15

the World Trade Organization (WTO) and Asia-Pacific Economic Cooperation ( APEC ).161 In Chapter five, I introduced a balance of ...is doing better, but not equally sharing in the prosperity of the times. Economic inequality in China, according to Dennis Tao Yang, is a product...superpower. This monograph is about strategy—and the use of strategy in guiding actions towards a peer competitor. The

Assessments and market design for the water market at Xiying Irrigation, Shiyang River Basin, Gansu Province, China

NASA Astrophysics Data System (ADS)

Xu, T.; Zhao, J.; Zheng, H.

2016-12-01

As one of the pilot water markets in China, the market in Xiying Irrigation was built in 2008. Based on the historical trading data, it can be concluded that the studied market is growing but facing quite a few challenges. To solve these challenges, the first step we have done is assessment on the market. Some comparable indices were introduced from network science by us. These indices straightforwardly show the status and major problems in the market. One main problem we have found from surveys and our assessment is that there are barriers between distant seller and buyer. This discovery incentives us to develop a new mechanism for matching sellers and buyers to reduce the loss on social welfare. By modelling the trading barriers between a buyer and a seller as an indicator -- tradable or nontradable, the authors propose a mixed-integer linear programming algorithm to optimize the social welfare. According to the theories on competitive equilibrium, the authors are able to extend the programming to compute a reasonable price profile for each pair of tradable seller and buyer. It can be proved that given the price profile, the optimal strategy for each seller or buyer is to follow the optimal assignment. This mechanism significantly reduces the social welfare loss. However, this study shows that removing the trading barriers can brings more social welfare increments.

Differentiation in the water-use strategies among oak species from central Mexico.

PubMed

Aguilar-Romero, Rafael; Pineda-Garcia, Fernando; Paz, Horacio; González-Rodríguez, Antonio; Oyama, Ken

2017-07-01

Oak species (Fagaceae: Quercus) differ in their distribution at the landscape scale, specializing to a certain portion of environmental gradients. This suggests that functional differentiation favors habitat partitioning among closely related species. To elucidate the mechanisms of species coexistence in oak forests, we explored patterns of interspecific variation in functional traits involved in water-use strategies. We tested the hypothesis that oak species segregate along key trade-offs between xylem hydraulic efficiency and safety, and between hydraulic safety and drought avoidance capacity, leading to species niche partitioning across a gradient of aridity. To do so, we quantified biophysical and physiological traits in four red and five white oak species (sections Lobatae and Quercus, respectively) across an aridity gradient in central Mexico. We also explored the trade-offs guiding species differentiation, particularly between the drought tolerance versus water acquisition capacity, and determined whether the water-use strategy was associated with the portion of the environmental gradient that the species occupy. In a trait-by-trait analysis, we detected differences between white and red oak species. However, a larger part of the variation was explained at the species rather than at the section level. We detected two primary axes of trait covariation. The first exhibited differences between species with dense tissues and species with soft tissues (the tissue construction cost axis); however, the oak sections did not constitute separate groups, while the second suggested a trade-off between xylem resistance to cavitation and tree deciduousness. As expected, the water-use strategies of the species were related to the environment; oak species from arid areas had more deciduousness and a higher instantaneous water-use efficiency. In contrast, their humid counterparts had less deciduousness and had a xylem that was more resistant to embolisms. Altogether, these results suggest that aridity filters closely related species, resulting in habitat partitioning and niche divergence. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Cycle 0(CY1991) NLS trade studies and analyses report. Book 1: Structures and core vehicle

NASA Technical Reports Server (NTRS)

1992-01-01

This report (SR-1: Structures, Trades, and Analysis), documents the Core Tankage Trades and analyses performed in support of the National Launch System (NLS) Cycle 0 preliminary design activities. The report covers trades that were conducted on the Vehicle Assembly, Fwd Skirt, LO2 Tank, Intertank, LH2 Tank, and Aft Skirt of the NLS Core Tankage. For each trade study, a two page executive summary and the detail trade study are provided. The trade studies contain study results, recommended changes to the Cycle 0 Baselines, and suggested follow on tasks to be performed during Cycle 1.

Cost-effective management of women with minor cervical lesions: Revisiting the application of HPV DNA testing.

PubMed

Pedersen, Kine; Burger, Emily A; Sy, Stephen; Kristiansen, Ivar S; Kim, Jane J

2016-11-01

Lack of consensus in management guidelines for women with minor cervical lesions, coupled with novel screening approaches, such as human papillomavirus (HPV) genotyping, necessitate revisiting prevention policies. We evaluated the cost-effectiveness and resource trade-offs of alternative triage strategies to inform cervical cancer prevention in Norway. We used a decision-analytic model to compare the lifetime health and economic consequences associated with ten novel candidate approaches to triage women with minor cervical lesions. Candidate strategies varied by: 1) the triage test(s): HPV testing in combination with cytology, HPV testing alone with or without genotyping for HPV-16 and -18, and immediate colposcopy, and 2) the length of time between index and triage testing (i.e., 6, 12 or 18months). Model outcomes included quality-adjusted life-years (QALYs), lifetime societal costs, and resource use (e.g., colposcopy referrals). The current Norwegian guidelines were less effective and more costly than candidate strategies. Given a commonly-cited willingness-to-pay threshold in Norway of $100,000 per QALY gained, the preferred strategy involved HPV genotyping with immediate colposcopy referral for HPV-16 or -18 positive and repeat HPV testing at 12months for non-HPV-16 or -18 positive ($78,010 per QALY gained). Differences in health benefits among candidate strategies were small, while resource use varied substantially. More effective strategies required a moderate increase in colposcopy referrals (e.g., a 9% increase for the preferred strategy) compared with current levels. New applications of HPV testing may improve management of women with minor cervical lesions, yet are accompanied by a trade-off of increased follow-up procedures. Copyright © 2016 Elsevier Inc. All rights reserved.

Cost-effective management of women with minor cervical lesions: Revisiting the application of HPV DNA testing

PubMed Central

Pedersen, Kine; Burger, Emily A.; Sy, Stephen; Kristiansen, Ivar S.; Kim, Jane J.

2016-01-01

Background Lack of consensus in management guidelines for women with minor cervical lesions, coupled with novel screening approaches, such as human papillomavirus (HPV) genotyping, necessitate revisiting prevention policies. We evaluated the cost-effectiveness and resource trade-offs of alternative triage strategies to inform cervical cancer prevention in Norway. Methods We used a decision-analytic model to compare the lifetime health and economic consequences associated with ten novel candidate approaches to triage women with minor cervical lesions. Candidate strategies varied by: 1) the triage test(s): HPV testing in combination with cytology, HPV testing alone with or without genotyping for HPV-16 and-18, and immediate colposcopy, and 2) the length of time between index and triage testing (i.e., 6, 12 or 18 months). Model outcomes included quality-adjusted life-years (QALYs), lifetime societal costs, and resource use (e.g., colposcopy referrals). Results The current Norwegian guidelines were less effective and more costly than candidate strategies. Given a commonly-cited willingness-to-pay threshold in Norway of $100,000 per QALY gained, the preferred strategy involved HPV genotyping with immediate colposcopy referral for HPV-16 or -18 positive and repeat HPV testing at 12 months for non-HPV-16 or -18 positive ($78,010 per QALY gained). Differences in health benefits among candidate strategies were small, while resource use varied substantially. More effective strategies required a moderate increase in colposcopy referrals (e.g., a 9% increase for the preferred strategy) compared with current levels. Conclusion New applications of HPV testing may improve management for women with minor cervical lesions, yet are accompanied by a trade-off of increased follow-up procedures. PMID:27542966

Retailer's optimal credit period and cycle time in a supply chain for deteriorating items with up-stream and down-stream trade credits

NASA Astrophysics Data System (ADS)

Mahata, Gour Chandra

2015-09-01

In practice, the supplier often offers the retailers a trade credit period and the retailer in turn provides a trade credit period to her/his customer to stimulate sales and reduce inventory. From the retailer's perspective, granting trade credit not only increases sales and revenue but also increases opportunity cost (i.e., the capital opportunity loss during credit period) and default risk (i.e., the percentage that the customer will not be able to pay off his/her debt obligations). Hence, how to determine credit period is increasingly recognized as an important strategy to increase retailer's profitability. Also, the selling items such as fruits, fresh fishes, gasoline, photographic films, pharmaceuticals and volatile liquids deteriorate continuously due to evaporation, obsolescence and spoilage. In this paper, we propose an economic order quantity model for the retailer where (1) the supplier provides an up-stream trade credit and the retailer also offers a down-stream trade credit, (2) the retailer's down-stream trade credit to the buyer not only increases sales and revenue but also opportunity cost and default risk, and (3) the selling items are perishable. Under these conditions, we model the retailer's inventory system as a profit maximization problem to determine the retailer's optimal replenishment decisions under the supply chain management. We then show that the retailer's optimal credit period and cycle time not only exist but also are unique. We deduce some previously published results of other researchers as special cases. Finally, we use some numerical examples to illustrate the theoretical results.

Assessing Social – Ecological Trade-Offs to Advance Ecosystem-Based Fisheries Management

PubMed Central

Voss, Rudi; Quaas, Martin F.; Schmidt, Jörn O.; Tahvonen, Olli; Lindegren, Martin; Möllmann, Christian

2014-01-01

Modern resource management faces trade-offs in the provision of various ecosystem goods and services to humanity. For fisheries management to develop into an ecosystem-based approach, the goal is not only to maximize economic profits, but to consider equally important conservation and social equity goals. We introduce such a triple-bottom line approach to the management of multi-species fisheries using the Baltic Sea as a case study. We apply a coupled ecological-economic optimization model to address the actual fisheries management challenge of trading-off the recovery of collapsed cod stocks versus the health of ecologically important forage fish populations. Management strategies based on profit maximization would rebuild the cod stock to high levels but may cause the risk of stock collapse for forage species with low market value, such as Baltic sprat (Fig. 1A). Economically efficient conservation efforts to protect sprat would be borne almost exclusively by the forage fishery as sprat fishing effort and profits would strongly be reduced. Unless compensation is paid, this would challenge equity between fishing sectors (Fig. 1B). Optimizing equity while respecting sprat biomass precautionary levels would reduce potential profits of the overall Baltic fishery, but may offer an acceptable balance between overall profits, species conservation and social equity (Fig. 1C). Our case study shows a practical example of how an ecosystem-based fisheries management will be able to offer society options to solve common conflicts between different resource uses. Adding equity considerations to the traditional trade-off between economy and ecology will greatly enhance credibility and hence compliance to management decisions, a further footstep towards healthy fish stocks and sustainable fisheries in the world ocean. PMID:25268117

Dynamic modeling and optimization for space logistics using time-expanded networks

NASA Astrophysics Data System (ADS)

Ho, Koki; de Weck, Olivier L.; Hoffman, Jeffrey A.; Shishko, Robert

2014-12-01

This research develops a dynamic logistics network formulation for lifecycle optimization of mission sequences as a system-level integrated method to find an optimal combination of technologies to be used at each stage of the campaign. This formulation can find the optimal transportation architecture considering its technology trades over time. The proposed methodologies are inspired by the ground logistics analysis techniques based on linear programming network optimization. Particularly, the time-expanded network and its extension are developed for dynamic space logistics network optimization trading the quality of the solution with the computational load. In this paper, the methodologies are applied to a human Mars exploration architecture design problem. The results reveal multiple dynamic system-level trades over time and give recommendation of the optimal strategy for the human Mars exploration architecture. The considered trades include those between In-Situ Resource Utilization (ISRU) and propulsion technologies as well as the orbit and depot location selections over time. This research serves as a precursor for eventual permanent settlement and colonization of other planets by humans and us becoming a multi-planet species.

Can demand-side policies stop the tobacco industry's damage? Lessons from Turkey.

PubMed

Gultekin-Karakas, Derya

2015-01-01

Trade and investment liberalisation in the post-1980 period allowed the penetration of transnational tobacco companies into the Turkish market. State control over the market was gradually removed and tobacco farming, manufacturing, trade and consumption were reshaped in line with the needs of transnational tobacco companies. The resultant increase in product proliferation and aggressive marketing strategies led to a dramatic rise in cigarette consumption in the 1990s, making Turkey a market with one of the sharpest consumption increases in the world. While Turkey implemented demand-side tobacco control policies to reduce consumption after 1996, it continued to stimulate manufacturing and trade in a conflicting way. The Turkish case verifies that the liberalisation process facilitated by the state under the auspices of international institutions conflicts with tobacco control. Liberalisation paves the way for market expansions of transnational tobacco companies that resist tobacco control in their drive for profit. Current global tobacco control policies, with no interest in controlling manufacturing, have limited effect on consumption. The Turkish case indicates the necessity of establishing public control over tobacco manufacturing and trade from a public health perspective.

Game theory and plant ecology.

PubMed

McNickle, Gordon G; Dybzinski, Ray

2013-04-01

The fixed and plastic traits possessed by a plant, which may be collectively thought of as its strategy, are commonly modelled as density-independent adaptations to its environment. However, plant strategies may also represent density- or frequency-dependent adaptations to the strategies used by neighbours. Game theory provides the tools to characterise such density- and frequency-dependent interactions. Here, we review the contributions of game theory to plant ecology. After briefly reviewing game theory from the perspective of plant ecology, we divide our review into three sections. First, game theoretical models of allocation to shoots and roots often predict investment in those organs beyond what would be optimal in the absence of competition. Second, game theoretical models of enemy defence suggest that an individual's investment in defence is not only a means of reducing its own tissue damage but also a means of deflecting enemies onto competitors. Finally, game theoretical models of trade with mutualistic partners suggest that the optimal trade may reflect competition for access to mutualistic partners among plants. In short, our review provides an accessible entrance to game theory that will help plant ecologists enrich their research with its worldview and existing predictions. © 2013 Blackwell Publishing Ltd/CNRS.

Estimation of dynamic energy budget parameters for the Mediterranean toothcarp (Aphanius fasciatus)

NASA Astrophysics Data System (ADS)

Rinaldi, A.; Montalto, V.; Lika, K.; Sanfilippo, M.; Manganaro, A.; Sarà, G.

2014-11-01

Organisms adopt different sets of physiological, behavioural and morphological trade-offs in order to cope with natural environmental fluctuations. This has consequential rebounds on ecological processes and population dynamics. Such aspects become crucial for sex-dimorphic species, where sex-specific growth variation could mirror different tactics both in energy acquisition and investment between maximum female and male body size with cascading effects on population demography. To date, different approaches have been used in order to understand the causes of individual growth rate changes in ectotherm indeterminate growers, most of which failed. Here, we propose the use of a mechanistic model based on the Dynamic Energy Budget theory (DEB; Koojiman, 2010) to investigate potential differences in energy allocation strategies adopted by individuals of different genders with the Mediterranean toothcarp Aphanius fasciatus (Valenciennes, 1821) as the model species. We collected literature and field data in order to study differences in energy allocation strategies between females and males of the same species by generating projections of possible growth performances: (1) throughout their entire life span and (2) under a context of varying functional responses. Generally, the present exercise of simulations returned different patterns of growth performance among females and males of A. fasciatus, with the former being able to better optimize energetic trade-offs under optimal environmental conditions. The present DEB parameterization exercise represents an essential step towards developing a mechanistic approach to depict metabolic strategies, which are at the base of observed sexual differences, and how such differences may impair ultimate fitness at individual and, therefore, population levels.

A game theory model for stabilizing price of chili: A case study

NASA Astrophysics Data System (ADS)

Wardayanti, Ari; Aviv, Afgan Suffan; Sutopo, Wahyudi; Hisjam, Muh.

2017-11-01

Chili is one of the important agricultural commodity in Indonesia because of its widely consumption by the Indonesian. Chili becomes one of the commodities that experience price fluctuations and important cause of yearly inflation in Indonesia. The unstable price of chili is affected by the scarcity of the commodity in some months and the difference of the harvest season. This study proposes a model to solve the problem by considering the substitution of fresh chilies with dried chili. We propose the cooperative of chili's farmer as entities that process fresh chili into dry ones. The existence of substitution products is expected to maintain the price stability chili. This research was conducted by taking a case study on chili commodity markets in Surakarta which consists of 19 traditional markets. This study aims to create a price stabilization scheme with product substitution using a game theory model. There are 4 strategies proposed in game theory model to describe the relationship between producers and consumers. In this case, the producers are the farmers and the consumers are the trade market. A mixed strategy of was chosen to determine the optimal value among 4 strategies. From the calculation results obtained optimal value when doing a mixed strategy of IDR 201,188,829,000.

Teaching Critical Thinking in the Business Mathematics Course.

ERIC Educational Resources Information Center

Rosenbaum, Roberta

1986-01-01

Appropriate strategies for teaching students to interpret and understand quantitative data in marketing, management, accounting, and data processing are described. Accompanying figures illustrate samples of percentage markups, trade discounts, gross earning, gross commissions, accounting entries, balance sheet entries, and percentage problems. (CT)

Ecosystem Services and Environmental Markets in Chesapeake Bay Restoration

EPA Science Inventory

This report contains two separate analyses, both of which make use of an optimization framework previously developed to evaluate trade-offs in alternative restoration strategies to achieve the Chesapeake Bay Total Maximum Daily Load (TMDL). The first analysis expands on model app...

75 FR 10210 - Market Development Cooperator Program 2010

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-05

...; 4. Help U.S. industry to capitalize on effective global supply chain management strategies; 5... in foreign markets by safeguarding non-U.S. elements of the supply chain with an ingredient testing... Management (OPCM), Manufacturing and Services (MAS), International Trade Administration (ITA), Commerce...

Take a Strategic Direction with Debt.

ERIC Educational Resources Information Center

Augustine, John H.

2002-01-01

Offers advice to higher education institutions about financing decisions on their debt portfolios. Addresses developing a debt management framework, factors affecting strategy, interest rate management, establishing a debt management benchmark, and adopting a prospective approach. Sidebars discuss the trade-offs of credit offerings, and…

The Evolution of Facultative Conformity Based on Similarity.

PubMed

Efferson, Charles; Lalive, Rafael; Cacault, Maria Paula; Kistler, Deborah

2016-01-01

Conformist social learning can have a pronounced impact on the cultural evolution of human societies, and it can shape both the genetic and cultural evolution of human social behavior more broadly. Conformist social learning is beneficial when the social learner and the demonstrators from whom she learns are similar in the sense that the same behavior is optimal for both. Otherwise, the social learner's optimum is likely to be rare among demonstrators, and conformity is costly. The trade-off between these two situations has figured prominently in the longstanding debate about the evolution of conformity, but the importance of the trade-off can depend critically on the flexibility of one's social learning strategy. We developed a gene-culture coevolutionary model that allows cognition to encode and process information about the similarity between naive learners and experienced demonstrators. Facultative social learning strategies that condition on perceived similarity evolve under certain circumstances. When this happens, facultative adjustments are often asymmetric. Asymmetric adjustments mean that the tendency to follow the majority when learners perceive demonstrators as similar is stronger than the tendency to follow the minority when learners perceive demonstrators as different. In an associated incentivized experiment, we found that social learners adjusted how they used social information based on perceived similarity, but adjustments were symmetric. The symmetry of adjustments completely eliminated the commonly assumed trade-off between cases in which learners and demonstrators share an optimum versus cases in which they do not. In a second experiment that maximized the potential for social learners to follow their preferred strategies, a few social learners exhibited an inclination to follow the majority. Most, however, did not respond systematically to social information. Additionally, in the complete absence of information about their similarity to demonstrators, social learners were unwilling to make assumptions about whether they shared an optimum with demonstrators. Instead, social learners simply ignored social information even though this was the only information available. Our results suggest that social cognition equips people to use conformity in a discriminating fashion that moderates the evolutionary trade-offs that would occur if conformist social learning was rigidly applied.

The Evolution of Facultative Conformity Based on Similarity

PubMed Central

Efferson, Charles; Lalive, Rafael; Cacault, Maria Paula; Kistler, Deborah

2016-01-01

Conformist social learning can have a pronounced impact on the cultural evolution of human societies, and it can shape both the genetic and cultural evolution of human social behavior more broadly. Conformist social learning is beneficial when the social learner and the demonstrators from whom she learns are similar in the sense that the same behavior is optimal for both. Otherwise, the social learner’s optimum is likely to be rare among demonstrators, and conformity is costly. The trade-off between these two situations has figured prominently in the longstanding debate about the evolution of conformity, but the importance of the trade-off can depend critically on the flexibility of one’s social learning strategy. We developed a gene-culture coevolutionary model that allows cognition to encode and process information about the similarity between naive learners and experienced demonstrators. Facultative social learning strategies that condition on perceived similarity evolve under certain circumstances. When this happens, facultative adjustments are often asymmetric. Asymmetric adjustments mean that the tendency to follow the majority when learners perceive demonstrators as similar is stronger than the tendency to follow the minority when learners perceive demonstrators as different. In an associated incentivized experiment, we found that social learners adjusted how they used social information based on perceived similarity, but adjustments were symmetric. The symmetry of adjustments completely eliminated the commonly assumed trade-off between cases in which learners and demonstrators share an optimum versus cases in which they do not. In a second experiment that maximized the potential for social learners to follow their preferred strategies, a few social learners exhibited an inclination to follow the majority. Most, however, did not respond systematically to social information. Additionally, in the complete absence of information about their similarity to demonstrators, social learners were unwilling to make assumptions about whether they shared an optimum with demonstrators. Instead, social learners simply ignored social information even though this was the only information available. Our results suggest that social cognition equips people to use conformity in a discriminating fashion that moderates the evolutionary trade-offs that would occur if conformist social learning was rigidly applied. PMID:28002461

Pasture intensification is insufficient to relieve pressure on conservation priority areas in open agricultural markets.

PubMed

Kreidenweis, Ulrich; Humpenöder, Florian; Kehoe, Laura; Kuemmerle, Tobias; Bodirsky, Benjamin Leon; Lotze-Campen, Hermann; Popp, Alexander

2018-04-17

Agricultural expansion is a leading driver of biodiversity loss across the world, but little is known on how future land-use change may encroach on remaining natural vegetation. This uncertainty is, in part, due to unknown levels of future agricultural intensification and international trade. Using an economic land-use model, we assessed potential future losses of natural vegetation with a focus on how these may threaten biodiversity hotspots and intact forest landscapes. We analysed agricultural expansion under proactive and reactive biodiversity protection scenarios, and for different rates of pasture intensification. We found growing food demand to lead to a significant expansion of cropland at the expense of pastures and natural vegetation. In our reference scenario, global cropland area increased by more than 400 Mha between 2015 and 2050, mostly in Africa and Latin America. Grazing intensification was a main determinant of future land-use change. In Africa, higher rates of pasture intensification resulted in smaller losses of natural vegetation, and reduced pressure on biodiversity hotspots and intact forest landscapes. Investments into raising pasture productivity in conjunction with proactive land-use planning appear essential in Africa to reduce further losses of areas with high conservation value. In Latin America, in contrast, higher pasture productivity resulted in increased livestock exports, highlighting that unchecked trade can reduce the land savings of pasture intensification. Reactive protection of sensitive areas significantly reduced the conversion of natural ecosystems in Latin America. We conclude that protection strategies need to adapt to region-specific trade positions. In regions with a high involvement in international trade, area-based conservation measures should be preferred over strategies aimed at increasing pasture productivity, which by themselves might not be sufficient to protect biodiversity effectively. © 2018 John Wiley & Sons Ltd.

Strategies to enable the adoption of animal biotechnology to sustainably improve global food safety and security.

PubMed

Tizard, Mark; Hallerman, Eric; Fahrenkrug, Scott; Newell-McGloughlin, Martina; Gibson, John; de Loos, Frans; Wagner, Stefan; Laible, Götz; Han, Jae Yong; D'Occhio, Michael; Kelly, Lisa; Lowenthal, John; Gobius, Kari; Silva, Primal; Cooper, Caitlin; Doran, Tim

2016-10-01

The ability to generate transgenic animals has existed for over 30 years, and from those early days many predicted that the technology would have beneficial applications in agriculture. Numerous transgenic agricultural animals now exist, however to date only one product from a transgenic animal has been approved for the food chain, due in part to cumbersome regulations. Recently, new techniques such as precision breeding have emerged, which enables the introduction of desired traits without the use of transgenes. The rapidly growing human population, environmental degradation, and concerns related to zoonotic and pandemic diseases have increased pressure on the animal agriculture sector to provide a safe, secure and sustainable food supply. There is a clear need to adopt transgenic technologies as well as new methods such as gene editing and precision breeding to meet these challenges and the rising demand for animal products. To achieve this goal, cooperation, education, and communication between multiple stakeholders-including scientists, industry, farmers, governments, trade organizations, NGOs and the public-is necessary. This report is the culmination of concepts first discussed at an OECD sponsored conference and aims to identify the main barriers to the adoption of animal biotechnology, tactics for navigating those barriers, strategies to improve public perception and trust, as well as industry engagement, and actions for governments and trade organizations including the OECD to harmonize regulations and trade agreements. Specifically, the report focuses on animal biotechnologies that are intended to improve breeding and genetics and currently are not routinely used in commercial animal agriculture. We put forward recommendations on how scientists, regulators, and trade organizations can work together to ensure that the potential benefits of animal biotechnology can be realized to meet the future needs of agriculture to feed the world.

Collaborative decision-analytic framework to maximize resilience of tidal marshes to climate change

USGS Publications Warehouse

Thorne, Karen M.; Mattsson, Brady J.; Takekawa, John Y.; Cummings, Jonathan; Crouse, Debby; Block, Giselle; Bloom, Valary; Gerhart, Matt; Goldbeck, Steve; Huning, Beth; Sloop, Christina; Stewart, Mendel; Taylor, Karen; Valoppi, Laura

2015-01-01

Decision makers that are responsible for stewardship of natural resources face many challenges, which are complicated by uncertainty about impacts from climate change, expanding human development, and intensifying land uses. A systematic process for evaluating the social and ecological risks, trade-offs, and cobenefits associated with future changes is critical to maximize resilience and conserve ecosystem services. This is particularly true in coastal areas where human populations and landscape conversion are increasing, and where intensifying storms and sea-level rise pose unprecedented threats to coastal ecosystems. We applied collaborative decision analysis with a diverse team of stakeholders who preserve, manage, or restore tidal marshes across the San Francisco Bay estuary, California, USA, as a case study. Specifically, we followed a structured decision-making approach, and we using expert judgment developed alternative management strategies to increase the capacity and adaptability to manage tidal marsh resilience while considering uncertainties through 2050. Because sea-level rise projections are relatively confident to 2050, we focused on uncertainties regarding intensity and frequency of storms and funding. Elicitation methods allowed us to make predictions in the absence of fully compatible models and to assess short- and long-term trade-offs. Specifically we addressed two questions. (1) Can collaborative decision analysis lead to consensus among a diverse set of decision makers responsible for environmental stewardship and faced with uncertainties about climate change, funding, and stakeholder values? (2) What is an optimal strategy for the conservation of tidal marshes, and what strategy is robust to the aforementioned uncertainties? We found that when taking this approach, consensus was reached among the stakeholders about the best management strategies to maintain tidal marsh integrity. A Bayesian decision network revealed that a strategy considering sea-level rise and storms explicitly in wetland restoration planning and designs was optimal, and it was robust to uncertainties about management effectiveness and budgets. We found that strategies that avoided explicitly accounting for future climate change had the lowest expected performance based on input from the team. Our decision-analytic framework is sufficiently general to offer an adaptable template, which can be modified for use in other areas that include a diverse and engaged stakeholder group.

Identifying the role of conservation biology for solving the environmental crisis.

PubMed

Dalerum, Fredrik

2014-11-01

Humans are altering their living environment to an extent that could cause environmental collapse. Promoting change into environmental sustainability is therefore urgent. Despite a rapid expansion in conservation biology, appreciation of underlying causes and identification of long-term solutions have largely been lacking. I summarized knowledge regarding the environmental crisis, and argue that the most important contributions toward solutions come from economy, political sciences, and psychology. Roles of conservation biology include providing environmental protection until sustainable solutions have been found, evaluating the effectiveness of implemented solutions, and providing societies with information necessary to align effectively with environmental values. Because of the potential disciplinary discrepancy between finding long-term solutions and short-term protection, we may face critical trade-offs between allocations of resources toward achieving sustainability. Since biological knowledge is required for such trade-offs, an additional role for conservation biologists may be to provide guidance toward finding optimal strategies in such trade-offs.

Optimal execution in high-frequency trading with Bayesian learning

NASA Astrophysics Data System (ADS)

Du, Bian; Zhu, Hongliang; Zhao, Jingdong

2016-11-01

We consider optimal trading strategies in which traders submit bid and ask quotes to maximize the expected quadratic utility of total terminal wealth in a limit order book. The trader's bid and ask quotes will be changed by the Poisson arrival of market orders. Meanwhile, the trader may update his estimate of other traders' target sizes and directions by Bayesian learning. The solution of optimal execution in the limit order book is a two-step procedure. First, we model an inactive trading with no limit order in the market. The dealer simply holds dollars and shares of stocks until terminal time. Second, he calibrates his bid and ask quotes to the limit order book. The optimal solutions are given by dynamic programming and in fact they are globally optimal. We also give numerical simulation to the value function and optimal quotes at the last part of the article.

Research on Chinese Energy Investment in Turkey under the Silk Road Strategy

NASA Astrophysics Data System (ADS)

Huang, Yiling

2017-11-01

In the context of China’s peaceful rise, the Silk Road strategy will promote China participation in Global trade and investment. The Turkish government has announced a new incentive plan to attract investor. Therefore, Chinese energy investment in Turkey is facing some precious opportunities. However, cultural differences, Turkey’s domestic economic problems, political turmoil and other multiple factors bring severe challenges to China’s energy investment in Turkey, which requires a constructive response.