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Exchanges
Kinds of Exchanges Selected AbstractsSTOCK EXCHANGES: East AfricaAFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 5 2009Article first published online: 3 JUL 200 No abstract is available for this article. [source] STOCK EXCHANGES: South AfricaAFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 1 2009Article first published online: 9 MAR 200 No abstract is available for this article. [source] EXCHANGES OF INFORMATION, ENERGY & MATERIALS IN SYMBIOSESJOURNAL OF PHYCOLOGY, Issue 2000J.A. Raven Symbiosis is important in the cell and environmental biology of algae. Some examples involving the author and numerous collaborators include: 1) chloroplasts of eukaryotic algae arose from endosymbioses. Plastids are incapable of independent existence; most of the genes of the cyanobacterial photobiont have been lost, and the majority of the rest have been transferred to the nuclear genome. Some of the genes retained by the plastid are those whose transcription is controlled by environmental cues transduced by the organelle. The general trend is for organelle genes to be transferred to the nucleus, escaping plastid redox activities generating mutagenic free radicals; 2) symbioses involving potentially free-living photobionts include marine lichens and sponges with cyanobacterial symbionts. For the lichen, Lichina, inorganic carbon acquisition appears to involve inorganic carbon transport by the mycobiont, and for the sponge, Cymbastella, the flagellar activity of the sponge is probably important for inorganic carbon supply to the photobiont; 3) the Australasian fucalean, Notheia, is an obligate epiphyte on the fucaleans, Hormosira and Xiphophora; the four species involved all contain the hexitol, altritol. Notheia anomala is known to be phyletically-distant from the other five altritol-containing species. Can Notheia synthesize altritol, or is it obtained from the phorophyte?; 4) Sacoglossan gastropods retain kleptoplastids (not strictly symbionts) from ulvophycean (or rhodophycean) marine algae. Analyses of the natural abundance of stable carbon isotopes suggest significant contribution of kleptoplastid photosynthesis to the carbon and energy budget of the mollusks. [source] WATER EXCHANGES: TOOLS TO BEAT EL NIÑO CLIMATE VARIABILITY IN IRRIGATED AGRICULTURE,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 1 2004Michael J. Scott ABSTRACT: Using a case study of the Yakima River Valley in Washington State, this paper shows that relatively simple tools can be used to forecast the impact of the El Niño phenomenon on water supplies to irrigated agriculture, that this information could be used to estimate the significantly shifted probability distribution of water shortages in irrigated agriculture during El Niño episodes, and that these shifted probabilities can be used to estimate the value of exchanges of water between crops to relieve some of the adverse consequences of such shortages under western water law. Further, recently devised water-trading tools, while not completely free under western water law to respond to forecasted El Niño episodes (ocean circulation patterns), are currently being employed during declared drought to reduce the devastating effects of water shortages in junior water districts on high valued perennial crops. Additional institutional flexibility is needed to take full advantage of climate forecasting, but even current tools clearly could prove useful in controlling the effects of climate variability in irrigated agriculture. Analysis shows the significant benefit of temporarily transferring or renting water rights from low-value to high-value crops, based on El Niño forecasts. [source] HOW FAST DO TOKYO AND NEW YORK STOCK EXCHANGES RESPOND TO EACH OTHER?THE JAPANESE ECONOMIC REVIEW, Issue 2 2010AN ANALYSIS WITH HIGH-FREQUENCY DATA This paper uses one-min returns on the TOPIX and S&P500 to examine the efficiency of the Tokyo and New York Stock Exchanges. Our major finding is that Tokyo completes reactions to New York within six min, but New York reacts within fourteen min. Dividing the sample period into three subperiods, we found that the response time has shortened and the magnitude of reaction has become larger over the period in both markets. The magnitude of response in New York to a fall in Tokyo is roughly double that of a rise. [source] Package Auctions and ExchangesECONOMETRICA, Issue 4 2007Paul Milgrom We report recent advances concerning the package allocation problem, in which traders seek to buy or sell combinations of goods. The problems are most difficult when some goods are not substitutes. In that case, competitive equilibrium typically fail to exist but the core is non-empty and comprises the competitive solutions. Also in that case, the Vickrey auction fails to select core allocations and yield revenues that are less than competitive. The Ausubel-Milgrom auction generally selects core allocations and, when goods are substitutes, prescribes the Vickrey allocation. We also evaluate the problems and promise of mechanisms for the package exchange problem. [source] Competition and Integration among Stock Exchanges in Europe: Network Effects, Implicit Mergers and Remote AccessEUROPEAN FINANCIAL MANAGEMENT, Issue 1 2001Carmine Di Noia The economic theory of network externalities and a simple-game theoretical framework are used to explore the issue of competition among stock exchanges and the possibility of consolidation in the European stock-exchange industry. The paper shows the existence of equilibria where exchanges may decide, even unilaterally, to achieve full compatibility through implicit mergers and remote access, specialising only in trading or listing services. Thus the consolidation of European exchanges into one may occur with a welfare-efficient outcome or with a lock-in to a Pareto-inferior equilibrium, due to the network externalities and the different starting points of the various exchanges. ,Implicit mergers' among exchanges together with remote access are always weakly (in half of the cases, strictly) more efficient than the actual competition. This finding also sheds light on the existence and efficacy, of ATS and rating agencies, which can be viewed respectfully as exchanges specialising in trading and listing services. [source] Development of recombinant inhibitors specific to human kallikrein 2 using phage-display selected substratesFEBS JOURNAL, Issue 3 2004Sylvain M. Cloutier The reactive site loop of serpins undoubtedly defines in part their ability to inhibit a particular enzyme. Exchanges in the reactive loop of serpins might reassign the targets and modify the serpin,protease interaction kinetics. Based on this concept, we have developed a procedure to change the specificity of known serpins. First, reactive loops are very good substrates for the target enzymes. Therefore, we have used the phage-display technology to select from a pentapeptide phage library the best substrates for the human prostate kallikrein hK2 [Cloutier, S.M., Chagas, J.R., Mach, J.P., Gygi, C.M., Leisinger, H.J. & Deperthes, D. (2002) Eur. J. Biochem. 269, 2747,2754]. Selected substrates were then transplanted into the reactive site loop of ,1-antichymotrypsin to generate new variants of this serpin, able to inhibit the serine protease. Thus, we have developed some highly specific ,1-antichymotrypsin variants toward human kallikrein 2 which also show high reactivity. These inhibitors might be useful to help elucidate the importance of hK2 in prostate cancer progression. [source] Geography and the Future of Stock Exchanges: Between Real and Virtual SpaceGROWTH AND CHANGE, Issue 2 2007DARIUSZ WÓJCIK ABSTRACT This paper aims to contribute to the debate on the future of stock exchanges and financial centres by focusing on two questions. First, whether, how, why, and which stock exchange activities are prone to concentration in financial centres? Second, are they prone to concentration in national or international financial centres? Through a detail-rich analysis of stock exchange activities, including trading system, as well as relationships with members, issuers, and investors, the paper suggests a framework for the geography of stock exchange activities based on two dimensions,proneness to concentration in a financial centre and proneness to international consolidation. With this framework, predictions are made about the future geography of stock exchange activities led by the argument that while significant geographical reconfigurations are likely to unfold, driven primarily by the development of international networks of stock market institutions, stock exchanges, and financial centres will remain crucially important for each other. [source] Social, Economic and Demographic Consequences of Migration on KeralaINTERNATIONAL MIGRATION, Issue 2 2001K.C. Zachariah Migration has been the single most dynamic factor in the otherwise dreary development scenario of Kerala during the last quarter of the last century. It has contributed more to poverty alleviation and reduction in unemployment in Kerala than any other factor. As a result of migration, the proportion of the population below the poverty line has declined by 12 per cent. The number of unemployed persons , estimated to be only about 13 lakhs in 1998 compared with 37 lakhs reported by the Kerala Employment Exchanges , has declined by over 30 per cent. Migration has caused nearly a million married women in Kerala to live away from their husbands. Most of these so-called "Gulf wives" experienced extreme loneliness to begin with, and were burdened with added family responsibilities to which they had not been accustomed when their husbands were with them. But over a period, and with a helping hand from abroad over the ISD, most came out of their early gloom. Their gain in autonomy, status, management skills and experience in dealing with the world outside their homes were developed the hard way and would remain with them for the rest of their lives for the benefit of their families and society. In the long run, the transformation of these million women will have contributed more to the development of Kerala society than all the temporary euphoria created by remittances and modern gadgetry. Kerala is dependent on migration for employment, subsistence, housing, household amenities, institution building, and many other developmental activities. The danger is that migration could cease, as shown by the Kuwait war of 1993, and repercussions could be disastrous for the State. Understanding migration trends and instituting policies to maintain the flow of migration is more important today than at any time in the past. Kerala workers seem to be losing out in international competition for jobs in the Gulf market. Corrective policies are needed urgently to raise their competitive edge over workers in competing countries in South and South-East Asia. Like any other industry, migration from Kerala needs periodic technological upgrading of workers. Otherwise, there is a danger that the State might lose the Gulf market permanently. The crux of the problem is Kerala workers' inability to compete with expatriates from other South and South-East Asian countries. The solution lies in equipping workers with better general education and job training. This study suggests a twofold approach. In the short run, the need is to improve the job skills of prospective emigrant workers. This could be achieved through ad hoc training programmes focussed on the job market in Gulf countries. In the long run, the need is to restructure the educational system, taking into consideration the future demand of workers not only in Kerala but also in potential destination countries all over the world, including the US and other developed countries. Kerala emigrants need not always be construction workers in the Gulf countries; they could also be software engineers in developed countries. [source] Measuring Productive Efficiency of Stock Exchanges using Price Adjustment CoefficientsINTERNATIONAL REVIEW OF FINANCE, Issue 1-2 2003Vijaya B. Marisetty A stock exchange's efficiency can be measured by its liquidity and price discovery mechanism. An exchange that provides price discovery will have high liquidity. By measuring the speed of stock price adjustment to its intrinsic value with the arrival of new information, we can understand the price discovery process and productive efficiency of a stock exchange. India has 23 stock exchanges, 20 of which have almost become dysfunctional due to negligible trading during the last five years. Measuring productive efficiency of the current active stock exchanges will help to understand the future direction of the Indian stock market. Using the corrected Damodaran (1993) model and a new model proposed in this paper, I found that information adjustment in the Indian market is very slow. Contrary to the developed markets, in the Indian stock market, stock prices overreact before adjusting to their intrinsic values. I also found that market-wide information adjusts faster than firm-specific information. [source] Privacy and Commercial Use of Personal Data: Policy Developments in the United StatesJOURNAL OF CONTINGENCIES AND CRISIS MANAGEMENT, Issue 1 2003Priscilla Regan In the online and offline worlds, the value of personal information , especially information about commercial purchases and preferences , has long been recognised. Exchanges and uses of personal information have also long sparked concerns about privacy. Public opinion surveys consistently indicate that overwhelming majorities of the American public are concerned that they have lost all control over information about themselves and do not trust organisations to protect the privacy of their information. Somewhat smaller majorities favour federal legislation to protect privacy. Despite public support for stronger privacy protection, the prevailing policy stance for over thirty years has been one of reluctance to legislate and a preference for self-regulation by business to protect privacy. Although some privacy legislation has been adopted, policy debates about the commercial uses of personal information have been dominated largely by business concerns about intrusive government regulation, free speech and the flow of commercial information, costs, and effectiveness. Public concerns about privacy, reflected in public opinion surveys and voiced by a number of public interest groups, are often discredited because individuals seem to behave as though privacy is not important. Although people express concern about privacy, they routinely disclose personal information because of convenience, discounts and other incentives, or a lack of understanding of the consequences. This disconnect between public opinion and public behaviour has been interpreted to support a self-regulatory approach to privacy protections with emphasis on giving individuals notice and choice about information practices. In theory the self-regulatory approach also entails some enforcement mechanism to ensure that organisations are doing what they claim, and a redress mechanism by which individuals can seek compensation if they are wronged. This article analyses the course of policy formulation over the last twenty years with particular attention on how policymakers and stakeholders have used public opinion about the commercial use of personal information in formulating policy to protect privacy. The article considers policy activities in both Congress and the Federal Trade Commission that have resulted in an emphasis on "notice and consent." The article concludes that both individual behaviour and organisational behaviour are skewed in a privacy invasive direction. People are less likely to make choices to protect their privacy unless these choices are relatively easy, obvious, and low cost. If a privacy protection choice entails additional steps, most rational people will not take those steps. This appears logically to be true and to be supported by behaviour in the physical world. Organisations are unlikely to act unilaterally to make their practices less privacy invasive because such actions will impose costs on them that are not imposed on their competitors. Overall then, the privacy level available is less than what the norms of society and the stated preferences of people require. A consent scheme that is most protective of privacy imposes the largest burden on the individual, as well as costs to the individual, while a consent scheme that is least protective of privacy imposes the least burden on the individual, as well as fewer costs to the individual. Recent experience with privacy notices that resulted from the financial privacy provisions in Gramm-Leach-Bliley supports this conclusion. Finally, the article will consider whether the terrorist attacks of 11 September have changed public opinion about privacy and what the policy implications of any changes in public opinion are likely to be. [source] Evolutionary Perspectives on the Development of Social ExchangesNEW DIRECTIONS FOR CHILD & ADOLESCENT DEVELOPMENT, Issue 95 2002Brad E. Sheese Evolutionary theory suggests that developmental context and genetic relatedness may fundamentally alter social exchange processes. [source] An Analysis of Kin-Provided Child Care in the Context of Intrafamily ExchangesAMERICAN JOURNAL OF ECONOMICS AND SOCIOLOGY, Issue 2 2000Linking Components of Family Support for Parents Raising Young Children Little is known about why parents choose kin-provided child care and less is known about how kin-provided child care is related to other forms of in-kind support from relatives close-at-hand. Previous models of the choice of kin-provided child care assumed that the presence of other forms of in-kind support from relatives nearby was inconsequential to estimating effects of economic and demographic factors on the decision to use kin-provided child care. Using data from the National Longitudinal Survey of the Class of 1972, this study shows that this assumption is incorrect because use of kin-provided child care and intrafamily in-kind resource exchanges are interrelated. When the association between use of kin-provided child care and the presence of other family in-kind exchanges is ignored, the study shows that estimated effects for income, the price of child care, and maternal characteristics are underestimated. The findings provide a better understanding of why parents choose kin-provided child care by confirming that this decision is a part of a larger set of parental decisions about involvement in resource exchanges within extended families. My findings support recent child care bills aiming to increase parental choice of child care provider, broaden the definition of a provider to include non-coresident relatives, and expand price subsidies for kin-provided child care. [source] HOW FAST DO TOKYO AND NEW YORK STOCK EXCHANGES RESPOND TO EACH OTHER?THE JAPANESE ECONOMIC REVIEW, Issue 2 2010AN ANALYSIS WITH HIGH-FREQUENCY DATA This paper uses one-min returns on the TOPIX and S&P500 to examine the efficiency of the Tokyo and New York Stock Exchanges. Our major finding is that Tokyo completes reactions to New York within six min, but New York reacts within fourteen min. Dividing the sample period into three subperiods, we found that the response time has shortened and the magnitude of reaction has become larger over the period in both markets. The magnitude of response in New York to a fall in Tokyo is roughly double that of a rise. [source] How Do Exchanges Select Stocks for Option Listing?THE JOURNAL OF FINANCE, Issue 1 2004Stewart Mayhew ABSTRACT We investigate the factors influencing the selection of stocks for option listing. Exchanges tend to list options on stocks with high trading volume, volatility, and market capitalization, but the relative effect of these factors has changed over time as markets have evolved. We observe a shift from volume toward volatility after the moratorium on new listings ended in 1980. Using control sample methodology designed to correct for the endogeneity of option listing, we find no evidence that volatility declines with option introduction, in contrast to previous studies that do not use control samples. [source] Organ Exchanges: Fairness to the O-Blood GroupAMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2006R. M. Veatch No abstract is available for this article. [source] Exchanges of group-based favours: Ingroup bias in the prisoner's dilemma game with minimal groups in Japan and New ZealandASIAN JOURNAL OF SOCIAL PSYCHOLOGY, Issue 3 2008Toshio Yamagishi Japanese (N = 48) and New Zealander (N = 55) participants were first assigned to one of two minimal groups, and then played a prisoner's dilemma game twice with an ingroup member and twice with an outgroup member. In one of the two games they played with an ingroup (or outgroup) member, participants and their partner knew one another's group memberships (mutual-knowledge condition). In the unilateral-knowledge condition, only the participants knew the group membership of their partner, but the partner did not know the group membership of the participant. Ingroup bias in cooperation emerged only in the mutual-knowledge condition in both countries; in the unilateral-knowledge condition no ingroup bias emerged. Mediational analyses found that, in accord with predictions, cooperation in the mutual-knowledge condition is mediated by expectation of the partner's cooperation. Ingroup bias in the mutual-knowledge condition emerged only among those who identified with the ingroup. Results provide support for a group heuristics account of ingroup favouritism in the minimal group. According to this account, participants who face minimal groups activate an ecologically adaptive heuristic of unilaterally cooperating with members of the same group, expecting indirect repayment from others in the same group. [source] The Development of Commodity Exchanges in the Former Soviet Union, Eastern Europe, and ChinaAUSTRALIAN ECONOMIC PAPERS, Issue 4 2001Anne E. Peck The virtual collapse of the centrally planned economies of the countries of the former Soviet Union (FSU) and the more gradual transition from central planning to a market-oriented economy in China were both accompanied by the opening of hundreds of exchanges trading many agricultural, resource, and other physical commodities. Although many viewed them as harbingers of full-fledged market-based economies, most of the new exchanges in fact have since closed either for lack of activity or by government intervention, a history that this paper documents. New exchanges faced numerous obstacles in sustaining interest, from developing standardised contract terms to establishing effective self-regulation and state regulatory oversight. In several countries, the transparency of transactions on exchanges attracted governments interested in collecting taxes and customs duties which only drove trade away from the exchanges or turned them into little more than state agencies. In China, regulators struggled with duplicative exchanges and products, price volatility, large speculative interest, and several manipulations and have recently reduced the number of exchanges to just three and severely limited the commodities traded. There have been some successes too, including (at least prospectively) the three remaining exchanges in China, the Budapest Commodity Exchange in Hungary, and the Poznan Commodity Exchange in Poland. For all, identifying the terms to create standardised contracts has been (and continues to be) a major challenge. [source] Tree-Ring Carbon Isotopic Constraints on Carbon-Water Exchanges between Atmosphere and Biosphere in Drought Regions in Northwestern ChinaACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 2 2000WANG Shilu Abstract The comparison between the carbon isotope and the index of ring width of a pine disc from the Tuomuer Peak region in Xinjiang shows that the effects of climate changes on the tree-ring growth and carbon isotopic fractionation varies with time. The reason is probably relative to the characters of climate changes and adaptability of the tree-ring growth to climate changes. The relationships between the atmospheric CO2 level and the revised ,13Cair by the tree-ring carbon isotope indicate that the carbon cycle is not in a steady state, but under a stage-change condition in this area. It also can be concluded that the ratio of CO2 from the terrestrial eco-system has increased, and the flux of CO2 exchange between the atmosphere and the biosphere was gradually increasing over the past century. In addition, the results also confirm the validity and superiority of the carbon isotope to the research of the water-use efficiency. [source] General Protocols for the Synthesis of C2 -Symmetric and Asymmetric 2,8-Disubstituted Analogues of Troeger,s Base via Efficient Bromine,Lithium Exchanges of 2,8-Dibromo-6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine.CHEMINFORM, Issue 5 2003Jacob Jensen Abstract For Abstract see ChemInform Abstract in Full Text. [source] Simulating the Dynamics of Spouted-Bed Nuclear Fuel Coaters,CHEMICAL VAPOR DEPOSITION, Issue 9 2007S. Pannala Abstract We describe simulation studies of the dynamics of spouted beds used for CVD coating of nuclear fuel particles. Our principal modeling tool is the Multiphase Flow with Interphase eXchanges (MFIX) code that was originally developed by the National Energy Technology Laboratory (NETL) for fossil energy process applications. In addition to standard MFIX features that allow coupling of transient hydrodynamics, heat and mass transfer, and chemical kinetics, we employ special post-processing tools to track particle mixing and circulation as functions of operating conditions and bed design. We describe in detail one major feature of the dynamics, which is the occurrence of very regular spontaneous pulsations of gas and particle flow in the spout. These pulsations appear to be critically linked to the entrainment and circulation of solids, and they produce readily accessible dynamic pressure variations that can be used for direct comparisons of model predictions with experiments. Spouted-bed dynamics are important from a CVD perspective because they directly determine the magnitude and variability of the concentration and species gradients in the zone where reactant gases first come into contact with hot particles. As this unsteady spouted-bed environment differs from other types of CVD reactors, the design and scale-up of such reactors is likely to involve unique modeling issues. Our primary goal here is to lay the groundwork for how computational simulation can be used to address these modeling issues in the specific context of nuclear fuel particle coating. [source] Why bartering biodiversity failsCONSERVATION LETTERS, Issue 4 2009Susan Walker Abstract Regulatory biodiversity trading (or biodiversity "offsets") is increasingly promoted as a way to enable both conservation and development while achieving "no net loss" or even "net gain" in biodiversity, but to date has facilitated development while perpetuating biodiversity loss. Ecologists seeking improved biodiversity outcomes are developing better assessment tools and recommending more rigorous restrictions and enforcement. We explain why such recommendations overlook and cannot correct key causes of failure to protect biodiversity. Viable trading requires simple, measurable, and interchangeable commodities, but the currencies, restrictions, and oversight needed to protect complex, difficult-to-measure, and noninterchangeable resources like biodiversity are costly and intractable. These safeguards compromise trading viability and benefit neither traders nor regulatory officials. Political theory predicts that (1) biodiversity protection interests will fail to counter motivations for officials to resist and relax safeguards to facilitate exchanges and resource development at cost to biodiversity, and (2) trading is more vulnerable than pure administrative mechanisms to institutional dynamics that undermine environmental protection. Delivery of no net loss or net gain through biodiversity trading is thus administratively improbable and technically unrealistic. Their proliferation without credible solutions suggests biodiversity offset programs are successful "symbolic policies," potentially obscuring biodiversity loss and dissipating impetus for action. [source] BUSINESS METHOD PATENTS AND U.S. FINANCIAL SERVICESCONTEMPORARY ECONOMIC POLICY, Issue 3 2010ROBERT M. HUNT A decade after the State Street decision, more than 1,000 business method patents are granted each year. Yet, only 1 in 10 is obtained by a financial institution. Most business method patents are also software patents. Have these patents increased innovation in financial services? To address this question, we construct new indicators of research and development intensity based on the occupational composition of financial industries. The financial sector appears more research intensive than official statistics would suggest but less than the private economy taken as a whole. There is considerable variation across industries but little apparent trend. There does not appear to be an obvious effect from business method patents on the sector's research intensity. Looking ahead, three factors suggest that the patent system may affect financial services as it has electronics: (1) the sector's heavy reliance on information technology, (2) the importance of standard setting, and (3) the strong network effects exhibited in many areas of finance. Even today litigation is not uncommon; we sketch a number of significant examples affecting financial exchanges and consumer payments. The legal environment is changing quickly. We review a number of important federal court decisions that will affect how business method patents are obtained and enforced. We also review a number of proposals under consideration in the U.S. Congress. (JEL O31, O34, G20) [source] A physiologically based pharmacokinetic model of vascular,extravascular exchanges during liver carcinogenesis: application to MRI contrast agentsCONTRAST MEDIA & MOLECULAR IMAGING, Issue 5 2007Muriel Mescam Abstract The extraction of physiological parameters by non-invasive imaging techniques such as dynamic magnetic resonance imaging (MRI) or positron emission tomography requires a knowledge of molecular distribution and exchange between microvascularization and extravascular tissues. These phenomena not only depend on the physicochemical characteristics of the injected molecules but also the pathophysiological state of the targeted organ. We developed a five-compartment physiologically based pharmacokinetic model focused on hepatic carcinogenesis and MRI contrast agents. This model includes physical characteristics of the contrast agent, dual specific liver supply, microvessel wall properties and transport parameters that are compatible with hepatocarcinoma development. The evolution of concentrations in the five compartments showed significant differences in the distribution of three molecules (differentiated by their diameters and diffusion coefficients ranging, respectively, from 0.9 to 62,nm and from 68.10,9 to 47.10,7,cm2,s,1) in simulated regeneration nodules and dysplastic nodules, as well as in medium- and poorly differentiated hepatocarcinoma. These results are in agreement with known vascular modifications such as arterialization that occur during hepatocarcinogenesis. This model can be used to study the pharmacokinetics of contrast agents and consequently to extract parameters that are characteristic of the tumor development (like permeability), after fitting simulated to in vivo data. Copyright © 2007 John Wiley & Sons, Ltd. [source] The Productive Life of RiskCULTURAL ANTHROPOLOGY, Issue 3 2004Caitlin Zaloom Contemporary social theorists usually conceive of risk negatively. Focusing on disasters and hazards, they see risk as an object of calculation and avoidance. But we gain a deeper understanding of risk in modern life if we observe it in another setting. Futures markets are exemplary sites of aggressive risk taking. Drawing upon extensive fieldwork on trading floors, this article shows how a high modern institution creates populations of risk-taking specialists, and explores the ways that engagements with risk actively organize contemporary markets and forge economic actors. Financial exchanges are crucibles of capitalist production. At the Chicago Board of Trade, financial speculators structure their conduct and shape themselves around risk; and games organized around risk influence the social and spatial dynamics of market life. [source] Actin-like protein 1 (ALP1) is a component of dynamic, high molecular weight complexes in Toxoplasma gondii,CYTOSKELETON, Issue 1 2010Jennifer L. Gordon Abstract Apicomplexan parasites, such as Toxoplasma gondii, rely on actin-based motility for cell invasion, yet conventional actin does not appear to be required for cell division in these parasites. Apicomplexans also contain a variety of actin-related proteins (Arps); however, most of these not directly orthologous to Arps in well-studied systems. We recently identified an apicomplexan-specific member of this family called Actin-Like Protein 1, (ALP1), which plays a role in the assembly of vesicular components recruited to the inner membrane complex (IMC) of daughter cells during cell division. In addition to its enrichment at daughter cell membranes, ALP1 is localized throughout the cytoplasm both diffusely distributed and concentrated in clusters that are detected by fluorescence microscopy, suggesting it forms complexes. Using quantitative optical imaging methods, including fluorescence recovery after photobleaching (FRAP) and fluorescence loss in photobleaching (FLIP), we demonstrated that ALP1 is a component of a large complex, and that it readily exchanges between diffusible and complex-bound forms. Sedimentation and density gradient analyses revealed that ALP1 is found in a freely soluble state as well as high molecular weight complexes. During cell division, ALP1 was dynamically associated with the IMC, suggesting it rapidly cycles between freely diffusible and complex forms during daughter cell assembly. © 2009 Wiley-Liss, Inc. [source] Reverse Auctions with Multiple Reinforcement Learning Agents,DECISION SCIENCES, Issue 1 2008Subhajyoti Bandyopadhyay ABSTRACT Reverse auctions in business-to-business (B2B) exchanges provide numerous benefits to participants. Arguably the most notable benefit is that of lowered prices driven by increased competition in such auctions. The competition between sellers in reverse auctions has been analyzed using a game-theoretic framework and equilibria have been established for several scenarios. One finding of note is that, in a setting in which sellers can meet total demand with the highest-bidding seller being able to sell only a fraction of the total capacity, the sellers resort to a mixed-strategy equilibrium. Although price randomization in industrial bidding is an accepted norm, one might argue that in reality managers do not utilize advanced game theory calculations in placing bids. More likely, managers adopt simple learning strategies. In this situation, it remains an open question as to whether the bid prices converge to the theoretical equilibrium over time. To address this question, we model reverse-auction bidding behavior by artificial agents as both two-player and n -player games in a simulation environment. The agents begin the game with a minimal understanding of the environment but over time analyze wins and losses for use in determining future bids. To test for convergence, the agents explore the price space and exploit prices where profits are higher, given varying cost and capacity scenarios. In the two-player case, the agents do indeed converge toward the theoretical equilibrium. The n -player case provides results that reinforce our understanding of the theoretical equilibria. These results are promising enough to further consider the use of artificial learning mechanisms in reverse auctions and other electronic market transactions, especially as more sophisticated mechanisms are developed to tackle real-life complexities. We also develop the analytical results when one agent does not behave strategically while the other agent does and show that our simulations for this environment also result in convergence toward the theoretical equilibrium. Because the nature of the best response in the new setting is very different (pure strategy as opposed to mixed), it indicates the robustness of the devised algorithm. The use of artificial agents can also overcome the limitations in rationality demonstrated by human managers. The results thus have interesting implications for designing artificial agents in automating bid responses for large numbers of bids where human intervention might not always be possible. [source] CHALLENGES FACED BY RESEARCH ETHICS COMMITTEES IN EL SALVADOR: RESULTS FROM A FOCUS GROUP STUDYDEVELOPING WORLD BIOETHICS, Issue 1 2009JONATHAN W. CAMP ABSTRACT Objective:, To identify perceived barriers to capacity building for local research ethics oversight in El Salvador, and to set an agenda for international collaborative capacity building. Methods:, Focus groups were formed in El Salvador which included 17 local clinical investigators and members of newly formed research ethics committees. Information about the proposed research was presented to participants during an international bioethics colloquium sponsored and organized by the St. Jude Children's Research Hospital in collaboration with the National Ethics Committee of El Salvador and the University of El Salvador. Interviews with the focus group participants were qualitatively analyzed. Results:, Participants expressed the need to tailor the informed consent process and documentation to the local culture; for example, allowing family members to participate in decision-making, and employing shorter consent forms. Participants indicated that economic barriers often impede efforts in local capacity building. Participants valued international collaboration for mutual capacity building in research ethics oversight. Conclusions:, Research ethics committees in El Salvador possess a basic knowledge of locally relevant ethical principles, though they need more training to optimize the application of bioethical principles and models to their particular contexts. Challenges increase the value of collaborative exchanges with ethics committee members in the United States. Further research on facilitating communication between host country and sponsor country ethics committees can maximize local research ethics expertise, and thus raise the standard of protecting human participants involved in international research. [source] Survey of dietetic provision for patients with diabetesDIABETIC MEDICINE, Issue 8 2000M. Nelson SUMMARY Aims To survey dietitians involved in diabetes care regarding the provisions for patients with diabetes. Methods A national survey of 512 dietitians known to be engaged in provision of diabetes care was conducted in 1997 and 391 (76%) responded. Results Nationally the median provision of dietetic care for diabetes reported was 10.7 h per 100 000 general population per week, but the provision was uneven ranging from 2.0 to 27.6 h per 100 000. Eighty-five per cent of dietitians worked in areas where the provision was less than 22 h per 100 000 general population per week (the current recommended minimum standard). Dietetic provision was greater in secondary care (median 9.1 h per 100 000 general population per week) than in general practice, residential homes and other locations (median 4.4 h per 100 000 general population per week). Provision was greater in those areas in which a designated dietitian had responsibility for co-ordinating the dietetic service for diabetes than in areas where the co-ordinator was not a dietitian or where there was no co-ordinator. Over 90% of dietitians reported following British Diabetic Association (BDA) recommendations regarding advice on carbohydrate, sugar, fat and fibre consumption, but only one-third routinely advised on salt restriction. Of the 17% of dietitians who continue to use carbohydrate exchanges, all combine this method with other approaches. Of the recommendations made by the Clinical Standards Group, only 69% of dietitians reported seeing more than half of newly diagnosd adult patients within four weeks, and less than 50% reported offering half or more of their patients an annual review. Amongst the literature in current use, 98% of dietitians use BDA literature for teaching patients and 90% use BDA publications in their own education. Seventy-six per cent of dietitians believed that there was a role for commercial slimming organizations in weight management of people with diabetes Conclusions Given the proven value of dietetic input in diabetes management, there would be advantages to correcting the regional inequalities in dietetic provision for diabetes care in the UK. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||