151 research outputs found
Network analyses in systems biology: new strategies for dealing with biological complexity
The increasing application of network models to interpret biological systems raises a number of important methodological and epistemological questions. What novel insights can network analysis provide in biology? Are network approaches an extension of or in conflict with mechanistic research strategies? When and how can network and mechanistic approaches interact in productive ways? In this paper we address these questions by focusing on how biological networks are represented and analyzed in a diverse class of case studies. Our examples span from the investigation of organizational properties of biological networks using tools from graph theory to the application of dynamical systems theory to understand the behavior of complex biological systems. We show how network approaches support and extend traditional mechanistic strategies but also offer novel strategies for dealing with biological complexity
The Microstructure of a U.S. Treasury ECN: The Brokertec Platform
This paper assesses the microstructure of the U.S. Treasury securities market, using newly available tick data from the BrokerTec electronic trading platform. Examining trading activity, bid-ask spreads, and depth for on-the-run two-, three-, five-, ten-, and thirty-year Treasury securities, we find that market liquidity is greater than that found in earlier studies that use data only from voice-assisted brokers. We find that the price effect of trades on BrokerTec is quite small and is even smaller once order-book information is considered. Moreover, order-book information itself is shown to affect prices. We also explore a novel feature of BrokerTec - the ability to enter hidden ('iceberg') orders - and find that, as predicted by theory, such orders are more common when price volatility is higher
The Role of Data Revisions and Disagreement in Professional Forecasts
This paper aims at evaluating individual expectation accuracy of professional forecasters for 57 U.S., European, and German macroeconomic indicators over the period 1999-2010. The empirical analysis shows that initial announcements are partly considerably revised, and that some revisions occur systematically. Taking into account whether announcements are revised systematically and whether economists (assumingly) aim at forecasting the initial release or the latest revision, signi cant differences can be observed with regard to forecasters' expectation errors. In general, forecasters that are (assumingly) aiming to predict the latest revisions of German indicators are able to form better forecasts if these indicators are revised systematically. Though to a lower extent, this relationship is also observable regarding U.S. indicators. Forecasters' disagreement about fundamentals is higher during recessions and when stock markets are volatile
Trusting Former Rebels: An Experimental Approach to Understanding Reintegration after Civil War
The stability of many post-conflict societies rests on the successful reintegration of former soldiers. We examine social capital of former soldiers in Northern Uganda, where the Lord's Resistance Army forcibly recruited tens of thousands of youth during a recent brutal conflict. We use a set of interlocked experiments to study behavior of ex-soldiers jointly with the behavior of receiving communities towards this group. Consistent with theories that highlight the importance of cooperation during war, we find that individual cooperativeness robustly increases with the length of time a person was with the LRA, especially among those who were abducted during early age. Furthermore, parents of former-soldiers are aware of the behavioral difference: they trust ex-soldiers more because they expect them to be more trustworthy. Last, we find no evidence of preference-based discrimination, suggesting that anger is attenuated when communities do not attribute responsibility for committed violence to returning soldiers. Together, the results reveal that the impact of child soldiering on social capital, in contrast to human capital, is not necessarily detrimental and, speculatively, may facilitate reintegration
Publisher Correction: MEMOTE for standardized genome-scale metabolic model testing
An amendment to this paper has been published and can be accessed via a link at the top of the paper.(undefined)info:eu-repo/semantics/publishedVersio
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