Graphical modeling of stochastic processes driven by correlated errors

We study a class of graphs that represent local independence structures in stochastic processes allowing for correlated error processes. Several graphs may encode the same local independencies and we characterize such equivalence classes of graphs. In the worst case, the number of conditions in our characterizations grows superpolynomially as a function of the size of the node set in the graph. We show that deciding Markov equivalence is coNP-complete which suggests that our characterizations cannot be improved upon substantially. We prove a global Markov property in the case of a multivariate Ornstein-Uhlenbeck process which is driven by correlated Brownian motions.Comment: 43 page

Schumpeterian micro-economics, international trade and macroeconomic policy

Macroeconomic policy could be much improved if we had a better understanding of the working of the capitalist mechanism. Schumpeter - along with many other economists of the Austrian School - warned the Neoclassical School that the premise on which they were building their models, diminishing returns, was not supported by the evidence. Schumpeter held that with the industrial revolution, increasing rather than decreasing returns were the rule. Schumpeter demonstrated the importance of economies of scale by tracing the trajectories of enterprises in five industries - textiles, railroads, steel, automobiles and electric power - in three countries- The US, Germany and the UK. His main conclusion is that creative destruction is the engine of capitalism.

Innovation: more than research and development. Growth opportunities on different innovation paths

On all levels of economy and society innovations are perceived as key success factor to economic growth and employment. Often it reads as follows: Increased research and development generates technologically innovative products, enabling companies to achieve competitive advantages and gain market shares, which eventually leads to economic growth and employment. This coherence has many times been empirically proven and was again confirmed by the Manufacturing Performance Survey 2003. At the same time the survey also revealed that other promising innovation strategies can be pursued: Companies that achieve innovative breakthroughs by intelligent product-service combinations or innovative techno-organisational processes also are superior to their competitors in regards to employment growth. This indicates that innovation can be more than just research and development. Innovative companies contributing to economic growth and employment can also be found in industrial sectors that are not as dedicated to research. They too ought to be appreciated and supported in their innovation efforts corre spondingly. --

Faithful graphical representations of local independence

Graphical models use graphs to represent conditional independence structure in the distribution of a random vector. In stochastic processes, graphs may represent so-called local independence or conditional Granger causality. Under some regularity conditions, a local independence graph implies a set of independences using a graphical criterion known as $\delta$-separation, or using its generalization, $\mu$-separation. This is a stochastic process analogue of $d$-separation in DAGs. However, there may be more independences than implied by this graph and this is a violation of so-called faithfulness. We characterize faithfulness in local independence graphs and give a method to construct a faithful graph from any local independence model such that the output equals the true graph when Markov and faithfulness assumptions hold. We discuss various assumptions that are weaker than faithfulness, and we explore different structure learning algorithms and their properties under varying assumptions.Comment: 17 pages, 3 figure

Locked nucleic acid oligonucleotides towards clinical applications

Nucleic acid–based therapeutic technologies (Figure 9.1) have significantly advanced in the past two decades toward the treatment of many diseases. The first such drug to enter clinic was vitravene®, an antisense oligonucleotide for the treatment of cytomegalovirus retinitis [1]. Later, research on aptamers led to the marketing of macugen®, an inhibitor of vascular endothelial growth factor (VEGF) for the treatment of age related macular degeneration (AMD) [2]. Nucleic acid–based therapeutic approaches mainly include antisense [3,4], ribozymes [4], small interfering RNA (siRNA) [4–6], microRNA (miRNA) [7–10] targeting and aptamers [11–15]. Oligonucleotides composed of naturally occurring DNA or RNA nucleotides pose some limitations because of their poor RNA binding affinity, low degree of nuclease resistance, and low bioavilability. To overcome these limitations, chemically modified nucleic acids have been introduced, among which locked nucleic acid (LNA) [16–20] proved to be unique and is now used extensively for various applications in chemical biology [21–23]