Gene Regulatory Network Reconstruction Using Conditional Mutual Information

<p/> <p>The inference of gene regulatory network from expression data is an important area of research that provides insight to the inner workings of a biological system. The relevance-network-based approaches provide a simple and easily-scalable solution to the understanding of interaction between genes. Up until now, most works based on relevance network focus on the discovery of direct regulation using correlation coefficient or mutual information. However, some of the more complicated interactions such as interactive regulation and coregulation are not easily detected. In this work, we propose a relevance network model for gene regulatory network inference which employs both mutual information and conditional mutual information to determine the interactions between genes. For this purpose, we propose a conditional mutual information estimator based on adaptive partitioning which allows us to condition on both discrete and continuous random variables. We provide experimental results that demonstrate that the proposed regulatory network inference algorithm can provide better performance when the target network contains coregulated and interactively regulated genes.</p

CRKVENOPOVIJESNE TEME U SENJSKOM ZBORNIKU 1 – 29 (1965. − 2002.)

Thermodynamic features of hydrogen production by sorption enhanced steam reforming (SESR) of propane have been studied with the method of Gibbs free energy minimization and contrasted with propane steam reforming (SR). The effects of pressure (1–5 atm), temperature (700–1100 K) and water to propane ratio (WPR, 1–18) on equilibrium compositions and carbon formation are investigated. The results suggest that atmospheric pressure and a WPR of 12 are suitable for hydrogen production from both SR and SESR of propane. High WPR is favourable to inhibit carbon formation. The minimum WPR required to eliminate carbon production is 6 in both SR and SESR. The most favourable temperature for propane SR is approximately 950 K at which 1 mol of propane has the capacity to produce 9.1 mol of hydrogen. The optimum temperature for SESR is approximately 825 K, which is over 100 K lower than that for SR. Other key benefits include enhanced hydrogen production of nearly 10 mol (stoichiometric value) of hydrogen per mole of propane at 700 K, increased hydrogen purity (99% compared with 74% in SR) and no CO2 or CO production with the only impurity being CH4, all indicating a great potential of SESR of propane for hydrogen production

Equilibria for Time-inconsistent Singular Control Problems

We study a time-inconsistent singular control problem originating from irreversible reinsurance decisions with non-exponential discount. Novel definitions of weak and strong equilibria for time-inconsistent singular control problems are introduced. For the problem with non-exponential discount, both sufficient and necessary conditions are derived, providing a thorough mathematical characterization of both equilibria. In particular, the weak equilibrium can be characterized by an extended HJB system, which is a coupled system of non-local parabolic equations with free boundaries. Finally, by showing the existence of classical solutions to the extended HJB system, the existence of weak equilibrium is established under some additional assumptions

On the Nonexistence of Some Generalized Folkman Numbers

For an undirected simple graph $G$, we write $G \rightarrow (H_1, H_2)^v$ if and only if for every red-blue coloring of its vertices there exists a red $H_1$ or a blue $H_2$. The generalized vertex Folkman number $F_v(H_1, H_2; H)$ is defined as the smallest integer $n$ for which there exists an $H$-free graph $G$ of order $n$ such that $G \rightarrow (H_1, H_2)^v$. The generalized edge Folkman numbers $F_e(H_1, H_2; H)$ are defined similarly, when colorings of the edges are considered. We show that $F_e(K_{k+1},K_{k+1};K_{k+2}-e)$ and $F_v(K_k,K_k;K_{k+1}-e)$ are well defined for $k \geq 3$. We prove the nonexistence of $F_e(K_3,K_3;H)$ for some $H$, in particular for $H=B_3$, where $B_k$ is the book graph of $k$ triangular pages, and for $H=K_1+P_4$. We pose three problems on generalized Folkman numbers, including the existence question of edge Folkman numbers $F_e(K_3, K_3; B_4)$, $F_e(K_3, K_3; K_1+C_4)$ and $F_e(K_3, K_3; \overline{P_2 \cup P_3} )$. Our results lead to some general inequalities involving two-color and multicolor Folkman numbers

Assessing the Option Value of Retrofitting a 200MW Power Plant to Oxyfuel CO2 Capture

AbstractAn advantage of oxyfuel capture technology is the flexibility of capable of retrofitting existing conventional coal-fired power plants. This analysis investigates the option value of retrofitting a 200MW coal-fired power plant to Oxyfuel CO2 capture power plant. The initial retrofit option value is the theoretical financial value for pre- investment (Oxyfuel CO2 Capture Ready) to keep the oxyfuel CO2 capture retrofit option open. The study assumes carbon price (either carbon tax or carbon allowance market) is the only driver for oxyfuel CO2 capture retrofit decision and there are no other operational or investment options in the decision making process

Consumption-investment decisions with endogenous reference point and drawdown constraint

We propose a consumption-investment decision model where past consumption peak $h$ plays a crucial role. There are two important consumption levels: the lowest constrained level and a reference level, at which the risk aversion in terms of consumption rate is changed. We solve this stochastic control problem and derive the optimal value function, optimal consumption plan, and optimal investment strategy in semi-explicit forms. We find five important thresholds of wealth, all as functions of $h$, and most of them are implicit nonlinear functions. As can be seen from numerical results, this intuitive and simple model has significant economic implications and there are at least three important predictions: the marginal propensity to consume out of wealth is generally decreasing in wealth but can be increasing with an intermediate level of wealth; the implied relative risk aversion is a smile in wealth; the welfare of the poor is more vulnerable to wealth shocks than the wealthy