13,867 research outputs found
Structure of the twin-arginine signal-binding protein DmsD from Escherichia coli
The translocation of folded proteins via the twin-arginine translocation (Tat) pathway is regulated to prevent the futile export of inactive substrate. DmsD is part of a class of cytoplasmic chaperones that play a role in preventing certain redox proteins from premature transport. DmsD from Escherichia coli has been crystallized in space group P4_12_12, with unit-cell parameters a = b = 97.45, c = 210.04 Ă…, in the presence of a small peptide. The structure has been solved by molecular replacement to a resolution of 2.4 Ă… and refined to an R factor of 19.4%. There are four molecules in the asymmetric unit that may mimic a higher order structure in vivo. There appears to be density for the peptide in a predicted binding pocket, which lends support to its role as the signal-recognition surface for this class of proteins
An integrated control/structure design method using multi-objective optimization
The benefits are demonstrated of a multiobjective optimization based control structure integrated design methodology. An application of the proposed CSI methodology to the integrated design of the Spacecraft COntrol Lab Experiment (SCOLE) configuration is presented. Integrated design resulted in reducing both the control performance measure and the mass. Thus, better overall performance is achieved through integrated design optimization. The mutliobjective optimization approach used provides Pareto optimal solutions by unconstrained minimization of a differentiable KS function. Furthermore, adjusting the parameters gives insight into the trade-offs involved between different objectives
The Transmission of Exchange Rate Changes to Agricultural Prices
Movements in countries’ exchange rates can substantially change the prices of goods faced by producers and consumers and thereby affect incentives to produce, consume, and trade goods. Exchange rate changes, however, might not be completely transmitted (passed through) to domestic prices. Empirical evidence shows that price and exchange rate transmission for agricultural products is low in most developing economies, partly because of trade policies but also because of inadequate infrastructure and other market deficiencies. During the last 20 years, developed and developing countries generally have moved away from support policies that impede price and exchange rate transmission toward trade policies that allow transmission, such as tariffs. The Uruguay Round Agreement on Agriculture of 1994 strongly encouraged this development. Despite these policy changes, market deficiencies remain as a cause of incomplete transmission. Incomplete transmission weakens countries’ integration into world agricultural markets and thereby reduces agricultural trade potential. Low transmission in developing countries also decreases their own benefits from trade, including the gains they could realize if there is further global agricultural liberalization.Agricultural infrastructure, agricultural policy, agricultural trade, exchange rates, exchange rate transmission, imperfect markets, institutions, price transmission., Agribusiness, Agricultural and Food Policy, Agricultural Finance, Financial Economics,
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