A Thermodynamic Model for Active Ion Transport

Active ion transport is very critical for living cells to maintain and regular internal and external environment. It is known that adenosine 5'-triphosphate (ATP) is a general energy source that applies bond energy for pumps to overcome ion concentration gradient. In this study, we introduce a novel thermodynamic model for active ion transport, which allows the pump to act as a 'Maxwell's demon', and also conforms to the second law of thermodynamics. Transport against the gradient is caused by the thermodynamic fluctuation with information recording in ATP stream. Besides, exhaustive experiments about Na-K ATPase performed in the red cell ghost system are reviewed to verify this model, and all the results can support the solvable theory about the working mechanism of demon pumps. Our findings indicate the possible role of ATP as an information carrier but not energy currency. The high-energy phosphate bonds can improve the efficiency of information recording in relevance to ion transport and may mainly convert to heat.Comment: 13 pages, 3 figure

Implementing the Black-Litterman Model with Resampling: A Typical Investment Portfolio with Hedge Funds

Asset allocation decision is ranked as the most important investment decision an investor should make. Researchers have developed many optimization tools to find the best allocation for investors. Our paper will focus on implementing Black-Litterman model together with resampling techniques for portfolio allocations. In our paper, we are going to empirically test the usefulness of those techniques. The results from our research proved that Black-Litterman model and Resampling techniques are advanced methods, which help to generate better allocations than the traditional Markowitz method does. As focusing on typical Canadian investors, our reference portfolio is consisted of S&P TSX, S&P 500, DEX Universe Bond Index, T-Bills and various Canadian hedge funds indices. Using new data sets, we will test whether the results presented in Kooli and Selam’s 2010 paper will still hold. Lastly, further thoughts of our research will be discussed