This article establishes a comprehensive theory of the optimality, robustness, and cross-validation selection consistency for ridge regression under factor-augmented models with possibly dense idiosyncratic information. Using spectral analysis random matrices, we show that is asymptotically efficient in capturing both factor information by minimizing limiting predictive loss among entire class ...

BACKGROUND The variable antigen P. falciparum erythrocyte membrane protein-1 (PfEMP1) is a major virulence factor in malaria. A large number of var genes encode PfEMP1, and we hypothesized that a restricted PfEMP1 repertoire determines clinical disease presentation. We conducted a case-control study in Papua New Guinea and analyzed transcribed var genes in naturally infected children. METHODS...

Monoallelic expression of the var multigene family enables immune evasion of the malaria parasite Plasmodium falciparum in its human host. At a given time only a single member of the 60-member var gene family is expressed at a discrete perinuclear region called the 'var expression site'. However, the mechanism of var gene counting remains ill-defined. We hypothesize that activation factors asso...

In this paper we propose an optimisation approach to determining the optimal decay factor in time weighted (BRW) simulation. Testing of BRW simulation with different decay factors and competing VaR models is performed on a sample of nine Mediterranean countries, over a four year period that includes the ongoing financial crisis. After optimisation the BRW simulation is among the best performing...

This study constructs active Islamic portfolios using a multi-style rotation strategy, derived from the three prominent styles, namely, momentum, value, and quality investing. We use the stocks that are consistently listed in the U.S. Dow Jones Islamic index for a sample period from 1996 to 2012. We also include two macroeconomic mimicking portfolios to capture the premiums of industrial produc...