P. falciparum phenotypic plasticity is linked to the variant expression of clonal multigene families such as the var genes. We have examined changes in transcription and histone modifications that occur during sporogonic development of P. falciparum in the mosquito host. All var genes are silenced or transcribed at low levels in blood stages (gametocyte/ring) of the parasite in the human host. ...

The genome of the malaria parasite Plasmodium falciparum contains several multicopy gene families, including var, rifin, stevor and Pfmc-2TM. These gene families undergo expression switching and appear to play a role in antigenic variation. It has recently been shown that forcing parasites to express high copy numbers of transcriptionally active, episomal var promoters led to gradual downregula...

The human malaria parasite Plasmodium falciparum evades host immunity by varying the antigenic and adhesive character of infected erythrocytes. We describe a large and extremely diverse family of P. falciparum genes (var) that encode 200-350 kDa proteins having the expected properties of antigenically variant adhesion molecules. Predicted amino acid sequences of var genes show a variable extrac...

Cytoadherance of Plasmodium falciparum-infected erythrocytes in the brain, organs and peripheral microvasculature is linked to morbidity and mortality associated with severe malaria. Parasite-derived P. falciparum Erythrocyte Membrane Protein 1 (PfEMP1) molecules displayed on the erythrocyte surface are responsible for cytoadherance and undergo antigenic variation in the course of an infection....

We study Wigner ensembles of symmetric random matrices A = (a ij) i; j = 1; : : : ; n with matrix elements a ij ; i j being independent symmetrically distributed random variables a ji = ij n 1 2 : We assume that Var ij = 1 4 , for i < j, Var ii 6const and that all higher moments of ij also exist and grow not faster than the Gaussian ones. Under formulated conditions we prove the central limit t...

This study was undertaken to optimize the conditions for the extraction of antibacterial activity of Perilla frutescens var. acuta leaf against Pseudomonas aeruginosa KCTC 2004 using the evolutionary operation-factorial (EVOP) design technique. Increased antibacterial activity was achieved at higher extraction temperatures and with a longer extraction time. Antibacterial activity was not affect...

Value-at-Risk (VaR) is widely used as a tool for measuring the market risk of asset portfolios. However, alternative VaR implementations are known to yield fairly different VaR forecasts. Hence, every use of VaR requires choosing amongst alternative forecasting models. This paper undertakes two case studies in model selection, for the S&P 500 index and India’s NSE-50 index, at the 95% and 99% l...

Wax D(P), a peptido-glycolipid found in extracts of Mycobacterium tuberculosis var. hominis, was not found in extracts of three strains of still-grown M. tuberculosis var. bovis (BCG, Marmorek and Dupray). However, extracts from three other bovine strains (Behring, LA and BB) did yield waxes D(P), and these did not differ as to their molar ratios of alanine/glutamic acid/diaminopimelic acid fro...

The genetic diversity of 123 wild strains of Pleurotus eryngii var. tuoliensis, which were collected from nine geographical locations in Yumin, Tuoli, and Qinghe counties in the Xinjiang Autonomous Region of China, was analysed using two molecular marker systems (inter-simple sequence repeat and start codon targeted). At the variety level, the percentage of polymorphic loci and Nei's gene diver...

BACKGROUND The reservoir of Plasmodium infection in humans has traditionally been defined by blood slide positivity. This study was designed to characterize the local reservoir of infection in relation to the diverse var genes that encode the major surface antigen of Plasmodium falciparum blood stages and underlie the parasite's ability to establish chronic infection and transmit from human to ...