The GPI-Phospholipase C of Trypanosoma brucei Is Nonessential But Influences Parasitemia in Mice

In the mammalian host, the cell surface of Trypanosoma brucei is protected by a variant surface glycoprotein that is anchored in the plasma membrane through covalent attachment of the COOH terminus to a glycosylphosphatidylinositol. The trypanosome also contains a phospholipase C (GPI-PLC) that cleaves this anchor and could thus potentially enable the trypanosome to shed the surface coat of VSG. Indeed, release of the surface VSG can be observed within a few minutes on lysis of trypanosomes in vitro. To investigate whether the ability to cleave the membrane anchor of the VSG is an essential function of the enzyme in vivo, a GPI-PLC null mutant trypanosome has been generated by targeted gene deletion. The mutant trypanosomes are fully viable; they can go through an entire life cycle and maintain a persistent infection in mice. Thus the GPI-PLC is not an essential activity and is not necessary for antigenic variation. However, mice infected with the mutant trypanosomes have a reduced parasitemia and survive longer than those infected with control trypanosomes. This phenotype is partially alleviated when the null mutant is modified to express low levels of GPI-PLC

Extraction and Investigation of Lane Marker Parameters for Steering Signal Prediction

In the work several lane marker parameters, extracted from the visual data that can be used for steering prediction in the intelligent self-learning driver's assistance systems, are presented. Stable parameters that can be used for steering prediction were estimated from the lane marker. The presented parameters show high correlation with a car steering angle. Lane marker detection and lane marker extraction methods from mono-camera images are also considered in the paper