This tutorial review considers defect chemistry of TiO2 and its solid solutions as well as defect-related properties associated with solar-to-chemical energy conversion, such as Fermi level, bandgap, charge transport and surface active sites. Defect disorder is discussed in terms of defect reactions and the related charge compensation. Defect equilibria are used in derivation of defect diagrams showing the effect of oxygen activity and temperature on the concentration of both ionic and electronic defects. These defect diagrams may be used for imposition of desired semiconducting properties that are needed to maximize the performance of TiO2-based photoelectrodes for the generation of solar hydrogen fuel using photo electrochemical cells (PECs) and photocatalysts for water purification. The performance of the TiO2-based semiconductors is considered in terms of the key performance-related properties (KPPs) that are defect related. It is shown that defect engineering may be applied for optimization of the KPPs in order to achieve optimum performance.

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Partial (DNA) sequences were collected for 2 mitochondrial loci (Srrna and Lrrna, the rrnS and rrnL rRNA genes respectively) for Schistosoma indicum group species from 4 Southeast Asian countries. The samples included 7 populations, 4 of which were previously unstudied. In 11 cases the combination of locus and population was new. The aim of the study was to provide a phylogeny based on new independent data and multiple populations (earlier studies had mostly used a common set of field samples or laboratory lines) and to examine interrelationships and phylogeography within this species group. Paraphyly of the S. indicum group was confirmed, as was the basal position of Schistosoma incognitum in the Schistosoma phylogeny. Southeast Asian Schistosoma spindale and S. incognitum populations were shown to fall into their respective con-specific cohesive groupings. Estimated divergence times for these taxa were shown to be related to Pleistocene changes in sea level and the radiation of definitive host groups. A revised phylogeographical model is proposed in the light of these findings.

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