Effect of bandgap narrowing on performance of modern power devices

The effect of the bandgap narrowing (BGN) on performance of power devices is investigated in detail in this paper. The analysis reveals that the change in the energy band structure caused by BGN can strongly affect the conductivity modulation of the bipolar devices resulting in a completely different performance. This is due to the modified injection efficiency under high-level injection conditions. Using a comprehensive analysis of the injection efficiency in a p-n junction, an analytical model for this phenomenon is developed. BGN model tuning has been proved to be essential in accurately predicting the performance of a lateral insulated-gate bipolar transistor (IGBT). Other devices such as p-i-n diodes or punch-through IGBTs are significantly affected by the BGN, while others, such as field-stop IGBTs or power MOSFETs, are only marginally affected. © 2013 IEEE.

Multiple in-to-Africa dispersals of labeonin fishes (Teleostei: Cyprinidae) revealed by molecular phylogenetic analysis

An out-of-Africa dispersal route has been proposed for many organisms, including modern man. However, counter examples of in-to-Africa dispersal routes are less common. In the present article, the phylogenetic relationships within the Labeoninae, a subfamily of cyprinid fishes distributed in Asia and Africa, were analyzed to investigate the biogeographic processes governing the modern distribution of these Asian and African cyprinids. The mitochondrial DNA cytochrome b gene was used as a molecular marker. The phylogenetic analysis indicated that the subfamily Labeoninae is a monophyletic group, with some Asian labeonins located at the basal position. Two subclades were found that contained both African and Asian species, which highlighted a need for further biogeographic analysis. Based on this analysis, it is proposed that the centre of origin of the Labeoninae was in East Asia. Molecular clock estimation suggests that the Labeoninae arose by the Early Miocene (similar to 23 MYA) during the period of the second Tibetan uplift. Subsequently, two dispersal events of labeonins from Asia into Africa occured in the Early Miocene (similar to 20 MYA) and Late Miocene (similar to 9 MYA) and serve as examples counter to out-of-Africa dispersal.

Cloning, expression and subcellular distribution of a Rana grylio virus late gene encoding ERV1 homologue

An essential for respiration and viability (ERV1) homologue, 88R, was cloned and characterized from Rana grylio virus (RGV). Database searches found its homologues in all sequenced iridoviruses, and sequence alignment revealed a highly conserved motif shared by all ERV1 family proteins: Cys-X-X-Cys. RT-PCR and western blot analysis revealed that 88R begins to transcribe and translate at 6 h postinfection (p.i.) and remains detectable at 48 h p.i. during RGV infection course. Furthermore, using drug inhibition analysis by a de novo protein synthesis inhibitor and a viral DNA replication inhibitor, RGV 88R was classified as a late (L) viral gene during the in vitro infection. 88R-EGFP fusion protein was observed in both the cytoplasm and nucleus of pEGFP-N3-88R transfected EPC cells. Although result of immunofluorescence is similar, 88R protein was not detected in viromatrix. Moreover, function of RGV 88R on virus replication were evaluated by RNAi assay. Nevertheless, effect of knockdown of RGV 88R expression on virus replication was not detected in cultured fish cell lines. Collectively, current data indicate that RGV 88R was a late gene of iridovirus encoding protein that distributed both the cytoplasm and nucleus.

Enduring Borderlands: the Marches of Ireland and Wales in the Early Modern Period

This joint chapter explores similarities and differences between two borderlands within the early modern ‘British’ state – the marches of Ireland and Wales. In some respects, the two regions were very different, most fundamentally because the Irish march remained militarised throughout the Tudor period, while Welsh society was markedly more peaceful. However, there was also much in common. In the later middle ages both marches were frontiers between the expanding Anglo-Normans and native Celtic society. The notion that the march separated ‘civility’ from ‘savagery’ was an enduring one: despite the efforts of the Tudors to impose centralisation and uniformity throughout its territories, there remained institutions, structures of power, and mentalities which ensured that both sets of marches were still in existence by the end of the 16th century. This chapter explores the reasons for the endurance of these borderlands, and indicates how political reforms of the 16th century caused the perception – and sometimes the very location – of the marches to alter.