29 research outputs found
Destabilization of dark states and optical spectroscopy in Zeeman-degenerate atomic systems
We present a general discussion of the techniques of destabilizing dark
states in laser-driven atoms with either a magnetic field or modulated laser
polarization. We show that the photon scattering rate is maximized at a
particular evolution rate of the dark state. We also find that the atomic
resonance curve is significantly broadened when the evolution rate is far from
this optimum value. These results are illustrated with detailed examples of
destabilizing dark states in some commonly-trapped ions and supported by
insights derived from numerical calculations and simple theoretical models.Comment: 14 pages, 10 figure
Cyclin L1 (CCNL1) gene alterations in human head and neck squamous cell carcinoma
We evaluated the expression and amplification of cyclin L1 (CCNL1) gene, a potential oncogene localised in the commonly amplified 3q25–28 region, in human head and neck squamous cell carcinomas (HNSCCs). Overexpression was observed in 55 out of 96 cases (57%) and amplification in nine out of 35 tumours (26%) with no relationships to the clinico-pathological parameters. The Cyclin L1 antibody we developed labels nuclear speckles in tumour cells compatible with a role for CCNL1 in RNA splicing
Reaction of 2-benzoyl-1,2-dihydroisoquinaldonitrile hydrofluoroborate salt with some 1,4 quinones
International audienc
Reaction of 2-benzoyl-1,2-dihydroisoquinaldonitrile hydrofluoroborate salt with some 1,4 quinones
International audienc
J Biol Chem
Genome sequencing revealed an extreme AT-rich genome and a profusion of asparagine repeats associated with Low Complexity Regions (LCR) in proteins of the malarial parasite Plasmodium falciparum. Despite their abundance, the function of these LCRs remains unclear. Because they occur in almost all families of plasmodial proteins, the occurrence of LCRs cannot be associated with any specific metabolic pathway; yet their accumulation must have given selective advantages to the parasite. Translation of these asparagine rich LCRs demands extraordinarily high amounts of asparaginylated tRNAAsn. However, unlike other organisms, Plasmodium codon bias is not correlated to tRNA gene copy number. Here, we studied tRNAAsn accumulation as well as the catalytic capacities of the parasite asparaginyl-tRNA synthetase in vitro. We observed that asparaginylation in this parasite can be considered standard, which is expected to limit the availability of asparaginylated tRNAAsn in the cell and, in turn, slow down the ribosomal translation rate when decoding asparagine repeats. This observation strengthens our earlier hypothesis considering that asparagine rich sequences act as tRNA sponges and help cotranslational folding of parasite proteins. However, it also raises many questions about the mechanistic aspects of the synthesis of asparagine repeats and about their implications in the global control of protein expression throughout Plasmodium life cycle