Optical and structural characterizations were conducted on an InGaAsN quantum well (QW) with large energy bandgap barrier material consisting of InGaAsP (Eg 1⁄4 1:62 eV) grown by metalorganic chemical vapor deposition. A growth pause annealing technique substantially improves both the structural and the optical quality of the QW. With an optimum growth pause of 14 s, surface roughness reduces b...

Transcriptional pausing by RNA polymerase (RNAP) plays an important role in the regulation of gene expression. Defined, sequence-specific pause sites have been identified biochemically. Single-molecule studies have also shown that bacterial RNAP pauses frequently during transcriptional elongation, but the relationship of these "ubiquitous" pauses to the underlying DNA sequence has been uncertai...

Control of pause occurrence and duration is an important issue for text-to-speech synthesis systems. In text-readout speech, pauses occur unconditionally at sentence boundaries and with high probability at major syntactic boundaries such as clause boundaries, but more or less arbitrarily at minor syntactic boundaries. Pause duration tends to be longer at the end of a longer syntactic unit. A de...

In this study we examined whether the arrest of DNA polymerase alpha (pol alpha)-catalyzed DNA synthesis at template pause sites entails terminal nucleotide misincorporation. An approach was developed to identify the 3'-terminal nucleotide in nascent DNA chains that accumulate at pause sites. A radioactive 5'-end-labeled primer was annealed to a bacteriophage M13mp2 single-stranded DNA template...

Gene transcription can be activated by decreasing the duration of RNA polymerase II pausing in the promoter-proximal region, but how this is achieved remains unclear. Here we use a 'multi-omics' approach to demonstrate that the duration of polymerase pausing generally limits the productive frequency of transcription initiation in human cells ('pause-initiation limit'). We further engineer a hum...

ABSTRACT: Relative speech timing was examined in individuals with Parkinson disease (PD) and in agematched control speakers. Relative timing ratios were created from temporal intervals in one phrase containing no pause, one phrase containing an optional pause, and one phrase containing a mandatory pause. Results indicated that there were no relative timing differences between participants with ...

The plasticity of intrinsic excitability has been described in several types of neurons, but the significance of non-synaptic mechanisms in brain plasticity and learning remains elusive. Cerebellar Purkinje cells are inhibitory neurons that spontaneously fire action potentials at high frequencies and regulate activity in their target cells in the cerebellar nuclei by generating a characteristic...