Linguistic analysis of letters of recommendation for pediatric otolaryngology: A pilot study.

Objectives: To analyze the language of letters of recommendation for pediatric otolaryngology fellowship for possible gender and/or racial bias. To refine methodology for future investigation of gender and language within letters of recommendation for pediatric otolaryngology fellowship.

Methods: Practicing pediatric otolaryngologists were recruited as survey participants.

The polarization dependence of 2D IR cross-peaks distinguishes parallel-stranded and antiparallel-stranded DNA G-quadruplexes.

Guanine-rich nucleic acid sequences have a tendency to form four-stranded non-canonical motifs known as G-quadruplexes. These motifs may adopt a wide range of structures characterized by size, strand orientation, guanine base conformation, and fold topology. Using three K-bound model systems, we show that vibrational coupling between guanine C6 = O and ring modes varies between parallel-stranded and antiparallel-stranded G-quadruplexes, and that such structures can be distinguished by comparison of the polarization dependences of cross-peaks in their two-dimensional infrared (2D IR) spectra.

Infrared Spectroscopy Reveals the Preferred Motif Size and Local Disorder in Parallel Stranded DNA G-Quadruplexes.

Infrared spectroscopy detects the formation of G-quadruplexes in guanine-rich nucleic acid sequences through shifts in the guanine C=O stretch mode. Here, we use ultrafast 2D infrared (IR) spectroscopy and isotope substitution to show that these shifts arise from vibrational delocalization among stacked G-quartets. This provides a direct measure of the sizes of locally ordered motifs in heterogeneous samples with substantial disordered regions.