The two-component system CroRS acts as a master regulator of cell envelope homeostasis to confer antimicrobial tolerance in the bacterial pathogen Enterococcus faecalis.

Antimicrobial tolerance is the ability of a microbial population to survive, but not proliferate, during antimicrobial exposure. Significantly, it has been shown to precede the development of bona fide antimicrobial resistance. We have previously identified the two-component system CroRS as a critical regulator of tolerance to antimicrobials like teixobactin in the bacterial pathogen Enterococcus faecalis.

Antimicrobial tolerance and its role in the development of resistance: Lessons from enterococci.

Bacteria have developed resistance against every antimicrobial in clinical use at an alarming rate. There is a critical need for more effective use of antimicrobials to both extend their shelf life and prevent resistance from arising. Significantly, antimicrobial tolerance, i.

Ultra-high resolution and broadband chip-scale speckle enhanced Fourier-transform spectrometer.

Recent advancements in silicon photonics are enabling the development of chip-scale photonics devices for sensing and signal processing applications, among which on-chip spectrometers are of particular interest for precision wavelength monitoring and related applications. Most chip-scale spectrometers suffer from a resolution-bandwidth trade-off, thus limiting the uses of the device. Here we report on a novel passive, chip-scale, hybrid speckle-enhanced Fourier transform device that exhibits a two order-of-magnitude improvement in finesse (bandwidth/resolution) over the state-of-the art chip-scale speckle and Fourier transform spectrometers.

Genomewide Profiling of the Enterococcus faecalis Transcriptional Response to Teixobactin Reveals CroRS as an Essential Regulator of Antimicrobial Tolerance.

Teixobactin is a new antimicrobial of significant interest. It is active against a number of multidrug-resistant pathogens, including and , with no reported mechanisms of teixobactin resistance. However, historically, mechanisms of resistance always exist and arise upon introduction of a new antimicrobial into a clinical setting.

SBS reduction in nanosecond fiber amplifiers by frequency chirping.

We demonstrate a technique for SBS reduction in a nanosecond Yb-fiber amplifier by imposing 1.19 GHz/ns frequency chirp on the seed pulses with a pulse-driven phase modulator. A nearly 9-fold increase in the SBS threshold was observed for 8.

Narrowband Er:YAG nonplanar ring oscillator at 1645 nm.

We report 1645 nm narrowband operation of a monolithic Er:YAG nonplanar ring oscillator resonantly pumped at 1532 nm. Unidirectional cw power up to 0.5 W was obtained with a measured linewidth of 21 kHz.

Multiwatt continuous-wave and Q-switched Er:YAG lasers at 1645 nm: performance issues.

The cw and Q-switched performance of Er:YAG lasers operating at 1645 nm were measured. Guided by previous work in the literature, we sought to improve efficiency at low pulse repetition frequencies by decreasing the doping level from 0.5 to 0.

Time-gated filter for sideband suppression.

A time-gated filter is demonstrated that converts a double-sideband radio-frequency (rf) waveform on a pulsed optically chirped carrier into a single sideband (SSB) waveform. Electrical technology to produce SSB modulation is currently limited to rfs less than 20 GHz, while our filter operates up to the maximum frequency available from optical modulators. Application of the filter in photonic time-stretch analog-to-digital converters (TS-ADCs) mitigates severe frequency fading owing to the dispersion penalty that limits the rf input signal bandwidth and time aperture.