Opto-Acoustic Oscillator Using Silicon Mems Optical Modulator

We show operation of a silicon MEMS based narrow-band optical modulator with large modulation depth by improving the electro-mechanical transducer. We demonstrate an application of the narrowband optical modulator as both the filter and optical modulator in an opto-electronic oscillator loop to obtain a 236.22 MHz Opto-Acoustic Oscillator (OAO) with phase noise of -68 dBc/Hz at 1 kHz offset

Phase Noise Modeling of Opto-Mechanical Oscillators

We build upon and derive a precise far from carrier phase noise model for radiation pressure driven opto-mechanical oscillators and show that calculations based on our model accurately match published phase noise data for such oscillators. Furthermore, we derive insights based on the equations presented and calculate phase noise for an array of coupled disk resonators, showing that it is possible to achieve phase noise as low as -80 dBc/Hz at 1 kHz offset for a 54 MHz opto-mechanical oscillator

A Monolithic Radiation-Pressure Driven, Low Phase Noise Silicon Nitride Opto-Mechanical Oscillator

Cavity opto-mechanics enabled radiation pressure (RP) driven oscillators shown in the past offer an all optical Radio Frequency (RF) source without the need for external electrical feedback. However these oscillators require external tapered fiber or prism coupling and non-standard fabrication processes. In this work, we present a CMOS compatible fabrication process to design high optical quality factor opto-mechanical resonators in silicon nitride. The ring resonators designed in this process demonstrate low phase noise RP driven oscillations. Using integrated grating couplers and waveguide to couple light to the micro-resonator eliminates 1/f^3 and other higher order phase noise slopes at close-to-carrier frequencies present in previous demonstrations. We present an RP driven OMO operating at 41.97MHz with a signal power of -11dBm and phase noise of -85dBc/Hz at 1kHz offset with only 1/f^2 noise down to 10Hz offset from carrier

Maternal effects on anogenital distance in a wild marmot population

Peer reviewedPublisher PD

Inhibiting ACK1-mediated phosphorylation of C-terminal Src kinase counteracts prostate cancer immune checkpoint blockade resistance

Solid tumours are highly refractory to immune checkpoint blockade (ICB) therapies due to the functional impairment of effector T cells and their inefficient trafficking to tumours. T-cell activation is negatively regulated by C-terminal Src kinase (CSK); however, the exact mechanism remains unknown. Here we show that the conserved oncogenic tyrosine kinase Activated CDC42 kinase 1 (ACK1) is able to phosphorylate CSK at Tyrosine 18 (pY18), which enhances CSK function, constraining T-cell activation. Mice deficient in the Tnk2 gene encoding Ack1, are characterized by diminished CSK Y18-phosphorylation and spontaneous activation of CD

Flavanols and Flavonols Content of Camellia sinensis with Different Maturity Stage Planted at Cameron Highland and Sabah Tea Plantation in Malaysia

This study was done to determine and compare the nutritional composition of ash, crude protein, crude fat and fiber, as well as the content of flavanols (EGCG, EGC, ECG and EC) and flavonols (quercetin and kaempferol) in tea planted in Cameron Highland (CH) and Sabah tea Plantation (ST) with different maturity stages (young, matured and old leaves). Young tea leaves in both CH and ST had the highest content of crude fat, protein and fiber and the values decreased as the leaves aged. Interestingly, crude protein content in all maturity stages of CH and ST were higher than in commercial tea (13.81%) with the range of 15.41 - 16.35% and 14.20 - 15.32% respectively. Meanwhile, ash content in ST (8.59 - 13.49%) was higher compared to CH (5.06 - 5.14%) and values decreased from young to old leaves. CH leaves had the highest moisture content (8.18 - 8.55%) followed by ST (5.23 - 9.20%), and commercial tea (5.7%). The order of flavanol in young leaves of CH and ST, and commercial tea leaves was ECG > EGCG > EGC > EC but for mature and old leaves the order was ECG > EGC > EGCG > EC with the only difference was in EGC and EGCG. The content of flavonol quercetin and kaempferol in CH were 3.51 mg/g and 4.05 mg/g respectively. Meanwhile, in ST leaves the values were 1.79 mg/g and 3.35 mg/g respectively, and both CH and ST showed that the highest content of flavonol was observed in young leaves and decreased as leaves aged