Physical parameters, modeling, and methodological details in using IR laser pulses to warm frozen or vitrified cells ultra-rapidly

We report additional details of the thermal modeling, selection of the laser, and construction of the Cryo Jig used for our ultra-rapid warming studies of mouse oocytes (Jin et al., 2014). A Nd:YAG laser operating at 1064 nm was selected to deliver short 1ms pulses of sufficient power to produce a warming rate of 1×10(7)°C/min from -190°C to 0°C. A special Cryo Jig was designed and built to rapidly remove the sample from LN2 and expose it to the laser pulse. India ink carbon black particles were required to increase the laser energy absorption of the sample. The thermal model reported here is more general than that previously reported. The modeling reveals that the maximum warming rate achievable via external warming across the cell membrane is proportional to (1/R(2)) where R is the cell radius

On Mathematics, Imagination and the Beauty of Numbers

Mathematic

Survivals of mouse oocytes approach 100% after vitrification in 3-fold diluted media and ultra-rapid warming by an IR laser pulse

Vitrification is the most sought after route to the cryopreservation of animal embryos and oocytes and other cells of medical, genetic, and agricultural importance. Current thinking is that successful vitrification requires that cells be suspended in and permeated by high concentrations of protective solutes and that they be cooled at very high rates to below − 100°C. We report here that neither of these beliefs holds for mouse oocytes. Rather, we find that if mouse oocytes are suspended in media that produce considerable osmotic dehydration before vitrification and are subsequently warmed at ultra high rates (10,000,000°C/min) achieved by a laser pulse, nearly 100% will survive even when cooled rather slowly and when the concentration of solutes in the medium is only 1/3rd of standard

Personality profiles of young chess players

Although the game of chess has often featured in psychological research, we know very little about people who play chess, especially about children who take up chess as a hobby. This study presents the personality profiles as measured with the Big Five model (BFQ-C; Barbaranelli et al., 2003) of 219 young children who play chess and 50 of their peers who do not. Children who score higher on Intellect/openness and Energy/extraversion are more likely to play chess while children who score higher on Agreeableness are less likely to be attracted to chess. Boys with higher scores on Agreeableness are less likely to take up chess than boys with lower scores. Considering that girls score higher on Agreeableness, this factor may provide one of the possible reasons why more boys are interested in chess. Although none of the Big Five factors were associated with self-reported skill level, a sub-sample of 25 elite players had significantly higher scores on Intellect/openness than their weaker chess playing peers

Phase-coherent lightwave communications with frequency combs

Fiber-optical networks are a crucial telecommunication infrastructure in society. Wavelength division multiplexing allows for transmitting parallel data streams over the fiber bandwidth, and coherent detection enables the use of sophisticated modulation formats and electronic compensation of signal impairments. In the future, optical frequency combs may replace multiple lasers used for the different wavelength channels. We demonstrate two novel signal processing schemes that take advantage of the broadband phase coherence of optical frequency combs. This approach allows for a more efficient estimation and compensation of optical phase noise in coherent communication systems, which can significantly simplify the signal processing or increase the transmission performance. With further advances in space division multiplexing and chip-scale frequency comb sources, these findings pave the way for compact energy-efficient optical transceivers.Comment: 17 pages, 9 figure

Joint Superchannel Digital Signal Processing for Effective Inter-Channel Interference Cancellation

Modern optical communication systems transmit multiple frequency channels, each operating very close to its theoretical limit. The total bandwidth can reach 10 THz limited by the optical amplifiers. Maximizing spectral efficiency, the throughput per bandwidth is thus crucial. Replacing independent lasers with an optical frequency comb can enable very dense packing by overcoming relative drifts. However, to date, interference from non-ideal spectral shaping prevents exploiting the full potential of frequency combs. Here, we demonstrate comb-enabled multi-channel digital signal processing, which overcomes these limitations. Each channel is detected using an independent coherent receiver and processed at two samples-per-symbol. By accounting for the unique comb stability and exploiting aliasing in the design of the dynamic equalizer, we show that the optimal spectral shape changes, resulting in a higher signal-to-noise ratio that pushes the optimal symbol rate towards and even above the channel spacing, resulting in the first example of frequency-domain super-Nyquist transmission with multi-channel detection for optical systems. The scheme is verified both in back-to-back configuration and in single span transmission of a 21 channel superchannel originating from a 25 GHz-spaced frequency comb. By jointly processing three wavelength channels at a time, we achieve spectral efficiency beyond what is possible with independent channels. At the same time, one significantly relaxes the hardware requirements on digital-to-analog resolution and bandwidth, as well as filter tap numbers. Our results show that comb-enabled multi-channel processing can overcome the limitations of classical dense wavelength division multiplexing systems, enabling tighter spacing to make better use of the available spectrum in optical communications