Effects of mobile phone radiation on the human central nervous system

The effects of mobile phone-like electromagnetic radiation on the human brain activity are examined. The research focuses on both radio frequency (RF) exposures and the much less studied low frequency (ELF) exposures (less than 40 kHz) arising from the battery operation of GSM handsets. The first single blind study recruited a small sample of twelve human volunteers. The eyes closed resting EEG activity is monitored after radio frequency exposure. With SAR levels of 2 W/kg, results reveal no statistical changes in any of the examined frequency bands for neither pulsed modulated RF signals nor continuous wave RF signals. In the second double blind study, a sample of 72 volunteers is recruited and an improved protocol comprised of separate pulsed RF, continuous RF and pulsed ELF exposures is employed. Exposures are delivered through a custom made handset capable of independent RF and ELF exposures. Findings include a reduced alpha band frequency activity during pulsed radio frequency and low frequency radiations exposures but no changes under the continuous RF radiation. Changes are present both during as well as after exposure, while greater changes are observed during exposures. The study of some non linear measures of the resting EEG revealed no changes under any of the active exposures. As the observed changes are very close to the normal EEG variation during resting conditions, their biological significance and health impact is not immediately obvious. However, their mere demonstration points to a low level interaction mechanism which may deserve further study

Polymer long-period raised rib waveguide gratings using nano-imprint lithography

This letter presents the fabrication and demonstration of a long-period raised rib waveguide grating using nano-imprint lithography. The device consists of a lower UV15 cladding, where relief-gratings are implemented, and an NOA73 raised rib core waveguide. Spectral transmission reveals a resonance at 1585 nm with about 10-dB rejection and 12-nm linewidth

The effect of GSM-like ELF radiation on the alpha band of the human resting EEG

Mobile phone handsets such as those operating in the GSM network emit extremely low frequency electromagnetic fields ranging from DC to at least 40 kHz. As a subpart of an extended protocol, the influence of these fields on the human resting EEG has been investigated in a fully counter balanced, double blind, cross-over design study that recruited 72 healthy volunteers. A decrease in the alpha frequency band was observed during the 20 minutes of ELF exposure in the exposed hemisphere only. This result suggests that ELF fields as emitted from GSM handsets during the DTX mode may have an effect on the resting alpha band of the human EEG

Translational neurophysiology in sheep:Measuring sleep and neurological dysfunction in CLN5 affected Batten disease sheep

This is the final published version of a paper originally published in BRAIN 2015: 138; 862?874, DOI: http://dx.doi.org/10.1093/brain/awv026Creating valid mouse models of slowly progressing human neurological diseases is challenging, not least because the short lifespan of rodents confounds realistic modelling of disease time course. With their large brains and long lives, sheep offer significant advantages for translational studies of human disease. Here we used normal and CLN5 Batten disease affected sheep to demonstrate the use of the species for studying neurological function in a model of human disease. We show that electroencephalography can be used in sheep, and that longitudinal recordings spanning many months are possible. This is the first time such an electroencephalography study has been performed in sheep. We characterized sleep in sheep, quantifying characteristic vigilance states and neurophysiological hallmarks such as sleep spindles. Mild sleep abnormalities and abnormal epileptiform waveforms were found in the electroencephalographies of Batten disease affected sheep. These abnormalities resemble the epileptiform activity seen in children with Batten disease and demonstrate the translational relevance of both the technique and the model. Given that both spontaneous and engineered sheep models of human neurodegenerative diseases already exist, sheep constitute a powerful species in which longitudinal in vivo studies can be conducted. This will advance our understanding of normal brain function and improve our capacity for translational research into neurological disorders.This work was funded by CHDI Inc. (AJM). Founding the\ud sheep flock, and costs in NZ relating to the rearing and\ud genotyping of the animals were funded by a series of grants\ud from the Neurological Foundation of NZ and the Batten\ud Disease Support and Research Association (DNP, NLM)

4 Tb/s Transmission Reach Enhancement Using 10 x 400 Gb/s Super-Channels and Polarization Insensitive Dual Band Optical Phase Conjugation

In this paper, we experimentally demonstrate the benefit of polarization insensitive dual-band optical phase conjugation for up to ten 400 Gb/s optical super-channels using a Raman amplified transmission link with a realistic span length of 75 km. We demonstrate that the resultant increase in transmission distance may be predicted analytically if the detrimental impacts of power asymmetry and polarization mode dispersion are taken into account

Variable carrier reduction in radio-over-fiber systems for increased modulation efficiencyusing a Si3N4 tunable extinction ratio ring resonator

This paper was published in OPTICS EXPRESS and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OE.20.025478 e. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law[EN] Variable optical carrier reduction via the use of a Si3N4 ring resonator notch filter with tunable extinction ratio is demonstrated in a 10 GHz radio-over-fiber system for improving the modulation efficiency. The extinction of the filter notch is tuned with micro-heaters, by setting the Mach-Zehnder coupler of the ring. Experimental results showing a modulation depth improvement of up to 20 dB are providedThis work was supported by the NANOCAP project A-1084-RT-GC that is coordinated by the European Defence Agency (EDA) and funded by 11 contributing Members (Cyprus, France, Germany, Greece, Hungary, Italy, Norway, Poland, Slovakia, Slovenia and Spain) in the framework of the Joint Investment Programme on Innovative Concepts and Emerging Technologies (JIP-ICET).Perentos, A.; Cuesta, F.; Rodrigo, M.; Canciamilla, A.; Vidal Rodriguez, B.; Pierno, L.; Griol Barres, A.... (2012). Variable carrier reduction in radio-over-fiber systems for increased modulation efficiencyusing a Si3N4 tunable extinction ratio ring resonator. Optics Express. 20(23):25478-25488. doi:10.1364/OE.20.025478S25478254882023Lim, C., Nirmalathas, A., Bakaul, M., Gamage, P., Ka-Lun Lee, Yizhuo Yang, … Waterhouse, R. (2010). Fiber-Wireless Networks and Subsystem Technologies. Journal of Lightwave Technology, 28(4), 390-405. doi:10.1109/jlt.2009.2031423Capmany, J., & Novak, D. (2007). Microwave photonics combines two worlds. Nature Photonics, 1(6), 319-330. doi:10.1038/nphoton.2007.89Gomes, N. J., Morant, M., Alphones, A., Cabon, B., Mitchell, J. E., Lethien, C., … Iezekiel, S. (2009). Radio-over-fiber transport for the support of wireless broadband services [Invited]. Journal of Optical Networking, 8(2), 156. doi:10.1364/jon.8.000156Williams, K. J., & Esman, R. D. (1994). Stimulated Brillouin scattering for improvement of microwave fibre-optic link efficiency. Electronics Letters, 30(23), 1965-1966. doi:10.1049/el:19941344Tonda-Goldstein, S., Dolfi, D., Huignard, J.-P., Charlet, G., & Chazelas, J. (2000). Stimulated Brillouin scattering for microwave signal modulation depth increase in optical links. Electronics Letters, 36(11), 944. doi:10.1049/el:20000723Hraimel, B., Zhang, X., Pei, Y., Wu, K., Liu, T., Xu, T., & Nie, Q. (2011). Optical Single-Sideband Modulation With Tunable Optical Carrier to Sideband Ratio in Radio Over Fiber Systems. Journal of Lightwave Technology, 29(5), 775-781. doi:10.1109/jlt.2011.2108261LaGasse, M. J., Hamilton, M. C., Charczenko, W., & Thaniyavarn, S. (1994). Optical carrier filtering for high dynamic range fibre optic links. Electronics Letters, 30(25), 2157-2158. doi:10.1049/el:19941422Esman, R. D., & Williams, K. J. (1995). Wideband efficiency improvement of fiber optic systems by carrier subtraction. IEEE Photonics Technology Letters, 7(2), 218-220. doi:10.1109/68.345928Attygalle, M., Lim, C., Pendock, G. J., Nirmalathas, A., & Edvell, G. (2005). Transmission improvement in fiber wireless links using fiber Bragg gratings. IEEE Photonics Technology Letters, 17(1), 190-192. doi:10.1109/lpt.2004.836901Lim, C., Attygalle, M., Nirmalathas, A., Novak, D., & Waterhouse, R. (2006). Analysis of optical carrier-to-sideband ratio for improving transmission performance in fiber-radio links. IEEE Transactions on Microwave Theory and Techniques, 54(5), 2181-2187. doi:10.1109/tmtt.2006.872809Barwicz, T., Popovic, M. A., Watts, M. R., Rakich, P. T., Ippen, E. P., & Smith, H. I. (2006). Fabrication of add-drop filters based on frequency-matched microring resonators. Journal of Lightwave Technology, 24(5), 2207-2218. doi:10.1109/jlt.2006.872298Ferrari, C., Canciamilla, A., Morichetti, F., Sorel, M., & Melloni, A. (2011). Penalty-free transmission in a silicon coupled resonator optical waveguide over the full C-band. Optics Letters, 36(19), 3948. doi:10.1364/ol.36.003948Gasulla, I., Lloret, J., Sancho, J., Sales, S., & Capmany, J. (2011). Recent Breakthroughs in Microwave Photonics. IEEE Photonics Journal, 3(2), 311-315. doi:10.1109/jphot.2011.2130517Capmany, J., Gasulla, I., & Sales, S. (2011). Harnessing slow light. Nature Photonics, 5(12), 731-733. doi:10.1038/nphoton.2011.290Kopp, C., Bernabé, S., Bakir, B. B., Fedeli, J., Orobtchouk, R., Schrank, F., … Tekin, T. (2011). Silicon Photonic Circuits: On-CMOS Integration, Fiber Optical Coupling, and Packaging. IEEE Journal of Selected Topics in Quantum Electronics, 17(3), 498-509. doi:10.1109/jstqe.2010.2071855Xu, D. W., Yoon, S. F., Tong, C. Z., Zhao, L. J., Ding, Y., & Fan, W. J. (2009). High-Temperature Continuous-Wave Single-Mode Operation of 1.3-$\mu$m p-Doped InAs–GaAs Quantum-Dot VCSELs. IEEE Photonics Technology Letters, 21(17), 1211-1213. doi:10.1109/lpt.2009.2024220Green, W. M. J., Lee, R. K., DeRose, G. A., Scherer, A., & Yariv, A. (2005). Hybrid InGaAsP-InP Mach-Zehnder Racetrack Resonator for Thermooptic Switching and Coupling Control. Optics Express, 13(5), 1651. doi:10.1364/opex.13.001651Li, C., Zhou, L., & Poon, A. W. (2007). Silicon microring carrier-injection-based modulators/switches with tunable extinction ratios and OR-logic switching by using waveguide cross-coupling. Optics Express, 15(8), 5069. doi:10.1364/oe.15.005069Espinola, R. L., Tsai, M. C., Yardley, J. T., & Osgood, R. M. (2003). Fast and low-power thermooptic switch on thin silicon-on-insulator. IEEE Photonics Technology Letters, 15(10), 1366-1368. doi:10.1109/lpt.2003.818246Barwicz, T., Popovic, M. A., Rakich, P. T., Watts, M. R., Haus, H. A., Ippen, E. P., & Smith, H. I. (2004). Microring-resonator-based add-drop filters in SiN: fabrication and analysis. Optics Express, 12(7), 1437. doi:10.1364/opex.12.00143

Ion beam etching of high resolution structures in Ta2O5 for grating-assisted directional coupler applications

An investigation on thin Ta2O5 films patterning using argon ion beam etching (IBE) is presented. The etch rates are characterised by varying the angle of incidence of the beam onto the substrate. Ta2O5 gratings with a period of 2.2 µm (1.1 µm linewidth) and 0.25 µm thickness are fabricated using an angle of incidence of 0°. The resulting Ta2O5 grating cross sectional profiles are analysed using AFM and SEM imaging. A fabrication method is thus demonstrated which could be used to implement wavelength selective gratings in applications such as grating-assisted directional couplers (GADCs)

An EEG investigation of sleep homeostasis in healthy and CLN5 Batten disease affected sheep

Sheep have large brains with human-like anatomy, making them a useful species for studying brain function. Sleep homeostasis has not been studied in sheep. Here, we establish correlates of sleep homeostasis in sheep through a sleep deprivation experiment. We then use these correlates to elucidate the nature of sleep deficits in a naturally occurring ovine model of neuronal ceroid lipofuscinosis (NCL, Batten disease) caused by a mutation in CLN5. In humans, mutations in this gene lead to cortical atrophy and blindness, as well as sleep abnormalities. We recorded electroencephalograms (EEGs) from unaffected and early stage CLN5−/− (homozygous, affected) sheep over 3 consecutive days, the second day being the sleep deprivation day. In unaffected sheep, sleep deprivation led to increased EEG delta (0.5– 4 Hz) power during non-rapid eye movement (NREM) sleep, increased time spent in the NREM sleep state, and increased NREM sleep bout length. CLN5−/− sheep showed comparable increases in time spent in NREM sleep and NREM sleep bout duration, verifying the presence of increased sleep pressure in both groups. Importantly, CLN5−/− sheep did not show the increase in NREM sleep delta power seen in unaffected sheep. This divergent delta power response is consistent with the known cortical degeneration in CLN5−/− sheep. We conclude that, whereas sleep homeostasis is present in CLN5−/− sheep, underlying CLN5−/− disease processes prevent its full expression, even at early stages. Such deficits may contribute to early abnormalities seen in sheep and patients and warrant further study

Translational neurophysiology in sheep: Measuring sleep and neurological dysfunction in CLN5 Batten disease affected sheep

Creating valid mouse models of slowly progressing human neurological diseases is challenging, not least because the short lifespan of rodents confounds realistic modelling of disease time course. With their large brains and long lives, sheep offer significant advantages for translational studies of human disease. Here we used normal and CLN5 Batten disease affected sheep to demonstrate the use of the species for studying neurological function in a model of human disease. We show that electroencephalography can be used in sheep, and that longitudinal recordings spanning many months are possible. This is the first time such an electroencephalography study has been performed in sheep. We characterized sleep in sheep, quantifying characteristic vigilance states and neurophysiological hallmarks such as sleep spindles. Mild sleep abnormalities and abnormal epileptiform waveforms were found in the electroencephalographies of Batten disease affected sheep. These abnormalities resemble the epileptiform activity seen in children with Batten disease and demonstrate the translational relevance of both the technique and the model. Given that both spontaneous and engineered sheep models of human neurodegenerative diseases already exist, sheep constitute a powerful species in which longitudinal in vivo studies can be conducted. This will advance our understanding of normal brain function and improve our capacity for translational research into neurological disorders