bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic wavelength calibration based on synchrosqueezed wavelet transform
Authors: Dang Hong , Tian Yuqi , Liu Huanhuan , Cheng Linqi , Chen Jinna , Feng Kunpeng , Cui Jiwen , Shum Perry Ping
Published: November 2022

With the developments of the tunable laser source (TLS), there are increasing demands for high-resolution dynamic wavelength calibration in recent years. Considering mutual constraints between wide measurement range and high calibration resolution, we propose a dynamic wavelength calibration method based on an auxiliary Mach-Zehnder interferometer (MZI) and the synchrosqueezed wavelet transform (SSWT). Our proposed method can achieve a calibration resolution of 5 fm and a tuning range of 10 nm. Moreover, the measurement range and spatial resolution of the optical frequency domain reflectometer (OFDR) system are improved to ∼80 m and ∼mm, respectively. Our proposed approach can substantially reduce the subtle spectrum distortion (tens of fm) in coherent optical spectrum analyzer (COSA) systems.
Long-range and high-resolution traffic monitoring based on pulse-compression DAS and advanced vehicle tracking algorithm
Authors: Corera Iñigo , Piñeiro Enrique , Navallas Javier , Sagues Mikel , Loayssa Alayn
Published: November 2022

We demonstrate traffic monitoring over tens of kilometres of road using an enhanced distributed acoustic sensing system based on optical pulse compression and a novel transformed-domain-based processing scheme with enhanced vehicle detection and tracking capabilities.
OCDR-Based Measurement of Polarization States
Authors: Noda Kohei , Lee Heeyoung , Nakamura Kentaro , Mizuno Yosuke
Published: November 2022

We propose a new scheme for polarization-sensitive distributed fiber-optic sensing, termed as polarization optical correlation-domain reflectometry (POCDR). We experimentally demonstrate its fundamental operations by measuring full states of polarization.
Noise Floor Analysis and Compensation in Long-Range ESA-Free Optical Correlation-Domain Reflectometry
Authors: Miyamae Tomoya , Zhu Guangtao , Noda Kohei , Lee Heeyoung , Nakamura Kentaro , Mizuno Yosuke
Published: November 2022

We experimentally analyze the distorted noise floor peculiar to the kilometer-order range distributed reflectivity measurement by high-speed optical correlation-domain reflectometry. We also show that this noise floor can be compensated by appropriate filtering.
Distributed Strain Analysis of a Quadrupolar Fiber-Optic Gyroscope Coil by Brillouin-OTDA and Rayleigh-OFDR
Authors: Boiron Hugo , Pillon Jérémie , Peter Emmanuelle , Rattier Maxime , Marin Emmanuel , Morana Adriana , Collignon Matthieu , Girard Sylvain , Lefèvre Hervé C.
Published: November 2022

Brillouin-Optical Time Domain Analysis and Rayleigh-Optical Frequency Domain Reflectometry, are exploited to improve the understanding of the longitudinal strain distribution along the optical fiber of a quadrupolar sensing coil of a fiber-optic gyroscope.
Real-time cytotoxicity monitoring using microcavity in-line Mach-Zehnder interferometer
Authors: Gabler Tomasz , Janik Monika , Koba Marcin , Sosnowska Malwina , Kutwin Marta , Chwalibóg Ewa Sawosz , Śmietana Mateusz
Published: November 2022

The work reports a microcavity in-line Mach-Zehnder interferometer sensor for real-time, label-free monitoring of a non-cancer bone marrow stromal cell line HS-5 responses to two cytotoxic agents, namely dimethyl sulfoxide (DMSO) and hydrogen peroxide (H2O2).
Distributed temperature measurement for battery thermal runaway with frequency-resolved-multiplex OFDR
Authors: Guo Zhen , Han Gaoce , Yan Jize , Greenwood David , Marco James , Yu Yifei
Published: November 2022

Frequency-resolved multiplex is proposed for both high resolution and fast measurement in the optical frequency domain reflectometer. 100 Hz measurement with 2 cm sensing resolution is experimentally verified for thermal runaway monitoring in battery system.
Performance Analysis of Gaussian Process Regression in the Temperature Estimation of Fiber Bragg Grating Sensors
Authors: Martín Sebastián San , Soto Marcelo A.
Published: November 2022

The performance of Gaussian process regression for temperature estimation using fiber Bragg grating sensors is investigated. Using experiment- and simulation-based training, the estimated temperature uncertainty (standard deviation) and offset are analyzed versus different measurement parameters.
Demodulation Scheme with Low Harmonic Distortion for PMDI-TDM Based Fiber-Optic Sensor Array
Authors: Zhang Jianxiang , Cheng Kun , Huang Wenzhu , Zhang Wentao , Li Fang
Published: November 2022

An improved demodulation scheme is proposed for PMDI-TDM based fiber-optic sensor array, which tracks the parameters of the interference fringes using the multichannel parallel EKF, can effectively suppress the harmonic distortion of the sensor array.
Analytical prediction of the final error due to noise in a ϕ-OTDR system
Authors: Yang Yuting , Galal Malak , Sebastian Suneetha , Zhang Li , Thévenaz Luc
Published: November 2022

An analytical expression to estimate the uncertainty on the frequency shift in ϕ-OTDR systems is established and confirmed by actual data.
Analyzing the coding gain of coded Raman optical time-domain reflectometry
Authors: Li Xin , Yang Zhisheng , Hong Xiaobin , Wu Jian
Published: November 2022

The signal-to-noise ratios of single-pulse and coded Raman optical time-domain reflectometry (ROTDR) are analytically modelled. It turns out that there is an upper limit of coding gain of ~9 dB imposed by amplified shot noise in coded ROTDR.
Minimizing the measurement time of frequency-scanned phase-sensitive OTDR enabled by sinc interpolation
Authors: Zhang Qian , Yang Zhisheng , Hong Xiaobin , Gao Xia , Wu Jian
Published: November 2022

Design rules for minimizing the measurement time of frequency-scanned phase-sensitive optical time-domain reflectometry (Φ-OTDR) are addressed, enabling to achieve the shortest possible measurement time without large errors nor systematical errors.
High-speed FBG interrogator based on FPGA-controlled fiber interferometer
Authors: Elaskar Javier , Ayaz Rana M. A. , Tozzetti Lorenzo , Luda Marcelo , Di Pasquale Fabrizio , Oton Claudio J.
Published: November 2022

We report FBG interrogation measurements up to 1MS/s using a polarization-maintaining-fiber-based Sagnac interferometer monitored in real time with an FPGA system. The system has lower noise levels than commercial interrogators.
Three-components fiber-optic quasi-distributed acoustic sensing (3C-QDAS)
Authors: Zhang Lixia , Jing Qiang , Han Bing , Rao Yunjiang , Li Wenhui , Xin Peilian , Yang Tianyuan , Gong Yuan , Ran Zengling , Shao Tianqi
Published: November 2022

We verify a novel three-components fiber-optic quasi-distributed acoustic sensing concept (3C-QDAS) based on DAS technology for detection of vector strains applied to optical fibers mounted on elastomers by an acoustic source, for the first time.
Multiplexed Fiber Bragg Grating Sensors for In-Pile Measurements in Nuclear Reactor Cores
Authors: Wu Jingyu , Wang Mohan , Cao Rongtao , Carpenter David , Zheng Guiqiu , Rountree Steven Derek , Li Mingjun , Chen Kevin P.
Published: November 2022

This paper reports in-pile testing of multiplexed Type-II fiber Bragg gratings by femtosecond laser in radiation-hardened fibers in MIT research reactor with a total neutron fluence of 1020 n/cm2 at temperature up to 560 ℃.
Highly Accurate 3D Shape Sensing Based on Special Fiber OFDR System Assisted with ICP Algorithm
Authors: Lv Yuejuan , Li Honglin , Yang Ziyun , Yan Zhijun , Zang Jianfeng , Sun Qizhen
Published: November 2022

A highly accurate 3D shape sensing scheme based on special fiber OFDR is proposed and demonstrated. Combining with ICP algorithm, the maximum reconstruction error is effectively reduced to 0.29% within a length of 200 mm.
Single Channel Multicore Fiber Assemblies Applied to Twist Effects in Fiber Shape Sensing
Authors: Ko Wing , Feder Kenneth S. , Sun Xiaoguang , Li Jie , Westbrook Paul S.
Published: November 2022

We demonstrate high spatial resolution fiber shape sensing using one simultaneous measurement of four helically twisted cores, allowing calibration of the fiber spin rate. Our fiber is also shown to have minimal induced mechanical twist.
Distributed Fiber-optic Sensing, Structural Monitoring and Control System for Aircraft
Authors: Wada Daichi , Igawa Hirotaka , Arizono Hitoshi , Sano Yoichi
Published: November 2022

A concept of distributed fiber-optic sensing, monitoring and control for smart aircraft is introduced. In-flight sensing results are shown with comparison to aeroelastic analysis. Aerodynamic load identification is also conducted.
Ultra-long large-capacity FBG sensing with hybrid random lasing amplification and deep-learning spectrum denoising
Authors: Yang Ze-Yuan , Liu Jie , Han Bing , Wang Zi-Nan , Dong Shi-Sheng , Rao Yun-Jiang
Published: November 2022

This paper presents a novel single-ended ultra-long (150km) large-capacity (>300) FBG sensing system that adopts hybrid high-order random lasing amplification and deep-learning spectrum denoising for practical use in safety monitoring of long-haul powerlines.
Long range, wide bandwidth, and rapid optical frequency domain reflectometry employing concatenative referencing method
Authors: Tanimura Daiki , Miyake Daiki , Zhang Chao , Ito Fumihiko , Yoshimura Yuichi , Aoshika Hiroyuki , Imai Michio
Published: November 2022

Long range strain measurement is presented by OFDR employing wide and rapid wavelength swept light source. The measurement range of ~1000 µε with µε-level accuracy is achieved over 140 m, potentially at 150 Hz.
High-performance and low-cost FBG strain sensor demodulation system assisted by artificial neural network algorithm
Authors: Chen Shengchao , Yao Feifan , Ren Sufen , Yang Jianli , Yang Qian , Wang Guanjun , Huang Mengxing
Published: November 2022

A high-performance, low-cost FBG strain sensor demodulation system was studied, which can achieve ± 6 pm central wavelength interrogation precision without an optical spectrum analyzer, and with favorable repeatability.
High-sensitive Intensity Modulated Curvature Sensor Based on D-shaped Fiber Wrapped in PDMS Film
Authors: Li Fei , Wen Yaqi , Wan Kai , Feng Fanbu , Sun Bing , Zhou Kaiming
Published: November 2022

The curvature sensor, which consists of wrapping the coreless D-shaped optical fiber in polydimethylsiloxane (PDMS) film is experimentally proposed. High-sensitive curvature measurements are achieved with sensitivities of 2.04 dB/m−1 and 2.66 dB/m−1 in the X+ and X− direction, respectively. Moreover, the proposed sensor demonstrates a low temperature dependence of 0.025 dB/°C.
Multi-source Separation for Fiber-Optic Distributed Acoustic Sensor (DAS)
Authors: Liu Yimeng , Tu Yunlin , Sun Yuwen , Yao Lishuang , Wu Huijuan , Rao Yunjiang
Published: November 2022

To improve the detection and recognition performance of DAS in complicated multi-source interfering environments, a blind multi-source separation method is proposed based on the FastICA, which utilizes the independency and non-Gaussianity of different sources.
Two-Dimensional (2-D) Localization Method of Ground Vibration Source with Fiber-Optic Distributed Acoustic Sensors (DAS)
Authors: Wang Yufeng , Liu Xinyu , Sun Yuwen , Liu Liang , Tu Yunlin , Wu Huijuan , Rao Yunjiang
Published: November 2022

2-D localization of ground vibration for DAS is realized by extracting the spatial attenuation feature and mapping its relationship with the radial distances by a deep learning network. Field tests prove its effectiveness.
Non-invasive pipeline pressure monitoring based on Intrinsic Fabry-Perot interferometers
Authors: Li Yuqi , Wang Qirui , Wright Ruishu , Lalam Nageswara Rao , Diemler Nathan , Hawley Adam G. , Chen Kevin P.
Published: November 2022

This paper demonstrates a non-invasive pipeline pressure monitoring using intrinsic Fabry-Perot interferometer (IFPI) fiber optic sensors. Fiber sensors installed outside the pipe can achieve 2% pressure measurement accuracy from 15 psi to 1000 psi.
Fiber Bragg Grating Sensors for Monitoring Railway Switches and Crossings
Authors: Kerouche Abdelfateh , Najeh Taoufik , Jaen-Sola Pablo
Published: November 2022

A solution to monitor excessive wear on railway switches and crossings based on Fiber Brag Grating (FBG) optical fiber sensors is discussed. Results of this pilot study based on simulation and lab tests have shown correlation for static load.
High-Speed Interrogation of Embedded Fiber Bragg Grating (FBG) Sensors Fabricated by Ultrasonic Additive Manufacturing
Authors: Zhao Jieru , Li Yuqi , Zhao Kehao , Wang Qirui , Swinehart Philips , Jewart Charles , Petrie Chris , Chen Kevin P.
Published: November 2022

We present embedded FBG sensors fabricated by ultrasonic additive manufacturing process as a package method for FBG strain sensors. The vibration induced dynamic strain is interrogated by a tunable VCSEL enabled high-speed interrogation system.
Pipeline Degradation Evaluation Based on Distributed Fiber Sensors and Convolutional Neural Networks (CNNs)
Authors: Wu Zekun , Wang Qirui , Gribok Andrei V. , Chen Kevin P.
Published: November 2022

We present a machine learning method to analyze data harnessed by distributed fiber sensors for pipeline monitoring. Convolutional neural networks are used to identify and classify pipeline internal defects with 99% and 94% accuracy, respectively.
Fully Continuous Fiber-optic Hydrophone Streamer with Small Channel Spacing for Marine Seismic Acquisition
Authors: Chen Junfeng , Li Hao , Xiao Xiangpeng , Fan Cunzheng , Wen Pengfei , Yan Zhijun , Sun Qizhen
Published: November 2022

We demonstrate a fully continuous fiber-optic streamer with small channel spacing of ≤ 1m and ultra-high sensitivity of −137 dB rerad/(μPa·m), whose field test exhibits tremendous potential for the marine seismic acquisition.
Development of a water flow and velocity optical fiber sensor for field testing
Authors: Rodriguez-Rodriguez A. , Urroz J.C. , Dieguez P.M. , Bravo M. , Lopez-Amo M. , Lopez J.J.
Published: November 2022

A water flow and velocity fiber optic sensor system was developed and tested. The sensing head was especially developed and ruggedized to measure velocities at different depths, in order to calculate the discharge in channels.
Electric field sensor based on thin film lithium niobate
Authors: Toroghi Seyfollah , Rabiei Payam
Published: November 2022

Thin film lithium niobate based electric field sensing is demonstrated using both micro-ring and Mach-Zehnder modulators. A high sensitivity of 80 mV/(m.Hz1/2) and of 2.2 V/(m.Hz1/2) is achieved using micro-ring modulators and Mach-Zehnder modulators, respectively.
fs-IR laser point-by-point inscription of Fiber Bragg Gratings for a new generation of miniature sensors using novel 25µm diameter optical fibers
Authors: Leyssner Felix , Myumyun Erray , Meijer Eric , Knoppers Rik , Daugherty Tim , Stoker Anne , Claesson Åsa , Nieuwland Remco
Published: November 2022

fs-point-by-point through the coating written FBGs as a basis for novel sensor concepts using 25µm optical fiber. fs-point-by-point FBGs in novel single mode fiber with a cladding diameter of 25µm have been produced in fiber that is 5 times smaller than conventional telecommunication optical fiber. The development opens the path to new sensor types including miniature pressure sensors with a diameter of only 330µm (1Fr.)
Multiplexed Active Fiber Bragg Grating Sensor Array Induced by Femtosecond Laser
Authors: Zhao Kehao , Huang Sheng , Wright Ruishu , Chen Kevin P.
Published: November 2022

This paper describes a method to fabricate multiplexed active fiber sensor array enabled by femtosecond laser-induced nano-scattering centers. Light scattered from laser-induced scattering centers is harnessed by on-fiber coating for active measurements.
Novel light coupling structure for excitation of whispering gallery modes in microsphere resonators based on an etched PMMA capillary
Authors: Wang Zhuochen , Wang Zhe , Rout Anuradha , Semenova Yuliya
Published: November 2022

A novel approach to excitation of whispering gallery modes in microsphere resonators is proposed and demonstrated experimentally. The proposed structure realizes light coupling through the circular peripheral contact between the microsphere and supporting capillary wall.
Temperature stability of a polarimetric current sensor based on BSO crystal fluorescence
Authors: Eftimov Tinko , Dyankov Georgi , Arapova Alla , Kolev Petar , Vladev Veselin
Published: November 2022

A simple spectrally interrogated polarimetric current sensor based on BSO crystal fluorescence is reported. The sensitivity to current is 0.0718 nm/A to 0.13 nm/A to temperature between -0.016 nm/deg and - 0.08 nm/deg.
Broadband polarization-entangled source for C+L-band flex-grid quantum networks
Authors: Alshowkan Muneer , Lukens Joseph M. , Lu Hsuan-Hao , Kirby Brian T. , Williams Brian P. , Grice Warren P. , Peters Nicholas A.
Published: November 2022

The rising demand for transmission capacity in optical networks has motivated steady interest in expansion beyond the standard C-band (1530–1565 nm) into the adjacent L-band (1565–1625 nm) for an approximate doubling of capacity in a single stroke. However, in the context of quantum networking, the L-band has yet to be fully leveraged with the suite of advanced tools for characterization and management available from classical lightwave communications. In this work, we demonstrate an ultrabroadband two-photon source integrating both C- and L-band wavelength-selective switches for complete control of spectral routing and allocation across 7.5 THz in a single setup. Polarization state tomography of all 150 pairs of 25-GHz-wide channels reveals an average fidelity of 0.98 and total distillable entanglement greater than 181 kebits/s. This source is explicitly designed for flex-grid optical networks and can facilitate optimal utilization of entanglement resources across the full C+L-band.
Optimized computer-generated hologram for enhancing depth cue based on complex amplitude modulation
Authors: Pi Dapu , Liu Juan , Wang Jie , Sun Yutong , Yang Yan , Zhao Weirui , Wang Yongtian
Published: November 2022

In this Letter, we introduce a computer-generated hologram (CGH) optimization method to enhance the depth cue based on complex amplitude modulation (CAM). An iterative algorithm is designed to generate the optimized random phase (ORAP) according to the size of the target image and the bandwidth limitation condition. The ORAP with limited bandwidth is used as the initial phase of the target image and the hologram is encoded based on the analytical formula. Our proposal can maintain the advantages of CAM and achieve holographic three-dimensional (3D) display with an enhanced depth cue. It is expected that the proposed method could be widely used in holographic field in the future.
Analog wavelet-like transform based on stimulated Brillouin scattering
Authors: Zuo Pengcheng , Ma Dong , Chen Yang
Published: November 2022

A photonics-enabled analog wavelet-like transform system, characterized by multiscale time-frequency analysis (TFA), is proposed based on a typical stimulated Brillouin scattering (SBS) pump–probe setup using an optical nonlinear frequency-sweep signal. The periodic SBS-based frequency-to-time mapping (FTTM) is implemented by using a periodic nonlinear frequency-sweep optical signal with a time-varying chirp rate. The frequency-domain information of the signal under test (SUT) in different periods is mapped to the time domain via the FTTM in the form of low-speed electrical pulses, which is then spliced to analyze the time-frequency relationship of the SUT in real-time. The time-varying chirp rate in each sweep period makes the signals with different frequencies have different frequency resolutions in the FTTM process, which is very similar to the characteristics of the wavelet transform, so we call it a wavelet-like transform. An experiment is carried out. Multiscale TFA of a variety of RF signals is carried out in a 4-GHz bandwidth limited only by the equipment.
Seeing the strong suppression of higher order modes in single trench fiber using the S2 technique
Authors: An Yi , Yang Huan , Chen Xiao , Huang Liangjin , Yan Zhiping , Pan Zhiyong , Wang Zefeng , Jiang Zongfu , Zhou Pu
Published: November 2022

The single trench fiber (STF) is a promising fiber design for mode area scaling and higher order mode (HOM) suppression. In this Letter, we experimentally demonstrate the strong HOM-suppression in a homemade STF using the spatially and spectrally resolved imaging (S2) technique. This STF has a 20-µm core and its performance is compared to a conventional step-index fiber with almost the same parameter. Results show that the bending loss of the HOM in STF is 8-times larger than conventional fiber at a bend radius of 7 cm. In addition, when severe coupling mismatch is introduced at the input end of the fiber, the STF can keep the fundamental-mode output while the conventional fiber cannot. To the best of our knowledge, this is the first time to experimentally analyze the HOM content in an STF and compare its performance with that of a conventional fiber. Our results indicate the great potential of the STF for filtering the HOM in fiber laser applications.
Thermally switchable, bifunctional, scalable, mid-infrared metasurfaces with VO2 grids capable of versatile polarization manipulation and asymmetric transmission
Authors: Serebryannikov Andriy E. , Lakhtakia Akhlesh , Ozbay Ekmel
Published: November 2022

We conceptualized three-array scalable bifunctional metasurfaces comprising only three thin strip grids and numerically determined their characteristics in the mid-infrared spectral regime for switchable operation scenarios involving polarization manipulation and related diodelike asymmetric transmission (AT) as one of two functionalities. A few or all of the grids were taken to be made of VO2, a bifunctionality-enabling phase-change material; there are no layers and/or meta-atoms comprising simultaneously both metal and VO2. For each proposed metasurface, two effective structures and, therefore, two different functionalities exist, corresponding to the metallic and insulating phases of VO2. The achieved scenarios of functionality switching significantly depend on the way in which VO2 is incorporated into the metasurface. Switchable bands of polarization manipulation are up to 40 THz wide. The AT band can be modulated when Fabry–Perot (anti-) resonances come into play. Besides, transmission regimes with the cross-polarized component insensitive to VO2 phase change are possible, as well as the ones with all co- and cross-polarized components having the same magnitude for both linear polarizations of the incident wave.
Broadband THz wave generation in organic benzothiazolium crystals at MHz repetition rates [Invited]
Authors: Puc Uros , Yang Jeong-A , Kim Deokjoong , Kwon O-Pil , Jazbinsek Mojca
Published: November 2022

We present broadband terahertz wave generation based on benzothiazolium crystals at a 100 MHz repetition rate. Among various benzothiazolium crystals, we chose PMB-4TFS (2-(4-(4-(hydroxymethyl)piperidin-1-yl)styryl)-3-methylbenzothiazol-3-ium 4-(trifluorome-thyl)benzenesulfonate) due to its large macroscopic optical nonlinearity, good crystal characteristics, and suppressed molecular phonon vibrations. When pumped at the telecommunication wavelength of 1560 nm, the generated THz spectrum covers up to ∼15 THz and the corresponding THz amplitude for a 0.29 mm thick crystal at normal incidence is by more than one order of magnitude higher compared to the inorganic standard, 1.0 mm thick ZnTe generator crystal.
Glasses in a Fraction of a Second
Authors: Sundaram S.K.
Published: November 2022

The development of ultrafast lasers has revolutionized the study
and processing of glasses, enabling new applications and drawing closer to
a full understanding of the liquid-to-glass transition.
The Nonreciprocal Adventures of Light
Authors: Boriskina Svetlana V. , Blevins Morgan , Pajovic Simo
Published: November 2022

Reciprocity of light and energy transport is not a fundamental
law—and breaking it can enable the “one-way” flow of
optical energy, unlocking applications in energy harvesting, signal
processing and thermal-emission control.
Tunable THz flat zone plate based on stretchable single-walled carbon nanotube thin film
Authors: Katyba Gleb M. , Raginov Nikita I. , Khabushev Eldar M. , Zhelnov Vladislav A. , Gorodetsky Andrei , Ghazaryan Davit A. , Mironov Mikhail S. , Krasnikov Dmitriy V. , Gladush Yuri G. , Lloyd-Hughes James , Nasibulin Albert G. , Arsenin Aleksey V. , Volkov Valentyn S. , Zaytsev Kirill I. , Burdanova Maria G.
Published: November 2022

Tunable optoelectronics have attracted a lot of attention in recent years because of their variety of applications in next-generation devices. Among the potential uses for tuning optical elements, those allowing consistent parameter control stand out. We present an approach for the creation of mechanically tunable zone plate lenses in the THz range. Our devices comprise single-walled carbon nanotube (SWCNT) thin films of predetermined design integrated with stretchable polymer films. These offer high-performance and in situ tunability of focal length up to 50%. We studied the focusing properties of our lenses using the backward-wave oscillator THz imaging technique, supported by numerical simulations based on the finite element frequency domain method. Our approach may further enable the integration of SWCNT films into photonic and optoelectronic applications and could be of use for the creation of a variety of flexible and stretchable THz optical elements.
O-GlcNAc transferase plays a non-catalytic role in C. elegans male fertility
Authors: Konzman Daniel , Fukushige Tetsunari , Dagnachew Mesgana , Krause Michael , Hanover John A.
Published: November 2022

Animal behavior is influenced by the competing drives to maintain energy and to reproduce. The balance between these evolutionary pressures and how nutrient signaling pathways intersect with mating remains unclear. The nutrient sensor O-GlcNAc transferase, which post-translationally modifies intracellular proteins with a single monosaccharide, is responsive to cellular nutrient status and regulates diverse biological processes. Though essential in most metazoans, O-GlcNAc transferase (ogt-1) is dispensable in Caenorhabditis elegans, allowing genetic analysis of its physiological roles. Compared to control, ogt-1 males had a four-fold reduction in mean offspring, with nearly two thirds producing zero progeny. Interestingly, we found that ogt-1 males transferred sperm less often, and virgin males had reduced sperm count. ogt-1 males were also less likely to engage in mate-searching and mate-response behaviors. Surprisingly, we found normal fertility for males with hypodermal expression of ogt-1 and for ogt-1 strains with catalytic-dead mutations. This suggests OGT-1 serves a non-catalytic function in the hypodermis impacting male fertility and mating behavior. This study builds upon research on the nutrient sensor O-GlcNAc transferase and demonstrates a role it plays in the interplay between the evolutionary drives for reproduction and survival.
A robust and adaptive framework for interaction testing in quantitative traits between multiple genetic loci and exposure variables
Authors: Hecker Julian , Prokopenko Dmitry , Moll Matthew , Lee Sanghun , Kim Wonji , Qiao Dandi , Voorhies Kirsten , Kim Woori , Vansteelandt Stijn , Hobbs Brian D. , Cho Michael H. , Silverman Edwin K. , Lutz Sharon M. , DeMeo Dawn L. , Weiss Scott T. , Lange Christoph
Published: November 2022

The identification and understanding of gene-environment interactions can provide insights into the pathways and mechanisms underlying complex diseases. However, testing for gene-environment interaction remains a challenge since a.) statistical power is often limited and b.) modeling of environmental effects is nontrivial and such model misspecifications can lead to false positive interaction findings. To address the lack of statistical power, recent methods aim to identify interactions on an aggregated level using, for example, polygenic risk scores. While this strategy can increase the power to detect interactions, identifying contributing genes and pathways is difficult based on these relatively global results. Here, we propose RITSS (Robust Interaction Testing using Sample Splitting), a gene-environment interaction testing framework for quantitative traits that is based on sample splitting and robust test statistics. RITSS can incorporate sets of genetic variants and/or multiple environmental factors. Based on the user’s choice of statistical/machine learning approaches, a screening step selects and combines potential interactions into scores with improved interpretability. In the testing step, the application of robust statistics minimizes the susceptibility to main effect misspecifications. Using extensive simulation studies, we demonstrate that RITSS controls the type 1 error rate in a wide range of scenarios, and we show how the screening strategy influences statistical power. In an application to lung function phenotypes and human height in the UK Biobank, RITSS identified highly significant interactions based on subcomponents of genetic risk scores. While the contributing single variant interaction signals are weak, our results indicate interaction patterns that result in strong aggregated effects, providing potential insights into underlying gene-environment interaction mechanisms.
Characterization of hepatitis B viral forms from patient plasma using velocity gradient: Evidence for an excess of capsids in fractions enriched in Dane particles
Authors: Pronier Charlotte , Bomo Jérémy , Besombes Juliette , Genet Valentine , Laperche Syria , Gripon Philippe , Thibault Vincent
Published: November 2022

Hepatitis B virus (HBV) morphogenesis is characterized by a large over-production of subviral particles and recently described new forms in parallel of complete viral particles (VP). This study was designed to depict circulating viral forms in HBV infected patient plasmas, using velocity gradients and most sensitive viral markers. Plasmas from chronic hepatitis B (CHB) patients, HBeAg positive or negative, genotype D or E, were fractionated on velocity and equilibrium gradients with or without detergent treatment. Antigenic and molecular markers were measured in plasma and in each collected fraction. Fast Nycodenz velocity gradients revealed good reproducibility and provided additional information to standard equilibrium sucrose gradients. HBV-RNAs circulated as enveloped particles in all plasmas, except one, and at lesser concentrations than VP. Calculations based on standardized measurements and relative virion and subviral particle molecular stoichiometry allowed to refine the experimental approach. For the HBeAg-positive plasma, VP were accompanied by an overproduction of enveloped capsids, either containing HBs, likely corresponding to empty virions, or for the main part, devoid of this viral envelope protein. Similarly, in the HBeAg-negative sample, HBs enveloped capsids, likely corresponding to empty virions, were detected and the presence of enveloped capsids devoid of HBs protein was suspected but not clearly evidenced due to the presence of contaminating high-density subviral particles. While HBeAg largely influences HBcrAg measurement and accounts for two-thirds of HBcrAg reactivity in HBeAg-positive patients, it remains a 10 times more sensitive marker than HBsAg to characterize VP containing fractions. Using Nycodenz velocity gradients and standardized biomarkers, our study proposes a detailed characterization of circulating viral forms in chronically HBV infected patients. We provide evidence for an excess of capsids in fractions enriched in Dane particles, likely due to the presence of empty virions but also by capsids enveloped by an HBs free lipid layer. Identification of this new circulating viral particle sets the basis for studies around the potential role of these entities in hepatitis B pathogeny and their physiological regulation.
The small RNA landscape is stable with age and resistant to loss of dFOXO signaling in Drosophila
Authors: Gartland Siobhan , Zeng Baosheng , Marr Michael T.
Published: November 2022

Aging can be defined as the progressive loss of physiological homeostasis that leads to a decline in cellular and organismal function. In recent years, it has become clear that small RNA pathways play a role in aging and aging related phenotypes. Small RNA pathways regulate many important processes including development, cellular physiology, and innate immunity. The pathways illicit a form of posttranscriptional gene regulation that relies on small RNAs bound by the protein components of the RNA-induced silencing complexes (RISCs), which inhibit the expression of complementary RNAs. In Drosophila melanogaster, Argonaute 1 (Ago1) is the core RISC component in microRNA (miRNA) silencing, while Argonaute 2 (Ago2) is the core RISC component in small interfering RNA (siRNA) silencing. The expression of Ago1 and Ago2 is regulated by stress response transcription factor Forkhead box O (dFOXO) increasing siRNA silencing efficiency. dFOXO plays a role in multiple stress responses and regulates pathways important for longevity. Here we use a next-generation sequencing approach to determine the effects of aging on small RNA abundance and RISC loading in male and female Drosophila. In addition, we examine the impact of the loss of dFOXO on these processes. We find that the relative abundance of the majority of small RNAs does not change with age. Additionally, under normal growth conditions, the loss of dFOXO has little effect on the small RNA landscape. However, we observed that age affects loading into RISC for a small number of miRNAs.
Getting rid of ‘rain’ and ‘stars’: Mitigating inhibition effects on ddPCR data analysis, the case study of the invasive crayfish Pacifastacus leniusculus in the streams of Luxembourg
Authors: Porco David , Hermant Sylvie , Purnomo Chanistya Ayu , Horn Mario , Marson Guy , Colling Guy
Published: November 2022

ddPCR is becoming one of the most widely used tool in the field of eDNA-based aquatic monitoring. Although emulsion PCR used in ddPCR confers a partial mitigation to inhibition due to the high number of reactions for a single sample (between 10K and 20K), it is not impervious to it. Our results showed that inhibition impacts the amplitude of fluorescence in positive droplets with a different intensity among rivers. This signal fluctuation could jeopardize the use of a shared threshold among samples from different origin, and thus the accurate assignment of the positive droplets which is particularly important for low concentration samples such as eDNA ones: amplification events are scarce, thus their objective discrimination as positive is crucial. Another issue, related to target low concentration, is the artifactual generation of high fluorescence droplets (‘stars’). Indeed, these could be counted as positive with a single threshold solution, which in turn could produce false positive and incorrect target concentration assessments. Approximating the positive and negative droplets distribution as normal, we proposed here a double threshold method accounting for both high fluorescence droplets (‘stars’) and PCR inhibition impact in delineating positive droplets clouds. In the context of low concentration template recovered from environmental samples, the application of this method of double threshold establishment could allow for a consistent sorting of the positive and negative droplets throughout ddPCR data generated from samples with varying levels of inhibitor contents. Due to low concentrations template and inhibition effects, Quantasoft software produced an important number of false negatives and positive comparatively to the double threshold method developed here. This case study allowed the detection of the invasive crayfish P. leniusculus in 32 out of 34 sampled sites from two main rivers (Alzette and Sûre) and five of their tributaries (Eisch, Attert, Mamer, Wiltz and Clerve).
Harmonic radar tracking of individual melon flies, Zeugodacus cucurbitae, in Hawaii: Determining movement parameters in cage and field settings
Authors: Miller Nicole D. , Yoder Theodore J. , Manoukis Nicholas C. , Carvalho Lori A. F. N. , Siderhurst Matthew S.
Published: November 2022

Tephritid fruit flies, such as the melon fly,Zeugodacus cucurbitae, are major horticultural pests worldwide and pose invasion risks due primarily to international trade. Determining movement parameters for fruit flies is critical to effective surveillance and control strategies, from setting quarantine boundaries after incursions to development of agent-based models for management. While mark-release-recapture, flight mills, and visual observations have been used to study tephritid movement, none of these techniques give a full picture of fruit fly movement in nature. Tracking tagged flies offers an alternative method which has the potential to observe individual fly movements in the field, mirroring studies conducted by ecologists on larger animals. In this study, harmonic radar (HR) tags were fabricated using superelastic nitinol wire which is light (tags weighed less than 1 mg), flexible, and does not tangle. Flight tests with wild melon flies showed no obvious adverse effects of HR tag attachment. Subsequent experiments successfully tracked HR tagged flies in large field cages, a papaya field, and open parkland. Unexpectedly, a majority of tagged flies showed strong flight directional biases with these biases varying between flies, similar to what has been observed in the migratory butterflyPieris brassicae. In field cage experiments, 30 of the 36 flies observed (83%) showed directionally biased flights while similar biases were observed in roughly half the flies tracked in a papaya field. Turning angles from both cage and field experiments were non-random and indicate a strong bias toward continued “forward” movement. At least some of the observed direction bias can be explained by wind direction with a correlation observed between collective melon fly flight directions in field cage, papaya field, and open field experiments. However, individual mean flight directions coincided with the observed wind direction for only 9 out of the 25 flies in the cage experiment and half of the flies in the papaya field, suggesting wind is unlikely to be the only factor affecting flight direction. Individual flight distances (meters per flight) differed between the field cage, papaya field, and open field experiments with longer mean step-distances observed in the open field. Data on flight directionality and step-distances determined in this study might assist in the development of more effective control and better parametrize models of pest tephritid fruit fly movement.
Cutaneous expression of growth-associated protein 43 is not a compelling marker for human nerve regeneration in carpal tunnel syndrome
Authors: Carroll Liam , Sandy-Hindmarch Oliver , Baskozos Georgios , Zhu Guan Cheng , McCarthy Julia , Schmid Annina
Published: November 2022

Growth-associated protein 43 (GAP-43) has long been used as a marker for nerve regeneration following nerve injury, with numerous in vitro and animal studies showing its upregulation in regenerating neurons. In humans, expression of GAP-43 has predominantly been examined in skin biopsies from patients with peripheral neuropathies; with several studies showing a reduction in GAP-43 immunoreactive cutaneous nerve fibres. However, it remains elusive whether cutaneous GAP-43 is a valid marker for human nerve regeneration. Here, we present a cohort of 22 patients with electrodiagnostically confirmed carpal tunnel syndrome (CTS), used as a model system for focal nerve injury and neural regeneration after decompression surgery. We evaluate GAP-43 immunoreactivity and RNA expression levels in finger skin biopsies taken before and 6 months after surgery, relative to healthy controls. We further classify patients as ‘regenerators’ or ‘non-regenerators’ based on post-surgical epidermal re-innervation. We demonstrate that patients with CTS have lower GAP-43 positive intra-epidermal nerve fibre density (IENFD) before surgery than healthy controls. However, this difference disappears when normalising for total IENFD. Of note, we found surgery did not change GAP-43 expression in IENF, with no differences both in patients who were classified as regenerators and non-regenerators. We also did not identify pre-post surgical differences in cutaneous GAP-43 gene expression or associations with regeneration. These findings suggest cutaneous GAP-43 may not be a compelling marker for nerve regeneration in humans.
Technological infrastructure, sleep, and rest-activity patterns in a Kaqchikel Maya community
Authors: McKinnon Leela , Samson David R. , Nunn Charles L. , Rowlands Amanda , Salvante Katrina G. , Nepomnaschy Pablo A.
Published: November 2022

Sleep duration, quality, and rest-activity pattern—a measure for inferring circadian rhythm—are influenced by multiple factors including access to electricity. Recent findings suggest that the safety and comfort afforded by technology may improve sleep but negatively impact rest-activity stability. According to the circadian entrainment hypothesis, increased access to electric lighting should lead to weaker and less uniform circadian rhythms, measured by stability of rest-activity patterns. Here, we investigate sleep in a Maya community in Guatemala who are in a transitional stage of industrialization. We predicted that (i) sleep will be shorter and less efficient in this population than in industrial settings, and that (ii) rest-activity patterns will be weaker and less stable than in contexts with greater exposure to the natural environment and stronger and more stable than in settings more buffered by technologic infrastructure. Our results were mixed. Compared to more industrialized settings, in our study population sleep was 4.87% less efficient (78.39% vs 83.26%). We found no significant difference in sleep duration. Rest-activity patterns were more uniform and less variable than in industrial settings (interdaily stability = 0.58 vs 0.43; intradaily variability = 0.53 vs 0.60). Our results suggest that industrialization does not inherently reduce characteristics of sleep quality; instead, the safety and comfort afforded by technological development may improve sleep, and an intermediate degree of environmental exposure and technological buffering may support circadian rhythm strength and stability.
Synergistic effect between plant extracts and fluoride to protect against enamel erosion: An in vitro study
Authors: Carvalho Thiago Saads , Pham Khoa , Rios Daniela , Niemeyer Samira , Baumann Tommy
Published: November 2022

Polyphenol-rich solutions, such as plant extracts and teas, can modify the salivary pellicle and improve the protection against dental erosion. In this study, we further explored how these polyphenol-rich plant extracts solutions behave in the presence of fluoride. We distributed enamel specimens into 9 groups (n = 15): Control_No_F- (Deionized water); Control_F- (500 ppm F-), Grape_Seed_No_F- (Grape seed extract), Grape_Seed_F- (Grape seed extract + 500 ppm F-), Grapefruit_Seed_No_F- (Grapefruit seed extract), Grapefruit_Seed_F- (Grapefruit seed extract + 500 ppm F-), Blueberry_No_F- (Blueberry extract), Blueberry_F- (Blueberry extract + 500 ppm F-), and Sn2+/F-_Rinse (commercial solution containing 800 ppm Sn2+ and 500 ppm F-). The specimens were submitted to 5 cycles (1 cycle per day), and each cycle consisted of: salivary pellicle formation (human saliva, 30 min, 37°C), modification of the pellicle (2 min, 25°C), pellicle formation (60 min, 37°C), and an erosive challenge (1 min, citric acid). Between cycles, the specimens were kept in a humid chamber. Relative surface hardness (rSH), relative surface reflection intensity (rSRI) and calcium released to the acid were analysed, using general linear models, and Kruskal-Wallis with post-hoc Dunn’s tests. We observed that the presence of fluoride in synergy with the extract solutions provided better protection than the groups containing extract or fluoride only. For rSH, we observed a significant main effect of extracts (F(4,117) = 9.20; p<0.001) and fluoride (F(1,117) = 511.55; p<0.001), with a significant interaction (F(3,117) = 6.71; p<0.001). Grape_Seed_F- showed the best protection, better than fluoride, and Sn2+/F-_Rinse. Calcium results also showed greater protection for the groups containing fluoride, whereas for rSRI, despite a significant interaction between extract and fluoride (F(3,117) = 226.05; p<0.001), the differences between the groups were not as clearly observed. We conclude that polyphenols from plant extracts, when combined with fluoride, improve the protective effect of salivary pellicles against enamel erosion.
A new perspective on the evolution of “Kawara” roof tiles in Ryukyu: A multidisciplinary non-destructive analysis of roof tile transition at Shuri Castle, Ryukyu Islands, Japan
Authors: Aoyama Hiroaki , Yamagiwa Kaishi , Taira Wataru , Kon Takeshi
Published: November 2022

A unique historical architecture was created at Shuri Castle (Shuri-jo) in the Ryukyu Islands by its “Kawara” roof tiles. After the 13th and 14th centuries, Kawara tiles were introduced to the Ryukyu Islands from several regions, including China, Korea, and mainland Japan, and evolved shapes and patterns that are unique to this island region. However, the transition of some internal features, such as the chemical components and microstructure, had not been analyzed. This study used a multi-faceted approach for such internal data and non-destructive quantitative methods to propose a new perspective on the evolution of historical Ryukyuan Kawara. We analyzed two styles of Ryukyuan Kawara from the 13th to 15th centuries and found that the material processing and firing conditions of the two styles were very similar, even though it had been suggested that they had different origins. A quantitative analysis of tiles from the 16th to 19th centuries revealed a transition in color tone to red, leading to the modern traditional Ryukyuan tiles; traces of changes in firing conditions were also found along with this transition. Finally, the study revealed that the evolution of Ryukyuan Kawara consisted of changed factors, e.g. surface color, and unchanged factors, e.g. paste density. Previous archaeological studies mainly focused on changing external characteristics, such as form and pattern; however, our analysis showed that the internal features changed, while the elemental composition and paste density remained constant from the appearance of the roof tiles until the 19th century. We propose that this is related to different responses of individual factors to external stressors, such as the social context, which may be common to other archaeological artifacts as well. Our study provides a new perspective on the evolution of Ryukyuan Kawara and presents a different discussion of and methods for the chronological study of material culture.