bluuebunny/crossref_metadata_2025 huggingface dataset:
Threshold studies for a hot beam superradiant laser including an atomic guiding potential
Authors: Fasser Martin , Hotter Christoph , Plankensteiner David , Ritsch Helmut
Published: January 2024

Motivated by the outstanding short time stability and reliable continuous operation properties of microwave clock masers, intense worldwide efforts target the first implementation of their optical analogues based on narrow optical clock transitions and using laser cooled dilute atomic gases. While as a central line of research large efforts are devoted to create a suitably dense continuous ultracold and optically inverted atom beam source, recent theoretical predictions hint at an alternative implementation using a filtered thermal beam at much higher density. Corresponding numerical studies give encouraging results but the required very high densities are sensitive to beam collimation errors and inhomogeneous shifts. Here we present extensive numerical studies of threshold conditions and the predicted output power of such a superradiant laser involving realistic particle numbers and velocities along the cavity axis. Detailed studies target the threshold scaling as a function of temperature as well as the influence of eliminating the hottest part of the atomic distribution via velocity filtering and the benefits of additional atomic beam guiding. Using a cumulant expansion approach allows us to quantify the significance of atom-atom and atom-field correlations in such configurations. We predict necessary conditions to achieve a certain threshold photon number depending on the atomic temperature and density. In particular, we show that the temperature threshold can be significantly increased by using more atoms. Interestingly, a velocity filter removing very fast atoms has only almost negligible influence despite their phase perturbing properties. On the positive side an additional conservative optical guiding towards cavity mode antinodes leads to significantly lower threshold and higher average photon number. Interestingly we see that higher order atom-field and direct atom-atom quantum correlations play only a minor role in the laser dynamics, which is a bit surprising in the superradiant regime.
Towards a new PhD Curriculum for Digital Finance
Authors: Baals Lennart John , Osterrieder Jörg R. , Hadji-Misheva Branka , Liu Yiting
Published: January 2024

The rapidly evolving field of Digital Finance necessitates a new, interdisciplinary approach to doctoral training. This manuscript presents a comprehensive curriculum designed to equip early-stage researchers with the skills and knowledge required to navigate the complexities of modern finance. The curriculum is structured around four pillars: Training through Research and Mandatory Scientific Training, Advanced Scientific Training, Transferable Skills Training, and Training through Secondments. Together, these pillars provide a balanced mix of theoretical knowledge, practical experience, and soft skills. The program also emphasizes international collaboration through conferences and offers online courses for accessibility and sustainability. By addressing key challenges such as data quality, deployment of complex models, trust in AI-supported products, and labor shortages, the program aims to foster innovation and competitiveness in the European Finance industry. The curriculum's alignment with the European Digital Finance Package and integration with leading institutions ensures its relevance and potential for significant impact.
Innovative vanillin yielding from lignin: process modelling and assessment
Authors: Cabeza Sánchez Álvaro , Trygve Berglihn Olaf , Ottaviano Eloy , Rücker Theresa , Pettersen Torbjørn , Wittgens Bernd , Aliko Abraham , Gálvez Lucía , López María
Published: January 2024

In this work, we present the modelling of a novel process to promote vanillin production from lignin using PODIC®. The model includes the PODIC© production, lignin depolymerisation and final product separation. Furthermore, a complete assessment of the proposed process in terms of economic and environmental performance was performed. Regarding the economic evaluation, a comprehensive study was done leading to high investment (13.76 €/kgLignin) and operational (5.16 €/kgLignin) costs. The main reasons for the elevated costs were identified and further alternative process configuration were evaluated too. Despite this, the main result was that the proposed process is challenging to commercialize. Since it is complex to obtain profits even at larger scales, improvement of the process design to improve the economics are considered. An environmental analysis of the environmental impacts generated by the overall production process of vanillin and phenolic compounds was carried out considering energy consumption, human health, greenhouse gas emissions, water consumption and human toxicity. Electricity consumption of the PODIC® reactor was identified as the hotspot of the system. The CO2 emissions were also compared with the Borregaard process and found to be similar.
Is entrepreneurship a key factor in the development of European countries? A proposal for an innovation readiness environment (IRE) index
Authors: Fabbro Elisa , Kyrdoda Yuliia , Dore Salvatore , Marzi Giacomo , Borruso Giuseppe , Battino Silvia , Piani Giovanni Cristiano , Vianelli Donata
Published: January 2024

This study investigates the complex interplay among innovation, research and development (R&D), and entrepreneurship within the context of European nations. The focus of the study is also on the contributory role of tertiary educational institutions in nurturing entrepreneurial activities. To deepen the understanding of these multifaceted relationships and their subsequent impact on regional economies, the research introduces a novel metric termed the Innovation Readiness Environment (IRE) index. This index combines various indicators such as R&D expenditure, patenting rates, firm size, and educational levels, thereby providing a framework for evaluating the innovative capabilities and entrepreneurial success of firms in a given region. Utilization of this index offers policymakers and stakeholders a nuanced understanding of the regional innovation ecosystem, facilitating the identification of both strengths and deficiencies. This, in turn, enables the formulation of targeted policy interventions to enhance both innovation and entrepreneurship. One salient conclusion drawn from this study is the pivotal role of tertiary education in catalysing entrepreneurial ventures. The findings posit that higher levels of entrepreneurial education significantly supplement an individual's likelihood of entrepreneurial success by imparting the requisite skills and knowledge indispensable in a competitive business milieu. Higher education institutions, by fostering an environment conducive to innovation, emerge as critical agents in the cultivation of entrepreneurial acumen and the stimulation of economic expansion. The study further incorporates a spatial analytical framework to elucidate the regional specificities of innovation at the pan-European scale.
Methodology of Natsal-COVID Wave 2: A large, quasi-representative, longitudinal survey measuring the impact of COVID-19 on sexual and reproductive health in Britain
Authors: Dema Emily , Conolly Anne , Willis Malachi , Copas Andrew J. , Clifton Soazig , Blake Margaret , Riddell Julie , Bosó Pérez Raquel , Tanton Clare , Bonell Chris , Sonnenberg Pam , Mercer Catherine H. , Mitchell Kirstin R. , Field Nigel
Published: January 2024

Background The National Surveys of Sexual Attitudes and Lifestyles COVID study (Natsal-COVID) was designed to understand the impact of COVID-19 on Britain’s sexual and reproductive health (SRH). Natsal-COVID Wave 1 survey and qualitative follow-up interviews were conducted in 2020. The Wave 2 survey was designed to capture one-year prevalence estimates for key SRH outcomes and measure changes over the first year of the pandemic. We describe the Wave 2 survey methodology and assess the sample representativeness. Methods Natsal-COVID Wave 2 was conducted March-April 2021; approximately one year after the start of Britain’s first national lockdown. Data were collected using an online web-panel survey administered by Ipsos. The sample comprised a longitudinal sample of Wave 1 participants who had agreed to re-contact plus a sample of participants residing in Britain, aged 18-59, including a boost sample comprising people aged 18-29. Questions covered reproductive health, relationships, sexual behaviour and SRH service use. Quotas and weighting were used to achieve a quasi-representative sample of the British population. Comparisons were made with recent national probability surveys, Natsal-3 (2010-12) and Natsal-COVID Wave 1 to understand bias. Results A total of 6,658 individuals completed the survey. In terms of gender, age, ethnicity, and rurality, the weighted Natsal-COVID Wave 2 sample was like the general population. Participants were less likely to be married or to report being in good health than the general population. The longitudinal sample (n=2,098) were broadly like participants who only took part in Wave 1 but were older. Among the sexually active, longitudinal participants were less likely to report multiple sexual partners or a new sexual partner in the past year compared to those who only took part in Wave 1. Conclusions Natsal-COVID collected longitudinal, quasi-representative population data to enable evaluation of the population-level impact of COVID-19 on SRH and to inform policy.
The genome sequence of the Lunar Underwing, Omphaloscelis lunosa (Haworth, 1809)
Authors: Boyes Douglas , Johnson Harriet F. ,   University of Oxford and Wytham Woods Genome Acquisition Lab,   Darwin Tree of Life Barcoding collective,   Wellcome Sanger Institute Tree of Life programme,   Wellcome Sanger Institute Scientific Operations: DNA Pipelines collective,   Tree of Life Core Informatics collective,   Darwin Tree of Life Consortium
Published: January 2024

We present a genome assembly from an individual female Omphaloscelis lunosa (the Lunar Underwing; Arthropoda; Insecta; Lepidoptera; Noctuidae). The genome sequence is 661.9 megabases in span. Most of the assembly is scaffolded into 32 chromosomal pseudomolecules, including the W and Z sex chromosomes. The mitochondrial genome has also been assembled and is 15.47 kilobases in length. Gene annotation of this assembly on Ensembl identified 18,931 protein coding genes.
The genome sequence of the Chequered Fruit-tree Tortrix, Pandemis corylana (Fabricius, 1794)
Authors: Boyes Douglas , Sims Ian , Lees David C. , Eagles Marianne ,   University of Oxford and Wytham Woods Genome Acquisition Lab,   Natural History Museum Genome Acquisition Lab,   Darwin Tree of Life Barcoding collective,   Wellcome Sanger Institute Tree of Life Management, Samples and Laboratory team,   Wellcome Sanger Institute Scientific Operations: Sequencing Operations,   Wellcome Sanger Institute Tree of Life Core Informatics team,   Tree of Life Core Informatics collective,   Darwin Tree of Life Consortium
Published: January 2024

We present a genome assembly from an individual male Pandemis corylana (the Chequered Fruit-tree Tortrix; Arthropoda; Insecta; Lepidoptera; Tortricidae). The genome sequence is 441.6 megabases in span. Most of the assembly is scaffolded into 30 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 15.53 kilobases in length. Gene annotation of this assembly on Ensembl identified 19,608 protein coding genes.
The genome sequence of the Scorched Carpet, Ligdia adustata (Denis & Schiffermüller, 1775)
Authors: Boyes Douglas , Lewis Owen T. ,   University of Oxford and Wytham Woods Genome Acquisition Lab,   Darwin Tree of Life Barcoding collective,   Wellcome Sanger Institute Tree of Life Management, Samples and Laboratory team,   Wellcome Sanger Institute Scientific Operations: Sequencing Operations,   Wellcome Sanger Institute Tree of Life Core Informatics team,   Tree of Life Core Informatics collective,   Darwin Tree of Life Consortium
Published: January 2024

We present a genome assembly from an individual female Ligdia adustata (the Scorched Carpet; Arthropoda; Insecta; Lepidoptera; Geometridae). The genome sequence is 399.7 megabases in span. Most of the assembly is scaffolded into 31 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 15.43 kilobases in length. Gene annotation of this assembly on Ensembl identified 17,979 protein coding genes.
Platelet-rich plasma - a revolutionary therapeutic option in multi-disciplinary indications
Authors: Kiełkowicz Aleksandra , Pisera Piotr , Pactwa Filip , Popińska Zuzanna , Żmuda Bartłomiej , Ślusarczyk Daniel , Jakubowska Wiktoria , Żuberek Michał
Published: January 2024

Background: Platelet-rich plasma (PRP) was originally described as a small volume of plasma that contains higher concentrations of platelets, compared to peripheral blood. Although currently the use of PRP in most indications is off-label, it is not prohibited. Initially, PRP was used for wound healing and tissue regeneration in fields such as orthopaedics, dermatology, maxillofacial surgery and dentistry.

Aim of the study: The aim of this article was to present and summarise the modern production methods, the mechanism of action at the molecular and biochemical level and the most important uses and indications of PRP in present-day medicine.

Material and methods: A cross-sectional search of relevant literature was performed in databases using accepted wording. Publications from 2003-2023 were included. The entire process has been supplemented with additional procedures to increase the reliability of this publication.

Results: Orthopaedics has gained many minimally invasive therapeutic solutions thanks to PRP. Its effects on ligament and tendon tissues have been studied, where promising data have been proven. Also in aesthetic medicine and dermatology, many treatment strategies have been developed using PRP, mainly for the treatment of acne, androgenic alopecia and delaying tissue ageing as much as possible.

Conclusion: Platelet-rich plasma has found application in the treatment of many conditions in orthopaedics, dermatology, aesthetic medicine and dentistry. It is characterised by good therapeutic efficacy, with relatively low risk. However, high-quality studies are still lacking to provide more reliable data.
Protest Slogans of the Snow Revolution in Russia (2011–2012) as an Expression of Peaceful Resistance against the Authorities
Authors: Gołębiowska-Suchorska Agnieszka
Published: January 2024

The expression of resistance against the authorities during the street protests of the so-called snow revolution in the years 2011-2012 reached a level of mass creativity and visuality previously and since unrecorded in Russian social life and, despite its lack of success, it is worth attention due to its openness and intensity. During the snow revolution a certain corpus of texts (slogans) was shaped, with repeatability typical for folklore – it was a recurrence of themes, motifs, characters, linguistic tricks, images, textual models. The aim of analyzing selected protest slogans is to showcase contexts that constitute the source of oppositional expression on the textual (slogan on a poster), visual (image on a poster) and object (artifacts) level. The examples of the protest creativity presented in the article prove that verbal, visual and material ways of resistance realized functions typical for political folklore, such as integrating the rebels, mocking the stronger enemy as a defense strategy, unmasking the crimes of the government, and expressing the expectations of the protesters.
Wzorzec interpretacyjny „wiary w funkcjonowanie państwa” w opowieściach wspomnieniowych Wilamowian o Volksliście
Authors: Król Tymoteusz
Published: January 2024

Wilamowianie to grupa etniczna mieszkająca na pograniczu Śląska i Małopolski. Są oni potomkami osadników przybyłych z zachodniej Europy, o czym świadczy zachowany do dziś germański język wilamowski (Wymysiöeryś). W 1941 r. Wilamowianie podpisali Volkslistę, co było jednym z powodów ich powojennych prześladowań. W opowieściach wspomnieniowych wielu Wilamowian na ten temat pojawiają się powtarzające się elementy narracji – wzorce interpretacyjne, toposy i skamieliny językowe, które w wyniku procesu fabularyzacji i folkloryzacji są dzielone przez wszystkich członków grupy. Tę grupę nazwałem wilamowskocentryczną wspólnotą pamięci. Jednym z najważniejszych wzorców interpretacyjnych występujących w narracji tej grupy jest wzorzec „wiary w funkcjonowanie państwa”. Jego głównym zadaniem jest usprawiedliwienie Wilamowian jako grupy przed odbiorcą z zewnątrz, który – według wyobrażeń członków wspólnoty – ma fałszywy obraz tego, czym była Volkslista.
O sile wspólnego śpiewania. Żądanie zmiany
Authors: Laskowska-Otowinowska Justyna
Published: January 2024

Na przykładzie dwóch wydarzeń historycznych: śpiewającej rewolucji z 1988 r. oraz protestów przeciw sfałszowanym wyborom w Białorusi z lat 2020–2021, artykuł prezentuje sposób wykorzystania zbiorowego śpiewu do celów społeczno-politycznych. Jednym z nich jest budowanie/wzmacnianie tożsamości narodowej, drugim wyrażenie żądania zmian. Mechanizmy wykorzystywane do osiągnięcia pożądanego efektu zawarte są w tradycyjnych funkcjach pieśni.
„Byle dostatniej, byle nowocześniej”. Dylematy PRL-owskiej modernizacji i samofolkloryzacji w powieści Edwarda Redlińskiego Awans
Authors: Tarnowska Małgorzata
Published: January 2024

Celem artykułu jest rozważenie emancypacyjnego wymiaru samofolkloryzacji – kategorii zaproponowanej przez Ewę Klekot na określenie strategii odzyskiwania głosu przez podmioty podporządkowane, rozumianej jako jeden z ważnych elementów procesów nowoczesności. Materiałem do analizy procesów społeczno-kulturowych okresu powojennego przy użyciu tej kategorii jest powieść Edwarda Redlińskiego Awans (1973), przedstawiająca dylematy samofolkloryzacji mieszkańców fikcyjnej socjalistycznej wsi w kontekście powojennych procesów modernizacyjnych. Analiza tej powieści pozwala zadać pytanie, po pierwsze, o emancypacyjny wymiar samofolkloryzacji, a po drugie, o związki utworu Redlińskiego z przemianami społecznymi w Polsce Ludowej drugiej połowy XX w.
(Afro)Karaiby, czyli świat
Authors: Kuligowski Waldemar
Published: January 2024

Recenzja: Religia, historia i przyszłość w kulturze afrokaraibskiej, red. Jakub Bohuszewicz, Dariusz Brzostek, Wydawnictwo Uniwersytetu Jagiellońskiego, Kraków 2022.
A Dynamic Model for Managing Volunteer Engagement
Authors: Ata Baris , Tongarlak Mustafa H. , Lee Deishin , Field Joy
Published: January 2024

Managing Volunteer Engagement

Non-profit organizations that provide food, shelter, and other services to people in need, rely on volunteers to deliver their services. Unlike paid labor, non-profit organizations have less control over unpaid volunteers’ schedules, efforts, and reliability. However, these organizations can invest in volunteer engagement activities to strive for a steady and adequate supply of volunteer labor. The paper, “A Dynamic Model for Managing Volunteer Engagement”, models the volunteer management process. The paper derives a dynamic control policy that judiciously uses the non-profit’s resources for volunteer engagement activities depending on explicit congestion thresholds, thereby lowering the overall cost of the non-profit operation.
Mis-implementation of evidence-based behavioural health practices in primary care: lessons from randomised trials in Federally Qualified Health Centers
Authors: Dopp Alex R. , Hindmarch Grace , Chan Osilla Karen , Meredith Lisa S. , Manuel Jennifer K. , Becker Kirsten , Tarhuni Lina , Schoenbaum Michael , Komaromy Miriam , Cassells Andrea , Watkins Katherine E.
Published: January 2024

Background:

Implementing evidence-based practices (EBPs) within service systems is critical to population-level health improvements, but also challenging, especially for complex behavioural health interventions in low-resource settings. ‘Mis-implementation’ refers to poor outcomes from an EBP implementation effort; mis-implementation outcomes are an important, but largely untapped, source of information about how to improve knowledge exchange.

Aims and objectives:

We present mis-implementation cases from three pragmatic trials of behavioural health EBPs in US Federally Qualified Health Centers (FQHCs).

Methods:

We adapted the Consolidated Framework for Implementation Research and its Outcomes Addendum into a framework for mis-implementation and used it to structure the case summaries with information about the EBP and trial, mis-implementation outcomes, and associated determinants (barriers and facilitators). We compared the three cases to identify shared and unique mis-implementation factors.

Findings:

Across cases, there was limited adoption and fidelity to the interventions, which led to eventual discontinuation. Barriers contributing to mis-implementation included intervention complexity, low buy-in from overburdened providers, lack of alignment between providers and leadership, and COVID-19-related stressors. Mis-implementation occurred earlier in cases that experienced both patient- and provider-level barriers, and that were conducted during the COVID-19 pandemic.

Discussion and conclusion:

Multilevel determinants contributed to EBP mis-implementation in FQHCs, limiting the ability of these health systems to benefit from knowledge exchange. To minimise mis-implementation, knowledge exchange strategies should be designed around common, core barriers but also flexible enough to address a variety of site-specific contextual factors, and should be tailored to relevant audiences such as providers, patients, and/or leadership.
Productive interactions without impact? An empirical investigation of researchers’ struggle to improve the elderly’s oral health
Authors: Gulbrandsen Magnus , Tellmann Silje Maria
Published: January 2024

Background:

Achieving impact of research is often seen as requiring productive interaction between researchers and stakeholders. Still, interactions are sometimes not ‘productive’ and lead to no visible impacts.

Aims and objectives:

This article studies repeated attempts by researchers to involve different stakeholders to facilitate pathways to societal impact. We look in particular at possible explanations for the lack of impacts.

Methods:

This is a longitudinal case study of an interdisciplinary group of researchers where we acted as participant observers over a period of close to six years. The studied researchers have in various ways targeted the societal challenge of oral healthcare for the elderly.

Findings:

We see the societal challenge as a ‘problem area’ where researchers are one of many stakeholder groups, and where the different stakeholders vary in salience, legitimacy and power. A lack of funding for the research led to continuous efforts to involve new stakeholders, envision new forms of impact, and establish a sense of urgency of the societal challenge.

Discussion and conclusion:

The case highlights different gaps in the problem area that are organisational, social, and institutional. We also find that there are gaps in how the fundamental societal issue is described and prioritised, and in how responsibilities for finding solutions are distributed. This seems to lead researchers away from extensive interaction and towards more traditional forms of impact through randomised controlled trials and technology push initiatives.
Laser beam shaping using a photoinduced azopolymer droplet-based mask
Authors: Barille R. , Korbut A. , Zielinska S. , Ortyl E. , Perez D. G.
Published: January 2024

The dewetting of an azopolymer droplet, followed by the photostructuration of the evaporated droplet, is employed to create an amplitude mask. This straightforward process yields a large area featuring periodic micro- and nanostructures. The resulting pattern is utilized to generate a nondiffracting beam. Starting with a Gaussian beam illuminating the amplitude mask, the critical aspect is the production of a bright, ring-shaped beam with a high radius-to-width ratio and symmetric central laser spots, each with the same intensity. This alternative approach to shaping a laser beam is demonstrated as a rapid and cost-effective fabrication technique.
High harmonic generation in epitaxially grown zinc oxide films
Authors: Journigan Troie , Liu Yangyang , Cabello Christian , Berriel S. Novia , Rudawski Nicholas G. , Banerjee Parag , Chini Michael
Published: January 2024

High harmonic generation (HHG) in solids has been identified as a promising mechanism for light source generation and for spectroscopy of materials. HHG from bulk solids, however, often suffers from nonlinear propagation effects, resulting in a loss of spectral coherence and the skewing of spectroscopic measurements. Here, we study HHG in epitaxial ZnO thin films grown on Al2O3 substrates using atomic layer deposition. We find that the HHG emission consists of narrow spectral peaks, in contrast to those seen in bulk, and that the dependence of the harmonic yield on the film thickness differs for above-gap and below-gap harmonics, which can be understood from analytical models based on the linear and nonlinear response of the medium. The measured harmonic spectra depend qualitatively on the preparation of the films, with as-grown films generating even harmonic orders, which are absent in annealed films. The results are interpreted using transmission electron microscopy measurements, which indicate different morphologies for the as-grown and annealed films.
Directional silicon nano-antennas for quantum emitter control designed by evolutionary optimization
Authors: Hernandez Romain , Wiecha Peter R. , Poumirol Jean-Marie , Agez Gonzague , Arbouet Arnaud , Ressier Laurence , Paillard Vincent , Cuche Aurélien
Published: January 2024

We optimize silicon nano-antennas to enhance and direct the emission of local quantum sources. We combine global evolutionary optimization (EO) with frequency domain electrodynamical simulations and compare design strategies based on resonant and non-resonant building blocks. Specifically, we investigate the performance of models with different degrees of freedom but comparable amounts of available material. We find that simpler geometric models allow significantly faster convergence of the optimizer, which, expectedly, comes at the cost of a reduced optical performance. We finally analyze the physical mechanisms underlying the directional emission that also comes with an emission rate enhancement and find a surprising robustness against perturbations of the source emitter location. This makes the structures highly interesting for actual nano-fabrication. We believe that optimized, all-dielectric silicon nano-antennas have high potential for genuine breakthroughs in a multitude of applications in nanophotonics and quantum technologies.
Dynamics and stability conditions of a spectrally combined beam based on a diode laser array
Authors: Feng Peng , Li Danni , Peng Qinqi , Yang Chengshuang , Zhuang Yinghao , Zhang Qingsong , Wu Zhen , Zhong Zheqiang
Published: January 2024

In the spectral beam combining (SBC) system based on a diode laser array (DLA), optical feedback is required to lock the wavelengths of the diode lasers, but excessive feedback may lead to instability. To analyze the dynamics and stability conditions of the SBC system based on DLA, a model for the round-trip propagation of the feedback beam in the external cavity is established, and the optical feedback is calculated using the diffraction integral method. On this basis, a stability condition (the feedback-factor is smaller than 0.07) is introduced to assess the potential stability of the SBC system. If the feedback-factor exceeds 0.07, the combined laser can be in chaos. Based on the stability condition, we analyzed the influence of external-cavity parameters on the external-cavity feedback. The results indicate that the optical feedback becomes increasingly strong with the increasing focal length of the transform lens and the reflectivity of the output coupler, while it decreases with the increasing reflectivity of the front facet of the diode emitter. This work paves the way toward the stabilized spectral beam combining system based on a diode laser array.
Deep learning enables contrast-robust super-resolution reconstruction in structured illumination microscopy
Authors: Chen Yunbo , Liu Qingqing , Zhang Jinfeng , Ye Zitong , Ye Hanchu , Zhu Yukun , Kuang Cuifang , Chen Youhua , Liu Wenjie
Published: January 2024

Structured illumination microscopy (SIM) is a powerful technique for super-resolution (SR) image reconstruction. However, conventional SIM methods require high-contrast illumination patterns, which necessitate precision optics and highly stable light sources. To overcome these challenges, we propose a new method called contrast-robust structured illumination microscopy (CR-SIM). CR-SIM employs a deep residual neural network to enhance the quality of SIM imaging, particularly in scenarios involving low-contrast illumination stripes. The key contribution of this study is the achievement of reliable SR image reconstruction even in suboptimal illumination contrast conditions. The results of our study will benefit various scientific disciplines.
Wide-field color imaging through multimode fiber with single wavelength illumination: plug-and-play approach
Authors: Zhang Hailong , Wang Lele , Xiao Qirong , Ma Jianshe , Zhao Yi , Gong Mali
Published: January 2024

Multimode fiber (MMF) is extensively studied for its ability to transmit light modes in parallel, potentially minimizing optical fiber size in imaging. However, current research predominantly focuses on grayscale imaging, with limited attention to color studies. Existing colorization methods often involve costly white light lasers or multiple light sources, increasing optical system expenses and space. To achieve wide-field color images with typical monochromatic illumination MMF imaging system, we proposed a data-driven “colorization” approach and a neural network called SpeckleColorNet, merging U-Net and conditional GAN (cGAN) architectures, trained by a combined loss function. This approach, demonstrated on a 2-meter MMF system with single-wavelength illumination and the Peripheral Blood Cell (PBC) dataset, outperforms grayscale imaging and alternative colorization methods in readability, definition, detail, and accuracy. Our method aims to integrate MMF into clinical medicine and industrial monitoring, offering cost-effective high-fidelity color imaging. It serves as a plug-and-play replacement for conventional grayscale algorithms in MMF systems, eliminating the need for additional hardware.
WSe2/BN heterostructure as saturable absorber for a diode-pumped passively Q-switched 2 µm solid-state laser
Authors: Gao Lulu , Zhai Xuejun , Jiang Linyu , Sui Qixiao , Niu Deqing , Zhang Qingliang , Lan Ruijun , Shen Yingjie
Published: January 2024

We have successfully achieved the synthesis of heterojunction consisting of WSe2 and BN, by using a liquid phase exfoliation method, and characterization of the prepared materials under the microstructure. The WSe2/BN heterojunction was used as a saturable absorber in the Tm:YAP laser for passively Q-switched operation, and a pulsed laser with an output wavelength around 2 µm range was successfully obtained. After comparing the effects of resonators composed of different cavity mirrors, it is concluded that when the curvature radius of the input mirror is 250 mm and the transmittance of the output coupler is 2.5%, the best output performance was obtained. The maximum average output power of 834 mW was achieved, with a pulsed repetition frequency of 43.51 kHz and a minimum pulse duration of 1.28 µs, corresponding to a peak power of 14.97 W and a maximum single pulse energy of 19.17 µJ.
Efficient automated high dynamic range 3D measurement via deep reinforcement learning
Authors: Zhang Pan , Zhong Kai , Li Zhongwei , Shi Yusheng
Published: January 2024

High dynamic range 3D measurement technology, utilizing multiple exposures, is pivotal in industrial metrology. However, selecting the optimal exposure sequence to balance measurement efficiency and quality remains challenging. This study reinterprets this challenge as a Markov decision problem and presents an innovative exposure selection method rooted in deep reinforcement learning. Our approach’s foundation is the exposure image prediction network (EIPN), designed to predict images under specific exposures, thereby simulating a virtual environment. Concurrently, we establish a reward function that amalgamates considerations of exposure number, exposure time, coverage, and accuracy, providing a comprehensive task definition and precise feedback. Building upon these foundational elements, the exposure selection network (ESN) emerges as the centerpiece of our strategy, acting decisively as an agent to derive the optimal exposure sequence selection. Experiments prove that the proposed method can obtain similar coverage (0.997 vs. 1) and precision (0.0263 mm vs. 0.0230 mm) with fewer exposures (generally 4) compared to the results of 20 exposures.
Research on the tilt-to-length coupling noise suppression method inside the gravitational wave detection telescope
Authors: Fan Wen Tong , Song Jie , Hai Hong Wen , Fang Si Jun , Zhao Kai , Zhang Rui , Li Bo Hong , Luo Jian , Sun Qi Cheng , Fan Lei , Li Zi Zheng , Yeh Hsien-Chi , Yan Yong
Published: January 2024

As an integral component of the laser interferometry measurement system, the tilt-to-length (TTL) coupling noise inside the telescope stands out as a critical noise factor that requires meticulous consideration. In the TianQin project, the non-geometric TTL-coupled noise inside the telescope should be less than 0.22 pm/Hz1/2. Additionally, the wavefront aberration RMS at the small pupil of the telescope needs to be better than 0.0065 λ. These requirements set for the telescope are exceptionally stringent. To address this challenge, this study aims to relax the wavefront aberration requirements by mitigating non-geometric TTL coupling noise, while ensuring the non-geometric TTL coupling noise remains below 0.22 pm/Hz1/2. By controlling the coupling aberration proportion, the wavefront aberration RMS at the small pupil of the telescope can be relaxed to 0.014 λ. Alternatively, optimizing the Gaussian beam waist radius can relax the wavefront aberration RMS to 0.016 λ. By simultaneously utilizing two optimization methods, the wavefront aberration at the small pupil of the telescope can be reduced to 0.033 λ, resulting in an impressive success rate of 91.15% in meeting the noise requirements.
Cooperative correction method for distortion and dispersion of deflected field of view in Risley-prism bionic-human-eye imaging systems
Authors: Huang Feng , Huang Duanhao , Yang Shumin , Wang Pengfei
Published: January 2024

The Risley-prism imaging system (RPIS) is a powerful way to achieve bionic human eye imaging with great advantages on large field of view (FOV) and variable resolution imaging owing to the autonomous controlled deflection of light. But the imaging dispersion originating from nonlinear and uneven light deflection results in limited imaging wavelength that seriously hinders its application. The existing solutions for imaging dispersion mainly rely on the hardware, which generally has bulky structure and limited improvement on image. Besides, the existing image evaluation methods for dispersion are not suitable for RPIS due to inhomogeneous dispersion. Herein, this paper systematically analyzes the mechanism and characteristics of dispersion in the RPIS, and proposes a cooperative correction method for image distortion and dispersion of multiple-color imaging, achieving the elimination of distortion and dispersion simultaneously without changing the optical structure. A dispersion evaluation index based on Pearson's correlation coefficient (PCC) is also established, and the objectivity and validity of the index are proved by experiments. Furthermore, a kind of compact RPIS based on an RGB camera is built, and both indoor and outdoor experiments are conducted. The experimental results demonstrate that proposed algorithm has strong universality and robustness for various scenes and targets.
Ultra-compact electro-optic phase modulator based on a lithium niobate topological slow light waveguide
Authors: Wang Ying , Fei HongMing , Lin Han , Bai Jie , Zhang MingDa , Liu Xin , Cao BinZhao , Tian Yuan , Xiao LianTuan
Published: January 2024

Electro-optic modulators (EOMs) are essential devices of optical communications and quantum computing systems. In particular, ultra-compact EOMs are necessary for highly integrated photonic chips. Thin film lithium niobate materials are a promising platform for designing highly efficient EOMs. However, EOMs based on conventional waveguide structures are at a millimeter scale and challenging to scale down further, greatly hindering the capability of on-chip integration. Here, we design an EOM based on lithium niobate valley photonic crystal (VPC) structures for the first time. Due to the high effective refractive index introduced by the strong slow light effect, the EOM can achieve an ultra-compact size of 4 μm×14 μm with a half-wave voltage of 1.4 V. The EOM has a high transmittance of 0.87 in the 1068 nm because of the unique spin-valley locking effect in VPC structures. The design is fully compatible with current nanofabrication technology and immune to fabrication defects. Therefore, it opens a new possibility in designing lithium niobate electro-optic modulators and will find broad applications in optical communication and quantum photonic devices.
Ultrasensitive measurement of tactile force based on a PDMS-embedded microfiber Mach-Zehnder interferometer
Authors: Li Lijun , Xu Tianzong , Ma Qian , Wang Jie , Xue Mengge , Yang Fan , Lin Zheng
Published: January 2024

This study investigates the utilization of an in-fiber interferometer embedded in polydimethylsiloxane (PDMS) to develop a highly sensitive tactile sensor. The tapered mode-field mismatch structure is more conducive to stimulating strong high order modes to promote the sensitivity of the sensor. Experimental investigations are conducted to study the sensing performance of the sensor, resulting in a sensitivity of 23.636 nm/N and a detection limit of 0.746 mN. The experiments demonstrate that employing fast Fourier transform (FFT) and inverse FFT (IFFT) methods to filter weak high order modes significantly improves the repeatability of the sensor, resulting in a repeatability error of less than 1%.
High-power 100 W Kerr-lens mode-locked ring-cavity femtosecond Yb:YAG thin-disk oscillator
Authors: Liu Heyan , Xuan Hongwen , Chen Hongshan , Hao Jingjie , Wu Fan , Zhang Shenao , Wang Qing , Yan Lisong , Zhang Jinwei
Published: January 2024

High-power femtosecond pulses delivered at a high-repetition rate will aid machining throughput and improve signal-to-noise ratios for sensitive measurements. Here we demonstrate a Kerr-lens mode-locked femtosecond Yb:YAG ring-cavity thin-disk oscillator with a multi-pass scheme for the laser beam. With four passes through the thin disk, 175-fs pulses were delivered from the oscillator at an average power of 71.5 W and a repetition rate of 65.3 MHz. The corresponding intra-cavity peak power of 110 MW is ample for intra-cavity nonlinear conversion into more exotic wavelength ranges. With six passes, the average output power reached 101.3 W. To the best of our knowledge, this is the highest average output power of any mode-locked ring laser. These results confirm the viability of using multi-pass configuration on a thin-disk ring oscillator for high-throughput femtosecond applications.
Advantages of using feedback control in microwave photonic transversal filters with Kerr microcombs
Authors: Moss David
Published: January 2024

Feedback control plays a crucial role in improving system accuracy and stability for a variety of scientific and engineering applications. Here, we theoretically and experimentally investigate the implementation of feedback control in microwave photonic (MWP) transversal filter systems based on optical microcomb sources, which offer advantages in achieving highly reconfigurable processing functions without requiring changes to hardware. We propose four different feedback control methods including (1) one-stage spectral power reshaping, (2) one-stage impulse response reshaping, (3) two-stage spectral power reshaping, and (4) two-stage synergic spectral power reshaping and impulse response reshaping. We experimentally implement these feedback control methods and compare their performance. The results show that the feedback control can significantly improve not only the accuracy of comb line shaping as well as temporal signal processing and spectral filtering, but also the system’s long-term stability. Finally, we discuss the current limitations and future prospects for optimizing feedback control in microcomb-based MWP transversal filter systems implemented by both discrete components and integrated chips. Our results provide a comprehensive guide for the implementation of feedback control in microcomb-based MWP filter systems in order to improve their performance for practical applications.
Blockchain-Technologie im Supply Chain Management – Anwendungspotenziale und Kompetenzlücken
Authors: Jede Andreas , Bensberg Frank , Klein Tabea
Published: January 2024

Unternehmen und anwendungsorientierte Forschung weisen der Blockchain-Technologie enorme Potenziale in diversen Sektoren zu. Besonders erfolgversprechend erscheint dabei der Einsatz von Blockchain-Technologien im Kontext des Supply Chain-Managements, da hiermit die Effizienz, die Transparenz und das Vertrauen zwischen den unterschiedlichen Akteuren über die gesamte Lieferkette gesteigert werden können. Ein Erfolgsfaktor für die Einführung und den Betrieb produktiver Blockchain-Lösungen bildet dabei ein adäquates Kompetenzmanagement, mit dem sichergestellt wird, dass die Mitarbeiter die notwendigen Fähigkeiten und Kenntnisse besitzen. Bestehende Kompetenzrahmen umfassen zwar eine Vielzahl digitaler Kompetenzen, jedoch adressieren diese bislang keine dedizierten Kompetenzen zum Einsatz von Blockchain-Technologien. Dieses Defizit wird mit dem vorliegenden Beitrag aufgegriffen, indem aufbauend auf einer kurzen Einführung und Darstellung der Blockchain-Technologie deren Anwendungspotenziale im Supply Chain-Management identifiziert werden. Anschließend wird ein Kompetenzrahmen zum Blockchain-basierten Supply Chain-Management entwickelt. Schließlich werden Kompetenzlücken in der Praxis aufgezeigt, Handlungsempfehlungen für Unternehmen formuliert sowie eine Schlussbetrachtung durchgeführt.
Finding the right power balance: Better study design and collaboration can reduce dependence on statistical power
Authors: Nakagawa Shinichi , Lagisz Malgorzata , Yang Yefeng , Drobniak Szymon M.
Published: January 2024

Power analysis currently dominates sample size determination for experiments, particularly in grant and ethics applications. Yet, this focus could paradoxically result in suboptimal study design because publication biases towards studies with the largest effects can lead to the overestimation of effect sizes. In this Essay, we propose a paradigm shift towards better study designs that focus less on statistical power. We also advocate for (pre)registration and obligatory reporting of all results (regardless of statistical significance), better facilitation of team science and multi-institutional collaboration that incorporates heterogenization, and the use of prospective and living meta-analyses to generate generalizable results. Such changes could make science more effective and, potentially, more equitable, helping to cultivate better collaborations.
Wanting to be part of change but feeling overworked and disempowered: Researchers’ perceptions of climate action in UK universities
Authors: Latter Briony , Demski Christina , Capstick Stuart
Published: January 2024

Interest in the relationship between the activities of universities and action on climate change is growing, but until recently there has been little focus on the critical role of researchers, particularly with regards to how research practices and culture can enable or inhibit change. This study addresses this gap, exploring researchers’ perceptions of universities’ measures to tackle their own emissions, their own engagement on issues surrounding the climate crisis, and challenges and opportunities for researchers to contribute to them. We present findings from a representative survey of 1,853 researchers from 127 UK universities across disciplines and career stages, including comparing responses across these professional differences, and analysis based on over 5,000 open text responses provided by the survey participants. The results show that while most have some knowledge of actions being taken by their universities and feel that universities’ public declarations of a climate emergency are making a difference, almost half think not enough is being done. They feel that responsibility for university climate action sits across government, universities and research councils, but almost all researchers are also personally worried about climate change and want to do more themselves to address it. For the most part, they also strongly support climate advocacy by those engaged in research. Yet high workload, uncertainty about what actions to take, perceived lack of agency or power, inflexible university processes and pressure to travel are just some of the many barriers researchers face in taking action. The study highlights how these barriers can be overcome, and the steps universities and researchers can take to better incorporate climate action into their research culture and practices.
The epidemiology of HIV infection among female sex workers in Nairobi, Kenya: A structural determinants and life-course perspective
Authors: Beattie Tara S. , Adhiambo Wendy , Kabuti Rhoda , Beksinska Alicja , Ngurukiri Pauline , Babu Hellen , Kung’u Mary , Nyamweya Chrispo , Mahero Anne ,   Maisha Fiti Study -Champions, Irungu Erastus , Muthoga Peter , Seeley Janet , Kimani Joshua , Weiss Helen A. , Kaul Rupert
Published: January 2024

High HIV prevalence among female sex workers (FSWs) is heavily influenced by structural determinants (e.g. criminalisation of sex work; violence) and significant life events (e.g. orphanhood, teenage pregnancy). This study aims to understand the epidemiology of HIV among FSWs in Nairobi, Kenya using a structural determinants and life-course perspective. Baseline cross-sectional survey data were collected June–December 2019 for the Maisha Fiti study with 1003 FSWs (aged 18–45 years). Odds ratios and 95% confidence intervals were estimated using multivariable logistic regression with a hierarchical modelling approach. HIV prevalence was 28.0%, and increased with age (<25 years 5.7%, 25–34 years 19.0%, ≥35 years 40.6%). In adjusted analyses, HIV seroprevalence was associated with childhood and adolescence including violence from militia or soldiers (AOR = 1.60; 95%CI:1.00–2.53), young age at sexual debut (≤15 years old vs. ≥18 years AOR = 0.57; 95%CI:0.39–0.84) and teenage pregnancy (AOR = 1.37; 95%CI:1.00–1.88). For adulthood the factors included lower SES score (lowest vs. highest tertile AOR = 0.63; 95%CI:0.40–0.98); reduced housing insecurity (AOR = 0.52; 95%CI:0.54–0.79); lower alcohol/drug use score (AOR = 0.44; 95%CI:0.31–0.61); and a longer duration of selling sex (0–5 years vs. ≥11 years AOR = 2.35; 95%CI:1.44–3.82). Among HIV-negative FSWs, prevalence of HIV risk factors was high (recent hunger 32.3%; internalised 67.7% and experienced 66.0% sex work stigma; recent police arrest 30.1%; recent physical or sexual violence 65.6%, condomless last sex intimate partner 71.1%; harmful alcohol or substance use 49.1%). Only 24.6% of HIV-negative FSWs reported taking PrEP. Taken together, adverse events in childhood and adolescence were associated with increased odds of living with HIV, and were more strongly associated with HIV serostatus than adulthood structural or behavioural risk factors. HIV-negative FSWs remain at high risk of HIV acquisition. This study highlights the importance of addressing adverse events throughout the life course to reduce HIV risk, and the need to continue multi-level HIV prevention and treatment efforts.