bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasma and Urine Free Glycosaminoglycans as Monitoring and Predictive Biomarkers in Metastatic Renal Cell Carcinoma: A Prospective Cohort Study
Authors: Gatto Francesco , Bratulic Sinisa , Jonasch Eric , Limeta Angelo , Maccari Francesca , Galeotti Fabio , Volpi Nicola , Lundstam Sven , Nielsen Jens , Stierner Ulrika
Published: February 2023

PURPOSE

No liquid biomarkers are approved in metastatic renal cell carcinoma (mRCC) despite the need to predict and monitor response noninvasively to tailor treatment choices. Urine and plasma free glycosaminoglycan profiles (GAGomes) are promising metabolic biomarkers in mRCC. The objective of this study was to explore if GAGomes could predict and monitor response in mRCC.

PATIENTS AND METHODS

We enrolled a single-center prospective cohort of patients with mRCC elected for first-line therapy (ClinicalTrials.gov identifier: NCT02732665 ) plus three retrospective cohorts (ClinicalTrials.gov identifiers: NCT00715442 and NCT00126594 ) for external validation. Response was dichotomized as progressive disease (PD) versus non-PD every 8‐12 weeks. GAGomes were measured at treatment start, after 6-8 weeks, and every third month in a blinded laboratory. We correlated GAGomes with response and developed scores to classify PD versus non-PD, which were used to predict response at treatment start or after 6-8 weeks.

RESULTS

Fifty patients with mRCC were prospectively included, and all received tyrosine kinase inhibitors (TKIs). PD correlated with alterations in 40% of GAGome features. We developed plasma, urine, and combined glycosaminoglycan progression scores that monitored PD at each response evaluation visit with the area under the receiving operating characteristic curve (AUC) of 0.93, 0.97, and 0.98, respectively. For internal validation, the scores predicted PD at treatment start with the AUC of 0.66, 0.68, and 0.74 and after 6-8 weeks with the AUC of 0.76, 0.66, and 0.75. For external validation, 70 patients with mRCC were retrospectively included and all received TKI-containing regimens. The plasma score predicted PD at treatment start with the AUC of 0.90 and at 6-8 weeks with the AUC of 0.89. The pooled sensitivity and specificity were 58% and 79% at treatment start. Limitations include the exploratory study design.

CONCLUSION

GAGomes changed in association with mRCC response to TKIs and may provide biologic insights into mRCC mechanisms of response.
Interaction of chiral solitons in a Bose-Einstein Condensate under density-dependent gauge potential
Authors: Gao Rui , Qiao Xin , Ma Yun-E , Jian Yue , Zhang Ai-Xia , Xue Ju-Kui
Published: February 2023

The collision between two chiral solitons in a Bose-Einstein Condensate (BEC) under density-dependent gauge potential is studied. By means of Poincaré-Lighthill-Kuo (PLK) perturbation method, the different kinds of colliding chiral soliton pairs self-consistently excited upon the background of the system are obtained analytically. The coupling of the current nonlinearity induced by the gauge potential and mean-field atomic interaction results in rich collision dynamics of chiral soliton pairs. When the atomic interaction is repulsive, head-on collisions of dark-dark and dark-bright solitons are observed. However, when the atomic interaction is attractive, unidirectional chiral dark soliton pairs are excited, and overtaking collision between two chiral dark solitons takes place. The phase shifts following the collision of soliton pairs are derived analytically and confirmed numerically. Interestingly, due to the contribution of the density-dependent gauge potential, the phase shifts of the two interacting chiral solitons are different from each other. This is distinct from the case without the density-dependent gauge potential, where the phase shifts of the two colliding ordinary solitons are the same. Thus, phase shifts of interacting chiral soliton pairs can be used to identify the chiral properties of solitons in BEC under density-dependent gauge potential. Furthermore, both elastic and inelastic collisions of chiral solitons in the system are presented numerically. The phase diagram for occurrence of elastic and inelastic collisions of chiral soliton is obtained, which strongly depends on the strength of density-dependent gauge potential.
Abortion Reform in Colombia: From Total Prohibition to Decriminalization up to Week Twenty-Four
Authors: González-Vélez Ana Cristina , Jaramillo-Sierra Isabel Cristina
Published: February 2023

On February 21, 2022, the Colombian Constitutional Court decriminalized abortion up to the twenty-fourth week of gestation and clarified that the grounds under which abortion had been allowed since 2006 should continue to apply in the remaining weeks of pregnancy. This decision, more than any other, is the material manifestation of the strategic efforts of a broad sector of Colombian feminism grouped under the slogan Causa Justa (Just Cause). This article briefly presents the history of feminist mobilization around abortion in Colombia, emphasizing its contributions for thinking about progressive reform in highly conservative environments: the importance of taking advantage of political opportunities, the appropriation of legal reform, and incremental change. Three different moments are discussed: political mobilization and the construction of meaning (1979–2004), progressive legal mobilization and appropriation of incremental reform (2004–2018), and feminist legal mobilization (2018–present).
The Influence of Early-Life Health Conditions on Life Course Health
Authors: Flores Manuel , Wolfe Barbara L.
Published: February 2023

We expand on previous studies investigating the links between early health and later health by examining four distinct dimensions of early-life health and multiple life course outcomes, including the age of onset of serious cardiovascular diseases (CVDs) and several job-related health outcomes. The four dimensions of childhood health are mental, physical, self-reported general health, and severe headaches or migraines. The data set we use includes men and women in 21 countries from the Survey of Health, Ageing and Retirement in Europe. We find that the different dimensions of childhood health have unique ties to later outcomes. For men, early mental health problems play a stronger role for life course job-related health outcomes, but early poor/fair general health is more strongly linked to the spike in onset of CVDs in their late 40s. For women, these links between childhood health dimensions and life course outcomes are similar but are less clear-cut than for men. The spike in onset of CVDs in women's late 40s is driven by those with severe headaches or migraines, while those with early poor/fair general health or mental health problems do worse as captured by job-related outcomes. We also delve into and control for possible mediating factors. Exploring the links between several dimensions of childhood health and multiple health-related life course outcomes will enable a better understanding of how health inequalities originate and are shaped over the course of people's lives.
Later, Fewer, None? Recent Trends in Cohort Fertility in South Korea
Authors: Hwang Jisoo
Published: February 2023

South Korea and other developed regions in East Asia have become forerunners of prolonged lowest-low fertility. South Korea's total fertility rate has been below 1.3 for two decades, the longest duration among OECD countries. Using vital statistics and census data, I study recent trends in the country's cohort fertility covering women born before the 1960s to those born in the 1980s. Analyzing outcomes at both the intensive margin of fertility (i.e., timing and number of children) and the extensive margin of family formation (i.e., marriage and childlessness), I document three novel patterns. First, the driver of low fertility has evolved across birth cohorts, from married women having later and fewer childbirths, to fewer women getting married, and finally to fewer women having children even if married. Second, a decomposition analysis of marriage and fertility changes indicates that the marriage and fertility decline was driven by changes within educational groups rather than by changes in women's educational composition. Third, the relationship between women's educational attainment and marriage or fertility was negative for the 1960s cohort, but an inverted U-shaped education gradient emerged beginning with the 1970s cohort.
Disappearing Rooms
Authors: Castañeda Michelle
Published: February 2023

In Disappearing Rooms Michelle Castañeda lays bare the criminalization of race enacted every day in US immigration courts and detention centers. She uses a performance studies perspective to show how the theatrical concept of mise-en-scène offers new insights about immigration law and the absurdist dynamics of carceral space. Castañeda draws upon her experiences in immigration trials as an interpreter and courtroom companion to analyze the scenography—lighting, staging, framing, gesture, speech, and choreography—of specific rooms within the immigration enforcement system. Castañeda’s ethnographies of proceedings in a “removal” office in New York City, a detention center courtroom in Texas, and an asylum office in the Northeast reveal the depersonalizing violence enacted in immigration law through its embodied, ritualistic, and affective components. She shows how the creative practices of detained and disappeared people living under acute duress imagine the abolition of detention and borders. Featuring original illustrations by artist-journalist Molly Crabapple, Disappearing Rooms shines a light into otherwise hidden spaces of law within the contemporary deportation regime.

Duke University of Press Scholars of Color First Book Award Recipient
Antimicrobial peptides do not directly contribute to aging in Drosophila, but improve lifespan by preventing dysbiosis
Authors: Hanson Mark A. , Lemaitre Bruno
Published: February 2023

Antimicrobial peptides (AMPs) are innate immune effectors first studied for their role in host defence. Recent studies have implicated these peptides in the clearance of aberrant cells and in neurodegenerative syndromes. In Drosophila, many AMPs are produced downstream of Toll and Imd NF-κB pathways upon infection. Upon aging, AMPs are upregulated, drawing attention to these molecules as possible causes of age-associated inflammatory diseases. However, functional studies overexpressing or silencing these genes have been inconclusive. Using an isogenic set of AMP gene deletions, we investigated the net impact of AMPs on aging. Overall, we found no major effect of individual AMPs on lifespan, with the possible exception of Defensin. However, ΔAMP14 flies lacking seven AMP gene families displayed reduced lifespan. Increased bacterial load in the food of aged ΔAMP14 flies suggested that their lifespan reduction was due to microbiome dysbiosis, consistent with a previous study. Moreover, germ-free conditions extended the lifespan of ΔAMP14 flies. Overall, our results did not point to an overt role of individual AMPs in lifespan. Instead, we found that AMPs collectively impact lifespan by preventing dysbiosis during aging.
Termination of the Chirality Confusion of Peribysins
Authors: Kanehara Ryuhi , Tanaka Kazuaki , Yamada Takeshi , Koshino Hiroyuki , Hashimoto Masaru
Published: February 2023

Peribysins belong to a family of eremophilanes isolated from marine Periconia byssoides OUPS-N133 and terrestrial P. macrospinosa KT3863. Their absolute configurations were determined to be the (4S)-enantiomers based on the modified Mosher’s method, chemical derivatizations, density functional theory (DFT)-based electronic circular dichroism (ECD) spectral analysis, and DFT-based [α]D calculations. Danishefsky’s and Reddy’s total syntheses assigned the (4R)-forms for the marine peribysins despite agreeing with the (4S)-configuration for the terrestrial peribysin Q (5). This paper reports the successful solution of this chirality confusion of peribysins by reproducing the ECD spectrum of peribysin G bis(p-bromobenzoate) prepared from peribysin A (1) isolated from terrestrial P. byssoides TS60. 2β-Hydroxyperibysin A (6), which was isolated by changing the culture conditions of the above fungus, was converted to (4S)-peribysin E MTPA esters. These compounds showed identical 1H NMR spectral properties to those reported in the isolation paper.
Understanding the Ownership Structure of Corporate Bonds
Authors: Koijen Ralph S.J. , Yogo Motohiro
Published: February 2023

Insurers are the largest institutional investors of corporate bonds. However, a standard theory of insurance markets, in which insurers maximize firm value subject to regulatory or risk constraints, predicts no allocation to corporate bonds. We resolve this puzzle in an equilibrium asset pricing model with leverage-constrained households and institutional investors. Insurers have relatively cheap access to leverage through their underwriting activity. They hold a leveraged portfolio of low-beta assets in equilibrium, relaxing other investors’ leverage constraints. The model explains recent empirical findings on insurers’ portfolio choice and its impact on asset prices. (JEL G11, G12, G22, G23)
Therapeutically applied Minecraft groups with neurodivergent youth
Authors: Kilmer Elizabeth , Spangler Johnny , Kilmer Jared
Published: February 2023

Background: Therapeutically applied Minecraft groups are an intervention designed to support social engagement and growth in youth. The flexible interaction format and use of a popular digital game support the fit of this intervention for use with neurodivergent youth. Minecraft is leveraged to support opportunities to build authentic relationships and social confidence in an engaging, low-stakes environment with peers. The group format allows for real-world social practice with peers, while the game environment can create motivation to interact with others, and provides multiple modes for such interaction (i.e., chat, building/movement with the avatar).

Methods: This article outlines the theoretical foundations of therapeutically applied Minecraft groups as well as practical considerations for implementation. The method outlined includes the justification for this method, process of creating support groups, check-in and check-out processes, and in-game activity examples for different situations.

Results: Use cases are included to illustrate how the methods have been used in the past to support social growth with neurodivergent youth. Use cases include examples of different Minecraft servers, such as the habitat, and identifying stresses of social growth such as school anxiety and how the use of therapeutically applied Minecraft helped.

Conclusions: Therapeutically applied Minecraft can provide opportunities for peer connection and social practice in a facilitated environment. Though the use of Minecraft and other games to support learning and social connection is prevalent in the media, the academic research in this area is sparse. This article provides general guidelines for therapeutically applied Minecraft groups as well as calls for more formal research in this area.
The impact of COVID-19 severity on pregnancy outcomes among Iraqi women: a retrospective observational study
Authors: Sami Salih Othman , Khalid Abdulridha Manal
Published: February 2023

Background: COVID-19-infected pregnant women may be asymptomatic or symptomatic. Symptomatic tend to have a severe infection and could be at increased risk of complications such as preterm birth, NICU, and stillbirth. This study aimed to identify the most common signs and symptoms and assess the pre-existing risk of COVID-19 infection during pregnancy:  length of hospital stay, premature labor, and complications according to the severity of COVID-19 illness.

Methods: This retrospective study was conducted in the obstetric and gynecological wards of 359 pregnant women. After reviewing medical records, patient and disease data were collected.

Results: Most patients were asymptomatic and mild. The most common signs and symptoms were fever, cough, and dyspnea. COVID-19 infected pregnant with a medical history of hypertension, or diabetes had more severe COVID-19 infection. COVID-19-infected pregnant women with severe illness or aged ≥ 40 years had a prolonged hospital stay. Severe COVID-19 disease was significantly associated with preterm birth, stillbirth, and the need for a neonatal intensive care unit.

Conclusion: Severe COVID-19 infection in pregnancy is linked to pregnancy and birth complications, mainly among pregnant women with a positive medical history.
Why cost-effectiveness thresholds for global health donors differ from thresholds for Ministries of Health (and why it matters)
Authors: Drake Tom , Chi Y-Ling , Morton Alec , Pitt Catherine
Published: February 2023

Healthcare cost-effectiveness analysis is increasingly used to inform priority-setting in low- and middle-income countries and by global health donors. As part of such analyses, cost-effectiveness thresholds are commonly used to determine what is, or is not, cost-effective. Recent years have seen a shift in best practice from a rule-of-thumb 1x or 3x per capita GDP threshold towards using thresholds that, in theory, reflect the opportunity cost of new investments within a given country. In this paper, we observe that international donors face both different resource constraints and opportunity costs compared to national decision makers. Hence, their perspective on cost-effectiveness thresholds must be different. We discuss the potential implications of distinguishing between national and donor thresholds and outline broad options for how to approach setting a donor-perspective threshold. Further work is needed to clarify healthcare cost-effectiveness threshold theory in the context of international aid and to develop practical policy frameworks for implementation.
Temporal distribution and clinical characteristics of the Alpha, Delta and Omicron SARS-CoV-2 variants of concern in Laikipia, Kenya: institutional and community-based genomic surveillance
Authors: W. Lambisia Arnold , H. Mudhune Godfrey , M. Morobe John , Said Mohammed Khadija , O. Makori Timothy , Ndwiga Leonard , W. Mburu Maureen , O. Moraa Edidah , Musyoki Jeniffer , Murunga Nickson , N. Waliaula Isaac , K. Mumelo Arthur , Bejon Philip , Isabella Ochola-Oyier Lynette , Githinji George , Nokes James , Agoti Charles
Published: February 2023

Background: Understanding the molecular epidemiology and clinical presentation of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOC) in rural-urban populations in Kenya is important for informing future public health responses and clinical care.

Methods: We undertook a retrospective analysis of the clinical presentation and phylogenetic relatedness of specimens from 97 SARS-CoV-2 cases collected between 24th April and 31st December 2021 in Laikipia county, Kenya. VOC were related to observed symptoms. Phylogenetic analyses included contemporaneous sequences from across Kenya and the globe, to contextualise local transmission dynamics.

Results: These sequences fell into three VOC; Alpha (n=8), Delta (n=52) and Omicron (n=37). We estimated 75 independent SARS-CoV-2 introductions into the county. The Alpha and Delta VOC were commonly detected in persons aged 31 to 45 years, 50.0% and 30.8%, respectively. The Omicron VOC was mostly detected in 16 to 30-year-olds (51.4%). Whereas relative to the other VOCs, Omicron was associated with mild upper-respiratory tract symptoms (cough, OR 3.78; 95% CI 1.1 – 16.74, p= 0.026) and sore throat, OR 22.42; 95% CI 7.11 – 81.40, p<0.001), Delta was associated with moderate to severe lower-respiratory tract symptoms (shortness of breath, OR 26.8; 95% CI 3.89 – 1158.14, p<0.001) and fever (OR 6.11; 95% CI 1.57 – 35.35, p= 0.004). Post-acute phase neurological complications were suspected in four Delta infected cases (neuralgia, neuritis, peripheral neuropathy, numbness of hand and tinnitus).

Conclusion: We highlight the distinctive clinical characteristics of SARS-CoV-2 VOCs, as observed in Laikipia, Kenya, to support evidence-based clinical decisions. Multiple introductions of the VOCs were recorded despite the public health measures that were in place questioning their effectiveness during the study period.
The Development Features of the Monoprofiled Towns with the Chemistry Speciality
Authors: Lomovcev D. , Vinichenko A. , Kizimov M.
Published: February 2023

The professional education specifics of the chemical industry based on the Tula region experience are considered in the article. The long-term management experience of the cooperation between the agencies of the secondary professional education and the chemical enterprises is investigated. The authors explore the implementation of the federal project «Proffessionalitet» and the actual initiative practice of the employers in the professional education management.
The New Stakeholder Theory on Organizational Purpose
Authors: McGahan Anita M.
Published: February 2023

The new stakeholder theory (NST) grapples with two canonical questions: Which stakeholders are enfranchised in organizations? How is the value created through stakeholder collaboration distributed and experienced by stakeholders? This paper first describes how the NST builds on original stakeholder theory to ask these two specific questions. The defining features of the NST are (i) a broad range of dependent variables, (ii) descriptiveness, (iii) formalized analysis, (iv) boundaries on stakeholder enfranchisement, and (v) analytic links to other established theories. The paper then assesses the assumptions and implications of this theory for understanding organizational purpose. A primary idea is that the NST conceptualizes purpose as originating in the goals, needs, and interests of stakeholders as complex, nuanced actors. Under the NST, the organization is conceived of as a tool—a functionalized construction—through which enfranchised stakeholders pursue a shared purpose that leads to experiences of stakeholder value in terms that are defined by the relevant stakeholders themselves. The survival and profitability of an organization depends on its effectiveness and efficiency as a tool for accomplishing mutual stakeholder aims, which are what define organizational purpose.

History: This paper has been accepted for the Strategy Science Special Issue on Corporate Purpose.

Funding: Funded by Social Sciences and Research Council of Canada.
CIRCULARIDADES GEOGRÁFICAS: ESPAÇO, ESCALA E TEMPO
Authors: Lopes Jahan Natanael Domingos
Published: February 2023

Com o intuito de se compreenderem o Espaço e o Tempo, entremete-se circularidade a partir da Escala. Vertem-se, pela ontologia, em fenômenos da experiencialidade em uma una-tríade do espaço-escala-tempo. Desse modo, tem-se a espacialidade através da análise temporal e a temporalidade através da síntese espacial. Circula-se, pois, a pensar do local ao Global (em unificação) e, também, do lugar ao Mundo (em fragmentação) conforme o processo de dissociação-associada. Conjunto a se embrenhar na perspectiva geográfica, têm-se as correlações: o Espaço geográfico (totalidade) e o meio (unidade) e, também, o Tempo geográfico (totalidade) e o momento (unidade). Convoca-se, do meio, a abertura temporal entre o início e o fim, ademais, os três momentos, na escalaridade diferencial de conceituação, aludem a uma ontologia própria. Da escalaridade espaço-tempo há, da escala grande: início, meio e fim; outrossim, da pequena: fim, meio e início. Ambas em prospecção lógico-ontológicas e, inclusive, axiológicas em vista de constituição da criação e da produção do espaço-escala-tempo. Desse modo, concebeu-se através da ontologia uma prospecção das categorias – Espaço, Escala e Tempo – em conceitos que se convertem de modo sintético-analítico.
Guilty of hiding a data breach
Authors: Jones Nigel
Published: February 2023

What does the criminal conviction of Uber's former CISO mean for the information security sector? The case highlights the need for CISOs to ensure that they have a clear line to the board, and a robust plan for how to deal with security incidents ahead of time.
Preparing for crisis: are you ready to be attacked?
Authors: Kenny Luke
Published: February 2023

How can you tell if your organisation is really prepared for a cyber attack? Focusing too heavily on technological solutions can result in key aspects being overlooked – including the necessary skills and awareness among your staff and whether you have the right processes in place, and the people ready and prepared to use them, in case of an attack.
The experience of working informal carers of older people: a qualitative diary study
Authors: Lam Winnie Wing Yee , Nielsen Karina , Kelly Ciara M.
Published: February 2023

This article expands understanding of the experiences of working carers by analysing their care activities and applying cognitive appraisal theory to explore how different resources affect carers’ appraisal processes. A total of 18 carers from the UK and Hong Kong took part in a qualitative daily diary study. The contributions of the article include providing a broader conceptualisation of care activities and considering the implications of cognitive appraisals and resources in the experience of combining work and care. The findings provide insights into future research design and support development.
Theoretical and computational study of the effects of the complex chirality parameter in chiral-coated planar waveguides
Authors: Enriquez Jim A. , Torres Pedro
Published: February 2023

A theoretical and computational study of the effects of the real and imaginary parts of the complex chirality parameter on the characteristics of light propagation in planar waveguides is presented. Symmetric and asymmetric structures using complex chiral media in the cladding region are analyzed. The guided modes are hybrid modes due to coupling between electric and magnetic fields in the chiral medium. Changes in the chirality parameter in magnitude and handedness produce changes in the dispersion curves and electromagnetic fields of the guided modes. The characteristics of the guided modes are evidenced in simulations of the transmission and absorption spectra of the structures. The results obtained indicate that the light propagation characteristics of these structures could be used to design and fabricate novel photonic devices.
Nonlocality and quantum correlations in Ince–Gauss structured light modes
Authors: González-Domínguez María A. , Piceno-Martínez A. Elena , Rosales-Zárate Laura E. C.
Published: February 2023

Structured light has many applications in areas such as quantum information and quantum optics. The angular momentum of structured light makes it possible to access higher dimensional systems. Ince–Gaussian beams are the solution of the paraxial wave equation in elliptical coordinates, which are characterized by a parameter called ellipticity. In this work, we obtain expressions for the Wigner function and Bell inequality for Ince–Gauss modes. This is done through the corresponding generalization of the structured light modes that the Ince–Gauss modes represent and therefore of the Wigner function. Geometric representations of structured light modes are of great use here. The Wigner function is important for the purpose of determining the nonlocal properties of Ince–Gauss modes. In this way, we demonstrate the nonlocality of the Ince–Gauss modes through the violation of the Bell inequality. We also give a detailed analysis of the behavior of the Bell function and the violation of the Bell inequality of Laguerre–Gauss modes relevant for our description of Ince–Gauss modes, therefore characterizing their nonlocality.
Discrete Talbot effect in modulated lattices with PT symmetric perturbations
Authors: Kang Xinyue , Wang Hao , Dou Lichao , Chen Qixuan , Zhang Qian , Zhao Tingjun , Zhan Kaiyun
Published: February 2023

We demonstrate both theoretically and numerically that the periodic self-imaging phenomenon of light patterns with certain input periods can be effectively realized in a three-layered optical lattice with parity–time symmetric modulations, which can introduce a modulation phase to the lattice structure. By varying the ratio of coupling coefficients, the Talbot distance can be engineered, which can be further tuned by adjusting the modulation phase. The Talbot effect occurs only if the modulation phase belongs to a specific set: {±π/3,±π/2,±2π/3,±π}.
Influence of thermal effects in microresonators on the locking range in self-injection locking of laser diodes
Authors: Shi Wenqi , Zou Canwen , Cao Yulian , Liu Jianguo
Published: February 2023

Stable narrow-linewidth lasers generated by self-injection locking systems have revolutionized applications from optical frequency metrology to astronomy. However, the dynamics for the self-injection locking system are intrinsically intertwined with thermal effects, which can generate a nonnegligible resonance drift in the microresonator and result in large detuning from the required regime. In this paper, we introduce the thermal effect, depending on the photon number, into self-injection locking systems with Rayleigh backscattering. We obtain a set of time-domain rate equations to describe the dynamics of laser-diode–cavity–microresonator systems and derive analytical formulas for effective detuning. The analytical results match well with our numerical simulations, and the effective detuning locking position moves forward as the value of the thermal effect coefficient decreases. We also analyze the dependence of the locking range and stable range on thermal effects, and our calculations show that, based on our approach, the stable range can be optimized effectively and the locking range is extended. Our results have the potential to optimize laser diode frequency stabilization experiments.
How to suppress radiative losses in high-contrast integrated Bragg gratings
Authors: Hammer Manfred , Farheen Henna , Förstner Jens
Published: February 2023

High-contrast slab waveguide Bragg gratings with 1D periodicity are investigated. For specific oblique excitation by semi-guided waves at sufficiently high angles of incidence, the idealized structures do not exhibit any radiative losses, such that reflectance and transmittance for the single port mode add strictly up to one. We consider a series of symmetric, fully and partly etched finite gratings, for parameters found in integrated silicon photonics. These can act as spectral filters with a reasonably flattop response. Apodization can lead to more box shaped reflectance and transmittance spectra. Together with a narrowband Fabry–Perot filter, these configurations are characterized by reflection bands, or transmittance peaks, with widths that span three orders of magnitude.
Recognition and localization of asymmetric spectra in FBG sensing networks
Authors: Hu Jinhua , Di Kangjian , Ren Danping , Deng Yujing , Zhao Jijun
Published: February 2023

We propose a deep learning demodulation method based on a long short-term memory (LSTM) neural network for fiber Bragg grating (FBG) sensing networks. Interestingly, we find that both low demodulation error and distorted spectrum recognition are realized using the proposed LSTM-based method. Compared with conventional demodulation methods, including Gaussian-fitting, convolutional neural network, and the gated recurrent unit, the proposed method improves the demodulation accuracy being close to 1 pm and achieves a demodulation time of 0.1s for 128-FBG sensors. Furthermore, our approach can realize 100% accuracy of distorted spectra recognition and complete the location of spectra with spectrally encoded FBG sensors.
Real-time demonstration of a low-complexity PS scheme for 16QAM-DMT signals in an IM-DD system
Authors: Zhang Long , Wang Kaihui , Wang Chen , Chen Ming , Ding Junjie , Sang Bohan , Shi Junting , Liu Jiaxuan , Wang Mingxv , Wei Yi , Chen Yun , Zhao Li , Zhou Wen , Yu Jianjun
Published: February 2023

We experimentally demonstrated a low-complexity probabilistic shaping (PS) 16-ary quadrature amplitude modulation (16QAM) scheme based on intra-symbol bit-weighted distribution matching (Intra-SBWDM) for discrete multi-tone (DMT) symbols with field-programmable gate array implementation in an intensity modulation and direct detection (IM-DD) system. Different from the traditional PS scheme such as Gallager many-to-one mapping, hierarchical distribution matching and constant composition distribution matching, the Intra-SBWDM scheme with lower computation and hardware complexity does not need to continuously refine the interval to find the target symbol probability, nor does it need a look-up table, so it does not introduce a large number of extra redundant bits. In our experiment, four PS parameter values (k = 4, 5, 6, and 7) are investigated in a real-time short-reach IM-DD system. 31.87-Gbit/s net bit PS-16QAM-DMT (k = 4) signal transmission is achieved. The results show that the receiver sensitivity in terms of the received optical power of the real-time PS scheme based on Intra-SBWDM (k = 4) over OBTB/20 km standard single-mode fiber can be improved by about 1.8/2.2 dB at the bit error rate (BER) of 3.8 × 10−3, compared to the uniformly-distributed DMT. In addition, the BER is steadily lower than 3.8 × 10−3 during a one-hour measurement for PS-DMT transmission system.
Experimental investigation of BDFA-based O-band direct-detection transmission using an optical recirculating loop
Authors: Hong Yang , Taengnoi Natsupa , Bottrill Kyle R. H. , Wang Yu , Sahu Jayanta K. , Petropoulos Periklis , Richardson David J.
Published: February 2023

We implemented a bismuth-doped fiber amplifier (BDFA) based optical recirculating loop to investigate the performance of amplified O-band transmission over appreciable distances. Both single-wavelength and wavelength-division multiplexed (WDM) transmission were studied, with a variety of direct-detection modulation formats. We report on (a) transmission over lengths of up to 550 km in a single-channel 50-Gb/s system operating at wavelengths ranging from 1325 nm to 1350 nm, and (b) rate-reach products up to 57.6 Tb/s-km (after accounting for the forward error correction redundancy) in a 3-channel system.
Chaotic mode-competition dynamics in a multimode semiconductor laser with optical feedback and injection
Authors: Iwami Ryugo , Kanno Kazutaka , Uchida Atsushi
Published: February 2023

Photonic computing has attracted increasing interest for the acceleration of information processing in machine learning applications. The mode-competition dynamics of multimode semiconductor lasers are useful for solving the multi-armed bandit problem in reinforcement learning for computing applications. In this study, we numerically evaluate the chaotic mode-competition dynamics in a multimode semiconductor laser with optical feedback and injection. We observe the chaotic mode-competition dynamics among the longitudinal modes and control them by injecting an external optical signal into one of the longitudinal modes. We define the dominant mode as the mode with the maximum intensity; the dominant mode ratio for the injected mode increases as the optical injection strength increases. We deduce that the characteristics of the dominant mode ratio in terms of the optical injection strength are different among the modes owing to the different optical feedback phases. We propose a control technique for the characteristics of the dominant mode ratio by precisely tuning the initial optical frequency detuning between the optical injection signal and injected mode. We also evaluate the relationship between the region of the large dominant mode ratios and the injection locking range. The region with the large dominant mode ratios does not correspond to the injection-locking range. The control technique of chaotic mode-competition dynamics in multimode lasers is promising for applications in reinforcement learning and reservoir computing in photonic artificial intelligence.
Simulated depolarization ratios for dust and smoke at laser wavelengths: implications for lidar application
Authors: Huang Zhongwei , Shen Xingtai , Tang Shihan , Zhou Tian , Dong Qingqing , Zhang Shuang , Li Meishi , Wang Yongkai
Published: February 2023

Polarization measurements have been widely used to detect aerosol properties by remote sensing in recent decades. To better understand the polarization characteristics of aerosols by lidar, the numerically exact T-matrix method was used to simulate the depolarization ratio (DR) of dust and smoke aerosols at typical laser wavelengths in this study. The results show that the DRs of dust and smoke aerosols have obviously different spectral dependences. Moreover, the ratio of DRs at two wavelengths has an obvious linear relationship with the microphysical properties of aerosols, including aspect ratio, effective radius and complex refractive index. At short wavelengths, we can use it to invert the absorption characteristics of particles, further improving the detection ability of lidar. Comparing the simulation results of different channels, DR, (color ratio) CR and (lidar ratio) LR have a good logarithmic fitting relationship at 532 nm and 1064 nm, which helps to classify the aerosol types. On this basis, a new inversion algorithm, “1β+1α+2δ”, was presented. By this algorithm, the backscattering coefficient (β), extinction coefficient (α), DR (δ) at 532 nm and 1064 nm can be used to expand the range of inversion and compare lidar data with different configurations to obtain more extensive optical characteristics of aerosols. Our study enhances the application of laser remote sensing in aerosol observations more accurately.
Time-dependent Mandel Q parameter analysis for a hexagonal boron nitride single photon source
Authors: Jones Callum , Xavier Jolly , Vartabi Kashanian Samir , Nguyen Minh , Aharonovich Igor , Vollmer Frank
Published: February 2023

The time-dependent Mandel Q parameter, Q(T), provides a measure of photon number variance for a light source as a function of integration time. Here, we use Q(T) to characterise single photon emission from a quantum emitter in hexagonal boron nitride (hBN). Under pulsed excitation a negative Q parameter was measured, indicating photon antibunching at an integration time of 100 ns. For larger integration times Q is positive and the photon statistics become super-Poissonian, and we show by comparison with a Monte Carlo simulation for a three-level emitter that this is consistent with the effect of a metastable shelving state. Looking towards technological applications for hBN single photon sources, we propose that Q(T) provides valuable information on the intensity stability of single photon emission. This is useful in addition to the commonly used g(2)(τ) function for the complete characterisation of a hBN emitter.
Excitation of multiple Fano resonances on all-dielectric nanoparticle arrays
Authors: Wang Dandan , Fan Xinye , Fang Wenjing , Niu Huijuan , Tao Jifang , Li Chuanchuan , Wei Xin , Sun Qinghe , Chen Huawei , Zhao Hening , Yin Yingxin , Zhang Wenjing , Bai Chenglin , Kumar Santosh
Published: February 2023

In this paper, an all-dielectric metasurface consisting of a unit cell containing a nanocube array and organized periodically on a silicon dioxide substrate is designed and analyzed. By introducing asymmetric parameters that can excite the quasi-bound states in the continuum, three Fano resonances with high Q-factor and high modulation depth may be produced in the near-infrared range. Three Fano resonance peaks are excited by magnetic dipole and toroidal dipole, respectively, in conjunction with the distributive features of electromagnetism. The simulation results indicate that the discussed structure can be utilized as a refractive index sensor with a sensitivity of around 434 nm/RIU, a maximum Q factor of 3327, and a modulation depth equal to 100%. The proposed structure has been designed and experimentally investigated, and its maximum sensitivity is 227 nm/RIU. At the same time, the modulation depth of the resonance peak at λ = 1185.81 nm is nearly 100% when the polarization angle of the incident light is 0 °. Therefore, the suggested metasurface has applications in optical switches, nonlinear optics, and biological sensors.
Deep-learning based broadband reflection reduction metasurface
Authors: Xie Haiyan , Yue Xiuli , Wen Kaihuai , Liang Difei , Han Tiancheng , Deng Longjiang
Published: February 2023

Reflection reduction metasurface (RRM) has been drawing much attention due to its potential application in stealth technology. However, the traditional RRM is designed mainly based on trial-and-error approaches, which is time-consuming and leads to inefficiency. Here, we report the design of a broadband RRM based on deep-learning methodology. On one hand, we construct a forward prediction network that can forecast the polarization conversion ratio (PCR) of the metasurface in a millisecond, demonstrating a higher efficiency than traditional simulation tools. On the other hand, we construct an inverse network to immediately derive the structure parameters once a target PCR spectrum is given. Thus, an intelligent design methodology of broadband polarization converters has been established. When the polarization conversion units are arranged in chessboard layout with 0/1 form, a broadband RRM is achieved. The experimental results show that the relative bandwidth reaches 116% (reflection<-10 dB) and 107.4% (reflection<-15 dB), which demonstrates a great advantage in bandwidth compared with the previous designs.
Long-wave-infrared pulse production at 11 µm via difference-frequency generation driven by femtosecond mid-infrared all-fluoride fiber laser
Authors: Cui Yifan , Huang Hao , Bai Yu , Du Weizhi , Chen Mingshu , Zhou Bohan , Jovanovic Igor , Galvanauskas Almantas
Published: February 2023

We present an ultrafast long-wave infrared (LWIR) source driven by a mid-infrared fluoride fiber laser. It is based on a mode-locked Er:ZBLAN fiber oscillator and a nonlinear amplifier operating at 48 MHz. The amplified soliton pulses at ∼2.9 µm are shifted to ∼4 µm via the soliton self-frequency shifting process in an InF3 fiber. LWIR pulses with an average power of 1.25-mW centered at 11 µm with a spectral bandwidth of ∼1.3 µm are produced through difference-frequency generation (DFG) of the amplified soliton and its frequency-shifted replica in a ZnGeP2 crystal. Soliton-effect fluoride fiber sources operating in the mid-infrared for driving DFG conversion to LWIR enable higher pulse energies than with near-infrared sources, while maintaining relative simplicity and compactness, relevant for spectroscopy and other applications in LWIR.
Enhancing and flattening multiplexed quantum entanglement by utilizing perfect vortex modes
Authors: Hu Qiwu , Wang Xutong , Zhang Rui , Ren Yuan , Liu Shengshuai , Jing Jietai
Published: February 2023

We experimentally demonstrate a method for enhancing and flattening multiplexed entanglement in the four-wave mixing (FWM) process, which is implemented by replacing Laguerre–Gaussian (LG) modes with perfect vortex (PV) modes. For the topological charge l ranging from −5 to 5, the entanglement degrees of orbital angular momentum (OAM) multiplexed entanglement with PV modes are all larger than those of OAM multiplexed entanglement with LG modes. More importantly, for OAM multiplexed entanglement with PV modes, the degree of entanglement almost does not change with the topology value. In other words, we experimentally flatten the OAM multiplexed entanglement, which cannot be achieved in OAM multiplexed entanglement with LG modes based on the FWM process. In addition, we experimentally measure the entanglement with coherent superposition OAM modes. Our scheme provides a new, to the best of our knowledge, platform to construct an OAM multiplexed system and may find potential applications in realizing the parallel quantum information protocols.
Microsphere-assisted dark-field microscopy based on a fully immersed low refractive index microsphere
Authors: Wang Jianguo , Jiang Rui , Yang Songlin , Cao Yurong , Ye Yong-Hong
Published: February 2023

Here we find that a fully immersed low refractive index SiO2 microsphere (or a microcylinder, a yeast cell) can clearly distinguish a sample with sub-diffraction features in dark-field illumination mode. The resolvable area of the sample by microsphere-assisted microscopy (MAM) is composed of two regions. One region locates below the microsphere, and a virtual image of this part of the sample is formed by the microsphere first and then the virtual image is received by the microscope. The other region is around the edge of the microsphere, and this part of the sample is directly imaged by the microscope. The simulated region of the enhanced electric field on the sample surface formed by the microsphere is consistent with the resolvable region in the experiment. Our studies show that the enhanced electric field on the sample surface generated by the fully immersed microsphere plays an important role in dark-field MAM imaging, and this finding will have a positive effect on exploring novel mechanisms in resolution improvement of MAM.
Topological edge states in photonic decorated trimer lattices
Authors: Yan Wenchao , Cheng Weizhao , Liu Weijie , Chen Feng
Published: February 2023

In recent years, topological insulators have been extensively studied in one-dimensional periodic systems, such as Su–Schrieffer–Heeger and trimer lattices. The remarkable feature of these one-dimensional models is that they support topological edge states, which are protected by lattice symmetry. To further study the role of lattice symmetry in one-dimensional topological insulators, here we design a modified version of the conventional trimer lattices, i.e., decorated trimer lattices. Using the femtosecond laser writing technique, we experimentally establish a series of one-dimensional photonic decorated trimer lattices with and without inversion symmetry, thereby directly observing three kinds of topological edge state. Interestingly, we demonstrate that the additional vertical intracell coupling strength in our model can change the energy band spectrum, thereby generating unconventional topological edge states with a longer localization length in another boundary. This work offers novel insight into topological insulators in one-dimensional photonic lattices.
Polarization-Based Idler Elimination: Enhancing
the Efficiency of Optical Parametric Amplification
Authors: Jansonas Gaudenis , Budriunas Rimantas , Valiulis Gintaras , Varanavicius Arunas
Published: February 2023

This study presents a novel way to increase the energy conversion efficiency of optical parametric amplification by eliminating the idler wave from the interaction using consecutive type-I and type-II amplification processes. By using the aforementioned straightforward approach the wavelength tunable narrow-bandwidth amplification with exceptionally high 40% peak pump-to-signal conversion efficiency and 68% peak pump depletion was achieved in the short-pulse regime, while preserving the beam quality factor of less than 1.4. The same optical layout can also serve as an enhanced idler amplification scheme.
Modeling the progression of Type 2 diabetes with underlying obesity
Authors: Yang Boya , Li Jiaxu , Haller Michael J. , Schatz Desmond A. , Rong Libin
Published: February 2023

Environmentally induced or epigenetic-related beta-cell dysfunction and insulin resistance play a critical role in the progression to diabetes. We developed a mathematical modeling framework capable of studying the progression to diabetes incorporating various diabetogenic factors. Considering the heightened risk of beta-cell defects induced by obesity, we focused on the obesity-diabetes model to further investigate the influence of obesity on beta-cell function and glucose regulation. The model characterizes individualized glucose and insulin dynamics over the span of a lifetime. We then fit the model to the longitudinal data of the Pima Indian population, which captures both the fluctuations and long-term trends of glucose levels. As predicted, controlling or eradicating the obesity-related factor can alleviate, postpone, or even reverse diabetes. Furthermore, our results reveal that distinct abnormalities of beta-cell function and levels of insulin resistance among individuals contribute to different risks of diabetes. This study may encourage precise interventions to prevent diabetes and facilitate individualized patient treatment.