bluuebunny/crossref_metadata_2025 huggingface dataset:
Perceptions of Afghan EFL undergraduate learners towards autonomous learning
Authors: Tareen Hashmatullah , Zhang BaoHui , Haand Mohammad Tahir
Published: February 2024

Autonomous learning is extensively acknowledged as a desirable goal in undergraduate education as it is found to comply with learner-centered approaches and enable learners to pursue life-long learning. However, very few empirical researchers have closely examined the actual practices of autonomous learning in the Afghan context. Therefore, the main purpose of the current research project was to investigate EFL undergraduates’ perceptions of autonomous learning, strategies used for improving language proficiency, and the extent to of these strategies are deployed. With regard to achieving these objectives, a mixed-method approach was adopted. The quantitative data were analyzed through SPSS v24 by conducting descriptive and inferential statistics. The findings revealed that EFL learners had positive perspectives on autonomous learning and were ready to take the initiative in autonomous learning. Qualitative analysis of nine EFL students’ interviews revealed that they have to create learning goals for their learning, assess themselves for controlling their learning, and take part in inside and outside classroom activities to improve their language proficiency. This case study concludes that the findings cannot be generalized to other contexts, and the study makes an original contribution to understanding the promotion of autonomous learning at Kandahar University. In addition, this study offers practical implications for policymakers and lecturers who are interested in adopting autonomous learning as a worthwhile educational goal.
Cancer Screening Services: What Do Indigenous Communities Want? A Systematic Review
Authors: Han Eunjong (Franklin) , Srinivasa Sanket , Gurney Jason , Koea Jonathan
Published: February 2024

PURPOSE

Indigenous communities experience worse cancer outcomes compared with the general population partly because of lower cancer screening access. One-size-fits-all screening programs are unsuitable for reaching Indigenous communities. In this review, we summarize available evidence on the perspectives of these communities; with a view to informing the improvement of cancer screening services to achieve equitable access.

METHODS

We undertook a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, using the databases MEDLINE, Scopus, PubMed, and Google Scholar. The search terms used were “Indigenous community or Indigenous communities,” “cancer screening,” and “facilitators, enablers, desires, or needs.” Qualitative studies published up to the August 30, 2022 investigating the perspectives of Indigenous communities on factors encouraging screening participation were included in the study. The included studies were reviewed and analyzed inductively by two independent reviewers, and key themes regarding indigenous access to cancer screening were then extracted.

RESULTS

A total of 204 unique articles were identified from the search. The title and abstracts of these studies were screened, and 164 were excluded on the basis of the exclusion and inclusion criteria. The full texts of the remaining 40 studies were examined and 18 were included in the review. Four key themes were identified pertaining to culturally tailored education and information dissemination, community involvement, positive relationships with health care providers, and individual empowerment and autonomy.

CONCLUSION

Improvements, on the basis of the key themes identified from this review, must be made at all levels of the health care system to achieve equitable screening participation in Indigenous communities. However, we recommend an investigation into the perspectives of the local Indigenous communities before the initiation of cancer screening programs.
Doxorubicin Exposure and Breast Cancer Risk in Survivors of Adolescent and Adult Hodgkin Lymphoma
Authors: Neppelenbroek Suzanne I.M. , Geurts Yvonne M. , Aleman Berthe M.P. , Lugtenburg Pieternella J. , Rademakers Saskia E. , de Weijer Roel J. , Schippers Maaike G.A. , Ta Bastiaan D.P. , Plattel Wouter J. , Zijlstra Josée M. , van der Maazen Richard W.M. , Nijziel Marten R. , Ong Francisca , Schimmel Erik C. , Posthuma Eduardus F.M. , Kersten Marie José , Böhmer Lara H. , Muller Karin , Koene Harry R. , te Boome Liane C.J. , Bilgin Yavuz M. , de Jongh Eva , Janus Cécile P.M. , van Leeuwen Flora E. , Schaapveld Michael
Published: February 2024

PURPOSE

Female Hodgkin lymphoma (HL) survivors treated with chest radiotherapy (RT) at a young age have a strongly increased risk of breast cancer (BC). Studies in childhood cancer survivors have shown that doxorubicin exposure may also increase BC risk. Although doxorubicin is the cornerstone of HL chemotherapy, the association between doxorubicin and BC risk has not been examined in HL survivors treated at adult ages.

METHODS

We assessed BC risk in a cohort of 1,964 female 5-year HL survivors, treated at age 15-50 years in 20 Dutch hospitals between 1975 and 2008. We calculated standardized incidence ratios, absolute excess risks, and cumulative incidences. Doxorubicin exposure was analyzed using multivariable Cox regression analyses.

RESULTS

After a median follow-up of 21.6 years (IQR, 15.8-27.1 years), 252 women had developed invasive BC or ductal carcinoma in situ. The 30-year cumulative incidence was 20.8% (95% CI, 18.2 to 23.4). Survivors treated with a cumulative doxorubicin dose of >200 mg/m2 had a 1.5-fold increased BC risk (95% CI, 1.08 to 2.1), compared with survivors not treated with doxorubicin. BC risk increased 1.18-fold (95% CI, 1.05 to 1.32) per additional 100 mg/m2 doxorubicin ( Ptrend = .004). The risk increase associated with doxorubicin (yes v no) was not modified by age at first treatment (hazard ratio [HR]age <21 years, 1.5 [95% CI, 0.9 to 2.6]; HRage ≥21 years, 1.3 [95% CI, 0.9 to 1.9) or chest RT (HRwithout mantle/axillary field RT, 1.9 [95% CI, 1.06 to 3.3]; HRwith mantle/axillary field RT, 1.2 [95% CI, 0.8 to 1.8]).

CONCLUSION

This study shows that treatment with doxorubicin is associated with increased BC risk in both adolescent and adult HL survivors. Our results have implications for BC surveillance guidelines for HL survivors and treatment strategies for patients with newly diagnosed HL.
The Xicaque before Spanish Rule in Leán y Mulia, Honduras
Authors: Rivera Roberto E.
Published: February 2024

In the late seventeenth century the Spanish colonial administration began to issue decrees that sought to implement the familiar colonial policies of entrada, reducción, and misión within an unconquered region of the Province of Honduras called by the Spanish Leán y Mulia. After a few short-lived settlements in the early part of the eighteenth century, a new wave of Franciscans began attempts to convert the Xicaque of Leán y Mulia in 1747–54. In 1751 the onset of a smallpox epidemic at the Franciscan misiones became the watershed event that defined subsequent interaction between the Spanish and the Xicaque and, because of this, defined Spanish policy within the region of Leán y Mulia. A fear of contracting the disease would subsequently linger in the memory of the Xicaque at the misiones and in Leán y Mulia. This dread of disease and sickness predetermined subsequent social relationships between the Xicaque and the Spanish settlers who sought their indoctrination and acculturation in subsequent decades of the eighteenth and nineteenth century with no success.
Transforming Outcomes of Spine Surgery—Exploring the Power of Enhanced Recovery After Surgery Protocol: A Systematic Review and Meta-Analyses of 15 198 Patients
Authors: Magableh Hamzah M. , Ibrahim Sufyan , Pennington Zachary , Nathani Karim Rizwan , Johnson Sarah E. , Katsos Konstantinos , Freedman Brett A. , Bydon Mohamad
Published: February 2024

BACKGROUND AND OBJECTIVES:

Enhanced recovery after surgery (ERAS) protocols aim to optimize patient outcomes by reducing the surgical stress response, expediting recovery, and reducing care costs. We aimed to evaluate the impact of implementing ERAS protocols on the perioperative surgical outcomes and financial implications associated with spine surgeries.

METHODS:

A systematic review and meta-analysis of peer-reviewed studies directly comparing outcome differences between spine surgeries performed with and without utilization of ERAS pathways was conducted along Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS:

Of 676 unique articles identified, 59 with 15 198 aggregate patients (7748 ERAS; 7450 non-ERAS) were included. ERAS-treated patients had shorter operative times (mean difference [MD]: 10.2 mins; P < .01), shorter hospitalizations (MD: 1.41 days, P < .01), fewer perioperative complications (relative risk [RR] = 0.64, P < .01), lower postoperative opioid use (MD of morphine equivalent dose: 164.36 mg; P < .01), and more rapid mobilization/time to first out-of-bed ambulation (MD: 0.92 days; P < .01). Spine surgeries employing ERAS were also associated with lower total costs (MD: $1140.26/patient; P < .01), especially in the United States (MD: $2869.11/patient, P < .01) and lower postoperative visual analog pain scores (MD = 0.56, P < .01), without any change in odds of 30-day readmission (RR: 0.80, P = .13) or reoperation (RR: 0.88, P = .60). Subanalyses based on the region of spine showed significantly lower length of stay in both cervical and lumbar surgeries implementing ERAS. Type of procedure showed a significantly lesser time-to-initiate mobilization in fusion surgeries using ERAS protocols compared with decompression.

CONCLUSION:

The present meta-analysis indicates that current literature supports ERAS implementation as a means of reducing care costs and safely accelerating hospital discharge for patients undergoing spine surgery.
100-lecie „Czasopisma Geograficznego”
Authors: Jackowski Antoni , Krzemień Kazimierz
Published: February 2024

Artykuł stanowi pierwszą próbę w miarę kompleksowego nakreślenia dziejów i rangi jednego z najważniejszych polskich periodyków z zakresu geografii – „Czasopisma Geograficznego”. Jako tekst przeglądowy artykuł ten prezentuje złożoną historię „Czasopisma”, ze szczególnym uwzględnieniem początkowych okresów jego funkcjonowania. Przedstawiono w nim wszystkie blaski i cienie obserwowane w działalności pisma, podkreślono brutalny wpływ decyzji politycznych na chwilowy upadek znaczenia periodyku w latach 50. XX w. Zwrócono uwagę na aktywność kolejnych redaktorów, wybitnych geografów, którym udało się przywrócić „Czasopismu” należne mu miejsce w geografii polskiej i światowej. Treści tego opracowania autorzy zaprezentowali na Kongresie Geografii Polskiej w Poznaniu 1 czerwca 2023 r.
„Czasopismo Geograficzne” w latach 1946–2023 – od powojennej odbudowy tożsamości po współczesne wyzwania rynku wydawnictw naukowych
Authors: Migoń Piotr , Mądry Cezary
Published: February 2024

Celem artykułu jest przybliżenie historii i przemian, jakie zachodziły w „Czasopiśmie Geograficznym” w okresie powojennym i współczesnym. Przedstawiono zarówno zmiany zachodzące w redakcji, jak i tematyce podejmowanej w artykułach i notatkach. Wyróżniono etapy: wrocławski, warszawski i poznański, co wiązało się z mobilnością siedziby redakcji. Pracę oparto na analizie zawartości „Czasopisma Geograficznego” oraz doświadczeniach autorów płynących z pełnienia funkcji redaktorów naczelnych. W części współczesnej wykorzystano analizę SWOT do zobrazowania stanu i bieżących wyzwań. Wskazano istotny wpływ zmieniającej się oceny punktowej czasopism naukowych i czynników finansowych na funkcjonowanie periodyku.
The Impact of Unemployment on Wages and Profits
Authors: Basovskaya Elena , Basovskiy Leonid
Published: February 2024

This work is devoted to an attempt to study the nature of the impact of unemployment on the level of wages and profits of enterprises. Based on Rosstat data on the unemployment rate, the average monthly nominal accrued wages of employees of organizations and the profitability of assets of industrial enterprises in the regions of the country, correlations of unemployment identified and linear regression models of these connections built. It been established that with a high level of unemployment, an increase in unemployment contributes to a decrease in wages; this influence is very small. At a low level of unemployment, starting from a level of less than 7–8%, the impact of unemployment on the level of wages begins to grow as the unemployment rate decreases until it reaches a value of 42–45% of the level of explanation of wages by the level of unemployment. This level of explanation observed at an unemployment rate of no more than 3–3.5%. If the unemployment rate does not exceed 3–3.5%, the degree of influence of unemployment on wages stabilizes and the decrease in unemployment determines the increase in wages by no more than 42–45%. Thus, the ideas about the wage curve and the Phillips curve are very simplified and do not reflect the complex nature of the influence of the unemployment level on wages. With a high level of unemployment, the growth of unemployment contributes to a decrease in the profitability of assets and, consequently, the profits of industrial enterprises. With an unemployment rate of no more than 4%, an increase in unemployment contributes to an increase in the profitability of assets and, consequently, the profits of industrial enterprises. Consequently, the idea that rising unemployment causes declining profits is overly simplistic and partly erroneous.
Features of the Formation of the Structure of the Personnel Management System
Authors: Bykova M. , Savina Irina , Shishkin Andrey
Published: February 2024

This article is devoted to the analysis of relevant and important processes in the organization’s personnel management system. Various methods of labor potential research are described. The effectiveness of these methods in the conditions of the functioning of the organization is shown. The approaches used in the process of evaluating labor collectives are considered. The classification of the structure of the professional qualification type of the labor collective is presented. The criteria for the effectiveness of labor potential are determined, depending on the nature of the activity and the operating conditions of the organization.
Polyhedral Relaxations for Optimal Pump Scheduling of Potable Water Distribution Networks
Authors: Tasseff Byron , Bent Russell , Coffrin Carleton , Barrows Clayton , Sigler Devon , Stickel Jonathan , Zamzam Ahmed S. , Liu Yang , Van Hentenryck Pascal
Published: February 2024

The classic pump scheduling or optimal water flow (OWF) problem for water distribution networks (WDNs) minimizes the cost of power consumption for a given WDN over a fixed time horizon. In its exact form, the OWF is a computationally challenging mixed-integer nonlinear program (MINLP). It is complicated by nonlinear equality constraints that model network physics, discrete variables that model operational controls, and intertemporal constraints that model changes to storage devices. To address the computational challenges of the OWF, this paper develops tight polyhedral relaxations of the original MINLP, derives novel valid inequalities (or cuts) using duality theory, and implements novel optimization-based bound tightening and cut generation procedures. The efficacy of each new method is rigorously evaluated by measuring empirical improvements in OWF primal and dual bounds over 45 literature instances. The evaluation suggests that our relaxation improvements, model strengthening techniques, and a thoughtfully selected polyhedral relaxation partitioning scheme can substantially improve OWF primal and dual bounds, especially when compared with similar relaxation-based techniques that do not leverage these new methods.

History: Accepted by David Alderson, Area Editor for Network Optimization: Algorithms & Applications.

Funding: This work was supported by the U.S. Department of Energy (DOE) Advanced Grid Modeling project, Coordinated Planning and Operation of Water and Power Infrastructures for Increased Resilience and Reliability. Incorporation of the PolyhedralRelaxations Julia package was supported by Los Alamos National Laboratory’s Directed Research and Development program under the project Fast, Linear Programming-Based Algorithms with Solution Quality Guarantees for Nonlinear Optimal Control Problems [Grant 20220006ER]. All work at Los Alamos National Laboratory was conducted under the auspices of the National Nuclear Security Administration of the U.S. DOE, Contract No. 89233218CNA000001. This work was also authored in part by the National Renewable Energy Laboratory, operated by the Alliance for Sustainable Energy, LLC, for the U.S. DOE, Contract No. DE-AC36-08GO28308.

Supplemental Material: The software that supports the findings of this study is available within the paper and its Supplemental Information ( https://pubsonline.informs.org/doi/suppl/10.1287/ijoc.2022.0233 ) as well as from the IJOC GitHub software repository ( https://github.com/INFORMSJoC/2022.0233 ). The complete IJOC Software and Data Repository is available at https://informsjoc.github.io/ .
An evaluation of a service expansion to include patients with heart failure with preserved ejection fraction
Authors: Peplow Jessica , Rees Sharon
Published: February 2024

Background/Aims

The Central London Community Healthcare Trust West Hertfordshire heart failure service expanded in 2020 to include patients with heart failure with preserved ejection fraction, in addition to the patients with heart failure with reduced ejection fraction. The patient population was predicted to double, requiring staff and service adjustments; this warranted an evaluation to determine if care targets were maintained. This study aimed to evaluate the impact of service expansion on service referral rates, length of stay in the service and clinical workload.

Methods

A retrospective quantitative evaluation of the service data from October 2020 to April 2021 was undertaken to compare referral rates, length of stay in the service and key workload metrics between patients with heart failure with reduced ejection fraction and those with heart failure with preserved ejection fraction. All referrals to the service with a new diagnosis of heart failure (confirmed by echocardiogram or magnetic resonance imaging) were considered for evaluation. Of 250 eligible referrals, 81 were selected for inclusion using a random sampling method. Data were analysed using Chi square test, Fisher’s exact test or the Wilcoxon signed rank test; a P value of <0.05 indicated statistical significance.

Results

The participants with heart failure with preserved ejection fraction had a median length of stay in the service of 17 weeks. The participants with heart failure with reduced ejection fraction had a significantly longer stay of 35.57 weeks (P<0.001) compared to a pre-expansion length of stay of approximately 17 weeks. Workload was proportional between the two cohorts. Patients with heart failure with preserved ejection fraction were more likely to be reviewed in multidisciplinary teams or by the consultant community clinic. This group was less likely to attend clinic, with 96.4% of face-to-face reviews taking place at home. Telephone reviews occurred at a similar frequency for both cohorts, comprising 50% of follow ups. The heart failure with reduced ejection fraction cohort required more alterations in medication and medication titration, generating additional follow ups.

Conclusions

The service expansion to include patients with heart failure with preserved ejection fraction has had a significant impact on workload, leading to a reduction in the quality of care for those with heart failure with reduced ejection fraction.
ECG of the month
Authors: Bloe Charles
Published: February 2024

In this issue’s ECG of the month, Charles Bloe presents the case of a 32-year-old man with a significant medical and family history who was experiencing severe central chest pain.
‘Against the state that kills women’: using photo elicitation to explore grassroots feminist discourses on gendered violence in Albania and Kosovo
Authors: Pali Brunilda , Malaj Diana
Published: February 2024

Feminists disagree about how best to understand and respond to gendered violence. Disagreements can be due, among other things, to the diversity of feminist perspectives and modes of organisation, different socioeconomic and political contexts, and different conceptions of the state and community. In this article, we explore grassroots feminist discourses on gendered violence in Albania and Kosovo. The two countries have been heavily impacted by gendered violence, but they are also home to a significant grassroots feminist mobilisation. Starting from images and imagination that have characterised this mobilisation, by using the photo-elicitation method, we interview feminist activists and academics about the ways in which they understand and interpret gendered violence, and the strategies and interventions they deem most relevant in addressing it. We offer a contextualised critique of feminist discourses and responses to gendered violence, while highlighting the contradictions and tensions that exist in such discourses and practices.
Robert Scheu's 'Englische Reise' (1898)
Authors: Carr Gilbert
Published: February 2024

Abstract: 'Englische Reise' is the unpublished travel journal of the Viennese writer and campaigner Robert Scheu (1873–1964), who in the summer of 1898 visited his uncle, the exiled socialist leader Andreas Scheu, in London. This neglected biographical source is reviewed here as a document of the appeal England once had for continental Europeans, which offers scope for comparisons with the self-image and othering of Brexit Britain. At one remove from the personal frustrations of Vienna, Scheu gains a panoptic vision of the Empire and the powers beyond. Observations on the metropolis, its public life and lieux de mémoire , are shown as exemplifying the overlaps between the journal and literary travel narrative. It lacks the latter's linearity, yet ranges over themes of concern to travel writing studies: (a) the predilection for stereotypes; (b) antitourism; (c) the picturesque landscape; (d) empire. The journal functions as a literary workshop and channel of self-reflection, where retrospect contradicts his upbeat account of his English experience. 'Englische Reise' heißt das unveröffentlichte Reisejournal des Wiener Schriftstellers und Aktivisten Robert Scheu (1873–1964), der im Sommer 1898 seinen Onkel, den in London exilierten Sozialistenführer Andreas Scheu, besuchte. Diese vernachlässigte biographische Quelle wird hier als Dokument der damaligen kontinental-europäischen Faszination für England reflektiert, was Raum für Vergleiche mit dem Selbst- und Fremdbild Großbritanniens in der Brexit-Ära eröffnet. Den persönlichen Ärgernissen des Wiener Lebens entronnen, hat Robert Scheu von London aus einen panoptischen Ausblick auf das Empire und die Weltmächte. Seine Beobachtungen über die Weltstadt, ihr öffentliches Leben und ihre lieux de mémoire werden als Beispiele für die Überschneidungen zwischen Tagebuch und literarischer Reiseerzählung kommentiert. Das Journal hat keine streng lineare Struktur, berührt jedoch Schwerpunkte, die in der Reiseliteraturforschung aktuell sind: (a) die Vorliebe für Stereotypenbildung, (b) den Antitourismus, (c) die malerische Landschaft, (d) den Imperialismus. Das Tagebuch funktioniert zugleich als literarische Werkstatt und als Medium der Selbstreflektion, die seine optimistische Darstellung des 'England'-Erlebnisses rückblickend Lügen straft.
Toward Epistemological Development Across the Curriculum: The Effect of Embedded Epistemic Instruction
Authors: Mansouri Fedoua , Hamzaoui Hafida
Published: February 2024

Abstract: The present study investigated enhancing undergraduates' epistemological beliefs by integrating epistemological insights into a regular university course using an immersion framework. It was conducted with second-year students in the Department of English Language and Cultures in an Algerian university. The 48-student group received a two-semester study skills course designed with built-in notions about the nature, construction, sources, and certainty of knowledge, along with the original course content. A 19-subject group received a traditional study skills course. Both samples' epistemological beliefs were measured using Baxter Magolda's epistemological reflection model before and after the treatment. A qualitative analysis of the data indicated a significantly greater increase in the sophistication of the treatment group's epistemological beliefs when compared to the control group. These results highlight the considerable potential that a curriculum design informed by personal epistemology research has to offer to all educational endeavors and, hence, to overall epistemological complexity in society. Recommendations are made for policymakers, instructional designers, and teachers.
COVID-19 Credit Policies around the World: Size, Scope, Costs, and Consequences
Authors: Hong Gee Hee , Lucas Deborah
Published: February 2024

ABSTRACT: Governments deployed credit policies on a historically unprecedented scale in response to the COVID-19 pandemic. We estimate the effective size of credit policies for seven large advanced economies in terms of the incremental resources provided to firms and households—a measure that allows aggregation across credit support, forbearance, and traditional fiscal policies but that does not appear in traditional government statistics. These estimates are used to reassess the absolute and relative size of different governments' policy interventions and to evaluate whether taking credit policies into account can help explain the cross section of macroeconomic outcomes. Incremental resources increase from an average 14.5 percent of 2020 GDP when only fiscal policies are considered to 22 percent of 2020 GDP when credit policies are also taken into account. Incorporating credit policies also reduces the cross-country variation in the total size of policy interventions. With regard to fiscal cost, fair value estimates for these credit support programs average 37 percent of principal, with wide variation depending on program features. We also discuss several related measurement issues, the financial regulatory changes that accommodated these programs, the pros and cons of the different types of credit policies, and how in principle budgetary costs should be calculated versus how governments account for credit policies in practice.
Outside and Outside: Plastic Passages—of Philosophy and Literature
Authors: Williams Tyler M.
Published: February 2024

Abstract: In Subjects That Matter , Namita Goswami attends to philosophy’s institutional and disciplinary failures to reconcile its identitarian claims to universality and reason with the feminist and postcolonial modes of thinking it traditionally keeps at bay. This essay places Goswami’s critique within a context of “the thought from outside,” which, beginning with Foucault’s reading of Blanchot, continuing through the geopolitics of Dussel’s philosophy of liberation, and prominent in Catherine Malabou’s conceptualization of plasticity, demonstrates how political critiques of philosophical hegemony contain an implicit theorization of “literature.” If “literature” gives voice to the thought from outside, does it in turn “decolonize” philosophy? If so, what itinerary of thought ought to follow the relationship between this literary decolonization of philosophy and its imbrication within the fold of philosophical thought? How to conceptualize the plastic relation between inside and outside, between center and periphery, without subordinating the latter to the hegemony of the former? This essay argues for a coherence between Goswami’s and Malabou’s materialist understandings of difference and a conceptualization of literature as an “outside” to philosophy that operates “excentrically” “inside” philosophy.
Stitching interferometry for long X-ray mirrors with lateral multi-shift-based absolute calibration
Authors: Zhou Guang , Wang Jiezhuo , Lei Weizheng , Dong Xiaohao , Wang Jie
Published: February 2024

To eliminate the reference mirror (REF) error of the Fizeau interferometer for measuring X-ray mirrors, the reference calibration method of lateral multi-shift measurements at the hundreds-micrometer pixel level is presented. Because of the high aspect ratio of long X-ray mirrors, by shifting the surface under test (SUT) along the tangential direction with integer multiple pixels, we extend the calibration method by using the difference between multiple shifted measurements to build an augmented multi-matrix for extracting the two-dimensional (2D) absolute surface. The method can be applied to arbitrary measurement regions of the test optics, and the measurement for both the benchmark sub-aperture and calibration of the REF is accomplished in a single measuring process. Furthermore, by adjusting the shift to the millimeter scale, reference-subtracted sub-apertures can be stitched to obtain the absolute 2D map of the X-ray mirror. Experimental results show that all the 2D discrepancies reach sub-nanometer repeatability, and comparison results between the long trace profiler (LTP) and the proposed method have been performed. Therefore, the results demonstrated that the proposed method meets the requirements of X-ray mirror measurements.
Full-range depth-encoded swept source polarization sensitive optical coherence tomography
Authors: Wu Tong , Shi Hengyu , Zhou Xinkang , Liu Youwen , Wang Ling , Shi Yaoyao , Wang Jiming , Lu Yuangang , Gu Xiaorong , He Chongjun
Published: February 2024

To realize the high sensitivity polarization sensitive optical coherence tomography (PS-OCT) imaging, a fiber-based full-range depth-encoded swept source PS-OCT (SS-PS-OCT) method is proposed. The two OCT images corresponding to the orthogonal polarized input light are located on the high sensitivity imaging region of the opposite sides relative to the zero optical path difference position. The full-range OCT images can be obtained by implementing the spatial phase modulation in the reference arm. The detection sensitivity of the system was measured experimentally to be 67 dB when the imaging depth approaching to 2 mm. The imaging of the biological tissue verifies that the proposed full-range depth-encoded SS-PS-OCT system has the higher detection sensitivity compared with the conventional depth encoded SS-PS-OCT system. Finally, we demonstrated the full-range high sensitivity phase retardation image of the bovine tendon and skin of human fingertip. The fiber-based full-range depth-encoded SS-PS-OCT method can realize the high sensitivity birefringence imaging in the medical diagnosis scenes with the requirements for long imaging range and high detection sensitivity.
Hyperspectral push-broom imager using a volume Bragg grating as an angular filter
Authors: Song Jung-Ho , Kwon Young-Hwan
Published: February 2024

A hyperspectral push-broom imager has been designed, constructed, and tested. The narrow angular selectivity of a weakly index modulated volume Bragg grating is utilized to replace the objective lens, slit, and collimating lens of a conventional slit-based hyperspectral push-broom imager. The imager comprises a dispersion grating, an angular filter grating, a focusing lens, and an image sensor. The imager has a field of view (FOV) of 17 degrees in the spatial direction, a spectral range from 400 nm to 900 nm, and a spectral resolution of 2.1 nm. The acquired hyperspectral data cubes are presented, and the influence of wavelength-dependent incident angle errors is analyzed.
Sharp bend and large FSR ring resonator based on the free-form curves on a thin-film lithium niobate platform
Authors: Liu Xingxu , Ruan Ziliang , Sun Shangsen , Guo Changjian , Chen Kaixuan , Zhu Ning , Liu Liu
Published: February 2024

Sharp bends are crucial for large-scale and high-density photonics integration on thin-film lithium niobate platform. In this study, we demonstrate low-loss (<0.05 dB) and sharp bends (Reff = 30 µm) using free-form curves with a 200-nm-thick slab and a rib height of 200 nm on x-cut lithium niobate. Employing the same design method, we successfully realize a compact fully-etched ring resonator with a remarkably large free spectral range of 10.36 nm experimentally. Notably, the equivalent radius of the ring resonator is a mere 15 µm, with a loaded Q factor reaching 2.2 × 104.
Mid-infrared optical frequency comb spectroscopy using an all-silica antiresonant hollow-core fiber
Authors: Tomaszewska-Rolla Dorota , Jaworski Piotr , Wu Dakun , Yu Fei , Foltynowicz Aleksandra , Krzempek Karol , Soboń Grzegorz
Published: February 2024

We present the first mid-infrared optical frequency comb spectrometer employing an absorption cell based on self-fabricated, all-silica antiresonant hollow-core fiber (ARHCF). The spectrometer is capable of measuring sub-mL sample volumes with 26 m interaction length and noise equivalent absorption sensitivity of 8.3 × 10−8 cm−1 Hz−1/2 per spectral element in the range of 2900 cm−1 to 3100 cm−1. Compared to a commercially available multipass cell, the ARHCF offers a similar interaction length in a 1000 times lower gas sample volume and a 2.8 dB lower transmission loss, resulting in better absorption sensitivity. The broad transmission windows of ARHCFs, in combination with a tunable optical frequency comb, make them ideal for multispecies detection, while the prospect of measuring samples in small volumes makes them a competitive technique to photoacoustic spectroscopy along with the robustness and prospect of coiling the ARHCFs open doors for miniaturization and out-of-laboratory applications.
Continuous wave terahertz detection using 1550 nm pumped nonlinear photoconductive GaAs metasurfaces
Authors: Seddon James , Hale Lucy , Jung Hyunseung , Norman Sarah , Brener Igal , Seeds Alwyn , Renaud Cyril , Mitrofanov Oleg
Published: February 2024

Terahertz (THz) continuous wave (CW) spectroscopy systems can offer extremely high spectral resolution over the THz band by photo-mixing high-performance telecommunications-band (1530-1565 nm) lasers. However, typical THz CW detectors in these systems use narrow band-gap photoconductors, which require elaborate material growth and generate relatively large detector noise. Here we demonstrate that two-step photon absorption in a nano-structured low-temperature grown GaAs (LT-GaAs) metasurface which enables switching of photoconductivity within approximately one picosecond. We show that LT-GaAs can be used as an ultrafast photoconductor in CW THz detectors despite having a bandgap twice as large as the telecommunications laser photon energy. The metasurface design harnesses Mie modes in LT GaAs resonators, whereas metallic electrodes of THz detectors can be designed to support an additional photonic mode, which further increases photoconductivity at a desired wavelength.
Transmission of signal and idler using optical parametric amplifier based on PPLN waveguide
Authors: Asobe Masaki , Wanifeni Ndadi , Kazama Takushi , Enbutsu Koji , Umeki Takeshi
Published: February 2024

In this study, we attempted the repeated transmission of S-band signals by compensating for the loss of the transmission fiber using an optical parametric amplifier (OPA) based on a periodically poled LiNbO3 waveguide. We examined and compared the two configurations. The first method involved wavelength conversion of the signal to an idler, while the second method amplified the signal itself. In the latter case, we demonstrated repeated transmissions using external dispersion compensation. In the former case, we demonstrated that it was possible not only to compensate for fiber loss but also to reduce the accumulation of dispersion in transmission fibers by utilizing spectral inversion.
Consideration of non-phase-matched nonlinear effects in the design of quasi-phase-matching crystals for optical parametric oscillators
Authors: Zheng Zihua , Tang Ziwen , Wei Zhiyi , Sun Jinghua
Published: February 2024

Femtosecond optical parametric oscillators (OPOs) are widely used in ultrafast nonlinear frequency conversion and quantum information. However, conventional OPOs based on quasi-phase-matching (QPM) crystals have many parasitic non-phase-matched processes which decrease the conversion efficiency. Here, we propose nine-wave coupled equations (NWCEs) to simulate all phase-matched and non-phase-matched interactions in QPM crystals to improve conventional three-wave coupled equations (TWCEs), especially for the situation of high intensity ultrashort pulses and complexly structured crystals. We discuss how to design the poling period of QPM crystal to maximize the conversion efficiency of signal light for a given OPO system. The simulation reveals that the OPO based on chirped periodically poled lithium niobate (CPPLN) with a certain chirp rate has higher signal wave conversion efficiency than that of a PPLN, and demonstrates that NWCEs illustrate more details of the pulse evolution in the OPO cavity. Starting from a CPPLN, an aperiodically poled lithium niobate (APPLN) design is available by modifying the domain lengths of the crystal and optimizing the OPO output power via dynamical optimization algorithm. The results show that by using a properly designed APPLN crystal, a 1600 nm OPO, when pumped by a femtosecond laser with 1030 nm central wavelength, 150 femtosecond pulse duration and 5 GW/cm2 power intensity at the focus, can achieve very efficient output with a signal light conversion efficiency of 50.6%, which is higher than that of PPLN (25.2%) and CPPLN (40.2%). The scheme in this paper will provide a reference for the design of nonlinear QPM crystals of OPOs and will help to understand the complex nonlinear dynamical behavior in OPO cavities.
Frequency drift noise suppression in φ-OFDR based on optical phase-locked loop
Authors: Yang Qiang , Xie Weilin , Yang Jiang , Wang Congfan , Zheng Xiang , Dong Yi
Published: February 2024

A φ-OFDR system based on optical phase-locked loop is proposed to suppress laser frequency drift noise. The results demonstrate a significant improvement of 16.1 dB in the signal-to-noise ratio (SNR) of the demodulated strain signal at 0.1 Hz compared with open-loop state.
Shape Sensing of Large-diameter Multi-core Fibers by DSS with Different Spatial Resolutions
Authors: Ogura Takafumi , Kobayashi Makito , Wada Masaki , Matsui Takashi , Nakajima Kazuhide , Koizumi Kengo , Murai Hitoshi , Murayama Hideaki
Published: February 2024

A multi-core fiber with a cladding diameter three times larger than conventional fibers was developed. Its shape sensing using two distributed strain sensing (DSS) systems with different spatial resolutions was formulated, simulated, experimented, and evaluated.
Shape sensing using a four-fiber ribbon with multi-core fibers and accuracy improvement
Authors: Nakamoto Shintaro , Ogura Takafumi , Kobayashi Makito , Wada Masaki , Matsui Takashi , Nakajima Kazuhide , Wada Ryota , Murayama Hideaki
Published: February 2024

A ribbonized fiber consisting of multi-core fibers and single-mode fibers was manufactured and applied to shape sensing. We showed that consideration of the irregular twist inherent in the ribbonaized MCF can improve the accuracy of shape sensing.
Fabrication of an Optical Fibre Biosensor towards Endoscopic Ultrasound Guided Pancreatic Cancer Detection
Authors: Garon Adam , Venkatachalapathy Suresh , Correia Ricardo , Korposh Sergiy , Morgan Steve , Lee Seung-Woo , Gordon George , Pramanik Bapan , Mata Alvaro , Aithal Guruprasad , Astbury Stuart
Published: February 2024

Mucin in pancreatic cyst fluid is linked to later development of pancreatic cancer. A fibre-tip surface plasmon resonance biosensor was fabricated to identify the presence and concentration of mucin in solution (sensitivity = 0.175 nm/(μg/ml)).
High-sensitivity fiber-tip photothermal gas sensor based on a 3D µ-printed Fabry-Pérot microcavity
Authors: Zhao Pengcheng , Krishnaiah Kummara Venkata , Guo Linhao , Li Taige , Ho Hoi Lut , Zhang A. Ping , Jin Wei
Published: February 2024

We report a miniature fiber-optic photothermal gas sensor based on a Fabry-Pérot microcavity directly 3D µ-printed on the end-face of a standard single-mode optical fiber. A detection limit of 0.4 parts-per-million for acetylene is demonstrated.
Long-distance large-capacity FBG sensor network with high-insertion-loss using high power broadband random fiber laser and high-order random lasing amplification
Authors: Rao Yun-Jiang , Deng Kang-Ye , Jie Song-Tao , Chen Yi-Cheng , Liu Yang , Dong Shi-Sheng
Published: February 2024

A long-distance (>80km) large-capacity (>500) FBG sensor network with high-insertion-loss (~30dB) induced by individually splicing FBG sensors is demonstrated using novel high-power broadband random fiber laser and random lasing amplification, for the first time.
Curvature and Torsion Monitoring using Time-Expanded ΦOTDR
Authors: Escobar-Vera Camilo , Soriano-Amat Miguel , Martins Hugo F. , Barrera David , Martin-Lopez Sonia , Gonzalez-Herraez Miguel , Fernández-Ruiz María R.
Published: February 2024

We present a curvature and torsion sensing architecture based on time-expanded phase-sensitive optical time-domain reflectometry (TE-ΦOTDR) with 10cm resolution, 125m range and 50Hz sampling rate. The proposal fills a performance gap in fiber-based shape sensors.
Machining learning assisted microstructured multimode optical fiber hydrophone
Authors: Zhang Wen Qi , Nguyen Linh Viet , Reja Mohammad Istiaque , Lancaster David G. , Warren-Smith Stephen
Published: February 2024

We built a fiber-optic hydrophone using a multimode microstructured pressure-sensitive fiber with a multi-fiber fanout. A neural network is used for signal post-processing and achieved better results than a commercial electric hydrophone.
Compact Resonant Fiber-Optic Gyroscope with a Broadband Light Source
Authors: Hu Junyi , Liu Shuang , Wang Yuxin , Ma Huilian
Published: February 2024

A compact broadband source-driven resonant fiber-optic gyroscope prototype is assembled and tested. The angle random walk is 0.0037°/√h and bias stability is 0.0069°/h for a 175-m long fiber coil of 5.7 cm diameter.
Narrow-Linewidth Semiconductor Laser With Highly Linear Frequency Modulation Response for Coherent Sensing
Authors: Boudreau S. , Rousseau G. , Robin D. , Riendeau M-C V. , Larochelle P. , Ayotte S. , Costin F. , Girard-Deschênes É. , Chrétien P. , Brochu G. , Dufour P. , Deschênes S. , Dionne P. , Rahim M. , Pakulski G. , Mohsin M. , Goodchild D. , Waldron P. , Paquette B. , Einabad O. Salehzadeh
Published: February 2024

A semiconductor DFB laser with a linewidth under 10 kHz, output power over 60 mW and linear frequency modulation span over 7 GHz is presented. Demonstrations of applications in lidar and distributed sensing are shown.
Strain and temperature dependences of Brillouin frequency shift in ZBLAN fiber
Authors: Zhu Guangtao , Goya Kenji , Noda Kohei , Lee Heeyoung , Mizuno Yosuke
Published: February 2024

The strain and temperature dependence coefficients of the Brillouin frequency shift in a ZBLAN (ZrF4-BaF2-LaF3-AlF3-NaF) fiber are -90.9 MHz/% and -1.6 MHz/K, respectively, which are approximately -0.16 and -1.3 times the values in silica fibers.
Characteristics of Hetero-core Fiber Optic Hydrogen Sensor with Multilayer Film Consisting of Palladium Nanoparticles and Poly-L-lysine
Authors: Nakamura Yuna , Watanabe Kazuhiro , Nishiyama Michiko
Published: February 2024

A hetero-core fiber optic hydrogen sensor with a multilayer film consisting of alternating layers of Poly-L-lysine and palladium nanoparticles was developed. The proposed sensor successfully enhanced the sensitivity to hydrogen gas detection keeping quick responsiveness.
Preliminary analysis of polarization effects in bent uncoupled-core multicore fibers
Authors: Cappelletti Martina , Orsuti Daniele , Vandborg Mads Holmark , Aitkulov Arman , Olmo Pablo Del , Schenato Luca , Magarotto Mirko , Santagiustina Marco , Antonelli Cristian , Mecozzi Antonio , Hayashi Tetsuya , Grüner-Nielsen Lars , Rishøj Lars Søgaard , Rottwitt Karsten , Galtarossa Andrea , Palmieri Luca
Published: February 2024

Uncoupled-core multicore fibers are becoming popular tools for many fields including optical fiber sensing. We analyze for the first time the polarization effects that take place when these fibers are bent.
0.01 Hz Low-frequency Acoustic Wave Detection over 92 km Sensing Fiber Based on Chirped-Pulse φ-OTDR
Authors: Yu Xinfeng , Guo Huapeng , Ye Zhigeng , Xu Pengbai , Yu Zhangjun , Wen Kunhua , Yang Jun , Qin Yuwen
Published: February 2024

0.01 Hz low-frequency acoustic wave detection over 92 km sensing fiber based on chirped-pulse φ-OTDR is demonstrated with distributed Raman amplification and 32 averages. The strain sensitivity is 8.5 nε/Hz1/2.
Online structure monitoring system of ship lock miter gate using FGB sensing technology
Authors: Li Na , Xie Yu , Wang Yiran , Liu Fang
Published: February 2024

The online monitoring system of the downstream miter gate of the Gezhouba No. 2 ship lock is built to achieve surveillance of the gate structure in strain, inclination, and crack by using FBG sensing technology.
The 15th-Year Measurement of PC-Constructed Bridge Main Girder Using Optical Fiber Sensors
Authors: Fujiwara Kotaro , Imai Michio , Taira Yohei , Kawabata Junichi , Ota Nobuyuki , Hayasaka Yota , Takanashi Daisuke
Published: February 2024

We show an experimental result of the durability of optical fiber sensors. After being installed for over 15 years, it successfully measured micro-strain caused by a person standing on the bridge.
FBG acoustic receivers for Guided Waves Structural Health Monitoring: sensitivity optimization and environmental drift compensation
Authors: Recoquillay Arnaud , Roussel Nicolas , Maurin Laurent , Blanchet Thomas , Deliancourt Etienne , Chapuis Bastien , Laffont Guillaume
Published: February 2024

Optical fibers are promising solutions for Structural Health Monitoring. A setup to measure ultrasounds under varying environmental conditions using Fiber Bragg Gratings is designed and tested during a bending test. The FBG length is also optimized.
Modelling the Signal-to-Noise Ratio of Frequency-scanned Brillouin Optical Time-Domain Reflectometry
Authors: Jin Simeng , Yang Zhisheng , Hong Xiaobin , Wu Jian
Published: February 2024

A signal-to-noise ratio model of frequency-scanned Brillouin optical time-domain reflectometry is established, enabling the accurate anticipation of system performance and the optimization of system parameters under any measurement condition.
Distributed Multi-Parameter Sensing Using Optic Ribbon of Ultra-Weak Chirp Fiber Bragg Gratings
Authors: Liu Cong , Wang Yu , Huang Wenhai , Tang Ke , Cheng Cheng , Tang Jianguan , Yang Minghong
Published: February 2024

A hybrid distributed optical fiber sensing system is proposed based on an optic ribbon of ultra-weak chirp fiber Bragg gratings (CFBGs) with adjacent distances of 5 m, which can realize simultaneous detection of dynamic vibration, temperature and static strain.
Modelling the Brillouin spectrum in Raman amplifier assisted Brillouin OTDR
Authors: Vandborg Mads , Mathew Neethu , Christensen Jesper , Joy Tomin , Allousch M. Ali , Marx Benjamin , Jostmeier Thorben , Grüner-Nielsen Lars , Rishøj Lars , Rottwitt Karsten
Published: February 2024

We model and measure the Brillouin power spectrum of Brillouin OTDR assisted by Raman amplification. We show how Raman pump depletion leads to measurement errors due to spectral translation of the Brillouin spectrum.
Copper ions sensing with aptamer-biofunctionalized bi-stack thin film interferometer on optical fiber tip
Authors: Śmietana Mateusz , Sikora Jakub , Martychowiec Agnieszka , Kwietniewski Norbert , Janik Monika , Koba Marcin , Olszewski Marcin
Published: February 2024

A thin-film interferometric structure obtained on fiber’s tip and biofunctionalized with aptamers is studied for label-free sensing of copper ions. As low as 100 nM Cu2+ has been detected with negligible sensitivity to Ni2+ ions.