bluuebunny/crossref_metadata_2025 huggingface dataset:
Associações entre gênero, classe e raça e participação nas aulas de Educação Física
Authors: Martins Mariana Zuaneti , Vasquez Vitor Lacerda , Mion Maria Paula Louzada
Published: February 2023

A participação nas aulas de Educação Física (EF) está associada à integração das pessoas às atividades física mesmo fora da escola. O objetivo deste artigo foi descrever e analisar as associações entre relações de gênero, classe e raça na participação nas aulas de EF no Brasil. Para tanto, utilizamos dados da Pesquisa Nacional de Saúde do Escolar (PeNSE), de 2015 e 2019, abrangendo um total de 272.520 estudantes entrevistados em 4.670 escolas. Por meio de boxplots, apontamos que meninas, negros/as e alunos de escolas públicas têm tempos semanais menores de atividade física na EF (TAEF) do que seus pares e que os valores de TAEF observados em 2019 são, em geral, inferiores aos de 2015. A comparação entre as duas pesquisas deu um caráter longitudinal a esta etapa do estudo. Esses resultados foram ratificados por meio de regressões lineares multivariadas, destacando que as relações de gênero tendem a produzir menores valores de TAEF para as meninas em comparação aos meninos, inclusive fixando os efeitos da regressão por escola. Neste caso, como não diferenciamos o ano de realização da PeNSE, a análise foi essencialmente transversal. Nossos resultados apontam que as desigualdades de participação nas aulas de EF reforçam o cenário observado fora da escola, não contribuindo para que a disciplina cumpra seu papel de integrar os/as jovens ao mundo da cultura corporal de movimento.
Subglottic Masses Revealing Rosai-Dorfman Disease
Authors: Snoussi Mouna , Derbel Abir , Hentati Yosr Hentati , Mnif Zeineb , Marzouk Sameh , Bahloul Zouheir
Published: February 2023

Rosai-Dorfman disease (RDD) is an uncommon lymphoproliferative disorder; RDD with oropharyngeal involvement is extremely rare, especially in adults. A 65-year-old woman with a complaint of progressive dyspnoea since 2016 presented with laryngeal involvement of RDD. A laryngoscopy examination revealed two solid, polypoid masses in the subglottic region, and a laryngeal biopsy concluded chronic in ammation without signs of malignancy. A second biopsy of axillary lymph nodes was performed, supporting the diagnosis of histiocytosis. The patient was treated with corticosteroids and then lost to follow-up. In 2019, she suffered from dyspnoea and a hoarse voice. Laryngoscopy examination showed a polypoid lesion causing airway obstruction at 70% and thickening of the lateral wall of the cavum. Physical examination found left axillary and submandibular adenopathy, and computed tomography revealed thickening of the supraglottic larynx narrowing the laryngeal pathway. Lymphadenectomy with immunohistochemical analysis revealed typical protein positive S-100 histiocytes and emperipolesis. The patient was treated with high doses of corticosteroids for six weeks then these were progressively decreased. The outcome was favourable; the laryngeal lesion disappeared after two weeks of treatment.
Hyperbaric and topical oxygen therapies in thermal burn wound healing: a review
Authors: Khan Nawal , Halaseh Faris F , Pillai Kathryn , Zaki Daniel P , Sayadi Lohrasb R , Widgerow Alan D
Published: February 2023

Objective:

This review aims to evaluate the effectiveness of the two most commonly used oxygen delivery methods for the treatment of thermal burn wound healing: hyperbaric oxygen therapy (HBOT) and topical oxygen therapy (TOT).

Method:

The PubMed database was searched for articles discussing the use of HBOT or TOT in the treatment of thermal burns.

Results:

The search yielded 43,406 articles, of which 28 (23 HBOT, 5 TOT) met the inclusion criteria. Both experimental and clinical studies have demonstrated conflicting results after treating thermal burns with HBOT or TOT. Overall, 14/23 studies demonstrated positive results for HBOT on the healing of burn wounds and associated complications, such as oedema and pain. Findings from these studies showed it can reduce morbidity and mortality in certain high-risk groups such as those with diabetes or extensive burns. Although the five studies (one human and four animal trials) reviewing TOT showed promising outcomes, this therapeutic modality has not been well investigated.

Conclusion:

Therapeutic use of HBOT in thermal burns has been popular in the past but its use remains controversial due to inconsistent results, serious side-effects, lack of convenience and high costs. The use of TOT in the management of burns needs further exploration by scientists and clinicians alike, in addition to the implementation of a standardised treatment protocol.
The Efficiency of Tailored Systems for Language Education: An App Based on Scientific Evidence and for Student-Centered Approach
Authors: Figueiredo Sandra
Published: February 2023

In the vulnerable and unstable contexts that characterize populations in mobility between countries, especially immigrants and refugees, the second language learning has assumed new traits of difficulty. To help the new generation of learners, mainly with origin in forced immigration, the mobile-assisted learning helps motivation for language learning and reduces anxiety related to language acquisition. Attending to this challenge educational scenario, this review study presents a literature systematic analysis and a concrete technology tool that advocates the student-centered approach. A mobile pedagogical plan was developed for the learning of European Portuguese as a Second Language and as a Foreign Language. A critical review of 38 studies was conducted to understand how the mobile-assisted learning responds to the inclusion and education, especially concerning minorities. Based on previous empirical data with 108 immigrants, we understand the type of tasks that new immigrants have more difficulty learning in Portuguese. It was developed as a mobile app for Android, IOS, computers and tablets: the GoGenius app. In mobile format, individuals can access fourteen themed units with a symmetrical game architecture. These games focused the tasks and themes with priority for new language learners who recently arrived in a hosting country. These units involve a consistent number of working hours that intentionally intend to complement to the contact hours that the subjects have in classroom contexts or in unstable communication contexts (daily communication). This technology project aims to match “tailored” psychological and technological resources. Flipped classroom approach showed how mobile-assisted learning reinforces the educational goals worldwide, specifically for language learning. However, mobile tools should be well structured and centered on students’ needs, especially with migration backgrounds.
Analysing Teachers’ Perception of the Try-Understand-Apply-Mastered Discovery Learning Processes in Vanuatu Using the Constructivist Grounded Theory Approach
Authors: Sawah Kency Obed , Kusaka Satoshi
Published: February 2023

Internal and external assessment instruments, such as the Vanuatu Standard Test of Achievements (VANSTA) and the Pacific Island Literacy and Numeracy Assessment (PILNA), reveal that mathematics achievements in the Republic of Vanuatu remain below the minimum standard. This study drew on the constructivist grounded theory approach to explore teachers' perspectives of the learning and teaching processes in mathematics education in the Republic of Vanuatu. Specifically, the focus was on the ‘I do-we do-you do’ approach of teaching, which is common in mathematics education in the country. Teachers' opinions about the current situation of mathematics education and possibilities for improving it were extracted using semi-structured interviews with 22 teachers from two randomly selected urban schools. Based on the constructivist grounded theory analysis, four major interlink themes were found. Overall, the findings show that mathematics achievements in the country can be improved through proven discovery-learning strategies for stimulating students' mathematical thinking in the 21st century, such as the ‘try-understand-apply-mastered’ (TUAM) discovery learning process.
Characteristics and risk factors of instrumentation failure following total en bloc spondylectomy
Authors: Shimizu Takaki , Kato Satoshi , Demura Satoru , Shinmura Kazuya , Yokogawa Noriaki , Kurokawa Yuki , Yoshioka Katsuhito , Murakami Hideki , Kawahara Norio , Tsuchiya Hiroyuki
Published: February 2023

Aims

The aim of this study was to investigate the incidence and characteristics of instrumentation failure (IF) after total en bloc spondylectomy (TES), and to analyze risk factors for IF.

Methods

The medical records from 136 patients (65 male, 71 female) with a mean age of 52.7 years (14 to 80) who underwent TES were retrospectively reviewed. The mean follow-up period was 101 months (36 to 232). Analyzed factors included incidence of IF, age, sex, BMI, history of chemotherapy or radiotherapy, tumour histology (primary or metastasis; benign or malignant), surgical approach (posterior or combined), tumour location (thoracic or lumbar; junctional or non-junctional), number of resected vertebrae (single or multilevel), anterior resection line (disc-to-disc or intravertebra), type of bone graft (autograft or frozen autograft), cage subsidence (CS), and local alignment (LA). A survival analysis of the instrumentation was performed, and relationships between IF and other factors were investigated using the Cox regression model.

Results

A total of 44 patients (32.4%) developed IF at a median of 31 months (interquartile range 23 to 74) following TES. Most IFs were rod fractures preceded by a mean CS of 6.1 mm (2 to 18) and LA kyphotic enhancement of 10.8° (-1 to 36). IF-free survival rates were 75.8% at five years and 56.9% at ten years. The interval from TES to IF peaked at two to three years postoperatively and continued to occur over a period of time thereafter; the early IF-developing group had greater CS at one month postoperatively (CS1M) and more lumbar TES. CS1M ≥ 3 mm and sole use of frozen autografts were identified as independent risk factors for IF.

Conclusion

IF is a common complication following TES. We have demonstrated that robust spinal reconstruction preventing CS, and high-quality bone grafting are necessary for successful reconstruction. Cite this article: Bone Joint J 2023;105-B(2):172–179.
The management of developmental dysplasia of the hip in children aged under three months
Authors: Aarvold Alexander , Perry Daniel C. , Mavrotas Jason , Theologis Tim , Katchburian Marcos ,   on behalf of the BSCOS DDH Consensus Group
Published: February 2023

Aims

A national screening programme has existed in the UK for the diagnosis of developmental dysplasia of the hip (DDH) since 1969. However, every aspect of screening and treatment remains controversial. Screening programmes throughout the world vary enormously, and in the UK there is significant variation in screening practice and treatment pathways. We report the results of an attempt by the British Society for Children’s Orthopaedic Surgery (BSCOS) to identify a nationwide consensus for the management of DDH in order to unify treatment and suggest an approach for screening.

Methods

A Delphi consensus study was performed among the membership of BSCOS. Statements were generated by a steering group regarding aspects of the management of DDH in children aged under three months, namely screening and surveillance (15 questions), the technique of ultrasound scanning (eight questions), the initiation of treatment (19 questions), care during treatment with a splint (ten questions), and on quality, governance, and research (eight questions). A two-round Delphi process was used and a consensus document was produced at the final meeting of the steering group.

Results

A total of 60 statements were graded by 128 clinicians in the first round and 132 in the second round. Consensus was reached on 30 out of 60 statements in the first round and an additional 12 in the seond. This was summarized in a consensus statement and distilled into a flowchart to guide clinical practice.

Conclusion

We identified agreement in an area of medicine that has a long history of controversy and varied practice. None of the areas of consensus are based on high-quality evidence. This document is thus a framework to guide clinical practice and on which high-quality clinical trials can be developed. Cite this article: Bone Joint J 2023;105-B(2):209–214.
Universal screening may reduce the incidence of late diagnosis of developmental dysplasia of the hip
Authors: Cheok Tim , Smith Thomas , Wills Kenneth , Jennings Matthew P. , Rawat Jaideep , Foster Bruce
Published: February 2023

Aims

We investigated the prevalence of late developmental dysplasia of the hip (DDH), abduction bracing treatment, and surgical procedures performed following the implementation of universal ultrasound screening versus selective ultrasound screening programmes.

Methods

A systematic search of PubMed, Embase, The Cochrane Library, OrthoSearch, and Web of Science from the date of inception of each database until 27 March 2022 was performed. The primary outcome of interest was the prevalence of late detection of DDH, diagnosed after three months. Secondary outcomes of interest were the prevalence of abduction bracing treatment and surgical procedures performed in childhood for dysplasia. Only studies describing the primary outcome of interest were included.

Results

A total of 31 studies were identified, of which 13 described universal screening and 20 described selective screening. Two studies described both. The prevalence of late DDH was 0.10 per 1,000 live births (95% confidence interval (CI) 0.00 to 0.39) in the universal screening group and 0.45 per 1,000 live births (95% CI 0.31 to 0.61) in the selective screening group. Abduction bracing treatment was performed on 55.54 per 1,000 live births (95% CI 24.46 to 98.15) in the universal screening group versus 0.48 per 1,000 live births (95% CI 0.07 to 1.13) in the selective screening group. Both the universal and selective screening groups had a similar prevalence of surgical procedures in childhood for dysplasia being performed (0.48 (95% CI 0.32 to 0.63) vs 0.49 (95% CI 0.31 to 0.71) per 1,000 live births, respectively).

Conclusion

Universal screening showed a trend towards lower prevalence of late DDH compared to selective screening. However, it was also associated with a significant increase in the prevalence of abduction bracing without a significant reduction in the prevalence of surgical procedures in childhood for dysplasia being performed. High-quality studies comparing both treatment methods are required, in addition to studies into the natural history of missed DDH. Cite this article: Bone Joint J 2023;105-B(2):198–208.
Health-related quality of life in patients 40 years after diagnosis of an idiopathic scoliosis
Authors: Ragborg Lærke C. , Dragsted Casper , Ohrt-Nissen Søren , Andersen Thomas , Gehrchen Martin , Dahl Benny
Published: February 2023

Aims

Only a few studies have investigated the long-term health-related quality of life (HRQoL) in patients with an idiopathic scoliosis. The aim of this study was to investigate the overall HRQoL and employment status of patients with an idiopathic scoliosis 40 years after diagnosis, to compare it with that of the normal population, and to identify possible predictors for a better long-term HRQoL.

Methods

We reviewed the full medical records and radiological reports of patients referred to our hospital with a scoliosis of childhood between April 1972 and April 1982. Of 129 eligible patients with a juvenile or adolescent idiopathic scoliosis, 91 took part in the study (71%). They were evaluated with full-spine radiographs and HRQoL questionnaires and compared with normative data. We compared the HRQoL between observation (n = 27), bracing (n = 46), and surgical treatment (n = 18), and between thoracic and thoracolumbar/lumbar (TL/L) curves.

Results

The mean time to follow-up was 40.8 years (SD 2.6) and the mean age of patients was 54.0 years (SD 2.7). Of the 91 patients, 86 were female (95%) and 51 had a main thoracic curve (53%). We found a significantly lower HRQoL measured on all the Scoliosis Research Society 22r instrument (SRS-22r) subdomains (p < 0.001) with the exception of mental health, than in an age-matched normal population. Incapacity to work was more prevalent in scoliosis patients (21%) than in the normal population (11%). The median SRS-22r subscore was 4.0 (interquartile range (IQR) 3.3 to 4.4) for TL/L curves and 4.1 (IQR 3.8 to 4.4) for thoracic curves (p = 0.300). We found a significantly lower self-image score for braced (median 3.6 (IQR 3.0 to 4.0)) and surgically treated patients (median 3.6 (IQR 3.2 to 4.3)) than for those treated by observation (median 4.0 (IQR 4.1 to 4.8); p = 0.010), but no statistically significant differences were found for the remaining subdomains.

Conclusion

In this long-term follow-up study, we found a significantly decreased HRQoL and capacity to work in patients with an idiopathic scoliosis 40 years after diagnosis. Cite this article: Bone Joint J 2023;105-B(2):166–171.
Periprosthetic hip infection in octogenarians
Authors: Karczewski Daniel , Schönnagel Lukas , Hipfl Christian , Akgün Doruk , Hardt Sebastian
Published: February 2023

Aims

Periprosthetic joint infection (PJI) in total hip arthroplasty in the elderly may occur but has been subject to limited investigation. This study analyzed infection characteristics, surgical outcomes, and perioperative complications of octogenarians undergoing treatment for PJI in a single university-based institution.

Methods

We identified 33 patients who underwent treatment for PJIs of the hip between January 2010 and December 2019 using our institutional joint registry. Mean age was 82 years (80 to 90), with 19 females (57%) and a mean BMI of 26 kg/m2 (17 to 41). Mean American Society of Anesthesiologists (ASA) grade was 3 (1 to 4) and mean Charlson Comorbidity Index was 6 (4 to 10). Leading pathogens included coagulase-negative Staphylococci (45%) and Enterococcus faecalis (9%). Two-stage exchange was performed in 30 joints and permanent resection arthroplasty in three. Kaplan-Meier survivorship analyses were performed. Mean follow-up was five years (3 to 7).

Results

The two-year survivorship free of any recurrent PJI was 72% (95% confidence interval (CI) 56 to 89; 18 patients at risk). There were a total of nine recurrent PJIs at a mean of one year (16 days to eight years), one for the same pathogen as at index infection. One additional surgical site infection was noted at two weeks, resulting in a 69% (95% CI 52 to 86; 17 patients at risk) survivorship free of any infection at two years. There were two additional revisions for dislocations at one month each. As such, the two-year survivorship free of any revision was 61% (95% CI 42 to 80; 12 patients at risk). In addition to the aforementioned revisions, there was one additional skin grafting for a decubitus ulcer, resulting in a survivorship free of any reoperation of 54% (95% CI 35 to 73; ten patients at risk) at two years. Mean Clavien-Dindo score of perioperative complications was two out of five, with one case of perioperative death noted at six days.

Conclusion

Octogenarians undergoing surgery for PJI of the hip are at low risk of acute mortality, but are at moderate risk of other perioperative complications. One in two patients will undergo a reoperation within two years, with 70% attributable to recurrent infections. Cite this article: Bone Joint J 2023;105-B(2):135–139.
Compatible bedfellows? Engaged scholarship entrepreneurship and policy impact
Authors: Trehan Kiran
Published: February 2023

Background:

This comment piece responds to points raised by Steve Johnson in ‘The policy impact of entrepreneurship research: challenging received wisdom’ (Evidence & Policy, Early view, https://doi.org/10.1332/174426422X16596963542147).

Aims and objectives:

The practical purpose of this commentary is to illustrate and discuss the relationship between entrepreneurship research, implementation, and policy impact.

Commentary:

The commentary offers insights into how researchers can make a difference to policy learning through engaged scholarship. Three contributions to knowledge on entrepreneurship research and policy learning are presented.

Findings:

First, the commentary develops the connection between engaged scholarship, entrepreneurship research and policy learning by highlighting the dynamics that underpin and sustain engaged scholarship. Second, entrepreneurship research and policy impact are brought into contact with engaged scholarship to develop practical relevance. Third, I illuminate the paradox between the theory and practise of policy integration.

Discussion and conclusions:

Building on the ideas presented by Steve Johnson in his paper, ‘The policy impact of entrepreneurship research: challenging received wisdom’, I address the gap between conceptualisation of entrepreneurship and the dynamics of implementation and policy learning, which all too often remains implicit within extant studies in entrepreneurship research.
Emotional labour in digital diplomacy: perceptions and challenges for European diplomats
Authors: Hedling Elsa
Published: February 2023

Social media are increasingly important tools in diplomacy. Diplomats are expected to use social media platforms such as Twitter, Facebook and Instagram to communicate with each other and with both the domestic and international publics. This form of communication involves displaying positive emotions to generate attention in a competitive information environment. Emotions are essential to managing perceptions, conveying signals and safeguarding state reputations in traditional diplomacy. Commercial demands of online performance, however, activate new dimensions and challenges in the management of emotions in diplomacy. As digital disinformation and populist campaigns have transgressed the boundaries of domestic public debate, diplomats must also display emotional restraint to contain and counter such influence. This article analyses how diplomats perceive the demands of digital diplomacy and how emotions are engaged in their efforts to perform competently both online and offline. The study draws on fieldwork and interviews with 13 European diplomats as well as document analysis of handbooks and training material used to transfer ‘emotional communication skills’ to diplomats. The study findings suggest that the demands of digital diplomacy are challenging traditional enactments of ‘the good diplomat’. In addition to the tensions between outreach and countering communication practices, the emotional labour in digital diplomacy extends beyond what we see on social media. Diplomats perceive the expectations of constant performance online to at times conflict with their professional role offline.
Performance analysis of SPAD-based optical wireless communication with OFDM
Authors: Huang Shenjie , Li Yichen , Chen Cheng , Soltani Mohammad Dehghani , Henderson Robert , Safari Majid , Haas Harald
Published: February 2023

In recent years, there has been a growing interest in the use of a single-photon avalanche diode (SPAD) in optical wireless communication (OWC). The SPAD operates in the Geiger mode and can act as a photon counting receiver obviating the need for a transimpedance amplifier. Although a SPAD receiver can provide higher sensitivity compared to traditional linear photodetectors, it suffers from dead-time-induced nonlinearity. To improve the data rates of SPAD-based OWC systems, optical orthogonal frequency division multiplexing (OFDM) can be employed. This paper provides a comprehensive theoretical analysis of the SPAD-based OWC systems using direct-current-biased optical OFDM signaling considering the effects of signal clipping, SPAD nonlinearity, and signal-dependent shot noise. An equivalent additive Gaussian noise channel model is proposed to describe the performance of the SPAD-based OFDM system. The statistics of the proposed channel model and the analytical expressions of the signal-to-noise ratio and bit error rate are derived in closed forms. By means of extensive numerical results, the impact of the unique receiver nonlinearity on the system performance is investigated. The results demonstrate new insights into different optical power regimes of reliable operation for SPAD-based OFDM systems even well beyond the SPAD saturation level.
Evaluation of the Sagnac-loop laser frequency stabilization to sub-Doppler spectral lines
Authors: Hasegawa Taro
Published: February 2023

Laser frequency stability locked to D2 transition of 85Rb at 780 nm by the Sagnac-loop stabilization scheme was evaluated using the heterodyne measurement with an optical frequency comb. This scheme does not require modulation and magnetic field to generate the feedback error signal. Therefore, the setup for the laser frequency stabilization is simple. Because of the mechanical stability of the Sagnac interferometer, the dispersion of atom transition, which is used as an error signal for feedback loop, can be observed with negligibly small effects of mechanical fluctuations. In the experiment, the Allan variance for relative frequency uncertainty was 2.6×10−12 over 64 s averaging.
Method for retrieving range-resolved aerosol microphysical properties from polarization lidar measurements
Authors: Huang Zhongwei , Dong Qingqing , Chen Bin , Wang Tianhe , Bi Jianrong , Zhou Tian , Alam Khan , Shi Jinsen , Zhang Shuang
Published: February 2023

Aerosol microphysical properties, such as volume concentration (VC) and effective radius (ER), are of great importance to evaluate their radiative forcing and impacts on climate change. However, range-resolved aerosol VC and ER still cannot be obtained by remote sensing currently except for the column-integrated one from sun-photometer observation. In this study, a retrieval method of range-resolved aerosol VC and ER is firstly proposed based on the partial least squares regression (PLSR) and deep neural networks (DNN), combining polarization lidar and collocated AERONET (AErosol RObotic NETwork) sun-photometer observations. The results show that the measurement of widely-used polarization lidar can be reasonably used to derive the aerosol VC and ER, with the determination coefficient (R2) of 0.89 (0.77) for VC (ER) by use of the DNN method. Moreover, it is proven that the lidar-based height-resolved VC and ER at near-surface are well consistent with independent observations of collocated Aerodynamic Particle Sizer (APS). Additionally, we found that there are significant diurnal and seasonal variations of aerosol VC and ER in the atmosphere at Semi-Arid Climate and Environment Observatory of Lanzhou University (SACOL). Compared with columnar ones from the sun-photometer observation, this study provides a reliable and practical way to obtain full-day range-resolved aerosol VC and ER from widely-used polarization lidar observation, even under cloud conditions. Moreover, this study also can be applied to long-term observations by current ground-based lidar networks and spaceborne CALIPSO lidar, aiming to further evaluate aerosol climatic effects more accurately.
Polarized angle-resolved spectral reflectometry for real-time ultra-thin film measurement
Authors: Wang Jian , Peng Lihua , Zhai Fuqi , Tang Dawei , Gao Feng , Zhang Xiangchao , Chen Rong , Zhou Liping , Jiang Xiangqian Jane
Published: February 2023

We propose a polarized, angle-resolved spectral (PARS) reflectometry for simultaneous thickness and refractive-index measurement of ultra-thin films in real time. This technology acquires a two-dimensional, angle-resolved spectrum through a dual-angle analyzer in a single shot by radially filtering the back-focal-plane image of a high-NA objective for dispersion analysis. Thus, film parameters, including thickness and refractive indices, are precisely fitted from the hyper-spectrum in angular and wavelength domains. Through a high-accuracy spectral calibration, a primary PARS system was built. Its accuracy was carefully verified by testing a set of SiO2 thin films of thicknesses within two µm grown on monocrystalline-Si substrates against a commercial spectroscopic ellipsometer. Results show that the single-shot PARS reflectometry results in a root-mean-square absolute accuracy error of ∼1 nm in film thickness measurement without knowing its refractive indices.
Statistical perception of the chaotic fabrication error and the self-adaptive processing decision in ultra-precision optical polishing
Authors: Li Hanjie , Wan Songlin , Niu Zhenqi , Guo Hao , Zhang Lanya , Lu Qing , Wei Chaoyang , Shao Jianda
Published: February 2023

Subaperture polishing is a key technique for fabricating ultra-precision optics. However, the error source complexity in the polishing process creates large fabrication errors with chaotic characteristics that are difficult to predict using physical modelling. In this study, we first proved that the chaotic error is statistically predictable and developed a statistical chaotic-error perception (SCP) model. We confirmed that the coupling between the randomness characteristics of chaotic error (expectation and variance) and the polishing results follows an approximately linear relationship. Accordingly, the convolution fabrication formula based on the Preston equation was improved, and the form error evolution in each polishing cycle for various tools was quantitatively predicted. On this basis, a self-adaptive decision model that considers the chaotic-error influence was developed using the proposed mid- and low-spatial-frequency error criteria, which realises the automatic decision of the tool and processing parameters. An ultra-precision surface with equivalent accuracy can be stably realised via proper tool influence function (TIF) selection and modification, even for low-deterministic level tools. Experimental results indicated that the average prediction error in each convergence cycle was reduced to 6.14%. Without manual participation, the root mean square(RMS) of the surface figure of a ϕ100-mm flat mirror was converged to 1.788 nm with only robotic small-tool polishing, and that of a ϕ300-mm high-gradient ellipsoid mirror was converged to 0.008 λ. Additionally, the polishing efficiency was increased by 30% compared with that of manual polishing. The proposed SCP model offers insights that will help achieve advancement in the subaperture polishing process.
Light field displays with computational vision correction for astigmatism and high-order aberrations with real-time implementation
Authors: Qiu Yuqing , Zhao Zhiqing , Yang Jinglan , Cheng Yunfan , Liu Yi , Yang Bo-Ru , Qin Zong
Published: February 2023

Vision-correcting near-eye displays are necessary concerning the large population with refractive errors. However, varifocal optics cannot effectively address astigmatism (AST) and high-order aberration (HOAs); freeform optics has little prescription flexibility. Thus, a computational solution is desired to correct AST and HOA with high prescription flexibility and no increase in volume and hardware complexity. In addition, the computational complexity should support real-time rendering. We propose that the light field display can achieve such computational vision correction by manipulating sampling rays so that rays forming a voxel are re-focused on the retina. The ray manipulation merely requires updating the elemental image array (EIA), being a fully computational solution. The correction is first calculated based on an eye’s wavefront map and then refined by a simulator performing iterative optimization with a schematic eye model. Using examples of HOA and AST, we demonstrate that corrected EIAs make sampling rays distributed within ±1 arcmin on the retina. Correspondingly, the synthesized image is recovered to nearly as clear as normal vision. We also propose a new voxel-based EIA generation method considering the computational complexity. All voxel positions and the mapping between voxels and their homogeneous pixels are acquired in advance and stored as a lookup table, bringing about an ultra-fast rendering speed of 10 ms per frame with no cost in computing hardware and rendering accuracy. Finally, experimental verification is carried out by introducing the HOA and AST with customized lenses in front of a camera. As a result, significantly recovered images are reported.
20 MHz resonant photodetector for the homodyne measurement of picosecond pulsed squeezed light
Authors: Li Zhihao , Liu Jun , Guo Fengjuan , Zhao Lujie , Qin Zhongzhong , Ma Rong
Published: February 2023

A high-performance resonant balanced homodyne detector is a key element for the measurement of picosecond pulsed squeezed light, which is an important quantum resource in quantum-enhanced microscopic imaging. In this paper, we design and demonstrate a resonant photodetector for homodyne measurement with a maximum signal-to-noise ratio of 22.42 dB at resonant frequency of 20 MHz. Using this detector to pulsed regime, a maximum signal-to-noise ratio at resonant frequency is 10.02 dB, where a 40 dB subtraction capability at 80 MHz repetition rate of pulsed laser is obtained. With this design, the quantum noise of picosecond pulsed squeezed light is measured and the best squeezing level −1.7 dB below the shot noise level is clearly observed at 20 MHz.
Ultrastrong coupling in Super Yellow polymer microcavity and development of highly efficient polariton light-emitting diodes and light-emitting transistors
Authors: Chang Jui-Fen , ZHENG YU-CHEN , CHIANG CHI-YU , HUANG CHEN-KANG , Jaing Cheng-Chung
Published: February 2023

We present detailed studies on exciton-photon coupling and polariton emission based on a poly(1,4-phenylenevinylene) copolymer, Super Yellow (SY), in a series of optical microcavities and optoelectronic devices, including light-emitting diode (LED) and light-emitting transistor (LET). We show that sufficiently thick SY microcavities can generate ultrastrong coupling with Rabi splitting energies exceeding 1 eV and exhibit spectrally narrow, nearly angle-independent photoluminescence following lower polariton (LP) mode dispersion. When the microcavity is designed with matched LP low-energy state and exciton emission peak for radiative pumping, the conversion efficiency from exciton to polariton emission can reach up to 80%. By introducing appropriate injection layers in a SY microcavity and optimizing the cavity design, we further demonstrate a high-performance ultrastrongly coupled SY LED with weakly dispersive electroluminescence along LP mode and a maximum external quantum efficiency (EQE) of 2.8%. Finally, we realize an ultrastrongly coupled LET based on vertical integration of a high-mobility ZnO transistor and a SY LED in a microcavity, which enables a large switching ratio, uniform emission in the ZnO pattern, and LP mode emission with a maximum EQE of 2.4%. This vertical LET addresses the difficulties of achieving high emission performance and precisely defining the emission area in typical planar LETs, and opens up the possibility of applying various strongly coupled emitters for advanced polariton devices and high-resolution applications.
The deep-sea camera with three detectors based on triple-prism
Authors: quan xiangqian , Wei Yucong , Li Zizheng , LIU Kaibin , Li Bo , li yun , Yan Peng
Published: February 2023

The deep-sea photogrammetry is an important means of deep-sea exploration. Due to the attenuation of light in water, deep-sea camera systems need deep-sea lamps to provide the light source, which consume lots of energy. So the light utilization efficiency of deep-sea optical camera affects the load capacity and operation capacity of deep-sea platforms. In addition, due to the non-linearity of light attenuation in different wavelength, the deep-sea optical images generally suffer from color deviation with tending to be blue and green, which leads to the decline of operation efficiency and the increase of scientific research cost in deep-sea exploration. In order to improve the light utilization efficiency and enhance the color restoration of deep-sea camera, we proposed, designed and developed a deep-sea camera with three detectors based on triple-prism (TD&TP-DSC) for the first time. In this camera system, three detectors combined with triple-prism aimed to improve the light utilization efficiency, and the coatings on the triple-prism were designed for gating waveband to improve the color restoration. With carrying out a series of experiments in water tank, water pool, Qiandao Lake and the South China Sea, the low-light performance and color restoration of TD&TP-DSC were certified. The experimental result showed that TD&TP-DSC had advantages over the common deep-sea camera, which provided enlightenment for the development of new generation deep-sea camera system.
Graded-index core-based polarization dependence beam splitters realized with symmetric polymer directional couplers
Authors: Rasel MD Omar Faruk , Tasnim Fariha , Afsary Noor , Ishigure Takaaki
Published: February 2023

In this paper, we design and demonstrate polymer-based polarization dependence beam splitters realized with graded-index (GI) parabolic directional couplers at 1550 nm. We investigate these directional couplers by using the beam propagation method (BPM) and the RSoft CAD BeamPROP solver is used for model design and characterization. We investigate the splitting ratio of 50:50 and 100:0 of these beam splitters for both TE and TM modes. In particular, the 50:50 beam splitters exhibit an output efficiency of 95% due to the absence of polarization. However, in presence of the polarization effect, the polarization dependency is analyzed and manipulated successfully, and the input intensity increases by approximately 98% at an incident angle of 31° due to the polarized launch field. Moreover, the 100:0 beam splitters act as the switching devices realized with GI polymer directional couplers. The insertion losses of the GI splitters are 0.162 dB and 0.186 dB, while the excess losses are 0.148 dB and 0.149 dB for TE and TM modes, respectively. Also, the polarization extinction ratio (PER) of the 100:0 beam splitters is >25 dB and >20 dB for TE and TM modes, respectively.
Intra-cavity laser-assisted solar-energy conversion
Authors: Jiménez Ignacio , Wallentowitz Sascha , Seifert Birger , Volkmann Ulrich , Díaz-Droguett Donovan , Cabrera A.L. , Gence Loïk
Published: February 2023

It is shown how to efficiently convert solar into electrical energy,
taking advantage of laser amplification and intra-cavity use of a
low-efficiency converter. The latter may consist of a low-efficiency
transparent photovoltaic cell or a thermoelectric cell integrated
into a metallic laser-cavity mirror, constituting a minor intra-cavity
loss for the laser operation. The overall power conversion efficiency
is derived and discussed for a variety of current solid-state laser materials. It is shown that power conversion efficiencies comparable with commercial silicon photovoltaic cells are obtained with current standard laser materials.
Using virtual simulations of future extreme weather events to communicate climate change risk
Authors: van Gevelt Terry , McAdoo Brian G. , Yang Jie , Li Linlin , Williamson Fiona , Scollay Alex , Lam Aileen , Chan Kwan Nok , Switzer Adam D.
Published: February 2023

Virtual simulations of future extreme weather events may prove an effective vehicle for climate change risk communication. To test this, we created a 3D virtual simulation of a future tropical cyclone amplified by climate change. Using an experimental framework, we isolated the effect of our simulation on risk perceptions and individual mitigation behaviour for a representative sample (n = 1507) of the general public in Hong Kong. We find that exposure to our simulation is systematically associated with a relatively small decrease in risk perceptions and individual mitigation behaviour. We suggest that this is likely due to climate change scepticism, motivation crowding, geographical and temporal distance, high-risk thresholds, feelings of hopelessness, and concerns surrounding the immersiveness of the virtual simulation.
From global recommendations to (in)action: A scoping review of the coverage of companion of choice for women during labour and birth
Authors: Bohren Meghan A. , Hazfiarini Alya , Vazquez Corona Martha , Colomar Mercedes , De Mucio Bremen , Tunçalp Özge , Portela Anayda
Published: February 2023

Women greatly value and benefit from the presence of someone they trust to support them throughout labour and childbirth (‘labour companion of choice’). Labour companionship improves maternal and perinatal outcomes, including enhancing physiological labour and birth experiences. Despite clear benefits, implementation is slow. We conducted a scoping review to assess coverage and models of labour companionship, including quantitative studies reporting coverage of labour companionship in any level health facility globally. We searched MEDLINE, CINAHL, and Global Health from 1 January 2010–14 December 2021. We extracted data on study design, labour companionship coverage, timing and type of companions allowed, and recoded data into categories for comparison across studies. We included data from a maternal health sentinel network of hospitals in Latin America, using descriptive statistics to assess coverage among 120,581 women giving birth in these sites from April 2018-April 2022. In the scoping review, we included 77 studies from 27 countries. There was wide variation in the coverage of labour companionship: almost one-third of studies reported coverage less than 40%, and one-third of studies reported coverage between 40–80%. Husbands or partners were the most frequent companion (37.7%, 29/77), followed by family member or friend (gender not specified) (32.5%, 25/77), family member or friend (female-only) (13.0%, 10/77). Across nine sentinel hospitals in five Latin American countries, there was variation in coverage, with no companion at any time ranging from 14.9%-93.8%. Despite the well-known benefits and factors affecting implementation of labour companionship, more work is needed to improve equitable coverage. Concerted efforts are needed to engage with communities, health workers, health managers, and policy-makers to establish policies, address implementation barriers, and integrate data on coverage into perinatal records and quality processes to ensure that all women have access. Harmonized reporting of labour companionship would greatly enhance understanding at global level.
Optimal training of integer-valued neural networks with mixed integer programming
Authors: Thorbjarnarson Tómas , Yorke-Smith Neil
Published: February 2023

Recent work has shown potential in using Mixed Integer Programming (MIP) solvers to optimize certain aspects of neural networks (NNs). However the intriguing approach of training NNs with MIP solvers is under-explored. State-of-the-art-methods to train NNs are typically gradient-based and require significant data, computation on GPUs, and extensive hyper-parameter tuning. In contrast, training with MIP solvers does not require GPUs or heavy hyper-parameter tuning, but currently cannot handle anything but small amounts of data. This article builds on recent advances that train binarized NNs using MIP solvers. We go beyond current work by formulating new MIP models which improve training efficiency and which can train the important class of integer-valued neural networks (INNs). We provide two novel methods to further the potential significance of using MIP to train NNs. The first method optimizes the number of neurons in the NN while training. This reduces the need for deciding on network architecture before training. The second method addresses the amount of training data which MIP can feasibly handle: we provide a batch training method that dramatically increases the amount of data that MIP solvers can use to train. We thus provide a promising step towards using much more data than before when training NNs using MIP models. Experimental results on two real-world data-limited datasets demonstrate that our approach strongly outperforms the previous state of the art in training NN with MIP, in terms of accuracy, training time and amount of data. Our methodology is proficient at training NNs when minimal training data is available, and at training with minimal memory requirements—which is potentially valuable for deploying to low-memory devices.
Longitudinal study on MRI and neuropathological findings: Neither DSC-perfusion derived rCBVmax nor vessel densities correlate between newly diagnosed and progressive glioblastoma
Authors: Steidl Eike , Filipski Katharina , Hattingen Elke , Steinbach Joachim P. , Maurer Gabriele D.
Published: February 2023

Introduction

When evaluating MRIs for glioblastoma progression, previous scans are usually included into the review. Nowadays dynamic susceptibility contrast (DSC)-perfusion is an essential component in MR-diagnostics of gliomas, since the extent of hyperperfusion upon first diagnosis correlates with gene expression and survival. We aimed to investigate if this initial perfusion signature also characterizes the glioblastoma at time of progression. If so, DSC-perfusion data from the initial diagnosis could be of diagnostic benefit in follow-up assessments.

Methods

We retrospectively identified 65 patients with isocitrate dehydrogenase wildtype glioblastoma who had received technically identical DSC-perfusion measurements at initial diagnosis and at time of first progression. We determined maximum relative cerebral blood volume values (rCBVmax) by standardized re-evaluation of the data including leakage correction. In addition, the corresponding tissue samples from 24 patients were examined histologically for the maximum vessel density within the tumor. Differences (paired t-test/ Wilcoxon matched pairs test) and correlations (Spearman) between the measurements at both timepoints were calculated.

Results

The rCBVmax was consistently lower at time of progression compared to rCBVmax at time of first diagnosis (p < .001). There was no correlation between the rCBVmax values at both timepoints (r = .12). These findings were reflected in the histological examination, with a lower vessel density in progressive glioblastoma (p = .01) and no correlation between the two timepoints (r = -.07).

Conclusion

Our results suggest that the extent of hyperperfusion in glioblastoma at first diagnosis is not a sustaining tumor characteristic. Hence, the rCBVmax at initial diagnosis should be disregarded when reviewing MRIs for glioblastoma progression.
Scales of transformations—Modelling settlement and land-use dynamics in late antique and early medieval Basel, Switzerland
Authors: Kempf Michael , Depaermentier Margaux L. C.
Published: February 2023

Multicomponent environmental models have increasingly found their way into archaeological research. Mostly, these models aim to understand human patterns as a result of past climatic and environmental conditions over long-term periods. However, major limitations are the low spatial and temporal resolution of the environmental data, and hence the rather static model output. Particular challenges are thus the number of chosen variables, the comprehensiveness of the explanatory parameters, and the integration of socio-cultural decision-making into the model. Here, we present a novel approach to generate annually resolved landcover variability using a broad variety of climatic, geological, hydrological, topographical, and dendrochronological data composites (Palmer Drought Severity Index (PDSI)). We analyze land-use and settlement capacity and vulnerability to estimate the socio-cultural transformation processes at Basel (Switzerland) during the Late Antiquity and the Early Middle Ages. Our results highlight the potential of the PDSI to predict local river run-off behavior from catchment analyses. The model enables to trace landcover as well as socio-cultural response to climatic variability and subsequent adaptation to trends in environmental vulnerability. This approach further helps to understand population dynamics in the periphery of the Roman administrative boundaries and to revise traditional archaeological narratives of large-scale population replacements during the so-called Migration Period.