bluuebunny/crossref_metadata_2025 huggingface dataset:
Latin American immigration and refugee policies: a critical literature review
Authors: Fernández-Rodríguez Nieves , Freier Luisa Feline
Published: March 2024

Against the background of remarkable policy liberalization and the subsequent steep increase of forced displacement in Latin America, the literature on immigration and refugee policy in the region has gained momentum. Although largely overlooked, this literature has the potential to provide a corrective to political migration theory from the Global South. In this article we carry out a systematic, critical review of the regional literature along three thematic axes: legal analyses, normative and explanatory studies. Based on the review of 108 journal articles, we describe the characteristics, main contributions and research gaps of each thematic area. By analyzing legal norms and policy implementation gaps, existing studies on Latin America provide an understanding of migration policy over time and offer important empirical evidence for the advancement of political migration theory, challenging some of the main assumptions attributed to policies in the Global South. However, the lack of engagement with the broader literature and the absence of systematic analyses of its determinants and effects significantly limit the potential of this body of work. We close by making concrete suggestions of how future studies could fill existing gaps both in theoretical and empirical terms, and which methodological approach should be employed.
Inequality in opportunity of access to antenatal care in Cameroon: multilevel modelling, spatial analysis and decomposition methods
Authors: Youmbi Anne Darline , Nono Betrand Fesuh , Akono Christian Zamo
Published: March 2024

In Cameroon, major inequalities exist in women’s access to antenatal care (ANC), yet underlying circumstance drivers remain understudied. Using recently available Demographic and Health Survey data, we conducted multilevel model and spatial analyses to identify circumstance factors driving ANC disparities across the country's diverse regions. Drawing on a novel integration of theoretical frameworks, we evaluated how circumstances like geographic, economic and educational barriers combined to shape inequities. Both Shapley and Fields decomposition techniques apportioned contributors to ongoing inequality. Results from our study provide the first direct comparison of these approaches in Cameroon, finding a strong positive correlation between methods. Our findings show that ANC utilization overall was suboptimal, varying substantially between urban and rural areas. Key circumstance factors which disproportionately constrained disadvantaged groups’ opportunities for care included household wealth, level of education of the woman and spouse, and place of residence. Policy-relevant insights emerge from disentangling multifaceted opportunity gaps. Targeted interventions should address modifiable barriers facing underserved populations to promote more equal maternal health nationwide. Our multidisciplinary analytical approach offers lessons for analysing complex health disparities in diverse low-resource settings.

Graphical abstract
Improving the underwater navigation performance of an IMU with acoustic long baseline calibration
Authors: Wu Paipai , Nie Wenfeng , Liu Yangfan , Xu Tianhe
Published: March 2024

Underwater acoustic Long-Baseline System (LBL) is an important technique for submarine positioning and navigation. However, the high cost of the seafloor equipment and complex construction of a seafloor network restrict the distribution of the LBL within a small area, making an underwater vehicle difficult for long-distance and high-precision acoustic-based or inertial-based navigation. We therefore propose an acoustic LBL-based Inertial Measurement Unit (IMU) calibration algorithm. When the underwater vehicle can receive the acoustic signal from a seafloor beacon, the IMU is precisely calibrated to reduce the cumulative error of Strapdown Inertial Navigation System (SINS). In this way, the IMU is expected to maintain a certain degree of accuracy by relying solely on SINS when the vehicle reaches out the range of the LBL network and cannot receive the acoustic signal. We present the acoustic LBL-based IMU online calibration model and analyze the factors that affect the accuracy of IMU calibration. The results fulfill the expectation that the gyroscope bias and accelerometer bias are the main error sources that affect the divergence of SINS position errors, and the track line of the underwater vehicle directly affects the accuracy of the calibration results. In addition, we deduce that an optimal calibration trajectory needs to consider the effects of the three-dimensional observability and position dilution of precision. In the experiment, we compare the effects of seven calibration trajectories: straight and diamond-shaped with and without the change of depth, and three sets of curves with the change of depth: circular, S-shaped, and figure-eight. Among them, we find that the figure-eight is the optimal trajectory for acoustic LBL-based IMU online calibration. We take the maintenance period during which the accumulated SINS Three Dimensional (3D) position errors are below 1 km to evaluate the calibration performance. The filed experimental results show that for the Micro-electromechanical Systems-grade IMU sensor, the maintenance period for the IMU calibrated with the proposed algorithm can be increased by 121% and 38.9% compared to the IMU without calibration and with the laboratory default parameter calibration, indicating the effectiveness of the proposed calibration algorithm.
CircMCTP2 enhances the progression of bladder cancer by regulating the miR-99a-5p/FZD8 axis
Authors: Liu Yan , Zhang Kexin , Yang Xianxu
Published: March 2024

Background

CircRNAs and miRNAs are involved in the progression of tumor. CircMCTP2 is considered as a novel tumor promoter. However, the exact functions of circMCTP2 in bladder cancer are still unclear. This study was designed to explore the underlying mechanisms of circMCTP2-modulated tumor development in bladder cancer.

Methods

The present study is an original research. The levels of circMCTP2 in a total of 39 bladder cancer specimens and cell lines were determined by RT-qPCR. The expression of FZD8 in T24 and RT-4 cells treated with miR-99a-5p mimics were examined using western blotting. In addition, the proliferative, migrative and invasive abilities of transfected cells were determined by CCK8 and Transwell assays. Furthermore, the apoptosis of transfected cells was evaluated using flow cytometry. Dual luciferase reporter assay was performed to elucidate the relationship between miR-99a-5p and circMCTP2/FZD8.

Results

The levels of circMCTP2 were elevated in bladder cancer samples and cells, and this was related to worse survival rate. Downregulation of circMCTP2 suppressed growth and metastasis of cells, whereas the apoptotic rate of cells was enhanced. The levels of miR-99a-5rp was elevated after the downregulation of circMCTP2. Moreover, reverse correlation between the expression of miR-99a-5p and circMCTP2 was revealed in bladder cancer specimens. Additionally, FZD8 was the putative target of miR-99a-5p and the mimics of miR-99a-5p inhibited the proliferation, migration and invasion of bladder cancer cells via the FZD8/Wnt-b-catenin axis. Moreover, circMCTP2 regulated the growth and metastasis of bladder cancer cells potentially through regulating the miR-99a-5p/FZD8/Wnt-b-catenin axis. In summary, circMCTP2 was considered as an oncogenic factor through regulating the miR-99a-5p/FZD8/Wnt-b-catenin axis.

Conclusions

This novel signaling could regulate the biological behaviours of bladder cancer cells, and these findings highlighted circMCTP2 as a critical target for treating bladder cancer.
The relationship between dental caries, dietary intake and body composition in school-age children
Authors: Özel İrem Çağla , Erbaş Ünverdi Gizem , Serdar Eymirli Pınar , Yabancı Ayhan Nurcan
Published: March 2024

Objective

The aim of this study is to evaluate the relationship between dental caries, food intake, and body composition in school-age children.

Methods

The study was conducted on 210 children, 105 boys and 105 girls, aged 6–12 years, without mental and/or physical disorders. Oral examinations of the children were performed by paediatric dentists and DMFT–DMFS and dmft–dmfs values were recorded. A detailed food frequency questionnaire was applied to determine the consumption frequency of dairy products and sugar‐added foods. Children’s height, waist and hip circumference measurements were taken by the researcher; body weight and body composition were evaluated with a Tanita body analyzer.

Results

The DMFS value of children who consumed white cheese daily is lower than children who did not (p < 0.05). The DMFT and DMFS values were found to be higher in children who consumed sweets, biscuits, and spreadable chocolate daily compared to children who did not (p < 0.05). Body weight and waist circumference are positively correlated with DMFT and negatively correlated with dmft. BMI is positively correlated with DMFT and negatively correlated with dmft (p < 0.05). In binary logistic regression, it was found that maternal education level, frequency of added sugar intake and body fat ratio were predictors of the presence of caries.

Conclusion

In this study, dental caries was associated with food consumption and body mass index. In children, consumption of sugary foods should be reduced and consumption of dairy products should be increased.
Auditory working memory measures in children with hearing impairment: a systematic review
Authors: Chandran Monisha , Neelamegarajan Devi
Published: March 2024

Auditory working memory (AWM) is the process by which information is held in the brain for a brief duration of time until either it is employed to complete a task, deleted after a short period, or transferred to long-term memory. AWM deficits have been noticed even in children with milder hearing impairments. It is essential to incorporate AWM assessment as a part of the standard audiological battery to minimize the detrimental effects of working memory deficits. The present study systematically reviews the articles published between 2011–2021 regarding test tools available to assess AWM in children with hearing impairment and the efficiency of the same. An overview of the auditory working measures such as the forward and backward digit span test; digit span subtests of Wechsler Intelligence Scale for Children-III; non-word repetition; Illinois test of Psycholinguistic Skills-Forward Digit Span; Numbers reversed subtest from Woodcock-Johnson III Tests of Cognitive Abilities; and Word and non-word recall subtests of Working Memory Test Battery-Children; Number recall, and Word order task from Kaufman Assessment Battery for Children II are provided in detail. The present systematic review also provides an overview of the efficiency of the assessment tools by discussing the correlation between the findings obtained in memory tasks with other auditory, verbal, and visual measures. The working memory performance in children with hearing impairment using a hearing aid or cochlear implant has been found to be affected but varies in nature depending on the degree of hearing loss.
Comparison of Normocalcemic vs Hypercalcemic Primary Hyperparathyroidism in a Hypercalciuric Renal Stone Population
Authors: Halimi Caroline , Bor Clemence , Chieze Remi , Saint-Jacques Camille , Périé Sophie , Wagner Isabelle , Talbot Jean-Noel , Montravers Françoise , Letavernier Emmanuel , Buob David , Daudon Michel , Frochot Vincent , Haymann Jean-Philippe
Published: March 2024

Context

Primary hyperparathyroidism (PHPT) is commonly diagnosed in the setting of hypercalcemia, whereas normocalcemic primary hyperparathyroidism (NHPT) may be misdiagnosed.

Objective

Our objective was to compare patients with hypercalcemic hyperparathyroidism (HPHPT) vs patients with NHPT hypercalciuric renal stones.

Methods

We took advantage of a routine calcium load test performed in patients with hypercalciuric renal stones to assess retrospectively among patients with PHPT the prevalence and characteristics of NHPT and HPHPT under a calcium-restricted diet

Results

Among 1671 patients with hypercalciuria, 91 patients had a final diagnosis of PHPT (postload ionized calcium [iCa] > 1.31 mmol/L and parathyroid hormone [PTH] > 30 pg/mL). Prevalence of NHPT is 40% of all PHPT; however, according to total serum calcium, 4/35 NHPT and 7/56 HPHPT cases would have been misclassified in the other group. Eighteen of 35 NHPT and 40/56 HPHPT cases underwent parathyroidectomy. No significant characteristics relating to parathyroid weight, stone composition, or bone remodeling biomarkers were detected between groups. Although iCa is higher in HPHPT in the fasting state and after calcium load, we found no difference for calcium diet, 24-hour calciuria, or calcitriol. Renal calcium excretion postload increased by 303% in NHPT but only 176% in HPHPT (P = .01) likely explained by a lesser PTH decrease (P = .02). However, a strong negative association (P < .0001) detected between pooled preload and postload iCa and PTH only in the NHPT group suggests a persistent efficient PTH-CaSR control within the parathyroid glands in this group.

Conclusion

Our data show the relevance of dynamic tests to unmask NHPT in patients with hypercalciuric renal stones.
40 years of the homeobox: either it is wrong or it is quite interesting
Authors: Scott Matthew P.
Published: March 2024

Many genes that regulate development share a 180 bp DNA sequence, called the homeobox, encoding a 60 amino acid DNA-binding domain ( McGinnis et al., 1984c; Scott and Weiner, 1984). Because the homeobox is long enough to hybridize to related, but different, genes, it has been a powerful tool for discovering developmental regulators. This year is the 40th anniversary of the first homeobox report. Here, I describe work carried out at Indiana University that led to the discovery of the homeobox. The accompanying Perspective from McGinnis and Levine describes the independent discovery made at the Biozentrum in Basel ( McGinnis and Levine, 2024). At the time, the competition was lively but, as we all met each other – and realized that no one cares more about your work than competitors – we fortunately became friends and have enjoyed many years of following and respecting each other's work.
Further Observations on Vegetable Growth
Authors: Hon  , Osborne Sidney Godolphin
Published: March 2024

It may interest the readers of the ‘Journal’ to know that further observation has given me a deeper insight into the structure of the wheat plant in the earliest stage of its growth. I find there is a “circulation” in every one of the long suckers put forth from the roots; it may be seen very plainly under a power of 800. Although I can trace it with ease along the outer edge of each sucker, running from the root towards the blunt point, I cannot trace any current returning towards the root.
Acceptance of team-based learning by students and faculty: A pilot study
Authors: Rehman Rehana , Ahmad Saara , Nasir Syeda Pinar , Ali Rahila
Published: March 2024

Background & Objective: Team-Based Learning (TBL) is an interactive instructional approach characterized by collaborative peer teaching in both large and small group settings. The study aims to assess usefulness of the TBL in enhancing student learning outcomes and engagement in graduate classes.

Methods: This mixed method study was conducted from January 2023 till July 2023 at the Department of Biological & Biomedical Sciences at Aga Khan University, Karachi, Pakistan, a questionnaire was distributed to graduate students in Endocrine and Reproductive course after TBL on ‘Hormonal changes in Pregnancy’. Focus group discussion (FGD) was held with facilitator of this TBL and the students; results of both arms were then triangulated.

Results: All (four) students responded affirmatively regarding guided self-preparation, quality of application exercises, satisfaction in terms of student’s engagement, a positive attitude and self-accountability. Themes identified by FGD of both students and facilitators were ‘Students Engagement in Peer Learning, ‘Conducive Learning Environment’, “Time is Capital in TBL’ and ‘Conceptual learning.’

Conclusion: The pilot study confirmed the utility of TBL by students as well as the facilitators. Students came with prior preparation, got engaged in problem-solving activities and received feedback from peers and the expert facilitators. The conducive environment enhanced their engagement, enabled them to actively apply the content and benefit from guided supervision.

doi: https://doi.org/10.12669/pjms.40.5.8515

How to cite this: Rehman R, Ahmad S, Nasir SP, Ali R. Acceptance of team-based learning by students and faculty: A pilot study. Pak J Med Sci. 2024;40(5):---------. doi: https://doi.org/10.12669/pjms.40.5.8515

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
A Mutual Catastrophe Insurance Framework for Horizontal Collaboration in Prepositioning Strategic Reserves
Authors: Zbib Hani , Balcik Burcu , Rancourt Marie-Ève , Laporte Gilbert
Published: March 2024

Improving Disaster Preparedness Through Mutual Catastrophe Insurance

In “A Mutual Catastrophe Insurance Framework for Horizontal Collaboration in Prepositioning Strategic Reserves,” H. Zbib, B. Balcik, M.-È. Rancourt, and G. Laporte present an innovative approach to collaborative disaster preparedness. The novel framework considers a risk-averse mutual insurer offering multiyear insurance contracts with coverage deductibles and limits to a portfolio of risk-averse policyholders. It is designed to foster horizontal collaboration among policyholders for joint disaster preparedness by effectively integrating operational and financial functions. The problem is modeled as a large-scale nonlinear multistage stochastic program and solved by using an effective Benders decomposition algorithm. The framework is validated with real data from 18 Caribbean countries focusing on hurricane preparedness. Given the predicted impacts of climate change, the proposed multiyear mutual catastrophe insurance framework promises to reshape global disaster preparedness and make a profound societal impact by providing a transparent disaster financing plan to protect vulnerable regions. The study’s findings stress the importance of long-term cooperation, prenegotiation of indemnification policies, and strategic setting of deductibles and limits by taking into account the correlation between policyholders.
Appointment Requests from Multiple Channels: Characterizing Optimal Set of Appointment Days to Offer with Patient Preferences
Authors: Tunçalp Feray , Örmeci Lerzan
Published: March 2024

We consider the appointment scheduling for a physician in a healthcare facility. Patients, of two types differentiated by their revenues and day preferences, contact the facility through either a call center to be scheduled immediately or a website to be scheduled the following morning. The facility aims to maximize the long-run average revenue, while ensuring that a certain service level is satisfied for patients generating lower revenue. The facility has two decisions: offering a set of appointment days and choosing the patient type to prioritize while contacting the website patients. Model 1 is a periodic Markov Decision Process (MDP) model without the service-level constraint. We establish certain structural properties of Model 1, while providing sufficient conditions for the existence of a preferred patient type and for the nonoptimality of the commonly used offer-all policy. We also demonstrate the importance of patient preference in determining the preferred type. Model 2 is the constrained MDP model that accommodates the service-level constraint and has an optimal randomized policy with a special structure. This allows developing an efficient method to identify a well-performing policy. We illustrate the performance of this policy through numerical experiments, for systems with and without no-shows.

Supplemental Material: The online appendix is available at https://doi.org/10.1287/stsy.2022.0029 .
Minimizing Social Desirability in Questionnaires of Non-Cognitive Measurements
Authors: Setiawati Farida Agus , Widyastuti Tria , Fathiyah Kartika Nur , Nabila Tiara Shafa
Published: March 2024

Data obtained through questionnaires sometimes respond to the items presented by social norms, so sometimes they do not suit themselves. High social desirability (SD) in non-cognitive measurements will cause item bias. Several ways are used to reduce item bias, including freeing respondents from not writing their names or being anonymous, explaining to the participants to respond to each statement honestly, as they are or according to themselves, and responding to the questionnaire online or offline. This research aims to prove that several methods can minimize the possibility of item bias SD and academic dishonesty (AD). The research was carried out with an experimental study using a factorial design. There were 309 respondents who were willing to be involved in this research. Data analysis was carried out using multivariate ANOVA. The research results show differences for all variables, Self-Deceptive Enhancement (SDE), Impression Management (IM), and AD in the anonymous group. There are differences in AD in the groups that provide a complete explanation and do not explain, and there is an interaction between the average AD based on the anonymous and explanation group.
Two Cases of Ipsilateral Posterior Hip Dislocation and Shaft Femur Fracture and Management
Authors:   Department of Orthopaedic Surgery, Shri Lal Bahadur Shastri Government Medical College and Hospital, Mandi, Himachal Pradesh, India,, Vatsyan Kuldeep Chand , Salaria Amit Kumar ,   Department of Orthopaedic Surgery, All India Institute of Medical Sciences, Bilaspur, Himachal Pradesh, India., Katoch Punit ,   Department of Orthopaedic Surgery, Shri Lal Bahadur Shastri Government Medical College and Hospital, Mandi, Himachal Pradesh, India,, Negi Virender ,   Department of Orthopaedic Surgery, Shri Lal Bahadur Shastri Government Medical College and Hospital, Mandi, Himachal Pradesh, India,, Gupta Lokesh ,   Department of Orthopaedic Surgery, Shri Lal Bahadur Shastri Government Medical College and Hospital, Mandi, Himachal Pradesh, India,, Kalia Sandeep ,   Department of Orthopaedic Surgery, Shri Lal Bahadur Shastri Government Medical College and Hospital, Mandi, Himachal Pradesh, India,
Published: March 2024

Introduction: The incidence of ipsilateral fracture of the shaft of the femur and dislocation of the hip are extremely rare injuries. However, the incidence of complex fractures is increasing day by day due to an increasing variety of traumatic mechanisms. This type of injury constitutes various diagnostic and treatment difficulties for the surgeon. Such injuries should be managed on an urgent basis for better functional outcomes. Case Report: We hereby describe two such cases: First case hip was reduced using external fixator pins, stabilization of the shaft femur fracture was done with an external fixator and the second case hip was reduced with bone holding clamps and the shaft femur fracture was fixed with interlocking nail. Conclusion: Fixator-assisted closed reductions are the first line of treatment in the management of posterior dislocation hip complicated with ipsilateral femoral shaft fractures. If closed reduction fails, fracture site can be opened and direct forces can be applied to the proximal femur to aid hip reduction with minimum complications. Keywords: Ipsilateral, posterior hip dislocation, shaft femur fracture, close reduction.
A Novel Use of a Schanz Pin–Rectal Foreign Body Extraction: A Case Report
Authors:   Indiana University School of Medicine, Indianapolis, Indiana, United States,, Chang Joshua H , Haag Luke ,   Indiana University School of Medicine, Indianapolis, Indiana, United States,, Mohanty Sanjay ,   [2] Indiana University Health Physicians, Indianapolis, Indiana, United States, [3] Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana, United States,, Natoli Roman M ,   Department of Orthopedic Surgery, Indiana University School of Medicine, Indianapolis, Indiana, United States.
Published: March 2024

Introduction:Retained rectal foreign bodies (RFBs) can be difficult to extract, forcing the surgeon to get creative. This is the first case report utilizing orthopedic drilling and joystick manipulation techniques for foreign body extraction. Case Report: A 63-year-old male presented to the emergency department with a pool ball in his rectum for 2 days. Extraction attempts under anesthesia both transanally and through a low midline laparotomy were unsuccessful due to the patient’s pelvic anatomy. Orthopedic surgery was consulted to see if any manipulation or resection of the pelvis might aid in extraction. Ultimately, a Schanz pin was drilled retrogradely from the rectum into the pool ball and successfully manipulated the pool ball out of the patient. Conclusion: Techniques such as drilling and joystick manipulation are common in orthopedic surgery but rarely used in other surgical fields. This case presented a novel use of a Schanz pin in RFB extraction. Application of orthopedic surgical technique in a colorectal surgery in this case saved the patient from more invasive interventions such as pubic symphysiotomy or ischial tuberosity resection. Keywords: Foreign body, laparotomy, rectum, Schanz pin.
Operative Treatment of a Patient with a Pathological Fracture through a Large Non-ossifying Fibroma: A Case Report
Authors:   Department of Education, The University of Miami Leonard M. Miller School of Medicine, Miami 33136, Florida,, Cai Nathan , Constantinescu David ,   Department of Orthopaedic Surgery, University of Miami Hospital, Miami 33136, Florida., Trapana Justin ,   Department of Orthopaedic Surgery, University of Miami Hospital, Miami 33136, Florida., Black Brian ,   Department of Orthopaedic Surgery, University of Miami Hospital, Miami 33136, Florida.
Published: March 2024

Introduction: Non-ossifying fibroma (NOF) is a common benign fibrogenic bone lesion commonly found in the metaphysis of long bones. While small NOFs are typically asymptomatic and left untreated, large NOFs are often associated with pathologic fractures that can be treated conservatively or operatively. To our knowledge, the NOF presented in this case report is one of the largest reported in the literature. Case Report: We present a case of a 12-year-old Hispanic female who presented to our institution after falling off a horse and landing on her right leg and wrist. Radiographs revealed a right distal femur fracture through an unusually large lytic bone lesion. The patient was treated with curettage, grafting, open reduction, and internal fixation, given the unstable and pathological nature of the fracture. Conclusion: This case substantiates the literature that large fractures through a NOF can be appropriately managed operatively. However, orthopedic surgeons should be aware of the risks of surgery, including infection, when considering operative management of patients who present with large unstable pathologic fractures through a NOF. Keywords: Non-ossifying fibroma, pediatrics, open reduction, and internal fixation.
The democratising capacity of new municipalism: beyond direct democracy in public–common partnerships
Authors: Bianchi Iolanda
Published: March 2024

New municipalism, in its endeavour to democratise urban politics and policy, employs innovative strategies including public–common partnerships, which seek to support citizens in self-managing public goods and services. Proponents of new municipalism claim that these partnerships have a democratising capacity, as self-management is seen as an expression of direct democracy. In this article we examine this democratising capacity. By adopting an abductive methodology, the article analyses a case of a public–common partnership, the Citizen Assets programme promoted by Barcelona en Comú in Barcelona, Spain. The research findings show that the Citizen Assets programme does have a democratising capacity. However, democratisation is not achieved exclusively through self-management, which itself needs to be democratised, but by integrating different modalities of democratisation into the policy process, namely co-production and democratic control. Theorising this integration as a ‘non-appropriable’ form of policy making, the article makes an original contribution to research on democratisation in the context of a specific new municipalism-inspired policy programme.
Reducing noise in polarization-sensitive optical coherence tomography for high-quality local phase retardation imaging
Authors: Chen Guoqiang , Wang Wen’ai , Li Yanqiu
Published: March 2024

Local phase retardation (LPR) is increasingly recognized as a crucial biomarker for assessing disease progression. However, the presence of speckle noise significantly challenges its accuracy and polarization contrast. To address this challenge, we propose a signal-processing strategy aimed at reducing the impact of noise on LPR measurements. In this approach, the LPR is reconstructed by polar decomposition after averaging multiple Mueller matrices from different overlapping sub-spectra. To optimize measurement accuracy, we systematically combined and traversed different sub-spectral numbers and bandwidths. By examining the quarter-wave plate and glass slide, high-accuracy phase retardation measurements were successfully verified, and the maximum polarization contrast was improved by 23%. Moreover, experimental results from multi-tissue imaging vividly illustrate that the equivalent number of looks (ENL) and polarization contrast were improved by 18% and 19%, respectively. This outcome indicates that our proposed strategy can effectively reduce the noise spikes, enhancing tissue discrimination capabilities.
Optical system design of a femi-class ultra-high-resolution spectrometer based on the quaternary dispersion of a middle echelon grating
Authors: Xue Qingsheng , Song Junhong , Lu Fengqin , Ma Jun , Cao Diansheng
Published: March 2024

In order to meet the needs of the femi-ultra-high spectral resolution test, an optical system of the femi-ultra-high spectral resolution spectrometer in the spectral range of 190–800 nm is designed based on the quaternary dispersion of the middle echelon grating under the condition that the volume and weight of the spectrometer do not increase sharply. After the optimization design, the spectral resolution can reach 51.149 fm in the full field of view of 0.5 mm; at the wavelength of 191 nm, the spectral resolution in the whole spectral range is better than 150 fm, and the maximum distortion of the system is 0.2288%, which can provide a feasible reference for the subsequent design of the spectrometer optical system to realize the simultaneous detection of a wide band and high spectral resolution.
Influence of signal-to-noise ratio on DoLP and AoP measurements during reflectance-mode division-of-focal plane Stokes polarimetry of biological tissues
Authors: Iannucci Leanne E. , Gruev Viktor , Lake Spencer P.
Published: March 2024

Stokes polarimeter based endoscopes are emerging as an area of technology where polarization imaging can greatly impact clinical care by improving diagnostic tools without the use of exogenous contrast. Image acquisition in minimally invasive surgical settings is often beset by inherently limited illumination. A comprehensive analysis of how signal-to-noise (SNR) propagates through Stokes polarimetric outcomes such as degree of linear polarization (DoLP) and angle of polarization (AoP) in low light is important for future interpretation of data acquired in low-light conditions. A previously developed theoretical model of quantitative polarized light imaging (QPLI) analysis described SNR as a function of both incident light intensity and DoLP. When polarized light interacts with biological tissues, the resultant DoLP of exiting light is dependent on the underlying tissue microstructure. Therefore, in this study we explore how low light impacts SNR of QPLI outcomes of DoLP and AoP differently in tissue phantoms of varying microstructures. Data are compared to theoretical solutions of SNR of DoLP and AoP. Tissues were additionally loaded to varying magnitudes of strain to investigate how variable SNR affects the ability to discern dynamic realignment in biological tissues. We observed a high degree of congruency between experimental and theoretical data, with SNR depending on both light intensity and DoLP. Additionally, we found that AoP may have a greater resilience to noise overall than DoLP and, as such, may be particularly useful in conditions where light is inherently limited.
Multilayer Kirkpatrick-Baez focusing mirrors with phase compensation for sub-20 nm focusing at the hard X-ray nanoprobe beamline of SSRF
Authors: Jiang Hui , Xie Jianan , He Yan , Jiang Zhisen , Liang Dongxu , Yu Huaina , Li Aiguo
Published: March 2024

The hard X-ray nanoprobe beamline is the first beamline to take advantage of the full coherent beam to attain the nanoscale focusing at the Shanghai Synchrotron Radiation Facility (SSRF). Here we introduce the beamline and specially go over the features of the multilayer Kirkpatrick-Baez focusing system and its supporting phase compensator system. The performance and stability of the phase compensator are also put to the test. By using the speckle scanning metrology, the wavefront of a focused beam was characterized and intensity distribution near the focus was reconstructed. The focusing performance was greatly enhanced by two phase compensations based on a global optimization technique, and a two-dimensional focal spot of 26 nm × 17 nm was achieved and maintained with good stability.
Isolation of phase edges using off-axis q-plate filters
Authors: Zangpo Jigme , Kobayashi Hirokazu
Published: March 2024

Edge-enhanced microscopes with a q-plate have attracted more attention to enhance the edges of phase-amplitude objects in biological samples due to their capacity for all-directional edge enhancement, while differential interference-contrast microscopy enhances edges in only one-direction. However, the edge-enhanced microscopes cannot distinguish the edges of phase and amplitude objects, as both edges are equally enhanced. This study introduces a novel method for isolating the edge of a phase object from an amplitude object using an off-axis q-plate filter in a 4f system. Herein, we combined off-axis q-plates with four different displacements to isolate the phase object edge from the amplitude object. To demonstrate the proposed method, we conducted experiments using two distinct samples. The first sample comprised a phase test target surrounded by an aperture, and the second sample involved an overlap between the phase test target and a white hair with non-zero transmittance. In the samples, the isolated phase object edge is in good agreement with the theoretical expectations, and the amplitude object edge was reduced by approximately 93%. The proposed method is a novel and effective approach for isolating the edge of a phase object from an amplitude object and can be useful in various biological imaging applications.
Energy-efficient dispersion compensation for digital micromirror device
Authors: Liu Linxian , Zhang Yingxuan , Chen Jiayin , He Qiaozhi , Shen Yang , Qu Yuan , Yang Jiamiao
Published: March 2024

Due to the wave nature of light, the diffraction pattern generated by an optical device is sensitive to the shift of wavelength. This fact significantly compromises the digital micromirror device (DMD) in applications, such as full-color holographic display and multi-color fluorescence microscopy. The existing dispersion compensation techniques for DMD involve adding diffractive elements, which causes a large amount of waste of optical energy. Here, we propose an energy-efficient dispersion compensation method, based on a dispersive prism, for DMD. This method simulates the diffraction pattern of the optical fields reflected from the DMD with an angular spectrum model. According to the simulation, a prism and a set of optical components are introduced to compensate for the angular dispersion of DMD-modulated optical fields. In the experiment, our method reduced the angular dispersion, between the 532 nm and 660 nm light beams, by a factor of ∼8.5.
Fabrication of elliptical-silica microfiber for ultrasound detection
Authors: Yang Haokun , Tatel Gerard , Wang Yuan , Chen Liang , Bao Xiaoyi
Published: March 2024

Elliptical shape microfiber enables many higher order modes compared with a circular microfiber. The small difference in the optical path length among many modes enabled multi-resonance peaks with high contrast in Mach–Zehnder (MZI) interferometers, which allows a large dynamic range and minimum detection sensitivity for broadband ultrasound sensing. In this paper, we present the design and fabrication of an ultra-compact elliptical-silica microfiber utilizing off-axis flame-drawing for ultrasound detection. The narrow transmission peak showed high contrast for ultrasensitive ultrasound wave detection. With a major-axis diameter of 6.25 µm, the elliptical-silica microfiber sensor exhibits a broadband ultrasound frequency response spanning from 20 kHz to 38.5 MHz. Furthermore, it achieves a signal-to-noise ratio (SNR) of up to 80 dB at 1 MHz, which is the resonance frequency of the microfiber and the linear response under driving voltages of 3–10 V for the PZT ultrasound generator. This low-cost microfiber sensor offers exceptional sensitivity across a broad ultrasonic bandwidth response, making it an ideal choice for nondestructive testing (NDT) and medical imaging applications. Its compact size and immunity to electric and magnetic fields further enhance its utility in various environments.
Heat treatment and fiber drawing effect on the matrix structure and fluorescence lifetime of Er- and Tm-doped silica optical fibers
Authors: Vařák Petr , Kamrádek Michal , Aubrecht Jan , Podrazký Ondřej , Mrázek Jan , Bartoň Ivo , Michalcová Alena , Franczyk Marcin , Buczyński Ryszard , Kašík Ivan , Peterka Pavel , Honzátko Pavel
Published: March 2024

We investigate the influence of the optical fiber fabrication process
on the fluorescence lifetime of Er3+ and
Tm3+ ions. Optical fiber preforms were prepared
using the MCVD method combined with Al2O3
nanoparticle doping. The preforms were subjected to various
fabrication processes, such as preform elongation, fiber drawing, and
heat treatment. The matrix structure of the preforms and fibers was
studied by XRD and TEM. The fluorescence lifetime was measured. The
fabrication processes caused the dissolution of the doped
Al2O3 nanoparticles and a significant decrease
of fluorescence lifetime of Tm3+ ions, from 875
µs in the preform down to 610 µs in the fiber, whereas
no significant effect was observed for Er3+ ions,
with fluorescence lifetime in the 9.6–10.2 ms range.
Ultrasensitive refractive index sensing of optical microfiber couplers coated with Ti3C2 MXene
Authors: Peng Rui , Zhou Wenchao , Wu Yihui , Song Zeyuan , Yu Haiyang
Published: March 2024

Two-dimensional (2D) MXene has recently been found to play a significant role in constructing biosensing platforms due to its excellent biocompatibility, large specific surface area, and broad optical absorption. In this article, an ultra-sensitive refractive index (RI) sensor based on an optical microfiber coupler (OMC) coated with Ti3C2 MXene is proposed and experimentally demonstrated. Numerical results reveal that surface modification of MXene enhances the RI sensitivity of OMC and creates a new artificial dispersion turning point (ADTP). The OMC with a dispersion turning point (DTP) at 1300 nm is fabricated using a hybrid fusion elongation-wet etching method. It has a waist width of approximately 2.46 µm. We experimentally achieved the RI sensitivity of 9.1 × 104 ± 0.42 × 104 nm/RIU using the OMC. MXene improves the sensitivity of the OMC because Ti3C2 MXene can change the effective refractive index (ERI) for both the even and odd modes, leading to the interference dips shifting closer to the DTP. The experimental results demonstrate that the RI sensitivity of the OMC coated with Ti3C2 MXene can reach -1.7 × 105 ± 0.2 × 105 nm/RIU, which shows a ∼87% sensitivity boost compared with bare OMC. The proposed sensor is expected to be used for high-sensitivity biochemical molecule detection.
Micro-optics fabrication using blurred tomography
Authors: Webber Daniel , Zhang Yujie , Sampson Kathleen L. , Picard Michel , Lacelle Thomas , Paquet Chantal , Boisvert Jonathan , Orth Antony
Published: March 2024

We demonstrate the fabrication of millimeter-sized optical components
using tomographic volumetric additive manufacturing (VAM). By
purposely blurring the writing beams through the use of a large
etendue source, the layer-like artifacts called striations are
eliminated enabling the rapid and direct fabrication of smooth
surfaces. We call this method blurred tomography and demonstrate its
capability by printing a plano–convex optical lens with
comparable imaging performance to that of a commercially available
glass lens. Furthermore, due to the intrinsic freeform design nature
of VAM, we demonstrate the double-sided fabrication of a biconvex
microlens array, and for the first time demonstrate overprinting of a
lens onto an optical fiber using this printing modality. This approach
to VAM will pave the way for low-cost, rapid prototyping of freeform
optical components.
Highly efficient fiber to Si waveguide free-form coupler for foundry-scale silicon photonics
Authors: Ranno Luigi , Sia Jia Xu Brian , Popescu Cosmin , Weninger Drew , Serna Samuel , Yu Shaoliang , Kimerling Lionel C. , Agarwal Anuradha , Gu Tian , Hu Juejun
Published: March 2024

As silicon photonics transitions from research to commercial deployment, packaging solutions that efficiently couple light into highly compact and functional sub-micrometer silicon waveguides are imperative but remain challenging. The 220 nm silicon-on-insulator (SOI) platform, poised to enable large-scale integration, is the most widely adopted by foundries, resulting in established fabrication processes and extensive photonic component libraries. The development of a highly efficient, scalable, and broadband coupling scheme for this platform is therefore of paramount importance. Leveraging two-photon polymerization (TPP) and a deterministic free-form micro-optics design methodology based on the Fermat’s principle, this work demonstrates an ultra-efficient and broadband 3-D coupler interface between standard SMF-28 single-mode fibers and silicon waveguides on the 220 nm SOI platform. The coupler achieves a low coupling loss of 0.8 dB for the fundamental TE mode, along with 1 dB bandwidth exceeding 180 nm. The broadband operation enables diverse bandwidth-driven applications ranging from communications to spectroscopy. Furthermore, the 3-D free-form coupler also enables large tolerance to fiber misalignments and manufacturing variability, thereby relaxing packaging requirements toward cost reduction capitalizing on standard electronic packaging process flows.
Genome biology and evolution of mating-type loci in four cereal rust fungi
Authors: Luo Zhenyan , McTaggart Alistair , Schwessinger Benjamin
Published: March 2024

Permanent heterozygous loci, such as sex- or mating-compatibility regions, often display suppression of recombination and signals of genomic degeneration. In Basidiomycota, two distinct loci confer mating compatibility. These loci encode homeodomain (HD) transcription factors and pheromone receptor (Pra)-ligand allele pairs. To date, an analysis of genome level mating-type (MAT) loci is lacking for obligate biotrophic basidiomycetes in the Pucciniales, an order containing serious agricultural plant pathogens. Here, we focus on four species of Puccinia that infect oat and wheat, including P. coronata f. sp. avenae, P. graminis f. sp. tritici, P. triticina and P. striiformis f. sp. tritici. MAT loci are located on two separate chromosomes supporting previous hypotheses of a tetrapolar mating compatibility system in the Pucciniales. The HD genes are multiallelic in all four species while the PR locus appears biallelic, except for P. graminis f. sp. tritici, which potentially has multiple alleles. HD loci are largely conserved in their macrosynteny, both within and between species, without strong signals of recombination suppression. Regions proximal to the PR locus, however, displayed signs of recombination suppression and genomic degeneration in the three species with a biallelic PR locus. Our observations support a link between recombination suppression, genomic degeneration, and allele diversity of MAT loci that is consistent with recent mathematical modelling and simulations. Finally, we confirm that MAT genes are expressed during the asexual infection cycle, and we propose that this may support regulating nuclear maintenance and pairing during infection and spore formation. Our study provides insights into the evolution of MAT loci of key pathogenic Puccinia species. Understanding mating compatibility can help predict possible combinations of nuclear pairs, generated by sexual reproduction or somatic recombination, and the potential evolution of new virulent isolates of these important plant pathogens.
Developing interconnectedness is critical in retaining rural general practitioners: A qualitative thematic analysis of recently recruited general practitioners to South East New South Wales, Australia
Authors: Burgis-Kasthala Sarath , Bain-Donohue Suzanne , Tailby Ellen , Stonestreet Kathryn , Moore Malcolm
Published: March 2024

Australia, in common with many countries globally, has a shortage of doctors working rurally. Whilst strategies and current research focus on recruitment, attrition from rural practice is a significant determinant of such shortages. Understanding doctors’ decisions to stay or leave, once recruited, may provide further insights on how to address this rural differential. This study comprises a qualitative study of 21 recently recruited nationally-trained doctors and international medical graduates to a rural area of New South Wales, Australia. Interviews focused on their experiences prior to and within rural practice, and how these influenced their future career intentions. We used reflexive thematic analysis with each interview coded by two researchers to build an explanatory framework. Our findings comprise five themes which applied differentially to nationally-trained doctors and international medical graduates: connectedness across professional, personal and geographic domains, how multi-faceted connectedness was, and dissonance between participants’ expectations and experiences. Amongst nationally-trained doctors, connectedness stemmed from prior rural experiences which engendered expectations founded upon their ability to develop community-level relationships. Experiences were mixed; some described difficulties maintaining a boundary between their personal and professional lives, which encroached upon their ability to embed within the community. International medical graduates’ expectations were cultivated by their pre-conceptions of Australian postgraduate training but they lamented a lack of professional opportunities once in practice. Moreover, they described a lack of professional relationships with local, nationally-trained, doctors that could help them embed into rural practice. This study highlighted that when connectedness occurs across professional, geographic and personal domains doctors are more likely to continue rural practice, whilst illustrating how the importance of each domain may differ amongst different cadres of doctor. Supporting such cadres develop supportive interrelationships may be a low hanging fruit to maximise retention.