bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of germline progenitors in larval queen honeybee ovaries
Authors: Cullen Georgia , Delargy Erin , Dearden Peter K.
Published: September 2024

Honeybees (Apis mellifera) are a keystone species for managed pollination and the production of hive products. Eusociality in honeybees leads to much of the reproduction in a hive driven by the queen. Queen bees have two large active ovaries that can produce large numbers of eggs if conditions are appropriate. These ovaries are also active throughout the long lives of these insects, up to 5 years in some cases. Recent studies have indicated that the germline precursors of the adult honeybee queen ovary are organized into 8-cell clusters, joined together by a polyfusome; a cytoplasmic bridge. To understand the origin of these clusters, and trace the development of the honeybee queen ovary, we examined the cell types and regionalization of the developing larval and pupal queen ovaries. We used established (nanos and castor), and novel (odd skipped) gene expression markers to determine regions of the developing ovary. Primordial germline cells develop in the honeybee embryo and are organized into ovary structures before the embryo hatches. The ovary is regionalized by larval stage 3 into terminal filaments and germaria. At this stage, clusters of germline cells in the germaria are joined by fusomes and are dividing synchronously. The origin of the 8-cell clusters in the adult germarium is therefore during larval stages. On emergence, the queen ovary has terminal filaments and germaria but has not yet developed any vitellaria, which are produced after the queen embarks on a nuptial flight. The lack of germaria, and the storing of germline progenitors as clusters, may be adaptions for queen bees to endure the metabolic demands of a nuptial flight, as well as rapidly lay large numbers of eggs to establish a hive.
Modeling the roles of cohesotaxis, cell-intercalation, and tissue geometry in collective cell migration of Xenopus mesendoderm
Authors: Comlekoglu Tien , Dzamba Bette J. , Pacheco Gustavo G. , Shook David R. , Sego T. J. , Glazier James A. , Peirce Shayn M. , DeSimone Douglas W.
Published: September 2024

Collectively migrating Xenopus mesendoderm cells are arranged into leader and follower rows with distinct adhesive properties and protrusive behaviors. In vivo, leading row mesendoderm cells extend polarized protrusions and migrate along a fibronectin matrix assembled by blastocoel roof cells. Traction stresses generated at the leading row result in the pulling forward of attached follower row cells. Mesendoderm explants removed from embryos provide an experimentally tractable system for characterizing collective cell movements and behaviors, yet the cellular mechanisms responsible for this mode of migration remain elusive. We introduce a novel agent-based computational model of migrating mesendoderm in the Cellular-Potts computational framework to investigate the respective contributions of multiple parameters specific to the behaviors of leader and follower row cells. Sensitivity analyses identify cohesotaxis, tissue geometry, and cell intercalation as key parameters affecting the migration velocity of collectively migrating cells. The model predicts that cohesotaxis and tissue geometry in combination promote cooperative migration of leader cells resulting in increased migration velocity of the collective. Radial intercalation of cells towards the substrate is an additional mechanism contributing to an increase in migratory speed of the tissue. Model outcomes are validated experimentally using mesendoderm tissue explants.
A prioritization tool for cilia-associated genes and their in vivo resources unveils new avenues for ciliopathy research
Authors: Van Sciver Robert E. , Caspary Tamara
Published: September 2024

Defects in ciliary signaling or mutations in proteins that localize to primary cilia lead to a class of human diseases known as ciliopathies. Approximately 10% of mammalian genes encode cilia-associated proteins, and a major gap in the cilia research field is knowing which genes to prioritize to study and finding the in vivo vertebrate mutant alleles and reagents available for their study. Here, we present a unified resource listing the cilia-associated human genes cross referenced to available mouse and zebrafish mutant alleles, and their associated phenotypes, as well as expression data in the kidney and functional data for vertebrate Hedgehog signaling. This resource empowers researchers to easily sort and filter genes based on their own expertise and priorities, cross reference with newly generated -omics datasets, and quickly find in vivo resources and phenotypes associated with a gene of interest.
Human walking biomechanics on sand substrates of varying foot sinking depth
Authors: Grant Barbara F. , Charles James P. , D'Août Kristiaan , Falkingham Peter L. , Bates Karl T.
Published: September 2024

Our current understanding of human gait is mostly based on studies using hard, level surfaces in a laboratory environment. However, humans navigate a wide range of different substrates every day, which incur varied demands on stability and efficiency. Several studies have shown that when walking on natural compliant substrates there is an increase in energy expenditure. However, these studies report variable changes to other aspects of gait such as muscle activity. Discrepancies between studies exist even within substrate types (e.g. sand), which suggests that relatively ‘fine-scale’ differences in substrate properties exert quantifiable influences on gait mechanics. In this study, we compared human walking mechanics on a range of sand substrates that vary in overall foot sinking depth. We demonstrated that variation in the overall sinking depth in sand was associated with statistically significant changes in joint angles and spatiotemporal variables in human walking but exerted relatively little influence on pendular energy recovery and muscle activations. Significant correlated changes between gait metrics were frequently recovered, suggesting a degree of coupled or mechanistic interaction in their variation within and across substrates. However, only walking speed (and its associated spatiotemporal variables) correlated frequently with absolute foot sinkage depth within individual sand substrates, but not across them. This suggests that a causative relationship between walking speed and foot sinkage depth within individual sand substates is not coupled with systematic changes in joint kinematics and muscle activity in the same way as is observed across sand substrates.
On the rate-limiting dynamics of force development in muscle
Authors: van der Zee Tim J. , Wong Jeremy D. , Kuo Arthur D.
Published: September 2024

Skeletal muscles produce forces relatively slowly compared with the action potentials that excite them. The dynamics of force production are governed by multiple processes, such as calcium activation, cycling of cross-bridges between myofilaments, and contraction against elastic tissues and the body. These processes have been included piecemeal in some muscle models, but not integrated to reveal which are the most rate limiting. We therefore examined their integrative contributions to force development in two conventional types of muscle models: Hill-type and cross-bridge. We found that no combination of these processes can self-consistently reproduce classic data such as twitch and tetanus. Rather, additional dynamics are needed following calcium activation and facilitating cross-bridge cycling, such as for cooperative myofilament interaction and reconfiguration. We provisionally lump such processes into a simple first-order model of ‘force facilitation dynamics’ that integrate into a cross-bridge-type muscle model. The proposed model self-consistently reproduces force development for a range of excitations including twitch and tetanus and electromyography-to-force curves. The model's step response reveals relatively small timing contributions of calcium activation (3%), cross-bridge cycling (3%) and contraction (27%) to overall force development of human quadriceps, with the remainder (67%) explained by force facilitation. The same set of model parameters predicts the change in force magnitude (gain) and timing (phase delay) as a function of excitatory firing rate, or as a function of cyclic contraction frequency. Although experiments are necessary to reveal the dynamics of muscle, integrative models are useful for identifying the main rate-limiting processes.
Lung mechanics in juvenile and adult Chelonoidis carbonarius
Authors: Oliveira Paulo Roberto Custodio de , Trevizan-Baú Pedro , Souza Ray Brasil Bueno de , Klein Wilfried
Published: September 2024

Testudines possess a rigid shell that influences the mechanics of the respiratory system. We studied respiratory mechanics in the terrestrial red-footed tortoise Chelonoidis carbonarius (Cryptodira), comparing juvenile individuals with a less ossified and more flexible carapace with adults with a well-ossified rigid shell. Combined with these ontogenetic differences, we analyzed respiratory system mechanics with animals in a supine and a prone position, as well as in the isolated lungs, to evaluate the impact of the viscera on breathing mechanics. To do so, we used established protocols to measure pulmonary volume (i.e. resting, VLr; and maximum, VLm), static (Cstat) and dynamic (Cdyn) compliance, and the work of breathing (W). We observed that isolated lungs displayed increased VLr, VLm, Cstat and Cdyn and decreased W. Additionally, pulmonary volume, compliance and W were affected by evaluated position, such as a smaller VLr in a supine position. Cdyn and W showed a volume dependency while frequency had less influence on these variables. At similar levels of ventilation, juveniles showed a lower W than adults when standardized by body mass, but similar W when standardized by VLr. Clear ontogenetic changes could be observed in breathing mechanics between juvenile and adult C. carbonarius. While these differences might largely be explained by variation in shell ossification, other explanations such as differences in visceral proportions or developmental degree of the post-pulmonary septum should also be taken into account.
The effect of temperature and breathing pattern on the surface activity of ground squirrel pulmonary surfactant
Authors: Tejura Akash , Sun Mengxi , McCaig Lynda , Staples James , Veldhuizen Ruud
Published: September 2024

This study investigates how hibernation affects the surface activity of pulmonary surfactant with respect to temperature and breathing pattern. Surfactant was isolated from a hibernating species, the 13-lined ground squirrel, and a homeotherm, the rabbit, and analysed for biophysical properties on a constrained sessile drop surfactometer. The results showed that surfactant from ground squirrels reduced surface tension better at low temperatures, including when mimicking episodic breathing, as compared with rabbit surfactant. In addition, low temperature adaptation was also observed using only the hydrophobic components of surfactant from ground squirrels. Overall, the data support the conclusion that ground squirrel surfactant has adapted to maintain surface activity during low temperature episodic breathing patterns, and that temperature adaptation is maintained with the hydrophobic components of the surfactant.
Results of a Prospective Randomized Multicenter Study Comparing Indocyanine Green (ICG) Fluorescence Combined with a Standard Tracer Versus ICG Alone for Sentinel Lymph Node Biopsy in Early Breast Cancer: The INFLUENCE Trial
Authors: Pitsinis Vassilis , Kanitkar Rahul , Vinci Alessio , Choong Wen Ling , Benson John
Published: September 2024

Background

For clinically node-negative early breast cancer patients, sentinel lymph node biopsy (SLNB) using dual localization with blue dye and radioisotope (RI) is currently standard of care. Documented disadvantages with these tracers have prompted exploration of alternative agents such as fluorescent indocyanine green (ICG), which demonstrates high detection rates combined with other tracers. Results of a randomized study evaluating ICG as a single tracer for SLN identification are presented.

Methods

Overall, 100 patients with unilateral, clinically node-negative, biopsy-proven invasive breast cancer (≤5 cm) scheduled for SLNB were recruited in two separate randomized cohorts, with 50 patients receiving ICG alone. Cohort 1 received ICG alone (n = 25) or combined with RI [Technetium99] (n = 25), while Cohort 2 received ICG alone (n = 25) or combined with blue dye (n = 25). The primary outcome was sensitivity for SLN identification.

Results

Among evaluable patients (n = 97), the overall SLN identification rate was 96.9% (ICG alone = 97.9%; ICG + RI = 100%; ICG + blue dye = 92%). Node positivity rates were 14.9% for ICG alone, 16% for ICG combined with RI, and 20% for ICG combined with blue dye. There were no significant differences (p < 0.05) in performance parameters, with ICG alone being non-inferior to tracer combinations for procedural node positivity rates when adjusted for specific factors.

Conclusion

These results support potential use of ICG as a sole tracer agent for routine SLNB, thereby avoiding disadvantages of RI and/or blue dye. The latter can be safely withheld as a co-tracer without compromising detection of positive nodes in primary surgical patients.
Testing for Screening using vocational skills: The case of upper secondary general and vocational education in Greece
Authors: Velaora Argyro , Chanis Stefanos , Tsamadias Constantinos
Published: September 2024

Abstract
The paper examines if upper secondary education acts as a filter in the private sector of the Greek labor market and tests both the «strong» version and the «weak» version of the screening hypothesis. The paper uses the method of Mincerian earnings function with an interaction term on years of education or training and experience in labor market. The data has been collected through primary research and include employees who are graduates of upper secondary, general and vocational education and lower secondary education (control group) and they are working in the private sector. Applying the method reveals that for the employees in the private sector (Total data) who are holders of an upper secondary education diploma (general and vocational) and lower secondary education diploma the criteria of the weak version are met. Particularly, per gender and in above educational cases, the results are statistically significant for females and show that is valid the weak version. As concerns the males, the results are not statistically significant.
Keywords: Upper secondary education, general and vocational, human capital, screening hypothesis
What we know and what should we know about the future of blockchain in finance
Authors: Singh Shikta , Jaiswal Rachana , Gupta Shashank , Kumar Chinmoy
Published: September 2024

Background In response to the transformative impact of blockchain technology on economic and financial landscapes, there is a critical need for a review study that analyses the knowledge landscape from diverse perspectives. Methods This research VOSviewer, and Bibliometrix to undertake a bibliometric analysis of the expanding literature related to blockchain technology within the financial sector. Through a examination of 500 published articles, the study identifies insightful trends, patterns, and emerging domains on a global scale. Results The findings highlight the advancing trajectory of blockchain research in finance, with a notable concentration of studies originating from the United States and China, both in terms of total publications and citations. Key thematic clusters identified include “smart contracts,” “financial institutions,” “initial coin offerings,” and “big data analytics.” Intersections with financial risk management, digital transformation, and the integration of big data analytics with artificial intelligence and machine learning are particularly noteworthy, marking focal points of exploration. Conclusions While affirming the potential of blockchain, the analysis also sheds light on persistent impediments hindering its widespread adoption and utilization. This study not only contributes to the current understanding of blockchain in finance but also serves as a valuable resource for future researchers. It guides systematic reviews by pinpointing prominent journals and influential authors within the dynamic field of blockchain finance, thereby fostering a deeper understanding and facilitating further exploration in this evolving field.
Effectiveness of Providing Cash Incentives and Training To Community Health Workers on Active Case Finding for Tuberculosis In Nigeria: A Cluster-Randomized Control Trial
Authors: Akwaowo Christie , Umoh Victor , Umoh Idongesit , Usoroh Eno , Motilewa Olugbemi , Ekpin Victory , Adeboye Stella , Antia Etop
Published: September 2024

Background Case detection for Tuberculosis remains low in high-burden communities. Community Health Workers (CHWs) are the first point of contact for many rural Nigerians and have been useful in active case finding. This study assessed the effectiveness of cash incentives and training on tuberculosis case detection by CHWs in six Local Government Areas in Nigeria. Materials and Methods A cluster randomized control trial with three arms was conducted. Arm A received cash incentives and training, Arm B received only training, and the control arm (C) received neither. CHWs already working in the communities participated. TB case notification and number of community outreaches held were used to assess intervention effects. Data were analyzed using STATA (v.13) and GraphPad Prism (v.8). Effect sizes were calculated using odds ratios and 95% confidence intervals. Associations were tested using Chi-square (χ²) tests, with significance set at P=0.05. Results Arm A had a 14.4% increase in case notification, Arm B showed a 7.4% increase, and the control arm showed a 39.7% increase from the previous year. Arms A and B had lower odds of TB case notification post-intervention, compared to the control (OR = 0.819 and 0.769, respectively), with no significant difference between them. Arm A also saw a 144.8% increase in community outreaches, compared to 46.7% in Arm B and 22.7% in Control Arm C. Arms A and B had higher odds of carrying out community outreaches post-intervention compared to the control (OR = 1.995 and 1.195, respectively), but no significant differences were found between the groups regarding community outreach. Conclusion While the interventions resulted in an increased number of community outreaches compared to the control, case notification improved more in the control arm than in the intervention arms. Nevertheless, the findings highlight the potential of combining cash incentives with training to improve TB control efforts at the community level. Further exploration of the implementation process may shed light on the observed outcomes and guide future intervention strategies.
Psychosocial Maturity, Depression and Self-esteem in Undergraduate Students
Authors: Yeo Jeong Hee , Hyun Mi Yeul , Lee Eun Joo , Park Eun Ok , Kim Jeong Hee , Song Hyo Jeong
Published: September 2024

Purpose: This study aimed to investigate the extent of relationships between the psychosocial maturity, depression and self-esteem of undergraduate students. Methods: Data were drawn from a convenient sample of students(N=409). For the survey tool, it was used that the Psycho-social Maturity Scale, Beck Depression Inventory(BDI-II) and Self Esteem Scale.Results: Emotional security (psycho-social maturity sub scale) was differentiated by general characteristics : gender, living standard, mark of last term, smoking, current drinker and regular exercise. Social cognitive competence (psycho-social maturity sub scale) was differentiated by general characteristics : gender, grade, smoking and regular exercise. Social relationship (psycho-social maturity sub scale) was differentiated by general characteristics : gender, boy(girl) friends, living standard, smoking, current drinker and regular exercise. Positive thoughts (psycho-social maturity sub scale) was differentiated by general characteristics : gender, smoking and regular exercise. Depression was differentiated by living standard. Self-esteem was differentiated by schoolwork. Significant negative correlation was found between self esteem and depression.Significant positive correlation was found between self esteem and emotional security, social relationship and positive thoughts. Also, significant positive correlation was found between depression and social cognitive competence.
Grounded Theory Methodology - Strauss’ version vs Glaserian version -
Authors: Choe Kwisoon
Published: September 2024

Background: Anselm Strauss and Barney Glaser, two sociologists developed the grounded theory methodology in the 1960's. However, now there are some differences between Strauss' methodology and Glaser's methodology.Purpose: This study was to describe the differences between Strauss* version and Glaser's version in grounded theory methodology. Methods: This study used a comparative analysis through literatures review on grounded theory methodological issues in order to see what similarities and differences are between Strauss 1 version and Glaserian version. Results: Their some methodological differences were summarized into four parts: a) selecting of the research problem, b) interview questions, c) literatures review, and d) analysis process. Conclusion: As researchers apply the grounded theory methodology to his/her study, they have to consider which approaches they select: Strauss* version, Glaserian version, or a compromised version.
Health Promoting Behavior of the Family Care-giver in the Patients with Chronic Mental Disorders
Authors: Han Kuem Sun
Published: September 2024

Purpose: The purpose of this study was to identify the factors influencing health promoting behaviors(HPB) of the family with chronic mental disorders. Methods: Data were collected by questionnaires from 365 family with the patients of chronic mental illness in outpatient clinic of the General Hospital and Government Psychiatric Hospital in Seoul. The data were analyzed using descriptive statistics, pearson correlation coefficients, and stepwise multiple regression. Results: The score of HPB showed significantly positive correlation with the score of level of FH (r=.46, p=.00), FC (r=,47, p=.00), self efficacy(SE) (r=.37, p=.00), and FR(r=.46, p=,00). The most powerful predictor of HPB was FC (23%). A combination of FC, SE, and FH account for 32 % of the variance in HPB of the family with chronic mental illness. Conclusion: This study suggest that FH, FC, SE, and FR are significantly influencing factors on the HPB of the family with the patients of chronic mental illness.
Modified Apexification Procedures in Immature Necrotic Permanent Teeth: A Case Report
Authors: Sebastian Nikita , Annapoorna BM
Published: September 2024

Immature necrotic permanent teeth with a significant amount of coronal hard tissue loss are treated by apexification procedures. These procedures do not encourage further root maturation, predisposing the teeth to possible root fractures. The modified apexification procedure simulates regenerative endodontic procedures in encouraging root development in terms of increased dentine thickness contributing to improved resistance to fracture, while allowing the canal space to be used for core retention. This case report presents an immature tooth treated by the modified apexification procedure with an 18-month follow-up.

CPD/Clinical Relevance: An alternative therapy in managing immature necrotic permanent teeth is of relevance to clinicians.
‘We want to reset the relationship’
Authors: Roberts Elly , Morgan Stephen
Published: September 2024

Editor of EYE, Elly Roberts, interviewed the early education minister, Stephen Morgan, MP for Portsmouth South, about his plans for the early years sector now that the Labour Party are in power.
Vascular complications of liver abscess: A literature review
Authors: Arya Rahul , Kumar Ramesh , Priyadarshi Rajeev N , Narayan Ruchika , Anand Utpal
Published: September 2024

Extensive vascular network and proximity to the gastrointestinal tract make the liver susceptible to abscess formation. While pyogenic liver abscesses account for the majority of liver abscesses in the Western world, amebic liver abscesses are more prevalent in tropical and developing nations. Most liver abscesses heal without complications. However, various vascular complications can occur in these patients, including compression of the inferior vena cava, thrombosis of the portal vein and/or hepatic veins, hepatic artery pseudoaneurysm, direct rupture into major vessels or the pericardium, and biliovascular fistula. These complications can present significant clinical challenges due to the potential for haemorrhage, ischemia, and systemic embolism, thereby increasing the risk of morbidity and mortality. Mechanical compression, flow stasis, inflammation, endothelial injury, and direct invasion are some of the proposed mechanisms that can cause vascular complications in the setting of a liver abscess. For the diagnosis, thorough assessment, and therapeutic planning of vascular complications, more sophisticated imaging techniques such as multidetector computed tomography angiography or magnetic resonance angiography may be necessary. Although most vascular complications resolve with abscess treatment alone, additional interventions may be required based on the nature, severity, and course of the complications. This article aims to provide a systematic update on the spectrum of vascular complications of liver abscesses, offering insights into their pathogenesis, diagnosis, and management strategies.
Comparing optical combining methods for fiber-bundle-based free-space
optical receivers
Authors: LoPresti Peter , Broyles Joseph
Published: September 2024

Fiber-bundle-based free-space optical receivers have potential to increase the receiver field of view and mitigate turbulence effects on collected power. Combining optical signals from individual fibers into a single data signal remains a challenge. We present a homogenizer-based method for optically combining individual signals and compare this to a lens-based method. A simulation assessed signal combining properties of the homogenizer system. Experiments compared the two methods on the field of view (FOV) and bit-error-rate (BER) versus the signal to noise ratio (SNR) for a range of turbulence levels. The homogenizer-based method increases the FOV by at least three degrees. The BER increased more slowly with increasing turbulence for the homogenizer-based method than for the lens-based design and was lower for all turbulence levels studied. Thus, the homogenizer-based method provides a potentially viable solution for addressing the signal combination problem in fiber-bundle-based receivers.
Mesoscopic axially swept oblique plane microscope for the imaging of freely moving organisms with near-isotropic resolution
Authors: Davis Samuel , Sommernes Jon-Richard , Hambura Sebastian , Riedel Levin , Gil Alejandro , Ikmi Aissam , Ströhl Florian , Prevedel Robert
Published: September 2024

Rapid three-dimensional imaging over extended fields of view (FOVs) is crucial to the study of organism-wide systems and biological processes in vivo. Selective-plane illumination microscopy (SPIM) is a powerful method for high spatio-temporal resolution in toto imaging of such biological specimens. However, typical SPIM implementations preclude conventional sample mounting and have anisotropic imaging performance, in particular when designed for large FOVs over 1 mm diameter. Here, we introduce axial sweeping of the illumination into a non-orthogonal dual-objective oblique plane microscope (OPM) design, thereby enabling the observation of freely moving animals over millimeter-sized FOVs, at close to isotropic, sub-cellular resolution. We apply our mesoscopic axially swept OPM (MASOPM) to image the behavioral dynamics of the sea anemone Nematostella vectensis over 1 × 0.7 × 0.4 mm at 1.7 × 2.6 × 3.7 µm resolution and 0.5 Hz volume rate.
Multimodal segmentation of dynamic subcellular features using quantitative phase imaging and FRET-based sensors [Invited]
Authors: Highland Robert E. , Rancu Albert , Price Hillel , Parker Steven M. , Reynolds Meghan , Hoffman Brenton D. , Wax Adam
Published: September 2024

Understanding cellular responses to mechanical environmental stimuli is important for cellular mechanotransduction studies. While fluorescence microscopy has been used for aiding mechanotransduction research due to its molecular sensitivity, the ability of quantitative phase imaging (QPI) to visualize morphology has yet to be widely applied, perhaps due to its limited specificity. Here, we seek to expand on previous work which combined quantitative phase imaging with a molecularly sensitive Förster resonance energy transfer (FRET) construct by developing additional analysis techniques. This work seeks to characterize the response of individual cells to mechanical stimulus through a novel, to the best of our knowledge, QPI-guided cellular segmentation algorithm. The multimodal imaging instrument and analysis techniques are employed to examine cellular responses to hypo-osmotic stimulus by observing the calcium ion flux using a FRET-based sensor coupled with a mapping of intracellular mass reorganization using QPI. The combined imaging modality enables a discrimination of cell response by localized region, revealing distinct behavior between regions and relative to a control group. Our novel analysis techniques can be used to identify cell expansion and cell region specific responses in both modalities due to the stimulus. With the broad array of FRET sensors under development, the complementary addition of QPI offers new avenues for studying cell responses to a range of environmental stimuli.
Adaptive multi-surrogate model for complex opto-mechanical system alignment
Authors: Wu Songhang , Li Min , Jia Hongbo
Published: September 2024

Owing to the inherent nonlinearity of surrogate models, they have been widely used in the alignment of complex opto-mechanical systems. Finding the most suitable surrogate model for misalignment wavefront errors is challenging. This study proposes an adaptive multi-surrogate model (AMSM) based on the concept of layer-by-layer approximation and adaptive selection and a compensation mechanism to facilitate the combination of the AMSM and non-dominated sorting genetic algorithm II (NSGA-II). For example, alignment simulations of an off-axis three-mirror anastigmatic (TMA) telescope and a catadioptric microscope objective were performed. The results show that the AMSM is well done in terms of approximate accuracy and efficiency. The application of the proposed method in the off-axis TMA telescope leads to 65.2% and 18.7% reductions in the full-field average RMS wavefront error compared with the traditional sensitivity table method (STM) and radial basis function (RBF) network surrogate model, respectively. Similarly, for the catadioptric microscope objective, there is a reduction of 43.5% and 22.4%, respectively. The AMSM will further promote the development of a surrogate model to align more complex and precise opto-mechanical systems.
Measuring the polarized complex forward-scattering amplitudes of single particles in unbounded fluid flow: CAS-v2 protocol
Authors: Moteki Nobuhiro , Adachi Kouji
Published: September 2024

A detailed protocol for measuring the complex forward-scattering amplitude S(0°) of single particles, the Complex Amplitude Sensing version 1 (CAS-v1), has recently been developed and used for characterizing environmental particles. However, interpretations of the S(0°) data need a priori assumptions on the particle’s shape, and applications of the method have mostly been limited to the particles suspended in liquids. Here, we thoroughly upgrade the CAS technique to perform quality-controlled S(0°) measurements at two independent polarizations for particles suspended in gases and liquids. The polarization-resolved S(0°) sensing constrains the particle’s shape and improves the physical interpretability of data. An optical coherence backscattering detection technique enables non-invasive yet precise constraints of the particle’s location in the sensing region, realizing precise S(0°) measurements even for aerosol particles introduced via a gas jet without using a flow microchannel. The CAS-v2 protocol proposed here will be useful as a fast yet detailed particle measurement technique for laboratory and field studies.
Scheme of flash LiDAR employing glass aspherical microlens array with large field of illumination for autonomous vehicles
Authors: Huang Kuo-Yin , Wang Chih-Feng , Shih Dong-Li , Chang Ke-Peng , Chang Yung-Peng , Liu Chun-Nien , Cheng Wood-Hi
Published: September 2024

This study demonstrates a new scheme of flash LiDAR using a glass aspherical microlens array (MLA) to achieve a large field of illumination (FOI) for autonomous vehicles. A wider FOI of up to 100° was obtained. In contrast to a spherical MLA, the FOI is 38.9° which indicates that the proposed aspherical MLA is 2.6 times wider than the spherical MLA. The wider FOI achieved for the glass MLA is due to a novel laser drilling technique that produces conical micro-holes with a high aspect ratio (depth: diameter = 1.8:1), forming elliptical-like aspherical microlenses through wet etching. An FOI estimation model to provide theoretical basis for designing aspherical MLA with wider FOI is presented, which is in good agreement with experimental results. Furthermore, the optical efficiency of 90% for the FOI was calculated. In this study, we have proposed a unique laser drilling technique to produce glass aspherical MLA with wider FOI and higher optical efficiency for flash LiDAR use in autonomous vehicle applications.
Error analysis model-driven workflow for self-calibration stitching testing of X-ray flat surfaces
Authors: Liu Yong , Jian Haopeng , Xue Shuai , Gao Xibo , Hu Zubo , Huang Antong , Dai Yifan
Published: September 2024

Self-calibration stitching test is widely utilized for testing X-ray flat surfaces. Various factors, including environment disturbances, motion errors, misalignments, overlapping ratios, and sub-aperture sizes can affect the accuracy. Previous studies have shown that motion errors can introduce slope errors in the test surface, and higher overlapping ratios can increase the test error. However, these error analyses have not been comprehensive or quantitatively sufficient for practical applications. For X-ray flat surfaces with specific accuracy requirements, the necessary control levels for error sources and the optimal test parameters remain unclear. To this end, an error analysis model-driven workflow for self-calibration stitching testing of X-ray flat surfaces is proposed. This model allows for the systematic evaluation of how different error sources and test parameters affect test accuracy. Further, it can guide the determination of the control levels of error sources and test parameters, moving beyond the reliance on empirical experience as seen in previous studies. A flat X-ray mirror with clear aperture of 250 mm × 30 mm and 0.2 nm (50 nrad) RMS accuracy requirement was utilized to demonstrate the procedures of the workflow. Verification experiments demonstrated that this workflow can serve as a standard model for evaluating test accuracy and guiding test procedures to achieve the desired accuracy in self-calibration stitching of X-ray flat mirrors.
Optically driven ultraviolet-C glowing from an in situ trapping–detrapping approach
Authors: Wang Yi , Zhou Pengshang , Lin Hengwei , Du Jiaren
Published: September 2024

In recent years, the world has witnessed rapid progress in research on ultraviolet luminescent materials, ranging from high-level anticounterfeiting and solar-blind optical tagging to antibacterial applications. In particular, a background-signal free solar-blind surveillance of ultraviolet-C photons provides an opportunity in bright indoor and outdoor environments. However, ambient daylight or inevitable external photostimulation is always eliminated or underestimated in the research of persistent phosphors. Herein, an in situ trapping–detrapping experimental procedure is employed to reveal more information on the total trap energy and trap modulations after photostimulation. Our findings reveal the presence of optically active trapping defects with photostimulated detrapping and retrapping behavior. This work provides a fundamental advance in revealing the trap distribution and trap reshuffling during glowing-in-the-daylight events, offering what we believe to be new insights into manipulating traps.
Holography optimization based on combining iterative Green’s function algorithm and deep learning method
Authors: Chen Nanxing , Cao Yubin , Li Jianyi , Yang Qingbo , Cao Kairui , Tan Liying
Published: September 2024

In this Letter, we present a novel, to the best of our knowledge, approach that combines a new numerical iterative algorithm with a physics-informed neural network (PINN) architecture to solve the Helmholtz equation, thereby achieving highly generalized refractive index modulation holography. Firstly, we design a non-uniform refractive index convolutional neural network (NRI-CNN) to modify the refractive index and extract a feature vector. Then we propose an iterative Green’s function algorithm (IGFA) to approximately solve the Helmholtz equation. In order to enhance the generalization ability of the solution, the abstracted vector is utilized as a multiplier term in IGFA, obtaining an approximately spatial distribution of the light field. Ultimately, we design a U-net to handle residuals of the Helmholtz equation and phases of optical fields (ERPU-net). We apply this method for holographic reconstructions on random Gaussian beams, beams with image data, and those altered by simulated turbulent phases.
Stereo imaging inspired by bionic optics
Authors: Huang Yi , Cao Jiajing , Shi Xinxin , Wang Junya , Chang Jun
Published: September 2024

Stereo imaging has been a focal point in fields such as robotics and
autonomous driving. This Letter discusses the imaging mechanisms of
jumping spiders and human eyes from a biomimetic perspective and
proposes a monocular stereo imaging solution with low computational
cost and high stability. The stereo imaging mechanism of jumping
spiders enables monocular imaging without relying on multiple
viewpoints, thus avoiding complex large-scale feature point matching
and significantly conserving computational resources. The foveal
imaging mechanism of the human eye allows for complex imaging tasks to
be completed only on the locally interested regions, resulting in more
efficient execution of various visual tasks. By combining these two
advantages, we have developed a more computationally efficient
monocular stereo imaging method that can achieve stereo imaging on
only the locally interested regions without sacrificing the
performance of wide field-of-view (FOV) imaging. Finally, through
experimental validation, we demonstrate that the method proposed in
this Letter exhibits excellent stereo imaging performance.
Proposal for Brillouin microwave-to-optical conversion on a chip [Invited]
Authors: Yang Yuan-Hao , Wang Jia-Qi , Xu Xin-Biao , Li Ming , Zhang Yan-Lei , Pan Xiaoxuan , Xiao Lintao , Wang Weiting , Guo Guang-can , Sun Luyan , Zou Chang-ling
Published: September 2024

We propose a novel scheme for efficient and low-noise microwave-to-optical quantum transduction based on cavity-enhanced Brillouin interaction between telecom photons and 10 gigahertz phonons on a lithium niobate-on-Sapphire chip. By employing a dual-microring cavity design and tailoring the geometry dispersion, triply-resonant and phase-matching conditions can be achieved for the backward Brillouin process, resulting in strong vacuum coupling strengths between the confined phononic and photonic modes. Our numerical analysis, taking into account the material anisotropy of lithium niobate and sapphire, predicts near-unity internal conversion efficiency with only sub-milliwatt pump power. The unsuspended all-solid-state architecture offers superior mechanical stability and robustness, overcoming a major challenge in piezo-optomechanical systems. Furthermore, the broadband nature of the Brillouin process enables multi-channel conversion, a key advantage over existing approaches. This versatile platform opens up exciting opportunities for scalable quantum processors with hybrid photonic-phononic-superconducting integrated circuits.
Noise resilient and accurate target detection using fractional-order Fourier domain correlation
Authors: Papangelakis Georgios , Blakey Phillip , Liu Han , Balaji Bhashyam , Helmy Amr S.
Published: September 2024

Quantum enhanced optical target detection provides a unique route to increased noise resilience of classical LiDARs (laser imaging, detection, and ranging) by using time correlation of non-classical photon pairs. Such enhancement is dictated by the detector temporal uncertainty that is typically orders of magnitude larger than the intrinsic correlation time. To circumvent such detector limitation, we explore the possibility of measuring correlation in the fractional-order Fourier domain (FrFD), which can be realized with the non-local dispersion cancellation. Experimentally, we verify this principle using a fiber-coupled waveguide source of photon pairs, showing enhanced noise rejection as compared with conventional time-domain coincidence detection and classical intensity detection. For false alarm rates of 10−9, an 89 dB improved detection rate is measured using receiver operating characteristics when comparing our FrFD protocol with classical intensity detection. Additionally, we discussed the resilience of FrFD correlation against intentionally prepared counterfeit signal photons. The possibility enabled by measuring correlation in the FrFD should also provide potential benefit for various sensing and communication protocols that relies on coincidence detection.
Calibrating dimension reduction hyperparameters in the presence of noise
Authors: Lin Justin , Fukuyama Julia
Published: September 2024

The goal of dimension reduction tools is to construct a low-dimensional representation of high-dimensional data. These tools are employed for a variety of reasons such as noise reduction, visualization, and to lower computational costs. However, there is a fundamental issue that is discussed in other modeling problems that is often overlooked in dimension reduction—overfitting. In the context of other modeling problems, techniques such as feature-selection, cross-validation, and regularization are employed to combat overfitting, but rarely are such precautions taken when applying dimension reduction. Prior applications of the two most popular non-linear dimension reduction methods, t-SNE and UMAP, fail to acknowledge data as a combination of signal and noise when assessing performance. These methods are typically calibrated to capture the entirety of the data, not just the signal. In this paper, we demonstrate the importance of acknowledging noise when calibrating hyperparameters and present a framework that enables users to do so. We use this framework to explore the role hyperparameter calibration plays in overfitting the data when applying t-SNE and UMAP. More specifically, we show previously recommended values for perplexity and n_neighbors are too small and overfit the noise. We also provide a workflow others may use to calibrate hyperparameters in the presence of noise.
Short-term vital parameter forecasting in the intensive care unit: A benchmark study leveraging data from patients after cardiothoracic surgery
Authors: Hinrichs Nils , Roeschl Tobias , Lanmueller Pia , Balzer Felix , Eickhoff Carsten , O’Brien Benjamin , Falk Volkmar , Meyer Alexander
Published: September 2024

Patients in an Intensive Care Unit (ICU) are closely and continuously monitored, and many machine learning (ML) solutions have been proposed to predict specific outcomes like death, bleeding, or organ failure. Forecasting of vital parameters is a more general approach to ML-based patient monitoring, but the literature on its feasibility and robust benchmarks of achievable accuracy are scarce. We implemented five univariate statistical models (the naïve model, the Theta method, exponential smoothing, the autoregressive integrated moving average model, and an autoregressive single-layer neural network), two univariate neural networks (N-BEATS and N-HiTS), and two multivariate neural networks designed for sequential data (a recurrent neural network with gated recurrent unit, GRU, and a Transformer network) to produce forecasts for six vital parameters recorded at five-minute intervals during intensive care monitoring. Vital parameters were the diastolic, systolic, and mean arterial blood pressure, central venous pressure, peripheral oxygen saturation (measured by non-invasive pulse oximetry) and heart rate, and forecasts were made for 5 through 120 minutes into the future. Patients used in this study recovered from cardiothoracic surgery in an ICU. The patient cohort used for model development (n = 22,348) and internal testing (n = 2,483) originated from a heart center in Germany, while a patient sub-set from the eICU collaborative research database, an American multicenter ICU cohort, was used for external testing (n = 7,477). The GRU was the predominant method in this study. Uni- and multivariate neural network models proved to be superior to univariate statistical models across vital parameters and forecast horizons, and their advantage steadily became more pronounced for increasing forecast horizons. With this study, we established an extensive set of benchmarks for forecast performance in the ICU. Our findings suggest that supplying physicians with short-term forecasts of vital parameters in the ICU is feasible, and that multivariate neural networks are most suited for the task due to their ability to learn patterns across thousands of patients.
Exploring the role of learning goal orientation, instructor reputation, parasocial interaction, and tutor intervention in university students’ MOOC retention: A TAM-TRA based examination
Authors: Wang Siyao , Lee Sang-Khee
Published: September 2024

While MOOC platforms allow universities to implement various strategies such as brand promotion and student recruitment, the alarmingly low retention rate suggests a need to explore the critical factors that influence students’ course retention. So far, studies on MOOC platforms focus either on the students’ individual factors (i.e., students’ personal factors such as perceived value) or situational factors (i.e., external influences shaping students’ behavior, such as system quality) for students’ learning, thus lacking a complete view of those determinant factors. This study integrates the TAM model with the TRA model to analyze the roles of three important antecedents (learning goal orientation; LGO, instructor reputation; IR, & parasocial interaction; PI) on university students’ perceived value (PU) and learning attitude (LA), two critical predictors of MOOC retention (CR). Using data from an online survey of 449 Chinese university students, the hypothesis model was tested using PLS. We found that LGO, IR, and PI each positively affect PU; LGO, IR, and PI each positively affect LA; PU and LA each positively influence course retention (CR), with each impact enhanced by tutor intervention (TI). The theoretical and practical implications of such findings are presented.