bluuebunny/crossref_metadata_2025 huggingface dataset:
The genome sequence of common knotgrass, Polygonum aviculare L. (Polygonaceae)
Authors: Christenhusz Maarten J. M. , Hollingsworth Peter M. ,   Royal Botanic Gardens Kew Genome Acquisition Lab,   Plant Genome Sizing collective,   Darwin Tree of Life Barcoding collective,   Wellcome Sanger Institute Tree of Life Management, Samples and Laboratory team,   Wellcome Sanger Institute Scientific Operations: Sequencing Operations,   Wellcome Sanger Institute Tree of Life Core Informatics team,   Tree of Life Core Informatics collective,   Darwin Tree of Life Consortium
Published: March 2024

We present a genome assembly from an individual Polygonum aviculare (common knotgrass; Eudicot; Magnoliopsida; Caryophyllales; Polygonaceae). The genome sequence is 351.6 megabases in span. Most of the assembly is scaffolded into 10 chromosomal pseudomolecules. The mitochondrial and plastid genome assemblies have lengths of 333.39 kilobases and 163.28 kilobases in length, respectively.
The genome sequence of the big-headed mining bee, Andrena bucephala (Stephens, 1846)
Authors: Crowley Liam M. ,   University of Oxford and Wytham Woods Genome Acquisition Lab,   Darwin Tree of Life Barcoding collective,   Wellcome Sanger Institute Tree of Life Management, Samples and Laboratory team,   Wellcome Sanger Institute Scientific Operations: Sequencing Operations,   Wellcome Sanger Institute Tree of Life Core Informatics team,   Tree of Life Core Informatics collective,   Darwin Tree of Life Consortium
Published: March 2024

We present a genome assembly from an individual female Andrena bucephala (the Big-headed Mining Bee; Arthropoda; Insecta; Hymenoptera; Andrenidae). The genome sequence is 379.8 megabases in span. Most of the assembly is scaffolded into 5 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 19.57 kilobases in length. Gene annotation of this assembly on Ensembl identified 12,022 protein coding genes.
The genome sequence of the Annual Mercury, Mercurialis annua L., 1753 (Euphorbiaceae)
Authors: Christenhusz Maarten J. M. , Pannell John R. , Twyford Alex D. ,   Royal Botanic Gardens Kew Genome Acquisition Lab,   Plant Genome Sizing collective,   Darwin Tree of Life Barcoding collective,   Wellcome Sanger Institute Tree of Life programme,   Wellcome Sanger Institute Scientific Operations: DNA Pipelines collective,   Tree of Life Core Informatics collective,   Darwin Tree of Life Consortium
Published: March 2024

We present a genome assembly from a diploid female Mercurialis annua (the Annual Mercury; Tracheophyta; Magnoliopsida; Malpighiales; Euphorbiaceae). The genome sequence is 453.2 megabases in span. Most of the assembly is scaffolded into 8 chromosomal pseudomolecules, including the X chromosome. The organelle genomes have also been assembled, and the mitochondrial genome is 435.28 kilobases in length, while the plastid genome is 169.65 kilobases in length.
The genome sequence of a parasitoid wasp, Gasteruption jaculator (Linnaeus, 1758)
Authors: Lawniczak Mara K.N. , Broad Gavin R. ,   Darwin Tree of Life Barcoding collective,   Wellcome Sanger Institute Tree of Life Management, Samples and Laboratory team,   Wellcome Sanger Institute Scientific Operations: Sequencing Operations,   Wellcome Sanger Institute Tree of Life Core Informatics team,   Tree of Life Core Informatics collective,   Darwin Tree of Life Consortium
Published: March 2024

We present a genome assembly from an individual female Gasteruption jaculator (parasitoid wasp; Arthropoda; Insecta; Hymenoptera; Gasteruptiidae). The genome sequence is 275.6 megabases in span. Most of the assembly is scaffolded into 16 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 19.67 kilobases in length. Gene annotation of this assembly on Ensembl identified 19,924 protein coding genes.
The genome sequence of field madder, Sherardia arvensis L., 1753 (Rubiaceae)
Authors: Christenhusz Maarten J. M. ,   Royal Botanic Gardens Kew Genome Acquisition Lab,   Plant Genome Sizing collective,   Darwin Tree of Life Barcoding collective,   Wellcome Sanger Institute Tree of Life Management, Samples and Laboratory team,   Wellcome Sanger Institute Scientific Operations: Sequencing Operations,   Wellcome Sanger Institute Tree of Life Core Informatics team,   Tree of Life Core Informatics collective,   Darwin Tree of Life Consortium
Published: March 2024

We present a genome assembly from an individual Sherardia arvensis (field madder; Tracheophyta; Magnoliopsida; Gentianales; Rubiaceae). The genome sequence is 440.9 megabases in span. Most of the assembly is scaffolded into 11 chromosomal pseudomolecules. The mitochondrial and plastid genome assemblies have lengths of 203.98 kilobases and 152.73 kilobases in length, respectively.
The genome sequence of a soldier beetle, Malthinus flaveolus (Herbst, 1786)
Authors: Telfer Mark G. , Geiser Michael F. ,   University of Oxford and Wytham Woods Genome Acquisition Lab,   Darwin Tree of Life Barcoding collective,   Wellcome Sanger Institute Tree of Life Management, Samples and Laboratory team,   Wellcome Sanger Institute Scientific Operations: Sequencing Operations,   Wellcome Sanger Institute Tree of Life Core Informatics team,   Tree of Life Core Informatics collective,   Darwin Tree of Life Consortium
Published: March 2024

We present a genome assembly from an individual female Malthinus flaveolus (soldier beetle; Arthropoda; Insecta; Coleoptera; Cantharidae). The genome sequence is 236.7 megabases in span. Most of the assembly is scaffolded into 6 chromosomal pseudomolecules, including the X sex chromosome. The mitochondrial genome has also been assembled and is 19.27 kilobases in length. Gene annotation of this assembly on Ensembl identified 16,617 protein coding genes.
Murals as an element of the tourist image of the city of Odesa
Authors: Prykhodko Z. , Yavorska L. , Shashero A. , Nefedova N. , Molodetskyi A.
Published: March 2024

The article discusses in detail the latest objects of tourist display of the city of Odessa - murals. These works of art increase the aesthetic appeal of the city's districts, promote cultural heritage and promote the development of tourism in the area, and ultimately, together with other recreational and tourism facilities, influence the formation of the tourist image of the city. Thus, the development and development of excursions with the involvement of a kind of urban art – murals, will contribute to the restoration of tourist activities in the city in peacetime.
In Lieu of Introduction
Authors: Galewicz Cezary
Published: March 2024

No abstract is avaliable for this article.
The Veda and the Patronage Economy of the Hindu Temple
Authors: Galewicz Cezary
Published: March 2024

The ambiguous relationship between the Veda and Hinduism has attracted considerable scholarship. So have recent cases of revival and redesigning of Vedic ritualism. Much less has been written on the concepts, forms and actual practices of the coexistence of temple ritual and the Veda within the territory of the Hindu temple. This relationship, by no means homogenous and not easy to articulate, must often have been problematic while engaging issues of identity, eligibility, agency, economy and power. It remains relevant to contemporary national Hinduism and political scene. From the early years of temple Hinduism, the presence of the Veda in the Hindu temple depended on a dynamic process of inclusion and exclusion with prestige game, status aspiration and competition among ritual agents. To make sense of this relationship, the essay proposes a historically in-formed perspective set against a background of regional patterns of pat-ronage and temple economy while addressing a variety of such relation-ships from historical Malabar (today‘s Kerala) with a focus on the temple ritual of vāraṃ.
Unworthy Recipients and the Mercy of God
Authors: Zapart Jarosław
Published: March 2024

This article examines the ideology of gift in the Sant hagiographies (paracaī) of Anantadās (16th/17th century). It is assumed that understanding author’s implicit view of gift giving (dāna) is fundamental to unraveling the meaning of certain episodes of the paracaīs. These involve curious cases such as that of Kabīr abandoning his dāna-related duties or those of various Sants, for example, Pīpā, offering gifts to the brahmins (who are, nevertheless, depicted mainly as enemies of the bhakts). The approach of Anantadās to dāna seems to differ significantly from the ideas expounded by the medieval Brahmanic, Buddhist, and Jain sources as it transcends the notion of the gift as being motivated by the socioreligious status of the recipient. It also proves the existence of a certain God-bhakt reciprocity. As such, dāna works on a soteriological level, as a devotional act aimed at creating a relationship with Hari, and on a proselytic level as a tool for expanding the religious community.
Aggregating Distributed Energy Resources: Efficiency and Market Power
Authors: Gao Zuguang , Alshehri Khaled , Birge John R.
Published: March 2024

Problem definition: The rapid expansion of distributed energy resources (DERs) is one of the most significant changes to electricity systems around the world. Examples of DERs include solar panels, electric storage, thermal storage, and combined heat and power plants. Because of the small supply capacities of these DERs, it is impractical for them to participate directly in the wholesale electricity market. We study in this paper the question of how to integrate these DER supplies into the electricity market, with the objective of achieving full market efficiency. Methodology/results: We study four aggregation models, where there is an aggregator who, with the knowledge of DERs’ utility functions and generations, procures electricity from DERs, and sells them in the wholesale market. In the first aggregation model, a profit-maximizing aggregator announces a differential two-part pricing policy to the DER owners. We show that this model preserves full market efficiency, that is, the social welfare achieved by this model is the same as that when DERs participate directly in the wholesale market. In the second aggregation model, the profit-seeking aggregator is forced to impose a uniform two-part pricing policy to prosumers from the same location, and we numerically show that there can be large efficiency loss. In the third (fourth) aggregation model, a uniform (semiuniform) two-part pricing policy is applied to DER owners, whereas the aggregator becomes fully regulated but is guaranteed nonnegative (positive) profit. It is shown that these models again achieve full market efficiency. Furthermore, we show that DER aggregation also leads to a reduction in the market power of conventional generators. Managerial implications: DER aggregation via profit-seeking and/or regulated aggregators has been investigated by California Independent System Operator and New York Independent System Operator, among others, and the recent Federal Energy Regulatory Commission Order No. 2222 paved the way for aggregators to bid in the wholesale market. Our four aggregation models may shed light on how DERs should be included in the wholesale electricity market.

Funding: This work was supported by the King Fahd University of Petroleum and Minerals [Grant INML2106] and the National Science Foundation [Grant 1832230].

Supplemental Material: The online appendices are available at https://doi.org/10.1287/msom.2021.0539 .
Factors associated with decreased length of stay following robotic arm-assisted and conventional total hip arthroplasty
Authors: Fontalis Andreas , Wignadasan Warran , Mancino Fabio , The Crystallynn S. , Magan Ahmed , Plastow Ricci , Haddad Fares S.
Published: March 2024

Aims

Postoperative length of stay (LOS) and discharge dispositions following arthroplasty can be used as surrogate measurements for improvements in patients’ pathways and costs. With the increasing use of robotic technology in arthroplasty, it is important to assess its impact on LOS. The aim of this study was to identify factors associated with decreased LOS following robotic arm-assisted total hip arthroplasty (RO THA) compared with the conventional technique (CO THA).

Methods

This large-scale, single-institution study included 1,607 patients of any age who underwent 1,732 primary THAs for any indication between May 2019 and January 2023. The data which were collected included the demographics of the patients, LOS, type of anaesthetic, the need for treatment in a post-anaesthesia care unit (PACU), readmission within 30 days, and discharge disposition. Univariate and multivariate logistic regression models were used to identify factors and the characteristics of patients which were associated with delayed discharge.

Results

The multivariate model identified that age, female sex, admission into a PACU, American Society of Anesthesiologists grade > II, and CO THA were associated with a significantly higher risk of a LOS of > two days. The median LOS was 54 hours (interquartile range (IQR) 34 to 78) in the RO THA group compared with 60 hours (IQR 51 to 100) in the CO THA group (p < 0.001). The discharge dispositions were comparable between the two groups. A higher proportion of patients undergoing CO THA required PACU admission postoperatively, although without reaching statistical significance (7.2% vs 5.2%, p = 0.238).

Conclusion

We found that among other baseline characteristics and comorbidities, RO THA was associated with a significantly shorter LOS, with no difference in discharge destination. With the increasing demand for THA, these findings suggest that robotic assistance in THA could reduce costs. However, randomized controlled trials are required to investigate the cost-effectiveness of this technology.

Cite this article: Bone Joint J 2024;106-B(3 Supple A):24–30.
Threshold for anterior acetabular component overhang correlated with symptomatic iliopsoas impingement after total hip arthroplasty
Authors: Baujard Alexandre , Martinot Pierre , Demondion Xavier , Dartus Julien , Faure Philippe A. , Girard Julien , Migaud Henri
Published: March 2024

Aims

Mechanical impingement of the iliopsoas (IP) tendon accounts for 2% to 6% of persistent postoperative pain after total hip arthroplasty (THA). The most common initiator is anterior acetabular component protrusion, where the anterior margin is not covered by anterior acetabular wall. A CT scan can be used to identify and measure this overhang; however, no threshold exists for determining symptomatic anterior IP impingement due to overhang. A case-control study was conducted in which CT scan measurements were used to define a threshold that differentiates patients with IP impingement from asymptomatic patients after THA.

Methods

We analyzed the CT scans of 622 patients (758 THAs) between May 2011 and May 2020. From this population, we identified 136 patients with symptoms suggestive of IP impingement. Among them, six were subsequently excluded: three because the diagnosis was refuted intraoperatively, and three because they had another obvious cause of impingement, leaving 130 hips (130 patients) in the study (impingement) group. They were matched to a control group of 138 asymptomatic hips (138 patients) after THA. The anterior acetabular component overhang was measured on an axial CT slice based on anatomical landmarks (orthogonal to the pelvic axis).

Results

The impingement group had a median overhang of 8 mm (interquartile range (IQR) 5 to 11) versus 0 mm (IQR 0 to 4) for the control group (p < 0.001). Using receiver operating characteristic curves, an overhang threshold of 4 mm was best correlated with a diagnosis of impingement (sensitivity 79%, specificity 85%; positive predictive value 75%, negative predictive value 85%).

Conclusion

Pain after THA related to IP impingement can be reasonably linked to acetabular overhang if it exceeds 4 mm on a CT scan. Below this threshold, it seems logical to look for another cause of IP irritation or another reason for the pain after THA before concluding that impingement is present.

Cite this article: Bone Joint J 2024;106-B(3 Supple A):97–103.
Should high-risk patients seek out care from high-volume surgeons?
Authors: Thomas Jeremiah , Ashkenazi Itay , Lawrence Kyle W. , Davidovitch Roy I. , Rozell Joshua C. , Schwarzkopf Ran
Published: March 2024

Aims

Patients with a high comorbidity burden (HCB) can achieve similar improvements in quality of life compared with low-risk patients, but greater morbidity may deter surgeons from operating on these patients. Whether surgeon volume influences total hip arthroplasty (THA) outcomes in HCB patients has not been investigated. This study aimed to compare complication rates and implant survivorship in HCB patients operated on by high-volume (HV) and non-HV THA surgeons.

Methods

Patients with Charlson Comorbidity Index ≥ 5 and American Society of Anesthesiologists grade of III or IV, undergoing primary elective THA between January 2013 and December 2021, were retrospectively reviewed. Patients were separated into groups based on whether they were operated on by a HV surgeon (defined as the top 25% of surgeons at our institution by number of primary THAs per year) or a non-HV surgeon. Groups were propensity-matched 1:1 to control for demographic variables. A total of 1,134 patients were included in the matched analysis. Between groups, 90-day readmissions and revisions were compared, and Kaplan-Meier analysis was used to evaluate implant survivorship within the follow-up period.

Results

Years of experience were comparable between non-HV and HV surgeons (p = 0.733). The HV group had significantly shorter surgical times (p < 0.001) and shorter length of stay (p = 0.009) than the non-HV group. The HV group also had significantly fewer 90-day readmissions (p = 0.030), all-cause revisions (p = 0.023), and septic revisions (p = 0.020) compared with the non-HV group at latest follow-up. The HV group had significantly greater freedom from all-cause (p = 0.023) and septic revision (p = 0.020) than the non-HV group.

Conclusion

The HCB THA patients have fewer 90-day readmissions, all-cause revisions, and septic revisions, as well as shorter length of stay when treated by HV surgeons. THA candidates with a HCB may benefit from referral to HV surgeons to reduce procedural risk and improve postoperative outcomes.

Cite this article: Bone Joint J 2024;106-B(3 Supple A):10–16.
Influence of the type of stem and its fixation on revision and immediate postoperative mortality in elective total hip arthroplasty
Authors: Morlock Michael , Perka Carsten , Melsheimer Oliver , Kirschbaum Stephanie M.
Published: March 2024

Aims

Despite higher rates of revision after total hip arthroplasty (THA) being reported for uncemented stems in patients aged > 75 years, they are frequently used in this age group. Increased mortality after cemented fixation is often used as a justification, but recent data do not confirm this association. The aim of this study was to investigate the influence of the design of the stem and the type of fixation on the rate of revision and immediate postoperative mortality, focusing on the age and sex of the patients.

Methods

A total of 333,144 patients with primary osteoarthritis (OA) of the hip who underwent elective THA between November 2012 and September 2022, using uncemented acetabular components without reconstruction shells, from the German arthroplasty registry were included in the study. The revision rates three years postoperatively for four types of stem (uncemented, uncemented with collar, uncemented short, and cemented) were compared within four age groups: < 60 years (Young), between 61 and 70 years (Mid-I), between 71 and 80 years (Mid-II), and aged > 80 years (Old). A noninferiority analysis was performed on the most frequently used designs of stem.

Results

The design of the stem was found to have no significant influence on the rate of revision for either sex in the Young group. Uncemented collared stems had a significantly lower rate of revision compared with the other types of stem for females in the Mid-I group. There was a significantly higher rate of revision for uncemented stems in females in the Mid-II group compared with all other types of stem, while in males the rate for uncemented stems was only significantly higher than the rate for cemented stems. Cemented stems had a significantly lower revision rate compared with uncemented and short stems for both sexes in the Old cohort, as did females with collared stems. The rate of immediate postoperative mortality was similar for all types of stem in the Old age group, as were the American Society of Anesthesiologists grades.

Conclusion

In patients aged > 80 years, uncemented and short stems had significantly higher revision rates compared with cemented and collared stems, especially in females. The design of the stem and type of fixation have to be analyzed in more detail than only considering cemented and uncemented fixation, in order to further improve the success of THA.

Cite this article: Bone Joint J 2024;106-B(3 Supple A):130–136.
Magnetically driven antegrade intramedullary lengthening nails for tibial lengthening
Authors: Vogt Bjoern , Lueckingsmeier Milena , Gosheger Georg , Laufer Andrea , Toporowski Gregor , Antfang Carina , Roedl Robert , Frommer Adrien
Published: March 2024

Aims

As an alternative to external fixators, intramedullary lengthening nails (ILNs) can be employed for distraction osteogenesis. While previous studies have demonstrated that typical complications of external devices, such as soft-tissue tethering, and pin site infection can be avoided with ILNs, there is a lack of studies that exclusively investigated tibial distraction osteogenesis with motorized ILNs inserted via an antegrade approach.

Methods

A total of 58 patients (median age 17 years (interquartile range (IQR) 15 to 21)) treated by unilateral tibial distraction osteogenesis for a median leg length discrepancy of 41 mm (IQR 34 to 53), and nine patients with disproportionate short stature treated by bilateral simultaneous tibial distraction osteogenesis, with magnetically controlled motorized ILNs inserted via an antegrade approach, were retrospectively analyzed. The median follow-up was 37 months (IQR 30 to 51). Outcome measurements were accuracy, precision, reliability, bone healing, complications, and patient-reported outcome assessed by the Limb Deformity-Scoliosis Research Society Score (LD-SRS-30).

Results

A median tibial distraction of 44 mm (IQR 31 to 49) was achieved with a mean distraction index of 0.5 mm/day (standard deviation 0.13) and median consolidation index of 41.2 days/cm (IQR 34 to 51). Accuracy, precision, and reliability were 91%, 92%, and 97%, respectively. New temporary range of motion limitations occurred in 51% of segments (34/67). Distraction-related equinus deformity treated by Achilles tendon lengthening was the most common major complication recorded in 16% of segments (11/67). In 95% of patients (55/58) the distraction goal was achieved with 42% unplanned additional interventions per segment (28/67). The median postoperative LD-SRS-30 score was 4.0 (IQR 3.6 to 4.3).

Conclusion

Tibial distraction osteogenesis using motorized ILNs inserted via an antegrade approach appears to be a reliable and precise procedure. Temporary joint stiffness of the knee or ankle should be expected in up to every second patient. A high rate and wide range of complications of variable severity should be anticipated.

Cite this article: Bone Joint J 2024;106-B(3):293–302.
Orthopaedic management of children with spinal dysraphism
Authors: Pinto Deepika , Hussain Sabba , Leo Donato G. , Bridgens Anna , Eastwood Deborah , Gelfer Yael
Published: March 2024

Aims

Children with spinal dysraphism can develop various musculoskeletal deformities, necessitating a range of orthopaedic interventions, causing significant morbidity, and making considerable demands on resources. This systematic review aimed to identify what outcome measures have been reported in the literature for children with spinal dysraphism who undergo orthopaedic interventions involving the lower limbs.

Methods

A PROSPERO-registered systematic literature review was performed following PRISMA guidelines. All relevant studies published until January 2023 were identified. Individual outcomes and outcome measurement tools were extracted verbatim. The measurement tools were assessed for reliability and validity, and all outcomes were grouped according to the Outcome Measures Recommended for use in Randomized Clinical Trials (OMERACT) filters.

Results

From 91 eligible studies, 27 individual outcomes were identified, including those related to clinical assessment (n = 12), mobility (n = 4), adverse events (n = 6), investigations (n = 4), and miscellaneous (n = 1). Ten outcome measurement tools were identified, of which Hoffer’s Functional Ambulation Scale was the most commonly used. Several studies used unvalidated measurement tools originally developed for other conditions, and 26 studies developed new measurement tools. On the OMERACT filter, most outcomes reported pathophysiology and/or the impact on life. There were only six patient- or parent-reported outcomes, and none assessed the quality of life.

Conclusion

The outcomes that were reported were heterogenous, lack validation and failed to incorporate patient or family perceptions. Until outcomes can be reported unequivocally, research in this area will remain limited. Our findings should guide the development of a core outcome set, which will allow consistency in the reporting of outcomes for this condition.

Cite this article: Bone Joint J 2024;106-B(3):277–285.
PADRÕES ESPACIAIS DA MOBILIDADE DE TRABALHADORES QUALIFICADOS NAS REGIÕES BRASILEIRAS
Authors: Ribeiro Costa Ariana , Garcia Renato
Published: March 2024

A mobilidade de trabalhadores qualificados representa uma das mais importantes formas de geração de transbordamentos locais de conhecimento, uma vez que trabalhadores qualificados possuem a capacidade de incrementar a geração e a difusão de novos conhecimentos nas regiões. Nessa linha, o objetivo deste artigo é apresentar os padrões de mobilidade espacial dos trabalhadores qualificados nas regiões brasileiras. A partir dos microdados da RAIS no período 2009-2014 foi possível mapear a mobilidade desses trabalhadores entre microrregiões em todo o país. Os resultados contribuem para o debate sobre os padrões de movimentação de trabalhadores qualificados, com efeitos importantes sobre o desenvolvimento regional. Os resultados apontam que a Região Metropolitana de São Paulo, algumas capitais de estados e cidades médias brasileiras foram as regiões que mais receberam trabalhadores qualificados, com destaque para regiões que são mais diversificadas e possuem maior número de atividades tecnológicas. Adicionalmente, observou-se que os trabalhadores qualificados se movem percentualmente mais do que os totais.
The first year of an early years consultant network in colorectal surgery at the interface of mentorship and leadership
Authors: Panagiotopoulou I , Adams K , Aslam I , Bhalla A , Boereboom C , Quyn A , Sutton P , Williamson J , Brown S , Fearnhead N , Maxwell-Armstrong C ,   On behalf of the Early Years Consultant Network of the Association of Coloproctology of Great Britain and Ireland
Published: March 2024

The Early Years Consultant Network (EYCN) was created within the Association of Coloproctology of Great Britain and Ireland in order to help new colorectal consultants in their transition to consultant practice. EYCN aims to fill the training gap in leadership and provide mentorship for surgeons during their first five years of independent practice. During its inaugural year, EYCN worked at the interface of leadership and mentorship as the two seem intertwined.
Influence of diffraction distance on image restoration in deep learning networks
Authors: Huang Shihong , Yang Yanxu , Wu Jiayang , Lin Caihou
Published: March 2024

In recent years, significant advancements have been made in the field of computational imaging, particularly due to the application of deep learning methods to imaging problems. However, only a few studies related to deep learning have examined the impact of diffraction distance on image restoration. In this paper, the effect of diffraction distance on image restoration is investigated based on the PhysenNet neural network. A theoretical framework for diffraction images at various diffraction distances is provided along with the applicable propagators. In the experiment, the PhysenNet network is selected to train on diffraction images with different distances and the impact of using different propagators on network performance is studied. Optimal propagators required to recover images at different diffraction distances are determined. Insights obtained through these experiments can expand the scope of neural networks in computational imaging.
Design of a dynamic target simulator optical system with a large FOV and long exit pupil distance
Authors: Cao Tuo , Wang Ling Yun
Published: March 2024

According to new generation missile test and detection requirements, it is necessary to introduce hardware-in-the-loop (HIL) simulation technology to realize the performance test of the seeker. This paper introduces the concept of secondary imaging and uses the method of focal distance allocation so that the optical system field of view (FOV) can still be greater than 6°, under the condition that the exit pupil distance is larger than 800 mm and a high-quality lighting system is designed. The design results show that when the exit pupil distance of the system is 1000 mm and the FOV is 6.4°, the modulation transfer function (MTF) of the system is 60lp/mm>0.4, and the distortion is less than 0.1%. The uniformity of the illumination system is greater than 90%, meeting the requirements of the design index.
Magneto-optical fiber-based orbital angular momentum mode converters
Authors: Chen Geng , Wu Baojian , Wang Qiquan , Wen Feng , Qiu Kun
Published: March 2024

Orbital angular momentum (OAM) mode division multiplexing (MDM) systems can support large-capacity and high-speed rate information transmission, in which the OAM mode conversion devices play an important role. In this paper, the mode conversion principle of magneto-optical fiber-based long-period grating (MOF-LPG) is analyzed for further developing new magneto-optical (MO) OAM mode converters, including three types of CP01 to OAM±1,1, OAM±1,1 to OAM±2,1, and OAM±1,1 to CP02. It is shown that the magnetic tunability of the mode converters through the propagation constants of the eigenmodes is useful for compensating for process errors and increasing the operating wavelength range. The implementation of MOF-LPGs is also discussed from the aspect of the prospective experiments.
Uncertainty of digital image correlation under video compression and DSP optimization
Authors: Li Xiaowen , Tang Xinqiao , Xu Yinuo , Sun Wei , Chen Zhenning
Published: March 2024

The storage and transmission of videos at high spatial resolution remain a great challenge in image-based optical techniques. The uncertainty of digital image correlation (DIC) was assessed following speckle video compression under High Efficiency Video Coding (HEVC/H.265). First, the evaluation criterion for the DIC accuracy affected by compression was provided. The stability of H.265 video compression in DIC was studied considering different compressed frames under different target quantization parameters (QPs) and compression ratios (CRs). The deformation uncertainty of the DIC itself as affected by H.265 video compression was further investigated through uniform translation and non-uniform sinusoidal deformation performance. Moreover, the optimized digital speckle pattern (DSP) was re-evaluated considering video compression-induced uncertainty. DSPs with parameters of different diameters and randomness were compressed using various QPs and CRs. In addition, DSP evaluation was performed under both translation and non-homogeneous deformation conditions. The feasibility of the re-optimized DSP under H.265 video compression was validated using a defective bending beam, and DSP videos with a speckle size of 8 pixels reached a high CR within an acceptable margin of error.
Down-conversion and frequency spectrum convolution of the broadband signal based on active mode-locking technology
Authors: Xiong Feng , Wang Yibei , Wang Yalan , Wang Dangwei , Liu Runhua , Du Pengfei , Zhang Jin , Wang Anle , Cong Haixia , Peng Xiaoniu
Published: March 2024

A multifunction processor for a broadband signal based on the active mode-locking optoelectronic oscillator (OEO) is proposed and experimentally demonstrated. The central frequency down-conversion and frequency spectrum convolution of the target broadband signal (TBS) are realized by just tuning the wavelength of the optical carrier or by the time domain product, respectively. To achieve the central frequency down-conversion of the TBS, an optical tunable delay line (OTDL) is adopted to match the delay time of the OEO loop with the repetition period of the TBS. Then the spectrum convolution of the TBS is produced by just injecting a lower frequency signal consistent with the free spectral range (FSR) of the OEO loop. Moreover, the frequency convolution repetition is also greatly increased by harmonic mode-locking injection. The equivalent bandwidth of the TBS is enlarged by ∼50 times, benefiting from the frequency convolution. The central frequency conversion flexibility and the bandwidth compatibility are also discussed in detail. This work provides a multifunction processor system and may have potential usage in multifunctional integrated radar systems.
Phase screen prediction using deep phase network for FSO links
Authors: Li Ming , Wu Zhigeng , Wang Tianyi , Zhang Pengxin , Cvijetic Milorad
Published: March 2024

Due to the presence of air turbulence in free-space optical (FSO) links, random
fluctuations in wavefront phase and amplitude of the optical signal
are reduced after it propagates through the air channel, which
degrades the performance of free-space optical communication (FSOC)
systems. Phase screen reflects the phase distortions resulting from
air turbulence. Accordingly, accurate prediction with respect to phase
screen is of significance for the FSOC. In this paper, we propose a
phase screen prediction method based on the deep phase network (DPN).
The advantages of the proposed method include strong robustness
against air turbulence, low model depth, and fewer parameters as well
as low complexity. The results reveal that our DPN enables desired
inference accuracy and faster inference speed compared with the
existing models, by combining the mean square deviation loss function
with the pixel penalty terms. More concretely, the accuracy of phase
screen prediction can reach up to 95%; further, the average time
consumed to predict the phase screen is in the order of milliseconds
only under various turbulence conditions. Also, our DPN outperforms
the traditional Gerchberg–Saxton algorithm in
convergence speed.
High-enhancement photoluminescence of monolayer MoS2 in hybrid plasmonic systems
Authors: Huang Yan , Kanyang Ruoying , Fang Cizhe , Li Xiaoxi , Zeng Xiangyu , Wang Yibo , Liu Yan , Hao Yue , Han Genquan
Published: March 2024

Monolayer molybdenum disulfide (MoS2) has a weak light-matter interaction due to ultrathin thickness, which limits its potential application in lasing action. In this study, we propose a hybrid structure consisting of a nanocavity and Au nanoparticles to enhance the photon emission efficiency of monolayer MoS2. Numerical simulations show that photoluminescence (PL) emission is significantly enhanced by introducing localized surface plasmon resonance (LSPR) to the proposed structure. Furthermore, an exciton energy band system is proposed to elucidate the physical mechanism of the PL process. By optimizing the spacer thickness, a high Purcell enhancement factor of 95 can be achieved. The results provided by this work pave the way to improve the PL efficiency of two-dimensional (2D) material, which constitutes a significant step towards the development of nanodevices such as nanolasers and sensors.
Optical information hiding for different surface images
Authors: Mi ZhaoKe , Zhu YuSi , Zhu YuPeng , Zhang TianHao , Huang Zhengzhong , Wu Fengming , Ke Changjun , Ge SiQin , Rong Lu , Shi YiShi
Published: March 2024

Optical hiding often requires the selection of specific artificial optical components as carriers, which results in poor versatility of the carriers and high costs for the hiding system. To conceal secret information on different surfaces such as metal, wood, and paper, we propose an optical information hiding method. In this method, we use images of surfaces, whose grayscale histograms have the characteristic of symmetric distribution. Based on this characteristic, we first scramble the surface image, and then adjust part of the gray value of the surface image to the complementary value to embed the secret information into a scrambled surface image to generate a key image. In the extraction process, a projector is used to reproduce the scrambled surface image and the key image, which are then incoherently superimposed to extract the secret information using the human visual system. The extraction process does not require complex optical knowledge and is simple and feasible. Simulation experiments and optical experiments indicate that this method is applicable in practice and possesses good security and imperceptibility. Furthermore, we prove the reliability of this method by embedding secret information in different surface images, demonstrating the potential application of more surface images in the field of optical information hiding. Finally, we discuss the applicability of surface information images and analyze the imperceptibility of key images.
On the quantitative analysis of lamellar collagen arrangement with second-harmonic generation imaging
Authors: Guimarães Pedro , Morgado Miguel , Batista Ana
Published: March 2024

Second harmonic generation (SHG) allows for the examination of collagen structure in collagenous tissues. Collagen is a fibrous protein found in abundance in the human body, present in bones, cartilage, the skin, and the cornea, among other areas, providing structure, support, and strength. Its structural arrangement is deeply intertwined with its function. For instance, in the cornea, alterations in collagen organization can result in severe visual impairments. Using SHG imaging, various metrics have demonstrated the potential to study collagen organization. The discrimination between healthy, keratoconus, and crosslinked corneas, assessment of injured tendons, or the characterization of breast and ovarian tumorous tissue have been demonstrated. Nevertheless, these metrics have not yet been objectively evaluated or compared. A total of five metrics were identified and implemented from the literature, and an additional approach adapted from texture analysis was proposed. In this study, we analyzed their effectiveness on a ground-truth set of artificially generated fibrous images. Our investigation provides the first comprehensive assessment of the performance of multiple metrics, identifying both the strengths and weaknesses of each approach and providing valuable insights for future applications of SHG imaging in medical diagnostics and research.
Wavefront aberration determination in non-axially symmetrical optical systems
Authors: Lin Psang Dain
Published: March 2024

Non-axially symmetrical optical systems can provide better solutions to several optical design problems. However, determining their wavefront aberrations is challenging due to the great diversity of their configurations. Accordingly, in the present study, the optical path length (OPL) between two boundaries in a non-axially symmetrical system is expanded by a Taylor series expansion with respect to the base ray. This expansion converts the OPL from a deep composite function to a polynomial form. The various order wavefront aberrations are then obtained from the coefficients of the polynomials in terms of the system independent variables. The proposed method is equally valid for axially symmetrical systems provided that the object is placed on the meridional plane. Overall, the method provides a systematic approach for analyzing the wavefront aberrations in a wide range of optical systems.
Bootstrap geometric ground calibration method for wide angle star sensors
Authors: Teague Samuel , Chahl Javaan
Published: March 2024

Wide angle star sensors are becoming more prevalent in aeronautics. A wide angle lens provides a greater field of view for star detection, but consequently incurs significant lens distortion. The effects of distortion complicate star identification, causing algorithms to fail or report false identifications. We address the issue of calibrating a wide angle star sensor without any specialized equipment, by analyzing two time-separated images captured from a static camera. An initial estimate of the focal length is obtained by observing the displacement of stars between the images. The focal length is subsequently used to build an initial estimate of camera intrinsics, and to identify stars in the image. A RANSAC-augmented Kabsch algorithm is implemented to determine camera orientation, while simultaneously removing false identifications. The identified stars are used to provide a precise estimate of camera focal length, before applying non-linear optimization in a radial search algorithm. The methodology was tested on two cameras, demonstrating the effectiveness of this algorithm in achieving a precise geometric calibration using real hardware, without any specialized calibration equipment.
Second harmonic generation of visible vortex laser based on a waveguide-grating emitter in LBO
Authors: Chen Zhixiang , Liu Hongliang , Lu Qingming , Lv Jinman , Jia Yuechen , Chen Feng
Published: March 2024

In this work, we propose a practical solution to visible vortex laser emission at 532 nm based on second harmonic generation (SHG) in a well-designed waveguide-grating structure. Such an integrated structure is fabricated by femtosecond laser direct writing (FsLDW) in an LBO crystal. Confocal micro-Raman spectroscopy is employed for detailed analysis of FsLDW-induced localized crystalline damage. By optical excitation at 1064 nm, the guiding properties, SHG performance, as well as vortex laser generation of the waveguide-grating hybrid structure are systematically studied. Our results indicate that FsLDW waveguide-grating emitter is a reliable design holding great promise for nonlinear vortex beam generation in integrated optics.
DSCNet: lightweight and efficient self-supervised network via depthwise separable cross convolution blocks for speckle image matching
Authors: Li Lin , Wang Peng , Wang Lingrui , Sun Changku , Fu Luhua
Published: March 2024

Speckle structured light has become a research hotspot due to its ability to acquire target three-dimensional information with single image projection in recent years. To address the challenges of a low number of extracted speckle feature points, high mismatch rate and poor real-time performance in traditional algorithms, as well as the obstacle of requiring expensive annotation data in deep learning-based methods, a lightweight and efficient self-supervised convolutional neural network (CNN) is proposed to achieve high-precision and rapid matching of speckle images. First, to efficiently utilize the speckle projection information, a feature extraction backbone based on the depthwise separable cross convolution blocks is proposed. Second, in the feature detection module, a softargmax detection head is designed to refine the coordinates of speckle feature points to sub-pixel accuracy. In the feature description module, a coarse-to-fine module is presented to further refine matching accuracy. Third, we adopt strategies of transfer learning and self-supervised learning to improve the generalization and feature representation capabilities of the model. Data augmentation and real-time training techniques are used to improve the robustness of the model. The experimental results show that the proposed method achieves a mean matching accuracy of 91.62% for speckle feature points on the pilot’s helmet, with mere 0.95% mismatch rate. The full model runs at 42ms for a speckle image pair on an RTX 3060.
Cladding-pumped laser and amplifier for E- and S-bands based on multimode bismuth-doped graded-index fibers: toward “watt-level” output power
Authors: Vakhrushev Alexander , Umnikov Andrey , Dostovalov Alexander , Riumkin Konstantin , Alyshev Sergey , Firstova Elena , Khegai Aleksandr , Melkumov Mikhail , Babin Sergey , Firstov Sergei
Published: March 2024

In this Letter, we investigated the potential scalability of output power of a cladding-pumped laser and a power amplifier (booster) based on a multimode Bi-doped fiber (BDF) using the mode-selection approach. We fabricated the multimode double-clad graded-index (GRIN) fiber with a confined Bi-doped germanosilicate glass core with a diameter of ≈30 and ≈60 µm. Using femtosecond (fs) inscription technology with high spatial resolution, Bragg gratings of a special transverse structure allowing the selection of low-order modes were written into the core of BDFs. The operation features of the cladding-pumped multimode bismuth-doped GRIN fiber lasers with the inscribed Bragg gratings with various reflection coefficients were investigated. In addition, the behavior of the output power and the beam quality (M2 parameter) of the optical radiation of the developed devices was studied. The CW laser and booster operating at nearly 1.45 µm with maximum output powers of ≈0.8 and ≈1 W, respectively, based on the 60-µm-core BDF under pumping by multimode laser diodes at 808 nm were developed, which are, to the best of our knowledge, the most powerful cladding-pumped BDF devices to date. Near single-mode lasing (M2 <1.3) is demonstrated for a 30-µm-core fiber. The experimental data open new possibilities to achieve higher powers in cladding-pumped BDF sources, which are more cost-effective compared to core-pumped counterparts.
Dual-wavelength channel GHz repetition rate mode-locked VECSEL cavities sourced from a common gain medium
Authors: Tsaoussis Simon P. , Addamane Sadhvikas , Jones R. Jason , Moloney Jerome V.
Published: March 2024

Mode-locked vertical external cavity semiconductor lasers are a unique
class of nonlinear dynamical systems driven far from equilibrium. We
present a novel, to the best of our knowledge, experimental result,
supported by rigorous microscopic simulations, of two coexisting
mode-locked V-cavity configurations sourced by a common gain medium
and operating as independent channels at angle controlled separated
wavelengths. Microscopic simulations support pulses coincident on the
common gain chip extracting photons from a nearby pair of coexisting
kinetic holes burned in the carrier distributions.