bluuebunny/crossref_metadata_2025 huggingface dataset:
Prostate Cancer Disparities in Risk Group at Presentation and Access to Treatment for Asian Americans, Native Hawaiians, and Pacific Islanders: A Study With Disaggregated Ethnic Groups
Authors: Jain Bhav , Ng Kenrick , Santos Patricia Mae G. , Taparra Kekoa , Muralidhar Vinayak , Mahal Brandon A. , Vapiwala Neha , Trinh Quoc-Dien , Nguyen Paul L. , Dee Edward Christopher
Published: October 2021

PURPOSE:

We identified (1) differences in localized prostate cancer (PCa) risk group at presentation and (2) disparities in access to initial treatment for Asian American, Native Hawaiian, and Pacific Islander (AANHPI) men with PCa after controlling for sociodemographic factors.

METHODS:

We assessed all patients in the National Cancer Database with localized PCa with low-, intermediate-, and high-risk disease who identified as Thai, White, Asian Indian, Chinese, Vietnamese, Korean, Japanese, Filipino, Hawaiian, Pacific Islander, Laotian, Pakistani, Kampuchean, and Hmong. Multivariable logistic regression defined adjusted odds ratios (AORs) with 95% CI of (1) presenting at progressively higher risk group and (2) receiving treatment or active surveillance with intermediate- or high-risk disease, adjusting for sociodemographic and clinical factors.

RESULTS:

Among 980,889 men (median age 66 years), all AANHPI subgroups with the exception of Thai (AOR = 0.84 [95% CI, 0.58 to 1.21], P > .05), Asian Indian (AOR = 1.12 [95% CI, 1.00 to 1.25], P > .05), and Pakistani (AOR = 1.34 [95% CI, 0.98 to 1.83], P > .05) men had greater odds of presenting at a progressively higher PCa risk group compared with White patients (Chinese AOR = 1.18 [95% CI, 1.11 to 1.25], P < .001; Japanese AOR = 1.36 [95% CI, 1.26 to 1.47], P < .001; Filipino AOR = 1.37 [95% CI, 1.29 to 1.46], P < .001; Korean AOR = 1.32 [95% CI, 1.18 to 1.48], P < .001; Vietnamese AOR = 1.20 [95% CI, 1.07 to 1.35], P = .002; Laotian AOR = 1.60 [95% CI, 1.08 to 2.36], P = .018; Hmong AOR = 4.07 [95% CI, 1.54 to 10.81], P = .005; Kampuchean AOR = 1.55 [95% CI, 1.03 to 2.34], P = .036; Asian Indian or Pakistani AOR = 1.15 [95% CI, 1.07 to 1.24], P < .001; Native Hawaiians AOR = 1.58 [95% CI, 1.38 to 1.80], P < .001; and Pacific Islanders AOR = 1.58 [95% CI, 1.37 to 1.82], P < .001). Additionally, Japanese Americans (AOR = 1.46 [95% CI, 1.09 to 1.97], P = .013) were more likely to receive treatment compared with White patients.

CONCLUSION:

Our findings suggest that there are differences in PCa risk group at presentation by race or ethnicity among Asian American, Native Hawaiian, and Pacific Islander subgroups and that there exist disparities in treatment patterns. Although AANHPI are often studied as a homogenous group, heterogeneity upon subgroup disaggregation underscores the importance of further study to assess and address barriers to PCa care.
Long Live the Mass Line! Errant Cadres and Post-Disillusionment PRC History
Authors: Smith Aminda
Published: October 2021

The first rule of PRC history might be “Never take the Chinese Communists at their word.” Early observers praised the CCP, but by the 1990s there was broad disillusionment among China scholars who increasingly believed that observable realities contradicted official claims. In the post-disillusionment era, that realization became a methodology; generations of students were trained to look for sources that exposed the truths the Party ostensibly sought to hide. For archival historians this method has produced strange results, because many of the sources used to tell the untold stories of Chinese Communism are the Party's own documents. Even as historians read the state's internal records critically, there is still a tendency to be noticeably uncritical when those documents contain information that seems to vitiate official propaganda. This article explores the unreliable analyses that result when scholars attempt to turn state sources against the state. It further argues that much of the “damning” evidence against the Party actually appeared in official, published sources—but because archival historians often dismiss propaganda as fiction, the scholarship has not traced state claims closely enough to recognize and identify them in classified sources.
Microtubule-dependent subcellular organisation of pluripotent cells
Authors: Hawdon Azelle , Aberkane Asma , Zenker Jennifer
Published: October 2021

With the advancement of cutting-edge live imaging technologies, microtubule remodelling has evolved as an integral regulator for the establishment of distinct differentiated cells. However, despite their fundamental role in cell structure and function, microtubules have received less attention when unravelling the regulatory circuitry of pluripotency. Here, we summarise the role of microtubule organisation and microtubule-dependent events required for the formation of pluripotent cells in vivo by deciphering the process of early embryogenesis: from fertilisation to blastocyst. Furthermore, we highlight current advances in elucidating the significance of specific microtubule arrays in in vitro culture systems of pluripotent stem cells and how the microtubule cytoskeleton serves as a highway for the precise intracellular movement of organelles. This Review provides an informed understanding of the intrinsic role of subcellular architecture of pluripotent cells and accentuates their regenerative potential in combination with innovative light-inducible microtubule techniques.
Talin in mechanotransduction and mechanomemory at a glance
Authors: Goult Benjamin T. , Brown Nicholas H. , Schwartz Martin A.
Published: October 2021

Talins are cytoskeletal linker proteins that consist of an N-terminal head domain, a flexible neck region and a C-terminal rod domain made of 13 helical bundles. The head domain binds integrin β-subunit cytoplasmic tails, which triggers integrin conformational activation to increase affinity for extracellular matrix proteins. The rod domain links to actin filaments inside the cell to transmit mechanical loads and serves as a mechanosensitive signalling hub for the recruitment of many other proteins. The α-helical bundles function as force-dependent switches – proteins that interact with folded bundles are displaced when force induces unfolding, exposing previously cryptic binding sites for other ligands. This leads to the notion of a talin code. In this Cell Science at a Glance article and the accompanying poster, we propose that the multiple switches within the talin rod function to process and store time- and force-dependent mechanical and chemical information.
Dynamic Evaluation Design
Authors: Smolin Alex
Published: October 2021

A principal owns a firm, hires an agent of uncertain productivity, and designs a dynamic policy for evaluating his performance. The agent observes ongoing evaluations and decides when to quit. When not quitting, the agent is paid a wage that is linear in his expected productivity; the principal claims the residual performance. After quitting, the players secure fixed outside options. I show that equilibrium is Pareto efficient. For a broad class of performance technologies, the equilibrium wage deterministically grows with tenure. My analysis suggests that endogenous performance evaluation plays an important role in shaping careers in organizations. (JEL D21, D82, D83, J24, J31, J41, M51)
The Times They Are A-Changing: Experimenting with Dynamic Adverse Selection
Authors: Araujo Felipe A. , Wang Stephanie W. , Wilson Alistair J.
Published: October 2021

We examine a common value dynamic matching environment where adverse selection accrues slowly over time. Theoretical best responses are therefore time varying, and the prior experimental literature suggests that sequential environments might lead to greater understanding of adverse selection in this dynamic setting. However, while a sophisticated minority in our experiment do condition on time and are close to a best response, the majority use a stationary response, even after extended experience. In an environment with persistent uncertainty, our results indicate that sequentiality is insufficient for the large majority of participants to recognize the effects of adverse selection. (JEL C78, C92, D82, D91)
Effects of Copyrights on Science: Evidence from the WWII Book Republication Program
Authors: Biasi Barbara , Moser Petra
Published: October 2021

Copyrights, which establish intellectual property in music, science, and other creative goods, are intended to encourage creativity. Yet, copyrights also raise the cost of accessing existing work—potentially discouraging future innovation. This paper uses an exogenous shift toward weak copyrights (and low access costs) during World War II to examine the potentially adverse effects of copyrights on science. Using two alternative identification strategies, we show that weaker copyrights encouraged the creation of follow-on science, measured by citations. This change is driven by a reduction in access costs, allowing scientists at less affluent institutions to use existing knowledge in new follow-on research. (JEL I23, K11, L82, N42, O34, Z11)
Orchestrating Information Acquisition
Authors: Lu Jingfeng , Ye Lixin , Feng Xin
Published: October 2021

We study how to orchestrate information acquisition in an environment where bidders endowed with original estimates (“types”) about their private values can acquire further information by incurring a cost. We consider both single-round and fully sequential short-listing rules. The optimal single-round shortlisting rule admits the set of most efficient bidders that maximizes expected virtual surplus adjusted by the second-stage signal and information acquisition cost. When shortlisting is fully sequential, at each round, the most efficient remaining bidder is admitted provided that her conditional expected contribution to the virtual surplus is positive. (JEL D44, D82, D83)
Proactive measures to eradicate Malaysia’s poverty in IR4.0 era: a shared prosperity vision
Authors: Darmalinggam Darshana , Kaliannan Maniam , Dorasamy Magiswary
Published: October 2021

Background: In the country’s shared prosperity vision, Malaysia aspires to uplift the bottom 40% household income group (B40) by addressing wealth and income disparities. By 2030, the nation seeks to eradicate poverty through the provision of employment opportunities and career progression plans. A grey area between the nation’s aspirations and actions in practice can be observed because the goals have not been achieved despite numerous efforts aimed at the upliftment of the B40 group. The nation is still way behind its targeted outcomes despite various policies being implemented, which could be attributed to the mismatch between government policies and that of organisational practice. Thus, this study explores the rationale of strategic government intervention in managing B40 talent in the IR4.0 era.

Methods: A general qualitative inquiry method that used 11 semi-structured interviews was carried out with representatives of Malaysia’s policy makers’, training providers, and trainees. All Interview questions centred around measures, importance and outcomes of B40 youth training from a multi-stakeholder perspective. Data were thematically analysed in five stages using NVivo.

Results: Training, which includes IR4.0 era digital skills, is the key to uplifting the B40 youth to eradicate poverty. Proactive measures are imperative in the success of B40 youth training towards poverty eradication.

Conclusions: This study contributes to the existing literature and helps practitioners by addressing the current gap in Malaysia’s aspirations versus organisational practice. Stakeholders should formulate proactive strategies to ensure that the right trainees are matched with the right training providers and government policies. A linkage between government policies and industry requirements needs to be established as opposed to the present discontinuity. A structured training needs analysis should be applied through a collaboration between industries and governments. Then, B40 individuals commonly found in lower-level positions can be pooled into the career pathway towards a shift into M40.
P2P Lending platforms in Malaysia: the awareness among young adults
Authors: Nguyen Lan Thi Phuong , Muthaiyah Saravanan , Sy Malick Ousmane
Published: October 2021

Background - Since 2016, the Securities Commission (SC) in Malaysia has given licenses to only eleven P2P lending platforms. Such lending platforms are expected to disrupt the lending services of traditional lenders in the coming years. However, being still in their infant stages, it is essential to know the extent to which such platforms are made known to potential investors out there. This study examines the extent to which young adults are aware of Malaysia's eleven P2P lending platforms.   

Methods - A sample of 65 undergraduate students majoring in finance and accounting was used for this pilot study. An online questionnaire was designed with three main parts: demographic, financial literacy, and P2P lending awareness.  

Results - Findings show that more than half of respondents in the sample are not aware of P2P lending platforms in Malaysia.  Most of the respondents are financially literate to certain degrees. Those aware of their presence underestimated the potentially high level of their default rates and misunderstood that investor would be fully protected by such platforms when a loan default.  

Conclusions -The study's findings have shed light on the current awareness of P2P lending platforms among Malaysian young adults, potential investors of such platforms in the coming years.
The critical issue of using lead for sustainable massive production of perovskite solar cells: a review of relevant literature
Authors: Maranghi Simone , Parisi Maria Laura , Basosi Riccardo , Sinicropi Adalgisa
Published: October 2021

This work aims to review the most significant studies dealing with the environmental issues of the use of lead in perovskite solar cells (PSCs). A careful discussion and rationalization of the environmental and human health toxicity impacts, evaluated by life cycle assessment and risk assessment studies, is presented. The results of this analysis are prospectively related to the possible future massive production of PSC technology.
Short-term metabolic resistance inductive effect of different agrochemical groups on Anopheles gambiae mosquitoes
Authors: Sadia Christabelle G. , Kouadio France-Paraudie A. , Fodjo Behi K. , Oyou Sebastien K. , Beatrice Adepo-Gourene A. , Koudou Benjamin G. , Mouhamadou Chouaïbou S.
Published: October 2021

Background: In order to assess the impact of the different groups of agricultural pesticides used in Côte d'Ivoire on the increase of mosquitoes resistance to insecticides, the expression profiles of 7 P450 cytochromes and one GSTE2 of Anopheles gambiae involved in mosquito resistance to insecticides were studied. The goal of this study was to determine the effect of short exposure of mosquito larvae to different groups of agricultural pesticides on mosquito resistance.

Methods: Three groups of pesticides were selected: (i) agricultural insecticide solutions, (ii) non-insecticide pesticide solutions (a mixture of herbicides and fungicides), and (iii) a mixture of the first two. A fourth non-pesticide solution was used as a control. Four groups of each stage 2 larvae (strain Kisumu, male and female) were exposed to 20% concentrated solution for 24 hours. Susceptibility tests for dichlorodiphenyltrichloroethane (DDT) and Deltamethrin were carried out on adults aged 2-5 days. Quantitative reverse transcription polymerase chain reaction (RT-qPCR) was performed to quantify the expression of eight metabolic genes involved in mosquito resistance to insecticides. 

Results: Susceptibility to DDT showed a similar increase in the time required to knock down 50% of mosquitoes (kdt50) in l colonies exposed to insecticides and non-insecticides compared to the control colony. As for deltamethrin, kdt50 was higher in the colonies exposed to insecticides and the pesticide mixture compared to the colony exposed to non-insecticides. Of all the genes studied in all colonies, except for CYP6P1 induced only in the colony consisting of the pesticide mixture, no genes were induced.

Conclusions: This study confirmed that induction is influenced by the duration, the concentration of the solution and the type of xenobiotic used as an inducer. The overexpression of CYP6P1 confirmed the inductive effect that a short exposure of mosquito larvae to agricultural pesticides could have.
Patient outcomes and prognostic factors associated with colonic perforation surgery: a retrospective study
Authors: Lee Do-bin , Shin Seonhui , Yang Chun-Seok
Published: October 2021

Background: Despite advances in surgery and intensive perioperative care, fecal peritonitis secondary to colonic perforation is associated with high rates of morbidity and mortality. This study was performed to review the outcomes of patients who underwent colonic perforation surgery and to evaluate the prognostic factors associated with mortality. Methods: A retrospective analysis was performed on 224 consecutive patients who underwent emergency colonic perforation surgery between January 2008 and May 2019. We divided the patients into survivor and non-survivor groups and compared their surgical outcomes.Results: The most common cause of colon perforation was malignancy in 54 patients (24.1%), followed by iatrogenic perforation in 41 (18.3%), stercoral perforation in 39 (17.4%), and diverticulitis in 37 (16.5%). The sigmoid colon (n=124, 55.4%) was the most common location of perforation, followed by the ascending colon, rectum, and cecum. Forty-five patients (20.1%) died within 1 month after surgery. Comparing the 179 survivors with the 45 non-survivors, the patient characteristics associated with mortality were advanced age, low systolic blood pressure, tachycardia, organ failure, high C-reactive protein, high creatinine, prolonged prothrombin time, and high lactate level. The presence of free or feculent fluid, diffuse peritonitis, and right-sided perforation were associated with mortality. In multivariate analysis, advanced age, organ failure, right-sided perforation, and diffuse peritonitis independently predicted mortality within 1 month after surgery.Conclusion: Age and organ failure were prognostic factors for mortality associated with colon perforation. Furthermore, right-sided perforation and diffuse peritonitis demonstrated a significant association with patient mortality.
Recourse in Kidney Exchange Programs
Authors: Smeulders Bart , Bartier Valentin , Crama Yves , Spieksma Frits C. R.
Published: October 2021

We introduce the problem of selecting patient-donor pairs in a kidney exchange program to undergo a crossmatch test, and we model this selection problem as a two-stage stochastic integer programming problem. The optimal solutions of this new formulation yield a larger expected number of realized transplants than previous approaches based on internal recourse or subset recourse. We settle the computational complexity of the selection problem by showing that it remains NP-hard even for maximum cycle length equal to two. Furthermore, we investigate to what extent different algorithmic approaches, including one based on Benders decomposition, are able to solve instances of the model. We empirically investigate the computational efficiency of this approach by solving randomly generated instances and study the corresponding running times as a function of maximum cycle length, and of the presence of nondirected donors.

Summary of Contribution: This paper deals with an important and very complex issue linked to the optimization of transplant matchings in kidney exchange programs, namely, the inherent uncertainty in the assessment of compatibility between donors and recipients of transplants. Although this issue has previously received some attention in the optimization literature, most attempts to date have focused on applying recourse to solutions selected within restricted spaces. The present paper explicitly formulates the maximization of the expected number of transplants as a two-stage stochastic integer programming problem. The formulation turns out to be computationally difficulty, both from a theoretical and from a numerical perspective. Different algorithmic approaches are proposed and tested experimentally for its solution. The quality of the kidney exchanges produced by these algorithms compares favorably with that of earlier models.
BiGRU-Attention Based Cow Behavior Classification Using Video Data for Precision Livestock Farming
Authors: Guo Yangyang , Qiao Yongliang , Sukkarieh Salah , Chai Lilong , He Dongjian
Published: October 2021

Highlights

BiGRU-attention based cow behavior classification was proposed.

Key spatial-temporal features were captured for behavior representation.

BiGRU-attention achieved >82% classification accuracy on calf and adult cow datasets.

The proposed method could be used for similar animal behavior classification.

Abstract. Animal behavior consists of time series activities, which can reflect animals’ health and welfare status. Monitoring and classifying animal behavior facilitates management decisions to optimize animal performance, welfare, and environmental outcomes. In recent years, deep learning methods have been applied to monitor animal behavior worldwide. To achieve high behavior classification accuracy, a BiGRU-attention based method is proposed in this article to classify some common behaviors, such as exploring, feeding, grooming, standing, and walking. In our work, (1) Inception-V3 was first applied to extract convolutional neural network (CNN) features for each image frame in videos, (2) bidirectional gated recurrent unit (BiGRU) was used to further extract spatial-temporal features, (3) an attention mechanism was deployed to allocate weights to each of the extracted spatial-temporal features according to feature similarity, and (4) the weighted spatial-temporal features were fed to a Softmax layer for behavior classification. Experiments were conducted on two datasets (i.e., calf and adult cow), and the proposed method achieved 82.35% and 82.26% classification accuracy on the calf and adult cow datasets, respectively. In addition, in comparison with other methods, the proposed BiGRU-attention method outperformed long short-term memory (LSTM), bidirectional LSTM (BiLSTM), and BiGRU. Overall, the proposed BiGRU-attention method can capture key spatial-temporal features to significantly improve animal behavior classification, which is favorable for automatic behavior classification in precision livestock farming. Keywords: BiGRU, Cow behavior, Deep learning, LSTM, Precision livestock farming.
Natural History of Rotator Cuff Tears
Authors: Willems W. Jaap
Published: October 2021

Rotator cuff tears are a frequent phenomenon with an increasing incidence when the patient gets older. A considerable number of tears remain asymptomatic during a lifetime. However, still, a substantial number of asymptomatic tears become symptomatic. There is, at present evolving evidence that surgical treatment of small to medium-sized tears does better than conservative treatment, even after a long term follow-up. A treatment algorithm is suggested to help the clinician in decision making, where tear size and age are important factors in the prognosis of surgical treatment.
Keywords: Rotator cuff; Ruptures; Natural historyf tears; Partial rotator cuff tears; Subscapularis tears; Geometric Classification; Arthroscopic Classification; Rotator cuff retraction; Rotator cuff tendon quality; Prognosis for Rotator Cuff tears.
Utilization of Robotic Arm Assistance for Revision of Primary Total Knee Arthroplasty: A Case Report
Authors: Steelman Kevin , Carlson Kyle , Ketner Andrew
Published: October 2021

Introduction: With increasing numbers of knee arthroplasty procedures being performed, revision total knee arthroplasty (TKA) remains a challenge to orthopedic surgeons. The use of robotics in primary joint arthroplasty is also increasing due to better technology and surgeon familiarity. Robotic arms have the ability to execute bone cuts within 1 mm of a preoperative plan, can measure soft tissue gap tension, and can plan femoral and tibial augments and rotation. The use of robotic arm assistance for revision TKA, however, has not been documented in the literature.

Case Report: We present a case describing a novel technique in which the Mako robot (Stryker, Ft. Lauderdale, FL) was utilized for revision of a failed primary TKA secondary to aseptic loosening. The patient is a 68-year-old Caucasian male who underwent right revision TKA with robotic assistance. Stryker Triathlon TS implants were utilized with the use of both femoral and tibial cones and medial and lateral posterior femoral augments. He had satisfactory component alignment based on postoperative radiographs, and excellent clinical outcomes 6 months postoperatively.

Conclusion: The use of robotic arm assistance in revision TKA for failed primary TKA is a novel technique and resulted in excellent operative outcomes in this case. Further study should be done to confirm its use in revision TKA.

Keywords: Total knee arthroplasty, robotic, revision, total knee arthroplasty.
Patellofemoral Joint Auto-fusion after Patella Tendon Repair: A Case Report
Authors: Herron Thomas , Seaman Travis , Feighan John
Published: October 2021

Introduction: Post-traumatic patellofemoral auto fusion is poorly described in the literature and its etiology may be multifactorial. Management options are not well published and this case report addresses a rare and complex case of patellofemoral autofusion after a patellar tendon repair with a description of our surgical approach and ultimately improvement in patient outcome and satisfaction.

Case Presentation: A 59-year-old African American female suffered an acute traumatic patellar tendon rupture that was treated with a primary repair that resulted in sequelae leading to a subsequent open procedure revealing an osseous bridge between the patella and trochlea. After osteotomy of this bridge, the patient’s range of motion improved.

Conclusion: For the appropriate management of arthrofibrosis surgeons should focus on modifiable risk factors including close follow-up with patients, patient expectation management, and consider surgical intervention such as techniques described below in recalcitrant cases to evaluate for post-traumatic sequelae including bone bridge formation.

Keywords: Patella tendon, arthrofibrosis, tendon repair.
Scurvy Masquerading as Septic Arthritis in a Case of Cerebral Palsy
Authors: Jain Deepak S , Agrawal Tushar , Malviya Parimal K
Published: October 2021

Introduction: Scurvy is a rarely seen in pediatric patients nowadays, seen more in those with developmental delay, autism or those who are severely malnourished. Epiphyseal separations are known to occur in scurvy, but only a few such cases have been reported in children with cerebral palsy. The diagnosis is often misleading since other morbidities as trauma, malignancies, coagulopathies, septic arthritis, osteomyelitis, or rheumatologic disorders are often considered at first. We report the case of 4-year-old female child with cerebral palsy in whom the initial concern was septic arthritis/osteomyelitis based upon clinical presentation, ultrasonic and magnetic resonance imaging, led to a surgery revealing subperiosteal hematomas.

Case Report: A 4-year-old girl was admitted in the pediatrics department for fever and bilateral knee joint pain for 3 days. She was a diagnosed case of with cerebral palsy, psyco-developmental delay, and epileptogenic disorder put under valproic acid. She was toxic and febrile. Within 4 h after admission, both knees developed tense shiny intense swelling associated with pain, redness, and local rise of temperature with limited active range of motion. Near-complete passive range of motion was noted. There were no abnormal findings on the rest of the musculoskeletal examination. Aspiration of the knee revealed subperiosteal hematoma diagnostic of scurvy.

Conclusion: Scurvy is exceedingly rare in children nowadays; however, its presentation among risky populations should not be forgotten. Musculoskeletal revelations, mostly subperiosteal hematoma, are the main manifestation of scurvy in the pediatric population. Scurvy as a differential diagnosis for trauma, osteomyelitis, septic arthritis will always be a bane for orthopedic surgeons. A heightened awareness is needed to avoid unnecessary surgery, unnecessary tests, and procedures and to be able to start treatment for a potentially fatal but easily curable disease.

Keywords: Scurvy, cereb
The influence of deposit-feeding organisms on sediment stability and community trophic structure
Authors: Rhoads Donald C. , Young David K.
Published: October 2021

Deposit-feeding and suspension-feeding benthos in Buzzards Bay, Massachusetts, show marked spatial separation; suspension feeders are largely confined to sandy or firm mud bottoms while deposit feeders attain high densities on soft muddy substrata. Food source and bottom stability have
been investigated as potential factors effecting this trophic-group separation. Between October 4, 1967 and August 22, 1969, observations were made at 11 stations in Buzzards Bay, Massachusetts, along two widely separated transects over bottoms ranging in texture from silt to fine and medium
sand. Water depths at these stations ranged from 3 m to 20 m. Scuba divers made many of the field observations and collected most of the samples. This study included sampling of benthic macrofauna, taking bottom photographs, analyzing sedimentary structures, texture, organic content and water
content of the sediments, and measuring both water currents and suspended sediment above the bottom. Laboratory experiments were also carried out to determine differential resuspension between burrowed and unburrowed muds. Intensive reworking of the upper few centimeters of a mud bottom by
deposit feeders produces a fluid fecal-rich surface that is easily resuspended by low-velocity tidal currents. We suggest that the physical instability of this fecal surface tends to: (i) clog the filtering structures of suspension-feeding organisms, (ii) bury newly settled larvae or discourage
the settling of suspension-feeding larvae, and (iii) prevent sessile epifauna from attaching to an unstable mud bottom. Thus suspension feeders are unable to successfully populate all areas of the bottom where a suspended food source is available, especially in areas where mud bottoms are
intensively reworked by deposit feeders. Modification of the benthic environment by deposit feeders, resulting in the exclusion of many suspension feeders and sessile epifauna, is an example of trophic group amensalism. This biotic relationship appears to be important in shaping trophic-group
distributions in embayments and basins on continental shelves.
Wavelength-tunable deep-ultraviolet thin-film filter: design and experimental demonstration
Authors: Zhu Xingyue , Yu Kaixiong , Zhu Xiaofan , Wu Chi
Published: October 2021

A deep-ultraviolet (DUV) narrowband tunable filter with a central wavelength of 225.0 nm is designed, fabricated, and demonstrated experimentally. The simulation results showed a transmittance of about 42.1% at 225.0 nm and a full width at half-maximum (FWHM) of

∼

1.2

n
m

. The experimental results for normal incidence light revealed a corresponding central wavelength of 225.0 nm, a transmittance of 27.7%, and a FWHM of 1.9 nm. By changing the incident angle, the central wavelength can be tuned from 225.0 to 224.5 nm. This DUV narrowband tunable filter has been shown to demonstrate good performance and has broad applicability.
Multiplexing temperature-compensated open-cavity Fabry–Perot sensors at a fiber tip
Authors: Pfalzgraf Ivonne , Suntsov Sergiy , Kip Detlef
Published: October 2021

We investigate multiplexing of four highly sensitive Fabry–Perot (FP) microresonators at the tip of a single-mode optical fiber for refractive index (RI) measurements with simultaneous temperature compensation. The individual sensing elements for RI or temperature consist of either open-cavity FP resonators or solid fiber core regions fabricated by diamond-blade dicing of single-mode optical fibers, respectively. The reflectivity of the open resonators is further enhanced by matched dielectric coatings. At the same time, the solid core resonators formed by the fiber pieces between the open cavities are used as thermometers. This allows immediate compensation for temperature cross-sensitivity during RI measurements. The general performance of the sensor is demonstrated by measuring the RI of sucrose solutions, where we use phase tracking of the characteristic Fourier transform components of the backreflected optical spectrum for evaluation. The temperature sensitivity is on average

20

±

/

∘

C

with an accuracy of 0.01°C, fully sufficient for biomedical applications. Meanwhile, the four RI sensing (open) cavities show high sensitivity of approximately 1160 nm/RIU. Due to the compact size of the sensor, small spatial inhomogeneities of RI can be accurately detected. If the cavities are additionally filled with molecularly imprinted polymers or coated with thin functional layers, they could also be used for the detection of trace substances in biomedical laboratory-on-a-fiber applications.
Strain distribution characteristics of sensing fiber and influence on sensitivity of a fiber-optic disk accelerometer
Authors: Tian Shuaifei , Zhu Haibo , An Ran , Tang Yiping , Yuan Yonggui , Dang Fanyang , Zhu Yunlong , Wang Xiaozhang , Yang Jun , Wang Yuncai , Qin Yuwen
Published: October 2021

In a fiber-optic disk accelerometer, the strain distribution of sensing fiber is crucial for the improvement of sensitivity. The distribution characteristics of axial and radial strain in the sensing fiber are analyzed by the finite-element method, and the influence of strain distribution on the sensitivity of accelerometer is studied. Sensors with different outer radii of sensing fiber coils are designed and manufactured, and their performance is tested. The resonant frequencies are greater than 200 Hz, and the sensitivity increases as the outer radius of the sensing fiber coil increases. The dynamic range of the sensor with maximum sensitivity is 145.8 dB@100 Hz, and the transverse cross talk is 32.5 dB. Among the sensing fiber strain calculation methods we tested to predict the value of sensitivity, using the strain of sensing fiber directly obtained by the finite-element analysis method shows the smallest error with experimental results (within 7%). It is concluded that in the optical fiber strain disk, the absolute values of axial strain and radial strain of sensing fiber decrease with the increase of disk radius, while the signs of axial strain and radial strain of the ipsilateral sensing fiber are opposite and remain unchanged. The sensitivity can be further improved by optimizing the inner and outer radius of the sensing fiber coils, which is very important for the research and design of high-sensitivity fiber-optic accelerometers.
Monitoring particulate composition changes during the flocculation process using polarized light scattering
Authors: Chen Yan , Liao Ran , Li Jiajin , Zhou Hu , Wang Hongjian , Zhuo Zepeng , Wang Qiang , Yan Chongling , Ma Hui
Published: October 2021

Monitoring the particulate composition changes during the flocculation process is still challenging for the research community. We use an experimental setup based on polarized light scattering to measure the polarization states of the scattered light of the individual particles. We build a classifier based on the support vector machine and feed it with the measured parameters. Results show that the classifier can effectively classify the particulate compositions, such as the sediment particles, flocculants, and flocs, which can be used to monitor the particulate composition changes during the flocculation process. Discussions on the intensity and polarization parameters find that the polarization parameters play a vital role in the classification of the particulate compositions in the flocculation suspensions. Additionally, the further analysis of the experimental data and the related simulations show that the degree of polarization can be an indicator of the flocculation process. We prove that the method based on polarized light scattering may be a potential in situ monitoring tool in the future for the study of the flocculation process.
Self-calibration method for rotating Risley prism main sections based on chromatic dispersion characteristics of the Fourier spectrum
Authors: Li Anhu , Zhou Zhengyang
Published: October 2021

To address the main section misalignment of rotating Risley prisms in a camera imaging system, a zero calibration method for a Risley prism main section is proposed according to the dispersion characteristics of the prisms–camera imaging. The principal component analysis method and the Radon transform method are combined to establish an effective mapping relationship between the prism main section positions and the prismatic dispersion characteristics using the camera dispersion image as references. The estimation of the dispersion direction was realized by referring to the motion blur estimation method and verified by experiment. As a result, the target-free self-calibration of the prism main sections in the camera coordinate system can be carried out under a prisms–camera intact assembly mode.
Backscatter multiple wavelength digital holography for color micro-particle imaging
Authors: Giri Ramesh , Berg Matthew J.
Published: October 2021

This work applies digital holography to image stationary
micro-particles in color. The approach involves a Michelson
interferometer to mix reference light with the weak intensity light
backscattered from a distribution of particles. To enable color
images, three wavelengths are used, 430, 532, and 633 nm, as primary
light sources. Three separate backscattered holograms are recorded
simultaneously, one for each wavelength, which are resolved without
spectral cross talk using a three-CMOS prism sensor. Fresnel
diffraction theory is used to render monochrome images from each
hologram. The images are then combined via additive color mixing with
red, green, and blue as the primary colors. The result is a color
image similar in appearance to that obtained with a conventional
microscope in white-light epi-illumination mode. A variety of colored
polyethylene micro-spheres and nonspherical dust particles demonstrate
the feasibility of the approach and illustrate the effect of simple
speckle-noise suppression and white balance methods. Finally, a
chromaticity analysis is applied that is capable of differentiating
particles of different colors in a quantitative and objective
manner.
Confocal fluorescence microscopy with high-NA diffractive lens arrays
Authors: Li Zheng , Taphanel Miro , Längle Thomas , Beyerer Jürgen
Published: October 2021

Traditionally, there is a trade-off between the numerical aperture and
field of view for a microscope objective. Diffractive lens arrays
(DLAs) with overlapping apertures are used to overcome such a problem.
A spot array with an NA up to 0.83 and a pitch of 75 µm is produced by
the proposed DLA at a wavelength of 488 nm. By measurement of the
fluorescence beads, the DLA-based confocal setup shows the capability
of high-resolution measurement over an area of

3

m
m

×
3

m
m

with a

2.5
×
0.07

N
A

objective. Further, the proposed
fluorescence microscope is insensitive to optical aberrations, which
has been demonstrated by imaging with a simple doublet lens.
Effective light trapping in c-Si thin-film solar cells with a dual-layer split grating
Authors: Chen Ke , Zheng Nianhong , Wu Sheng , He Jinyang , Yu Yingchun , Zheng Hongmei
Published: October 2021

We propose a dual-layer split nanograting structure in crystalline silicon thin-film solar cells (TFSCs). The split nanograting is designed by introducing two partitioning factors and split times. By employing the finite-difference time-domain method, the light trapping performance and relevant parameters of TFSCs are analyzed and optimized. Numerical computation of optical and electrical simulation shows that the optimal dual-layer split nanograting structure has demonstrated great enhanced light absorption compared with the planar structure. Enhancement of the light trapping effect is associated with light coupling to waveguide modes. The short-circuit current density is reached at

21.66

m
A

/

c
m

2

with an improvement of 54.6% over the planar structure. All results provide a parting thought for the design of TFSC grating structures.
Ultrasound liquid crystal lens with a variable focus in the radial direction for image stabilization
Authors: Onaka Jessica , Iwase Takahiro , Emoto Akira , Koyama Daisuke , Matsukawa Mami
Published: October 2021

New technologies for adaptive optics are becoming increasingly important for miniature devices such as cell-phone cameras. In particular, motion-free autofocusing and optical image stabilization require sophisticated approaches for alternative lens architectures, materials, and processing to replace multiple solid elements. We discuss a new method, to the best of our knowledge, that provides image stabilization via an annular piezoelectric ceramic that uses ultrasound to drive a liquid crystal layer sandwiched between two circular glass substrates. The piezoelectric ceramic is divided into four quadrants that are independently driven with sinusoidal voltages at the resonant frequency of the lens. The technique is based on ultrasound vibrations with a suitable driving scheme. The lens configuration was modeled via finite-element analysis. Various combinations of the four-channel ultrasound transducer can be used to define the focal point of the liquid crystal lens. Clear optical images could be obtained with the lens. By using two-dimensional fast Fourier transforms, the focal point position was defined and shifted in the radial direction.
Automatic correction of the initial rotation angle error improves 3D reconstruction in endoscopic airway optical coherence tomography
Authors: Qi Li , Zhuang Zhijian , Zhang Shuangyang , Huang Shixian , Feng Qianjin , Chen Wufan
Published: October 2021

Endoscopic airway optical coherence tomography (OCT) is an advanced imaging modality capable of capturing the internal anatomy and geometry of the airway. Due to fiber-optic catheter bending and friction, the rotation speed of the endoscopic probe is usually non-uniform: at each B-scan image, the initial rotation angle of the probe is easily misaligned with that of the previous slices. During the pullback operation, this initial rotation angle error (IRAE) will be accumulated and will result in distortion and deformation of the reconstructed 3D airway structure. Previous attempts to correct this error were mainly manual corrections, which are time-consuming and suffered from observer variation. In this paper, we present a method to correct the IRAE for anatomically improved visualization of the airway. Our method derived the rotation angular difference of adjacent B-scans by measuring their contour similarity and then tracks the IRAE by formulating its continuous drift as a graph-based problem. The algorithm was tested on a simulated airway contour dataset, and also on experimental datasets acquired by two different long range endoscopic airway OCT platforms. Effective and smooth compensation of the frame-by-frame initial angle difference was achieved. Our method has real-time capability and thus has the potential to improve clinical imaging efficiency.
Deep learning-based method for the continuous detection of heart rate in signals from a multi-fiber Bragg grating sensor compatible with magnetic resonance imaging
Authors: Krej Mariusz , Osuch Tomasz , Anuszkiewicz Alicja , Stopinski Stanisław , Anders Krzysztof , Matuk Krzysztof , Weigl Andrzej , Tarasow Eugeniusz , Piramidowicz Ryszard , Dziuda Lukasz
Published: October 2021

A method for the continuous detection of heart rate (HR) in signals acquired from patients using a sensor mat comprising a nine-element array of fiber Bragg gratings during routine magnetic resonance imaging (MRI) procedures is proposed. The method is based on a deep learning neural network model, which learned from signals acquired from 153 MRI patients. In addition, signals from 343 MRI patients were used for result verification. The proposed method provides automatic continuous extraction of HR with the root mean square error of 2.67 bpm, and the limits of agreement were -4.98–5.45 bpm relative to the reference HR.
Extended focal depth Fourier domain optical coherence microscopy with a Bessel-beam – LP02 mode – from a higher order mode fiber
Authors: Sen Dipankar , Classen Anton , Fernández Alma , Grüner-Nielsen Lars , Gibbs Holly C. , Esmaeili Shahriar , Hemmer Philip , Baltuska Andrius , Sokolov Alexei V. , Leitgeb Rainer A. , Verhoef Aart J.
Published: October 2021

We present a robust fiber-based setup for Bessel-like beam extended depth-of-focus Fourier-domain optical coherence microscopy, where the Bessel-like beam is generated in a higher order mode fiber module. In this module a stable guided LP02 core mode is selectively excited by a long period grating written in the higher order mode fiber. Imaging performance of this system in terms of lateral resolution and depth of focus was analyzed using samples of suspended microbeads and compared to the case where illumination is provided by the fundamental LP01 mode of a single mode fiber. Illumination with the LP02 mode allowed for a lateral resolution down to 2.5 µm as compared to 4.5 µm achieved with the LP01 mode of the single mode fiber. A three-fold enhancement of the depth of focus compared to a Gaussian beam with equally tight focus is achieved with the LP02 mode. Analysis of the theoretical lateral point spread functions for the case of LP01 and LP02 illumination agrees well with the experimental data. As the design space of waveguides and long-period gratings allows for further optimization of the beam parameters of the generated Bessel-like beams in an all-fiber module, this approach offers a robust and yet flexible alternative to free-space optics approaches or the use of conical fiber tips.
Ruled surfaces generated by Risley prism pointers: I. Pointing accuracy evaluation and enhancement based on a structural analysis of the scan field inside the pointer
Authors: Li Yajun
Published: October 2021

Based on the elementary concept of ruled surfaces, a new method
relating to a structural analysis of the scan field distributed over
the interior of the Risley prisms is proposed that opens the way to a
re-examination of the pointing accuracy that predicted the existing
noniterative solution of the Risley prism pointers for precision
tracking of targets [Li, J. Opt. Soc. Am. A 28,
667 (2011)JOAOD60740-323210.1364/JOSAA.28.000667 and Li,
Appl. Opt.
50, 4302 (2011)APOPAI0003-693510.1364/AO.50.004302].
After taking the thickness and the air gap of the two prisms into
consideration, the refined version of the closed-form analytic
solution is obtained, which predicts the correct results for detecting
and tracking targets traversing across both the near and far zones of
the beam-steering field in front of the pointer if the linear size of
the target, the diameter of the laser beam, or their combination is
greater than a small fraction of the central thickness of the prism.
For very tiny targets, a method for pointing accuracy enhancement is
proposed based on tracking a virtual target.