bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors associated with knowledge and awareness of stroke among the Lebanese population: A cross-sectional study
Authors: Malaeb Diana , Dia Nada , Haddad Chadia , Hallit Souheil , Sacre Hala , Barakat Muna , Mansour Sara , Salameh Pascale , Hosseini Hassan
Published: July 2022

Background: Evaluation of the knowledge about stroke in the general population is extremely vital as it prevents stroke development, limits complications, and achieves better quality of life.  We assume that the general Lebanese population lacks awareness about stroke and its associated complications. This study aims to evaluate stroke knowledge and determine the factors associated with stroke awareness among the general Lebanese population.

Methods: This cross-sectional study assessed respondents’ sociodemographic characteristics and the identification of risk factors, warning signs, stroke consequences, and early response to stroke symptoms. A total of 551 Lebanese adults without a history of stroke filled in an online self-reported questionnaire publicly shared on social applications. Logistic regression analysis was performed to identify the factors associated with poor knowledge of stroke. 

Results: Among the 551 participants enrolled, 403 (74.2%) were females and 312 (56.7%) were under 30 years of age. Females compared to males and employed compared to unemployed had significantly higher odds of identifying at least one risk factor (OR=4.3 [95%CI=1.1;16.8] and 6 [95%CI=1.2;29.6], respectively). Also, when compared to unemployed, employed participants had significantly higher odds of recognizing at least one of the early stroke symptoms (OR=3.3 [95%CI=1.2;8.9]) and identifying at least one of the stroke consequences (OR=5.3 [95%CI=1.1;25.9]). Reaching a university level of education compared to a school level was associated with significantly higher odds (OR=2.3 [95%CI=1.1;4.8]) of taking a patient to a hospital.

Conclusion: Well-educated, employed, and female participants were more knowledgeable about stroke. Tailored interventions focusing on individuals with inadequate stroke literacy are needed. Further studies, more representative of the general Lebanese population with a larger sample size, are necessary to confirm our findings.
Heatmaps and consensus clustering for ego network exploration
Authors: Boileau Philippe , Kakinami Lisa , Barnett Tracie , Henderson Mélanie , Popovic Lea
Published: July 2022

Background: Researchers need visualization methods (using statistical and interactive techniques) to efficiently perform quality assessments and glean insights from their data. Data on networks can particularly benefit from more advanced techniques since typical visualization methods, such as node-link diagrams, can be difficult to interpret. We use heatmaps and consensus clustering on network data and show they can be combined to easily and efficiently explore nonparametric relationships among the variables and networks that comprise an ego network data set.

Methods: We used ego network data from the Québec Adipose and Lifestyle Investigation in Youth (QUALITY) cohort used to evaluate this method. The data consists of 35 networks centered on individuals (egos), each containing a maximum of 10 nodes (alters). These networks are described through 41 variables: 11 describing the ego (e.g. fat mass percentage), 18 describing the alters (e.g. frequency of physical activity) and 12 describing the network structure (e.g. degree).

Results: Four stable clusters were detected. Cluster one consisted of variables relating to the interconnectivity of the ego networks and the locations of interaction, cluster two consisted of the ego’s age, cluster three contained lifestyle variables and obesity outcomes and cluster four was comprised of variables measuring alter importance and diet.

Conclusions: This exploratory method using heatmaps and consensus clustering on network data identified several important associations among variables describing the alters’ lifestyle habits and the egos’ obesity outcomes. Their relevance has been identified by studies on the effect of social networks on childhood obesity.
Analysis of the influence of asset allocation policy, investment manager performance, and risk level on the performance of Sharia money market mutual funds in Indonesia
Authors: Firli Anisah , Rismayani Risris , Jannah Dinna Miftahul
Published: July 2022

Background: Islamic money market mutual funds have become an alternative to conventional investment instruments. This research has novelty in determining the variables of mutual fund performance by combining risk and return factors, asset allocation policy variables, and investment manager performance, which have a high impact on the return and risk level in reducing the risk of loss on investment. In addition, this research was conducted on the performance of Islamic money market mutual funds that have not been studied before. 

Methods: This research uses data on Islamic money market mutual funds registered with the Financial Services Authority in Indonesia. The performance of Islamic money market mutual funds was calculated using the Sharpe Method and tested using multiple regression analysis. 

Results: The results showed that the asset allocation policy, investment manager performance, and the level of risk simultaneously have a significant effect on the performance of Islamic money market mutual funds in Indonesia; however, partially, there is no significant effect between (1) the asset allocation policy on the performance of Islamic money market mutual funds in Indonesia: (2) investment manager performance on the performance of Islamic money market mutual funds in Indonesia, and (3) the level of risk on the performance of Islamic money market mutual funds in Indonesia.  

Conclusions: The results indicated that optimization of returns and risks was needed by considering the composition of asset allocation, choosing the right investment manager, and conducting a good risk level analysis to obtain optimal Islamic money market mutual fund performance.
Case Report: Nasopharyngeal carcinoma has metastasis to the orbit, consequences in anaemia: A paediatric unusual case of Bangladesh.
Authors: Amin Mohammad Ashraful , Nahin Sabrina , Bonna Atia Sharmin , Hawlader Mohammad Delwer Hossain
Published: July 2022

Background: Although nasopharyngeal carcinoma (NPC) has a significant risk of spreading to other parts of the body early, orbital and ocular surrounding tissues metastases are uncommon.

Case Report: This paper described a 16-year-old patient diagnosed with a locally advanced NPC and ocular metastasis and was treated with neoadjuvant chemotherapy treatment. One of the rare early presentations is orbital metastases with vision problems.

Discussion: Orbital metastases in children are considerably more uncommon. Cachexia and malnutrition are prevalent problems in people with cancer, affecting life and longevity. Anaemia is a severe issue for nasopharyngeal cancer patients undergoing chemotherapy or radiotherapy.

Conclusion: Orbital metastases frequently arise in advanced stages of the disease and in the scenario of many metastases the persistence of therapy and the nasopharyngeal cancer patient's standard of living is linked to the occurrence of anaemia. In addition, to predict the prognosis of individuals with NPC, pretreatment laboratory profiles should be evaluated.
Effect of natural products use prior to infection with COVID-19 on disease severity and hospitalization: A self-reported cross-sectional survey study
Authors: Nimer Refat M. , Khabour Omar F. , Swedan Samer F. , Kofahi Hassan M.
Published: July 2022

Background: Managing coronavirus disease 2019 (COVID-19) using available resources is essential to reduce the health burden of disease. The severity of COVID-19 is affected by nutritional status. In this study the effect of natural product use prior to infection with COVID-19 on disease severity and hospitalization was explored.

Methods: This was a cross-sectional study. Between March and July 2021, a self-administered survey was conducted in Jordan. Individuals who recovered from COVID-19 and were ≥18 years old were the study population. Study measures included the use of natural products, COVID-19 severity, and hospitalization status. A multivariate regression model was used for statistical analysis.

Results: The mean age (mean ± SD) of the study sample (n=2,148) was 40.25 ± 15.58 years old. Multivariate logistic regression showed that the regular intake of carnation (OR [0.56], CI [0.37–0.85]), onion (OR [0.69], CI [0.52–0.92]), lemon (OR [0.68], CI [0.51–0.90]), and citrus fruits (OR [0.66], CI [0.50–0.89]) before infection were associated with a substantial reduction in COVID-19 severity (P<0.01). Also, the consumption of carnation (OR [0.55], CI [0.34–0.88]), lemon (OR [0.57], CI [0.42–0.78]), and citrus fruits (OR [0.61], CI [0.44–0.84]) were associated with a significant decrease in the frequency of COVID-19-induced hospitalization (P<0.01).

Conclusions: Regular consumption of carnation, lemon, and citrus fruits before infection was associated with better outcomes for COVID-19. Studies on other populations are required to confirm these findings.
vcferr: Development, validation, and application of a single nucleotide polymorphism genotyping error simulation framework
Authors: Nagraj V.P. , Scholz Matthew , Jessa Shakeel , Ge Jianye , Woerner August E. , Huang Meng , Budowle Bruce , Turner Stephen D.
Published: July 2022

Motivation: Genotyping error can impact downstream single nucleotide polymorphism (SNP)-based analyses. Simulating various modes and levels of error can help investigators better understand potential biases caused by miscalled genotypes.

Methods: We have developed and validated vcferr, a tool to probabilistically simulate genotyping error and missingness in variant call format (VCF) files. We demonstrate how vcferr could be used to address a research question by introducing varying levels of error of different type into a sample in a simulated pedigree, and assessed how kinship analysis degrades as a function of the kind and type of error.

Software availability: vcferr is available for installation via PyPi (https://pypi.org/project/vcferr/) or conda (https://anaconda.org/bioconda/vcferr). The software is released under the MIT license with source code available on GitHub (https://github.com/signaturescience/vcferr)
The use of 3d printing technology in the development of a prosthetic thumb
Authors: Rezmer Jakub , Wasilewska Inga , Świątek Łukasz
Published: July 2022

Introduction:
Over the years, the popularisation of 3D printing technology created new possibilities for developing customized and cheap prosthetics in a shorter time than time-consuming and expensive conventional methods. With the available software and knowledge, there are limitless possibilities for tailoring every prosthetic exclusively to the patient when keeping the costs reasonably low.
Objective:
The objective of the study was to research, review and compare data available on PubMed about the use of 3D printing in the development of a prosthetic thumb.
A brief description of the state of knowledge:
Conventional methods of prosthetic manufacture require a skilled professional prosthetist, a lot of time, and the costs from 4000-8000$ for a body-powered one, to 25000-50000$ for an externally powered one. That could be a major financial barrier for a patient. The 3D printing technology development over the last 15 years provided a fast and cheap method of manufacture for low-batch prosthetics, including thumb prosthetics, while being able to easily alter the project to customize it to the patient’s needs.
Conclusions:
There is a possibility to create fully functioning and durable thumb prosthetics with 3D printing technology. However, we need more research to provide a universal and fully customizable one to meet every patient's needs.
Advances in osteosynthesis - a basic overview of modern fixation materials
Authors: Kozioł Maciej , Piech Piotr , Wokurka Wojciech , Maciejewski Ryszard
Published: July 2022

The dynamic development of trauma-orthopedic surgery and accompanying material technology has led in recent years to the need for close cooperation between researchers in these fields. In a short time, thanks to the cooperation of engineers and doctors, the general approach to the method of bone anastomosis has changed significantly. The need to optimize the effects of treatment, i.e. to quickly recovery, reduce the number of postoperative complications, reduce the number of reoperations, and reduce the costs of procedures and treatment used has resulted in the development of many new technologies that have set trends in modern traumatology. The widespread use of LCP (Locking compression plate) and locking screws, the development of polymers and biopolymers with a modified chemical structure, a significant improvement in the biocompatibility and cytocompatibility of the materials used, and the implementation of products with significant micro-roughness that improve osseointegration are the well-known and commonly used effects of this cooperation today .

Materials science related to orthopedics is an extremely complex and multi-threaded field. Its continuous development requires a periodic summary of the results and development directions provided, which allows faster evaluation and interpretation by researchers. The purpose of the following work is to summarize the latest research on materials and methods used in osteosynthesis in a legible way for potential recipients of this information from various fields.
professional Nooks Reviews
Authors: Marycz Adam , Celinska Angelica
Published: July 2022

From social impact to a play-based curriculum in Key Stage 1, the professional books should spark both reflection and action. The picture books are also thought-provoking, from diversity to evolution.
Should videolaryngoscopy be used first line for all intubations in the post-COVID-19 era?
Authors: Kumaran Geevithan , Gorur Paavan
Published: July 2022

While previously reserved for use in patients with difficult airways or for trainee education, videolaryngoscopy has come to the forefront of anaesthesia after its use as first line in the intubation of all patients with suspected or confirmed COVID-19. This article examines its suitability for routine first line use in all intubations.
Testing the Accuracy of an Age Estimation Method Using Radiographs of Permanent Mandibular Third Molar Teeth in a Thai Population
Authors:   Department of Orthodontics, School of Dentistry, University of Phayao, Phayao 56000, Thailand, Theerasopon Pornpat , Tiansuwan Kanyathorn ,   School of Dentistry, University of Phayao, Phayao 56000, Thailand, Srichaitan Natthanan ,   School of Dentistry, University of Phayao, Phayao 56000, Thailand, Norkaew Sichanad ,   School of Dentistry, University of Phayao, Phayao 56000, Thailand, Charoemratrote Chairat ,   Department of Preventive Dentistry, Faculty of Dentistry, Prince of Songkla University, Songkhla 90112, Thailand, Srimaneekarn Natchalee ,   Department of Anatomy, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand, Duangto Phuwadon ,   Department of Anatomy, School of Medical Sciences, University of Phayao, Phayao 56000, Thailand
Published: July 2022

Abstract The aim of this study was to test the accuracy of an age estimation method using the radiographs of permanent mandibular third molar teeth in a Southern Thai population. Digital panoramic radiographs of 480 Thai samples (240 males and 240 females) aged from 8 to 23 years were selected and divided into 16 age groups. The permanent mandibular third molar teeth were separated into nine developmental stages according to the Demirjian et al. classification. The developmental stage was evaluated and then converted into a developmental score. Accuracy of the dental age estimation was tested using regression equations according to the Duangto et al. study. Our results showed that dental age was close to the chronological age within one year for both sexes. In conclusion, the age estimation equations according to the Duangto et al. study provide an accurate age estimation in a Southern Thai population. Keywords: Dental age estimation, Demirjian et al. classification, Mandibular third molar teeth, Thai population
Generalized Finite Difference Method for Solving Waveguide Eigenvalue Problems
Authors: Xu Hui , Bao Yang
Published: July 2022

The generalized finite difference method (GFDM) is a meshless method that has become popular in recent years. The basic theory underlying GFDM is to expand the point cluster function value at the center node by Taylor’s formula and then obtain the best linear combinations of these function values to represent the derivative at the central node by the least square fitting technique. Subsequently, the minimized weighted error between the approximated value and the accurate value is obtained. This paper establishes the general steps for solving waveguide eigenvalue problems with GFDM. Excellent performance is shown by comparing the proposed method and other common solutions. The robustness of the proposed method is verified by calculating the cutoff wavenumbers of typical waveguides and the eccentric circular waveguide in different modes.
Design and Development of Substrate Integrated Waveguide Based Filtenna for X Band Application
Authors: Vimala G. S. Annie Grace , Prakash V. R. , Akilandeswari A. , Sungeetha D. , Saravanan M.
Published: July 2022

In this paper, substrate integrated waveguide based filtenna operating at X band is proposed. The model is designed on a low-loss dielectric substrate having a thickness of 1.6 mm and comprises shorting vias along two edges of the substrate walls. To realize a bandpass filter, secondary shorting vias are placed close to primary shorting vias. The dimension and position of the vias are carefully analyzed for X band frequencies. The model is fabricated on Roger RT/duroid 5880 and the performance characteristics are measured. The proposed model achieves significant impedance characteristics with wider bandwidth in the X band. The model also achieves a maximum gain of 7.46 dBi in the operating band, thus making it suitable for X band applications.
Determination of Geographical Origin and Tree Species Using Vis-NIR and Chemometric Methods
Authors: Li Ying , Via Brian K. , Li Yaoxiang , Wang Guozhong
Published: July 2022

The variation of wood properties between different geographical origin and tree species has an important influence on end use applications. This study aimed to investigate the feasibility of wood origin and species classification based on visible and near infrared spectroscopy and chemometric methods. The influence of geographical origin on tree species identification also was analyzed. A total of 530 samples with 2 origins and 5 tree species were collected for analysis. The raw reflectance spectra were preprocessed by spectral transformation technique, and nonlinear discrimination models were built by support vector machine (SVM) using various spectral forms. Three algorithms—grid search (GS), genetic algorithm (GA), and particle swarm optimization (PSO)—were applied to optimize the parameters of SVM models, respectively. Regardless of spectral forms and optimization techniques, the prediction accuracy was lower than that of the calibration set for wood origin and tree species identification. Except for reflectance spectra, prediction accuracy of 100 percent was obtained based on SVM in combination with three algorithms for origin discrimination. However, SVM in combination with reflectance spectra and GS technique achieved the best prediction accuracy (93.18%) for tree species identification. These results demonstrated that visible and near infrared spectroscopy combined with chemometric techniques can be used for geographical origin and tree species determination.
Monte Carlo–transformed field expansion method for simulating electromagnetic wave scattering by multilayered random media
Authors: Ulmer Kelsey , Lin Junshan , Nicholls David P.
Published: July 2022

We present an efficient numerical method for simulating the scattering
of electromagnetic fields by a multilayered medium with random
interfaces. The elements of this algorithm, the Monte
Carlo–transformed field expansion method, are (i) an interfacial
problem formulation in terms of impedance-impedance operators, (ii)
simulation by a high-order perturbation of surfaces approach (the
transformed field expansions method), and (iii) efficient computation
of the wave field for each random sample by forward and backward
substitutions. Our perturbative formulation permits us to solve a
sequence of linear problems featuring an operator that is deterministic, and its LU decomposition matrices
can be reused, leading to significant savings in computational effort.
With an extensive set of numerical examples, we demonstrate not only
the robust and high-order accuracy of our scheme for small to moderate
interface deformations, but also how Padé summation can be used to
address large deviations.
Optical spatial filtering with plasmonic directional image sensors
Authors: Liu Jianing , Wang Hao , Kogos Leonard C. , Li Yuyu , Li Yunzhe , Tian Lei , Paiella Roberto
Published: July 2022

Photonics provides a promising approach for image processing by spatial filtering, with the advantage of faster speeds and lower power consumption compared to electronic digital solutions. However, traditional optical spatial filters suffer from bulky form factors that limit their portability. Here we present a new approach based on pixel arrays of plasmonic directional image sensors, designed to selectively detect light incident along a small, geometrically tunable set of directions. The resulting imaging systems can function as optical spatial filters without any external filtering elements, leading to extreme size miniaturization. Furthermore, they offer the distinct capability to perform multiple filtering operations at the same time, through the use of sensor arrays partitioned into blocks of adjacent pixels with different angular responses. To establish the image processing capabilities of these devices, we present a rigorous theoretical model of their filter transfer function under both coherent and incoherent illumination. Next, we use the measured angle-resolved responsivity of prototype devices to demonstrate two examples of relevant functionalities: (1) the visualization of otherwise invisible phase objects and (2) spatial differentiation with incoherent light. These results are significant for a multitude of imaging applications ranging from microscopy in biomedicine to object recognition for computer vision.
TEM-wave propagation in a coaxial waveguide with impedance-matched RHM to LHM transition
Authors: Rana Balwan , Svendsen Brage B. , Dalarsson Mariana
Published: July 2022

In this paper, we study TEM-wave propagation inside a hollow coaxial waveguide filled with an inhomogeneous metamaterial composite, with a graded transition between a right-handed material (RHM) and an impedance-matched left-handed material (LHM). The graded transition and the TEM-wave propagation occur in the direction perpendicular to the boundary between the two media, which has been chosen to be the z-direction. The relative permittivity ɛ(ω, z) and permeability µ(ω, z) of the RHM-LHM composite vary according to hyperbolic tangent functions along the z-direction. The exact analytical solutions to Maxwell’s equations are derived, and the solutions for the field components and wave behavior confirm the expected properties of impedance-matched RHM-LHM structures. Furthermore, a numerical study of the wave propagation over an impedance-matched graded RHM-LHM interface, using the COMSOL Multiphysics software, is performed. An excellent agreement between the analytical results and numerical simulations is obtained, with a relative error of less than 0.1%. The present method has the ability to model smooth realistic material transitions, and includes the abrupt transition as a limiting case. Finally, the RHM-LHM interface width is included as a parameter in the analytical and numerical solutions, allowing for an additional degree of freedom in the design of practical devices using RHM-LHM composites.
Atmospheric air plasma sustainment by semiconductor microwave for hydroxyl radical production and powder metal element analysis
Authors: Ikeda Yuji
Published: July 2022

A semiconductor microwave device that generates a series of burst microwaves at a sub-microsecond duration has been successfully used in a breakdown plasma spectrometer in atmospheric conditions. Microwave delivery has been changed to couple the microwave with laser sparks and electric sparks which are typical plasma ignition sources in laser-induced breakdown spectroscopy (LIBS) and spark-induced breakdown spectroscopy (SIBS). A helical antenna was used for the laser spark, while a coaxial antenna was considered more appropriate for the electric spark. The weak and transient sparks in LIBS and SIBS are enlarged by the microwaves which are stably sustained in the air. The microwave's output power and pulse duration are easily controllable, resulting in tunable plasma intensity and sustained production of hydroxyl radicals (OH radicals). Even in continuous-wave operation by microwave, the low-energy system prevented the formation of high-temperature thermal plasma (>10,000 K) without any mechanical cooling system. The microwave-enhanced LIBS (MW-LIBS) and microwave-enhanced SIBS (MW-SIBS) could be applied to optical emission spectroscopy analyses. In analytical applications, MW-SIBS produces no shockwave in contrast with MW-LIBS which is a great advantage in powdered samples. The MW-SIBS successfully analyzed the direct introduction of copper metal powders.
Optical time domain backscattering of antiresonant hollow core fibers
Authors: Slavík Radan , Numkam Fokoua Eric R. , Bradley Thomas D. , Taranta Austin A. , Komanec Matěj , Zvánovec Stanislav , Michaud-Belleau Vincent , Poletti Francesco , Richardson David J.
Published: July 2022

Today’s lowest-loss hollow core fibers are based on antiresonance guidance. They have been shown both theoretically and experimentally to have very low levels of backscattering arising from the fiber structure – 45 dB below that of traditional optical fibers with a solid silica glass core. This makes their longitudinal characterization using conventional reflectometric techniques very challenging. However, it was recently estimated that when filled with air, their backscattering coefficient increases to about 30 dB below that of standard solid core fibers. This level should be measurable with commercially available high performance optical time domain reflectometers (OTDR). Here we demonstrate – for the first time to the best of our knowledge – the measurement of backscattering from the air inside a hollow core fiber. We show that the characterization of multi-km long hollow core fibers with 15 m spatial resolution is possible using a commercial OTDR instrument. To benefit from its full dynamic range, we strongly suppress the 4% back-reflections that ordinarily occur at the OTDR’s standard fiber output when directly-connected to a hollow core fiber. Furthermore, low coupling loss into the hollow core fiber (0.3 dB in our experiment) also helps to maximize the achievable OTDR signal-to-noise ratio. This approach enables distributed characterization and fault-finding in low-loss hollow core fibers, a topic of increasing importance as these fibers are now starting to be installed in commercial optical communication networks.
Circular dichroism in magneto-optical forces
Authors: Edelstein Shulamit , Garcia-Martin Antonio , Serena Pedro A. , Marqués Manuel I.
Published: July 2022

In this article we use an exact method to resolve the fields scattered by a spherical magneto-optical particle and calculate the optical forces exerted on it. The resulting force and the contributing components, i.e. magneto-optical gradient force and magneto-optical extinction force, are presented in an analytical form. We also derive analytical expressions for the scattering and extinction cross sections of a magneto-optical particle, expressions which intuitively demonstrate the effect of circular dichroism in magneto-optical scattering and forces. Finally, we demonstrate that the magneto-optical extinction force is the result of circular dichroism in magneto-optical scattering. We show that it is possible to completely cancel the scattering in the forward or in the backward direction, when the incident field is composed of a circularly-polarized reflected beam. Moreover, the directional scattering is interrelated to the direction of the force exerted on the particle.
Characterization of encapsulated graphene layers using extreme ultraviolet coherence tomography
Authors: Wiesner Felix , Skruszewicz Slawomir , Rödel Christian , Abel Johann Jakob , Reinhard Julius , Wünsche Martin , Nathanael Jan , Grünewald Marco , Hübner Uwe , Paulus Gerhard G. , Fuchs Silvio
Published: July 2022

Many applications of two-dimensional materials such as graphene require the encapsulation in bulk material. While a variety of methods exist for the structural and functional characterization of uncovered 2D materials, there is a need for methods that image encapsulated 2D materials as well as the surrounding matter. In this work, we use extreme ultraviolet coherence tomography to image graphene flakes buried beneath 200 nm of silicon. We show that we can identify mono-, bi-, and trilayers of graphene and quantify the thickness of the silicon bulk on top by measuring the depth-resolved reflectivity. Furthermore, we estimate the quality of the graphene interface by incorporating a model that includes the interface roughness. These results are verified by atomic force microscopy and prove that extreme ultraviolet coherence tomography is a suitable tool for imaging 2D materials embedded in bulk materials.
Single-step etched two-dimensional polarization splitting dual-band grating coupler for wavelength (de)multiplexing
Authors: Cheng Guanglian , Yi Qiyuan , Li Qiyuan , Yan Zhiwei , Xu Fanglu , Zou Yongchao , Li Ting , Zou Yi , Yu Yu , Shen Li
Published: July 2022

Diffractive periodic-structure-based grating couplers (GCs) are the most widely used devices for light coupling between optical fibers and integrated photonic devices. However, conventional GCs have limited wavelength operation and are polarization specific, which is due to the intrinsic radiation angle dependency on both wavelength and polarization. Here we propose and experimentally demonstrate a polarization-splitting dual-band grating coupler (PS-DBGC) for polarization diversity and wavelength division (de)multiplexing (WDM) operation. The four-port two-dimensional PS-DBGC is based on a periodically arranged structure with square holes, and requires only a single etch step in a 340-nm silicon-on-insulator platform. The simulation predicts that the maximum coupling efficiency (CE) of the proposed PS-DBGC is −2.8 dB and −4.6 dB for the O- and C-band, respectively. The measured peak CEs of the fabricated device are −4.7 dB at 1280 nm and −8.4 dB at 1522 nm. We anticipate that this PS-DBGC could potentially improve the performance of any future integrated WDM passive optical network.
Interferometric cavity ringdown technique for ultrahigh Q-factor microresonators
Authors: Biasi Stefano , Franchi Riccardo , Pavesi Lorenzo
Published: July 2022

Microresonators (MRs) are key components in integrated optics. As a result, the estimation of their energy storage capacity as measured by the quality factor (Q) is crucial. However, in MRs with high/ultrahigh Q, the wall-surface roughness dominates the intrinsic Q and generates a coupling between counter-propagating modes. This splits the usual sharp single resonance and makes the use of classical methods to assess Q difficult. Here, we theoretically show that an interferometric excitation can be exploited in a cavity ringdown (CRD) method to measure the ultimate Q of a MR. In fact, under suitable conditions, the resonant doublet merges into a single Lorentzian, and the time dynamics of the MR assumes the usual behavior of a single-mode resonator unaffected by backscattering. This allows us to obtain a typical exponential decay in the charging and discharging time of the MR, and thus, to estimate its ultimate Q by measuring the photon lifetime.
A bifocal compound liquid lens with continuous zoom based on selective wettability
Authors: Huang Yayan , Zhao Rui , Miao Wenhao , Liang Dan , Liu Zhiqiang , Wei Xian , Liang Zhongcheng
Published: July 2022

In this paper, a tunable zoom bifocal liquid lens based on selective wettability is proposed. This lens consists of internal and external immiscible coaxial droplets surrounded by immiscible ambient liquid. Since curvatures and refractive indexes of the internal and external droplets are different, the system forms a long focus and a short focus, respectively. By applying different voltages, the curvatures of the internal and external droplets change exerting continuous movement of a long/short focal point in a certain range. To verify the feasibility and practicability of this concept, a prototype of the bifocal compound lens is fabricated in experiment, and the modulation ability of its long/short focal length is detected. The short focal length of our proposed lens varies from 15.46 mm to 17.47 mm, while the relative long focal length ranges from 96.25 mm to 70.31 mm driven by 200 V.
Vector space-time wave packets
Authors: Yessenov Murat , Chen Zhaozhong , Lavery Martin P. J. , Abouraddy Ayman F.
Published: July 2022

Space-time wave packets (STWPs) are propagation-invariant pulsed beams whose characteristics stem from the tight association between their spatial and temporal degrees of freedom. Until recently, only scalar STWPs have been synthesized in the form of light sheets. Here we synthesize vector STWPs that are localized in all dimensions by preparing polarization-structured spatiotemporal spectra and unveil the polarization distribution over the STWP volume via time-resolved complex field measurements. Such vector STWPs are endowed with cylindrically symmetric polarization vector structures, which require joint manipulation of the spatial, temporal, and polarization degrees of freedom of the optical field. These results may be useful in particle manipulation, and in nonlinear and quantum optics.
Nodeless antiresonant hollow core fiber for low loss flatband THz guidance
Authors: Sultana Azra Sadia , Khaleque Abdul , Shaha Kumary Sumi Rani , Rahman Mafin Muntasir , Hosen Md. Sarwar
Published: July 2022

This paper reveals a THz leading nodeless antiresonant slotted hollow core fiber (NARS-HCF) with low transmission loss and broad band flat near zero dispersion. We have achieved better results in a simpler structure as far as we know: a minimal confinement loss in the order of around 10−4 dBm-1 and a very low effective material loss of 0.0248 dBm-1, resulting in a lowest total transmission loss of 0.0254 dBm-1 at 1.27 THz and offering a 0.88 THz (0.8 THz – 1.68 THz) low loss transmission bandwidth with the loss of less than 0.0811 dBm-1. Additionally, we achieved a 0.0614 ± 0.0468 ps/THz/cm near zero flat dispersion over the widest bandwidth of 1.02 THz (0.80 THz to 1.82 THz). Moreover, our proposed structure can also effectively perform as single mode fiber with excellent bending loss performance, hence, can be useful for efficient THz transmission systems.
Local and collective transitions in sparsely-interacting ecological communities
Authors: Marcus Stav , Turner Ari M. , Bunin Guy
Published: July 2022

Interactions in natural communities can be highly heterogeneous, with any given species interacting appreciably with only some of the others, a situation commonly represented by sparse interaction networks. We study the consequences of sparse competitive interactions, in a theoretical model of a community assembled from a species pool. We find that communities can be in a number of different regimes, depending on the interaction strength. When interactions are strong, the network of coexisting species breaks up into small subgraphs, while for weaker interactions these graphs are larger and more complex, eventually encompassing all species. This process is driven by the emergence of new allowed subgraphs as interaction strength decreases, leading to sharp changes in diversity and other community properties, and at weaker interactions to two distinct collective transitions: a percolation transition, and a transition between having a unique equilibrium and having multiple alternative equilibria. Understanding community structure is thus made up of two parts: first, finding which subgraphs are allowed at a given interaction strength, and secondly, a discrete problem of matching these structures over the entire community. In a shift from the focus of many previous theories, these different regimes can be traversed by modifying the interaction strength alone, without need for heterogeneity in either interaction strengths or the number of competitors per species.
The accuracy of absolute differential abundance analysis from relative count data
Authors: Roche Kimberly E. , Mukherjee Sayan
Published: July 2022

Concerns have been raised about the use of relative abundance data derived from next generation sequencing as a proxy for absolute abundances. For example, in the differential abundance setting, compositional effects in relative abundance data may give rise to spurious differences (false positives) when considered from the absolute perspective. In practice however, relative abundances are often transformed by renormalization strategies intended to compensate for these effects and the scope of the practical problem remains unclear. We used simulated data to explore the consistency of differential abundance calling on renormalized relative abundances versus absolute abundances and find that, while overall consistency is high, with a median sensitivity (true positive rates) of 0.91 and specificity (1—false positive rates) of 0.89, consistency can be much lower where there is widespread change in the abundance of features across conditions. We confirm these findings on a large number of real data sets drawn from 16S metabarcoding, expression array, bulk RNA-seq, and single-cell RNA-seq experiments, where data sets with the greatest change between experimental conditions are also those with the highest false positive rates. Finally, we evaluate the predictive utility of summary features of relative abundance data themselves. Estimates of sparsity and the prevalence of feature-level change in relative abundance data give reasonable predictions of discrepancy in differential abundance calling in simulated data and can provide useful bounds for worst-case outcomes in real data.
Thalamic deep brain stimulation paradigm to reduce consciousness: Cortico-striatal dynamics implicated in mechanisms of consciousness
Authors: Redinbaugh Michelle J. , Afrasiabi Mohsen , Phillips Jessica M. , Kambi Niranjan A. , Mohanta Sounak , Raz Aeyal , Saalmann Yuri B.
Published: July 2022

Anesthetic manipulations provide much-needed causal evidence for neural correlates of consciousness, but non-specific drug effects complicate their interpretation. Evidence suggests that thalamic deep brain stimulation (DBS) can either increase or decrease consciousness, depending on the stimulation target and parameters. The putative role of the central lateral thalamus (CL) in consciousness makes it an ideal DBS target to manipulate circuit-level mechanisms in cortico-striato-thalamic (CST) systems, thereby influencing consciousness and related processes. We used multi-microelectrode DBS targeted to CL in macaques while recording from frontal, parietal, and striatal regions. DBS induced episodes of abnormally long, vacant staring with low-frequency oscillations here termed vacant, perturbed consciousness (VPC). DBS modulated VPC likelihood in a frequency-specific manner. VPC events corresponded to decreases in measures of neural complexity (entropy) and integration (Φ*), proposed indices of consciousness, and substantial changes to communication in CST circuits. During VPC, power spectral density and coherence at low frequencies increased across CST circuits, especially in thalamo-parietal and cortico-striatal pathways. Decreased consciousness and neural integration corresponded to shifts in cortico-striatal network configurations that dissociated parietal and subcortical structures. Overall, the features of VPC and implicated networks were similar to those of absence epilepsy. As this same multi-microelectrode DBS method–but at different stimulation frequencies–can also increase consciousness in anesthetized macaques, it can be used to flexibly address questions of consciousness with limited confounds, as well as inform clinical investigations of other consciousness disorders.
Identification of a linear B-cell epitope on the Schistosoma japonicum saposin protein, SjSAP4: Potential as a component of a multi-epitope diagnostic assay
Authors: Mu Yi , Gordon Catherine A. , Olveda Remigio M. , Ross Allen G. , Olveda David U. , Marsh Jessica M. , McManus Donald P. , Cai Pengfei
Published: July 2022

Background

Schistosoma japonicumis one of three major species of blood flukes causing schistosomiasis, a disease, which continues to be a major public health issue in the Philippines. SjSAP4, a member of a multigene family of saposin-like proteins, is a recognized immunodiagnostic biomarker for schistosomiasis japonica. This study aimed to identify linear B-cell epitopes on SjSAP4 and to validate their potential as components of a multi-epitope assay for the serological diagnosis of schistosomiasis japonica.

Methodology

SjSAP4-derived peptides were expressed as GST-peptide-fused proteins and these were Western blot probed with human serum samples fromS.japonicumKato-Katz (KK)-positive individuals and uninfected controls. A core epitope was further identified by Western blotting through probing a series of truncated peptides with the schistosomiasis patient sera. The diagnostic performance of the core epitope-containing peptides and the full-length SjSAP4 was evaluated by enzyme-linked immunosorbent assay (ELISA) using a panel of sera collected from subjects resident in a schistosomiasis-endemic area of the Philippines.

Main findings

As a result of the peptide mapping, one peptide (P15) was found to be highly immunogenic in the KK-positive individuals. We subsequently showed that -S163QCSLVGDIFVDKYLD178- is a core B-cell epitope of P15. Subsequent ELISAs incorporating SjSAP4, SjSAP4-Peptide and SjSP-13V2-Peptide showed a sensitivity of 94.0%, 46.0% and 74.0%, respectively, and a specificity of 97.1%, 100% and 100%, respectively. Notably, complementary recognition of the B-cell epitopes (SjSAP4-Peptide and SjSP-13V2-Peptide) was observed in a subset of the KK-positive individuals. A dual epitope-ELISA (SjSAP4-Peptide + SjSP-13V2-Peptide-ELISA) showed a diagnostic sensitivity of 84.0% and a specificity of 100%.

Conclusions/Significance

In this study, -S163QCSLVGDIFVDKYLD178- was identified as a dominant linear B-cell epitope on SjSAP4. This peptide and the complementary recognition of other B-cell epitopes using sera from different KK-positive individuals can provide the basis of developing a multi-epitope assay for the serological diagnosis of schistosomiasis.
VCSEL pair used as optical pointers in a contact lens for gaze tracking and visual target designation
Authors: Robert François-Maël , Nourrit Vincent , Adam Laure , de Bougrenet de la Tocnaye Jean-Louis
Published: July 2022

We present a new eye-tracking and target designation device based on a contact lens incorporating a pair of vertical-cavity surface-emitting lasers (VCSELs). We describe the operating principle, the manufacturing process and characterize the impact of the VCSELs encapsulation on their optical properties. We then describe how such device can be incorporated into an eye-wear or a visual augmented system. We compare two different detection set-ups, the first using a camera and the second a position sensitive device, both illustrating different laser beam detection modes. We analyze their performances in terms of angular accuracy, speed, compactness, manufacturability, compared to current conventional eye-tracking systems. We emphasize how the use of two VCSELs and the control of their orientation during the encapsulation can simplify their integration in host systems and improve the gaze detection performance. Finally, we describe various embodiments and discuss potential improvements that can be expected in future systems.
Six weeks of whole-body vibration improves fine motor accuracy, functional mobility and quality of life in people with multiple sclerosis
Authors: Krause Anne , Lee Kyungsoo , König Daniel , Faist Michael , Freyler Kathrin , Gollhofer Albert , Ritzmann Ramona
Published: July 2022

People with multiple sclerosis (MS) suffer from sensorimotor deficits with the distal extremities being more severely affected than proximal ones. Whole-body vibration (WBV) training is known to enhance voluntary activation and coordination in healthy people. However, evidence about beneficial effects of WBV in MS patients is scarce. The current study aimed to investigate if six weeks of WBV enhances motor function in the ankle joint, coordination and quality of life in patients suffering from severe MS. In a longitudinal design, changes in motor function and quality of life were assessed before and after a 6-week control period without a training (CON) and a 6-week WBV training (2-3x/week) in 15 patients (53 ±10 years) with advanced MS (EDSS 3–6.5). Before CON (t0), after CON (t1) and after WBV(t2), outcome measures included (1) active range of motion (aROM) and (2) motor accuracy at the ankle joint, (3) functional mobility (Timed “Up & Go” test with preferred and non-preferred turns) and (4) physical and psychological impact of MS (MSIS-29 questionnaire). For (1) and (2), the stronger (SL) and the weaker leg (WL) were compared. After WBV, aROM (1) did not change (SL p = 0.26, WL p = 0.10), but was diminished after CON (SL -10% p = 0.06, WL -14% p = 0.03) with significant group differences (Δgroup WL p = 0.02). Motor accuracy in SL (2) was improved during dorsal flexion after WBV (p = 0.01, Δgroup p = 0.04) and deteriorated during plantar flexion after CON (p = 0.01, Δgroup p = 0.04). Additionally, participants (3) improved their functional mobility at the preferred turn (p = 0.04) and (4) ranked their quality of life higher solely after WBV (p = 0.05), without any differences between groups. However, values correlated significantly between angular precision and aROM as well as functional mobility. No further changes occurred. The results point towards an interception of degenerating mono-articular mobility and improvement of accuracy in the ankle joint. The motor effects after WBV are in line with enhanced perception of quality of life after six weeks which is why WBV could be a stimulus to enable greater overall autonomy in MS patients.