bluuebunny/crossref_metadata_2025 huggingface dataset:
A MORPHOLOGICAL REVIEW OF MEDIAL MALLEOLAR FRACTURES: ARE THERE ANY FACTORS WHICH MAY PREDISPOSE TO NONUNION AND MALUNION?
Authors: Aamir J. , Caldwell R. , Long S. , Sreenivasan S. , Mayrotas J. , Panera A. , Jeevaresan S. , Mason L.
Published: June 2024

Background

Many approaches to management of medial malleolar fractures are described in the literature however, their morphology is under investigated. The aim of this study was to analyse the morphology of medial malleolar fractures to identify any association with medial malleolar fracture non-union or malunion.

Methods

Patients who had undergone surgical fixation of their MMF were identified from 2012 to 2022, using electronic patient records in a single centre. Analysis of their preoperative, intraoperative, and postoperative radiographs was performed to determine their morphology and prevalence of non-union and malunion. Lauge-Hansen classification was used to characterise ankle fracture morphology and Herscovici classification to characterise MMF morphology.

Results

A total of 650 patients were identified across a 10-year period which could be included in the study. The overall non-union rate for our cohort was 18.77% (122/650). The overall malunion rate was 6.92% (45/650). There was no significant difference in union rates across the Herscovici classification groups. Herscovici type A fractures were significantly more frequently malreduced at time of surgery as compared to other fracture types (p=.003). Medial wall blowout combined with Hercovici type B fractures showed a significant increase in malunion rate. There is a higher rate of bone union in patients who have been anatomically reduced.

Conclusion

The morphology of medial malleolar fractures does have an impact of the radiological outcome following surgical management. Medial wall blowout fractures were most prevalent in adduction-type injuries; however, it should not be ruled out in rotational injuries with medial wall blowouts combined with and Herscovici type B fractures showing a significant increase in malunions. Herscovici type A fractures had significantly higher malreductions however the clinical implications of mal reducing small avulsions is unknown.
UNVEILING TRUTH
Authors: Moutinho Barroso Paulo Alexandre
Published: June 2024

Flusser’s thoughts on truth and objectivity in technical images are complex and increasingly pertinent in current visual cultures. His perspective is rooted in his philosophical examination of the role of photography and other technical images in modern society, regarding the new forms of information, standardized and reproduced meaning processes, interpretation and objectivity of the image-making and image-decoding processes. According to Flusser, while technical images have objective surfaces and are created through standardized processes, their ultimate meaning and truth are subject to interpretation and influenced by human decisions and cultural contexts. This article follows a theoretical and conceptual approach in the framework of Flusser’s philosophy of photography and its purposes are: a) to understand contemporary media and visual culture in shaping our conception of the world; b) to argue the ethical implications of technical images; and c) to demonstrate that Flusser’s work on the truth and objectivity of technical images serves various purposes and fields, and provides a framework for exploring the profound impact of technology on our perception of reality and the representation of truth.
FILOSOFIA NOS MOLDES DA POESIA
Authors: BATLIČKOVÁ EVA
Published: June 2024

RESUMO: O presente artigo procura contextualizar a crítica de Flusser ao discurso acadêmico na filosofia e a busca das alternativas que recorrem a elementos literários. Fontes de inspiração de Flusser podem ser encontradas na filosofia alemã das décadas de 1930 e 1940, mas também no próprio ambiente cultural e intelectual de Praga. Embora Flusser tenha se tornado conhecido pela forma ensaística de seus textos, focamos aos seus primeiros passos no campo da escrita que se deram no campo literário no sentido estrito do termo. Levantamos uma série de aspectos na sua peça poética de teatro Saul (1936) com intuito de apontar às raízes do seu trabalho com texto e do modo de abordar tanto os problemas urgentes da sua época como os temas essencialmente filosóficos.
PALAVRAS-CHAVE: Filosofia alemã, Poesia, Drama, Antissemitismo, Segunda Guerra Mundial.
 
ABSTRACT: This article seeks to contextualize Flusser's criticism of academic discourse in philosophy and the search for alternatives that use literary elements. Sources of Flusser's inspiration can be found in German philosophy of the 1930s and 1940s, but also in Prague's own cultural and intellectual environment. Although Flusser became known for the essayistic form of his texts, we focus on his first steps in the field of writing, which took place in the literary field in the strict sense of the term. We raised a series of aspects in his poetic play Saul (1936) with the aim of pointing out the roots of his work with text and the way he approached both the urgent problems of his time and essentially philosophical themes.
KEYWORDS: German philosophy, Poetry, Drama, Anti-Semitism, World War II.
The Cosmopolitan Symbolism of Launcelot Cranmer-Byng
Authors: Murray Alex
Published: June 2024

Abstract: This article offers the first comprehensive overview of the cosmopolitan Symbolist poet Launcelot Cranmer-Byng (1872–1945), who was active from the 1890s through to the late 1930s. Tracking his creative and translational practice from the French, Portuguese, and Chinese, I argue that his work offers us a much more expansive and transnational mode of Symbolism than those that dominate the scholarship to date. Writing under pseudonyms, ranging from drama to poetic ‘renderings’ and the creative essay, Cranmer-Byng developed an idiosyncratic oeuvre that saw Symbolism as a universal means of expressing vitalism and hope in an increasingly bleak world.
Liberal Funerals, Political Resistance and Sites of Martyrdom in the Late Russian Empire
Authors: Gilbert George
Published: June 2024

Abstract: This article explores a series of political funerals held for major liberal figures during the early years of the twentieth century within the Russian Empire. Using three major figures — the philosopher and university rector Sergei Trubetskoi, lawyer Lev Kupernik and politician Sergei Muromtsev — as its primary examples, it considers the importance of both space and place, focusing on demonstrations held in support of these individuals in Moscow and Kyiv. Drawing on a range of sources including the periodical press and hitherto untapped police records, it explores the circumstances behind the appearance of liberal political funerals, and the novelty of such events in relation to well-established traditions surrounding the political funeral in the late Russian Empire. It looks at who attended, the size and intensity of the disturbances that followed, and how onlookers and supporters interacted with these events. Conceptually, it assesses whether the causes that the subjects of these political funerals stood for, such as selfhood, subjectivity and citizenship, spoke to a particularly liberal tradition of protest which intersected with the wider currents of dissent by then endemic in different parts of the empire. Finally, it considers whether there was a liberal tradition in terms of political martyrdom in the late Russian Empire and to what extent this was used to advance the political causes espoused by supporters of these liberal figureheads.
Precision manipulation by an optically induced dielectrophoresis system based on an improved A-star algorithm
Authors: Du Mingao , Liu Fei , Li Gongxin
Published: June 2024

Cell manipulation using optically induced dielectrophoresis (ODEP) in a microfluidic
system has drawn much attention due to its simplicity and being
damage-free at the cellular level. Additionally, to improve its
manipulation efficiency and accuracy, automatic manipulation methods
have been applied in the ODEP system. However, the current automatic
manipulation methods of ODEP rarely consider the impact of
non-manipulated targets on cell manipulation, thereby reducing the
operating efficiency and accuracy. Here, we propose a new, to our
knowledge, automatic manipulation method of ODEP based on a path
planning algorithm of the improved A-star. First, the maximum
influence range of ODEP force generated by the virtual electrode was
investigated by a numerical simulation, and it was also taken as the
limit to expand the scope of the infeasible region in path planning to
avoid the impact of the non-operational target on manipulation
accuracy. Then, an improved A-star algorithm with target range
constraints was proposed to optimize the manipulation path and improve
the operation efficiency. Finally, experiments on cell separation were
also carried out to validate the feasibility of the proposed automatic
manipulation method. This work provides an automated method to improve
the accuracy of ODEP manipulation, which is of great significance to
further promote the application of ODEP in cell manipulation.
Deep jointly optical spectral band selection and classification learning
Authors: Fonseca Karen , Bacca Jorge , Garcia Hans , Arguello Henry
Published: June 2024

Spectral data provide material-specific information across a broad electromagnetic wavelength range by acquiring numerous spectral bands. However, acquiring such a significant volume of data introduces challenges such as data redundancy, long acquisition times, and substantial storage capacity. To address these challenges, band selection is introduced as a strategy that focuses on only using the most significant bands to preserve spectral information for a specific task. State-of-the-art methods focus on searching for the most significant bands from previously acquired data, regardless of the optical system and the classification model. Nevertheless, some deep-learning methods, such as end-to-end frameworks, allow the design of optical systems and the learning of the classification network parameters. In this paper, we model the optical band selection as a trainable layer that is coupled with a classification network, where the parameters are learned in an end-to-end framework. To guarantee a physically implementable system, we proposed two regularization terms in the training step to promote binarization and also the number of the selected bands, as we need to provide the conditions to design the physical element where the light passes through. The proposed method provides better performance than state-of-the-art band selection methods for three different spectral datasets under the same conditions.
Hartmann test using a screen with arbitrarily positioned holes
Authors: Araiza-Durán José A. , Herrera Joel , Luna Esteban , Sohn Erika , Brucalassi Anna , Salas Luis
Published: June 2024

We present a novel, to the best of our knowledge, approach for reconstructing wavefronts from hartmanngrams, eliminating the need for precise hole position information. This technique utilizes both intra- and extrafocal hartmanngrams to assign a set of direction cosines to each ray. By employing these direction cosines and a ray tracing optimization process, the wavefront can be effectively recovered. The methodology will be outlined, the Hartmann test using two kinds of screens will be simulated, and the results obtained will be discussed.
Cultural relics fragment assembly based on fracture surface contour features
Authors: Wang Xiaohui , Fu Siyong
Published: June 2024

Addressing the issue of registration deviations caused by local fragment loss and shape diversity during the process of cultural relics fragment assembly, this paper proposes a method for assembling cultural relics fragments based on the contour features of fracture surfaces. Initially, the curvature of discrete point clouds is calculated using the quartic surface method and the Weingarten matrix, and curvature discontinuity points are identified using a proportional method as a candidate feature point set. Subsequently, the angle difference between a point and its neighboring points’ directed segments is defined as a neighborhood feature parameter, which further optimizes the feature point set and selects the optimal matching set. Then the 4-points congruent sets (4PCS) algorithm is utilized for the initial registration of the fragments, and the unit quaternion method is employed to calculate the rigid body transformation matrix during the iteration process. Finally, corresponding point pairs are determined by the intersection of a point’s normal with a set of points, improving the iterative closest point (ICP) algorithm to achieve precise assembly of the fragments. The experimental results show that, compared to other assembly algorithms, the proposed method is more accurate in feature point extraction, robust, and effectively enhances the accuracy and efficiency of fragment assembly.
Analysis of the zoom system of a microscope condenser and its modification using variable focus lenses
Authors: Mikš Antonín , Novák Jiří
Published: June 2024

A detailed theoretical analysis and optimization of the classical three-element zoom (pancratic) microscope condenser according to a patent from the 1930s [Reichspatentamt Nr. 713188 (29 10 1936)] is performed and formulas are derived for calculating basic parameters and the displacement of lenses during zooming. Furthermore, the modification of the classical zoom microscope condenser is investigated using a simpler optical system of two lenses with variable focal lengths and fixed positions. The relations for the calculation of the focal lengths of both variable focus lenses and the basic parameters of the zoom system have been described. The proposed two-element zoom system consisting of a system of two lenses with variable focal lengths maintains a constant distance between the object and image planes and fixed position of both lenses during zooming. The basic parameters and third-order aberration coefficients of such a system are calculated using an example.
3D imaging with large range dynamics and simultaneous accurate speed measurement
Authors: Feneyrou Patrick , Martin Aude , Dolfi Daniel , Payot Etienne
Published: June 2024

In this paper, we describe 3D imaging experiments performed using a frequency modulated continuous wave (FMCW) LIDAR. A detailed study of noise and signal statistics is provided in order to analyze the sensitivity of our FMCW LIDAR, and its capability to image complex scenes over a broad range (up to 3 km) is demonstrated. An image example is also given to illustrate that simultaneous measurement of the speed for each pixel gives additional information that can be used to help segmentation algorithms and target classification. Although 3D imaging using the FMCW system has already been demonstrated, the demonstrated range is generally limited to a few 100 m. In this paper, 3D imaging up to 3 km is achieved while preserving compactness and ruggedness to the various environmental conditions.
Applied optics research at Zhejiang University–College of Optical Science and Engineering: Introduction to the feature issue
Authors: Dong Liu , Cuifang Kuang
Published: June 2024

This institutional focus issue provides a small glimpse into the depth and breadth of
innovative optical engineering research taking place today at Zhejiang
University–College of Optical Science and Engineering
(ZJU-COSE).
Propagation properties of a partially coherent Laguerre–Gaussian beam with multiple off-axis vortex phases
Authors: Zhang Xing-Yu , Xu Hua-Feng
Published: June 2024

In this paper, a new theoretical model of a partially coherent Laguerre–Gaussian (LG) beam carrying multiple off-axis vortex phases was established. The evolution properties of the focused intensity of the beam after passing through a thin lens were theoretically studied, and then the modulation effect of multiple off-axis vortex phases on the beam with multiring structured intensity was explored. The results indicate that the multiple off-axis vortex phases can reconstruct the multiring structured intensity within the LG beam, thus generating a structured intensity with multilobe and multiring patterns. What is more, the intensity distribution of the lobes between two adjacent rings is complementary, and its number is related to the number and topological charge of off-axis vortex phases. However, with a decrease in the coherence, such a multilobe and multiring structured intensity distribution disappears, gradually evolves into a polygonal flat-topped distribution, and finally degenerates into a quasi-Gaussian distribution. This work demonstrates the effective regulation of multiple off-axis vortex phases on a beam with a multiring structured intensity and indicates that regulating the multiple off-axis vortices provides an additional degree of freedom for optical field modulation, which will have potential applications in the fields of optical micromanipulation and optical information storage.
Hyperspectral dark-field optical microscopy correlated to atomic force microscopy for the analysis of single plasmonic nanoparticles: tutorial
Authors: Abadie Claire , Liu Mingyang , Prado Yoann , Pluchery Olivier
Published: June 2024

Plasmonic nanostructures are actively investigated for their optical properties and for a wide range of applications in nanophotonics, biosensing, photocatalysis, hot carrier physics, and advanced cancer therapies. The localized surface plasmon resonance (LSPR) can be excited in gold or silver nanoparticles or in more complex nanostructures and gives rise to a wide range of unique optical properties. It is often critical to be able to localize individual plasmonic nanoparticles and simultaneously measure their spectrum. This is known as hyperspectral microscopy. In this tutorial, we describe and carefully explain how to achieve this goal with an optical microscope equipped with a dark-field objective and an optical spectrometer. The images and the scattering spectra of spherical gold nanoparticles with diameters of 90, 70, 50, and 25 nm are recorded. We compare them with the scattering spectra predicted with the Mie formula (LSPR peaks measured at 553, 541, 535, and 534 nm, respectively). The optical images are limited by the diffraction, and this is discussed in the framework of the Abbe equation. We also describe a strategy to easily correlate the optical images with atomic force microscope images of the samples. This allows us to precisely relate the morphology of the nanoparticles with their optical images, their color, and their optical spectrum. The case of non-spherical nanostructures, namely, dimers of nanoparticles, is also discussed. This approach allows a relatively low-cost setup and efficient characterization method that will be helpful for teachers who want to introduce their students to the wide topics of plasmonics. This will also be useful for labs seeking an affordable method to investigate the plasmonic properties of single nanostructures.
Multi-hop fault-tolerant teleportation of arbitrary two-qubit states with cluster channel
Authors: Meng TianTian , Wei YuZhen , Chen Hong , Huang Xu , Jiang Min
Published: June 2024

In this paper, we propose one multi-hop fault-tolerant teleportation scheme leveraging non-maximally entangled cluster states as the quantum channel, which is crucial for efficient transmission over extended distances. During quantum communication, environmental noise may introduce operational errors between adjacent nodes. In order to uphold the maximum transmission efficiency, error correction operations are exclusively conducted by the ultimate receiver rather than intermediate nodes. Error outcomes from each node can be synchronously relayed to the receiver via the classical channel, effectively diminishing the delays and operational intricacies, thereby significantly bolstering the transmission efficiency. Moreover, we utilize the Quirk simulation software to simulate the teleportation process.
Enhancement of terahertz fields in LiTaO3 waveguides using a conical pulse front
Authors: Sung Eric R. , Kai Yun , Pezeril Thomas , Nelson Keith A.
Published: June 2024

The development of methods for the generation of strong ultrafast electromagnetic pulses in the terahertz (THz) spectral range has led to a surge of progress in nonlinear THz spectroscopy and THz control of molecular and collective responses. For spectroscopy in the 1-THz range, the submillimeter wavelengths and associated large spot sizes, large optical elements, and short distances between final focusing elements and samples can lead to cumbersome experimental setups that are incompatible with some sample environments. Here, we introduce a novel terahertz ring excitation (TREx) optical pumping geometry to generate superposing, focusing fields in planar THz waveguides made out of the electro-optic material lithium tantalate. High THz fields, >175 kV/cm, are generated and measured optically with no free-space THz propagation. The field level achieved by pumping with a sequence of concentric rings of excitation light exceeds by about 20× the result of a single cylindrically focused line of pump light that has been used routinely in previous work. The technique opens new prospects for compact waveguide-based linear and nonlinear THz spectroscopy and signal processing.
Enhancing single-pixel imaging reconstruction using hybrid transformer network with adaptive feature refinement
Authors: Lim JiaYou , Chiew YeongShiong , Phan Raphaël C.-W. , Chong Edwin K.-P. , Wang Xin
Published: June 2024

Single-pixel imaging (SPI) is a novel imaging technique that applies to acquiring spatial information under low light, high absorption, and backscattering conditions. The existing reconstruction techniques, such as pattern analysis and signal-recovery algorithms, are inefficient due to their iterative behaviors and substantial computational requirements. In this paper, we address these issues by proposing a hybrid convolutional-transformer network for efficient and accurate SPI reconstruction. The proposed model has a universal pre-reconstruction layer that can reconstruct the single-pixel measurements collected using any SPI method. Moreover, we utilize the hierarchical encoder-decoder network in U-Net architectures and employ the proposed CONText AggregatIon NEtwoRk (Container) as the adaptive feature refinement module to adaptively leverage the significance of globally and locally enhanced features in SPI reconstruction. As such, we can improve the conventional SPI methods in terms of reconstruction speed and accuracy. Extensive experiments show that the proposed model achieve a significant performance improvement as compared to traditional SPI methods digitally and experimentally while increasing the reconstruction frame rates by threefold. Moreover, the proposed model also outperforms state-of-the-art deep learning models in performing single-pixel imaging reconstruction.
Outage-guaranteed transmission for IRS-assisted FSO systems
Authors: Chen Baojun , Zhu Xiaodong
Published: June 2024

Intelligent reflecting surface (IRS)-assisted free space optical (FSO) communication can overcome line-of-sight and bring spatial diversity, which is considered to be a good complement to direct FSO links. This paper is interested in understanding the role of IRS-assisted FSO links when coexisting with direct FSO links. Due to the diverse nature of existing FSO channel models and the reliability requirements of IRS-assisted FSO systems, this paper aims to investigate the transmission problems of link selection and power configuration under the quality of service guarantee for link outage, which can be applicable to different channel models. Despite the inherent complexity of the problems, transmission schemes, i.e., sum rate transmission (SRT) and rate fairness transmission (RFT) are developed, which can achieve the respective optimal performance. Also, some insights for transmission schemes are provided. The results verify the efficacy of the proposed transmission schemes. The performance of the system may be improved by 40% and 41% for SRT and RFT, respectively.
Combined axicon design based on a structural parameter optimization algorithm
Authors: Cui Zongyu , Ren Jiaojiao , Zhang Jiyang , Zhang Dandan , Gu Jian , Xue Junwen , Li Lijuan
Published: June 2024

This study proposes a combined axicon (CA) design method based on a structural parameter optimization algorithm designed to rapidly address the demands of practical application scenarios, precisely tailor structural parameters, and produce high-quality Bessel beams (HQ-QBBs) that satisfy specific requirements. Compared to generating an HQ–QBB using an axicon, our method effectively overcomes the shortcomings of fewer tunable factors, a large number of high-energy side-lobes, and limited non-diffractive regions. Through detailed analyses of the transmission characteristics, imaging characteristics, and thick-sample detection ability of the generated HQ-QBB, the significant advantages of the proposed method are demonstrated. The proposed method is not only relevant to current research but also demonstrates wide-ranging application potential in future lens designs.
Nanoradians level high resolution autocollimation method based on array slits
Authors: Yu Yang , Li Yuechao , Zhang Weixuan , Zhang Yunhan , Tan Jiubin
Published: June 2024

This study developed a detailed mathematical model to elucidate array slits imaging and linear CCD acquisition. Frequency domain analysis revealed the relationship between system parameters and spot image aliasing noise. Aliasing noise was reduced through optimized array slits design and linear CCD parameter selection, improving angular measurement resolution and stability. Unlike in traditional methods, only 8 array slits were required to achieve nanoradian-level resolution and stability. The device achieved an angular measurement resolution of 0.0005 arcsec over a measurement range of ±400 arcsec. Static repeatability is 0.0003 arcsec, and stability is 0.0061 arcsec in 2 hours.
Automatic detection of face mask wearing based on polarization imaging
Authors: Li Bosong , Li Yahong , Li Kexian , Fu Yuegang , Ouyang Mingzhao , Jia Wentao
Published: June 2024

Amidst the global health crisis sparked by the coronavirus pandemic, the proliferation of respiratory illnesses has captured worldwide attention. An increasing number of individuals wear masks to mitigate the risk of viral transmission. This trend has posed a critical challenge for the development of automatic face mask wearing detection systems. In response, this paper proposed what we believe is a novel face mask wearing detection framework DOLP-YOLOv5, which innovatively employs polarization imaging to enhance the detection of face mask by leveraging the unique characteristics of mask surfaces. For extracting essential semantic details of masks and diminish the impact of background noise, the lightweight shuffle attention (SA) mechanism is integrated in the backbone. Further, a Content-Aware Bidirectional Feature Pyramid Network (CA-BiFPN) is applied for feature fusion, sufficiently integrating the information at each stage and improving the ability of the feature presentation. Moreover, Focal-EIoU loss is utilized for the bounding box regression to improve the accuracy and efficiency of detection. Benchmark evaluation is performed on the self-constructed polarization face mask (PFM) dataset compared with five other mainstream algorithms. The mAP50-95 of DOLP-YOLOv5 reached 63.5%, with 3.08% and 4.44% improvements over the YOLOv8s and YOLOv9s, and achieved a response speed of 384.6f/s. This research not only demonstrates the superiority of DOLP-YOLOv5 in face mask wearing detection, but also has certain reference significance for other detection of polarization imaging.
Large-size PVG-based waveguide simulation and uniformity optimization for AR-HUD
Authors: Wei Ran , Yang Canran , Wang Chuang , Zhang JieYi , Wang Wei , Gu Yuchen , Lin Nan , Pan Xusheng , Zhou Weiqi , Weng Yishi , Zhang Yuning
Published: June 2024

Polarization volume grating (PVG), a kind of diffractive optical element, is applied widely for augmented reality (AR) near-eye display (NED) lately. However, PVG-based AR head-up display (AR-HUD) requires a large-size exit pupil and uniform efficiency, and there is presently no systematic simulation method for this type of application. Here, we introduce a unique simulation analysis method via the large-size PVG-based waveguide technology for AR-HUD. Through the self-built particle swarm optimization (PSO) algorithm, on the waveguide structure of 290 mm × 160 mm × 3 mm, with an eyerelief distance of 600 mm, the binocular field of view uniformity reaches 35.37% at an eye box of 100 mm × 50 mm, and the monocular uniformity can reach 31.65% and 32.48% respectively. The design scheme in this paper provides guidance for the large-size diffractive waveguide display for AR-HUD.
638-nm laser-diode pumped alexandrite femtosecond laser passively mode-locked by single-walled carbon nanotubes
Authors: Cai Enlin , Zhang Shuaiyi , Jiang Meng , Liu Qiang , Lou Fei , Lv Hao , Li Tao
Published: June 2024

A passively mode-locked alexandrite laser was developed with a single-walled carbon nanotubes (SWCNTs) saturable absorber (SA), which was pumped by a 638 nm red laser. After using a pair of prisms for dispersion compensation, the narrowest pulse width of 70 fs was achieved at a repetition rate of 100 MHz. The mode-locked laser had a signal-to-noise ratio greater than 55 dB and a beam quality factor of less than 1.13. A high average output power of 386 mW was achieved with a slope efficiency of 12.4%. It is the first time a passively mode-locked alexandrite femtosecond laser pumped by a 638 nm red laser has been developed. Moreover, it is also the first time that SWCNTs are used as SAs to achieve a passively mode-locked laser in the visible light range.
Distributed Bragg reflector based ASE noise removal pump wavelength filters for futuristic chip-scale quantum photonic circuits
Authors: Priyadarshini Pratyasha , Goswami Arnab , Velamuri Ashitosh , Krishna Das Bijoy
Published: June 2024

This article reports a novel design of a compact tunable resonance filter with a highly extinguished and ultra-broad out-of-band rejection for on-chip amplified spontaneous noise suppression from pump lasers highly demanding for generating pure/entangled photon pairs via χ(3) process in a CMOS compatible silicon photonics technology platform. The proposed device is designed with two identically apodized distributed grating structures for guided Fabry-Perot resonant transmissions in a silicon-on-insulator rib waveguide structure. The device design parameters are optimized by theoretical simulation for a low insertion loss singly-resonant transmission peak at a desired wavelength. We observed that a device length of as low as ∼ 35 µm exhibits a rejection band as large as ∼ 60 nm with an extinction of ∼ 40 dB with respect to the resonant wavelength peak at λ
r
 ∼ 1550 nm (FWHM ∼ 80 pm, IL ∼ 2 dB). The experimental results have been shown to be closely matching to our theoretical simulation and modeling results in terms of its stop bandwidth and resonance wavelength for noise suppressed pump laser wavelength filtering. As expected from the theoretical prediction, the trend pertaining to the trade-off between passive insertion loss and Q-value of the resonances has been observed depending on the device parameters. The thermo-optic tuning characteristics of resonant wavelengths have been obtained by integrating microheaters. The resonance peak could be tuned at a rate of 96 pm per mW of consumed thermal power. Noise associated with an amplified pump wavelength (λ
P
∼ 1550 nm) has been shown to be suppressed (∼ 40-dB), up to the detector noise floor.
Pound–Drever–Hall feedforward: laser phase noise suppression beyond feedback
Authors: Chao Yu-Xin , Hua Zhen-Xing , Liang Xin-Hui , Yue Zong-Pei , You Li , Khoon Tey Meng
Published: June 2024

Pound–Drever–Hall (PDH) laser frequency stabilization is a powerful technique widely used for building narrow linewidth lasers. This technique is, however, ineffective in suppressing high-frequency (>100kHz) laser phase noise detrimental for many applications. Here, we introduce an effective method that can greatly enhance its high-frequency performance. The idea is to recycle the residual PDH signal of a laser locked to a cavity by feedforwarding it directly to the laser output field after a delay fiber. Using this straightforward method, we demonstrate a phase noise suppression capability about four orders of magnitude better than just using the usual PDH feedback for noise around a few MHz. We further find that this method exhibits noise suppression performance equivalent to cavity filtering. This method holds great promise for applications demanding highly stable lasers with diminished phase noise up to tens of MHz (e.g., precise and high-speed control of atomic and molecular quantum states).
Mendelian segregation and high recombination rates facilitate genetic analyses in Cryptosporidium parvum
Authors: Kimball Abigail , Funkhouser-Jones Lisa , Huang Wanyi , Xu Rui , Witola William H. , Sibley L. David
Published: June 2024

Very little is known about the process of meiosis in the apicomplexan parasite Cryptosporidium despite the essentiality of sex in its life cycle. Most cell lines only support asexual growth of Cryptosporidium parvum (C. parvum), but stem cell derived intestinal epithelial cells grown under air-liquid interface (ALI) conditions support the sexual cycle. To examine chromosomal dynamics during meiosis in C. parvum, we generated two transgenic lines of parasites that were fluorescently tagged with mCherry or GFP on chromosomes 1 or 5, respectively. Infection of ALI cultures or Ifngr1-/- mice with mCherry and GFP parasites resulted in cross-fertilization and the formation of “yellow” oocysts, which contain 4 haploid sporozoites that are the product of meiosis. Recombinant oocysts from the F1 generation were purified and used to infect HCT-8 cultures, and phenotypes of the progeny were observed by microscopy. All possible phenotypes predicted by independent segregation were represented equally (~25%) in the population, indicating that C. parvum chromosomes exhibit a Mendelian inheritance pattern. The most common pattern observed from the outgrowth of single oocysts included all possible parental and recombinant phenotypes derived from a single meiotic event, suggesting a high rate of crossover. To estimate the frequency of crossover, additional loci on chromosomes 1 and 5 were tagged and used to monitor intrachromosomal crosses in Ifngr1−/− mice. Both chromosomes showed a high frequency of crossover compared to other apicomplexans with map distances (i.e., 1% recombination) of 3–12 kb. Overall, a high recombination rate may explain many unique characteristics observed in Cryptosporidium spp. such as high rates of speciation, wide variation in host range, and rapid evolution of host-specific virulence factors.
Escherichia coli adaptation under prolonged resource exhaustion is characterized by extreme parallelism and frequent historical contingency
Authors: Zion Shira , Katz Sophia , Hershberg Ruth
Published: June 2024

Like many other non-sporulating bacterial species, Escherichia coli is able to survive prolonged periods of resource exhaustion, by entering a state of growth called long-term stationary phase (LTSP). In July 2015, we initiated a set of evolutionary experiments aimed at characterizing the dynamics of E. coli adaptation under LTSP. In these experiments populations of E. coli were allowed to initially grow on fresh rich media, but were not provided with any new external growth resources since their establishment. Utilizing whole genome sequencing data obtained for hundreds of clones sampled at 12 time points spanning the first six years of these experiments, we reveal several novel aspects of the dynamics of adaptation. First, we show that E. coli continuously adapts genetically, up to six years under resource exhaustion, through the highly convergent accumulation of mutations. We further show that upon entry into LTSP, long-lasting lineages are established. This lineage structure is in itself convergent, with similar lineages arising across independently evolving populations. The high parallelism with which adaptations occur under LTSP, combined with the LTSP populations’ lineage structure, enable us to screen for pairs of loci displaying a significant association in the occurrence of mutations, suggestive of a historical contingency. We find that such associations are highly frequent and that a third of convergently mutated loci are involved in at least one such association. Combined our results demonstrate that LTSP adaptation is characterized by remarkably high parallelism and frequent historical contingency.
Women’s participation in household decision-making: Qualitative findings from the Shonjibon Trial in rural Bangladesh
Authors: Kirkwood Elizabeth K. , Khan Jasmin , Hasan Mohammad Mehedi , Iqbal Afrin , Tahsina Tazeen , Huda Tanvir , Hoddinott John Frederick , Laba Tracey Lea , Muthayya Sumithra , Goodwin Nicholas , Islam Munirul , Kingsley Emwinyore Agho , Arifeen Shams E. , Dibley Michael J. , Alam Neeloy Ashraful
Published: June 2024

A key element of women’s empowerment is the ability to participate in household decision-making. This study presents the qualitative results from the Shonjibon Cash and Counselling Trial baseline process evaluation with the aim of exploring the status of women’s decision-making at the trial’s outset and to facilitate the exploration of any changes in women’s empowerment over the course of the trial. Between January and March 2021, we conducted forty-one in-depth interviews with pregnant women in rural Bangladesh. The research team translated, transcribed, coded, and discussed the interviews. We used thematic analysis to examine women’s experience and perceptions on household decision-making. The key findings that emerged; women jointly participated in financial decision-making with their husbands; men made the final decision regarding seeking healthcare, and women solely made choices regarding infant and young child feeding. Our findings revealed that women felt that they needed to discuss their plans to go outside the house with their husbands, many perceived a lack of importance in the community towards women’s participation in decision-making. This study documents current contextual information on the status of women’s involvement in household decision-making and intrahousehold power dynamics at the start of the Shonjibon Cash and Counselling Trial.
Global biochemical profiling of fast-growing Antarctic bacteria isolated from meltwater ponds by high-throughput FTIR spectroscopy
Authors: Akulava Volha , Tafintseva Valeria , Blazhko Uladzislau , Kohler Achim , Miamin Uladzislau , Valentovich Leonid , Shapaval Volha
Published: June 2024

Fourier transform infrared (FTIR) spectroscopy is a biophysical technique used for non-destructive biochemical profiling of biological samples. It can provide comprehensive information about the total cellular biochemical profile of microbial cells. In this study, FTIR spectroscopy was used to perform biochemical characterization of twenty-nine bacterial strains isolated from the Antarctic meltwater ponds. The bacteria were grown on two forms of brain heart infusion (BHI) medium: agar at six different temperatures (4, 10, 18, 25, 30, and 37°C) and on broth at 18°C. Multivariate data analysis approaches such as principal component analysis (PCA) and correlation analysis were used to study the difference in biochemical profiles induced by the cultivation conditions. The observed results indicated a strong correlation between FTIR spectra and the phylogenetic relationships among the studied bacteria. The most accurate taxonomy-aligned clustering was achieved with bacteria cultivated on agar. Cultivation on two forms of BHI medium provided biochemically different bacterial biomass. The impact of temperature on the total cellular biochemical profile of the studied bacteria was species-specific, however, similarly for all bacteria, lipid spectral region was the least affected while polysaccharide region was the most affected by different temperatures. The biggest temperature-triggered changes of the cell chemistry were detected for bacteria with a wide temperature tolerance suchPseudomonas lundensisstrains andAcinetobacter lwoffiiBIM B-1558.
Mathematical modeling and performance evaluation of Ducted Horizontal-axis Helical Wind Turbines: Insights into aerodynamics and efficiency
Authors: Shaikh Zishan , Fazlizan Ahmad , Razali Halim , Wong Kok Hoe , Molla Altaf Hossain , Abdulkadir Rabiu Aliyu , Baleanu Dumitru , Ibrahim Rabha W.
Published: June 2024

With the escalating demand for energy, there is a growing focus on decentralized, small-scale energy infrastructure. The success of new turbines in this context is notable. However, many of these turbines do not follow many of the basic ideas established to evaluate their performance, leaving no precise technique or mathematical model. This research developed a Ducted Horizontal-axis Helical Wind Turbine (DHAHWT). The DHAHWT is a duct-mounted helical savonius turbine with a venturi and diffuser to improve flow. Unlike a vertical axis helical savonius turbine, DHAHWT revolves roughly parallel to the wind, making it a horizontal turbine. This complicates mathematical and theoretical analysis. This study created a DHAHWT mathematical model. COMSOL simulations utilizing Menter’s Shear Stress Transport model (SST) across an incoming velocity range of 1m/s to 4m/s were used to evaluate the turbine’s interaction with the wind. MATLAB was used to train an artificial neural network (ANN) utilizing COMSOL data to obtain greater velocity data. The Mean Average Percentage Error (MAPE) and Root Mean Square Error (RMSE) of ANN data were found to be 3%, indicating high accuracy. Further, using advanced statistical methods the Pearson’s correlation coefficient was calculated resulting in a better understanding of the relationship of between incoming velocity and velocity at different sections of the wind turbine. This study will shed light on the aerodynamics and working of DHAHWT.
Situational context of home-based sexual education in urban slums of Ibadan, Nigeria–evidence from a qualitative study
Authors: Aliyu Taofeek Kolawole
Published: June 2024

This study explores the influence of situational context on parent-adolescent communication about sexual and reproductive health (SRH) issues in the urban slums of Ibadan, Nigeria. A qualitative exploratory study was conducted in the Southeast and Northeast LGAs of Ibadan. Eight (8) vignette-based focus group discussions (FGDs) with parents and adolescents of both sexes were conducted in addition to four (4) key informant interviews (KIIs) with community and women’s leaders. Interviews were tape-recorded, transcribed, and translated into English. Thematic analysis was adopted using ATLAS Ti 9 software. Findings portray SRH meanings and experiences, intergenerational cultural norms, and expectations for SRH, gender double standards in SRH discussion, streetwise SRH knowledge, and social media exposure as contexts that interfere with parent-adolescent communication on SRH issues. The findings show that despite understanding the need for SRH discussion, parents and adolescents lack effective communication on SRH issues due to the interference of unfiltered streetwise SRH knowledge and social media exposure. Also, SRH conversation between parents and adolescents promotes gender inequalities as different information is passed to adolescent girls and boys. Interventions that take into account situational occurrences must be geared towards enabling parents to give their adolescents early exposure to relevant, context-specific SRH knowledge.
Deep graph contrastive learning model for drug-drug interaction prediction
Authors: Jiang Zhenyu , Gong Zhi , Dai Xiaopeng , Zhang Hongyan , Ding Pingjian , Shen Cong
Published: June 2024

Drug-drug interaction (DDI) is the combined effects of multiple drugs taken together, which can either enhance or reduce each other’s efficacy. Thus, drug interaction analysis plays an important role in improving treatment effectiveness and patient safety. It has become a new challenge to use computational methods to accelerate drug interaction time and reduce its cost-effectiveness. The existing methods often do not fully explore the relationship between the structural information and the functional information of drug molecules, resulting in low prediction accuracy for drug interactions, poor generalization, and other issues. In this paper, we propose a novel method, which is a deep graph contrastive learning model for drug-drug interaction prediction (DeepGCL for brevity). DeepGCL incorporates a contrastive learning component to enhance the consistency of information between different views (molecular structure and interaction network), which means that the DeepGCL model predicts drug interactions by integrating molecular structure features and interaction network topology features. Experimental results show that DeepGCL achieves better performance than other methods in all datasets. Moreover, we conducted many experiments to analyze the necessity of each component of the model and the robustness of the model, which also showed promising results. The source code of DeepGCL is freely available athttps://github.com/jzysj/DeepGCL.
Impact of QRS misclassifications on heart-rate-variability parameters (results from the CARLA cohort study)
Authors: Sauerbier Frank , Haerting Johannes , Sedding Daniel , Mikolajczyk Rafael , Werdan Karl , Nuding Sebastian , Greiser Karin H. , Swenne Cees A. , Kors Jan A. , Kluttig Alexander
Published: June 2024

Background

Heart rate variability (HRV), an important marker of autonomic nervous system activity, is usually determined from electrocardiogram (ECG) recordings corrected for extrasystoles and artifacts. Especially in large population-based studies, computer-based algorithms are used to determine RR intervals. The Modular ECG Analysis System MEANS is a widely used tool, especially in large studies. The aim of this study was therefore to evaluate MEANS for its ability to detect non-sinus ECG beats and artifacts and to compare HRV parameters in relation to ECG processing. Additionally, we analyzed how ECG processing affects the statistical association of HRV with cardiovascular disease (CVD) risk factors.

Methods

20-min ECGs from 1,674 subjects of the population-based CARLA study were available for HRV analysis. All ECGs were processed with the ECG computer program MEANS. A reference standard was established by experienced clinicians who visually inspected the MEANS-processed ECGs and reclassified beats if necessary. HRV parameters were calculated for 5-minute segments selected from the original 20-minute ECG. The effects of misclassified typified normal beats on i) HRV calculation and ii) the associations of CVD risk factors (sex, age, diabetes, myocardial infarction) with HRV were modeled using linear regression.

Results

Compared to the reference standard, MEANS correctly classified 99% of all beats. The averaged sensitivity of MEANS across all ECGs to detect non-sinus beats was 76% [95% CI: 74.1;78.5], but for supraventricular extrasystoles detection sensitivity dropped to 38% [95% CI: 36.8;38.5]. Time-domain parameters were less affected by false sinus beats than frequency parameters. Compared to the reference standard, MEANS resulted in a higher SDNN on average (mean absolute difference 1.4ms [95% CI: 1.0;1.7], relative 4.9%). Other HRV parameters were also overestimated as well (between 6.5 and 29%). The effect estimates for the association of CVD risk factors with HRV did not differ between the editing methods.

Conclusion

We have shown that the use of the automated MEANS algorithm may lead to an overestimation of HRV due to the misclassification of non-sinus beats, especially in frequency domain parameters. However, in population-based studies, this has no effect on the observed associations of HRV with risk factors, and therefore an automated ECG analyzing algorithm as MEANS can be recommended here for the determination of HRV parameters.