bluuebunny/crossref_metadata_2025 huggingface dataset:
Intranasal delivery of PEA-producing Lactobacillus paracasei F19 alleviates SARS-CoV-2 spike protein-induced lung injury in mice
Authors: Del Re Alessandro , Franzin Silvia Basili , Lu Jie , Palenca Irene , Zilli Aurora , Pepi Federico , Troiani Anna , Seguella Luisa , Pesce Marcella , Esposito Giovanni , Sarnelli Giovanni , Esposito Giuseppe
Published: March 2024

Background

SARS-CoV-2 belongs to the coronaviridae family and infects human cells by directly interacting with the angiotensin-converting enzyme-2 (ACE-2) through the viral Spike Protein (SP). While vaccines are crucial, much attention has been directed towards managing the symptoms of acute respiratory distress syndrome. Our present study highlights the potential in counteracting lung inflammation triggered by SARS-CoV-2 SP of the intranasal administration of the engineered probiotic Lactobacillus paracasei F19 expressing the enzyme NAPE-PLD (pNAPE-LP) able to in situ release palmitoylethanolamide (PEA) under a super-low boost of palmitate.

Methods

C57BL/6J mice undergo prophylactic treatment with intranasal pNAPE-LP/palmitate for 7 days before a 7 days challenge with intranasal SARS-CoV-2 SP. Then the capability of pNAPE-LP of colonizing the lungs and actively release PEA in situ have been determined by immunofluorescence, western blot and HPLC-MS. Moreover, the innate immune system downregulation and the histological damage rescue exerted by pNAPE-LP have been tested by immunofluorescence, hematoxylin and eosin staining, western blot analysis and ELISA test for the release of the pro-inflammatory mediators.

Results

pNAPE-LP effectively colonizes mice lungs and releases the anti-inflammatory compound PEA. Moreover, pNAPE-LP exhibits a protective effect on alveolar morphology, innate immune cells infiltration and in the reduction of neutrophil count, effectively reducing lung injury induced by SARS-CoV-2 SP. This is achieved by mitigating TLR4-mediated NLRP3 activation and the downstream pro-inflammatory products such as ILs, TNFα, C-reactive protein and the myeloperoxidase activity. Interestingly we observed a global reduction ACE2 expression in the lungs.

Conclusion

pNAPE-LP actively protect from severe inflammatory-related symptoms in SP-challenged mice. Also, it can downregulate the expression of ACE-2 receptors at the lung site potentially preventing the spreading of the infection.
Singleton-based species names and fungal rarity: Does the number really matter?
Authors: Cazabonne Jonathan , Walker Allison K. , Lesven Jonathan , Haelewaters Danny
Published: March 2024

Fungi are among the least known organisms on earth, with an estimated number of species between 1.5 and 10 million. This number is expected to be refined, especially with increasing knowledge about microfungi in undersampled habitats and increasing amounts of data derived from environmental DNA sequencing. A significant proportion of newly generated sequences fail to match with already named species, and thus represent what has been referred to as fungal “dark taxa”. Due to the challenges associated with observing, identifying, and preserving sporophores, many macro- and microfungal species are only known from a single collection, specimen, isolate, and/or sequence—a singleton. Mycologists are consequently used to working with “rare” sequences and specimens. However, rarity and singleton phenomena lack consideration and valorization in fungal studies. In particular, the practice of publishing new fungal species names based on a single specimen remains a cause of debate. Here, we provide some elements of reflection on this issue in the light of the specificities of the fungal kingdom and global change context. If multiple independent sources of data support the existence of a new taxon, we encourage mycologists to proceed with formal description, irrespective of the number of specimens at hand. Although the description of singleton-based species may not be considered best practice, it does represent responsible science in the light of closing the Linnean biodiversity shortfall.
Container buildings used for residential and business purposes in Johannesburg, South Africa and potential heat-related health risks
Authors: Mfamadi Tanganedzeni , Chivimbo Kimberley , Mogadime Philistase , Bidassey-Manilal Shalin , Kapwata Thandi , Naidoo Natasha , Wright Caradee Y
Published: March 2024

Background Outdoor and indoor air temperature affects human health and wellbeing. Climate change projections suggest that global temperatures will continue to increase, and this poses a threat to health. Buildings (for housing and business purposes) that can protect humans from the adverse effects of temperature is essential, especially in the context of climate change. Method In this cross-sectional study, we measured indoor temperature inside shipping containers comprising a seven-storey block of apartments and businesses in Johannesburg, South Africa for 14 days. We assessed indoor temperature and relative humidity; evaluated measured temperatures in relation to thresholds known to be associated with adverse health risks; and sought to understand heat-health perceptions and symptoms of people living and working in shipping container units. Results Median indoor apparent temperature (AT) (a combination of temperature and relative humidity) was 16 °C with values ranging from 6 °C (observed at 8:00) to 42 °C (observed at 17:00). Insulated units had temperatures between 2°C and 9°C cooler than the uninsulated unit. Heat-health risks from AT exposure were likely in all units, although there was variation in the number of occurrences that AT measurements exceeded the four symptom bands of caution, extreme caution, danger and extreme danger. Some participants believed that their units were hot during hot weather and most people opened windows or did nothing during hot weather. Few participants reported experiencing adverse heat-health impacts, except for experiencing headaches (58%) and feeling tired or weak (40%). Conclusion Residents, tenants, or business owners using shipping containers should consider insulation installation and adequate windows/air conditioning for ventilation, especially in hot climates. Further research and awareness regarding heat-health risks of living or working in these spaces is needed.
Study of thyroid disorders in pregnancy and their effects on feto-maternal outcomes
Authors: Joshi Jalormy , Tembhare Amardeep
Published: March 2024

The second most common endocrine disease that occurs during pregnancy is thyroid disease. Overt and subclinical thyroid dysfunction can lead to adverse effects on both the fetus and the mother. Thyroid diseases during pregnancy affect maternal outcomes and neuropsychological development of the fetus. The objectives of this study were to investigate the effects of thyroid disorders on maternal health and its maternal and perinatal outcomes and to formulate a plan for the management of thyroid disorders in pregnancy. This prospective observational study involved 165 pregnant women. They will be assessed using thyroid function tests, and patients with deranged thyroid function will be treated and followed up. Pregnancy and outcomes were recorded. The findings of this research will offer important new information regarding possible side effects linked to thyroid issues in mothers as well as the clear advantages of therapy. Maternal thyroid diseases have several risk factors in addition to clear advantages of treatment.
Towards a computational history of modernism in European literary history: Mapping the Inner Lives of Characters in the European Novel (1840–1920)
Authors: Radak Tamara , Burnard Lou , Francois Pieter , Hilger Agnes , Jannidis Fotis , Palkó Gábor , Patras Roxana , Preminger Michael , Santos Diana , Schöch Christof
Published: March 2024

In this paper, we investigate the common narrative in literary history that the inner lives of characters became a central preoccupation of literary modernism – a phenomenon commonly referenced as the “inward turn”. We operationalize this notion via a proxy, tracing the use of verbs relating to inner life across 10 language corpora from the ELTeC collection, which comprises novels from the period between 1840–1920. We expected to find an increase in the use of inner-life verbs corresponding to the traditional periodisation of modernism in each of the languages. However, different experiments conducted with the data do not confirm this hypothesis. We therefore look at the results in a number of more granular ways, but we cannot identify any common trends even when we split the verbs into individual categories, or take canonicity or gender into account. We discuss the obtained results in detail, proposing potential reasons for them and including potential avenues of further research as well as lessons learned.
Characterizing developing executive functions in the first 1000 days in South Africa and Malawi: The Khula Study
Authors: Zieff Michal R , Miles Marlie , Mbale Emmie , Eastman Emma , Ginnell Lorna , Williams Steven C R , Jones Derek K , Alexander Daniel C , Wijeratne Peter A. , Gabard-Durnam Laurel J , Klepac-Ceraj Vanja , Bonham Kevin S , Pini Nicolò , Sania Ayesha , Lucchini Maristella , Deoni Sean , Fifer William P , Gladstone Melissa , Amso Dima , Donald Kirsten A
Published: March 2024

The term ‘executive functions’ (EFs) refers to a set of skills that support flexible control over thought and action. Classic EFs (working memory, inhibitory control, and cognitive flexibility) do not show measurable stable function until after the third year of life and continue to develop into early adulthood. However, even at the earliest ages, these EFs are shown to have value for predicting school readiness and academic achievement. They continue to have predictive value for success, mental health, and general well-being across the lifespan including in ageing populations. As such, understanding the developing brain and cognitive developmental dynamics that set the stage for the development of EFs, in the first three years of life, is crucial for developing programming that supports healthy EFs development. The goal of this manuscript is to describe the goals, hypotheses, participant populations, and methodology of the Khula Study. Khula is a multi-modal multi-site longitudinal birth cohort study designed to characterise emerging EFs in the first 1000 days of life in global majority settings. Most research to date has been conducted in highincome countries rather than low- and middle-income countries that comprise most of the world’s child population. We assert that understanding and supporting EF development has global importance, but this must be done with the understanding that EFs are skills that develop within the context of adaptation to one’s environment. As such, the Khula Study aims to understand which EF influences are common across cultures but also which are culture specific. We will address these questions by incorporating data from South Africa and Malawi to understand influences on EF development and outcomes for children living in these contexts. We enrolled 394 mothers (84% antenatally) from Gugulethu in Cape Town, South Africa and 507 mothers (42% antenatally) from Blantyre, Malawi.
The genome sequence of the Orange-tailed Clearwing, Synanthedon andrenaeformis (Laspeyres, 1801)
Authors: Boyes Douglas , Holland Peter W.H. ,   University of Oxford and Wytham Woods Genome Acquisition Lab,   Darwin Tree of Life Barcoding collective,   Wellcome Sanger Institute Tree of Life Management, Samples and Laboratory team,   Wellcome Sanger Institute Scientific Operations: Sequencing Operations,   Wellcome Sanger Institute Tree of Life Core Informatics team,   Tree of Life Core Informatics collective,   Darwin Tree of Life Consortium
Published: March 2024

We present a genome assembly from an individual male Synanthedon andrenaeformis (the Orange-tailed Clearwing; Arthropoda; Insecta; Lepidoptera; Sesiidae). The genome sequence is 348.4 megabases in span. Most of the assembly is scaffolded into 31 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 16.65 kilobases in length. Gene annotation of this assembly on Ensembl identified 12,867 protein coding genes.
The genome sequence of strawberry clover, Trifolium fragiferum L. (Fabaceae)
Authors: Mian Sahr , Christenhusz Maarten J. M. , Leitch Ilia J. , Leitch Andrew  R. , Fay Michael F. ,   Royal Botanic Gardens Kew Genome Acquisition Lab,   Plant Genome Sizing collective,   Darwin Tree of Life Barcoding collective,   Wellcome Sanger Institute Tree of Life Management, Samples and Laboratory team,   Wellcome Sanger Institute Scientific Operations: Sequencing Operations,   Wellcome Sanger Institute Tree of Life Core Informatics team,   Tree of Life Core Informatics collective,   Darwin Tree of Life Consortium
Published: March 2024

We present a genome assembly from an individual Trifolium fragiferum (strawberry clover; Tracheophyta; Magnoliopsida; Fabales; Fabaceae). The genome sequence is 512.0 megabases in span. Most of the assembly is scaffolded into 8 chromosomal pseudomolecules. The mitochondrial and plastid genome assemblies have lengths of 298.57 kilobases and 139.15 kilobases in length, respectively.
The genome sequence of the Lesser Skullcap, Scutellaria minor Huds., 1762 (Lamiaceae)
Authors: Mian Sahr , Christenhusz Maarten J. M. , Leitch Ilia J ,   Royal Botanic Gardens Kew Genome Acquisition Lab,   Plant Genome Sizing collective,   Darwin Tree of Life Barcoding collective,   Wellcome Sanger Institute Tree of Life Management, Samples and Laboratory team,   Wellcome Sanger Institute Scientific Operations: Sequencing Operations,   Wellcome Sanger Institute Tree of Life Core Informatics team,   Tree of Life Core Informatics collective,   Darwin Tree of Life Consortium
Published: March 2024

We present a genome assembly from an individual Scutellaria minor (Tracheophyta; Magnoliopsida; Lamiales; Lamiaceae). The genome sequence is 341.8 megabases in span. Most of the assembly is scaffolded into 14 chromosomal pseudomolecules. The mitochondrial and plastid genome assemblies have lengths of 376.64 kilobases and 152.59 kilobases in length, respectively.
Is there anything beyond addiction psychotherapy in patients with cannabis use disorder? A rationale for prescribing medical marihuana as a harm reduction strategy
Authors: Więckiewicz Gniewko , Stokłosa Iga , Piegza Magdalena
Published: March 2024

Marihuana has been known to people for hundreds of years. Today, marihuana is either legal or decriminalized in many countries, particularly in Europe and the Americas, which may encourage use of the drug. Cannabis and its derivatives are used in medicine on the recommendation of doctors, including for the treatment of multiple sclerosis or drug-resistant epilepsy. There is a group of people who turn to marihuana on the street without regard to contraindications and side effects, and these are the recreational users who struggle with problematic use or addiction . Buying marihuana outside of the medical market means that the user may not realize the negative health effects of their use, and there are serious risks associated with the negative effects of the natural substances found in marihuana or the numerous and common marihuana contaminants, such as mercury and pesticides, among others. This review justifies the prescription of pharmaceutical-grade medical marihuana as part of health harm reduction for a group of cannabis use disorder patients who are unlikely to stop using marihuana from untested or illicit sources, while also discussing ethical and economic issues.
Smooth Nested Simulation: Bridging Cubic and Square Root Convergence Rates in High Dimensions
Authors: Wang Wenjia , Wang Yanyuan , Zhang Xiaowei
Published: March 2024

Nested simulation concerns estimating functionals of a conditional expectation via simulation. In this paper, we propose a new method based on kernel ridge regression to exploit the smoothness of the conditional expectation as a function of the multidimensional conditioning variable. Asymptotic analysis shows that the proposed method can effectively alleviate the curse of dimensionality on the convergence rate as the simulation budget increases, provided that the conditional expectation is sufficiently smooth. The smoothness bridges the gap between the cubic root convergence rate (that is, the optimal rate for the standard nested simulation) and the square root convergence rate (that is, the canonical rate for the standard Monte Carlo simulation). We demonstrate the performance of the proposed method via numerical examples from portfolio risk management and input uncertainty quantification.

This paper was accepted by Baris Ata, stochastic models and simulation.

Funding: The authors acknowledge financial support from the National Natural Science Foundation of China [Grant NSFC 12101149] and the Hong Kong Research Grants Council [Grants GRF 17201520 and GRF 17206821].

Supplemental Material: The e-companion and data files are available at https://doi.org/10.1287/mnsc.2022.00204 .
Optimal Impact Portfolios with General Dependence and Marginals
Authors: Lo Andrew W. , Wu Lan , Zhang Ruixun , Zhao Chaoyi
Published: March 2024

Using Induced Order Statistics to Construct Optimal Impact Portfolios with General Dependence and Marginals

We develop a mathematical framework for constructing optimal impact portfolios and quantifying their financial performance by characterizing the returns of impact-ranked assets using induced order statistics and copulas. Our results apply to any joint distribution of impact factors and residual returns, making them broadly applicable to a wide range of contexts. We develop significant extensions of the theory of induced order statistics, with which we are able to characterize the distribution of residual returns of individual assets ranked by the impact factor. Our framework provides a toolkit for practitioners to construct impact portfolios and quantify their performance based on real data. This allows impact investors to achieve higher risk-adjusted returns than those with impact portfolios constructed using simpler heuristics such as negative or positive screening.
Alkaline Hydrolysis of Poultry Carcasses and Health Risk Assessment of Exposure to Target Volatile Organic Compounds
Authors: Sun Zhihui , Akdeniz Neslihan , Banik Chumki , Koziel Jacek A.
Published: March 2024

Highlights

Hydroxide solutions (1 M, 2 M, 4 M) were used for chicken carcass hydrolysis.

pH of hydrolysates remained above 13.1 for the entire 10 weeks.

Headspace samples had characteristic fish odor due to trimethylamine.

Over 17% of the workers exposed to gases for 3 hours daily risk developing serious health risks.

Abstract. Animal carcass management is an essential part of a livestock production system. Alkaline hydrolysis is a relatively new disposal method used to digest and break down animal tissues. Despite the effectiveness of inactivating pathogens, alkaline hydrolysis has not been widely accepted as a disposal method because of its high capital and operating costs when done at high temperatures and pressure. The objectives of this research were (1) to test if alkaline solutions at ambient temperature and pressure can be used to hydrolyze poultry carcasses; (2) to quantify target VOCs emitted from carcasses, and (3) to neutralize and aerobically treat hydrolysates to prepare liquid fertilizer. 1 molar (M), 2 M, and 4 M potassium hydroxide solutions were used to hydrolyze chicken carcasses, and the headspace was sampled to quantify target VOCs. The pH of the hydrolysates stayed above 13.1 during the study, which was considered sufficient for eliminating pathogens of concern. Concentrations of target VOCs fluctuated over 10 weeks, and concentrations of trimethylamine (TMA), acetic acid, and propionic acid exceeded their recommended inhalation exposure limits. It was found that more than 17% of the workers exposed to the process headspace gases for 3 h a day would be at a high risk of developing serious chronic health problems. Although the results of this study indicated that chicken carcasses can be hydrolyzed under ambient conditions, they raised concerns about the health risks associated with inhalation exposure to the gases produced during the process. Future studies are needed to adjust daily exposure times depending on the ventilation rates of full-scale alkaline hydrolysis sites. Keywords: Alkaline hydrolysis, Cancer risk, Carcass, Livestock, Solid-phase microextraction.
Exploring Resistance Reduction of Subsoiling Through Sandfish (Scincus scincus) Inspired Sinusoidal Locomotion
Authors: Wei Zhiming , Gan Shuaihui , Zhang Zhihong , Sun Yitian , Li Qinglong , Sun Yongjia , Li Rui
Published: March 2024

Highlights

Biomimetic design, inspired by sandfish locomotion, decreased subsoiling resistance.

Penetration tests and simulations showed bioinspired tines outperforming traditional ones in resistance reduction.

DEM-MBD co-simulation effectively modeled the sandfish's movement, revealing the mechanisms of soil interactions.

Simulations confirmed that sinusoidal subsoiler movement significantly reduced soil resistance.

Abstract. This study addresses the issue of high resistance and low efficiency in subsoiling operations by employing a novel method inspired by the unique locomotion of the sandfish (scincus scincus), aimed at reducing forward resistance. The unparalleled adaptability of the sandfish in navigating granular media, such as desert sand, offers valuable insights for enhancing agricultural machinery. This research employs sandfish’s movement principles to propose innovative strategies for improving subsoiling efficiency. A sandfish inspired prototype, created through reverse engineering, served as the basis for the analysis. The models of both traditional (T-S) and bioinspired (B-S) subsoiler tines for comparative assessment were developed. The EDEM simulation model’s performance was calibrated using soil penetration tests and integrated with multibody dynamics (MBD) to analyze the sandfish’s variable locomotion in sandy soil. The impact of linear and sinusoidal locomotion at velocities of 0.8 m/s, 1.0 m/s, and 1.2 m/s on resistance and soil disturbance were investigated and contrasted. The congruence between measured and simulated resistance-depth curves for T-S and B-S models was desirable, with maximum resistance errors of 2.54% and 2.47%, respectively, confirming the simulation model’s accuracy in predicting mechanical interactions. A comparison of characteristic angles validated the close correlation between simulated and actual sandfish locomotion in soil. Stress analysis during soil locomotion of the sandfish head indicated a 25.1% reduction in resistance with sinusoidal motion compared to linear motion. At the specified velocities, sinusoidal locomotion of the subsoiler tine showed resistance reductions of 6.75%, 7.39%, and 9.40%, respectively, relative to linear locomotion. The mechanism of resistance reduction in sinusoidal locomotion was further verified through soil compression force analysis, supporting the adoption of sandfish-inspired sinusoidal behavior as an innovative approach to enhance efficiency in agricultural practices. Keywords: Bioinspired design, DEM-MBD simulation, Sandfish (Scincus scincus), Sinusoidal locomotion, Subsoiling.
Sorption Kinetics and Equilibrium Isotherms of Phosphine Gas into Wheat Kernels
Authors: Buenavista Rania Marie , Casada Mark E. , Phillips Thomas W. , Siliveru Kaliramesh
Published: March 2024

Highlights

The pseudo-first order kinetic model fits well with the experimental data of sorbed phosphine versus time.

Sorption isotherm curves were developed using Langmuir, Freundlich, and Redlich-Peterson models.

Phosphine adsorption capacity of wheat kernels increased with increase in applied concentration (400-2400 ppm).

Abstract. Phosphine (PH3) is the most used fumigant in the U.S. due to its low price, ease of use, and wide accessibility. With the growing concerns of phosphine-resistant insect pests, the sustainability of PH3 as an effective fumigant has been put at risk. Sorption equilibrium data is critical for improving the accuracy of modeling studies for phosphine-wheat fumigation systems and would clarify the PH3 uptake and sorption capacity of wheat. The objectives of this study were to determine the effect of initial concentration (from 400 to 2400 ppm) on the equilibrium concentration for PH3 in wheat kernels and on cumulative and daily PH3 sorption through time. Kinetic data showed the sorption process was time-dependent and occurred in two phases: an initial faster adsorption phase, followed by a phase with a slower sorption rate as the grain and PH3 reached equilibrium. Pseudo-first and pseudo-second order models were fit to PH3 concentrations versus time experimental data. The pseudo-first order model provided better equilibrium estimates and was used for the sorption isotherm analysis. Langmuir, Freundlich, and Redlich-Peterson sorption isotherm models were fit to the plot of equilibrium headspace gas concentration versus sorbed PH3 quantity. All three models had low standard errors of prediction (0.46-0.47). These PH3 sorption kinetics and values of total sorbed quantity at equilibrium are valuable for modeling the rate and maximum quantity of PH3 uptake in wheat. Keywords: Fumigation, Kinetics, Phosphine, Sorption Isotherm, Wheat.
Inverse design and optimization of an aperiodic multi-notch fiber Bragg grating using neural networks
Authors: Yu Qingshan , Norris Barnaby R. M. , Edvell Göran , Luo Liguo , Bland-Hawthorn Joss , Leon-Saval Sergio G.
Published: March 2024

Recent developments in the application of aperiodic fiber Bragg gratings (AFBGs) in astrophotonics, such as AFBG for astronomical near-infrared OH suppression and gas detection based on cross-correlation spectroscopy, have illuminated the problem that the optimization for AFBG with certain fabrication constraints has not been fully investigated and solved. Previous solutions will either sacrifice part of the spectral features or consume a significant amount of computation resources and time. Inspired by recently successful applications of artificial neural networks (ANNs) in photonics inverse design, we develop an AFBG optimization approach employing ANNs in conjunction with genetic algorithms (GAs) for the first time, to the best of our knowledge. The approach maintains the spectral notch depths and preserves the fourth-order super-Gaussian spectral features with improvements of interline loss by ∼100 times. We also implement, to our knowledge, the first inverse scattering neural network based on a tandem architecture for AFBG, using a first-order Gaussian notch profile. The neural network successfully converges but has a poor predictive capability for the phase part of the design. We discuss possible ways to overcome these limitations.
Surface reconstruction and thickness error calculation of optical components with a complex curved surface
Authors: Zhao Liangxiao , Wu Lunzhe , Fang Yuanyuan
Published: March 2024

The increasing demand for free-form irregular optical components in both military and civilian sectors has made the inspection of such unique shapes a central challenge that hinders their production and use. In particular, the shape and thickness errors of low- and medium-precision components thermally pressed from flat optical materials are greater than those of hard brittle optical components fabricated by subtractive manufacturing, and the resulting impact on human vision is more severe. Reasonable, convenient, efficient, and accurate 3D scanning and data processing for surface reconstruction that combines application scenarios and batch manufacturing needs are urgently needed. Based on the principles of optical ray tracing and triangulation processing, the sampling and calculation of optical path thickness proposed in this paper effectively establish a theoretical model for macroscopic distortion, providing a reasonable solution for distortion correction, batch manufacturing of free-form surface pressing formed components, and defect repair.
Indoor visible light communication denoising system combining iterative variational mode decomposition and multiple frequency shift keying modulation
Authors: Yang Chunyong , Hu Xin , Ni Wenjun , Shum Perry Ping
Published: March 2024

To reduce noise in indoor visible light communication (IVLC), the Pearson correlation coefficient difference (PCCD), a denoising system combining iterative variational mode decomposition (IVMD) and multiple frequency shift keying modulation (MFSK), is proposed. Compared with VMD, the method can directly determine the optimal number of VMD modes and solve the issue of VMD penalty factor selection to some extent. The simulation results show that, when the input SNRs vary from −15 to −8dB, the proposed method can improve the output SNRs of the 2FSK signal by an average of 15.5 dB and reduce the BER by 55.8%, improve the output SNR of the 4FSK signal by an average of 13 dB, and reduce the BER by 54.4%. The proposed method can also effectively suppress noise interference in real IVLC experiments at a distance of 1 m. In addition, the IVMD-MFSK denoising system can be applied to denoise all frequency-modulated signals with high applicability.
Semi-supervised learning model synergistically utilizing labeled and unlabeled data for failure detection in optical networks
Authors: Sun Zhiming , Zhang Chunyu , Zhang Min , Ye Bing , Wang Danshi
Published: March 2024

In optical networks, reliable failure detection is essential for maintaining quality of service. The methodology has evolved from traditional performance threshold-driven approaches to contemporary data-driven AI algorithms, predominantly employing supervised and unsupervised learning. However, with the advent of second-level telemetry, optical transport networks have amassed a wealth of unlabeled performance data, while labeled data remains limited due to the intensive effort required for annotation. In this scenario, to address the challenges of scarce labeled data in supervised learning and the accuracy issues in unsupervised methods, we propose an OpenFE-VIME semi-supervised model. This model synergizes the robustness of supervised approaches with the flexibility of unsupervised approaches. It not only leverages the abundant reservoir of unlabeled data but also addresses the challenges posed by the limited availability of labeled data, enabling reliable and efficient failure detection. Upon evaluation using performance data from OTN node devices in the operator’s optical backbone network, the OpenFE-VIME model demonstrates remarkable performance, achieving an F1-score of 0.947 and accuracy of 0.946, while significantly reducing false negative and false positive rates to 0.073 and 0.035, respectively. Moreover, our research explores the model’s capabilities in utilizing both labeled and unlabeled data and investigates the threshold for training convergence across various data ratios. Additionally, the model’s internal mechanisms and decision-making processes are interpreted using t-SNE visualization, offering enhanced insights into its operational efficacy.
Broadband silicon nitride integrated polarization rotators at 780 nm
Authors: Pruessner Marcel W. , Walsh Kyle J. , Tyndall Nathan F. , Fahrenkopf Nicholas M. , Antohe Alin O. , Stievater Todd H.
Published: March 2024

Polarization management, and in particular polarization rotation, is becoming increasingly important for photonic integrated circuits (PICs). While fiber-optic networks are generally polarization insensitive, the large aspect ratio of high-index-contrast PIC waveguides leads to a large polarization-dependent response of integrated components such as waveguides, optical cavities, couplers, etc. Although foundry-processed polarization rotators operating at telecom and datacom wavelengths (C- and O-band) have been demonstrated, to date, there have been few reports of devices operating at shorter wavelengths. This work demonstrates silicon nitride (SiN) polarization rotators operating from λ=700-1000 nm (the I/Z-band) that take advantage of optical coupling between two waveguiding layers in a standard foundry process. We demonstrate a broadband white-light polarization measurement setup that enables precise characterization of the polarization-dependent transmission of photonic waveguide devices. Measurements on foundry-processed devices confirm full TE-to-TM rotation exhibiting a maximum polarization extinction ratio (PER) approaching 20 dB (limited by our measurement setup), and an exceptionally large bandwidth of up to 160 nm with an insertion loss less than 0.2 dB. Beam propagation method (3D-BPM) simulations show good agreement with experimental data and enable the device parameters to be adjusted to accommodate different operating wavelengths and geometries with no changes to the existing foundry process. This work opens up opportunities for applications in quantum information and bio-sensing where operation at λ<1000nm is needed.
Near-infrared dual-gas sensor for simultaneous detection of CO and CH4 using a double spot-ring plane-concave multipass cell and a digital laser frequency stabilization system
Authors: Hu Zhen , Shi Yongpeng , Niu Mingsheng , Li Taohua , Li Hui , Liu Huiyuan , Li Xiangxian , Jiang Benshuai
Published: March 2024

A novel double spot-ring plane-concave multipass cell (DSPC-MPC) gas sensor was proposed for simultaneous detection of trace gases, which has lower cost and higher mirror utilization than the traditional multipass cell with 129 m, 107 m, 85 m, 63 m and 40 m effective optical path lengths adjustable. The performance of the DSPC-MPC gas sensor was evaluated by measuring CO and CH4 using two narrow linewidth distributed feedback lasers with center wavelengths of 1567 nm and 1653 nm, respectively. An adjustable digital PID laser frequency stabilization system based on LabVIEW platform was developed to continuously stabilize the laser frequency within ∼±30.3 MHz. The Allan deviation results showed that the minimum detection limits for CO and CH4 were 0.07 ppmv and 0.008 ppmv at integration times of 711 s and 245 s, respectively. The proposed concept of DSPC-MPC provides more ideas for the realization of gas detection under different absorption path lengths and the development of multi-component gas sensing systems.
Contrast-enhanced phase-resolved second harmonic generation microscopy
Authors: Wang Zhanshan , Hong Canyu , Sun Zeyuan , Wu Shuang , Liang Bokai , Duan Xidong , Liu Wei-Tao , Wu Shiwei
Published: March 2024

The characterization of inverted structures (crystallographic, ferroelectric, or magnetic domains) is crucial in the development and application of novel multi-state devices. However, determining these inverted structures needs a sensitive probe capable of revealing their phase correlation. Here a contrast-enhanced phase-resolved second harmonic generation (SHG) microscopy is presented, which utilizes a phase-tunable Soleil–Babinet compensator and the interference between the SHG fields from the inverted structures and a homogeneous reference. By this means, such inverted structures are correlated through the

π

-phase difference of SHG, and the phase difference is ultimately converted into the intensity contrast. As a demonstration, we have applied this microscopy in two scenarios to determine the inverted crystallographic domains in two-dimensional van der Waals material MoS2. Our method is particularly suitable for applying in vacuum and cryogenic environments while providing optical diffraction-limited resolution and arbitrarily adjustable contrast. Without loss of generality, this contrast-enhanced phase-resolved SHG microscopy can also be used to resolve other non-centrosymmetric inverted structures, e.g. ferroelectric, magnetic, or multiferroic phases.
Optimized adaptation algorithms for low-complexity adaptive equalizers
Authors: Zheng Shuo , Yang Min , Yan Guofeng , Zhu Yanjun , Zhang Hua , Yao Chaonan , Shao Yuchen , Wang Jian
Published: March 2024

In order to address the high-power consummation issue of conventional multi-input and multi-output (MIMO) adaptive equalizer (AEQ) for short-reach coherent transmissions, several state-of-the-art low-complexity AEQs have been proposed. In our work, optimized adaptation algorithms for low-complexity real-valued (RV) AEQs with different structures are analyzed. Moreover, an approach to avoid introducing additional computational complexity due to the optimized adaptation process is presented here. The advantages of proposed optimized adaptation algorithms are experimentally demonstrated in a 25 Gbaud dual-polarization 16-quadrature-amplitude-modulation (DP-16QAM) back-to-back (BtB) intradyne system with an overall bandwidth of 14 GHz. Experimental results show that a similar performance as the conventional AEQ could be achieved by using proposed adaptation algorithms and reducing the number of multiplications with up to ∼65%.
FPM-WSI: Fourier ptychographic whole slide imaging via feature-domain backdiffraction
Authors: Zhang Shuhe , Wang Aiye , Xu Jinghao , Feng Tianci , Zhou Jinhua , Pan An
Published: March 2024

Fourier ptychographic microscopy (FPM) theoretically provides a
solution to the trade-off between spatial resolution and field of view
(FOV), and has promising prospects in digital pathology. However,
block reconstruction and then stitching has become an unavoidable
procedure for reconstruction of large FOV due to vignetting artifacts.
This introduces digital stitching artifacts, as the existing
image-domain optimization algorithms are highly sensitive to
systematic errors. Such obstacles significantly impede the advancement
and practical implementation of FPM, explaining why, despite a decade
of development, FPM has not gained widespread recognition in the field
of biomedicine. We report a feature-domain FPM (FD-FPM) based on the
structure-aware forward model to realize stitching-free, full-FOV
reconstruction. The loss function is uniquely formulated in the
feature domain of images, which bypasses the troublesome vignetting
effect and algorithmic vulnerability via feature-domain
backdiffraction. Through massive simulations and experiments, we show
that FD-FPM effectively eliminates vignetting artifacts for full-FOV
reconstruction, and still achieves impressive reconstructions despite
the presence of various systematic errors. We also found it has great
potential in recovering the data with a lower spectrum overlapping
rate, and in realizing digital refocusing without a prior defocus
distance. With FD-FPM, we achieved full-color and high-throughput
imaging (4.7 mm diameter FOV, 336 nm resolution in the blue channel)
free of blocking-and-stitching procedures on a self-developed Fourier
ptychographic microscopy whole slide imaging platform. The reported
FD-FPM shows the value of FPM for various experimental circumstances,
and offers physical insights useful for the developments of models for
other computational imaging techniques. The reported platform
demonstrates high-quality, high-speed imaging and low cost, and could
find applications in many fields of biomedical research, as well as in
clinical applications.
Diffractive neural networks with improved expressive power for gray-scale image classification
Authors: Zheng Minjia , Liu Wenzhe , Shi Lei , Zi Jian
Published: March 2024

In order to harness diffractive neural networks (DNNs) for tasks that better align with real-world computer vision requirements, the incorporation of gray scale is essential. Currently, DNNs are not powerful enough to accomplish gray-scale image processing tasks due to limitations in their expressive power. In our work, we elucidate the relationship between the improvement in the expressive power of DNNs and the increase in the number of phase modulation layers, as well as the optimization of the Fresnel number, which can describe the diffraction process. To demonstrate this point, we numerically trained a double-layer DNN, addressing the prerequisites for intensity-based gray-scale image processing. Furthermore, we experimentally constructed this double-layer DNN based on digital micromirror devices and spatial light modulators, achieving eight-level intensity-based gray-scale image classification for the MNIST and Fashion-MNIST data sets. This optical system achieved the maximum accuracies of 95.10% and 80.61%, respectively.
Mobilisation towards formal employment in the healthcare system: A qualitative study of community health workers in South Africa
Authors: Malatji Hlologelo , Griffiths Frances , Goudge Jane
Published: March 2024

In low and middle-income countries, community health workers (CHWs) play a critical role in delivering primary healthcare (PHC) services. However, they often receive low stipends, function without resources and have little bargaining power with which to demand better working conditions. Using a qualitative case study methodology, we studied CHWs’ conditions of employment, their struggle for recognition as health workers, and their activities to establish labour representation in South Africa. Seven CHW teams located in semi-urban and rural areas of Gauteng and Mpumalanga Provinces were studied. We conducted 43 in-depth interviews, 10 focus groups and 6 observations to gather data from CHWs and their representatives, supervisors and PHC facility staff. The data was analysed using thematic analysis method. In the rural and semi-urban sites, the CHWs were poorly resourced and received meagre remuneration, their employment outsourced, without employment benefits and protection. As a result of these challenges, the CHWs in the semi-urban sites established a task team to represent them. They held meetings and caused disruptions in the health facilities. After numerous unsuccessful attempts to negotiate for improved conditions of employment, the CHWs joined a labour union in order to participate in the local Bargaining Council. Though they were not successful in getting the government to provide permanent employment, the union negotiated an increase in their stipend. After the study ended, during the height of COVID-19 in 2020, when the need for motivated and effective CHWs became more apparent to decision makers, the semi-urban-based teams received permanent employment with a better remuneration. The task team and their protests raised awareness of the plight of the CHWs, and joining a formal union enabled them to negotiate a modest salary increase. However, it was the emergency created by the world-wide COVID-19 pandemic that forced decision-makers to acknowledge their reliance on this community-based cadre.
Management practices in facilities providing HIV services to key populations in Kenya and Malawi: A descriptive analysis of management in community-based organizations
Authors: Salas-Ortiz Andrea , Opuni Marjorie , Rodríguez-Atristain Alejandra , Figeroa José Luis , Sánchez-Morales Jorge Eduardo , Bula Agatha Kapatuka , Nyambura Barbara , Bautista-Arredondo Sergio
Published: March 2024

HIV services for key populations (KP) at higher risk of HIV infection are often delivered by community-based organizations. To achieve HIV epidemic control, countries need to scale up HIV services for KP. Little is known about the management practices of community-based organizations delivering health services. We explored the management practices and facility characteristics of community-based health facilities providing HIV services to key populations as part of the LINKAGES program in Kenya and Malawi. We collected information on management practices from 45 facilities called drop-in centers (DICs) during US Government FY 2019, adapting the World Management Survey to the HIV community-based health service delivery context. We constructed management domain scores for each facility. We then analyzed the statistical correlations between management domains (performance monitoring, people management, financial management, and community engagement) and facility characteristics (e.g., number of staff, organization maturity, service scale) using ordinary least square models. The lowest mean management domain scores were found for people management in Kenya (38.3) and financial management in Malawi (25.7). The highest mean scores in both countries were for performance monitoring (80.9 in Kenya and 82.2 in Malawi). Within each management domain, there was significant variation across DICs, with the widest ranges in scores (0 to 100) observed for financial management and community involvement. The DIC characteristics we considered explained only a small proportion of the variation in management domain scores across DICs. Community-based health facilities providing HIV services to KP can achieve high levels of management in a context where they receive adequate levels of above-facility support and oversight—even if they deliver complex services, rely heavily on temporary workers and community volunteers, and face significant financial constraints. The variation in scores suggests that some facilities may require more above-facility support and oversight than others.
Multi-level factors associated with utilization of water, sanitation and hygiene services by mothers in Nepal
Authors: Dhital Shalik Ram , Chojenta Catherine , Loxton Deborah
Published: March 2024

Background

Providing improved water, sanitation, and hygiene (WASH) at a household level remains one of the major public health challenges in Nepal. Household mothers are likely to have limited access to combined WASH services, this is influenced by individual, and community factors. Individual components of an improved water source, sanitary toilet, fixed place for handwashing, and availability of soap and water were merged into one and called combined WASH. This paper aimed to identify the individual and community factors associated with combined WASH facilities and practices among mothers with children under five years in Nepal.

Methods

A cross-sectional study was conducted using data from the Nepal Demographic and Health Survey (NDHS), 2016. The weighted sample size of this study was 4887 mothers with children under five years. The independent variables within the mothers included age, education, occupation, and caste/ethnicity in addition to education of the husband, wealth index, exposure to the newspaper, radio and television, residence, ecological zones, provinces, distance and participation in health mother groups were analyzed with the outcome variable of combined WASH. A multi-level mixed effects logistic regression model was used to assess the relationship of explanatory variables with WASH.

Results

At an individual level, a rich wealth index was positively associated with combined WASH (AOR = 6.29; 95%CI: 4.63–8.54). Higher education levels and exposure to television had higher odds of having combined WASH. At the community level, the hill zone, urban residence, and Sudurpashim Provinces were positively associated with combined WASH while Madesh and Karnali Provinces and distance to water source greater than 31 minutes were associated with lower access to combined WASH.

Conclusion

Educated and rich household have positive association with combined WASH. It is recommended that both the health and other sectors may be instrumental in improving the combined WASH service for mothers at households.