bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase extraction method resistant to the nonlinearity for dynamic frequency scanning interferometry
Authors: Qian Ruitao , Guo Junkang , Wang Zian , Cai Dongliang , Tian Kai , Liu Zhigang
Published: September 2024

Dynamic frequency scanning interferometry (DFSI) offers the advantage of drift immunity in distance measurements, making it widely used in industrial applications. However, the nonlinear scanning characteristics of lasers can induce non-stationarity in interference signals, complicating the phase extraction process and decreasing the accuracy of dynamic distance measurement. This study investigates the phase extraction of non-stationary signals with multiple frequency components and proposes a second-order group delay error compensation algorithm. By utilizing complex Morlet wavelets and second-order time-varying signals to construct a group delay model, this algorithm enables precise extraction of non-stationary phases within specific frequency bands, thereby mitigating phase extraction errors in DFSI systems. Experimental results showcase the effectiveness of the algorithm in reducing the standard deviation of distance measurements from 20.26 μm to 11.47 μm by mitigating the nonlinearity. Furthermore, dynamic experiments validate the stability of the proposed algorithm in detecting vibrating and uniformly moving targets.
Real-time acousto-optic imaging using high-peak-power long-pulsed illumination
Authors: Figliolia François , Liu Qin , Janicot Sylvie , Georges Patrick , Lucas-Leclin Gaëlle , Huignard Jean-Pierre , Ramaz François , Tualle Jean-Michel , Bocoum Maïmouna
Published: September 2024

Acousto-optic imaging (AOI) of absorbing objects embedded in highly scattering media remains challenging, since the detectable signal suitable for image reconstruction is weak. To increase the detected signals to a level required by live biological applications, we designed a high-peak-power quasi-continuous laser source based on the coherent combination of two pulsed amplifiers, delivering 100-µs-long pulses with a 9 W peak power at a 100 Hz repetition rate while maintaining an average power below 100 mW; jointly used with a digital holographic detection that maximizes the amount of collected signal, we demonstrate for the first time to our knowledge the optical imaging of 2-cm-thick highly scattering media (µ
s
′ ∼ 10 cm−1) at near-video frame rate (0.2 Hz) using the Fourier transform-AOI.
Learned liquid crystal microlens array for joint optimized deep optical architecture in identifying metameric materials
Authors: Li Shiqi , Li Hui , Li Tian , Su Chenbo , Wu Yuntao
Published: September 2024

Multispectral imaging holds great promise for the detection of metameric materials. However, traditional multispectral imaging systems are characterized by their large volume, complex structure, and high computational requirements, limiting their practical application. We propose a jointly optimized deep optical architecture that combines the liquid crystal (LC) microlens array (MLA) characteristics and a multi-level perceptual spectral reconstruction network (MLP-SRN). The core of the architecture is to integrate the physical properties of the LC-MLA into the MLP-SRN using point spread function (PSF) optical convolution kernels, decoupling the light-field characteristic information collected by the LC-MLA at different voltages. Experimental results demonstrate that the incorporation of the physical properties of the LC-MLA not only reduces the system size and computational complexity but demonstrates excellent performance in identifying a metameric material.
Panoramic single-pixel imaging with megapixel resolution based on rotational subdivision
Authors: Cui Huan , Cao Jie , Zhang Haoyu , Zhou Chang , Yao Haifeng , Wang Yingbo , Hao Qun
Published: September 2024

Single-pixel imaging (SPI) using a single-pixel detector is an unconventional imaging method that has great application prospects in many fields to realize high-performance imaging. In particular, the recently proposed catadioptric panoramic ghost imaging (CPGI) extends the application potential of SPI to high-performance imaging at a wide field of view (FOV) with recent growing demands. However, the resolution of CPGI is limited by the hardware parameters of the digital micromirror device (DMD), which cannot meet ultrahigh-resolution panoramic imaging needs that require detailed information. Therefore, to overcome the resolution limitation of CPGI, we propose a panoramic SPI based on rotational subdivision (RSPSI). The key of RSPSI is to obtain the entire panoramic scene by the rotation-scanning of a rotating mirror tilted 45°, so that one single pattern that only covers one sub-FOV with a small FOV can complete an uninterrupted modulation on the entire panoramic FOV during a once-through pattern projection. Then, based on temporal resolution subdivision, the image sequence of sub-FOVs subdivided from the entire panoramic FOV can be reconstructed with pixel-level or even subpixel-level horizontal shifting adjacently. Experimental results using a proof-of-concept setup show that the panoramic image can be obtained with 10428 × 543 of 5,662,404 pixels, which is more than 9.6 times higher than the resolution limit of the CPGI using the same DMD. To the best of our knowledge, the proposed RSPSI is the first to achieve a megapixel resolution via SPI, which can provide potential applications in fields requiring imaging with ultrahigh-resolution and wide FOV.
Symmetry-breaking bifurcations of pure-quartic solitons in dual-core couplers
Authors: Li Pengfei , Dong Liangliang , Mihalache Dumitru , Malomed Boris A.
Published: September 2024

We investigate spontaneous symmetry- and antisymmetry-breaking bifurcations of solitons in a nonlinear dual-core waveguide with the pure-quartic dispersion and Kerr nonlinearity. Symmetric, antisymmetric, and asymmetric pure-quartic solitons (PQSs) are found, and their stability domains are identified. The bifurcations for both the symmetric and antisymmetric PQSs are of the supercritical type (alias phase transitions of the second kind). Direct simulations of the perturbed evolution of PQSs corroborate their stability boundaries predicted by the analysis of small perturbations.
Spontaneous parametric downconversion in a laser-poled lithium niobate nonlinear photonic crystal with nanoscale resolution
Authors: Yang Xinzhe , Yu Qian , Xu Xiaoyi , Chen Sixin , Xie Chenzhu , Zhu Shining , Xiao Min , Zhang Yong
Published: September 2024

Based on quasi-phase-matching (QPM) theory, nonlinear photonic crystals (NPCs) are capable of realizing efficient spontaneous parametric downconversion (SPDC) for the generation of photonic entangled states. However, the traditional electric field poling techniques employed in NPC fabrication often result in non-negligible processing errors of a few hundred nanometers, thus impeding the production of quantum photon pairs as intended. In this work, we investigate the SPDC photon pairs generated in a laser-poled lithium niobate (LN) NPC. By using the recently developed laser poling technique, the processing error of the NPC is substantially reduced to approximately 15 nm. Consequently, the coincidence counts of the generated photon pairs in the experiment reach 83.6% of the designed value. Our result paves the way for on-demand production of high-quality quantum sources, which has potential applications in quantum communications and quantum computations.
Phase-modulation-induced reconfigurable rotating photonic lattices in atomic vapors
Authors: Shen Yutong , Huang Yongping , Yuan Jiaqi , He Ruidong , Ning Shaohuan , He Zhiling , Du Lijun , Zhang Yanpeng , Zhang Zhaoyang
Published: September 2024

We propose a method to prepare optically induced rotating hexagonal and
honey-comb photonic lattices by employing the phase modulated
three-beam interference in atomic vapors with electromagnetically
induced transparency. The phase differences among the three beams are
dynamically elaborated to synthesize the circular motion (in
transverse dimensions) of waveguides in the photonic lattices.
Further, we verify this model experimentally in the case of low-speed
modulation. A weak Gaussian probe field is sent into the constructed
helical photonic lattices to image their structures under
electromagnetically induced transparency (EIT). The motion
trajectories of the sites on the discretized output patterns exhibit
repeated circles, advocating the formation of rotating lattices. By
introducing phase modulations to involved beams, we provide a
continent way for producing transverse motions in waveguide arrays
with reconfigurability in rotational direction, radius, and speed.
This work looks forward to promising applications in topological
photonics with great popularity.
Ultrabroadband mid-infrared emission and gas sensing of cobalt-doped chalcogenide glass ceramics
Authors: Liu Han , Gao Yuan , Jiang Yikang , Lu Xiaosong , Yang Zhijie , Wang Pengfei , Yang Zhiyong
Published: September 2024

Mid-infrared (MIR) gain materials are of great significance for the development of MIR tunable fiber lasers. Herein, for the first time, to the best of our knowledge, it is found that Ga2Se3 nanocrystals distributed in chalcogenide glass ceramics can provide new tetrahedral-coordinated sites that can be used to activate ultrabroadband MIR emissions of divalent transition metal ions, such as Co2+. Under the excitation of a 1550 nm diode laser, the transparent Ge–Ga–Se glass ceramic embedded with Co2+: Ga2Se3 nanocrystals shows an intense 2.5–5.5 µm ultrabroadband emission. The peak wavelength is located at ∼4.2 µm and the full width at half maximum exceeds 2 µm. Such emission properties, originating from the dual lattice sites of Ga3+ ions, are superior to those of transparent chalcogenide glass ceramics embedded with Co2+: ZnSe nanocrystals. Moreover, the gas detection system built based on the glass ceramic shows a sensitivity of 45.9 ppm for butane gas. Therefore, the chalcogenide glass ceramics embedded with active Co2+: Ga2Se3 nanocrystals have great potential in MIR tunable fiber lasers and gas sensing.
Optical activation function using a metamaterial waveguide for an all-optical neural network
Authors: Honda Yoshihiro , Shoji Yuya , Amemiya Tomohiro
Published: September 2024

In this study, we experimentally demonstrated that the nonlinear
optical coefficient of the original Si can be enhanced by
incorporating a metamaterial structure into an existing silicon
waveguide. The two-photon absorption coefficient enhanced by the
metamaterial structure was 424 cm/GW, which is 1.2 × 103
times higher than that of Si. Using this metamaterial waveguide-based
nonlinear optical activation function, we achieved a high inference
accuracy of 98.36% in the handwritten character recognition task,
comparable to that obtained with the ReLU function as the activation
function. Therefore, our approach can contribute to the realization of
more power-efficient and compact all-optical neural networks.
Ultra-broadband absorber designed with the aid of the particle swarm optimization algorithm
Authors: Wu Lejia , Kanwal Saima , Chen Xin , Wen Jing
Published: September 2024

This study proposes an ultrabroadband absorber composed of nanocolumns across the ultraviolet-near-infrared spectrum. Calculations indicate that the absorber maintains a consistent absorptivity exceeding 90% throughout the 350–1950nm band, with an average absorptivity of 96%. Leveraging the distinctive response of unit cells of varying sizes to different wavelengths, multiple unit cells are combined into a supercell and adjacent absorption peaks are consolidated to achieve broadband absorption. Particle swarm optimization is employed for a reverse design, which facilitates the determination of the optimal parameters for the unit cells. The results suggest the feasibility of designing absorbers featuring high efficiency, polarization insensitiveness, and wide angles. This study presents a promising method featuring high flexibility and low computational consumption for absorber design.
Dynamic of time-independent and time-dependent asymmetric Gross-Pitaevskii equation around exceptional point
Authors: Ramezanpour Shahab
Published: September 2024

Systems operating at exceptional points (EPs) are highly sensitive to small perturbations, making it challenging to work near an EP. Eigenvalue analysis of the Gross-Pitaevskii equation has shown that asymmetric nonlinearity can compensate for detuning effects. However, an experimentally feasible system based on asymmetric nonlinear coupled resonators has not yet been explored. Additionally, some intriguing features of such a system are hidden in time domain analysis, which is rarely investigated. In this study, we demonstrate this feature using a full-wave simulation of an asymmetric nonlinear coupled resonator based on the finite-element method in Comsol. The time-dependent analysis reveals that detuning can shift the system from PT-symmetric to broken PT-symmetric (or vice versa), and nonlinearity can reverse this dynamic. This study provides an experimental framework for examining exceptional points (EPs) in nonlinear detuned coupled resonators and opens up new avenues for fundamental research into the influence of nonlinearity and detuning on the system’s state during EP encirclement.
Subradiance and superradiant long-range excitation transport among quantum emitter ensembles in a waveguide
Authors: Fasser Martin , Ostermann Laurin , Ritsch Helmut , Hotter Christoph
Published: September 2024

In contrast to free space, in waveguides the dispersive and dissipative dipole–dipole interactions among quantum emitters exhibit a periodic behavior over remarkably long distances. We propose a novel setup, to our knowledge, exploiting this long-range periodicity in order to create highly excited subradiant states and facilitate fast controlled collective energy transport among far-apart ensembles coupled to a waveguide. For sufficiently large ensembles, collective superradiant emission into the fiber modes dominates over its free space counterpart. We show that, for a large number of emitters, a fast transverse coherent pulse can create almost perfect subradiant states with up to 50% excitation. On the other hand, for a coherent excitation of one sub-ensemble above an overall excitation fraction of 50% we find a nearly lossless and fast energy transfer to the ground state sub-ensemble. This transport can be enhanced or suppressed by controlling the positions of the ensembles relative to each other, while it can also be realized with a random position distribution. In the optimally enhanced case this fast transfer appears as superradiant emission with subsequent superabsorption, yet, without a superradiant decay after the absorption. The highly excited subradiant states, as well as the superradiant excitation transfer, appear as suitable building blocks in applications such as active atomic clocks, quantum batteries, quantum information protocols, and quantum metrology procedures such as fiber-based Ramsey schemes.
Linear and nonlinear coupling of light in twin-resonators with Kerr nonlinearity
Authors: Pal Arghadeep , Ghosh Alekhya , Zhang Shuangyou , Hill Lewis , Yan Haochen , Zhang Hao , Bi Toby , Alabbadi Abdullah , Del’Haye Pascal
Published: September 2024

Nonlinear effects in microresonators are efficient building blocks for all-optical computing and telecom systems. With the latest advances in microfabrication, coupled microresonators are used in a rapidly growing number of applications. In this work, we investigate the coupling between twin-resonators in the presence of Kerr nonlinearity. We use an experimental setup with controllable coupling between two high-Q resonators and discuss the effects caused by the simultaneous presence of linear and nonlinear coupling between the optical fields. Linear-coupling-induced mode splitting is observed at low input powers, with the controllable coupling leading to a tunable mode splitting. At high input powers, the hybridized resonances show spontaneous symmetry breaking (SSB) effects, in which the optical power is unevenly distributed between the resonators. Our experimental results are supported by a detailed theoretical model of nonlinear twin-resonators. With the recent interest in coupled resonator systems for neuromorphic computing, quantum systems, and optical frequency comb generation, our work provides important insights into the behavior of these systems at high circulating powers.
Reducing statistical noise in frequency ratio measurement between Ca+ and Sr optical clocks with a frequency-synthesized local oscillator from a Sr optical clock
Authors: Shi Haosen , Lu Bingkun , Zhang Huaqing , Hu Ruming , Qian Yuan , Huang Yao , Yang Tao , Yao Yuan , Yu Hongfu , Fang Zhanjun , Gao Kelin , Guan Hua , Lin Yige , Jiang Yanyi , Ma Longsheng
Published: September 2024

Optical frequency ratio measurement between optical atomic clocks is essential to precision measurement as well as the redefinition of the second. Currently, the statistical noise in frequency ratio measurement of most ion clocks is limited by the frequency instability of ion clocks. In this work, we reduce the statistical noise in the frequency ratio measurement between a transportable Ca+ optical clock and a Sr optical lattice clock down to 2.2×10−15/τ. The local oscillator of the Ca+ optical clock is frequency-synthesized from the Sr optical lattice clock, enabling a longer probe time for Ca+ clock transition. Compared to previous measurement using independent local oscillators, we achieve 10-fold reduction in comparison campaign duration.
Impact of phylogeny on the inference of functional sectors from protein sequence data
Authors: Dietler Nicola , Abbara Alia , Choudhury Subham , Bitbol Anne-Florence
Published: September 2024

Statistical analysis of multiple sequence alignments of homologous proteins has revealed groups of coevolving amino acids called sectors. These groups of amino-acid sites feature collective correlations in their amino-acid usage, and they are associated to functional properties. Modeling showed that nonlinear selection on an additive functional trait of a protein is generically expected to give rise to a functional sector. These modeling results motivated a principled method, called ICOD, which is designed to identify functional sectors, as well as mutational effects, from sequence data. However, a challenge for all methods aiming to identify sectors from multiple sequence alignments is that correlations in amino-acid usage can also arise from the mere fact that homologous sequences share common ancestry, i.e. from phylogeny. Here, we generate controlled synthetic data from a minimal model comprising both phylogeny and functional sectors. We use this data to dissect the impact of phylogeny on sector identification and on mutational effect inference by different methods. We find that ICOD is most robust to phylogeny, but that conservation is also quite robust. Next, we consider natural multiple sequence alignments of protein families for which deep mutational scan experimental data is available. We show that in this natural data, conservation and ICOD best identify sites with strong functional roles, in agreement with our results on synthetic data. Importantly, these two methods have different premises, since they respectively focus on conservation and on correlations. Thus, their joint use can reveal complementary information.
Distribution of calbindin-positive neurons across areas and layers of the marmoset cerebral cortex
Authors: Atapour Nafiseh , Rosa Marcello G. P. , Bai Shi , Bednarek Sylwia , Kulesza Agata , Saworska Gabriela , Teymornejad Sadaf , Worthy Katrina H. , Majka Piotr
Published: September 2024

The diversity of the mammalian cerebral cortex demands technical approaches to map the spatial distribution of neurons with different biochemical identities. This issue is magnified in the case of the primate cortex, characterized by a large number of areas with distinctive cytoarchitectures. To date, no full map of the distribution of cells expressing a specific protein has been reported for the cortex of any primate. Here we have charted the 3-dimensional distribution of neurons expressing the calcium-binding protein calbindin (CB+ neurons) across the entire marmoset cortex, using a combination of immunohistochemistry, automated cell identification, computerized reconstruction, and cytoarchitecture-aware registration. CB+ neurons formed a heterogeneous population, which together corresponded to 10–20% of the cortical neurons. They occurred in higher proportions in areas corresponding to low hierarchical levels of processing, such as sensory cortices. Although CB+ neurons were concentrated in the supragranular and granular layers, there were clear global trends in their laminar distribution. For example, their relative density in infragranular layers increased with hierarchical level along sensorimotor processing streams, and their density in layer 4 was lower in areas involved in sensorimotor integration, action planning and motor control. These results reveal new quantitative aspects of the cytoarchitectural organization of the primate cortex, and demonstrate an approach to mapping the full distribution of neurochemically distinct cells throughout the brain which is readily applicable to most other mammalian species.
The neural dynamics associated with computational complexity
Authors: Franco Juan Pablo , Bossaerts Peter , Murawski Carsten
Published: September 2024

Many everyday tasks require people to solve computationally complex problems. However, little is known about the effects of computational hardness on the neural processes associated with solving such problems. Here, we draw on computational complexity theory to address this issue. We performed an experiment in which participants solved several instances of the 0-1 knapsack problem, a combinatorial optimization problem, while undergoing ultra-high field (7T) functional magnetic resonance imaging (fMRI). Instances varied in computational hardness. We characterize a network of brain regions whose activation was correlated with computational complexity, including the anterior insula, dorsal anterior cingulate cortex and the intra-parietal sulcus/angular gyrus. Activation and connectivity changed dynamically as a function of complexity, in line with theoretical computational requirements. Overall, our results suggest that computational complexity theory provides a suitable framework to study the effects of computational hardness on the neural processes associated with solving complex cognitive tasks.
A retrospective assessment of forecasting the peak of the SARS-CoV-2 Omicron BA.1 wave in England
Authors: Keeling Matt J. , Dyson Louise
Published: September 2024

We discuss the invasion of the Omicron BA.1 variant into England as a paradigm for real-time model fitting and projection. Here we use a mixture of simple SIR-type models, analysis of the early data and a more complex age-structure model fit to the outbreak to understand the dynamics. In particular, we highlight that early data shows that the invading Omicron variant had a substantial growth advantage over the resident Delta variant. However, early data does not allow us to reliably infer other key epidemiological parameters—such as generation time and severity—which influence the expected peak hospital numbers. With more complete epidemic data from January 2022 are we able to capture the true scale of the epidemic in terms of both infections and hospital admissions, driven by different infection characteristics of Omicron compared to Delta and a substantial shift in estimated precautionary behaviour during December. This work highlights the challenges of real time forecasting, in a rapidly changing environment with limited information on the variant’s epidemiological characteristics.
Upstream open reading frames repress the translation from the iab-8 RNA
Authors: Frei Yohan , Immarigeon Clément , Revel Maxime , Karch François , Maeda Robert K.
Published: September 2024

Although originally classified as a non-coding RNA, the male-specific abdominal (MSA) RNA from the Drosophila melanogaster bithorax complex has recently been shown to code for a micropeptide that plays a vital role in determining how mated females use stored sperm after mating. Interestingly, the MSA transcript is a male-specific version of another transcript produced in both sexes within the posterior central nervous system from an alternative promoter, called the iab-8 lncRNA. However, while the MSA transcript produces a small peptide, it seems that the iab-8 transcript does not. Here, we show that the absence of iab-8 translation is due to a repressive mechanism requiring the two unique 5’ exons of the iab-8 lncRNA. Through cell culture and transgenic analysis, we show that this mechanism relies on the presence of upstream open reading frames present in these two exons that prevent the production of proteins from downstream open reading frames.
NEMF mutations in mice illustrate how Importin-β specific nuclear transport defects recapitulate neurodegenerative disease hallmarks
Authors: Plessis-Belair Jonathan , Ravano Kathryn , Han Ellen , Janniello Aubrey , Molina Catalina , Sher Roger B.
Published: September 2024

Pathological disruption of Nucleocytoplasmic Transport (NCT), such as the mis-localization of nuclear pore complex proteins (Nups), nuclear transport receptors, Ran-GTPase, and RanGAP1, are seen in both animal models and in familial and sporadic forms of amyotrophic lateral sclerosis (ALS), frontal temporal dementia and frontal temporal lobar degeneration (FTD\FTLD), and Alzheimer’s and Alzheimer’s Related Dementias (AD/ADRD). However, the question of whether these alterations represent a primary cause, or a downstream consequence of disease is unclear, and what upstream factors may account for these defects are unknown. Here, we report four key findings that shed light on the upstream causal role of Importin-β-specific nuclear transport defects in disease onset. First, taking advantage of two novel mouse models of NEMF neurodegeneration (NemfR86S and NemfR487G) that recapitulate many cellular and biochemical aspects of neurodegenerative diseases, we find an Importin-β-specific nuclear import block. Second, we observe cytoplasmic mis-localization and aggregation of multiple proteins implicated in the pathogenesis of ALS/FTD and AD/ADRD, including TDP43, Importin-β, RanGap1, and Ran. These findings are further supported by a pathological interaction between Importin-β and the mutant NEMFR86S protein in cytoplasmic accumulations. Third, we identify similar transcriptional dysregulation in key genes associated with neurodegenerative disease. Lastly, we show that even transient pharmaceutical inhibition of Importin-β in both mouse and human neuronal and non-neuronal cells induces key proteinopathies and transcriptional alterations seen in our mouse models and in neurodegeneration. Our convergent results between mouse and human neuronal and non-neuronal cellular biology provide mechanistic evidence that many of the mis-localized proteins and dysregulated transcriptional events seen in multiple neurodegenerative diseases may in fact arise primarily from a primary upstream defect in Importin- β nuclear import. These findings have critical implications for investigating how sporadic forms of neurodegeneration may arise from presently unidentified genetic and environmental perturbations in Importin-β function.
PNLDC1 catalysis and postnatal germline function are required for piRNA trimming, LINE1 silencing, and spermatogenesis in mice
Authors: Wei Chao , Yan Xiaoyuan , Mann Jeffrey M. , Geng Ruirong , Wang Qianyi , Xie Huirong , Demireva Elena Y. , Sun Liangliang , Ding Deqiang , Chen Chen
Published: September 2024

PIWI-interacting RNAs (piRNAs) play critical and conserved roles in transposon silencing and gene regulation in the animal germline. Three distinct piRNA populations are present during mouse spermatogenesis: fetal piRNAs in fetal/perinatal testes, pre-pachytene and pachytene piRNAs in postnatal testes. PNLDC1 is required for piRNA 3’ end maturation in multiple species. However, whether PNLDC1 is the bona fide piRNA trimmer and the physiological role of 3’ trimming of different piRNA populations in spermatogenesis in mammals remain unclear. Here, by inactivating Pnldc1 exonuclease activity in vitro and in mice, we reveal that the PNLDC1 trimmer activity is essential for spermatogenesis and male fertility. PNLDC1 catalytic activity is required for both fetal and postnatal piRNA 3’ end trimming. Despite this, postnatal piRNA trimming but not fetal piRNA trimming is critical for LINE1 transposon silencing. Furthermore, conditional inactivation of Pnldc1 in postnatal germ cells causes LINE1 transposon de-repression and spermatogenic arrest in mice, indicating that germline-specific postnatal piRNA trimming is essential for transposon silencing and germ cell development. Our findings highlight the germ cell-intrinsic role of PNLDC1 and piRNA trimming in mammals to safeguard the germline genome and promote fertility.
Enhancement of clinical signs in C3H/HeJ mice vaccinated with a highly immunogenic Leptospira methyl-accepting chemotaxis protein following challenge
Authors: Barbosa Liana Nunes , LIanes Alejandro , Madesh Swetha , Fayne Bryanna Nicole , Brangulis Kalvis , Linn-Peirano Sarah C. , Rajeev Sreekumari
Published: September 2024

Leptospirosis is the most widespread zoonosis and a life-threatening disease in humans and animals. Licensed killed whole-cell vaccines are available for animals; however, they do not offer heterologous protection, do not induce long-term protection, or prevent renal colonization. In this study, we characterized an immunogenic Leptospira methyl-accepting chemotaxis protein (MCP) identified through a reverse vaccinology approach, predicted its structure, and tested the protective efficacy of a recombinant MCP fragment in the C3H/HeJ mice model. The predicted structure of the full-length MCP revealed an architecture typical for topology class I MCPs. A single dose of MCP vaccine elicited a significant IgG antibody response in immunized mice compared to controls (P < 0.0001), especially the IgG1 and IgG2a subclasses. The vaccination with MCP, despite eliciting a robust immune response, did not protect mice from disease and renal colonization. However, survival curves significantly differed between groups, and the MCP-vaccinated group developed clinical signs faster than the control group. There were differences in gross and histopathological changes between the MCP-vaccinated and control groups. The factors leading to enhanced disease process in vaccinated animals need further investigation. We speculate that anti-MCP antibodies may block the MCP signaling cascade and may limit chemotaxis, preventing Leptospira from reaching its destination, but facilitating its maintenance and replication in the blood stream. Such a phenomenon may exist in endemic areas where humans are highly exposed to Leptospira antigens, and the presence of antibodies might lead to disease enhancement. The role of this protein in Leptospira pathogenesis should be further evaluated to comprehend the lack of protection and potential exacerbation of the disease process. The absence of immune correlates of protection from Leptospira infection is still a major limitation of this field and efforts to gather this knowledge are needed.
Breaking the silence of female genital schistosomiasis in Ghana’s health system: A case of health workers within the FAST project
Authors: Gyapong Margaret , Dalaba Maxwell Ayindenaba , Immurana Mustapha , Manyeh Alfred Kwesi , Arogundade Kazeem , Jacobson Julie , Krentel Alison
Published: September 2024

Background

Female Genital Schistosomiasis (FGS) remains a critical and yet neglected topics in Neglected Tropical Diseases (NTDs), significantly affecting the health of women and girls worldwide. Health workers’ knowledge of FGS is vital to the prevention and management of the disease. This study adopted an implementation research approach to identify and address the existing knowledge gap regarding FGS among healthcare workers in Ghana.

Methods

This study was a 3-year (2020–2022) implementation research applying a pragmatic uncontrolled quasi-experimental study design. The study involved a baseline assessment, FGS training intervention for health workers and student nurses, distribution of FGS educational materials, and an endline assessment. A mixed-method approach was applied to data collection involving health workers from two schistosomiasis endemic districts and across the country. NVIVO 12 and STATA 14 were used for qualitative and quantitative data analysis, respectively.

Results

Prior to the intervention, the level of awareness about FGS among health workers was less than 8%, and most participants only understood FGS as merely urogenital schistosomiasis in females. In response to this gap, an FGS education intervention in the form of training of health workers, student nurses alongside the distribution of FGS educational materials were carried out. The intervention enhanced health workers’ awareness of FGS to more than 61%, encompassing an enhanced understanding of the disease’s signs and symptoms to more than 60%, as well as its management strategies. However, access to praziquantel, the primary treatment, remained a significant challenge.

Conclusions

The FGS intervention effectively raised healthcare workers’ awareness and knowledge. Expanding training and improving praziquantel access are essential for optimal FGS management. A multi-faceted approach involving individuals, communities, and the healthcare system is necessary for comprehensive FGS prevention and control.
Ethosuximide-loaded bismuth ferrite nanoparticles as a potential drug delivery system for the treatment of epilepsy disease
Authors: Guldorum Yeliz , Ayran Musa , Bulut Burcak , Ilgar Sule , Ulag Songul , Kanli Zehra , Aydin Banu , Gulhan Rezzan , Bedir Tuba , Gunduz Oguzhan , Narayan Roger J.
Published: September 2024

Encapsulating antiepileptic drugs (AEDs), including ethosuximide (Etho), into nanoparticles shows promise in treating epilepsy. Nanomedicine may be the most significant contributor to addressing this issue. It presents several advantages compared to traditional drug delivery methods and is currently a prominent area of focus in cancer research. Incorporating Etho into bismuth ferrite (BFO) nanoparticles within diverse controlled drug delivery systems is explored to enhance drug efficacy. This approach is primarily desired to aid in targeted drug delivery to the brain’s deepest regions while limiting transplacental permeability, reducing fetal exposure, and mitigating associated adverse effects. In this investigation, we explored Etho, an antiepileptic drug commonly employed for treating absence seizures, as the active ingredient in BFO nanoparticles at varying concentrations (10 and 15 mg). Characterization of the drug-containing BFO nanoparticles involved scanning electron microscopy (SEM) and elemental analysis. The thermal properties of the drug-containing BFO nanoparticles were evaluated via differential scanning calorimetry (DSC) analysis. Cytotoxicity evaluations using the MTT assay were conducted on all nanoparticles, and human neuroblastoma cell line cultures (SH-SY5Y) were treated with each particle over multiple time intervals. Cell viability remained at 135% after 7 days when exposed to 15 mg of Etho in BFO nanoparticles. Additionally, in vitro drug release kinetics for Etho revealed sustained release lasting up to 5 hours with a drug concentration of 15 mg.
Competencies needed for public health workforce in the programs of Iran’s health transformation plan: A descriptive study based on programs, operations, and competencies chain
Authors: Mohammadi Parvin , Fadaei Dehcheshmeh Nayeb
Published: September 2024

Background and purpose

The public health workforce faces a wide range of challenges related to people’s health. Thus, they need a combination of different professional skills and competencies to perform essential public health operations and provide services to people. The present study was conducted to determine the competencies needed for the public health workforce to implement health transformation plan programs at Ahvaz University of Medical Sciences in the capital of Khuzestan province in Iran.

Methods

This research was a descriptive cross-sectional study that was conducted in 2020 among 51 managers and experts of the health deputy and faculty members of the public health school. STROBE guideline was used for the present study. The research tools were two researcher-made questionnaires based on the chain of Programs, Operations, and Competencies (POC). Additionally, the validity and reliability of the questionnaires were checked. Cronbach’s alpha coefficient was equal to 0.87 for the first questionnaire (programs-operations) and 0.85 for the second questionnaire (operations-competencies).

Results

The operations of surveillance of population health and well-being, monitoring and responding to health hazards and emergencies, and disease prevention, including early detection of illness, obtained the highest mean total score (3.9 (95% CI: 3.6 to 4.2)). Respect for and adherence to ethical principles and confidentiality in any professional activity obtained the highest mean total score (4.0 (95% CI: 3.7 to 4.3)) among the needed competencies.

Conclusion

To properly implement public health programs, managers must plan and take necessary measures to improve such operations as surveillance of population health and well-being, monitoring and responding to health hazards and emergencies, disease prevention (including early detection of illness), and promotion of the workforce competencies in the field of respect for and adherence to ethical principles and confidentiality in any professional activity.
The role of executives’ social capital in improving merger and acquisition performance during corporate transformation and upgrading: Evidence from Chinese media enterprises
Authors: Yang Wancheng , Zeng Qi
Published: September 2024

During the transformation and upgrading of enterprises, executives’ social capital provides useful access to resources through merger and acquisition (M&A) strategies. This study examines 145 M&A events of Chinese listed media enterprises undergoing transformation and upgrading as research samples. It empirically analyzed the impact of executives’ social capital on short-term and long-term M&A performance from three aspects: corporate social capital (CSC), political social capital (PSC), and financial social capital (FSC). It also confirmed the moderating effect of corporate ownership structure, exploring the mechanism of executives’ social capital during the period of transformation and upgrading. Based on the empirical results, we found that: (1) CSC significantly enhances short-term M&A performance but has no significant effect on long-term performance; (2) PSC positively influences both short-term and long-term M&A performance. State-owned media enterprises may gain relatively fewer benefits from PSC in the short term after M&A, but they can accrue more significant benefits in the long term post-M&A; (3) FSC does not affect short-term M&A performance but exerts a negative impact on long-term performance. The negative effect is even more pronounced in state-owned enterprises. This study complements existing research on executives’ social capital during the transformation and upgrading of enterprises. It provides a reference for media enterprises in China and other emerging economies to utilize executives’ social capital.
Healthcare workers’ perspectives on diabetic foot complications among type 2 diabetes mellitus patients in Fiji
Authors: Saverio Suliana , Mohammadnezhad Masoud , Raikanikoda Filimone
Published: September 2024

Introduction

Diabetic Foot Complications (DFCs) are a growing cause of morbidity and mortality with less than one third of physicians able to discern the signs of diabetes related peripheral neuropathy. DFCs and resultant amputations account for a considerable proportion of surgeries in Fiji, with very limited literature available to verify the factors that influence these alarming figures. This study aimed to explore Health Care Workers’ (HCWs) perspectives on diabetic foot complications and challenges of foot care management in Fiji.

Method

An exploratory descriptive qualitative design was used among HCWs at the Sigatoka Sub Divisional Hospital (SDH), Fiji in 2021. HCWs at the SDH were required to have a minimum work experience of at least six months in public health. All participants who met the inclusion criteria were selected through purposive sampling. Data was collected using a focus group discussion guide composed of semi-structured open-ended questions to guide the Focus Group Discussions (FGDs). Focus discussions were audio recorded and transcribed with thematic analysis applied to derive the themes and sub-themes outlined in the study.

Results

Twenty HCWs participated in four FGDs with four major themes identified. The first theme was HCWs’ perceptions and practice of foot care which revealed that all participants had adequate diabetic foot care knowledge. The second theme was factors affecting foot care which was mainly focused on identified barriers such as inadequate patient foot care knowledge, the lack of resources such as manpower, and health system challenges like the COVID-19 pandemic. The third theme is creating awareness among patients and HCWs to improve foot care practices. The fourth theme is strengthening foot care practices at the different levels of health care that is aimed at optimizing diabetic foot outcomes.

Conclusion

Various foot care barriers namely patient factors and the lack of resources is a concern depicted in this study. There is a need to address health system barriers and enforce diabetic foot education, screening and care for patients and the community.
In vitro co-culture system for investigating Armillaria root rot in Prunus spp. using a fiber-supported liquid approach
Authors: Calle Alejandro , Adelberg Jeffrey , Schnabel Guido , Naylor-Adelberg Jacqueline , Gelain Jhulia , Karakoc Yeter , Weaver Jared , Saski Christopher , Gasic Ksenija
Published: September 2024

In vitro co-culture techniques that allow the growth of plants and pathogens under controlled environmental conditions are being used to re-create host plant infection. These approaches reduce infection times, promote reproducibility, and enable a rapid evaluation of plant-pathogen interactions. As a result, these systems have become essential in breeding programs aimed at developing plant resistance to diseases. In this study, we developed and validated an in vitro co-culture system to investigate the Armillaria root rot (ARR) affecting Prunus spp. This disease, caused by fungi Armillaria spp. and Desarmillaria caespitosa, poses a severe threat to the stone and nut fruit industry due to the susceptibility of most commercial rootstocks to infection and the lack of effective management options for its control. The system consists of a fiber-supported liquid approach in sterile plastic vessels that allows a fast and reproducible fungal infection under controlled environmental conditions. The floor of the vessels was covered with a polyester-fiber matte and a germination paper that served as an interface between the mycelia and the plant roots. The vessels were subjected to inoculation with Armillaria mellea and D. caespitosa, and three Prunus genotypes (‘Guardian®’, ‘MP-29’, and Prunus cerasifera ‘14–4’) were co-cultured with both fungi. Disease progression and plant and fungal biomass were monitored during co-culture. The presented in vitro co-culture approach facilitates the concurrent growth of Armillaria/Desarmillaria spp. and Prunus spp., excluding most of the limitations associated with greenhouses and field experiments. This system provides consistent and reproducible conditions for investigating a prominent plant disease affecting Prunus spp.
Arabic within culture forensic interviews: Arabic native speaking lay-observer truth and lie accuracy, confidence, and verbal cue selection
Authors: Dando Coral J. , Sandham Alexandra L. , Sibbons Charlotte , Taylor Paul J.
Published: September 2024

Cross cultural differences in behavioral and verbal norms and expectations can undermine credibility, often triggering a lie bias which can result in false convictions. However, current understanding is heavily North American and Western European centric, hence how individuals from non-western cultures infer veracity is not well understood. We report novel research investigating native Arabic speakers’ truth and lie judgments having observed a matched native language forensic interview with a mock person of interest. 217 observers viewed a truthful or a deceptive interview and were directed to attend to detailedness as a veracity cue or given no direction. Overall, a truth bias (66% accuracy) emerged, but observers were more accurate (79%) in the truth condition with the truthful interviewee rated as more plausible and more believable than the deceptive interviewee. However, observer accuracy dropped to just 23% when instructed to use the detailedness cue when judging veracity. Verbal veracity cues attended too were constant across veracity conditions with ‘corrections’ emerging as an important veracity cue. Some results deviate from the findings of research with English speaking western participants in cross- and matched-culture forensic interview contexts, but others are constant. Nonetheless, this research raises questions for research to practice in forensic contexts centred on the robustness of western centric psychological understanding for non-western within culture interviews centred on interview protocols for amplifying veracity cues and the instruction to note detailedness of verbal accounts which significantly hindered Arabic speaker’s performance. Findings again highlight the challenges of pancultural assumptions for real-world practices.
Synergetic inhibitory effect of isopropyl methylphenol-based agents on biofilm formation by Streptococcus mutans
Authors: Korenaga Arisu , Miyaoka Toshiki , Asami Harumi , Yamagami Yasushi , Yoshii Miki , Tanaka Shigemitsu , Nagao Toshihiro
Published: September 2024

Dental caries and periodontitis are the most common oral diseases in humans and the main causes of tooth loss. Streptococcus mutans is primarily responsible for dental caries and dental plaque, which are triggered by biofilm formation on the tooth surface. In this study, biofilm inhibition by 4-isopropyl-3-methylphenol (IPMP)-based agents, consisting of IPMP and polyoxyethylene-hydrogenated castor oil (POEHCO), was investigated in vitro. Notably, the use of POEHCO in addition to IPMP inhibited S. mutans biofilms more drastically than IPMP alone. Moreover, the effects of IPMP on the expression of biofilm-related genes (gtfB, gtfC, and gtfD) were examined using quantitative real-time PCR. IPMP at sub-minimum inhibitory concentrations significantly downregulated the expression of these genes. These results suggested that the inhibitory effects on biofilm formation were synergistically enhanced by the surfactant and antibiofilm activities of IPMP. Therefore, IPMP-based agents as dentifrices may be useful to prevent oral diseases originating from biofilms.