bluuebunny/crossref_metadata_2025 huggingface dataset:
Optical single-channel cryptosystem based on the non-negative matrix factorization and face biometric in cyan–magenta–yellow–black color space
Authors: Zhang Liao , Tang Chen , Shen Yuxin , He Hongxuan , Tang Hengyi , Lei Zhenkun
Published: October 2023

In this paper, an optical color single-channel asymmetric cryptosystem based on the non-negative matrix factorization (NMF) and a face biometric in cyan–magenta–yellow–black (CMYK) space is proposed. To the best of our knowledge, this is the first time that NMF has been introduced into optical color image encryption. In the proposed cryptosystem, the color image in CMYK space is first decomposed into four color channels: C, M, Y, and K. By performing NMF operations on the four color channels, the four basic and sparse matrices can be obtained, respectively, which achieves asymmetry and saves computational resources. The four basis matrices can be used as private keys, and the four coefficient matrices are synthesized by the inverse discrete wavelet transform for subsequent encryption. Finally, the synthesized image is encoded with double random phase encoding based on phase truncation (PT). Compared with the existing PT-based cryptosystems, our cryptosystem can improve security against a special attack. In addition, the chaotic random phase mask is generated by a face biometric, which is noncontact and unique. Numerical simulation results are shown to verify the feasibility and robustness of our cryptosystem. Further, the proposed cryptosystem can be extended to encrypt multiple images conveniently.
Channeling of weak intramode beams in the field of a strong spatial soliton in a thin left-handed film on a right-handed substrate with Kerr effect
Authors: Buller A. , Litvinov R. , Melikhova N.
Published: October 2023

The trapping of weak guided modes by a strip waveguide induced by a strong spatial soliton in a planar waveguide based on a thin left-handed film with a right-handed linear cover and a substrate with the Kerr effect at a frequency near the zero group velocity of the TE mode is considered. It is shown that a bright (dark) soliton can induce a strip waveguide not only for a positive (negative) nonlinear optical coefficient of the substrate, but also for a negative (positive) one, which is due to the existence in the original planar waveguide of guided modes with both positive and negative group velocities.
Stacked ring resonators for optical vortices
Authors: Alexeyev C. N. , Barshak E. V. , Lapin B. P. , Yavorsky M. A.
Published: October 2023

In this paper, we study transmission of higher-order modes, optical vortices (OVs) included, through a bus fiber coupled to a vertical stack of ring resonators—stack multi-ring resonator (SMR). We show that transmission curves for OVs feature a characteristic gap-like structure, whose presence we explain as a manifestation of the band structure of an infinite stack of coupled ring resonators. We show a principal possibility to use SMRs as elements of delay lines for fiber optics communications on orbital angular momentum (OAM) states. We emphasize the advantages of such systems as delay lines for communications that use as signal carriers odd and even Laguerre–Gaussian (LG) modes. We also show that SMRs are able to exert super-efficient parametric control over the OAM of the transmitted optical field, as well as to generate OAM beams from odd and even LG modes.
Spatial pilot-aided fast-adapted framework for stable image transmission over long multi-mode fiber
Authors: Zhang Shuqi , Wang Qinghua , Zhou Wei , Yan An , Zhang Junwen , Shi Jianyang , Chi Nan , Li Ziwei
Published: October 2023

Multi-mode fiber (MMF) has emerged as a promising platform for spatial information transmission attributed to its high capacity. However, the scattering characteristic and time-varying nature of MMF pose challenges for long-term stable transmission. In this study, we propose a spatial pilot-aided learning framework for MMF image transmission, which effectively addresses these challenges and maintains accurate performance in practical applications. By inserting a few reference image frames into the transmitting image sequence and leveraging a fast-adapt network training scheme, our framework adaptively accommodates to the physical channel variations and enables online model update for continuous transmission. Experimented on 100 m length unstable MMFs, we demonstrate transmission accuracy exceeding 92% over hours, with pilot frame overhead around 2%. Our fast-adapt learning scheme requires training of less than 2% of network parameters and reduces the computation time by 70% compared to conventional tuning approaches. Additionally, we propose two pilot-insertion strategies and elaborately compare their applicability to a wide range of scenarios including continuous transmission, burst transmission and transmission after fiber re-plugging. The proposed spatial pilot-aided fast-adapt framework opens up the possibility for MMF spatial transmission in practical complicated applications.
Quasi-phase matching using frozen waves without periodic poling
Authors: Alghannam Fahad S.
Published: October 2023

In this article, we show that quasi-phase matching can be accomplished by manipulating one of the pump beams without any periodic poling. We analyze a simple case wherein one of the interacting beams has a periodic pattern, and the others are assumed to be planewaves. We present comparisons of the efficiency of some nonlinear processes with quasi-phase matching achieved through our method and the conventional method. We demonstrate that some patterns of the pump beam can be more efficient than conventional periodic poling.
Terahertz determination of imidacloprid in soil based on a metasurface sensor
Authors: Zhang Xuan , Wu Xia , Xiao Binggang , Qin Jianyuan
Published: October 2023

Pesticides in soil are continuously one of the most studied analytes due to their environmental and human health effects. Thus the detection of pesticides in soil is an important means to control and assess soil quality. Here, we theoretically and experimentally present a novel method for the determination of imidacloprid in soil by using a metasurface sensor operating at terahertz frequencies. The metasurface shows a resonance peak at 880 GHz and the electric field at the peak is strongly localized and concentrated in the gap of split I-shaped resonator. The detection of complex refractive index shows that the position and the transmittance of resonance peak are depend on the change in the complex refractive index. The measurement of imidacloprid concentration in soil demonstrates that both the frequency shift and the transmittance change at peak increase almost linearly with the increasing of imidacloprid concentration ranging from 0.25% to 2%. In this case, the frequency shift reaches 97 GHz and the transmittance change at peak is as high as 30.9%. Our work enables the determination of imidacloprid in soil at terahertz frequencies with good reliability and high sensitivity, showing the potential application of terahertz spectroscopy in environmental monitoring.
Non-imaging metasurface design for collimated beam shaping
Authors: Nielsen Kirstine E. S. , Carlsen Mads A. , Zambrana-Puyalto Xavier , Raza Søren
Published: October 2023

Non-imaging optical lenses can shape the light intensity from incoherent sources to a desired target intensity profile, which is important for applications in lighting, solar light concentration, and optical beam shaping. Their surface curvatures are designed to ensure optimal transfer of energy from the light source to the target. The performance of such lenses is directly linked to their asymmetric freeform surface curvature, which is challenging to manufacture. Metasurfaces can mimic any surface curvature without additional fabrication difficulty by imparting a spatially-dependent phase delay using optical antennas. As a result, metasurfaces are uniquely suited to realize non-imaging optics, but non-imaging design principles have not yet been established for metasurfaces. Here, we take an important step in connecting non-imaging optics and metasurface optics, by presenting a phase-design method for beam shaping based on the concept of optimal transport. We establish a theoretical framework that enables a collimated beam to be redistributed by a metasurface to a desired output intensity profile. The optimal transport formulation leads to metasurface phase profiles that transmit all energy from the incident beam to the output beam, resulting in an efficient beam shaping process. Through a variety of examples, we show that our approach accommodates a diverse range of different input and output intensity profiles. Last but not least, a full field simulation of a metasurface has been done to verify our phase-design framework.
Threshold plasticity of SOI-GST microring resonators
Authors: Fu Ziling , Wang Zhi , Bienstman Peter , Jiang Rui , Jia Tao , Wang Huiying , Shang Chao , Wu Chongqing
Published: October 2023

Spiking Neural Networks, also known as third generation Artificial Neural Networks, have widely attracted more attention because of their advantages of behaving more biologically interpretable and being more suitable for hardware implementation. Apart from using traditional synaptic plasticity, neural networks can also be based on threshold plasticity, achieving similar functionality. This can be implemented using e.g. the Bienenstock, Cooper and Munro rule. This is a classical unsupervised learning mechanism in which the threshold is closely related to the output of the post-synaptic neuron. We show in simulations that the threshold characteristics of the nonlinear effects of a microring resonator integrated with Ge2Sb2Te5 demonstrate some complex dependencies on the intracavity refractive index, attenuation, and wavelength detuning of the incident optical pulse, and exhibit class II excitability. We also show that we are able to modify the threshold power of the microring resonator by the changes of the refractive index and loss of Ge2Sb2Te5, due to transitions between the crystalline and amorphous states. Simulations show that the presented device exhibits both excitatory and inhibitory learning behavior, either lowering or raising the threshold.
Complex-valued matrix–vector multiplication system for a large-scale optical FFT
Authors: Cao Ziyu , Zhang Wenkai , Zhou Hailong , Dong Jianji , Zhang Xinliang
Published: October 2023

Recent advancements in optical convolutional neural networks (CNNs) and radar signal processing systems have brought an increasing need for the adoption of optical fast Fourier transform (OFFT). Presently, the fast Fourier transform (FFT) is executed using electronic means within prevailing architectures. However, this electronic approach faces limitations in terms of both speed and power consumption. Concurrently, existing OFFT systems struggle to balance the demands of large-scale processing and high precision simultaneously. In response, we introduce a novel, to the best of our knowledge, solution: a complex-valued matrix–vector system harnessed through wavelength selective switches (WSSs) for the realization of a 24-input optical FFT, achieving a high-accuracy level of 5.4 bits. This study capitalizes on the abundant wavelength resources available to present a feasible solution for an optical FFT system with a large N.
On-orbit space optical communication demonstration with a 22 s acquisition time
Authors: Wang Xuan , Han Junfeng , Cui Kai , Wang Chen , Xie Meilin , Meng Xiangsheng , Chang Zhiyuan
Published: October 2023

The inherent small divergence angle of space optical communication poses significant challenges to establishing communication links. Therefore, laser link acquisition becomes a crucial technology in optical communication, with a primary focus on reducing the acquisition time effectively. Conventional optical communication acquisition techniques fail to address the error effects caused by satellite insertion into the Earth orbit, thus unable to meet the rapid establishment demands of laser links in satellite optical communication networks. In this regard, we propose a novel, to the best of our knowledge, on-orbit calibration method for laser communication terminals to our knowledge. Leveraging stellar observations, this method achieves efficient on-orbit calibration with only a single observation. Theoretical analysis and on-orbit experimental results demonstrate that this approach effectively enhances an open-loop pointing accuracy, offering promising prospects for achieving a rapid establishment of optical communication links in ultra-long-distance optical communication missions.
Soliton and bound-state soliton mode-locked fiber laser based on polarization-dependent grating
Authors: Jiang Chen , Zhou Rui , Fang Zhen , Wan Ying , Sun Bing , Mou Chengbo , Liu Yunqi , Zhang Zuxing
Published: October 2023

We demonstrate the generation of solitons and bound-state solitons in a passively mode-locked fiber laser based on the nonlinear polarization rotation effect by polarization-dependent helical grating. The CO2-laser-inscribed grating has a high polarization-dependent loss of 24.4 dB at 1558.4 nm, which has facilitated the achievement of stable mode locking. The soliton laser could generate 548.9 fs pulses at 1560.59 nm with a spectrum bandwidth of 5.45 nm and a signal-to-noise ratio of 75.2 dB. Through adjustment of the polarization controller and pump power, a bound-state soliton mode-locked pulse with a spectral modulation period of 3.11 nm was achieved and the temporal interval between the two solitons was 2.19 ps. Furthermore, its repetition rate can be easily manipulated by varying the pump power. The results indicated that the polarization-dependent helical grating is an excellent polarizer that could be applied in an ultrafast fiber laser.
Batch normalization followed by merging is powerful for phenotype prediction integrating multiple heterogeneous studies
Authors: Gao Yilin , Sun Fengzhu
Published: October 2023

Heterogeneity in different genomic studies compromises the performance of machine learning models in cross-study phenotype predictions. Overcoming heterogeneity when incorporating different studies in terms of phenotype prediction is a challenging and critical step for developing machine learning algorithms with reproducible prediction performance on independent datasets. We investigated the best approaches to integrate different studies of the same type of omics data under a variety of different heterogeneities. We developed a comprehensive workflow to simulate a variety of different types of heterogeneity and evaluate the performances of different integration methods together with batch normalization by using ComBat. We also demonstrated the results through realistic applications on six colorectal cancer (CRC) metagenomic studies and six tuberculosis (TB) gene expression studies, respectively. We showed that heterogeneity in different genomic studies can markedly negatively impact the machine learning classifier’s reproducibility. ComBat normalization improved the prediction performance of machine learning classifier when heterogeneous populations are present, and could successfully remove batch effects within the same population. We also showed that the machine learning classifier’s prediction accuracy can be markedly decreased as the underlying disease model became more different in training and test populations. Comparing different merging and integration methods, we found that merging and integration methods can outperform each other in different scenarios. In the realistic applications, we observed that the prediction accuracy improved when applying ComBat normalization with merging or integration methods in both CRC and TB studies. We illustrated that batch normalization is essential for mitigating both population differences of different studies and batch effects. We also showed that both merging strategy and integration methods can achieve good performances when combined with batch normalization. In addition, we explored the potential of boosting phenotype prediction performance by rank aggregation methods and showed that rank aggregation methods had similar performance as other ensemble learning approaches.
A 2D model to study how secondary growth affects the self-supporting behaviour of climbing plants
Authors: Vecchiato Giacomo , Hattermann Tom , Palladino Michele , Tedone Fabio , Heuret Patrick , Rowe Nick P. , Marcati Pierangelo
Published: October 2023

Climbing plants exhibit specialized shoots, called “searchers”, to cross spaces and alternate between spatially discontinuous supports in their natural habitats. To achieve this task, searcher shoots combine both primary and secondary growth processes of their stems in order to support, orientate and explore their extensional growth into the environment. Currently, there is an increasing interest in developing models to describe plant growth and posture. However, the interactions between the sensing activity (e.g. photo-, gravi-, proprioceptive sensing) and the elastic responses are not yet fully understood. Here, we aim to model the extension and rigidification of searcher shoots. Our model defines variations in the radius (and consequently in mass distribution) along the shoot based on experimental data collected in natural habitats of two climbing species: Trachelospermum jasminoides (Lindl.) Lem. and Condylocarpon guianense Desf.. Using this framework, we predicted the sensory aspect of a plant, that is, the plant’s response to external stimuli, and the plant’s proprioception, that is, the plant’s “self-awareness”. The results suggest that the inclusion of the secondary growth in a model is fundamental to predict the postural development and self-supporting growth phase of shoots in climbing plants.
Establishing brain states in neuroimaging data
Authors: Dezhina Zalina , Smallwood Jonathan , Xu Ting , Turkheimer Federico E. , Moran Rosalyn J. , Friston Karl J. , Leech Robert , Fagerholm Erik D.
Published: October 2023

The definition of a brain state remains elusive, with varying interpretations across different sub-fields of neuroscience—from the level of wakefulness in anaesthesia, to activity of individual neurons, voltage in EEG, and blood flow in fMRI. This lack of consensus presents a significant challenge to the development of accurate models of neural dynamics. However, at the foundation of dynamical systems theory lies a definition of what constitutes the ’state’ of a system—i.e., a specification of the system’s future. Here, we propose to adopt this definition to establish brain states in neuroimaging timeseries by applying Dynamic Causal Modelling (DCM) to low-dimensional embedding of resting and task condition fMRI data. We find that ~90% of subjects in resting conditions are better described by first-order models, whereas ~55% of subjects in task conditions are better described by second-order models. Our work calls into question the status quo of using first-order equations almost exclusively within computational neuroscience and provides a new way of establishing brain states, as well as their associated phase space representations, in neuroimaging datasets.
The RgaS-RgaR two-component system promotes Clostridioides difficile sporulation through a small RNA and the Agr1 system
Authors: Edwards Adrianne N. , McBride Shonna M.
Published: October 2023

The ability to form a dormant spore is essential for the survival of the anaerobic pathogen, Clostridioides difficile, outside of the mammalian gastrointestinal tract. The initiation of sporulation is governed by the master regulator of sporulation, Spo0A, which is activated by phosphorylation. Multiple sporulation factors control Spo0A phosphorylation; however, this regulatory pathway is not well defined in C. difficile. We discovered that RgaS and RgaR, a conserved orphan histidine kinase and orphan response regulator, function together as a cognate two-component regulatory system to directly activate transcription of several genes. One of these targets, agrB1D1, encodes gene products that synthesize and export a small quorum-sensing peptide, AgrD1, which positively influences expression of early sporulation genes. Another target, a small regulatory RNA now known as SpoZ, impacts later stages of sporulation through a small hypothetical protein and an additional, unknown regulatory mechanism(s). Unlike Agr systems in many organisms, AgrD1 does not activate the RgaS-RgaR two-component system, and thus, is not responsible for autoregulating its own production. Altogether, we demonstrate that C. difficile utilizes a conserved two-component system that is uncoupled from quorum-sensing to promote sporulation through two distinct regulatory pathways.
A Rab6 to Rab11 transition is required for dense-core granule and exosome biogenesis in Drosophila secondary cells
Authors: Wells Adam , Mendes Cláudia C. , Castellanos Felix , Mountain Phoebe , Wright Tia , Wainwright S. Mark , Stefana M. Irina , Harris Adrian L. , Goberdhan Deborah C. I. , Wilson Clive
Published: October 2023

Secretory cells in glands and the nervous system frequently package and store proteins destined for regulated secretion in dense-core granules (DCGs), which disperse when released from the cell surface. Despite the relevance of this dynamic process to diseases such as diabetes and human neurodegenerative disorders, our mechanistic understanding is relatively limited, because of the lack of good cell models to follow the nanoscale events involved. Here, we employ the prostate-like secondary cells (SCs) of theDrosophilamale accessory gland to dissect the cell biology and genetics of DCG biogenesis. These cells contain unusually enlarged DCGs, which are assembled in compartments that also form secreted nanovesicles called exosomes. We demonstrate that known conserved regulators of DCG biogenesis, including the small G-protein Arf1 and the coatomer complex AP-1, play key roles in making SC DCGs. Using real-time imaging, we find that the aggregation events driving DCG biogenesis are accompanied by a change in the membrane-associated small Rab GTPases which are major regulators of membrane and protein trafficking in the secretory and endosomal systems. Indeed, a transition fromtrans-Golgi Rab6 to recycling endosomal protein Rab11, which requires conserved DCG regulators like AP-1, is essential for DCG and exosome biogenesis. Our data allow us to develop a model for DCG biogenesis that brings together several previously disparate observations concerning this process and highlights the importance of communication between the secretory and endosomal systems in controlling regulated secretion.
Pulmonary haemorrhage as a frequent cause of death among patients with severe complicated Leptospirosis in Southern Sri Lanka
Authors: Fonseka Chathuranga Lakmal , Dahanayake Niroshana Jathun , Mihiran Denagama J. D. , Wijesinghe Kalani Mithunika , Liyanage Lakshani Nawanjana , Wickramasuriya Hesaru S. , Wijayaratne Gaya Bandara , Sanjaya Kelum , Bodinayake Champica K.
Published: October 2023

Background

Leptospirosis is a tropical disease associated with life threatening complications. Identifying clinical and investigation-based parameters that predict mortality and morbidity is vital to provide optimal supportive care

Methods

We conducted an observational study in an endemic setting, in the southern Sri Lanka. Consecutive patients having complicated leptospirosis were recruited over 18 months. Clinical, investigational and treatment data were collected and the predictors of mortality were analysed.

Results

Out of 88 patients having complicated leptospirosis, 89% were male. Mean age was 47yrs (±16.0). Among the total major complications 94.3% had acute kidney injury, 38.6% pulmonary haemorrhages, 12.5% fulminant hepatic failure, 60.2% hemodynamic instability and 33% myocarditis. An acute significant reduction of haemoglobin (Hb) was observed in 79.4% of patients with pulmonary haemorrhage. The mean of the highest haemoglobin reduction in patients with pulmonary haemorrhage was 3.1g/dL. The presence of pulmonary haemorrhage (PH) and hemodynamic instability within first 48 hours of admission significantly predicted mortality (p<0.05) in severe leptospirosis. Additionally, within first 48 hours of admission, elevated SGOT (AST), presence of atrial fibrillation, presence of significant haemoglobin reduction, higher number of inotropes used, prolonged shock, invasive ventilation and admission to ICU significantly predicted mortality. Out of major complications during the first week after admission, pulmonary haemorrhage and fulminant hepatic failure (FHF) combination had significant adjusted odds of mortality (OR = 6.5 and 4.8, p<0.05). Six patients with severe respiratory failure due to PH underwent ECMO and four survived. The overall mortality in complicated leptospirosis was 17%. In PH and FHF, the mortality rate was higher reaching 35.4% and 54.5%, respectively.

Conclusions

Within first 48 hours of admission, major complications such as pulmonary haemorrhage and haemodynamic instability and other parameters such as atrial fibrillation, acute haemoglobin reduction, elevated SGOT level could be used as early parameters predictive of mortality in severe leptospirosis. PH and FHF during the first week of admission in leptospirosis are associated with high morbidity and mortality requiring prolonged ICU care and hospitalisation. Above parameters could be used as parameters indicating severity for triaging and intensifying treatment. Using ECMO is a plausible treatment option in patients with severe pulmonary haemorrhage.
Detection of multiple human enteropathogens in Norway rats (Rattus norvegicus) from an under-resourced neighborhood of Vancouver, British Columbia
Authors: Lee Lisa K. F. , Himsworth Chelsea G. , Byers Kaylee A. , Atwal Harveen K. , Gabaldon Gus , Ritchie Gordon , Lowe Christopher F. , Matic Nancy , Chorlton Samuel , Hoang Linda , Wobeser Bruce K. , Leung Victor
Published: October 2023

Urban Norway rats (Rattus norvegicus) can carry various human pathogens, and may be involved in pathogen propagation and transmission to humans. From January 31–August 14, 2021, a community outbreak ofShigella flexneriserotype 2a occurred among unhoused or poorly housed people in the Downtown Eastside neighborhood of Vancouver, British Columbia, Canada. The source could not be identified; however, patients reported contact with rats, and previous studies indicated transmission of rat-associated zoonotic pathogens among the unhoused or poorly housed residents of this neighborhood. The study objective was to determine if rats trapped in the outbreak area were carriers ofShigellaspp. and other zoonotic enteric pathogens. From March 23–April 9, 2021, 22 rats were lethally trapped within the outbreak area. Colonic content was analyzed using the BioFire FilmArray Gastrointestinal (multiplex PCR) panel for human enteropathogens, which detected:Campylobacterspp. (9/22),Clostridioides difficile(3/22),Yersinia enterocolitica(5/22),Cryptosporidiumspp. (8/22),Giardia duodenalis(5/22), Rotavirus A (1/22), enteroaggressiveEscherichia coli(2/22), enteropathogenicE.coli(10/22), andShigellaspp. or enteroinvasiveE.coli(EIEC) (3/22). AnipaHPCR assay was used for targeted detection ofShigellaspp./EIEC, with five rats positive. Two samples contained insertion sites unique toS.flexneriisolated from the human outbreak. This study highlights the potential for rats to carry a broad range of human pathogens, and their possible role in pathogen maintenance and/or transmission.
Seroprevalence and related risk factors of Brucella spp. in livestock and humans in Garbatula subcounty, Isiolo county, Kenya
Authors: Mwatondo Athman , Muturi Mathew , Akoko James , Nyamota Richard , Nthiwa Daniel , Maina Josphat , Omolo Jack , Gichuhi Stephen , Mureithi Marianne W. , Bett Bernard
Published: October 2023

Background

Brucellosis is a neglected zoonotic disease that affects both animals and humans, causing debilitating illness in humans and socio-economic losses in livestock-keeping households globally. The disease is endemic in many developing countries, including Kenya, but measures to prevent and control the disease are often inadequate among high-risk populations. This study aimed to investigate the human and livestock seroprevalence of brucellosis and associated risk factors of Brucella spp. in a pastoralist region of northern Kenya.

Methods

A cross-sectional survey was conducted using a two-stage cluster sampling method to select households, livestock, and humans for sampling. Blood samples were collected from 683 humans and 2157 animals, and Brucella immunoglobulin G (IgG) antibodies were detected using enzyme-linked immunosorbent assays. A structured questionnaire was used to collect data on potential risk factors associated with human and animal exposures. Risk factors associated with Brucella spp. exposures in humans and livestock were identified using Multivariate logistic regression.

Results

The results indicated an overall livestock Brucella spp. seroprevalence of 10.4% (95% Confidence Interval (CI): 9.2–11.7). Camels had the highest exposure rates at 19.6% (95% CI: 12.4–27.3), followed by goats at 13.2% (95% CI: 9.3–17.1), cattle at 13.1% (95% CI: 11.1–15.3) and sheep at 5.4% (95% CI: 4.0–6.9). The herd-level seroprevalence was 51.7% (95% CI: 47.9–55.7). Adult animals (Adjusted Odds Ratio (aOR) = 2.3, CI: 1.3–4.0), female animals (aOR = 1.7, CI: 1.1–2.6), and large herd sizes (aOR = 2.3, CI: 1.3–4.0) were significantly associated with anti-brucella antibody detection while sheep had significantly lower odds of Brucella spp. exposure compared to cattle (aOR = 1.3, CI: 0.8–2.1) and camels (aOR = 2.4, CI: 1.2–4.8). Human individual and household seroprevalences were 54.0% (95% CI: 50.2–58.0) and 86.4% (95% CI: 84.0–89.0), respectively. Significant risk factors associated with human seropositivity included being male (aOR = 2.1, CI:1.3–3.2), residing in Sericho ward (aOR = 1.6, CI:1.1–2.5) and having no formal education (aOR = 3.0, CI:1.5–5.9). There was a strong correlation between human seropositivity and herd exposure (aOR = 1.6, CI:1.2–2.3).

Conclusions

The study provides evidence of high human and livestock exposures to Brucella spp. and identifies important risk factors associated with disease spread. These findings emphasize the need for targeted prevention and control measures to curb the spread of brucellosis and implement a One Health surveillance to ensure early detection of the disease in Isiolo County, Northern Kenya.
Identifying key factors contributing to treatment costs for snakebite envenoming in private tertiary healthcare settings in Tamil Nadu, India
Authors: Salim Anika , Williams Jarred , Abdel Wahab Samir , Adeshokan Tade , Almeida José R. , Williams Harry F. , Vaiyapuri Rajendran , Senthilkumaran Subramanian , Thirumalaikolundusubramanian Ponniah , Patel Ketan , Baksh M. Fazil , Lewin Matthew R. , Vaiyapuri Sakthivel
Published: October 2023

Background

India suffers ~58,000 annual deaths due to snakebites. The ‘Big Four’ snakes (Russell’s viper, Indian cobra, common krait, and saw-scaled viper) that are responsible for most bites cause diverse clinical effects. Delayed treatment increases the risk of serious complications and treatment costs. Although government hospitals offer free treatment for snakebites in India, most patients opt for private healthcare, which is an out-of-pocket expense as they often lack health insurance coverage. This study aims to analyse snakebite treatment costs in private tertiary care hospitals in Tamil Nadu, India and identifies the key factors contributing to treatment costs.

Methodology/Principal findings

The treatment cost details for 913 snakebite victims were collected from 10 private tertiary care hospitals across Tamil Nadu. The data were classified into hospital, pharmacy, investigation, and laboratory costs, and analysed to determine various factors that contribute to the costs. The results demonstrate that the average treatment costs vary widely for different snakes. The hospital and pharmacy costs are higher than investigation and laboratory costs for all snakebites. Notably, Russell’s viper bites cost significantly more than the bites from other snakes. Overall, the type of snake, nature of complications, specialist treatments required, and arrival time to hospitals were identified as some of the key factors for higher treatment costs.

Conclusions/Significance

These data demonstrate that ~80% of snakebite patients can be treated with INR 100,000 (~GBP 1000 or USD 1200) or less. This study emphasises the urgent need to improve rural medical care by providing appropriate training for healthcare professionals and essential resources to facilitate early assessment of patients, administer the initial dose of antivenom and refer the patients to tertiary care only when needed. Moreover, the outcome of this study forms a basis for developing appropriate policies to regulate snakebite treatment costs and provide affordable medical insurance for vulnerable communities.
Joint duration-cost-quality optimization model for complex product supply chains under contingency conditions
Authors: Li Yunzhe , Dong Peng , Ye Weimin
Published: October 2023

The Graphical Evaluation and Review Technique (GERT) and complex networks are used to simulate and analyse complex product supply chain networks based on the characteristics of complex product supply chain networks. And the traditional GERT is improved by constructing a grey parametric GERT network with restricted output results, taking into account the fact that the duration, product quality and product cost of each supplier in a complex product supply chain are interval values rather than definite values, and that customers have restrictions on the duration, product quality and product cost of the final product. The functional relationship between product quality, product cost and duration is analysed, and two satisfaction functions for duration and cost are constructed in order to quantify the multi-objective requirements of shortening duration, saving product cost and guaranteeing product quality for complex products under emergency situations. Then, a duration-cost-quality model for complex product supply chains in contingency situations is constructed to obtain the better duration, product cost and product quality of each supplier by optimising the indicator parameters in the network. Finally, the scientific validity and effectiveness of the model and method are verified by means of arithmetic example. The results show that the method is able to analyse the optimal duration, product quality and product cost of each supplier, and the main manufacturer can obtain an optimised combination of duration, cost and quality for a complex product supply chain in different contingency situation. To further promote the sustainable and secure development of complex product supply chains, this paper also suggests the integration of data sharing and blockchain technology with complex product supply chains to develop dynamic supply chain feedback management systems.
Ageing in place or stuck in place: Preferred care setting for community-dwelling older persons in a low-resource country in Sub Saharan Africa
Authors: Cadmus Eniola Olubukola , Adebusoye Lawrence Adekunle , Owoaje Eme Theodora
Published: October 2023

Background

Ageing in Place is the emerging social policy drive for long-term care coordination of older persons globally. This decision may be the only viable option in many low- and middle-income countries like Nigeria. Nevertheless, the risk of older persons being ‘stuck in place’ is high if their preferences are not considered or other alternatives are neither acceptable nor available. This study determined factors associated with the preferred care setting among community-dwelling older persons and explored their views about their choices.

Methods

The study utilised a mixed-methods approach. Participants were older persons (≥ 60 years) in a selected rural and urban community in Oyo State, south-western Nigeria. Quantitative data were collected using an interviewer-administered, semi-structured questionnaire and analysed using Stata version 14 at p<0.05. Qualitative data collection involved 22 Focus Group Discussions (FGD). The discussions were audiotaped, transcribed verbatim and analysed thematically using ATLAS.ti version 8. Selected quotations were used to illustrate themes.

Results

1,180 participants (588 rural vs 592 urban) were interviewed with a mean age of 73.2 ±9.3 years. More rural participants preferred to AIP (61.6%) compared to urban participants (39.2%), p = 0.001. Factors associated with the decision for rural participants were older age [OR:2.07 (95%CI:1.37–3.14)], being male [OR:2.41(95%CI:1.53–3.81)] and having assistance at home [OR:1.79 (95%CI:1.15–2.79)]. In comparison, significant factors for urban participants were older age (≥70years) [OR:1.54(95%CI:1.03–2.31)] and home-ownership [OR:5.83 (95%CI:3.82–8.91)]. The FGD revealed that the traditional expectation of reciprocity of care mostly influenced the desire to AIP. Advantages include improved social connectedness, quality of care, community participation and reduced isolation. Interestingly, participants were not opposed to the option of institutional care.

Conclusion

Ageing in place is preferred and influenced by advanced age and home ownership in our setting. Information provided could guide age-friendly housing policies and community-based programmes for the care of older persons.
Prevalence and determinants of hypertension among older adults: A comparative analysis of the 6th and 8th national health surveys of Bangladesh
Authors: Ghosh Probir Kumar , Harun Md. Golam Dostogir , Shanta Ireen Sultana , Islam Ausraful , Jannat Kaniz Khatun E. , Mannan Haider
Published: October 2023

Background

Hypertension is a major public health concern in low-and middle-income countries. A nationwide Health, Population, and Nutrition Sector Development Program in Bangladesh has been shown to be effective in resource-poor settings. This article aims to investigate whether the prevalence and determinants of adult hypertension changed from 2011 to 2018.

Methods

The determinants of adult hypertension were assessed in 2011 and 2018 data of Bangladesh Demographic and Health surveys. These two surveys included both men and women over the age of 34 years and measured their blood pressure, weight, height, and other covariates. For both surveys, we estimated the age-standard prevalence of hypertension and relative, attributable and mediated risk of determinants of hypertension using hierarchical mixed-effects sequential Poisson regression models.

Results

The prevalence of adult hypertension increased by 10.9% from 29.5% in 2011 to 40.4% in 2018. The nationwide awareness program on the Health, Population and Nutrition Sector changed the risks associated with hypertension determinants over the years. During 2011, Socio-economic status (SES) was a major distal determinant of adult hypertension, explaining 21% of population-attributable risk (ART). However, other factors accounted for 90% of risk, mainly by excessive body weight (51%) and awareness of hypertension (39%). In contrast, SES only explained 16% of ART risk, with 97% of the risk mediated by excessive body weight (55%) and awareness of hypertension (41%).

Conclusion

The study results highlight that hypertension among older adult was significantly increased over the six-year period. Specially, the socio-economic status, awareness of hypertension and excessive body weight were the significant determinants. Being awareness of hypertension and excessive body weight changed the causal pathways of socio-economic status. The results also highlight the value of studying the effect of non-communicable disease awareness programs to enhance our comprehension of factors influencing health.
Loss of heme oxygenase 2 causes reduced expression of genes in cardiac muscle development and contractility and leads to cardiomyopathy in mice
Authors: Cetin-Atalay Rengul , Meliton Angelo Y. , Ozcan Cevher , Woods Parker S. , Sun Kaitlyn A. , Fang Yun , Hamanaka Robert B. , Mutlu Gökhan M.
Published: October 2023

Obstructive sleep apnea (OSA) is a common breathing disorder that affects a significant portion of the adult population. In addition to causing excessive daytime sleepiness and neurocognitive effects, OSA is an independent risk factor for cardiovascular disease; however, the underlying mechanisms are not completely understood. Using exposure to intermittent hypoxia (IH) to mimic OSA, we have recently reported that mice exposed to IH exhibit endothelial cell (EC) activation, which is an early process preceding the development of cardiovascular disease. Although widely used, IH models have several limitations such as the severity of hypoxia, which does not occur in most patients with OSA. Recent studies reported that mice with deletion of hemeoxygenase 2 (Hmox2-/-), which plays a key role in oxygen sensing in the carotid body, exhibit spontaneous apneas during sleep and elevated levels of catecholamines. Here, using RNA-sequencing we investigated the transcriptomic changes in aortic ECs and heart tissue to understand the changes that occur in Hmox2-/- mice. In addition, we evaluated cardiac structure, function, and electrical properties by using echocardiogram and electrocardiogram in these mice. We found that Hmox2-/- mice exhibited aortic EC activation. Transcriptomic analysis in aortic ECs showed differentially expressed genes enriched in blood coagulation, cell adhesion, cellular respiration and cardiac muscle development and contraction. Similarly, transcriptomic analysis in heart tissue showed a differentially expressed gene set enriched in mitochondrial translation, oxidative phosphorylation and cardiac muscle development. Analysis of transcriptomic data from aortic ECs and heart tissue showed loss of Hmox2 gene might have common cellular network footprints on aortic endothelial cells and heart tissue. Echocardiographic evaluation showed that Hmox2-/- mice develop progressive dilated cardiomyopathy and conduction abnormalities compared to Hmox2+/+ mice. In conclusion, we found that Hmox2-/- mice, which spontaneously develop apneas exhibit EC activation and transcriptomic and functional changes consistent with heart failure.
Bioinformatic analysis identified novel candidate genes with the potentials for diagnostic blood testing of primary biliary cholangitis
Authors: Pham Hoang Nam , Pham Linh , Sato Keisaku
Published: October 2023

Primary biliary cholangitis (PBC) is an autoimmune disorder characterized by intrahepatic bile duct destruction and cholestatic liver injury. Diagnosis of PBC is generally based on the existence of anti-mitochondrial antibody (AMA) in blood samples; however, some PBC patients are negative for serum AMA tests, and invasive liver histological testing is required in rare PBC cases. The current study seeks novel candidate genes that are associated with PBC status and have potentials for blood diagnostic testing. Human transcriptomic profiling data of liver and blood samples were obtained from Gene Expression Omnibus (GEO). Three GEO data series (GSE79850, GSE159676, and GSE119600) were downloaded, and bioinformatic analyses were performed. Various differentially expressed genes were identified in three data series by comparing PBC patients and control individuals. Twelve candidate genes were identified, which were upregulated in both liver tissues and blood samples of PBC patients in all three data series. The enrichment analysis demonstrated that 8 out of 12 candidate genes were associated with biological functions, which were closely related to autoimmune diseases including PBC. Candidate genes, especially ITGAL showed good potentials to distinguish PBC with other diseases. These candidate genes could be useful for diagnostic blood testing of PBC, although further clinical studies are required to evaluate their potentials as diagnostic biomarkers.
Blood inflammatory markers and mortality in the US population: A Health and Retirement Survey (HRS) analysis
Authors: Kalair Attiya , Pavan Matilde , Alpert Naomi , Ghaffari Saghi , Taioli Emanuela
Published: October 2023

A potential direct correlation between systemic inflammation and physiological aging has been suggested, along with whether there is a higher expression of inflammatory markers in otherwise healthy older adults. Cross-sectional data were extracted from the publicly available 2016 Health and Retirement Survey, a nationally representative survey of older adults in the United States. A subset of participants (n = 9934) consented to a blood draw at the time of recruitment and were measured for high sensitivity C-reactive protein (hs-CRP), Interleukin (IL-6, IL-10, IL-1RA), soluble tumor necrosis factor receptor (sTNFR-1) and transforming growth factor beta 1 (TGF-β1). We included 9,188 participants, representative of 83,939,225 nationally. After adjusting for sex and the number of comorbidities, there remained a significant positive correlation between age and ln (log adjusted) IL-6, and ln sTNFR-1, and a significant inverse correlation between age and ln IL-1RA, ln TGF-β1, and ln hs-CRP. Among the subset of participants who reported none of the available comorbidities (n = 971), there remained an independent correlation of age with ln IL-6 and ln sTNFR-1. After adjusting for age, sex, and number of reported comorbidities, there was a statistically significant correlation between increased ln IL-6, ln IL-10, ln sTNFR-1, and ln hs-CRP with death. This study highlights the existence of a correlation between serum biomarkers of inflammation and aging, not only in the whole population, but also in the smaller subset who reported no comorbidities, confirming the existence of a presence of low-grade inflammation in aging, even in healthy elders. We also highlight the existence of a correlation between inflammatory markers and overall mortality. Future studies should address a possible threshold of systemic inflammation where mortality significantly increases, as well as explore the effectiveness of anti-inflammatory treatments on morbidity and mortality in healthy aging subjects.