bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring the pre-inflationary dynamics in loop quantum cosmology with a DBI scalar field
Authors: Mohammadi Abolhassan
Published: October 2024

Loop quantum cosmology is a symmetry-reduced application of loop quantum gravity. The theory predicts a bounce for the universe at the Planck scale and resolves the singularity of standard cosmology. The dynamics is also governed by an effective Hamiltonian, which predicts a modified Friedmann equation containing the quadratic terms of the energy density. The term plays an essential role in the high energy regime, but the equations return to the standard form in the low energy regime. The evolution of the universe in the pre-inflationary period is studied in the framework of loop quantum cosmology, where the DBI scalar field is assumed to be the dominant component of the universe. Using the numerical method, we provide the evolution of the DBI field. The background evolution shows that there are three phases as: bouncing phase, transition phase and slow-roll inflationary phase. There is also a short period of super-inflation just at the beginning of the bounce phase. The field first climbs the potential and then reaches the turning point where ϕ̇ disappears and the potential energy becomes the dominant part of the energy density. This is the time when the slow roll inflation begins and the field slowly rolls down the potential. The results indicate that there are a few e-fold expansions in the bounce phase, about N = 3.5–4, and the universe experiences about N = 59 e-fold expansions in the slow-roll inflation phase.
Geometric neural network based on phase space for BCI-EEG decoding
Authors: Carrara Igor , Aristimunha Bruno , Corsi Marie-Constance , de Camargo Raphael Y , Chevallier Sylvain , Papadopoulo Théodore
Published: October 2024

Objective. The integration of Deep Learning (DL) algorithms on brain signal analysis is still in its nascent stages compared to their success in fields like Computer Vision. This is particularly true for Brain–computer interface (BCI), where the brain activity is decoded to control external devices without requiring muscle control. Electroencephalography is a widely adopted choice for designing BCI systems due to its non-invasive and cost-effective nature and excellent temporal resolution. Still, it comes at the expense of limited training data, poor signal-to-noise, and a large variability across and within-subject recordings. Finally, setting up a BCI system with many electrodes takes a long time, hindering the widespread adoption of reliable DL architectures in BCIs outside research laboratories. To improve adoption, we need to improve user comfort using, for instance, reliable algorithms that operate with few electrodes. Approach. Our research aims to develop a DL algorithm that delivers effective results with a limited number of electrodes. Taking advantage of the Augmented Covariance Method and the framework of SPDNet, we propose the Phase-SPDNet architecture and analyze its performance and the interpretability of the results. The evaluation is conducted on 5-fold cross-validation, using only three electrodes positioned above the Motor Cortex. The methodology was tested on nearly 100 subjects from several open-source datasets using the Mother Of All BCI Benchmark framework. Main results. The results of our Phase-SPDNet demonstrate that the augmented approach combined with the SPDNet significantly outperforms all the current state-of-the-art DL architecture in MI decoding. Significance. This new architecture is explainable and with a low number of trainable parameters.
Identification of perceived sentences using deep neural networks in EEG
Authors: Valle Carlos , Mendez-Orellana Carolina , Herff Christian , Rodriguez-Fernandez Maria
Published: October 2024

Objetive. Decoding speech from brain activity can enable communication for individuals with speech disorders. Deep neural networks (DNNs) have shown great potential for speech decoding applications. However, the limited availability of large datasets containing neural recordings from speech-impaired subjects poses a challenge. Leveraging data from healthy participants can mitigate this limitation and expedite the development of speech neuroprostheses while minimizing the need for patient-specific training data. Approach. In this study, we collected a substantial dataset consisting of recordings from 56 healthy participants using 64 EEG channels. Multiple neural networks were trained to classify perceived sentences in the Spanish language using subject-independent, mixed-subjects, and fine-tuning approaches. The dataset has been made publicly available to foster further research in this area. Main results. Our results demonstrate a remarkable level of accuracy in distinguishing sentence identity across 30 classes, showcasing the feasibility of training DNNs to decode sentence identity from perceived speech using EEG. Notably, the subject-independent approach rendered accuracy comparable to the mixed-subjects approach, although with higher variability among subjects. Additionally, our fine-tuning approach yielded even higher accuracy, indicating an improved capability to adapt to individual subject characteristics, which enhances performance. This suggests that DNNs have effectively learned to decode universal features of brain activity across individuals while also being adaptable to specific participant data. Furthermore, our analyses indicate that EEGNet and DeepConvNet exhibit comparable performance, outperforming ShallowConvNet for sentence identity decoding. Finally, our Grad-CAM visualization analysis identifies key areas influencing the network’s predictions, offering valuable insights into the neural processes underlying language perception and comprehension. Significance. These findings advance our understanding of EEG-based speech perception decoding and hold promise for the development of speech neuroprostheses, particularly in scenarios where subjects cannot provide their own training data.
Reducing power requirements for high-accuracy decoding in iBCIs
Authors: Karpowicz Brianna M , Bhaduri Bareesh , Nason-Tomaszewski Samuel R , Jacques Brandon G , Ali Yahia H , Flint Robert D , Bechefsky Payton H , Hochberg Leigh R , AuYong Nicholas , Slutzky Marc W , Pandarinath Chethan
Published: October 2024

Objective. Current intracortical brain-computer interfaces (iBCIs) rely predominantly on threshold crossings (‘spikes’) for decoding neural activity into a control signal for an external device. Spiking data can yield high accuracy online control during complex behaviors; however, its dependence on high-sampling-rate data collection can pose challenges. An alternative signal for iBCI decoding is the local field potential (LFP), a continuous-valued signal that can be acquired simultaneously with spiking activity. However, LFPs are seldom used alone for online iBCI control as their decoding performance has yet to achieve parity with spikes. Approach. Here, we present a strategy to improve the performance of LFP-based decoders by first training a neural dynamics model to use LFPs to reconstruct the firing rates underlying spiking data, and then decoding from the estimated rates. We test these models on previously-collected macaque data during center-out and random-target reaching tasks as well as data collected from a human iBCI participant during attempted speech. Main results. In all cases, training models from LFPs enables firing rate reconstruction with accuracy comparable to spiking-based dynamics models. In addition, LFP-based dynamics models enable decoding performance exceeding that of LFPs alone and approaching that of spiking-based models. In all applications except speech, LFP-based dynamics models also facilitate decoding accuracy exceeding that of direct decoding from spikes. Significance. Because LFP-based dynamics models operate on lower bandwidth and with lower sampling rate than spiking models, our findings indicate that iBCI devices can be designed to operate with lower power requirements than devices dependent on recorded spiking activity, without sacrificing high-accuracy decoding.
User-wise perturbations for user identity protection in EEG-based BCIs
Authors: Chen Xiaoqing , Li Siyang , Tu Yunlu , Wang Ziwei , Wu Dongrui
Published: October 2024

Objective. An electroencephalogram (EEG)-based brain–computer interface (BCI) is a direct communication pathway between the human brain and a computer. Most research so far studied more accurate BCIs, but much less attention has been paid to the ethics of BCIs. Aside from task-specific information, EEG signals also contain rich private information, e.g. user identity, emotion, disorders, etc which should be protected. Approach. We show for the first time that adding user-wise perturbations can make identity information in EEG unlearnable. We propose four types of user-wise privacy-preserving perturbations, i.e. random noise, synthetic noise, error minimization noise, and error maximization noise. After adding the proposed perturbations to EEG training data, the user identity information in the data becomes unlearnable, while the BCI task information remains unaffected. Main results. Experiments on six EEG datasets using three neural network classifiers and various traditional machine learning models demonstrated the robustness and practicability of the proposed perturbations. Significance. Our research shows the feasibility of hiding user identity information in EEG data without impacting the primary BCI task information.
Modeling and Analysis of MEMS Electrostatic Energy Harvesting System
Authors: Karthik Reddy G , Singh Pulkit , Ravi Kiran Chand , Anusha B , Gowri Chaduvula , Vivek R
Published: October 2024

Energy harvesting generators for low-power wireless electronic devices have drawn more attention in recent years. The design and analysis of a MEMS energy harvester based on electrostatic transduction are discussed in this study. Because a folded beam design has the advantage of being able to move huge dimensions, be compliant in the desired direction, and stiffer in the orthogonal direction. Large displacement of the energy harvester’s proof mass results in improved performance. The spice circuit of the harvester has been modelled and performed simulation to evaluate the output power of the harvester in LTSPICE. FEM simulations using COMSOL were used to assess the natural frequency and mode shape of the system and compare results with those of analytically determined values.
Dirac points and inverse problems of quantum graphs associated with Archimedean tilings
Authors: Jatulan Eduardo O , Law Chun-Kong
Published: October 2024

One interesting phenomenon of graphene is the presence of the conical singularity or Dirac points. Using the quantum graph model, we show that there exist three classes of possible Dirac points for all of the periodic quantum graphs associated with Archimedean tilings, when the potentials are identical and even. They occur at the periodic eigenvalues, anti-periodic eigenvalues, and other double eigenvalues of the dispersion relations, respectively. We also characterize their associated potentials. Moreover, we show that there are no other possible Dirac points. Our work is systematic and rigorous. Finally, we solve an inverse spectral problem for the potential, given the knowledge of the pure point and absolutely continuous spectra.
Data Models for Casting Processes – Performances, Validations and Challenges
Authors: Horr A M , Gómez Vázquez R , Blacher D
Published: October 2024

Data-driven models with their associated data learning and training schemes can be utilised for the light metal casting processes. This paper presents the basis of data model building processes along with data training and learning exercises for vertical direct chill casting and high pressure die casting (HPDC) applications. The concepts of efficient database building, data translations and sampling, as well as real-time model building and validations are briefly discussed. Rigorous performance studies were additionally carried out for two real-world case studies. Different combinations of data solvers and interpolators are adapted for the model building techniques, while machine learning schemes are used for data trainings.
Effect of welding gas mixtures on weld material and bead geometry
Authors: Unger Michael , Neves José L. , Schnall Martin
Published: October 2024

Shielding gas is an essential parameter in welding processes, serves to shield the molten material from the atmosphere and external contaminations while providing a stable electric-arc pathway during the process, thus influencing the quality of the weld bead and several other aspects of the process. Therefore, any welding-based process, such as wire-arc additive manufacturing, could benefit from shielding gas mixture optimisation to selectively improve the processing and possibly the final mechanical properties of the welded material. In this study welding of EN AW 5183 aluminium (single weld bead and wire-arc additive manufacturing build-up) was conducted using several gas mixtures and their influence on final geometry defects, and microstructure measured. The gas mixtures used were a combination of varying amounts of carbon dioxide, nitrogen, and oxygen. These were added to commercially available argon gas. It was observed that: CO2 additions led to an unfavourable bonding defect and increased mean grain size; nitrogen additions caused a decrease in mean grain size, decreased pore count while maintaining a similar pore volume fraction to the reference argon mixture samples; oxygen additions showed slight reduction of mean grain size, decreased pore count and decreased pore volume fraction. These results further showcase that varying shielding gas mixtures influence the final material properties and should be considered as an additional improvement route for conventional welding and additive manufacturing.
Overview on aluminium alloys as sinks for end-of-life vehicle scrap
Authors: Pogatscher Stefan , Samberger Sebastian
Published: October 2024

A fundamental principle in metallurgy is that the higher the purity of metals and alloys, the more favourable their properties will be. However, as the recycling of materials in production becomes increasingly significant, the levels of impurities are also on the rise. In the case of aluminium, the consequences can be detrimental due to the low solubility of most elements in this metal, which leads to the formation of brittle intermetallic phases (IMPs). Moreover, once impurities have entered aluminium, it is difficult to remove them. In 2017, almost 100 million cars were produced worldwide. Historically, vehicle design prioritised performance, resulting in a multi-material mix to utilise the best materials for each application. This included over 40 different wrought and cast aluminium alloys, Cu-based materials for electrics, and steels for high-strength applications. In the recycling of end-of-life vehicles (ELVs), high purity wrought Al alloys are today down-cycled to low purity cast engine blocks. However, recent advancements show that the drawback of increase IMP-fractions can be turned into benefits through the strategic design of heterostructured alloys. A first successful alloy example from this approach enables interesting forming properties, previously only found in 5xxx series wrought aluminium alloys, in combination with a matrix composition and age-hardening potential known from 6xxx series wrought aluminium alloys. A second examples reviews compositions directly resulting from ELV scrap. By manipulating IMPs it is feasible to create heterostructures with an interesting balance of strength and ductility. These approaches challenge traditional views, allowing for a greater volume fraction of intermetallic phases. Understanding the formation and role of intermetallic particles is crucial. This work gives an overview to the current problem and the state of the art and addressed the potential of upcycled aluminium alloys that tolerate high impurity levels by using intermetallic phases as impurity sinks.
A prairie dog optimization (PDO)-based MPPT technique under partial and complex partial shading conditions
Authors: M Vishnu Priya , G Anand Kumar , K Premkumar
Published: October 2024

This study deals with the new algorithm known as prairie dog optimization (PDO) to improve the performance of the PV system under partial and complex partial conditions. This algorithm is based on the exploration and exploitation behavior of prairie dog. Conventional methods like ‘perturb and observe, cuckoo search optimization (CS), particle swarm optimization (PSO), flower pollination algorithm, and the Grey wolf optimization algorithm are used to compare the performance of the prairie dog optimization (PDO). These algorithms are compared based on tracking efficiency and output power. This analysis is done using MATLAB Simulink under a variety of weather conditions. PDO improves and outperforms other algorithms in terms of performance and capability. The PDO has high efficiency and has produced more output power when compared to other algorithms in this study. A 250 W prototype model is developed to validate the performance of the PDO MPPT. The PDO has outperformed in various weather conditions, the calculation time of PDO algorithm is less, and has zero oscillations at maximum power point, and has a quick convergence rate.
The Death of Darwin and After
Authors: Hewitt Martin
Published: October 2024

The debate over Darwinian evolution in Britain evolved in the fifteen years after Darwin’s death in 1882. It moved into a more ecclesiological phase, in which the dominant struggle seemed to be the precise nature of the ‘true’ Darwinian belief. The late-Victorian generation, born c.1845–59, whose voices became progressively more significant in evolutionary debates as the 1880s progressed, tended to divide into different evolutionary camps: ultra-Darwinians, neo-Darwinians, and Lamarckians (or Spencerians). These discussions, often as heated as earlier disagreements between those for and against Darwin, were pursued alongside the continued scepticism of older generations, and to the discomfort of the high Victorians, who saw them as unnecessarily sectarian. The sense that Darwinian ideas were triumphing encouraged greater attention to their broader implications: in philosophy where Victorian Idealism became inflected with Darwinism, in theology, and in social thought, where late Victorians were much more open to social Darwinist approaches.
Development and validation of a novel tool for identification and categorization of non-technical errors associated with surgical mortality
Authors: Ey Jesse D , Kollias Victoria , Herath Matheesha B , Lee Octavia , Bruening Martin H , Wells Adam J , Maddern Guy J
Published: October 2024

Background

Up to half of all surgical adverse events are due to non-technical errors, making non-technical skill assessment and improvement a priority. No specific tools are available to retrospectively identify non-technical errors that have occurred in surgical patient care. This original study aimed to develop and provide evidence of validity and inter-rater reliability for the System for Identification and Categorization of Non-technical Error in Surgical Settings (SICNESS).

Methods

A literature review, modified Delphi process, and two pilot phases were used to develop and test the SICNESS tool. For each pilot, 12 months of surgical mortality data from the Australian and New Zealand Audit of Surgical Mortality were assessed by two independent reviewers using the SICNESS tool. Main outcomes included tool validation through modified Delphi consensus, and inter-rater reliability for: non-technical error identification and non-technical error categorization using Cohen’s κ coefficient, and overall agreement using Fleiss’ κ coefficient.

Results

Version 1 of the SICNESS was used for pilot 1, including 412 mortality cases, and identified and categorized non-technical errors with strong–moderate inter-rater reliability. Non-technical error exemplars were created and validated through Delphi consensus, and a novel mental model was developed. Pilot 2 included an additional 432 mortality cases. Inter-rater reliability was near perfect for leadership (κ 0.92, 95% c.i. 0.82 to 1.00); strong for non-technical error identification (κ 0.89, 0.84 to 0.93), communication and teamwork (κ 0.89, 0.79 to 0.99), and decision-making (κ 0.85, 0.79 to 0.92); and moderate for situational awareness (κ 0.79, 0.71 to 0.87) and overall agreement (κ 0.69, 0.66 to 0.73).

Conclusion

The SICNESS is a reliable and valid tool, enabling retrospective identification and categorization of non-technical errors associated with death, occurring in real surgical patient interactions.
Lesion and lesion network localization of dysnomia after epilepsy surgery
Authors: Mhanna Asmaa , Bruss Joel , Griffis Joseph C , Sullivan Alyssa W , Kawasaki Hiroto , Binder Jeffrey R , Pillay Sara B , Howard Matthew A , Tranel Daniel , Boes Aaron D
Published: October 2024

Temporal lobe epilepsy surgery is an effective treatment option for patients with drug-resistant epilepsy. However, neurosurgery poses a risk for cognitive deficits—up to one-third of patients have a decline in naming ability following temporal lobe surgery. In this study, we aimed to better understand the neural correlates associated with reduced naming performance after temporal lobe surgery, with the goal of informing surgical planning strategies to mitigate the risk of dysnomia.

We retrospectively identified 85 patients who underwent temporal lobe resective surgery (49 left temporal lobe, 36 right temporal lobe) for whom naming ability was assessed before and >3 months post-surgery using the Boston Naming Test. We used multivariate lesion-symptom mapping to identify resection sites associated with naming decline, and we used lesion network mapping to evaluate the broader functional and structural connectivity profiles of resection sites associated with naming decline. We validated our findings in an independent cohort of 59 individuals with left temporal lobectomy, along with repeating all analyses after combining the cohorts.

Lesion laterality and location were important predictors of post-surgical naming performance. Naming performance significantly improved after right temporal lobectomy (P = 0.015) while a decrement in performance was observed following left temporal lobectomy (P = 0.002). Declines in naming performance were associated with surgical resection of the left anterior middle temporal gyrus (Brodmann area 21, r = 0.41, P < 0.001), along with a previously implicated basal temporal language area. Resection sites linked to naming decline showed a functional connectivity profile featuring a left-lateralized network closely resembling the extended semantic\default mode network, and a structural connectivity profile featuring major temporo-frontal association white matter tracts coursing through the temporal stem.

This extends prior work by implicating the left anterior middle temporal gyrus in naming decline and provides additional support for the role of the previously identified basal temporal language area in naming decline. Importantly, the structural and functional connectivity profiles of these regions suggest they are key nodes of a broader extended semantic network. Together these regional and network findings may help in surgical planning and discussions of prognosis.
Identification of a novel variant of LAMB3 in a patient with a distinct junctional epidermolysis bullosa laryngo-onycho-cutaneous syndrome phenotype
Authors: Suvarnakar Aashka , Kahn Michelle Schwartz , Derrick Kristina M , Kabir Soodeh , Glick Sharon A
Published: October 2024

Laryngo-onycho-cutaneous (LOC) is a rare subtype of junctional epidermolysis bullosa (JEB). We report the case of a girl with congenital LOC JEB with numerous cutaneous eroded plaques, oral ulcers, nail dystrophy and laryngeal involvement phenotypically consistent with this rare subtype and explore the underlying genotype.
2024 results of a United Kingdom and Ireland phototherapy minimal erythema dose survey
Authors: Britton Jason , Verma Prashant
Published: October 2024

This is a summary of minimal erythema dose (MED) practice survey results collected across the UK and Ireland. It is noticeable that there is wide variation in protocols used to measure the irradiance from handheld MED testers. All but one centre are no longer using narrowband ultraviolet B canopies to undertake MED assessments.
A novel method for measuring the direction and angle of central ray and predicting rotation centre via panorama phantom
Authors: Joh Byung-Ju , Lee Sam-Sun , Yeom Han-Gyeol , Jo Gyu-Dong , Kim Jo-Eun , Huh Kyung-Hoe , Yi Won-Jin , Heo Min-Suk
Published: October 2024

The aim of this study is to propose and evaluate a novel method for measuring the central ray direction and detecting the rotation centre of panoramic radiography using the panorama phantom. To determine the central ray direction, 2 points passing through the same x-coordinate in a panoramic radiograph were identified and connected. The angles formed by the central ray with the midline and the angle to the arch form were measured using mathematical calculations. Further, by analysing the continuous changes in the central ray obtained in this manner, the movement of the rotation centre was detected and visualized. The angle between the central ray and the midline exhibited a progressive decrease from the anterior to the posterior direction. With regards to the arch form, the angle of the central ray exhibited an increasing pattern as it moved from the anterior to the posterior direction, culminating in its peak value at the lower second premolar cusp region, followed by a consistent decrease. The rotation centre approximately started from the distolateral aspect of the coronoid process and then anteromedially moved to the midline in a curved line passing between the mandibular notch and coronoid process. By using the panorama phantom, we successfully obtained the central ray direction and detected the rotation centre of the panoramic radiography.
Antennal sensilla of Cyclocephala barrerai (Coleoptera: Melolonthidae): morphology, sexual dimorphism, allometric relationships, and function
Authors: Sanchez-Cruz Abraham , Tapia-Maruri Daniel , Villa-Ayala Patricia , Robledo Norma , Romero-López Angel A , Rojas Julio C , Jiménez-Pérez Alfredo
Published: October 2024

Scarab beetles use pheromones and volatiles to search for their partners and host plants. The perception of these compounds occurs in the beetle antennae, particularly in the sensilla. Relatively few studies have morphologically and physiologically characterized the sensilla of scarab beetles. Cyclocephala barrerai Martínez is a beetle distributed in Mexico. Male beetles have larger antennal lamellae than females, and in both cases, the size of this structure is related to their weight. Previous studies have reported that both sexes are attracted to bacterial volatiles isolated from the female genital chambers. Female cuticular hydrocarbons may act as a sexual contact pheromone. However, antennal sensilla and their electrophysiological responses to behaviorally relevant compounds remain to be investigated. Here, we describe and report the types, allometric relationships, and functions of sensilla found in the lamellae of both C. barrerai sexes. Sensilla were identified, classified, measured, and counted to identify intra and intersexual relationships. The single sensillum recordings showed that plant volatiles, hydrocarbons, and heat stimulated receptor neurons. We identified 2 new types of sensilla basiconica in the scape. Males have more and larger antennal sensilla placodea IV, which specializes in detecting pheromones, plant volatiles, and heat. Females have a greater diversity of sensilla.
The association between tobacco use and COVID-19 diagnoses in three Nordic countries: a pooled analysis
Authors: Shaaban Ahmed Nabil , Andersson Filip , Thiesmeier Robert , Orsini Nicola , Peña Sebastian , Caspersen Ida Henriette , Magnusson Cecilia , Karvonen Sakari , Magnus Per Minor , Hergens Maria Pia , Qazi Basra , Galanti Maria Rosaria
Published: October 2024

Previous research has suggested an unexpected negative association between smoking and susceptibility to COVID-19. This study, drawing on population-based data from three Nordic countries—Sweden, Norway, and Finland—aims to investigate this association further, capitalizing on diversity introduced by different containment measures. The objective of this research was to examine the association between cigarette smoking and snus (smokeless tobacco) use and the risk of confirmed COVID-19 infection. A pooled analysis integrating original data from 547,685 participants across three countries. We used a multiple imputation approach based on conditional probabilities to impute the systematically missing covariates. The associations between tobacco use and COVID-19 infection were assessed, controlling for potential confounding factors. Current cigarette smokers had a lower risk of a confirmed COVID-19 case, whereas there was an increased risk among snus users. Our sensitivity analysis confirmed that the associations between tobacco use and COVID-19 infection risk are robust, remaining consistent regardless of whether covariate imputation was applied. Findings support a negative association between smoking and SARS-CoV-2 infection, but not the hypothesis that nicotine may be protective against the risk of contracting SARS-CoV-2 infection.
Species diversity and network diversity in the human lung cancer tissue microbiomes
Authors: Qiao Yuting , Mei Jiandong , Ma Zhanshan (Sam)
Published: October 2024

This study explores the relationship between microbial diversity and disease status in human lung cancer tissue microbiomes, using a sample size of 1212. Analysis divided the data into primary tumour (PT) and normal tissue (NT) categories. Differences in microbial diversity between PT and NT were significant in 57% of comparisons, although dataset dependence was a factor in the diversity levels. Shared species analysis (SSA) indicated no significant differences between PT and NT in over 90% of comparisons. Network diversity assessments revealed significant differences between NT and PT regarding species relative abundances and network link abundances for q = 0–3. Additionally, significant variations were found between NT and lung squamous cell carcinoma (LUSC) at q = 0. in network link probabilities, illustrating the diversity in species interactions. Our findings suggest a stable overall microbiome diversity and composition in lung cancer patients’ lung tissues despite patients with diagnosed lung tumours, indicating modified microbial interactions within the tumour. These results highlight an association between altered microbiome interaction patterns and lung tumours, offering new insights into the ecological dynamics of lung cancer microbiomes.
Geophysical models integration using principal component analysis: application to unconventional geothermal exploration
Authors: Ars Jean-Michel , Tarits Pascal , Hautot Sophie , Bellanger Mathieu
Published: October 2024

Geophysical data integration covers a wide range of approaches, from visual interpretation of model presented side by side to sophistical statistical analyses such as automatic clustering. We present here a geophysical model integration based on principal component analysis (PCA), which allows to gain insight in a multivariable system. PCA for geophysical models integration define a new set of principal component (PC) models, distributed along new orthogonal axes by solving a eigenvalue problem. We show that PC component models patterns reflect different processes sensed by the geophysical observations. We applied this integration method to models obtained from constrained and joint inversion of gravity, ambient noise and MT data in the framework of unconventional geothermal exploration in Massif Central, France. PCA of the log-resistivity, the density contrast and the Vs velocity model has three independent components. The first one (PC1) representing 69 per cent of the total variance of the system is highly influenced by the parameter coupling enforced in the joint inversion process. PC1 allows to point to geophysical structures that may be related to the geothermal anomaly. The second component (PC2) represents 22 per cent of the total variance and is strongly correlated to the resistivity distribution. PC2 correlation to shallow fault structures suggests that it may be a marker of fracturing. The third component, PC3, accounts for 9 per cent of the total variance and is correlated with velocity structures and anticorrelated with density structures, respectively. The contribution of geophysical properties, mainly sensitive to the elastic properties of rock units, and the good agreement with shallow geological features make PC3 useful for the 3-D description of geological units. This statistical approach helps the interpretation of geophysical models into a limited number of geological processes, one possibly geothermal. Lithology may be derived from PC3, fracturing from PC2 and hydrothermal anomaly from PC1. Nevertheless PCA as a geophysical integration methodology is site-dependent and interpretation relies on a priori knowledge of the local geological mechanisms.
Body-wave speeds and polarizations in the presence of an initial deviatoric stress
Authors: Geng Yichen , Ishii Miaki
Published: October 2024

Body-wave speeds and polarization directions in a homogeneous and isotropic medium can be influenced by the presence of an initial deviatoric stress, which is conventionally ignored in seismic-wave propagation theories. To the first order, the P-wave speed is sensitive to the initial deviatoric stress, and the P-wave polarization has a perturbation perpendicular to the propagation direction. In addition, the S waves travel at two distinct speeds, and the S-wave polarizations are in two orthogonal directions, which are constrained by the initial deviatoric stress and involve a perturbation parallel to the propagation direction. Using a subduction zone setting with an initial deviatoric stress on the order of tens of MPa, the P-wave speed perturbation, S-wave splitting time and polarization perturbation are estimated to be on the order of 0.01 per cent, 0.01 s and 0.01 per cent, respectively. While these effects are too small to be reliably resolved using seismic observations, the theory presented in this paper could be useful for ultrasonic stress measurements in engineering applications.
Exploring cohort-based density-dependent effects on maturity in Norwegian spring-spawning herring (Clupea harengus)
Authors: Vatnehol Sindre , Hølleland Sondre , Salthaug Are , Høines Åge , Slotte Aril , Stenevik Erling Kåre
Published: October 2024

The influence of density-dependent effects on fish maturity is rarely considered when evaluating different harvest strategies, nor when formulating short-term catch advice. In cases where these effects are included, the spawning stock size is commonly used as the density variable. However, this approach is inadequate for a stock where juvenile and mature individuals have limited interaction. In such instances, using the abundance of the recruits of a cohort as a density variable is a more appropriate alternative. In this study, we have used the Norwegian spring-spawning herring (Clupea harengus) as a test stock to investigate this concept and develop a model for predicting future trends in maturity-at-age. This stock is an optimal candidate since previous publications have highlighted a spatial separation between juveniles and adults, and changes in maturity in response to historical stock dynamics have been observed and documented. Our approach provides increased accuracy for predicting maturity-at-age when compared to an assumption of density independence. Furthermore, a further expansion of this approach, i.e. applying a relationship with somatic growth, can contribute to more realistic simulations for predicting future stock dynamics, and more appropriate catch advice.
Experimental and numerical study of the emission of Nox by the addition of isooctane to unleaded commercial gasoline for a spark–ignition engine
Authors: Boubahri Chokri , Meherzi Radhouane , Lendoye Darcy Odounga , Bessrour Jamel , Elleuch Amal
Published: October 2024

The objective of this article is to evaluate, through an experimental and numerical study, the effect of the addition of isooctane on the performance and Nox emissions of a spark–ignition engine four different mixtures in addition to gasoline were tested in a spark–ignition engine using the DIN70020 standard at full load. The tests were conducted by adding 10, 20, 30, and 40% isooctane by volume to unleaded commercial gasoline. This practice makes a significant contribution to improving engine performance, increasing fuel efficiency, and reducing pollutant emissions. As a result, the addition of isooctane is establishing itself as a standard in the manufacture of premium fuels, providing not only an improved driving experience but also preserving the health of the engine. Extensive studies have been conducted to explore the potential of isooctane as a fuel in this regard. NOx emissions were reduced by adding a proportion of isooctane to unleaded commercial gasoline for all fuel blends, which could be explained by the high vaporization enthalpy of isooctane. This reduces the maximum temperature reached in the cylinder and thus reduces nitrogen oxide (NOx) emissions. A significant reduction in emissions of approximately 5% is achieved for the I10 blend (10% isooctane + 90% unleaded commercial gasoline) with the maintenance of engine performance (torque and power). This experimental study is confirmed by a numerical simulation using the DIESL-RK software with an average convergence of results that varies from 0.47% to 5.01%.
Decreased Brain pH Correlated With Progression of Alzheimer Disease Neuropathology: A Systematic Review and Meta-Analyses of Postmortem Studies
Authors: Hagihara Hideo , Miyakawa Tsuyoshi
Published: October 2024

Background

Altered brain energy metabolism is implicated in Alzheimer disease (AD). Limited and conflicting studies on brain pH changes, indicative of metabolic alterations associated with neural activity, warrant a comprehensive investigation into their relevance in this neurodegenerative condition. Furthermore, the relationship between these pH changes and established AD neuropathological evaluations, such as Braak staging, remains unexplored.

Methods

We conducted quantitative meta-analyses on postmortem brain and cerebrospinal fluid pH in patients with AD and non-AD controls using publicly available demographic data. We collected raw pH data from studies in the NCBI GEO, PubMed, and Google Scholar databases.

Results

Our analysis of 20 datasets (723 patient samples and 524 control samples) using a random-effects model showed a significant decrease in brain and cerebrospinal fluid pH in patients compared with controls (Hedges’ g = −0.57, P < .0001). This decrease remained significant after considering postmortem interval, age at death, and sex. Notably, pH levels were negatively correlated with Braak stage, indicated by the random-effects model of correlation coefficients from 15 datasets (292 patient samples and 159 control samples) (adjusted r = −0.26, P < .0001). Furthermore, brain pH enhanced the discriminative power of the APOEε4 allele, the most prevalent risk gene for AD, in distinguishing patients from controls in a meta-analysis of 4 combined datasets (95 patient samples and 87 control samples).

Conclusions

The significant decrease in brain pH in AD underlines its potential role in disease progression and diagnosis. This decrease, potentially reflecting neural hyperexcitation, could enhance our understanding of neurodegenerative pathology and aid in developing diagnostic strategies.
Pendent steady rivulets and droplets: from lubrication to bifurcation
Authors: Grinfeld Michael , Pritchard David
Published: October 2024

We consider the shape of the free surface of steady pendent rivulets (or equivalently, two-dimensional droplets) beneath a planar substrate. We formulate the governing equations in terms of two closely related dynamical systems and use classical phase-plane techniques, in particular time maps, to analyse the bifurcation structure of the problem. Our results explain why lubrication theory is unable to capture this bifurcation structure for pendent rivulets, although it is successful in the related problem of sessile rivulets.
Monkeypox Virus Infection Stimulates a More Robust and Durable Neutralizing Antibody Response Compared to Modified Vaccinia Virus Ankara Vaccination
Authors: Selverian Christopher N , Monticelli Stephanie R , Jaleta Yakin M , Lasso Gorka , DeMouth Megan E , Meola Annalisa , Berrigan Jacob , Batchelor Thomas G , Battini Leandro , Guardado-Calvo Pablo , Herbert Andrew S , Chandran Kartik , Meyerowitz Eric , Miller Emily Happy
Published: October 2024

Monkeypox virus (MPXV) has recently caused a global disease outbreak in humans. Differences in the neutralizing antibody response to vaccination versus MPXV infection remain poorly understood. Here, we examined the neutralization of MPXV and vaccinia virus by sera from a cohort of convalescent and vaccinated individuals at 1 and 8 months postexposure. Convalescent individuals displayed higher neutralizing antibody titers against MPXV than vaccinated and MPXV-naive persons at 1 month postexposure. Neutralizing antibody titers had waned significantly in both groups at 8 months. This study suggests that additional vaccine strategies are needed to elicit a durable humoral response and prevent breakthrough infections.
Self-reported prevalence of tuberculosis: unveiling spatial representation in the districts of Tamil Nadu
Authors: Muniyandi Malaisamy , Mathiyazhagan Kavi , Karikalan Nagarajan
Published: October 2024

Background

The objective of the current study was to estimate the self-reported individual-level crude prevalence and cluster-level adjusted prevalence of TB for the districts of Tamil Nadu and to understand the spatial distribution of TB cases through spatial autocorrelation and hotspot analysis.

Methods

National Family Health Survey (NFHS) data, gathered during 2014–2015 (NFHS-4) and 2019–2021 (NFHS-5), were used in the current study to estimate district-wise, individual-level crude and cluster-level adjusted TB prevalence per 100 000 population in Tamil Nadu. This was illustrated with the help of spatial geographic representation for various districts of Tamil Nadu using SPSS and QGIS software. The spatial autocorrelation and hotspot analysis were performed using Geoda software.

Results

The overall self-reported individual-level crude prevalence of TB was 337 (95% CI 302 to 375) and 169 (95% CI 144 to 197) per 100 000 population, whereas the cluster-level adjusted prevalence of TB was 356 (95% CI 311 to 405) and 184 (95% CI 154 to 219) per 100 000 population in NFHS-4 and NFHS-5, respectively.

Conclusions

This study highlights those geographical areas with high rates of TB prevalence. This information would be useful for the state and district programme managers to identify areas of high TB prevalence where interventions can be focused.
Eosinophil and B-cell dynamics in the milky spots from Schistosoma mansoni-infected mice: comparison with spleen and bone marrow, and extramedullary eosinopoiesis
Authors: Vieira Bruno Marques , Almeida Beatriz Fernandes , Machado Marcelo Pelajo
Published: October 2024

The milky spots (MS) are structures found in the omentum of humans and other vertebrates, representing a fraction of the lymphomyeloid tissue associated with the celom. They majorly consist of B lymphocytes, T lymphocytes, and macrophages. Also found in smaller quantities are mesothelial, stromal, dendritic, and rare mast cells. In an experimental model of Schistosoma mansoni infection, there is significant activation of the omentum and MS, which exhibit numerous eosinophils. Despite being described for many years, the complete profile of cells found in MS and their functions remains largely unexplored. Here, we evaluate the leukocyte populations of the MS in homeostasis and a murine model of S. mansoni infection. The histopathological characterization, phenotypic profile analysis, and characterization of the eosinophilic potential of progenitors and precursors comparing the MS with the spleen and bone marrow showed significant activation of MS in infected mice, with changes in the profile over the analyzed times, showing signs of migration and activation of eosinophils, with local eosinopoiesis and maintenance of the eosinophilic population. In naive mice, B1a and B1b cells make up only a small fraction of B lymphocytes. However, B1b cells expand significantly during infection, peaking at 60 days post-infection (DPI) before stabilizing by 90 DPI. B1a cells also increase initially but decrease over time. The behavior of MS differs from other primary and secondary lymphoid organs, acting as a central lymphoid organ in cavity immunity.
Tailless and filamentous prophages are predominant in marine Vibrio
Authors: Steensen Kerrin , Séneca Joana , Bartlau Nina , Yu Xiaoqian A , Hussain Fatima A , Polz Martin F
Published: October 2024

Although tailed bacteriophages (phages) of the class Caudoviricetes are thought to constitute the most abundant and ecologically relevant group of phages that can integrate their genome into the host chromosome, it is becoming increasingly clear that other prophages are widespread. Here, we show that prophages derived from filamentous and tailless phages with genome sizes below 16 kb make up the majority of prophages in marine bacteria of the genus Vibrio. To estimate prophage prevalence unaffected by database biases, we combined comparative genomics and chemical induction of 58 diverse Vibrio cyclitrophicus isolates, resulting in 107 well-curated prophages. Complemented with computationally predicted prophages, we obtained 1158 prophages from 931 naturally co-existing strains of the family Vibrionaceae. Prophages resembling tailless and filamentous phages predominated, accounting for 80% of all prophages in V. cyclitrophicus and 60% across the Vibrionaceae. In our experimental model, prophages of all three viral realms actively replicated upon induction indicating their ability to transfer to new hosts. Indeed, prophages were rapidly gained and lost, as suggested by variable prophage content between closely related V. cyclitrophicus. Prophages related to filamentous and tailless phages were integrated into only three genomic locations and restored the function of their integration site. Despite their small size, they contained highly diverse accessory genes that may contribute to host fitness, such as phage defense systems. We propose that, like their well-studied tailed equivalent, tailless and filamentous temperate phages are active and highly abundant drivers of host ecology and evolution in marine Vibrio, which have been largely overlooked.