bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparing fatigue and ultimate loads of two- and three-bladed 20 MW floating offshore wind turbines
Authors: Anstock Fabian , Ulrich Drechsel Klaus , Schorbach Vera
Published: November 2024

Two-bladed turbines could reduce costs in the whole turbine’s life cycle. Yet, the wind loads are less well distributed, and the rotor does not have the calm inertia of a rotating plate, like a three-bladed turbine. This paper should serve as a numerical basis to understand how different loads of large 20MW floating two- and three-bladed turbines actually are to enable a better estimation of implications from these loads. The most surprising finding is that the tower base bending loads do not increase for the floating two-bladed turbine compared to the floating three-bladed reference. The main tower excitation, known as the blade-passing frequency, happens two- instead of three times per revolution for a two-bladed turbine. For bottom-fixed turbines, an operation with the tower eigenfrequency close to this excitation causes severe loads, which is more likely for a two-bladed turbine. For most floating turbines, the tower eigenfrequency is much higher and happens to be in a bandwidth that serves two-bladed turbines better than three-bladed ones. However, it was also observed that the issue of tower resonance might, in general, be less critical for floating turbines due to a vast increase in tower damping. The highest increase in loads has been found at the tower top if no load alleviation concept, e.g. a teetering hinge or free-yaw, is utilized. Yaw and main bearing loads did not show any significant increase. The unique parked T-position exhibited a major benefit in storm conditions. The final results indicate that large floating two-bladed wind turbines may offer a valuable economic advantage when compared to three-bladed turbines of equal design maturity.
Applying triple collocation for verifying wind resource measurements and reanalysis data
Authors: Gottschall Julia , Moskal Angela
Published: November 2024

Dual comparisons or dual collocation, respectively, is a standard approach in wind data analysis, and particularly in the wind energy resource assessment context, for comparing and relating two time series from different sources describing the same quantity as e.g. the wind speed at a specific height over a certain period of time. This comparison can be used to validate a data source, or to derive a correction for one of the two datasets. Though being widely used, dual collocation comes with inherent flaws which are partly unknown or ignored. A major problem is that dual collocation requires the definition of a reference in advance. Triple collocation may instead allow for a more objective and comprehensive evaluation, where (three) suitable data sources are available, and possibly help to identify which datasets are most suited to represent the relevant wind resource. In this study, we apply the triple collocation methodology to two typical wind resource assessment test cases. Results are promising in providing more information on the analysed datasets and improving the use of different types of data for wind resource assessment in the future.
Hyperbox method: a design-oriented selection of fatigue load cases for offshore wind turbines
Authors: Pineau H. , Antonutti R. , Martin A. , Guinot F.
Published: November 2024

In offshore wind engineering, efficient and well-targeted environmental condition sampling is key to strike the best compromise between accuracy in load assessment and number of simulations. This is even more challenging for floating offshore wind, because of the increased sensitivity to environmental directionality and wind-wave misalignments compared to fixed-bottom. For the fatigue analysis, the selection of the Design Load Cases (DLCs) for a mastered design process should both capture the synthetic information from large amount of data and remain representative of the environment, considering insights from system responses. Since standards do not provide a detailed approach to achieve the representativity goal, a fatigue DLC selection method answering the above challenges is thus proposed, based on direct exploitation of environmental wind and wave long-term time series. It proceeds through a sequence of iterative binning steps to define an appropriate set of boxes in hyperspace, here called hyperboxes, i.e. discrete multidimensional bins in the environment’s descriptive parametric space. Representative metrics for each variable within the boxes can be either defined from conventional statistical indicators or determined as a function of the expected system fatigue responses. It ultimately produces a compact and representative fatigue DLC list for the integrated load analysis (ILA) task, accounting for system response sensitivities where relevant. Selection performance is assessed against the original distribution for a set of discretization choices, depending on the offshore wind turbine design characteristics. Project-wise, this method is flexible and adjustable for all design phases, allowing to make the most of a few tens up to several thousands of DLCs. Floating and fixed-bottom offshore wind system design iterations benefit from the presented approach from concept to detailed phases, increasing the efficiency of the engineering team and the chances of project success.
Sensor concepts for gear damage detection in wind power drives
Authors: Merkle L , Binanzer L , Häderle P , Dazer M
Published: November 2024

Gearbox failure in offshore wind turbines can be caused by fatigue damages like tooth fank fracture (TFF) or pitting damage. For damage detection in current applications, simple threshold values for vibration amplitudes are used to initiate a shutdown of the wind turbine. At this time significant damage to the gear is already present and an external maintenance is inevitable. The objective of this experimental study is to determine a better sensor concept for detection of gear damage in wind power drives during operation. The damage needs to be detected at a very early stage before the health condition of the gears becomes critical. Evaluation criteria for comparison of sensor concepts include the earliest possible detection of damage, robust and reliable detection under varying operating conditions, as well as practicality and cost-effectiveness. The test results show, vibration measurement in radial direction and in high frequency ranges is most suitable and most robust for pitting detection during operation. With the best sensor concept in place, it is possible to detect gear damage like pitting at a very early stage of 0.3 % pitting size.
Innovative Benchmarking of Offshore Wind O&M Strategies via AIS Data Analysis
Authors: Baumgärtner David , Kaczenski Jonas
Published: November 2024

By analyzing AIS data, this study provides independent insights into the diverse logistic concepts deployed by wind farm operators. The benchmarking framework developed herein facilitates the evaluation of logistic efficiency, resilience, and sustainability, thereby contributing to the identification of best practices in offshore wind operations and maintenance (O&M) logistics.

The methodology encompasses data collection, preprocessing, and analysis phases. By providing a transparent and data-driven mechanism for benchmarking offshore wind O&M logistics, this study aids in the identification of inefficiencies and the formulation of strategies to enhance logistic operations.

The results indicate significant variations in logistic efficiency across different offshore wind farms (OWF), suggesting that the adoption of best practices could lead to substantial improvements.
An analysis of floating wind turbine towing operations using OpenFAST
Authors: Ramachandran R. C. , Serraris JJ , de Ridder EJ , Desmond C. , Murphy J.
Published: November 2024

The floating wind industry is slowly entering the commercialisation phase and array-scale floating wind farms are imminent. Irrespective of the type of floater used, towing operations represent a crucial marine activity required during installation, major repairs and decommissioning phases. Numerical analysis of towing operations is vital for predicting hydrodynamic motions and towing loads, enabling the identification of metocean limits crucial for achieving optimised safe and efficient execution. This paper presents a unique approach to utilise OpenFAST for the examination of towing operations. Compared to other numerical analysis tools available in the market, OpenFAST stands out as a free, open-source tool specifically designed for wind turbine analysis. The study introduces and evaluates an analytical method using OpenFAST, demonstrating its efficacy in modelling towing dynamics, predicting forces and assessing motion responses of a semi-submersible floating wind turbine in varying wave conditions. The numerical simulations are compared against the results from an experimental campaign. The capability of the method in simulating towing dynamics and the prediction of motion responses are discussed.
Assessing the influence of nonlinear mooring restoring forces in the optimization and design of FOWT
Authors: Amaral Giovanni A. , Mas-Soler Jordi , Simos Alexandre N.
Published: November 2024

The design of mooring systems plays a pivotal role in the success of Floating Offshore Wind Turbine (FOWT) projects. This process naturally involves iterations, as design and analysis are intricately linked. Despite the inherent nonlinearity of mooring system restoring forces, many designers opt for employing an equivalent linear mooring system stifness matrix to expedite the optimization process in early design stages. This article aims to underscore the limitations associated with relying on the equivalent linear model when compared to accounting for nonlinear restoring forces during optimization processes. To illustrate this point, a case study was conducted using the reference semi-submersible platform VolturnUS-S. The study considered intermediate to large water depths and addressed three different mooring confgurations: catenary, semi-taut, and taut lines. The analysis focused on several critical aspects, including ofset watch circles, line tensions (including those at the anchors), and a cost estimate based on the different models. The findings indicate that, for catenary-based mooring systems, the linear model remains a good approximation, leading to no significant loss of accuracy in the context of early design stages. As the lines become tauter, however, the nonlinearities become more pronounced and the errors involved in the linear model can reach unacceptable levels.
Modeling of rain-induced erosion of wind turbine blades within an offshore wind cluster
Authors: Binsbergen Diederik van , Verma Amrit , Nejad Amir , Helsen Jan
Published: November 2024

This study investigates the influence of wind turbine wakes on the incubation period of leading-edge erosion in offshore environments within an offshore wind cluster. The analysis is performed on a cluster of 250MW+ offshore wind farms mainly consisting of wind turbines with over 5MW rated power. The incubation time of the leading-edge erosion is determined for each turbine from wind-and-rain statistics, coating properties, and tuned analytical wake models. The wind speed, wind direction, and conditional probability of the rain are determined using 25 years of ERA5 reanalysis data. Droplet size distributions are derived from Best’s analytical distribution, which provides a probability distribution of the rain droplet size for a given rainfall intensity. For each wind turbine, the inflow speed and rotor speed are calculated using the TurboGaussian wake model. In addition, an analytical surface fatigue model is used to estimate the short-term erosion damage rates. By multiplying the short-term erosion damage rate with their respective join probabilities, equivalent damage is obtained the inverse of which will indicate the coating lifetime. The results indicate that variability in the coating lifetime across the wind farms can reach up to 35%. Notably, turbines that are predominantly positioned upstream are found to have the shortest coating lifetimes.
Data-driven modeling of low-frequency hydrodynamic loads
Authors: Stamenov D , Abbiati G , Sauder T
Published: November 2024

This paper presents a data-driven approach for estimating the linear and quadratic transfer functions relating incoming waves to hydrodynamic loads on floaters. The procedure relies on constructing a nonlinear auto-regressive (NARX) surrogate model for forecasting the hydrodynamic loads and a harmonic probing algorithm for extracting the transfer functions of the system. The implemented harmonic probing method is of numerical nature and avoids the use of computationally expensive symbolic coding tools. The method was verified against synthetic data generated from a potential-flow-based numerical model of the INO WINDMOOR 12 MW floater. The main advantage of NARX models is the fexibility of their structure, meaning that they do not presuppose that the nonlinearity of the hydrodynamic load is quadratic, as it is commonly done.
Infrared thermal measurement in power system considering complex circumstances
Authors: Hao Fangzhou , Wang Shaohua , Ling Ying , Zeng Qi
Published: November 2024

Infrared thermal measurement is a vital tool in power systems for monitoring the temperature of electrical equipment without direct contact. This non-invasive technique helps detect hot spots, identify potential issues, and evaluate the performance of power system components. However, the accuracy of the thermal measurement for power system equipment suffers from complex situations and stochastic circumstances. This paper uses a machine-learning-based method to calculate the accurate surface temperature of equipment, which is mainly based on the feedforward network and backpropagation algorithm. At the same time, multiple regression algorithms are implemented and compared. The simulation results and the experiments show that the infrared thermal measurement based on the proposed method reduces the measurement error to 0.1%.
Analysis of heating performance of transverse magnetic inductor at different operating frequencies
Authors: Peng Yonglong , Wang Yiyang , Li Yabin , Wang Yuanhao
Published: November 2024

Traditional induction heating technology has problems such as uneven temperature distribution and the need to improve heating efficiency and accuracy. Horizontal magnetic flux induction heating technology is a new type of induction heating technology with the advantages of energy efficiency, environmental friendliness, and suitability for local workpiece heating. It is widely used in metallurgy, mechanical manufacturing, light chemical industry, and other fields, holding important economic value. This article studies the heating performance of transverse magnetic inductors at different operating frequencies, simplifies the heating process calculation using finite element analysis, selects stainless steel 405 as the heating material, and sets commonly used parameters such as conductivity and magnetic permeability as fixed values, with frequency as the control variable. Using SolidWorks software to establish a model and COMSOL Multiphysics for simulation, simulated three frequencies: 500Hz, 1kHz, and 5kHz. Analyzed the section temperature, current density distribution, and heating efficiency.
A study on the reduction of high-temperature in the high-pressure piping system of civil aircraft
Authors: Xuan Liming , Jiang Liangliang , Liu Jingxuan
Published: November 2024

For the study of the bleed air flow process in high-pressure pipelines, theoretical analysis and numerical simulation were used to investigate the temperature drop problem in the pipelines. The effect of bleed air and ambient temperatures on the performance of temperature drop in high-pressure pipelines was discussed in detail. The performance of pipeline insulation before and after applying the insulation layer was also discussed. The results show that the higher bleed air temperature and lower ambient temperature obviously cause a greater drop in the bleed air temperature drop. The entrance section of the pipeline is approximately five times the l/d range. Applying the insulation layer can effectively reduce the drop in pipeline temperature. Generally, the air insulation layer can reduce the temperature drop of high-pressure pipeline gas by 25%. If further reduction is required, the vacuum insulation layer can be applied.
A remote monitoring method for gateway electric energy meters based on electric energy, voltage and current conservation decomposition
Authors: Wang Chunyu , Liu Jia , Li Helong , Lu Da , Chen Hao
Published: November 2024

A remote monitoring technique for gateway electricity meters is introduced that leverages conservation principles of electric energy, voltage, and current. It aims to tackle issues related to errors in electric energy meters and transformers that are challenging to distinguish, as well as the high costs associated with on-site testing. The ridge regression is used to solve the formulas for bus power and current conservation to obtain gateway metering points’ error and current loops’ error. The voltage loop error is determined through an averaging method, which is then used to calculate the error in electric energy meters. The voltage consistency method is used to synchronize the time bias between gateway electricity meters, ensuring accurate calculations. The analysis results indicate that the proposed method effectively monitors the operating status of gateway electric energy meters and offers greater accuracy compared to benchmarks. This method can timely discover suspected inaccurate electricity meters, aiding in their maintenance and efficient operation.
Introduction to cross-arm T pole tower of 110kV transmission line and design verification of double circuit T pole tower
Authors: Li Chu , Gong Shijie
Published: November 2024

With the development of various fields in China, users have higher and higher requirements for power reliability. In order to improve the reliability of 110 kV transmission lines, a new type of cross-arm T-connection technology came into being. This paper introduces the characteristics of the original T-connection technology and the new T-connection mode of the new T-connection technology, as well as the design verification of the double-circuit T-connection tower, and draws the conclusion that the new T-connection tower model is reasonable and the force of the rod can be effectively configured.
A biomacromolecular additive based on pullulan polysaccharide to enhance the life of lead-acid battery packs in DC systems
Authors: Meng Xuanren , Wang Xiaoming , Lin Xiangyu , Dou Qian
Published: November 2024

With the rapid growth in demand for mobile power, lead-acid batteries still occupy a large market share due to their excellence in energy storage. However, their lifespan is affected by various factors, which limits the application efficiency and environmental friendliness. In this regard, this paper proposes a method to enhance the service life of lead-acid battery packs by applying biomacromolecule additives. A lead-acid battery pack modification method is investigated by introducing chitosan, a natural macromolecule with excellent electrical conductivity and biodegradation properties, into lead-acid batteries. So that the chitosan-modified material forms a stable and protective film on the surface of the battery electrode plate, thereby reducing the analysis of sulphate crystals on the electrode surface. The method of modification of lead-acid battery packs has been studied. Comparative analysis of the experimental data shows that the modified battery pack exhibits lower charge transfer impedance and better electrochemical stability than the traditional lead-acid battery during the cyclic charge/discharge test. Through the cycle charge/discharge test, the energy loss of the battery with biomolecules is 30% lower than that of the unmodified battery, and the number of charge/discharge cycles increases by 60%, which effectively prolongs the service life of the lead-acid battery. The progress of this paper not only has guiding significance for the performance improvement of traditional lead-acid batteries but also provides a significant theoretical and experimental basis for the development and application of environmental friendly battery materials.
Research on control strategy of electric vehicle thermal management system motor
Authors: Liu Chunhui
Published: November 2024

The low efficiency and difficulty in low-temperature heating are the challenges currently faced by the thermal management system of new energy vehicles. A multi-heat source vehicle thermal management system for waste heat cascade recovery and utilization was proposed, and the performance of the vehicle thermal management system was studied through a combination of component testing and one-dimensional simulation. Based on a one-dimensional simulation model, the characteristics of the motor waste heat source are analyzed. The increase in the inlet water temperature of the motor coolant will lead to enhanced heat dissipation of the motor to the air, resulting in a waste of motor waste heat. Based on the results of the analysis, an energy cascade management strategy is constructed. The optimal heating mode is selected by collecting temperature signals such as motors, and the cut-off valve is controlled through logic gates to achieve flexible switching of different modes. The system effectively reduces the energy consumption of thermal management systems, which is of great significance for developing thermal management systems for new energy vehicles.
An energy management method for combined load forecasting of fuel cell ships
Authors: Jiang Jundao , Zou Liang , Liu Xingdou , Pang Shuo , Zhang Li
Published: November 2024

The article proposes an energy management method (EMM) for fuel cell ships, which consists of two parts: load forecasting (LF) and real-time optimized scheduling (RTOS). LF is composed of Long Short-Term Memory neural networks, which are capable of being trained to predict future loads based on historical ship load information. RTOS consists of model predictive control and can allocate energy in real time. Initially, shiploads and battery status are collected in real time, and then LF passes the predicted load sequence to RTOS. RTOS optimizes real-time energy allocation based on the predicted load and the current operating status of two sets of batteries, while meeting system constraints and maintaining the battery SOC at a healthy level, to minimize operational cost consumption. The simulations demonstrate that the EMM can consistently maintain SOC at a healthy level and reduce fuel cell ship operating costs to some extent, thereby improving economic efficiency.
Introduction
Authors: Ballesteros Bernardo
Published: November 2024

The Introduction situates the main themes addressed in the book and outlines the limits of the study. It begins by contextualizing the book’s perspective on the question of early Greek indebtedness to Near Eastern poetry (§1). Next, it justifies a working definition of divine assemblies which is both flexible and minimalistic. They are poetic situations where a group of gods is portrayed together (§2). The sources’ oral and written dimensions have implications: early Greek and Babylonian poems can be studied as performance poetry, and divine assemblies as traditional typical scenes (§3). Approaches to the gods in relation to literature and religion are also introduced. Divine assemblies enhance comparative understanding of early Greek and Babylonian religious thought as expressed in poetry and myth (§4). Finally, the structure of the book is outlined: Part I is devoted to poetic technique and cross-cultural transmission, Part II to narrative theology and divine power (§5).
Poems
Authors: Ballesteros Bernardo
Published: November 2024

The chapter presents an overview of the key Mesopotamian (Sumero-Akkadian) and early Greek poems studied in the book. It offers plot summaries and details on dating, genre, and manuscript evidence and gives initial interpretative directions on the Greek poems. After a general discussion of dates and contexts (§1), it discusses Sumerian poems from the Old Babylonian period, dealing with gods, culture heroes, and the destruction of cities (§2); the Akkadian poems of Atra-ḫasīs, Gilgameš, Anzû, Enūma eliš and Erra and Išum (§3); and the Iliad, the Odyssey, key Homeric Hymns and Hesiod’s Theogony (§4). Relevant distinctions are outlined between different genres, such as narratives of divine praise and heroic narratives. On the Greek side, the chapter interprets the divine sub-plot of the Iliad and the role of the gods in the Odyssey. It also examines in which sense the Theogony and the Hymns are narrative poems.
Structuring the Narrative
Authors: Ballesteros Bernardo
Published: November 2024

The chapter starts the comparative investigation of poetic technique by charting the main scenes of divine assembly considered in the corpora and demonstrating that they fulfil a similar narrative function in Mesopotamian and early Greek narrative poetry. While the chapter maintains a discrete focus on individual traditions and poems, it observes the recurrence and diachronic elaboration of certain structural patterns. Inasmuch as the gods are the ultimate determinants in the mytho-poetic universe, these scenes give shape and structure to the poems by directing attention to plots’ inceptions, developments and resolutions, and by confronting the narrative’s key themes. Systems of divine assemblies afford a synoptic standpoint on each work’s design and narrative discourse. For instance, they set limits to Gilgameš, direct the Iliad’s plot through conflict and suffering, and justify the rise of Marduk and Zeus in Enūma eliš and Hesiod’s Theogony.
Comparing Conventions
Authors: Ballesteros Bernardo
Published: November 2024

This is the first of two chapters on poetic conventions which narrow the comparative focus. It discusses select motifs recurring in Babylonian and early Greek divine assemblies: divine reactions of unrest and fear (§1), sacrificial banqueting (§2), creation (§3), and wrathful withdrawal (§4). It considers how conventional techniques and structural motifs were passed down and elaborated. In both traditions, traditional phraseology and structures serve sophisticated poetic effects. Important thematic differences, to be further explored in Part II of the book, are also highlighted. The Babylonian chief gods, unlike Zeus, are often fearful and uncertain. At the divine banquet, Mesopotamian human actors are closer to the gods than their Greek counterparts. Creation narratives are more prominent in Babylonia, illustrating the sympathetic power of divine collective action and speech. In both traditions, by contrast, withdrawal story-patterns seem best assessed primarily as story-telling motifs rather than reflecting religious rituals securing the agricultural cycle.
Propertius’ Cynthia
Authors: Franklinos T E
Published: November 2024

This book considers the metapoetic and intra- and intertextual habits of Propertius and their relationship with the repetitious amatory discourse that he fashions for himself with his beloved, Cynthia. Where scholarship has tended to treat metaliterary and amatory aspects of Propertius’ poetry as distinct, this volume—focused on Books 3 and 4—argues that Propertius’ discussion of his own poetry and of his relationship to it as an author-figure—his metapoetic commentary—is closely married to, and can be clearly mapped onto, his account of his relationship with Cynthia, especially in Books 1–3. Moreover, it is shown that the elegist’s amorous discourse is constituted of a poetics of repetitiousness that is apt for the articulation of an elegiac relationship that, by its nature, cannot progress: Propertius’ encounters with Cynthia are repetitive, and he mirrors these in his recollection of lexical and thematic aspects of earlier poems in later ones. Each elegy provides a fragmentary glance at Propertius’ relationship and, through repetitions with variation, the poet (re)shapes his readers’ understanding of his amatory discourse. Furthermore, it is argued that, since his beloved is the embodiment of his poetry, Propertius’ account of the vicissitudes of their relationship allows him to articulate the varied transformations of his elegiac corpus; this becomes most significant as the closing cycle of Book 3 appears to end their relationship and to see the beginning of a radical experimentation with the generic bounds of elegy that is expanded in Book 4 and pre-empts aspects of Ovid’s poetic project.
The boundaries of Propertian elegy
Authors: Franklinos T E
Published: November 2024

This chapter treats the expanded—but continued—elegiac discourse of Book 4, and gives an overview of the ways in which Propertius’ intratextual engagement with his own verse and his interaction with the works of other poets (especially Vergil’s Aeneid) allow him further to explore the propria of elegy outside of the confines of the amatory (notably in 4.2, 4.6, 4.9, 4.10), but by no means to the complete exclusion of the latter. It is also shown that, by encouraging his readers to revisit his earlier books through the figures of Horos (4.1), Acanthis (4.5), Cynthia (4.7, 4.8), and Cornelia (4.11), Propertius recasts his prior presentation of his amatory discourse and destabilizes one’s interpretation of it.
Is autophagy always a death sentence? A case study of highly selective cytoplasmic degradation during phloemogenesis
Authors: Michalak Kornel M , Wojciechowska Natalia , Kułak Karolina , Minicka Julia , Jagodziński Andrzej M , Bagniewska-Zadworna Agnieszka
Published: November 2024

Background and Aims

The transformation of sieve elements from meristematic cells, equipped with a full complement of organelles, to specialized transport tubes devoid of a nucleus has long been enigmatic. We hypothesized a strong involvement of various degradation pathways, particularly macroautophagy in this context, emphasizing the importance of autophagic selectivity in the remaining viability of these cells.

Methods

Experiments were performed on pioneer roots of Populus trichocarpa cultivated in rhizotrons under field conditions. Through anatomical, ultrastructural and molecular analyses, we delineate the stages of phloemogenesis and the concurrent alterations in the cytoplasmic composition of SEs.

Key Results

Notably, we observed not only macroautophagic structures, but also the formation of autophagic plastids, the selective degradation of specific organelles, vacuole disruption and the release of vacuolar contents. These events initially lead to localized reductions in cytoplasm density, but the organelle-rich cytoplasmic phase is safeguarded from extensive damage by a membrane system derived from the endoplasmic reticulum. The sieve element ultimately develops into a conduit containing electron-translucent cytoplasm. Eventually, the mature sieve element is a tube filled only by translucent cytoplasm, with sparse organelles tethered to the cell wall.

Conclusions

Although the activation of programmed cell death pathways was postulated, the persistence of sieve elements indicates that protoplast depletion is meticulously regulated by hitherto unidentified mechanisms. This research elucidates the sequential processes occurring in these cells during phloemogenesis and unveils novel insights into the mechanisms of selective autophagy.
Ranking antibody binding epitopes and proteins across samples from whole proteome tiled linear peptides
Authors: McIlwain Sean J , Hoefges Anna , Erbe Amy K , Sondel Paul M , Ong Irene M
Published: November 2024

Introduction

Ultradense peptide binding arrays that can probe millions of linear peptides comprising the entire proteomes of human or mouse, or hundreds of thousands of microbes, are powerful tools for studying the antibody repertoire in serum samples to understand adaptive immune responses.

Motivation

There are few tools for exploring high-dimensional, significant and reproducible antibody targets for ultradense peptide binding arrays at the linear peptide, epitope (grouping of adjacent peptides), and protein level across multiple samples/subjects (i.e. epitope spread or immunogenic regions of proteins) for understanding the heterogeneity of immune responses.

Results

We developed Hierarchical antibody binding Epitopes and pROteins from liNear peptides (HERON), an R package, which can identify immunogenic epitopes, using meta-analyses and spatial clustering techniques to explore antibody targets at various resolution and confidence levels, that can be found consistently across a specified number of samples through the entire proteome to study antibody responses for diagnostics or treatment. Our approach estimates significance values at the linear peptide (probe), epitope, and protein level to identify top candidates for validation. We tested the performance of predictions on all three levels using correlation between technical replicates and comparison of epitope calls on two datasets, and results showed HERON’s competitiveness in estimating false discovery rates and finding general and sample-level regions of interest for antibody binding.

Availability and implementation

The HERON R package is available at Bioconductor https://bioconductor.org/packages/release/bioc/html/HERON.html.
Causal cardiovascular risk factors for dementia: insights from observational and genetic studies
Authors: Kjeldsen Emilie Westerlin , Frikke-Schmidt Ruth
Published: November 2024

The escalating prevalence of dementia worldwide necessitates preventive strategies to mitigate its extensive health, psychological, and social impacts. As the prevalence of dementia continues to rise, gaining insights into its risk factors and causes becomes paramount, given the absence of a definitive cure. Cardiovascular disease has emerged as a prominent player in the complex landscape of dementia. Preventing dyslipidaemia, unhealthy western-type diets, hypertension, diabetes, being overweight, physical inactivity, smoking, and high alcohol intake have the potential to diminish not only cardiovascular disease but also dementia. The purpose of this review is to present our current understanding of cardiovascular risk factors for Alzheimer’s disease and vascular dementia (VaD) by using clinical human data from observational, genetic studies and clinical trials, while elaborating on potential mechanisms. Hypertension and Type 2 diabetes surface as significant causal risk factors for both Alzheimer’s disease and VaD, as consistently illustrated in observational and Mendelian randomization studies. Anti-hypertensive drugs and physical activity have been shown to improve cognitive function in clinical trials. Important to note is that robust genome-wide association studies are lacking for VaD, and indeed more and prolonged clinical trials are needed to establish these findings and investigate other risk factors. Trials should strategically target individuals at the highest dementia risk, identified using risk charts incorporating genetic markers, biomarkers, and cardiovascular risk factors. Understanding causal risk factors for dementia will optimize preventive measures, and the implementation of well-known therapeutics can halt or alleviate dementia symptoms if started early. Needless to mention is that future health policies should prioritize primordial prevention from early childhood to prevent risk factors from even occurring in the first place. Together, understanding the role of cardiovascular risk factors in dementia, improving genome-wide association studies for VaD, and advancing clinical trials are crucial steps in addressing this significant public health challenge.
Sex-related differences in early morphological and clinical outcomes in patients with type A intramural haematoma: an observational cohort study
Authors: Xiao Yutong , Tian Chuan , Hu Kejian , Qian Xiangyang , Shu Chang
Published: November 2024

OBJECTIVES

To investigate sex-based differences in presenting characteristics and early outcomes of type A intramural haematoma.

METHODS

Patients with type A intramural haematoma in an institutional cohort were consecutively enrolled between December 2013 and July 2022. Presenting characteristics, morphological progression and all-cause death during hospitalization were evaluated according to patient sex.

RESULTS

Among 473 patients, 48.0% were female. Females were older (65.9 ± 9.1 vs 58.5 ± 11.5 years, P < 0.001) with larger ascending aortic diameters (52.2 ± 6.6 vs 48.3 ± 6.1 mm, P < 0.001), thicker haematomas (11.5 ± 4.9 vs 9.5 ± 3.4 mm, P < 0.001) and more frequent focal intimal disruptions (45.4% vs 29.7%, P < 0.001). Within 30 days of initial medical therapy, 89.8% of males vs 70.1% of females showed morphological regression or stable condition on repeat computed tomography angiography. The in-hospital mortality was 9.7% in females (n = 22) and 2.8% in males (n = 7). Kaplan–Meier analysis revealed higher early mortality in females (P = 0.002). Multivariable Cox regression showed female sex as an independent risk factor for early death (hazard ratio: 2.8, 95% confidence interval: 1.2–6.8, P = 0.021). Subgroup analysis revealed no heterogeneity according to subgroups including older age (71–90 years), ascending aortic diameter ≥50 mm, presence of focal intimal disruption, presence of pericardial effusion, haematoma thickness ≥11 mm and hypertension.

CONCLUSIONS

Female patients with type A intramural haematoma presented with worse characteristics, higher early morphological progression and an increased risk of early death compared to males.
Genomic insights into key mechanisms for carbon, nitrogen, and phosphate assimilation by the acidophilic, halotolerant genus Acidihalobacter members
Authors: Khaleque Himel Nahreen , Fathollahzadeh Homayoun , Kaksonen Anna H , Valdés Jorge , Vergara Eva , Holmes David S , Watkin Elizabeth L J
Published: November 2024

In-depth comparative genomic analysis was conducted to predict carbon, nitrogen, and phosphate assimilation pathways in the halotolerant, acidophilic genus Acidihalobacter. The study primarily aimed to understand how the metabolic capabilities of each species can determine their roles and effects on the microbial ecology of their unique saline and acidic environments, as well as in their potential application to saline water bioleaching systems. All four genomes encoded the genes for the complete tricarboxylic acid cycle, including 2-oxoglutarate dehydrogenase, a key enzyme absent in obligate chemolithotrophic acidophiles. Genes for a unique carboxysome shell protein, csoS1D, typically found in halotolerant bacteria but not in acidophiles, were identified. All genomes contained lactate and malate utilization genes, but only A. ferrooxydans DSM 14175T contained genes for the metabolism of propionate. Genes for phosphate assimilation were present, though organized differently across species. Only A. prosperus DSM 5130T and A. aeolianus DSM 14174T genomes contained nitrogen fixation genes, while A. ferrooxydans DSM 14175T and A. yilgarnensis DSM 105917T possessed genes for urease transporters and respiratory nitrate reductases, respectively. The findings suggest that all species can fix carbon dioxide but can also potentially utilize exogenous carbon sources and that the non-nitrogen-fixing species rely on alternative nitrogen assimilation mechanisms.
The Fourth Annual Symposium of the Midwest Aging Consortium
Authors: Kim Jinoh , Buffenstein Rochelle , Bronikowski Anne M , Pilar Vanegas Natalia-Del , Rosas Lorena , Agudelo-Garcia Paula , Mora Ana L , Rojas Mauricio , Englund Davis A , LeBrasseur Nathan K , Nunes Allancer , Robbins Paul D , Kohut Marian L , Kothadiya Siddhant , Bardhan Rizia , Camell Christina D , Sturmlechner Ines , Goronzy Jörg J , Yeh Chung-Yang , Lamming Dudley W , Huang Shijiao , Leiser Scott F , Escorcia Wilber , Gill Matthew S , Taylor Jackson R , Helfand Stephen L , Korm Sovannarith , Gribble Kristin E , Pehar Mariana , Blaszkiewicz Magdalena , Townsend Kristy L , McGregor Eric R , Anderson Rozalyn M , Stilgenbauer Lukas , Sadagurski Marianna , Taylor Alicia , McNeill Elizabeth , Stoeger Thomas , Bai Hua
Published: November 2024

The Midwest Aging Consortium (MAC) has emerged as a critical collaborative initiative aimed at advancing our understanding of aging and developing strategies to combat the rising prevalence of age-related diseases. Founded in 2019, MAC brings together researchers from various disciplines and institutions across the Midwestern United States to foster interdisciplinary geroscience research. This report summarizes the highlights of the Fourth Annual Symposium of MAC, which was held at Iowa State University in May 2023. The symposium featured presentations on a wide array of topics, including studies on slow-aging animals, cellular senescence and senotherapeutics, the role of the immune system in aging, metabolic changes in aging, neuronal health in aging, and biomarkers for measuring the aging process. Speakers shared findings from studies involving a variety of animals, ranging from commonly used species such as mice, rats, worms, yeast, and fruit flies, to less-common ones like naked mole-rats, painted turtles, and rotifers. MAC continues to emphasize the importance of supporting emerging researchers and fostering a collaborative environment, positioning itself as a leader in aging research. This symposium not only showcased the current state of aging biology research but also highlighted the consortium’s role in training the next generation of scientists dedicated to improving the healthspan and well-being of the aging population.
Radiolytic support for oxidative metabolism in an ancient subsurface brine system
Authors: Nisson Devan M , Kieft Thomas L , Castillo Julio , Perl Scott M , Onstott Tullis C
Published: November 2024

Long-isolated subsurface brine environments (Ma-Ga residence times) may be habitable if they sustainably provide substrates, e.g. through water-rock reactions, that support microbial catabolic energy yields exceeding maintenance costs. The relative inaccessibility and low biomass of such systems has led to limited understanding of microbial taxonomic distribution, metabolism, and survival under abiotic stress exposure in these extreme environments. In this study, taxonomic and metabolic annotations of 95 single-cell amplified genomes were obtained for one low biomass (103–104 cells/ml), hypersaline (246 g/L), and radiolytically enriched brine obtained from 3.1 km depth in South Africa’s Moab Khotsong mine. The majority of single-cell amplified genomes belonged to three halophilic families (Halomondaceae (58%), Microbacteriaceae (24%), and Idiomarinaceae (8%)) and did not overlap with any family-level identifications from service water or a less saline dolomite aquifer sampled in the same mine. Functional annotation revealed complete metabolic modules for aerobic heterotrophy (organic acids and xenobiotic oxidation), fermentation, denitrification, and thiosulfate oxidation, suggesting metabolic support in a microoxic environment. Single-cell amplified genomes also contained complete modules for degradation of complex organics, amino acid and nucleotide synthesis, and motility. This work highlights a long-isolated subsurface fluid system with microbial metabolism fueled by radiolytically generated substrates, including O2, and suggests subsurface brines with high radionuclide concentrations as putatively habitable and redox-sustainable environments over long (ka-Ga) timescales.
Novel logging while drilling azimuthal laterolog resistivity instrument design for oil-based mud
Authors: Kang Zhengming , Li Xin , Qin Haojie , Li Yongjie , Zhai Ying
Published: November 2024

This paper proposes a novel structure for the logging while drilling azimuthal laterolog resistivity instrument specifically designed for oil-based mud (OBM). The instrument utilizes capacitive coupling to quantitatively evaluate formation resistivity, permittivity, and the standoff between the measuring electrode and the wellbore wall. This innovation addresses the challenges associated with azimuthal resistivity measurement in highly inclined and horizontal wells, while also offering a deeper depth of investigation (DOI). The tool response characteristics and data inversion methodology were analyzed through numerical calculations. Initially, a 3D numerical simulation model of finite element method that incorporates the instrument structure was developed and its accuracy was verified. By adjusting the electrode size, its DOI was optimized to >10 cm. The measurement impedance was examined in relation to varying measurement frequencies, the standoff, and the electrical parameters (resistivity, permittivity) of both the mud and the formation. Then, suitable instrument parameters and effects of formation and OBM were clarified. The simulation results show that the optimum frequency range is 0.1 to 100 MHz. To reduce the impact of standoff, the diameter of the drill collar should be larger than that of the conventional tool. Finally, a deep learning workflow was established, encompassing deep neural network training, parameter optimization, and testing. The accuracy and generalizability of the inversion method were validated using two complex synthetic stratigraphic models. The results of the inversed resistivity and standoff show good consistency with the set values of the two models. System numerical analysis demonstrates that the proposed instrument scheme can effectively address the drilling and formation evaluation requirements for ultra-deep wells and unconventional oil and gas resources, thereby providing a new option for data inversion.
Analytic Moments of TGARCH(1,1) Models with Polynomially Adjusted Densities
Authors: Carnero M Angeles , León Angel , Ñíguez Trino-Manuel
Published: November 2024

This article extends He, Silvennoinen, and Teräsvirta (2008, J Finan Econ, 6, 208–230) and Francq and Zakoïan (2010, GARCH Models) by providing analytical expressions for the moments of the unconditional distribution of the TGARCH(1,1) under alternative specifications for the conditional mean and different skewed distributions for the innovations. We consider polynomially adjusted (PA) densities, such as the PA Logistic, PA hyperbolic secant, and the PA Gaussian, along with the skewed Student-t. Our results show that (i) the main driver of the skewness of the TGARCH(1,1) is the skewness of the innovations, while the excess kurtosis has a comparatively lesser impact. However, both skewness and kurtosis of the innovations significantly affect the TGARCH(1,1) kurtosis; (ii) if the conditional mean is not constant, returns can be asymmetric even if innovations are symmetric; (iii) skewed innovations can generate cross-correlations different from zero, indicating leverage effect, even when the volatility model is symmetric. Finally, we illustrate our theoretical results with an empirical application to stock indices.