bluuebunny/crossref_metadata_2025 huggingface dataset:
Combining imaging mass spectrometry and immunohistochemistry to analyse the lipidome of spinal cord inflammation
Authors: Calvo Ibai , Montilla Alejandro , Huergo Cristina , Martín-Saiz Lucía , Martín-Allende Javier , Tepavcevic Vanja , Domercq María , Fernández José A.
Published: February 2024

Inflammation is a complex process that accompanies many pathologies. Actually, dysregulation of the inflammatory process is behind many autoimmune diseases. Thus, treatment of such pathologies may benefit from in-depth knowledge of the metabolic changes associated with inflammation. Here, we developed a strategy to characterize the lipid fingerprint of inflammation in a mouse model of spinal cord injury. Using lipid imaging mass spectrometry (LIMS), we scanned spinal cord sections from nine animals injected with lysophosphatidylcholine, a chemical model of demyelination. The lesions were demonstrated to be highly heterogeneous, and therefore, comparison with immunofluorescence experiments carried out in the same section scanned by LIMS was required to accurately identify the morphology of the lesion. Following this protocol, three main areas were defined: the lesion core, the peri-lesion, which is the front of the lesion and is rich in infiltrating cells, and the uninvolved tissue. Segmentation of the LIMS experiments allowed us to isolate the lipid fingerprint of each area in a precise way, as demonstrated by the analysis using classification models. A clear difference in lipid signature was observed between the lesion front and the epicentre, where the damage was maximized. This study is a first step to unravel the changes in the lipidome associated with inflammation in the context of diverse pathologies, such as multiple sclerosis.

Graphical abstract
Engineering amino acid residues of pentacyclic triterpene synthases for improving the activity
Authors: Guo Hao , Chen Tongtong , Zhu Hanrong , Wang Huiyan , Huo Yi-Xin
Published: February 2024

Pentacyclic triterpenoids exhibit a wide range of biological activities which have wide applications in the food, cosmetics, and pharmaceutical industries. High-performance chassis strains have been developed for the production of various pentacyclic triterpenoids, e.g., lupane-type and oleanane-type triterpenoids. The production of common pentacyclic triterpenes and their derivatives is limited by the poor activity of typical pentacyclic triterpene synthases (PTSs). However, a general strategy applicable to typical PTSs is still lacking. As typical pentacyclic triterpenes are derived from the baccharenyl cation, engineering the non-active-site residues in the MXXXXR motif might be beneficial for the catalytic efficiencies of typical PTSs by the stabilization of the baccharenyl cation. Here, we develop a general strategy for improving the activity of typical PTSs. As a proof of concept, the activity of three PTSs such as lupeol synthase, β-amyrin synthase, and α-amyrin synthases was significantly increased up to 7.3-fold by site-directed saturation mutagenesis. This strategy could be applied to improve the activity of various typical PTSs.

Key points

• The strategy could be applied to typical PTSs for improving the activity.

• The catalytic activity of typical PTSs was significantly increased.
CRISPR/Cas9-based toolkit for rapid marker recycling and combinatorial libraries in Komagataella phaffii
Authors: Zhou Wei , Li Yuanyi , Liu Guosong , Qin Weichuang , Wei Dongzhi , Wang Fengqing , Gao Bei
Published: February 2024

Komagataella phaffii, a nonconventional yeast, is increasingly attractive to researchers owing to its posttranslational modification ability, strict methanol regulatory mechanism, and lack of Crabtree effect. Although CRISPR-based gene editing systems have been established in K. phaffii, there are still some inadequacies compared to the model organism Saccharomyces cerevisiae. In this study, a redesigned gRNA plasmid carrying red and green fluorescent proteins facilitated plasmid construction and marker recycling, respectively, making marker recycling more convenient and reliable. Subsequently, based on the knockdown of Ku70 and DNA ligase IV, we experimented with integrating multiple DNA fragments at a single locus. A 26.5-kb-long DNA fragment divided into 11 expression cassettes for lycopene synthesis could be successfully integrated into a single locus at one time with a success rate of 57%. A 27-kb-long DNA fragment could also be precisely knocked out with a 50% positive rate in K. phaffii by introducing two DSBs simultaneously. Finally, to explore the feasibility of rapidly balancing the expression intensity of multiple genes in a metabolic pathway, a yeast combinatorial library was successfully constructed in K. phaffii using lycopene as an indicator, and an optimal combination of the metabolic pathway was identified by screening, with a yield titer of up to 182.73 mg/L in shake flask fermentation.

Key points

• Rapid marker recycling based on the visualization of a green fluorescent protein

• One-step multifragment integration and large fragment knockout in the genome

• A random assembly of multiple DNA elements to create yeast libraries in K. phaffii

Graphical Abstract
Online algorithms for ambulance routing in disaster response with time-varying victim conditions
Authors: Shiri Davood , Akbari Vahid , Salman F. Sibel
Published: February 2024

We present a novel online optimization approach to tackle the ambulance routing problem on a road network, specifically designed to handle uncertainties in travel times, triage levels, required treatment times of victims, and potential changes in victim conditions in post-disaster scenarios. We assume that this information can be learned incrementally online while the ambulances get to the scene. We analyze this problem using the competitive ratio criterion and demonstrate that, when faced with a worst-case instance of this problem, neither deterministic nor randomized online solutions can attain a finite competitive ratio. Subsequently, we present a variety of innovative online heuristics to address this problem which can operate with very low computational running times. We assess the effectiveness of our online solutions by comparing them with each other and with offline solutions derived from complete information. Our analysis involves examining instances from existing literature as well as newly generated large-sized instances. One of our algorithms demonstrates superior performance when compared to the others, achieving experimental competitive ratios that closely approach the optimal ratio of one.
Assessing the optimal MRI descriptors to diagnose Ménière’s disease and the added value of analysing the vestibular aqueduct
Authors: Connor Steve , Pai Irumee , Touska Philip , McElroy Sarah , Ourselin Sebastien , Hajnal Joseph V.
Published: February 2024

Objectives

To evaluate the diagnostic performance and reliability of MRI descriptors used for the detection of Ménière’s disease (MD) on delayed post-gadolinium MRI. To determine which combination of descriptors should be optimally applied and whether analysis of the vestibular aqueduct (VA) contributes to the diagnosis.

Materials and methods

This retrospective single centre case-control study evaluated delayed post-gadolinium MRI of patients with Ménièriform symptoms examined consecutively between Dec 2017 and March 2023. Two observers evaluated 17 MRI descriptors of MD and quantified perilymphatic enhancement (PLE) in the cochlea. Definite MD ears according to the 2015 Barany Society criteria were compared to control ears. Cohen’s kappa and diagnostic odds ratio (DORs) were calculated for each descriptor. Forward stepwise logistic regression determined which combination of MRI descriptors would best predict MD ears, and the area under the receiver operating characteristic curve for this model was measured.

Results

A total of 227 patients (mean age 48.3 ± 14.6, 99 men) with 96 definite MD and 78 control ears were evaluated. The presence of saccular abnormality (absent, as large as or confluent with the utricle) performed best with a DOR of 292.6 (95% confidence interval (CI), 38.305–2235.058). All VA descriptors demonstrated excellent reliability and with DORs of 7.761 (95% CI, 3.517–17.125) to 18.1 (95% CI, 8.445–39.170). Combining these saccular abnormalities with asymmetric cochlear PLE and an incompletely visualised VA correctly classified 90.2% of cases (sensitivity 84.4%, specificity 97.4%, AUC 0.938).

Conclusion

Either absent, enlarged or confluent saccules are the best predictors of MD. Incomplete visualisation of the VA adds value to the diagnosis.

Clinical relevance statement

A number of different MRI descriptors have been proposed for the diagnosis of Ménière’s disease, but by establishing the optimally performing MRI features and highlighting new useful descriptors, there is an opportunity to improve the diagnostic performance of Ménière’s disease imaging.

Key Points

• A comprehensive range of existing and novel vestibular aqueduct delayed post-gadolinium MRI descriptors were compared for their diagnostic performance in Ménière’s disease.

• Saccular abnormality (absent, confluent with or larger than the utricle) is a reliable descriptor and is the optimal individual MRI predictor of Ménière’s disease.

• The presence of this saccule descriptor or asymmetric perilymphatic enhancement and incomplete vestibular aqueduct visualisation will optimise the MRI diagnosis of Ménière’s disease.
The recovery of octocoral populations following periodic disturbance masks their vulnerability to persistent global change
Authors: Cant James , Bramanti Lorenzo , Tsounis Georgios , Martínez Quintana Ángela , Lasker Howard R. , Edmunds Peter J.
Published: February 2024

As the major form of coral reef regime shift, stony coral to macroalgal transitions have received considerable attention. In the Caribbean, however, regime shifts in which scleractinian corals are replaced by octocoral assemblages hold potential for maintaining reef associated communities. Accordingly, forecasting the resilience of octocoral assemblages to future disturbance regimes is necessary to understand these assemblages' capacity to maintain reef biodiversity. We parameterised integral projection models quantifying the survival, growth, and recruitment of the octocorals, Antillogorgia americana, Gorgonia ventalina, and Eunicea flexuosa, in St John, US Virgin Islands, before, during, and after severe hurricane disturbance. Using these models, we forecast the density of populations of each species under varying future hurricane regimes. We demonstrate that although hurricanes reduce population growth, A. americana, G. ventalina, and E. flexuosa each display a capacity for quick recovery following storm disturbance. Despite this recovery potential, we illustrate how the population dynamics of each species correspond with a longer-term decline in their population densities. Despite their resilience to periodic physical disturbance events, ongoing global change jeopardises the future viability of octocoral assemblages.
Serendipity in oto-rhino-laryngology
Authors: van Andel Pek , Feenstra Louw , Schmidt Henk G.
Published: February 2024

Introduction

Serendipitous findings are findings that were initially unsought but nevertheless contribute to the development of the discipline. This article reviews eight serendipitous findings in oto-rhino-laryngology important to its advancement.

Method

The following serendipitous findings are discussed: the accidental discovery of the laryngeal mirror and indirect laryngoscopy by Garcia (1854), the invention of direct oesophagoscopy by Kußmaul (circa 1868), Czermák’s (1863) development of diaphanoscopy, the unintentional emergence of bronchography from a clinical error made by Weingartner (1914), adenotomy by Meyer (1869), the discovery of the causes of unbalance related to the vestibular nerve by Flourens (1830), Bárány’s (1914) finding that the semi-circular canal reflex is involved in equilibrium, and the relationship between gastroesophageal reflux and middle-ear infections by Poelmans and Feenstra (2002).

Discussion

Based on these case studies we conclude that serendipity, defined as the art of making an initially unsought find, does not always appear out of nowhere. Often the researcher is already wrestling with a problem for which the serendipitous finding provides a solution. Sometimes the serendipitous finding enables the application of a known solution to a new problem. And sometimes a serendipitous finding is not recognized as such or considered unimportant. Since observations tend to be theory-loaded, having appropriate background knowledge is a conditio sine qua non to elaborate an unanticipated observation.
Mathematik und Zaubern: Welche Karte bleibt übrig?
Authors: Behrends Ehrhard
Published: February 2024

Ein Zauberkunststück gab Anlass zu einem zahlentheoretischen Problem: Wenn n Karten auf spezielle Weise ausgegeben werden, welche Karte bleibt dann übrig? Die Ergebnisse geben Anlass zu interessanten Variationen des Kunststücks.
Applied deep learning in neurosurgery: identifying cerebrospinal fluid (CSF) shunt systems in hydrocephalus patients
Authors: Rhomberg Thomas , Trivik-Barrientos Felipe , Hakim Arsany , Raabe Andreas , Murek Michael
Published: February 2024

Background

Over the recent decades, the number of different manufacturers and models of cerebrospinal fluid shunt valves constantly increased. Proper identification of shunt valves on X-ray images is crucial to neurosurgeons and radiologists to derive further details of a specific shunt valve, such as opening pressure settings and MR scanning conditions. The main aim of this study is to evaluate the feasibility of an AI-assisted shunt valve detection system.

Methods

The dataset used contains 2070 anonymized images of ten different, commonly used shunt valve types. All images were acquired from skull X-rays or scout CT-images. The images were randomly split into a 80% training and 20% validation set. An implementation in Python with the FastAi library was used to train a convolutional neural network (CNN) using a transfer learning method on a pre-trained model.

Results

Overall, our model achieved an F1-score of 99% to predict the correct shunt valve model. F1-scores for individual shunt valves ranged from 92% for the Sophysa Sophy Mini SM8 to 100% for several other models.

Conclusion

This technology has the potential to automatically detect different shunt valve models in a fast and precise way and may facilitate the identification of an unknown shunt valve on X-ray or CT scout images. The deep learning model we developed could be integrated into PACS systems or standalone mobile applications to enhance clinical workflows.
Childhood obesity and adolescent follow-up depressive symptoms: exploring a moderated mediation model of body esteem and gender
Authors: Beltrán-Garrayo Lucia , Larsen Junilla K. , Eisinga Rob , Vink Jacqueline M. , Blanco Miriam , Graell Montserrat , Sepúlveda Ana Rosa
Published: February 2024

Obesity is a well-recognized risk factor for adolescent depressive symptoms, but mediating mechanisms of this association have scarcely been studied. This study is unique in examining an indirect pathway of this link via body esteem (BE) prospectively from childhood (8–12 years) to adolescence (13–18 years). In addition, potential gender moderation was examined. This study utilized data from a case–control study comparing 100 children with and without obesity matched on important confounders (age, gender, and socioeconomic status). Our findings provide support for the mediating role of BE in the link between childhood weight status and adolescent depressive symptoms at a 5-year follow-up. This mediation effect did not differ between boys and girls. The findings suggest the relevance of specifically targeting children’s BE in preventive intervention programs among children with obesity to prevent future mental health problems.
Precursors and Effects of Self-reported Parental Reflective Functioning: Links to Parental Attachment Representations and Behavioral Sensitivity
Authors: Kungl Melanie T. , Gabler Sandra , White Lars O. , Spangler Gottfried , Vrticka Pascal
Published: February 2024

Parental reflective functioning is thought to provide a missing link between caregivers’ own attachment histories and their ensuing parenting behaviors. The current study sought to extend research on this association involving 115 parents, both mothers and fathers, of 5-to-6-year-old preschoolers using the German version of the Parental Reflective Functioning Questionnaire (PRFQ). Our study was the first to combine Adult Attachment Interview classifications of parental attachment, behavioral observations of parental sensitivity and PRFQ ratings while drawing on a sizable father subsample. We found theoretically consistent significant relations between all measures, while our results particularly highlighted the role of dismissing attachment for decreases in parenting quality on both cognitive and behavioral levels as the dismissing status differentially affected specific components of self-reported parental reflective functioning and observed sensitivity. Interestingly, these patterns were largely comparable in mothers and fathers. Exploratory mediation analyses further suggested that decreased parental reflective functioning may partially mediate the relationship between parents’ dismissing attachment and decreased parental sensitivity. Thus, for prevention and intervention programs targeting parental sensitivity and thus children’s long term healthy mental development, the interplay between parental reflective functioning and parents’ own attachment history emerges as a key mechanism. Finally, our study served as a further validation of the PRFQ given the caveat that the pre-mentalizing subscale may need further revision in the German version.
Persistent immune abnormalities discriminate post-COVID syndrome from convalescence
Authors: Sbierski-Kind Julia , Schlickeiser Stephan , Feldmann Svenja , Ober Veronica , Grüner Eva , Pleimelding Claire , Gilberg Leonard , Brand Isabel , Weigl Nikolas , Ahmed Mohamed I. M. , Ibarra Gerardo , Ruzicka Michael , Benesch Christopher , Pernpruner Anna , Valdinoci Elisabeth , Hoelscher Michael , Adorjan Kristina , Stubbe Hans Christian , Pritsch Michael , Seybold Ulrich , Roider Julia ,   The Post COVID Care and KoCo19 study groups
Published: February 2024

Background

Innate lymphoid cells (ILCs) are key organizers of tissue immune responses and regulate tissue development, repair, and pathology. Persistent clinical sequelae beyond 12 weeks following acute COVID-19 disease, named post-COVID syndrome (PCS), are increasingly recognized in convalescent individuals. ILCs have been associated with the severity of COVID-19 symptoms but their role in the development of PCS remains poorly defined.

Methods and results

Here, we used multiparametric immune phenotyping, finding expanded circulating ILC precursors (ILCPs) and concurrent decreased group 2 innate lymphoid cells (ILC2s) in PCS patients compared to well-matched convalescent control groups at > 3 months after infection or healthy controls. Patients with PCS showed elevated expression of chemokines and cytokines associated with trafficking of immune cells (CCL19/MIP-3b, FLT3-ligand), endothelial inflammation and repair (CXCL1, EGF, RANTES, IL-1RA, PDGF-AA).

Conclusion

These results define immunological parameters associated with PCS and might help find biomarkers and disease-relevant therapeutic strategies.
Endothelial dysfunction and cardiovascular risk in post-COVID-19 patients after 6- and 12-months SARS-CoV-2 infection
Authors: Poyatos Paula , Luque Neus , Sabater Gladis , Eizaguirre Saioa , Bonnin Marc , Orriols Ramon , Tura-Ceide Olga
Published: February 2024

Introduction

SARS-CoV-2 infection causes severe endothelial damage, an essential step for cardiovascular complications. Endothelial-colony forming cells (ECFCs) act as a biomarker of vascular damage but their role in SARS-CoV-2 remain unclear. The aim of this study was to assess whether the number of ECFCs and angiogenic biomarkers remained altered after 6 and 12-months post-infection and whether this imbalance correlated with the presence of long-COVID syndrome and other biological parameters measured.

Methods

Seventy-two patients were recruited at different time-points after overcoming COVID-19 and thirty-one healthy controls. All subjects were matched for age, gender, BMI, and comorbidities. ECFCs were obtained from peripheral blood and cultured with specific conditions.

Results

The results confirm the presence of a long-term sequela in post-COVID-19 patients, with an abnormal increase in ECFC production compared to controls (82.8% vs. 48.4%, P < 0.01) that is maintained up to 6-months (87.0% vs. 48.4%, P < 0.01) and 12-months post-infection (85.0% vs. 48.4%, P < 0.01). Interestingly, post-COVID-19 patients showed a significant downregulation of angiogenesis-related proteins compared to controls indicating a clear endothelial injury. Troponin, NT-proBNP and ferritin levels, markers of cardiovascular risk and inflammation, remained elevated up to 12-months post-infection. Patients with lower numbers of ECFC exhibited higher levels of inflammatory markers, such as ferritin, suggesting that ECFCs may play a protective role. Additionally, long-COVID syndrome was associated with higher ferritin levels and with female gender.

Conclusions

These findings highlight the presence of vascular sequela that last up to 6- and 12-months post-infection and point out the need for preventive measures and patient follow-up.
Enhancing biodiesel stability and performance: synthesis and extraction of macauba biodiesel for sustainable engine applications
Authors: Arumugam Sivashankar , Muthaiyan Ravikumar , Dhairiyasamy Ratchagaraja , Rajendran Silambarasan
Published: February 2024

The demand for sustainable fuels has driven research on biodiesel blends’ combustion characteristics and emissions. The study evaluates the performance of macauba and soybean biodiesel blends by analyzing torque, power, and fuel consumption indicators. The effects of leaf extract additives on engine performance are also assessed. Comparing macauba and soybean blends show similar load, brake power, and engine speed trends on response variables. However, slight variations in coefficients and significance levels indicate unique combustion and emission profiles for each blend. Understanding these distinctions is crucial for optimizing engine performance and emission control strategies. Parameters analyzed include brake-specific fuel consumption (BSFC), brake thermal efficiency (BTE), exhaust gas temperature (EGT), carbon monoxide (CO) emissions, hydrocarbon (HC) emissions, oxides of nitrogen (NOx) emissions, smoke opacity, cylinder pressure, heat release rate, and ignition delay. Blends 80% Soy Methyl and 20% Macauba Methyl Biodiesel (BSM20) demonstrates 5–10% superior fuel efficiency, 8–12% higher energy conversion capability, 3–5% lower exhaust temperatures, 10–15% reduced emissions, and 5–8% enhanced efficiency versus other blends and Diesel. It also shows 10–20% lower hydrocarbon and CO emissions, 15–25% reduced NOx, 20–30% lower particulate matter, and more efficient energy release during combustion. Optimizing heat release rate and ignition delay is crucial; BSM20 shows a 10–15% shorter ignition delay. Understanding blend distinctions is key for optimizing performance and emissions. BSM20 blend demonstrates superior fuel efficiency, energy conversion capability, lower exhaust gas temperatures, reduced emissions, and enhanced engine efficiency compared to other blends and Diesel. It also shows lower hydrocarbon, CO, and NOx emissions, reduced particulate matter emissions, and more efficient energy release during combustion. Optimizing heat release rate and ignition delay is crucial for cleaner combustion and improved engine performance.
Bindungsstile, Computerspielen und die vermittelnde Rolle der Emotionsdysregulation
Authors: Neubronner Philipp , Fauth-Bühler Mira
Published: February 2024

Zusammenfassung: Zielsetzung: In der deutschen Gesellschaft gewinnen Computerspiele zunehmend an Bedeutung. Ziel dieser Arbeit ist es, eine kanadische Studie ( Tang et al., 2022 ) zur vermittelnden Wirkung der Emotionsdysregulation auf den Zusammenhang zwischen unsicheren Bindungsstilen (ängstlich und vermeidend) und den Symptomen einer Computerspielstörung in Deutschland zu replizieren. Methode: Für die Untersuchung beantworteten 280 computerspielende Studierende im Alter von 18–41 Jahren Online-Fragebögen zur Ausprägung einer Computerspielstörung, zu unsicheren Bindungsstilen, zur Emotionsdysregulation und zur Computerspielmotivation. Die statistische Auswertung erfolgte mit RStudio. Die Mediatoranalysen wurden mithilfe des PROCESS Makros (Modell 4; Hayes, 2017 ) durchgeführt. Ergebnisse: Die Ergebnisse der Originalstudie konnten repliziert werden. Unsichere Bindungsstile zeigten einen signifikanten Zusammenhang mit der Ausprägung einer Computerspielstörung und einer erhöhten Emotionsdysregulation. Die Emotionsdysregulation vermittelte den positiven Zusammenhang zwischen vermeidender Bindung und der Ausprägung einer Computerspielstörung vollständig und den positiven Zusammenhang zwischen ängstlicher Bindung und der Ausprägung einer Computerspielstörung teilweise. Schlussfolgerungen: Die Ergebnisse legen nahe, dass die Emotionsdysregulation im klinischen Kontext eine größere Beachtung finden sollte.
Deep Structure of Siletzia in the Puget Lowland: Imaging an Obducted Plateau and Accretionary Thrust Belt With Potential Fields
Authors: Anderson M. L. , Blakely R. J. , Wells R. E. , Dragovich J. D.
Published: February 2024

Detailed understanding of crustal components and tectonic history of forearcs is important due to their geological complexity and high seismic hazard. The principal component of the Cascadia forearc is Siletzia, a composite basaltic terrane of oceanic origin. Much is known about the lithology and age of the province. However, glacial sediments blanketing the Puget Lowland obscure its lateral extent and internal structure, hindering our ability to fully understand its tectonic history and its influence on modern deformation. In this study, we apply map‐view interpretation and two‐dimensional modeling of aeromagnetic and gravity data to the magnetically stratified Siletzia terrane revealing its internal structure and characterizing its eastern boundary. These analyses suggest the contact between Siletzia (Crescent Formation) and the Eocene accretionary prism trends northward under Lake Washington. North of Seattle, this boundary dips east where it crosses the Kingston arch, whereas south of Seattle the contact dips west where it crosses the Seattle uplift (SU). This westward dip is opposite the dip of the Eocene subduction interface, implying obduction of Siletzia upper crust at this southern location. Elongate pairs of high and low magnetic anomalies over the SU suggest imbrication of steeply‐dipping, deeply rooted slices of Crescent Formation within Siletzia. We hypothesize these features result from duplication of Crescent Formation in an accretionary fold‐thrust belt during the Eocene. The active Seattle fault divides this Eocene fold‐thrust belt into two zones with different structural trends and opposite frontal ramp dips, suggesting the Seattle fault may have originated as a tear fault during accretion.
MYRIAM: Open‐Source Software to Estimate Torque Variations Associated With Plate‐Motion Temporal Changes
Authors: Espinoza Valentina , Martin de Blas Juan , Iaffaldano Giampiero
Published: February 2024

Tectonic plate motions are a prime constraint on lithosphere dynamics and on the torques acting upon plates. Researchers typically test hypotheses on the controlling torques via forward computer models, which allow accepting or rejecting hypotheses on the basis of the fit of model–output plate velocities to kinematic reconstructions. Such models typically require a significant amount of input information (e.g., tectonic boundaries, structure of the lithosphere, lateral variations of rheology, among others) to appropriately model the tectonic system, and obtain sufficiently–realistic realizations of plate motions. Alternatively, the inverse problem approach takes the difference between the plate torque–balance at two distinct moments in time. This results in an equation in which (a) torques that have not varied through time are canceled out and (b) torques that instead have varied through time are linked to the resulting plate–motion change through a term that accounts for the plate shape and the rheology of the underlying asthenosphere. This approach sacrifices the capability to describe the different individual forces/torques acting upon a plate. Instead, it focuses on determining torque temporal variations, which significantly reduces the amount of input knowledge required. In this technical note we introduce MYRIAM, an open–source software that implements such an inverse approach. MYRIAM takes plate–motion temporal changes, and outputs an estimate of the torque variation required upon a plate to generate the input kinematic change. MYRIAM is released as an open–source repository hosted at GitHub, complete with source code and executable files for Windows and Unix–based operating systems.
Detachment Fault‐Hosted Subduction Re‐Initiation of the (Ultra)Slow‐Spreading Western Neo‐Tethys in the Jurassic
Authors: Liu Tong , Liu Chuan‐Zhou , Wu Fu‐Yuan , Topuz Gültekin , Wan Bo , Wang Jia‐Min , Chen Guohui
Published: February 2024

Subduction initiation in oceans is key to understanding regional and global plate tectonics and ocean basin dynamics; however, its genetic mechanism is still enigmatic. The most famous model that predicts intraoceanic subduction initiation along transform faults or fracture zones (i.e., the Subduction Initiation Rule) has been widely used to explain arc‐like geochemical signatures within the Neo‐Tethyan ophiolites, but fails to account for the speculation and/or calculation of a sub‐parallel relationship between the Jurassic subduction zones and paleo ridges of the western Neo‐Tethys. Here, we propose a ridge‐parallel detachment fault‐hosted subduction re‐initiation model for the Jurassic western Neo‐Tethys. Based on field geological and geochemical evidence, we show that the Refahiye ophiolite in the İzmir–Ankara–Erzincan suture of northern Turkey has diagnostic characteristics indicative of (ultra)slow seafloor spreading. An (ultra)slow‐spreading nature also characterizes many Neo‐Tethyan ophiolites from the Alps to Southeast Asia, either at mid‐ocean ridges or in suprasubduction zones. Due to its extremely weak nature, detachment faults were probably a key candidate for the Jurassic intraoceanic subduction re‐initiation of the western Neo‐Tethys in response to far‐field compression after its long‐lived northward subduction. This model is applicable to both the Jurassic and Early Cretaceous ophiolites, but is questionable for the Late Cretaceous ophiolites. Its utility deponds on the kinematics of ancient plate boundaries and compositions of ophiolites. The detachment fault‐hosted subduction re‐initiation model can explain the arc‐like geochemical features of the Jurassic western Neo‐Tethyan ophiolites, but its effect on the structure and component of ophiolites is diverse.
An Introduction to SGTPPR: Sparse Geochemical Tectono‐Magmatic Setting Probabilistic MembershiP DiscriminatoR
Authors: Ueki Kenta , Hino Hideitsu , Kuwatani Tatsu
Published: February 2024

We present a new and easy‐to‐use geochemical tectono‐magmatic setting discriminator to calculate the probability of membership (the Sparse Geochemical Tectono‐magmatic setting Probabilistic membershiP discriminatoR, SGTPPR) that runs in Excel. It outputs the probability of membership for eight different tectono‐magmatic settings (mid‐ocean ridge, oceanic island, oceanic plateau, continental flood basalt province, intra‐oceanic arc, continental arc, island arc, and back‐arc basin) for a given volcanic rock sample based on major and selected trace element contents (SiO2, TiO2, Al2O3, Fe2O3, MgO, CaO, K2O, Na2O, Rb, Sr, Y, Zr, Nb, and Ba). We consider all possible ratios and multiplications of these contents, in addition to the contents themselves, which improves the discrimination accuracy. We use a statistical method called sparse multinomial logistic regression to construct a robust and predictive discrimination model. By imposing the sparsity, only a small number of essential variables are included in the model. The variables are objectively extracted from 287 possible geochemical variables, including all possible ratios and multiplications of the major and trace element contents. The constructed model exhibits a high classification ability, indicating that tectonic discrimination using major and selected trace elements yields a high classification ability when ratios and multiplications are considered. The system outputs the relative weights of the variables (i.e., contents, and ratios and multiplications of contents) of the input geochemical data to the calculated membership probabilities. This information can be used to evaluate and interpret the results. We apply the model to multiple samples of a geological unit, to determine the tectonic setting.
Long‐Term Decreasing of Sea Level Along Latitude of the Luzon Strait During 1993–2020: Surface Versus Subsurface Perspectives
Authors: Wu Baolan , Gan Jianping , Lin Xiaopei , Qiu Bo
Published: February 2024

The sea level in the east of Luzon Strait along the latitudinal band (18°–22°N, 125°–170°E) demonstrates a unique decreasing trend during 1993–2020, with weakening of eddy kinetic energy (EKE), weaker Kuroshio transport and stronger looping pathway in the Luzon Strait. Neither the surface wind forcing (remote Rossby wave and local Ekman convergence/divergence) nor surface buoyancy forcing (heat flux and Ekman thermal advection) could explain the observed sea level and EKE decreasing trend. From the subsurface perspective, by using the observational data analysis and ventilated thermocline theory, we propose that the reduction of mode water in the subsurface ocean contributes to the above changes during the past ∼30 years. The mode water forms primarily in the mid‐latitude and then is carried by the thermocline circulation southwestward after it subducts into the subsurface ocean. It takes ∼5 years for the mode water to arrive at the latitudinal band of Luzon Strait and affect the vertical stratification by changing the slope of thermocline. When the volume of mode water shrinks, the slope of thermocline would flatten, making the upper thermocline lift along the Luzon Strait latitudinal band. Whereafter, the subtropical front weakens, reducing the vertical velocity shear between the surface eastward Subtropical Counter Current and subsurface westward North Equatorial Current and sea level due to the baroclinic adjustment. Besides, the flattened thermocline and weakened vertical velocity shear results in the EKE reduction, which will contribute to the decreasing of sea level due to the weakened eddy‐forcing.
Stratospheric Aerosol Injection Geoengineering Would Mitigate Greenhouse Gas‐Induced Drying and Affect Global Drought Patterns
Authors: Liu Zhaochen , Lang Xianmei , Jiang Dabang
Published: February 2024

Stratospheric aerosol injection (SAI) is suggested as a potential measure for alleviating global warming. The potential effects of SAI on global temperature and precipitation have been extensively discussed, but its impact on drought has received little attention. Based on the simulations from the G6sulfur experiment that employs SAI to reduce the global mean surface temperature from the level of high‐tier forcing (Shared Socioeconomic Pathways SSP5‐8.5) scenario to that of medium‐tier forcing (SSP2‐4.5) scenario, we investigate the drought response to SAI via the standardized precipitation evapotranspiration index. During 2081–2100, SAI effectively offsets the greenhouse gas‐induced aridity trend by increasing the climate water balance at the global scale. Drought duration and severity decrease but drought frequency increases under SAI forcing. Robust wetting responses occur over most regions, especially the Sahara, South America, southern Africa and Australia, while Alaska, Greenland, Southeast Asia, and tropical Africa face enhanced drought due to SAI. Relative to the SSP2‐4.5 scenario, the regional drying and wetting patterns in G6sulfur are remarkably different. Notably, in tropical Africa, SAI reverses the wetting caused by greenhouse gases and induces severer drought. The drought pattern changes are largely due to evaporative demand alterations caused by the vapor pressure deficit response.
Europa's Double Ridges Produced by Ice Wedging
Authors: Cashion M. D. , Johnson B. C. , Gibson H. , Turtle E. P. , Sori M. M. , Melosh H. J.
Published: February 2024

Double ridges are sprawling features observed globally across the icy surface of Europa. They consist of two topographic highs flanking a trough. The topographic relief of the ridges is approximately 100 m, and the ridges extend up to hundreds of kilometers in length. The interior structure and dynamics of Europa's ice shell are currently poorly constrained. Therefore, accurate models for the formation of these prominent surface features can be useful for determining how the ice shell operates. We hypothesize that double ridges form as a result of incremental ice wedging. We use both analytical and numerical finite element models to quantify the deformation that occurs as an ice wedge grows incrementally within the ice shell. We show that incremental growth of the ice wedge results in surface deformation that matches the size and shape of typical Europan double ridges, including their topographic relief and surrounding troughs. We find that as the depth of the ice wedge increases, double ridges become broader and shorter. We explore the possibility of local and non‐local sources for the liquid water that freezes to produce the wedge and ultimately argue in favor of local sources of liquid water within the ice shell.
Impacts of Rainstorm Intensity and Temporal Pattern on Caprock Cliff Persistence and Hillslope Morphology in Drylands
Authors: Shmilovitz Yuval , Tucker Gregory E. , Rossi Matthew W. , Morin Efrat , Armon Moshe , Pederson Joel , Campforts Benjamin , Haviv Itai , Enzel Yehouda
Published: February 2024

Hillslope topographic change in response to climate and climate change is a key aspect of landscape evolution. The impact of short‐duration rainstorms on hillslope evolution in arid regions is persistently questioned but often not directly examined in landscape evolution studies, which are commonly based on mean climate proxies. This study focuses on hillslope surface processes responding to rainstorms in the driest regions of Earth. We present a numerical model for arid, rocky hillslopes with lithology of a softer rock layer capped by a cliff‐forming resistant layer. By representing the combined action of bedrock and clast weathering, cliff‐debris ravel, and runoff‐driven erosion, the model can reproduce commonly observed cliff‐profile morphology. Numerical experiments with a fixed base level were used to test hillslope response to cliff‐debris grain size, rainstorm intensities, and alternation between rainstorm patterns. The persistence of vertical cliffs and the pattern of sediment sorting depend on rainstorm intensities and the size of cliff debris. Numerical experiments confirm that these two variables could have driven the landscape in the Negev Desert (Israel) toward an observed spatial contrast in topographic form over the past 105–106 years. For a given total storm rain depth, short‐duration higher‐intensity rainstorms are more erosive, resulting in greater cliff retreat distances relative to longer, low‐intensity storms. Temporal alternation between rainstorm regimes produces hillslope profiles similar to those previously attributed to Quaternary oscillations in the mean climate. We suggest that arid hillslopes may undergo considerable geomorphic transitions solely by alternating intra‐storm patterns regardless of rainfall amounts.
Assessing Thermospheric Neutral Density Models Using GEODYN's Precision Orbit Determination
Authors: Waldron Z. C. , Garcia‐Sage K. , Thayer J. P. , Sutton E. K. , Ray V. , Rowlands D. D. , Lemoine F. G. , Luthcke S. B. , Kuznetsova M. , Ringuette R. , Rastaetter L. , Berland G. D.
Published: February 2024

This study focuses on utilizing the increasing availability of satellite trajectory data from global navigation satellite system‐enabled low‐Earth orbiting satellites and their precision orbit determination (POD) solutions to expand and refine thermospheric model validation capabilities. The research introduces an updated interface for the GEODYN‐II POD software, leveraging high‐precision space geodetic POD to investigate satellite drag and assess density models. This work presents a case study to examine five models (NRLMSIS2.0, DTM2020, JB2008, TIEGCM, and CTIPe) using precise science orbit (PSO) solutions of the Ice, Cloud, and Land Elevation Satellite‐2 (ICESat‐2). The PSO is used as tracking measurements to construct orbit fits, enabling an evaluation according to each model's ability to redetermine the orbit. Relative in‐track deviations, quantified by in‐track residuals and root‐mean‐square errors (RMSe), are treated as proxies for model densities that differ from an unknown true density. The study investigates assumptions related to the treatment of the drag coefficient and leverages them to eliminate bias and effectively scale model density. Assessment results and interpretations are dictated by the timescale at which the scaling occurs. DTM2020 requires the least scaling (∼−7%) to achieve orbit fits closely matching the PSO within an in‐track RMSe of 7 m when scaled over 2 weeks and 2 m when scaled daily. The remaining models require substantial scaling of the mean density offset (∼30 − 75%) to construct orbit fits that meet the aforementioned RMSe criteria. All models exhibit slight over or under‐sensitivity to geomagnetic activity according to trends in their 24‐hr scaling factors.
A Simple Model of Flood Peak Attenuation
Authors: Paiva Rodrigo C. D. , Lima Stefany G.
Published: February 2024

A simple analytical model was developed for evaluating the attenuation of flood wave peak discharge. The physically‐based model represents the flood wave along its trajectory, based on the diffusive model. Relative peak discharge decreases along the downstream distance according to a power function. The distance is scaled by the attenuation factor related to river hydrodynamics (flow rating, hydraulic diffusivity, celerity, and floodplain storage) and input hydrograph (initial peak discharge, hydrograph volume, and its relative curvature). It also informs the attenuation length, which is a practical indicator of the river distance in which discharge decreases by a given factor. Sensitivity analyses indicate that initial peak discharge, volume, floodplain storage, and slope are the governing factors of attenuation. Model's validity and accuracy were demonstrated by reproducing data from (a) numerical solutions of the Saint‐Venant equations covering a wide range of conditions, (b) 29 observations from 11 historical dam‐breaks, (c) 15 observations of natural floods in seven rivers and (d) a detailed hydrodynamic model. The model errors were generally lower than 10% and not larger than the typical uncertainty of flood observations. The accuracy is higher than simplified empirical models and analogous to a detailed hydrodynamic model that is representative of current practice. The proposed flood attenuation model can be easily applied using a few common parameters and a simple equation in a basic spreadsheet. It is suitable for practical applications such as first assessments of natural and dam‐break floods, engineering design, and analyses of large river networks supported by remote sensing data.
Impacts of Topography‐Driven Water Redistribution on Terrestrial Water Storage Change in California Through Ecosystem Responses
Authors: Zhang Xue‐Yan , Fang Yuanhao , Niu Guo‐Yue , Troch Peter A. , Guo Bo , Leung L. Ruby , Brunke Michael A. , Broxton Patrick , Zeng Xubin
Published: February 2024

Lateral subsurface flow plays an essential role in sustaining the terrestrial ecosystem, but it is not explicitly represented in most Earth System Models. In this study, we implemented an explicit lateral saturated flow model into the E3SM land model (ELM). The model explicitly describes lateral flow in the saturated zone by representing, for each model grid, an idealized hillslope consisting of five hydrologically connected soil columns. We conducted three model experiments driven by 0.125° atmospheric forcing data during 1980–2015 over California using models of the default ELM, a modified version of ELM to enhance infiltration, and the model with the lateral saturated flow model. The simulated runoff, evapotranspiration, and terrestrial water storage anomaly (TWSA) from the three simulations were evaluated against available observations, and the model explicitly representing lateral flow performs best. The new model produces greater gridcell‐averaged evapotranspiration especially over the mountainous regions with moderate relief and seasonally dry climates. Most importantly, it improves the modeled seasonal variations, interannual variabilities, and the recent decadal decline of TWSA. Many of these improvements can be attributed to the enhanced ecosystem resilience to droughts as demonstrated by transpiration increases caused by lateral flow. Model sensitivity experiments suggest that subsurface runoff is most sensitive to the ratio between horizontal and vertical saturated hydraulic conductivity, followed by hillslope planforms (convergent, divergent, and uniform), number of columns, and lower boundary conditions. Future work should effectively characterize hillslopes in global models and explore the long‐term influences of lateral water movement on modeled biogeochemical cycle.
Correlation Structure of Steady Well‐Type Flows Through Heterogeneous Porous Media: Results and Application
Authors: Severino Gerardo , Fallico Carmine , Brunetti Guglielmo Federico Antonio
Published: February 2024

Steady flow toward a fully penetrating well takes place in a natural porous formation, where the erratic spatial variations, and the raising uncertainty, of the hydraulic conductivity K are modeled within a stochastic framework which regards the log‐conductivity, ln K, as a Gaussian, stationary, random field. The study provides second order moments of the flow variables by regarding the variance of the log‐conductivity as a perturbation parameter. Unlike similar studies on the topic, moments are expressed in a quite general (valid for any autocorrelation function of ln K) and very simple (from the computational stand point) form. It is shown that the (cross)variances, unlike the case of mean uniform flows, are not anymore stationary due to the dependence of the mean velocity upon the distance from the well. In particular, they vanish at the well because of the condition of given head along the well’s axis, whereas away from it they behave like those pertaining to a uniform flow. Then, theoretical results are applied to a couple (one serving for calibration and the other used for validation purposes) of pumping tests to illustrate how they can be used to determine the hydraulic properties of the aquifers. In particular, the concept of head‐factor is shown to be the key‐parameter to identify the statistical moments of the random field K.